Handling, treatment, conditioning and storage of

IAEA-TECDOC-775

Handling, treatment,conditioning and storage of

biological radioactive wastesTechnical manual for the management of

low and intermediate level wastesgenerated at small nuclear research centres

and by radioisotope users in medicine, research and industry

C^î^^INTERNATIONAL ATOMIC ENERGY AGENCY /A

The IAEA does not normaHy maintain stocks of reports in this series.However, microfiche copies of these reports can be obtained from

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Orders should be accompanied by prepayment of Austrian Schillings 100,in the form of a cheque or in the form of IAEA microfiche service couponswhich may be ordered separately from the INIS Clearinghouse.

The originating Section of this document in the IAEA was:

Waste Management SectionInternational Atomic Energy Agency

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A-1400 Vienna, Austria

HANDLING, TREATMENT, CONDITIONING AND STORAGE OFBIOLOGICAL RADIOACTIVE WASTES

IAEA, VIENNA, 1994IAEA-TECDOC-775

ISSN 1011-4289

© IAEA, 1994

Printed by the IAEA in AustriaDecember 1994

FOREWORD

The International Atomic Energy Agency (IAEA) has published Technical Reports Seriesand Safety Series documents on radioactive waste management over nearly three decades.These documents have served Member States by presenting basic reference material andcomprehensive surveys of the 'state of the art' technologies applied to radioactive wastemanagement.

The need for assistance in specific waste management problems facing many countrieshas been demonstrated in IAEA activities including technical assistance projects and WasteManagement Advisory Programme (WAMAP) missions. Technical Reports Series and SafetySeries documents usually reflect:

- technological solutions based on experience and resources normally available incountries managing nuclear fuel cycle wastes;

- volumes and activities of radioactive wastes of orders of magnitude greater than thosegenerated in countries without nuclear power.

A series of technical documents has been undertaken especially to fully meet the needsof Member States for straightforward and low cost solutions to waste management problems.These documents will:

- give guidance on making maximum practicable use of indigenous resources;

- provide step-by-step procedures for effective application of technology;

- recommend technological procedures which can be integrated into an overall nationalwaste management programme.

The series entitled 'Technical Manuals for the Management of Low and IntermediateLevel Wastes Generated at Small Nuclear Research Centres and by Radioisotope Users inMedicine, Research and Industry' will serve as reference material to experts on technicalassistance missions and provide 'direct know-how' for technical staff in Member States.Currently, the following manuals have been prepared:

- Minimization and Segregation of Radioactive Wastes

- Storage of Radioactive Wastes- Handling, Conditioning and Disposal of Spent Sealed Sources- Handling and Treatment of Radioactive Aqueous Wastes

- Treatment and Conditioning of Radioactive Solid Wastes- Treatment and Conditioning of Radioactive Organic Liquids- Treatment and Conditioning of Spent Ion Exchange Resins from Research Reactors,

Precipitation Sludges and Other Radioactive Concentrates- Reference Design for a Centralized Waste Processing and Storage Facility.

The objective of this manual is to provide essential guidance to Member States withouta nuclear power programme on handling, treatment, conditioning and storage of wastes thatpresent potential biological as well as radiological hazards that are generated in aninstitutional environment. Wastes that are produced outdoors under field conditions are notdealt with, but basic considerations for such wastes are provided in publications from theJoint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. A publicationaddressing wastes from field projects is planned.

The IAEA wishes to express its gratitude to the consultants, G. Guidarelli (Health andMedical Physics Department, Bologna, Italy). S. Mavrogianis (Yale University, USA),C. Griffiths (Medical Physics Department, Royal Hallamshire Hospital, United Kingdom),A.F. Nechaev (V.G. Khlopin Radium Institute, Russian Federation) and J. Holub (CzechRepublic) who completed the original draft in 1993 in conjunction with J.R. Wiley andW. Baehr as the IAEA officers responsible for this work from the Division of Nuclear FuelCycle and Waste Management.

EDITORIAL NOTF

In preparing this document for press, staff of the IAEA have made up the pages from theoriginal manuscript(s). The views expressed do not necessarily reflect those of the governments of thenominating Member States or of the nominating organizations.

The use of particular designations of countries or territories does not imply any judgement bythe publisher, the IAEA, as to the legal status of such countries or territories, of their authorities andinstitutions or of the delimitation of their boundaries.

The mention of names of specific companies or products (whether or not indicated as registered)does not imply any intention to infringe proprietary rights, nor should it be construed as anendorsement or recommendation on the part of the IAEA.

CONTENTS1. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

1.1. Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71.2. Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71.3. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2. WASTE ARISINGS AND CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . 8

2.1. Use of radionuclides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82.2. Types of wastes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102.3. Radiologically exempt waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3. MANAGEMENT STRATEGIES FOR BIOLOGICALRADIOACTIVE WASTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3.1. Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133.2. Decentralized management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143.3. Centralized management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153.4. Waste minimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

4. PREDISPOSAL WASTE MANAGEMENT TECHNIQUES . . . . . . . . . . . . . . 17

4.1. Pretreatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.1.1. Deactivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.1.2. Packaging for collection or temporary storage . . . . . . . . . . . . . . . 194.1.3. Waste package transfer and record keeping . . . . . . . . . . . . . . . . 224.1.4. Radioactivity survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

4.2. Storage for radionuclide decay . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264.2.1. Basic principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264.2.2. Facility requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264.2.3. Additional considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

4.3. Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304.3.1. Incineration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314.3.2. Maceration/pulverization . . . . . . . . . . . . . . . . . . . . . . . . . . . 324.3.3. Chemical methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324.3.4. Gas sorption/filtration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

4.4. Conditioning of animal carcasses . . . . . . . . . . . . . . . . . . . . . . . . . . . 354.4.1. Conditioning steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354.4.2. Labelling requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

4.5. Storage of conditioned waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395. PREPARATION FOR TRANSPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

5.1. Compliance with transport legislation . . . . . . . . . . . . . . . . . . . . . . . . 425.2. Security and containment in transit . . . . . . . . . . . . . . . . . . . . . . . . . . 435.3. Requirements for refrigerated transport . . . . . . . . . . . . . . . . . . . . . . . 435.4. Documentation/record keeping . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

6. QUALITY ASSURANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

6.1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446.2. Quality assurance programme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456.3. Record keeping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 466.4. Audits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

1. INTRODUCTION

1.1. BACKGROUND

Biological materials that contain radioactive isotopes have many important applicationsin industrial, medical, teaching and research activities related to in vivo and in vitro testing,diagnosis and treatment, agricultural development, and environmental studies. During theproduction and use of these materials, wastes will inevitably arise which must be managedwith particular care due to their potential biological as well as radiological hazards. Thevolume of this waste, which will be referred to in this report as biological radioactive wasteto emphasize both hazards, is small by comparison with most other types of radioactivewaste. Nevertheless a strategy for the management of this waste is necessary in order toensure its safe handling, processing, storage and disposal.

This report deals with wastes that arise outside the nuclear fuel cycle and is directedprimarily to countries without nuclear power programmes. These countries will generallybelong within the IAEA classification of Groups A, B and C. These Groups include MemberStates ranging from those having very limited use of radionuclides (Group A) to those havinga nuclear research center capable of indigenous production of radionuclides (Group C) [1].The report presents practices and procedures for dealing with these wastes as radioactivematerials, with the clear perspective that their properties and potential hazards as biologicalmaterials must be considered in all phases of their management and eventual disposal.

The objective of radioactive waste management is to handle, pretreat, treat, condition,store, transport and dispose of radioactive waste in a manner that protects human health andthe environment without imposing undue burdens on future generations. This objective canbe met without excessive costs by implementing a carefully planned waste managementstrategy using appropriate technology.

Measures to minimize waste production and to segregate wastes arising during the useof radionuclides are most important in waste management. In addition, users of biologicalradioactive materials should be sure that a waste management route exists prior to theproduction of waste from such activities. For example, treatment of animal carcassescontaminated with long lived isotopes at concentrations above exemption limits is difficultif incineration capability is not available. For biological materials it is thus particularlyimportant that an overall management strategy be developed before the waste is generated.

1.2. OBJECTIVE

This report is one of a series of technical manuals providing information and referencematerial for staff in radionuclide user establishments and research centres in Member States.It is intended to provide guidance to Member States hi the handling, treatment andconditioning of biological radioactive materials. Practical guidance is provided for a rangeof available technologies and their individual application to methods of dealing with varioustypes of biological radioactive wastes.

1.3. SCOPE

The types of waste dealt with in this document are restricted to materials containing shortor long lived radionuclides and that are of an organic nature or that otherwise arise in thecourse of medical or biological programmes. The radioactivity associated with those

materials places them in the low or intermediate level radioactive waste category [2].Emphasis is placed on development of a waste management strategy which meets needs andcapabilities of developing IAEA Member States [3]. Practical technical advice is providedon methods of pretreatment, treatment, conditioning, packaging and storage of biologicalradioactive waste. The document also includes requirements for an effective qualityassurance programme for waste management. Information is provided for preparation of thewaste for transportation. Proper treatment and conditioning of biological radioactive wasteas described in this report will produce a stable material that can be disposed of in the samemanner as other low or intermediate level wastes. Disposal is therefore excluded from thisreport, but is described in other IAEA publications [4, 5].

2. WASTE ARISINGS AND CHARACTERISTICS

2.1. USE OF RADIONUCLIDES

The use of radioactive materials in medical diagnosis, treatment and research is veryimportant. In many instances alternative non-radioactive methods are not available or do notprovide the same diagnostic or treatment benefits, or do not give comparable scientificresults. The medical use of radioactive materials encompasses especially:

(a) "in vitro" radioassay procedures using commercially prepared kits in support ofclinical diagnosis and patient treatment.

(b) preparation or dispensing of radiopharmaceuticals for "in vivo" application in supportof clinical diagnosis, follow-up, or therapy; and

(c) radiotherapy using unsealed sources.

The administration of radioactive materials to persons is normally covered by specificregulatory control. General principles of radiation protection in the application ofradionuclides in medicine are described in the Manual on Radiation Protection in Hospitalsand General Practice of the World Health Organization (WHO) [6].

Users of biological radioactive materials in scientific research laboratories, universitiesand other establishments are most commonly involved in monitoring the metabolic or

i environmental pathways associated with compounds as diverse as drugs, pesticides, fertilizersand minerals. Research using radionuclides may involve the following:

I — ̂ ^

(a) Production and labelling of complex compounds which could produce wastecontaining MBq quantities of the relevant radionuclides, i.e. tritium, 32P, 35S, 125I and

(b) Study of metabolic or environmental pathways related to development of new drugs,crop production, environmental protection and field studies such as water assessment.In these studies animals may be used resulting in production of radioactive excreta,carcasses and bedding;

(c) Clinical applications of prepared compounds in which permission may be granted bythe appropriate authorities for work involving humans as well as animals.

The range of applications of radionuclides m medicine, scientific research establishments,universities and the biotechnology industry is continually expanding. Table I lists theradionuclides that are most frequently used in clinical measurements, medical and biologicalresearch.

TABLE I PRINCIPAL RADIONUCLIDES USED IN MEDICINE, CLINICAL MEASUREMENTS ANDBIOLOGICAL RESEARCH

Radionuchde

'H

"C

"F

KNa

"Na

32p

Ms

"Cl

"Ca"Ça

"Se

"Cr

"Co"Co

"Fe

"Ga

"Sr

"Rb

"Sr

«y

'""Kr

Half-life

12 26 a

5960 a

1 83 h

2 6 a

15 h

143d

87 4 d

301 x10= a

164 d4 5 d

838 d

27 7 d

271 7d70 8 d

446d

78 26 h

64Sd

1866d

5052d

64 1 h

13 3 s

Principal application

Clinical measurementsMedical and biological researchLabelling on site

Medical and biological researchLabelling

Positron emission tomography

Clinical measurementsBiological research

Clinical measurements

Clinical therapyMedical and biological research

Clinical measurementsMedical and biological research

Biological research

Biological researchClinical measurements

Medical and biological research


Clinical measurements and biologicalresearch





Clinical therapy

Clinical therapy and measurementsMedical and biological research

Lung ventilation studies

Typical quantityper application

From 5 MBqUp to 100 GBq

Less than 10 GBqUp to 100 MBq

Up to 500 MBq

Up to 50 kBq

Up to 5 GBq

Up to 200 MBqUp to 50 MBq

Up to 5 GBq

Up to 5 MBq

Up to 100 MBqUp to 1 GBq

Up to 500 MBH

Up to 5 MBqUp to 100 kBq

Up to 50 kBq

Up to 50 MBq

Up to 200 MBq

Up to 50 MBq

Up to 500 MBq

Up to 300 MBq

Up to 300 MBq

Up to 2 GBq

Typical wastecharacteristics

Solid liquidOrganic solvents

Solid, liquidSolvent exhaled CO,

Solid, liquid

Liquid effluents

Liquid effluents

Solid, liquid effluents


Solid, liquid

Mainly solidSome liquid

Solid, liquid

SolidMainly liquideffluents


SolidMainly liquideffluents

SolidLiquid effluents

Solid liquid

Solid, liquid

Solid, liquid

Solid, liquid

Gaseous

Possible modes oftreatment or disposal

BunalDispersionIncineration


DispersionIncineration

Dispersion

Dispersion

BunalStorageDispersion

BurialDispersion

BunalDispersion

DispersionBurial


DispersionIncinerationBunal

BurialDispersion


IncinerationDispersion

BunalDispersion




Dispersion

TABLE I (cont)

Rad K.-nuchde

"Nb

Te

'"In

m,

,,5[

"'I

">Sn

'"Xe

IJ1Sm

K1IJ,

""Hg

""Hg

Half-life

35 Öd

602 h

2 8 d

13 3 h

60 d

804d

155 Od

525d

1 929 d

3d

644h

4f i6d

Pnncipal application



Clinical measurementsMéditai and biological research

Medical and biological researchClinical measurements

Clinical measurementsMedical and biological research

Clinical measurementsClinical therapyMedical and biological research



Clinical Therapy

Clinical Measurements


Biological research

Typical quantityper application

Up to 500 MBq

Up to 1 GBq

Up to 500 MBq

Up to 500 MBq

Up to 500 MBqUp to 500 MBq

Up to 500 MBqUp to 10 GBqUp to 500 MBq

Up to 500 MBq

Up to 400 MBq

Up to 8 GBq

200 MBq

Up to 50 MBq

Up to 50 MBq

Typical wastecharacteristics

Solid liquid

Solid, liquid

Solid liquid

Solid liquid

Solid liquidOccasionally vapor

SolidLiquidVapor

SolidLiquid

Gaseous

Solid, liquid

Solid, liquid

Solid, liquid

Solid, liquid

Possible modes oftreatment or disposal


Storage for decayIncineration

BunalDispersion

Storage for decayIncinerationDispersion

Storage for decayBurial dispersionAdsorption on charcoal

Storage for decayBunalDispersionAdsorption on charcoal

BunalIncinerationDispersion

AtmosphencDispersionAdsorption on charcoal

DispersionStorage for decayIncineration

IncinerationStorage for decayDispersion

BunalDispersion

BunalDispersion

2.2. TYPES OF WASTES

Table II gives a compilation of the general types of biological wastes that may containradionuclides. The inclusion of materials having a biological origin clearly distinguishes thesewastes from the inorganic materials that typically arise within the nuclear fuel cycle. Aprimary example is the waste from research involving animals (Fig. 1). All discharges (i.e.faeces, urine, oral) from animals used hi research involving radioactive materials must beconsidered to be potentially contaminated. The animal cage/container must be treated ascontaminated until monitored and declared free from contamination.

Additional hazards may further affect the handling, treatment or packaging of biologicalradioactive wastes. Such hazards may be caused by sharps1, viral contamination, wastes witha volatile nature or aerosols, and wastes from human or animal sources which are visuallyoffensive.

1 Sharps (sharp objects) are items that are capable of cutting or penetrating, i e blades, needles, glassscraps, etc

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TABLE II. TYPES OF BIOLOGICAL RADIOACTIVE WASTE

I. Solid

2. Liquid

3. Gaseous

wet

dry

damp

aqueous

organic

physiological

exhausts to the atmosphere

exhausts collected on filters

Absorbent materials, tubes/vials withliquids, dressings

Tissues, gloves, disposable plastics,animal bedding, sharps, metallic items,glassware

Human or animal tissues, organs, limbs;animal carcasses, cultures, faeces

Common solutions

Scintillation fluids, solvents

Blood specimens, wound or oraldischarges, urine.)33Xe, 91mKr

From iodinations or handling of othervolatile radionuclides

2.3. RADIOLOGICALLY EXEMPT WASTE

For biological radioactive waste, it should be stressed that the following considerationsare applicable only in terms of radiological hazard and are irrelevant for the management ofany biological hazards that may exist. Exemption of biological radioactive wastes fromradiation regulatory control is unlikely to mean that these wastes are also exempt frombiological waste regulatory control.

There has long been a recognition that if every waste material that contains radionuclideshad to be treated and disposed of as radioactive waste, the quantity of such materials wouldbe large and the cost unnecessarily high. Many materials which contain small amounts ofradionuclides can be shown to have insignificant hazard potential. Their regulation achievesno benefit and it is usually considered to be more appropriate to segregate and exempt themfrom the requirements of regulatory controls. The exemption procedures to allow disposalof small amounts of very low level radioactive wastes from general regulatory controls hasbeen under consideration internationally for many years [7-10].

The IAEA has, in co-operation with OECD/NEA, published a Safety Guide on Principlesfor the Exemption of Radiation Sources and Practices from Regulatory Control in which thebasic principles are established [10]. Two basic criteria are specified for determiningwhether or not a practice or material can be exempted from regulatory control:

individual risks must be sufficiently low as not to warrant regulatory concern; and

radiation protection, including the cost of regulatory control, must be optimized.

Guidance has been given internationally on the application of these principles to disposalof very low level radioactive waste [7]. The responsibility for setting exemption levels iswith the national regulatory authority. Exemption is therefore an administrative procedurewhereby wastes below a certain level of concentration or amount can be deregulated and

11

FIG. 1. Animal carcasses frozen in plastic bags. (By courtesy of G. Guidarelli.)

treated just as if they were not radioactive. Segregation for exemption can be an importantmeans of reducing the magnitude of the waste disposal problem. However, it has to bestressed that waste streams for consideration as exempt wastes must be shown to be belowexempt quantities and concentrations. The exemption option must not be misused.

The Agency is currently developing guidance on the practical application of exemptionprinciples to the wastes arising from the use of radionuclides in hospitals and researchlaboratories. In the meantime, reference may be made to the guidance given in IAEA SafetySeries Nos 89 and 70 [10, 11].

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3. MANAGEMENT STRATEGIES FOR BIOLOGICAL RADIOACTIVE WASTE

3.1. OBJECTIVES

Based on the waste types described in Section 2 and the general considerations inSection 1, a waste management strategy should be developed that best fits the local needs andcircumstances, whilst demonstrating regulatory compliance. A general flow chart formanaging biological radioactive waste is shown in Figure 2.

There are essentially two strategies that may exist, dependent upon the extent of use ofradionuclides within a Member State:

(a) decentralized waste management strategy;(b) centralized waste management strategy.

PRODUCTION OFB I O L O G I C A L

R A D I O A C T I V E H A S T E S

5 E D R E G A T I O N OFI N F E C T I O U S M A ! t l H A L

FIG. 2. Flow chart for managing biological radioactive wastes.

13

A combination of the above may be appropriate, especially if a Member State producesa significant amount of waste that contains long lived radionuclides. A centralized strategywould be recommended for the long lived nuclides, while a decentralized strategy would beadvantageous for short lived radionuclides. In either strategy, control by the regulatoryauthority is required and must be maintained [2].

In developing a waste management strategy, practices and concepts may varyconsiderably from one country to another. The following basic principles should be carefullyconsidered when developing the strategy:

- only proven technologies should be considered, and these must be relevant to the typesand characteristics of the wastes concerned;

- the technologies and the entire waste management system should be applicable to theconditions prevailing in the country. This includes the legal and regulatory structureas well as economic, social and physical conditions. Possible omissions anddeficiencies should also be identified and their relevance carefully considered, i.e.status of the regulatory framework, control authority, environmental surveillance,baseline data, etc.;

- an integrated approach with application of the ALARA principle must be followed.This requires considering the entire sequence of waste management operations fromwaste arisings and waste collection to final disposal, and all the related issues: everyaspect of waste production, packaging, conditioning, storage and preparation fortransportation, including regulatory, socio-political and economic issues. Theinteractions among all these factors should be analyzed and understood before thewaste management strategy is developed, so that all wastes can be safely managed.

3.2. DECENTRALIZED MANAGEMENT

A strategy in which each institution that generates biological radioactive waste alsoperforms all or most of the subsequent steps for managing it would be considereddecentralized. Such a strategy may be appropriate for Member States in IAEA Groups A andB, namely those where only very small quantities of waste arise in a few locations, andwhere there is no infrastructure for producing or handling radioactive materials. In suchcases the necessary expertise for waste management can be developed within the institutionsusing the radionuclides, possibly by the project managers or investigators themselves, or theirdesignated subordinates.

There are a number of advantages for making the individual institution or user responsiblefor "cradle to grave" management of biological radioactive materials:

- the incentives for careful planning of the experimental program to include soundpractices like waste segregation and reduction at the source are more evident to theuser;

- it is easier to retain full traceability of the waste;- the labeling and record keeping requirements can be more easily met;- transport is minimized, so waste packaging demands will not be as great, especially

if the waste is disposed of within the boundary of the premises where it is produced;

14

- the generating establishment retains control and responsibility until the waste can bedischarged as exempt, or a repository becomes available.

A decentralized strategy can be a folly acceptable and cost effective method for themanagement of biological radioactive wastes, but success of the operation is dependent uponthe availability of the necessary technology and local expertise.

Potential disadvantages of the decentralized strategy should also be recognized. Thesebecome more pronounced as greater use is made of radioactive materials, for example as aMember State moves toward Group C, with the need and capability for indigenousproduction of radioisotopes.

The primary disadvantage is lack of standardization, as each institution will develop itsown preferred management strategy. While this is acceptable and cost effective for a fewusers, for many users the system eventually becomes unmanageable. Other potentialdisadvantages are:

- practices are likely to lack the rigor and quality assurance demanded from a centralizedstrategy. State of the art practices that could be realized in a centralized strategy maybe financially or technically unattainable by individual institutions;

- methods of record and document keeping may be inconsistent;

- waste handling, treatment, and conditioning facilities may be duplicated unnecessarily.

3.3. CENTRALIZED MANAGEMENT

This strategy is appropriate for IAEA Group C Member States that already have someinfrastructure for manufacturing and distributing radioactive materials outside the nuclear fuelcycle. However, in some instances it may also be advantageous for Group A and B MemberStates particularly if longer lived radionuclides r-\f- involved. Individual producers ofradioactive waste may not have the necessary incentives, available technology, or expertisein waste management to be able to satisfactorily develop a strategy. If the treatment of smallquantities of waste is not cost effective, it may be appropriate to consider having acentralized waste management facility where the necessary expertise, infrastructure andquality assurance capabilities can be developed. This system requires that wastes from avariety of producers be transported to the central facility for subsequent management. Inmany countries, the national nuclear research organization is the central agency withresponsibility for radioactive waste management, with regulation provided by an appropriategovernment department.

This concept enables the responsibilities of the waste producers and the receiving agencyto be defined as follows:

- the waste receiving agency develops for waste producers the guidance for effectivewaste management and establishes waste acceptance requirements. Waste acceptancerequirements are likely to include physical, chemical, biohazardous and radiologicalcharacteristics, as well as the actual quantity of the waste;

- the producer would be responsible for characterizing each waste in accordance with thereceiver's requirements, and in full compliance with regulations relating to both thebiological and the radiological hazards;

15

- the waste receiving agency would assume complete responsibility for subsequentmanagement of the wastes, including any necessary verification of data provided bythe waste producers; however, the receiving agency usually reserves the right te refuseto accept (and possibly return to the producer) any waste which does not meet theprearranged acceptance criteria;

- the receiver would be responsible for establishing the costs associated with propermanagement of these wastes in full compliance with regulatory controls and would beable to recover these costs by an appropriate charging scheme.

There can be advantages in utilizing a centralized waste management facility:

- a more uniformly characterized waste form is packaged ready for final disposal;- the system can be more rigorously controlled with all the individual waste producers

working to the same protocols;- the larger central facility should be able to achieve more cost effective use of its

technology, i.e. economy of scale;

- by recovering its costs from numerous waste producers, a central facility can affordto use more advanced technology.

3.4. WASTE MINIMIZATION

A comprehensive waste management strategy should include ways to minimize productionof radioactive wastes [12]. Reducing the waste arisings, referred to as source reduction, isthe most effective means of waste minimization. This involves careful planning, design andcontrol of experiments, equipment and facilities. It is especially important to minimize non-essential contact between contaminated and non-contaminated materials.

Specific suggestions for minimizing waste production are as follows:

- avoid contaminating the packaging when unpacking radioactive materials. The non-contaminated packaging can be monitored and disposed of as normal refuse;

- layout of the user's facility should provide decontamination zones for articles and forprevention of the spread of contamination when persons leave a contaminatedlocation;

- spread of radioactive materials during handling, processing, storage, inspection andtransport should be prevented by adequate containment supplemented by appropriateventilation cleaning systems;

- working protocols should be designed so as to minimize the production of contaminatedwastes; in particular animal experiments should involve the minimal use of animalsconsistent with obtaining the required information;

- adequate control should be maintained of the animal facilities to ensure there is nocross-contamination, resulting in excessive production of radioactive carcasses andunnecessary use of animals;

16

- all unnecessary non-radioactive materials should be kept out of controlled areas. Forinstance, tools and other components should be introduced into controlled areas withoutpackaging, pallets or wrappings;

- adequate segregation of \vaste at the point of origin to ensure non-radioactive materialdoes not enter tiie radioactive waste stream;

- containment and packaging of radioactive materials should be designed to maintainintegrity;

- detailed procedures are necessary to minimize production of wastes resultant fromdecontamination procedures;

- apparent advantages of single use, disposable items (including protective clothing)versus reusable items should be evaluated in view of overall waste production.

4. PREDISPOSAL WASTE MANAGEMENT TECHNIQUES

4.1. PRETREATMENT

4.1.1. Deactivation

One of the most important and specific stages of biological radioactive waste managementis deactivation (sterilization). Biological waste must be deactivated of all infectious agentsor reliably determined non-infectious. Generally this is done prior to waste collection. Anumber of methods are applicable for these purposes, including the following:

(a) Steam sterilization

This requires subjecting the waste to pressurized steam for 60 to 90 minutes. Laboratoryware or autoclave bags are placed in the sterilizer chamber, the chamber air is removed andpressurized steam is added to achieve a pressure of 15 Ibs/inch2 (95.8 kPa, whichcorresponds to 121°C). This is a standard setting on most commercial autoclaves. Mostmicrobiologically contaminated laboratory waste are suitable for steam sterilization, but thismethod should not be used where the radioactive content of the waste is volatile during steamtreatment. It is necessary to have an effective quality assurance programme for the autoclaveto ensure it is achieving the necessary temperature and holding it for the required time periodto ensure effective sterilization. As with all pressurized, high temperature equipment, theproper safety devices must be in place and maintained in operating condition. This methodis not considered appropriate for most non-microbial pathogens, animal carcasses or parts.

(b) Chemical disinfection

An appropriate solution of oxidizer (potassium permanganate, sodium hypochlorite orbleach) should be poured in a container holding the item(s) intended for disinfection. Thelid should be closed over the opening of the container and it should be left to standovernight. The container is inverted in a sink to drain off any solution. Activity to the drainshall be accounted for. This method is useful for laboratory ware or similar materials, butit is not suitable for pathological wastes and animal carcasses or parts.

17

(c) Dry heat

The biological radioactive waste is subjected to dry heat sterilization in a thermostaticallyconuolled oven This method achieves sterilization by high temperature coagulation ofproteins, typically at temperatures of 160°C. It is important that the entire load reaches thetemperature of 160°C and that the temperature is maintained for one hour. This may requireup to three hours to sterilize a batch of waste. Quality control of the use of dry heatsterilization is achieved by the use of commercially available indicators, for exampleBrowne's sterilizer control tubes, that undergo a permanent colour change to provesterilization conditions were obtained (Fig. 3). These indicators should be placed in themiddle of the batch of material to be sterilized. Dry heat sterilization is not appropriate ifvolatile radionuclides might be released.

(d) Prospective methods

Disinfection by intense gamma ray irradiation of biologically infectious wastes fromhospitals, diagnostic and research laboratories, clinics and mortuaries can be considered asone attractive future option for solving the problem of biological radioactive wastesterilization, especially in a central facility. One main advantage of gamma irradiationprocessing is that once a system is installed it should be virtually maintenance free. It is theonly deactivation method that can be considered appropriate for pathological wastes, animalcarcasses and parts.

FIG. 3. Sterilizer control tubes. (By courtesy of C Griffiths )

IS

A relatively high dose irradiation can kill microorganisms hence preventing microbialputrefaction. Subsequently the biological radioactive waste can be stored in a sealedcontainer for years at room temperature (radioactive decay storage), alleviating the need forrefrigerated storage. Unfortunately, gamma irradiation units are not widely available for thispurpose.

4.1.2. Packaging for collection or temporary storage

When selecting packaging for biological radioactive wastes, it is necessary to considerthe different types of waste arisings, and also the future waste treatment method [13].

(a) Liquid wastes

It is necessary to match the overall liquid waste confinement or retention system to theneeds of the establishment, considering not only current requirements, but likelydevelopments in the future [14]. Exempt liquid radioactive wastes can be discharged directlyto an approved drainage/sewage system such as a municipal sewer. In some circumstancesthe biological hazard makes the radioactive waste unsuitable for immediate disposal, hencethe necessity for deactivation prior to discharge. If meeting both sets of disposal criteria,namely radiological and biological, cannot be assured, biological radioactive waste must notbe discharged directly into a drainage/sewerage system.

A range of containment methods can be utilized, from quite simple storage bottles tosophisticated storage tanks, dependent upon the needs of the establishment. This includesbottles or drums constructed of polymeric materials or metal. A sufficient number ofcontainers must be provided so that the mixing of wastes having significantly different hazardpotentials (biological or radiological) can be avoided. Before storing biological radioactivewastes in metal containers, the corrosive nature of the liquid to be contained must beconsidered, along with the duration of the storage time. If the waste requires steam heatsterilization treatment prior to disposal, the container to hold the liquid should be suitable forthis purpose, i.e. a heavy duty polypropylene container resistant to destruction bytemperatures up to 130°C. Glass storage containers should be avoided due to their fragilenature. A quality assurance programme should include audit of reusable liquid storagecontainers to ensure they remain suitable for continued use.

In more sophisticated establishments where large volumes of biological radioactive liquidwastes of similar origin are produced, use of holding tanks may be the preferred method forcontaining liquid wastes prior to discharge. It is advisable to have a minimum of twoholding tanks. One tank can be rilling, while the other tank is subjected to any necessarychemical deactivation and decay storage prior to discharge. In very large establishments,additional holding tanks may be necessary to facilitate segregation of liquid radioactivewastes into short lived, long lived and biologically hazardous.

(b) Solid wastes

Collection of biological radioactive solid wastes from radionuclide users normallyinvolves distribution of a range of suitable containers throughout the working area to receivediscarded active materials [15]. These containers should be lined with primary packaging,i.e. a heavy duty plastic bag. The containers should be brightly coloured (normally yellow)with the radiation symbol clearly displayed so as to distinguish them from bins for inactive

19

wastes. It is advisable to have a range of types of containers for segregation of the differenttypes of solid biological radioactive wastes at the time of production, Due to the biologicalhazard of these radioactive wastes, lidded containers are advised for their collection. Refusecans/bins with foot operated lids are particularly recommended. They should be lined insidewith heavy gauge plastic bags which can be sealed and removed. Waste collections must bescheduled so that biological materials do not deteriorate in the refuse bins.

Plastic bags for containment of biological radioactive waste should meet certainmanufacturing criteria:

- be of a maximum nominal capacity to meet the needs of the establishment;

- meet the performance specification standards of the establishment or an appropriatestandards setting body;

- match the containers or fittings in use in the working areas;

- when destined for steam sterilization, be suitable for this treatment and carry anindicator strip to show that they have been subject to successful treatment;

- be of an appropriate colour to be easily recognized for correct segregation of solidradioactive waste which may be biologically hazardous;

- take into account the final method of disposal.

Special consideration should always be given to the management of contaminated sharpobjects, i.e. needles and syringes, scalpel blades, blood lancets, glass ampoules, etc. Theseitems are usually suitable for management as dry solid radioactive waste, although very smallamounts of liquid might remain inside the needles, for example.

The following requirements should be met when selecting packaging suitable forcontainment of sharps:

- packaging should be puncture resistant and leak proof, even if toppled over ordropped;

- it must be capable of being handled and moved within the working area whilst in usewith minimum danger of the contents spilling or falling out;

- the container should have an aperture which, in normal use, will inhibit removal of thecontents but will ensure that it is possible to place items into the sharps container usingone hand, without contaminating the outside of the container;

- have a firm closure device attached for sealing when the container is no more thanthree quarters full;

- be marked with the words "Danger Contaminated Sharps Only",

Where treatment is by incineration, heavy duty cardboard, waxed cardboard orpolyethylene/polypropylene containers, clearly labelled as sharps containers, should be usedto collect these wastes. Containers should be no more than three quarters filled before

20

sealing. Where there is no incineration facility available, it may be more appropriate tocollect sharps in metal cans of approximately 5 L or 10 L capacity. When filled, the canscan be firmly lidded and subjected to compaction, prior to bulk collection inside a furthercontainer ready for transfer to a landfill disposal site.

(c) Damp wastes

These wastes are to be avoided because the presence of significant moisture can lead toundesirable and possibly dangerous chemical and biological reactions while the waste is instorage or transit. Damp or wet biological material should therefore be drained, de-wateredor dried to the extent possible, consistent with other safety concerns, before it is placed inwaste receptacles. The addition of a moisture sorbent such as vermiculite may beadvantageous. Freezing carcasses and similar remains is recommended.

The use of plastic bags for biological radioactive waste containment has the advantagethat damp wastes will not seep through them and contaminate the floor. A double wrappingwith plastic bags is advisable. Very heavy, wet wastes should not be packaged in plasticbags where this is the only method of containment to be used, due to the possibility ofrupture of the seam of the plastic bag with resultant loss/seepage of contents. Whenavailable, single use disposable plastic containers with lids (volume range 10 L-120 L)should be used. These containers once lidded and sealed are especially useful as they areleak free, even if the container becomes accidentally inverted during further handling.Additionally, the containers have the advantage that they are suitable for incineration infurnaces designed for plastics.

(d) Storage considerations

Appropriate packaging for temporary storage is an important part of the overall wastemanagement strategy. Choice of the proper types of materials and package style is necessaryto minimize waste volume, provide reliable containment during storage, facilitate handlingand simplify subsequent treatments. Storage considerations for waste packaging include:

- the nature of the waste to be stored;

- the expected tune period for storage, with the possibility of extended storage;

- any further treatment necessary for the packaged wastes, i.e. deactivation, combustion,shredding, compaction prior to long term storage and/or final disposal;

- further handling and movement requirements that the packaging must withstand loadingwithout sustaining damage or deterioration;

- compliance with any existing national and local safety standards;

- compliance with any packaging requirements of the agency that will undertake finaldisposal of the wastes;

- ease of closure/sealing of the radioactive waste packages to prevent dispersion/seepageof contents;

- ease of labelling of the package for purposes of future traceability of origin andidentification of the waste contents;

21

- ability to contain foul odours and to obscure visually offensive wastes;

- reliability of the packaging, to include assessment of existing quality by the packagingmanufacturers;

- ability of the packaging to withstand, without deterioration, the full range oftemperature variations it is likely to encounter, i.e. ability to withstand freezingwithout becoming brittle and liable to fracture,

4.1.3. Waste package transfer and record keeping

A well designed waste management strategy will enable an establishment to keep recordsthat integrate and document the information obtained in all phases of the waste management.Full traceability of wastes requiring additional treatments prior to storage or disposal isessential if wastes are to be disposed of safely. A key step for such a strategy is that acomplete description of the waste is available when it is collected at the point of origin. Thisessential information can be most conveniently collected by use of appropriate labels affixedto the waste packages or containers (for examples see Figure 4).

The information listed below should be included on the label, and also entered into asystem of clear, permanent, legible records:

- an informative description of the waste- details of its origin- its physical, biological and chemical characteristics- radionuclide inventory- radiation level- package volume and weight- details of other specific hazards, i.e. infectious- further details relevant to additional treatments necessary before the waste is sent for

storage or final disposal- name/signature of responsible person.

Arrangements for collection of radioactive waste packages should reflect the nature andquantity of the wastes to be collected. Packaged frozen animal carcasses or other frozenwastes are often retained by the waste producers in laboratory freezers until final disposalis required (Fig. 1). This is generally convenient as most of the radionuclides used inmedicine and research are relatively short lived, hence periods of storage will be short. Anefficient system of arranged transfer to a refrigerated carrier from the individual laboratoryfreezers, with prompt transfer to an incinerator, is an ideal method for collection andtreatment of frozen wastes, where such arrangements are feasible.

For internal movement of wastes, dedicated trucks, trolleys or wheeled containers suchas galvanized bins can be used to transport the waste from the production to the storage area.Vehicles for waste transfer should be retained solely for the purpose if at all possible.Alternatively they will require monitoring and decontamination before they are used for anyalternative purpose. They should allow waste packages to be easily loaded, secured andunloaded, without causing damage to the packaging, i.e. they should be constructed of asmooth, impervious material, free of any sharp or protruding edges, and easily cleaned.

The largest volumes of biological radioactive wastes are likely to be accumulated in arange of packages, to include plastic bags and containers, sharps containers, polyethylene

TAG NUMBER -L J O D J______________

CAUTION RADIOACTIVE MATERIAL

WASTE TYPE

FLUOR TYPEPH LEVEL _SOLUTION _

RADIONUUIDE

CHEMICALFORM

ACTIVITY(mCQ

PRINCIPAL INVESTIGATOR

(«fin»

I hereby attest to the accuracy of this information and declare that the radioactive waste does notcontain any acftve biological hazards

ÏAGMDBY | print) __________________________________________

DATE SIGNATURE

Department Date

Radioactive Waste For IncinerationPrinciple radioactive contents are -

H-3................C-14..............S-35..............1-125.............

Others(specify)

Signature

TOBL

kBqkBqkBqkBqkBqkBqkBq

Waste will not be collected unless the above information is supplied

IMPORTANT Please restrict isotopes to those listed above andincinerate others only when essential because ol biological hazardsor because scintillant waste is involved

FIG. 4. Typical informative labels.

23

containers and other cans/drums/bottles. These wastes are likely to require transfer to acentral collection point on the premises, and may subsequently be transported to a centralizedwaste management facility. The subject of requirements for transportation of waste outsidethe establishment will be discussed in Section 5.

4.1.4. Radioactivity survey

A good waste management strategy requires provision for measuring the radioactivityassociated with a waste package (i.e. plastic bag, drum or other container). Themeasurement, often called a survey, is an integral part of the waste pretreatment i.e. whenit is first collected, and should be repeated whenever the waste packages are handled ormoved (placed into storage, retrieved, or transported off-site). This serves to protectworkers handling the package, helps prevent accidental spread of contamination, and providesan independent check of the record keeping system.

In surveying a waste package, independent measurements are usually made to determine(1) the radioactivity of the waste itself (reported as dose rate, mSv/h, or disintergration rate,Bq, both of which are measured at a specified distance from the container; and/or isotopiccontent); and (2) any radioactive contamination of the outside surfaces of the package. Theseprocedures are described in the following paragraphs.

Measuring the radioactivity from within the waste itself is important for handling thepackage as well as for planning subsequent treatment and for verifying records. Gammaradiation with energies above 100 keV is easily detected allowing rapid and reliablemeasurements, for example of plastic bags, to be made on a semi-automated basis. Thisequipment is well suited for monitoring of low level, solid wastes from laboratories andmedical use of radionuclides (Fig. 5). Waste containing low energy gamma emitters or thehigh energy beta emitters such as 32P can be quantified using commercially availableinstruments and appropriate means to correct the measured activity for losses due toabsorption and geometry (Fig. 6).

Low energy beta emitters such as tritium are difficult to measure to any degree ofaccuracy. Quantities of such nuclides are best estimated from knowledge of how the wastewas produced, and extrapolating from the quantity of radioactive material used and data ontypical waste arisings.

A survey for transferrable surface contamination is especially important before thepackage is handled or moved. This is best accomplished by physically wiping the containerwith a semi porous material such as filter paper or a cotton swab. If possible, it is best towipe over the entire surface. The wipe material is then checked for radioactivity with asurvey meter. Very sensitive measurements can be made if the wipe is counted by liquidscintillation. For such a measurement the wipe is simply folded and dropped into a standardvial containing the scintillation liquid which is then placed in the counter. A good qualityscintillation counter can count several dozen vials automatically and provide the results inprinted form.

The unexpected presence of radioactive contamination on a waste package often indicatesthat the package itself or one nearby has been breached or physically damaged. Forbiological radioactive waste this could also indicate the possible presence of pathogens on thesurface. In all cases the area around the suspect packages should be barricaded, supervision

24

should be notified, and plans developed to identify the source of contamination and to containit. This is often done by placing the damaged package into a secondary bag or "overpack"container.

FIG. 5. Monitoring bagged waste.

FIG. 6. Survey meter with conversion charts. (By courtesy of C. Griffiths.)

25

4.2. STORAGE FOR RADIONUCLIDE DECAY

4.2.1. Basic principles

Storage for decay is particularly important for biological radioactive wastes, since manyof the radionuclides used in medicine and biology are short lived and the activity of theradioactive wastes produced is well defined. Decay storage is a very efficient and economicwaste management procedure. Figure 1 illustrates typical decay storage of frozen animalcarcasses. For containerized waste Fig. 7a shows an arrangement for adding or removingitems in decay storage, and Fig. 7b shows a simple stacking arrangement for lesser amountsof waste.

Practical experience shows that decay storage is suitable for wastes contaminated byradionuclides with a half-life of less than or equal to about 100 days. Particularly wherelarge volumes of medical radioactive wastes are produced, it may be more convenient topartition the short term decay storage facility to provide areas for storage of wastes accordingto their half-life:

- wastes with a half-life of about 10 h or less;- wastes with a half-life of less than 10 days;- wastes with a half-life of less than about 100 days.

A decay storage period of ten half lives will reduce the initial radioactivity to onethousandth of its original radioactivity, which in many cases means below the limits fordisposal as exempt waste, depending on the local regulatory requirements, (the concept ofexempt levels of radioactivity is presented in Section 2.3). Decay storage to an exempt levelis almost always the preferred waste management option, both scientifically andeconomically. Biological radioactive waste which has been subjected to pretreatment, so thatit is no longer a biological hazard, can be disposed of by this route.

The rules for disposal of exempt waste with municipal refuse, which may be establishedby the local authority or other regulation, must be followed. In places where a wellorganized municipal refuse collection system does not exist, the operator may need to seekthe advice of the waste licensing authority. Decay storage and subsequent disposal asmunicipal refuse require accurate administrative control measures and very careful wastesegregation and activity measurement, both at the origin of waste production and at the endof the decay storage period as described in Section 4.1.4. Waste contaminated withhazardous chemicals must be excluded from disposal as municipal refuse.

4.2.2. Facility requirements

Each Member State should define its policy for storage of biological radioactive wastes.The design of the storage facility for unconditioned as well as for conditioned radioactivewaste is similar and should reflect governmental guidance and regulation, and include thefollowing features [3, 16]:

- the store should be used solely for the purpose of holding radioactive wastes, whichmay or may not be biologically hazardous. It is not permitted to store any materialsother than radioactive waste;

- the store should be constructed of rigid building materials;

26

FIG. 7a. View of the decay storage facility during loading of radioactive waste for decay. (By courtesyofG. Guidarelli.)

FIG, 7b. Drums stacked for storage. (By courtesy of J. Evans, University of Texas.)

27

- it should be well illuminated, either by natural or artificial light. Installation of electriclighting should provide for protection from spark ignition when volatile organic wastesare unavoidably stored, i.e. scintillation counter wastes;

- the store should be physically isolated, well away from areas where potentiallyflammable or explosive materials are located, or where employees or other personsmight receive unnecessary exposure;

- the store should be sited away from routes available for public access, but it should bereadily accessible for transfer of wastes, especially for vehicular traffic if required;

- the store should be appropriately ventilated;- it should be appropriately labelled outside with a radiation symbol and warning of any

other biological hazard. It is recommended that the name of the person responsible forsupervision of the radioactive waste store, along with contact daytime and out of hourstelephone numbers, should also be displayed;

- the store should be of sufficient size to hold, in a well organized way, all of theradioactive wastes requiring storage, with adequate spare capacity to deal withcontingency arrangements;

- the store should have a system for segregation of the various categories of radioactivepackages, i.e. racks, drums or bins for storage of plastic bags of waste. There shouldbe no mixing of wastes destined for different routes of disposal, i.e. to incineration orfor landfill;

- storage of food wastes in the vicinity of the radioactive waste store is to bediscouraged, as this encourages infestation by insects or rodents;

- the store should have an impervious, well drained flooring, preferably with wash downfacilities;

- washing facilities for employees using the store should be provided adjacent to or inclose proximity to it;

- an area for protective equipment and materials for dealing with spills should beprovided at or in the store.

The size and capacity of the store should reasonably reflect its expected inventory. Asimple storage room that provides the above features and is located at the waste-producinginstitution may be adequate for small amounts of waste. Figure 8 illustrates a large,centralized facility.

Some biological radioactive wastes require storage in freezer cabinets or chilled roomsin order to prevent putrefaction. Chilled rooms are only likely to be required whereprolonged periods of storage are necessary or the volume of waste produced is large. Forsmaller volumes and shorter storage times, freezer cabinets are adequate, as they are moreeconomic to purchase, operate and maintain. Freezer cabinets can be cooled eitherelectrically or by use of solid carbon dioxide. Ideally the freezer temperature should bemaintained below -20 °C. An alarm should be installed to warn of mechanical or electricalfailure of frozen storage facilities.

Freezing of biological radioactive waste for storage is not always necessary. In manyinstances, waste can be stored at room temperature using appropriate packaging andpreservatives. Some of these wastes may require deactivation before storage, the methodsfor which are detailed in Section 4.1.1.

28

FIG. 8. Decay storage facility for radioactive -wastes from medical use of radloisotopes, Bologna,Italy

The general requirements for a radioactive waste store should be complied with, wheneither selecting suitable existing premises for a short term radioactive waste store, or whendesigning a purpose-built facility. A careful assessment of both current and possible futureshort term decay storage requirements should be considered. The usual radiologicalprotection requirements should apply regarding handling and storage of potentially activewastes in even the simplest of facilities. Local regulatory controls may require additionaldesign features due to the biological/potential infectious nature of the wastes to be stored, i.e.walls sealed with an impervious paint finish to facilitate easy cleaning for infection controlpurposes.

4.2.3. Additional considerations

(a) Security

A radioactive waste storage facility should be well protected against unauthorized humanintrusion. It should be constructed, operated and maintained in such a way that unauthorizedremoval of radioactive wastes is prevented. An adequate locking mechanism should beprovided to prevent unauthorized access. It is recommended that physical barriers, includingfencing and an intruder alarm system be installed. Should intrusion occur, securityarrangements should assure that an unauthorized removal of waste would be promptlydiscovered and effective measures initiated to recover the missing material

(b) Protection from fire

When assessing the overall safety of a radioactive waste storage facility, it is necessaryto consider the possible consequences of an accidental fire and take steps to minimize its risk.

29

The careful selection of non-flammable construction materials when building the radioactivewaste store will greatly reduce this hazard. The radioactive waste store should not be usedto house any highly flammable or highly reactive materials. Gas or oil fired burners mustnot be used for heating, and any previously existing supply lines for these fuels should becapped at a location well away from the store.

Liaison with the local fire fighting authority is necessary. Their advice should be soughtregarding provision of fire fighting equipment in the vicinity of the radioactive waste store.Potentially flammable wastes requiring storage, i.e. organic scintillation fluids in mini vials,should be adequately sealed in heavy-gauge plastic bags, and stored in metal drums with lids.These flammable wastes should be stored in a specific area of the radioactive waste store thatis physically separated from the other wastes and equipped with a high quality fire detectionand suppression system.

(c) Protection from insects/rodents

Insects and rodents can present a serious threat to containment of packaged radioactivewastes, especially in short term storage facilities where plastic bags may be prevalent.Protection from insect and rodent infestation is particularly relevant where biologicalradioactive wastes are stored. Their consumption and dispersion via insect/rodent excretionscan result in the spread of both radioactive contamination and potentially infectious materials.The insect/rodent control programme for a waste store should be carried out in cooperationwith the local health department or other agency authorized to deal with these problems, andmeet all applicable hygiene requirements.

Insect/rodent infestation problems should be correctly identified, including the magnitudeof the problem. Measures should be taken to reduce the routes of entry of insects androdents into the radioactive waste store. Any defects in construction materials should berepaired. The door to the radioactive waste store should be closely fitting, with gaps at thebottom sealed by a firm bristle or metallic sealing strip. Should areas of food or food wastestorage be located in the vicinity of the radioactive waste store, these should be relocated asthey are a possible encouragement to infestation by insects and rodents. Commerciallyavailable poisons, often in preprepared trays, are available. These should be placed bothwithin and outside the radioactive waste store. Any dead insects or rodents recovered shouldbe monitored and assessed for the presence of radioactivity.

A range of insect and rodent traps are also commercially available. Their use should beconsidered where insect/rodent populations may have developed resistance to chemicalmethods of pest control. Trapping may be preferable to poisoning if there is evidence thatthese intruders are spreading contamination.

4.3. TREATMENT

Wastes that contain long lived radionuclides, or that for other reasons cannot be storedfor radioactive decay and then discharged, must be treated and/or conditioned (Fig. 2).These steps reduce the hazard of the waste by converting it to a stable, non-dispersable formthat is suitable for long term storage or disposal as radioactive waste. The resultant wastepackage, for example cement grout in a 200 L drum, must meet predetermined acceptancecriteria for storage or disposal as specified by the regulatory authority [5].

30

After deactivation or procedures aimed at preventing decomposition of its biologicalcomponents, biological radioactive waste can usually be treated using the same methods asfor non-biological radioactive materials in order to meet the waste acceptance criteria.Extensive publications for treating non-biological wastes already exist, i.e. Refs [17-23].Therefore only brief descriptions of treatment methods for biological radioactive waste arepresented below.

4.3.1. Incineration

Incineration is the preferred method for treating biological radioactive wastes of animalor human origins, as well as organic chemical wastes. The aim of treatment by incinerationis to ensure complete combustion of waste, producing totally sterile residues, with anyemissions from the stack being kept to acceptable environmental standards. The resultingash and off-gas residues are thus fully deactivated chemically (not heavy metals) andbiologically, and a very significant waste volume reduction is achieved. For biologicalradioactive wastes, incineration is the only fully developed technology that is capable ofproviding these advantages. Incineration is recommended as a part of a good wastemanagement strategy, especially where the volume of biological radioactive waste justifiescentralization of the treatment facilities.

Properly controlled, efficient incineration is an advanced and technically sophisticatedtreatment method. Disadvantages inherent in using this technology are the high capital costof the incinerator and off-gas system, and the technical expertise required to operate andmaintain the unit (Fig. 9). For these reasons, incineration may be feasible only at a centralfacility where other wastes in addition to biological wastes can be burned.

Air

Waste Fort

900 °C

Humer

Ash removal

Quench

El

Ash ,Removal

70°C

mm

MOW Jî l îW

—— Fuel

Liquid drain

Washer HEPA filter

FIG. 9. Schematic diagram of typical low level waste incinerator. (By courtesy of Austrian ResearchInstitute, Seibersdorf.)

31

Ensuring complete combustion of the waste and maintaining stack emissions withinacceptable limits (which may be carefully detailed as a part of the operating license) are themain technical difficulties for waste incineration. In addition to containing volatileradionuclides and radioactive particulates, the off-gas system must control the release ofchemically toxic or noxious effluents (HC1, SO2, NOX). Improperly controlled combustioncan produce toxic compounds, like dioxins.

After combustion, radionuclides from the waste will be distributed between the ash, filtersand off-gas, depending on details of the unit's design and operating parameters. As a guide,Table III shows typical percentages of nuclides that may be retained in the ash [24, 25].Purther treatment, such as grouting in 200 L drums, will be required to stabilize theseresidues which will now have much higher radionuclide concentrations per unit volume thanthe original waste. Storage, transport, and final disposal of the stabilized residues is identicalto that of low level wastes of non-biological origin.

TABLE III. RETAINED RADIOACTIVITY IN ASH

Radionuclides3H, 125I, 14C, 35S22Na, 32P, 51Cr, 57Co, 59Fe, 67Ga

^Sr, 47Ca, -"Se, 86Rb

% activity

0- 1

30-80

80 - 100

4.3.2. Maceration/pulverization

In cases where incineration is not available or the volumes of human and animal wastesare so low that it is desirable to treat them as they are produced, it may be feasible to usemaceration/pulverization to render these materials liquid, so that they can be discharged viaa liquid radioactive waste route, including any necessary chemical deactivation to treat thebiological hazard.

The apparatus used for this technique is the same basic construction as a liquidizer usedto render food products into a liquid form. It consists of a lidded containment vessel witha series of high speed rotating blades in the base (Fig. 10). Use of a commercially availableliquidizers designed for the catering industry has the added advantage that its stainless steelconstruction can withstand the addition of chemicals, such as sodium hypochlorite, along withthe water, to achieve both liquidization and chemical disinfection of the waste.

4.3.3. Chemical methods

(i) Mummification

Putrefiable solid biological wastes can be collected in plastic bags. If refrigerated storagespace is not available, it is useful to add vermiculite or diatomaceous earth to absorb anyemanating fluids. The addition of formaldehyde, chlorinated lime or hypochlorite solutionmay also be advantageous. A small amount of dilute formaldehyde will delay decomposition;concentrated formaldehyde (40%) will result in mummification of a small animal carcassafter a period of about one year [26]. Handling formaldehyde is hazardous, and proper

32

FIG 10 Macerator (By courtesy of C. Griffiths )

33

precautions, including good ventilation, are necessary. After mummification, waste can beplaced in the waste drum and the drum filled with cement grout. This method is not apreferred or recommended means of treatment. It is discussed only as an option for MemberStates without incineration capability.

(ii) Dissolution

This is not a strongly recommended treatment method for solid radioactive wastes, butin circumstances where no other suitable alternative treatment is identified, it may have arole. This technique involves the use of concentrated acids or bases (HC1, HNO3, NaOH)to destroy the structure of solid radioactive materials and render them liquid.

The severity of this treatment may also satisfactorily eliminate any biological hazardassociated with the waste. The waste may then be discharged after being neutralized anddiluted if necessary, in compliance with regulations governing both chemical and radioactiveliquid discharges. If the resulting liquid cannot be discharged, then further treatment ̂ thefollowing methods may be appropriate.

(iii) Flocculation/precipitation

For liquid aqueous radioactive waste, the usual chemical treatment methods areprecipitation or a flocculation/precipitation process. In the former method, a change in pHor other chemical condition is used to induce precipitation of the ions (usually the radioactivecomponent) to be removed. The resulting solid and liquid phases are separated by decantingand/or filtering.

In the latter process, insoluble, finely divided, solid materials (i.e. metal hydroxides,oxalates and phosphates) are used to remove the radionuclides by chemically entrapping andadsorbing them onto the solid material or flocculent. This method has several advantagesand is therefore a method of choice for countries with limited activities of this type of wasterequiring disposal. It is a treatment procedure based on well proven conventional equipment,has a relatively low cost, allows process conditions to be changed to accommodate the liquidwaste and can handle a large variety of liquid wastes.

The solid phase resulting from either treatment is frequently mixed with a cement groutto produce a stable material for final disposal.

(iv) Ion exchange

The ion exchange process is a very effective method for decontaminating radioactiveaqueous waste. This process involves exchange of ionic species between the liquid and solidmatrix, whereby the radioactive nuclides become bound to the ion exchange material. Theefficiency of removal of the radioactive contaminant is normally in the range of 102 to 103,and in sophisticated systems can be up to 107. The value of this method has been widelydemonstrated and the technique is well established. Nevertheless, the method exhibits anumber of disadvantages, which reduce its usefulness for direct decontamination of aqueousbiological waste. These disadvantages include difficulties with non-electrolytes, colloids,suspended and dissolved organics, detergents and complexing agents. Ion exchange couldbe an appropriate secondary treatment for aqueous wastes from which organic materials havepreviously been removed. Waste materials from the ion exchange process itself, however,must be included in evaluating its applicability. Spent ion exchange materials are usuallyfixed with cement for final disposal [27].

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(v) Evaporation

Evaporation is suitable for processing most aqueous liquids. In the treatment of low levelwastes, evaporation may be attractive if the total volume to be processed is not large, sincethe equipment required is relatively simple compared with other processes. However, thecost of energy may make evaporation very expensive for large volumes.

When a waste liquid containing severely scaling, foaming or corrosive materials is to beevaporated, pretreatments or combination with other waste treatment methods may bedesirable and a careful design of the evaporator becomes necessary. The maximum volumereduction that can be achieved depends on the amount and the properties of dissolved solidsin the waste.

An overall decontamination factor of more than 104 between condensate (distillate) andthick liquor (concentrate) is generally expected from single-effect evaporators so far as non-volatile radioactive contaminants are concerned, and this figure can be improved by the useof de-entrainment devices. However, the decontamination factor will be reduced by thepresence of volatile radioactive materials such as iodine, tritium and radioactive volatileorganic materials.

4.3.4. Gas sorption/filtration

In many instances, dilution with inactive air and atmospheric dispersal is sufficient to dealwith radioactive gases from inhalation tests. In this case, the radionuclides have a short half-life and are used in relatively small amounts. Gaseous wastes from medical lung ventilationstudies can satisfactorily be exhausted to the atmosphere, either via pipe work out of an openwindow or via a pipe work system with a discharge point above the height of the building.In either case, gaseous re-entry into the building must be avoided.

Volatile radioactive compounds or potentially airborne particulates are handled and usedin fume cabinets in order to provide operator protection, Depending on their characteristicsand concentration, they may be vented outside or trapped in an off-gas system [28]. Filtersand other off-gas traps will be removed or cleaned periodically, and eventually disposed ofeither by incineration or to landfill, again depending on the level of radionuclide activity andthe biological hazard.

Filter types employed should be appropriate to the radioactive gaseous waste to betreated:

(i) HEPA filters (high efficiency particulate air filters) for retention of solid particlesincluding aerosols;

(ii) adsorption or chemisorption of radioiodines on filters charged with either activatedcharcoal or silver impregnated zeolites.

4.4. CONDITIONING OF ANIMAL CARCASSES

4.4.1. Conditioning steps

Animal carcasses, organs, and similar biological waste arisings present special needs forconditioning prior to long term storage or disposal. Research personnel and other generators

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should be strongly encouraged to minimize use of animals due to both the difficulty ofmanaging this waste and to humanitarian concerns. Using short lived radionuclides foranimal experiments will allow their wastes to be frozen for decay storage, with eventualdisposal as non-radioactive material. For animals contaminated with long lived nuclides,incineration is the best option for treatment for the reasons described in Section 4.3.1. Ifneither decay storage nor incineration are appropriate, for example in the event of veryinfrequent experiments requiring long lived isotopes, then immobilization in a cement groutmay be used [21].

For larger animals, the carcass is first treated to halt putrefaction by being immersed ina container of 4% formaldehyde and left to bathe in the solution for a minimum period of48 hours. It is important that formaldehyde is used in an area with a fume exhaustventilation system due to the carcinogenic potential of this liquid. The volume of thecontainer of formaldehyde should be approximately twice the volume of the animal carcass.The animal carcass is removed and drained of excess liquid, before it is immobilized withcement grout. The animal can be loaded into a container and the voids filled by a flow offluid cement slurry or grout. Vibration should be used to ensure good penetration of cementaround the waste. This technique is not recommended for frequent application because itis cumbersome, increases the waste volume considerably, and the formaldehyde solutionwhich may also be contaminated with radioactivity, will require disposal as chen icallyhazardous radioactive waste.

Small animal carcasses and similar biological materials can be directly immobilized ina cement matrix (Figs 11, 12). Two drums of different capacity should be used. The inner

ANIMALCARCASSESi

60 L DRUMPREPARATION

FILLING OFTHE 60 L DRUM

50 mm CONCRETE LAYER I220 L DRUM

PREPARATION

50-100 mmCONCRETE LAYER

INSERTING 60 L DRUMINTO 220 L DRUM

PROVIDING ACONCRETE LINING

BETWEEN

INTERIMSTORAGE

FIG. 11. Flow diagram for conditioning animal carcasses.

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(a) 25 L can (b) Four 25 L cans placed in a 200 L drum

(c) Overgroutmg of the cans

FIG. 12. Embedding of radioactive contaminated carcasses in cement grout. (By courtesy ofG. Guidareili).

drum should be about 60-100 L and the outer drum should be about 220 L. The inner drumshould be prepared by creating a 50 mm concrete layer in the bottom. Dry cement shouldbe poured to obtain a 20 mm layer. The frozen carcasses, without the plastic bags, shouldthen be placed in the drum. Continue to pour dry cement until the carcasses are completelycovered. This operation should continue until the top is almost reached, leaving sufficientspace to create another 50 mm concrete layer at the top of the drum. This drum should beinserted into an outer (approximately 220 L) drum which has been pre-prepared with a

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50-100 mm concrete layer in the bottom. The dram should not be hermetically sealed inorder to permit release of gases resultant from the putrefaction process. Adequate exhaustventilation and environmental monitoring will be required where gaseous releases of tritium,14C or 35S emanate from putrefying wastes. The inclusion of an absorbing agent to surroundthe animal carcass, such as vermiculite or polystyrene foam, which is then incorporated intothe cement matrix, is recommended. This addition traps seepage of organic liquids corningfrom the carcass which could result in more rapid deterioration of the cement.

The main reasons for using a cement grout to immobilize animal carcasses and otherbiological radioactive materials are:

- relative simplicity of handling;- availability of raw materials;- relatively low cost;- high density (shielding) and mechanical strength of products;- compatibility of water with the matrix material.

4.4.2. Labelling requirements

A proper waste identification, labelling and coding system is essential for interim storageas this storage phase may continue for ten years or more. Labelling information shouldinclude details of the isotopes, their chemical and physical nature, weight and volume of thepackage, dates of production and of entering the storage area, details of the waste producer(laboratory or department, hospital or other establishment) external surface dose rate, wastecategory according to the approved waste characterization system, warning of any unusualhazards, and the name of the person responsible for packaging the waste and providing dataabout its contents. This is essentially the same information conveyed upon collection of thewaste (Section 4.1.3) but reflects changes due to its treatment and conditioning, such aschemicals added during treatment and the nature of the final waste matrix.

Packages and containers should be marked "radioactive waste" and should carry theinternational radiation symbol. The label should be completed and signed by the responsibleperson in the area where the waste was produced, according to locally approved anddocumented procedures.

Labels for packages and containers of radioactive waste must be firmly attached so thatthey do not become detached and separated. The printing must be permanent and legible forthe entire storage period. The labels serve several important functions:

- they are a documented record of the entire package contents;

- they detail hazards associated with the package, both in terms of biological, chemicaland radiation parameters;

- they serve to provide evidence of regulatory compliance;

- they provide immediate data as a basis for an intelligent response to accidental releaseor seepage of the package contents;

- the label provides the basis for repository records upon the final disposal of the waste.

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4.5. STORAGE OF CONDITIONED WASTE

General requirements for a waste store have been given in Section 4.2. Decay storageand storage of conditioned waste may be done in one facility or in separate facilitiesdepending on the management strategy. The difference is the expected length of the storageperiod, the robustness of the waste packages and their final disposal routes.

In most countries, the interim storage of conditioned waste is likely to involve long termstorage (some tens of years) whilst awaiting establishment of a repository. Only conditionedsolid waste in selected containers is suitable for such lengthy storage. It is likely that largevolume containers (typically 200 L drums) will be used to hold these wastes [16, 29].

It is recommended that a long term waste storage facility be designed with an adequatecapacity to hold wastes for a period of at least ten years. Planning the facility in terms ofnumber and types of waste packaged to be received during this period is an important partof the waste management strategy. One study has shown, for example, that if 1500 (200 L)drams of conditioned waste were produced over a ten year period, a storage area approaching200 m3 should be constructed, based on the assumption that drums are stacked three unitshigh using simple handling by a fork lift truck (Fig. 13). The possibility of capacityextension should be provided for in the design and location of the facility.

The interim storage facility should be located away from the areas where most personnelare employed, such as process areas, laboratories or offices in order to prevent or minimizeradiation exposure to on-site personnel. It should be built above ground water level andshould not be reached by a potential flood or raised groundwater level. Two facilities thatprovide these features, along with features listed in Section 4.2.2 and are shown in Figures14a and 14b.

A very simple method for interim storage, which may be especially applicable todeveloping countries, is utilization of a large transportable container normally used as ashipping container. Storage using transport containers is easily achievable as an expedientor a longer term measure, perhaps in conjunction with a light building cover. Dependingupon the size of the shipping container, the wastes could be packaged in 40-70 L drums toprovide additional security. Lifting facilities to move the transport container complete withits drums of waste are available, making re-location as a whole to a future repository apossibility (Fig. 15).

A maximum allowable dose rate at the surface of each waste package should be definedfor the interim storage building or locations within the building. The restricted quantities andlow activity associated with biological wastes generally permits contact handling and avoidsthe need for shielding requirements in the store. An exceptionally small quantity of wastemay contain sufficient short lived activity to require some separate decay storage beforecontaci handling is permissible. For routine operation a drum having an average contact doserate above 2 mSv/h would usually not be accepted in a management system for low levelconditioned waste. The recommended dose rate limit outside an interim radioactive wastestorage facility is 2.5 /*Sv/h [16].

Handling equipment in the storage facility should be compatible with the building designand the waste package characteristics, in particular regarding the weight, dimensions andradiation levels. The industrial fork lift truck with drum grab attachment is likely to be themost suitable method for handling this type of waste package (Fig. 13).

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FIG 13 Fork lift truck with drum clamp slip

40

FIG 14a Interim storage facility for conditioned waste in Chile (Lo Aguirre)

FIG 14b Waste store for University of Texas institutions, USA

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FIG. 15. Transportable container as interim storage for conditioned wastes.

Radioactive wastes of non-biological origins may be placed in the store as a matter ofeconomy and to consolidate low level wastes in a single location. In this case the need tosegregate wastes from different sources is a matter of judgement, in keeping with the strategyfor final disposal. The physical and radiological properties of treated and conditioned wastemay be a more important consideration for final disposal than the origin of the waste.

To optimize use of the storage space available, stacking of packages is recommended,although another alternative is to use racks. The ability to retrieve individual packagesshould be maintained, both through the physical arrangement of the packages and via therecord keeping system.

Periodic inspection of waste packages contained in the store should be made inaccordance with a preplanned programme of inspection. Documented contingencyarrangements in the waste store should provide for the use of secondary packaging, i.e. anoverpack, where required due to package deterioration or damage. Waste packages shouldalways be maintained in a condition that ensures that they are suitable for transfer to thepoint of final disposal.

5. PREPARATION FOR TRANSPORT

5.1. COMPLIANCE WITH TRANSPORT LEGISLATION

Transport of biological radioactive waste should be conducted in a way that ensures thesafety, not only of those involved in the transport operation, but also for those who could beaffected as a result of transport operations or of an accident during transport. This meansthat detailed regulations are required for preparing waste to be transported as well as for thecarriers.

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Biological radioactive wastes should be adequately packaged and contained for transportby road, rail or sea, according to current national legislative documents. These nationaldocuments are usually based on international recommendations or agreements, which are inany case valid for international transportation of the wastes. The packaging requirements fortransport of radioactive materials are detailed in IAEA Safety Series No. 6, 1985 Edition (asamended 1990) [30]. This document includes details of general safety principles, activitylimits, testing requirements for package types, storage in transit and test and inspectionprocedures. Drivers transporting radioactive materials have to be suitably trained and carrycontingency plans on the vehicle detailing action to be taken in the event of an accident.

Off-site transport and on-site transfer should be carried out in compliance with anyregulations which specify requirements for handling, shielding, labelling of the waste, dealingwith a spill or other accident scenarios.

For on-site transfer of biological radioactive wastes it may not be necessary to meet allthe formal requirements of the regulations for off-site transport, but the transfer should stillbe made with the same precautions and especially at all times remain under the control ofthe site operator and supervisor. However, the probability of accidents involving releasesduring on-site transfer is diminished and members of the public are unlikely to besignificantly exposed should such an accident occur.

During both off-site transport and on-site transfer of biological radioactive wastes, basichygiene and other safety precautions for handling of biological materials must be observed.

5.2. SECURITY AND CONTAINMENT IN TRANSIT

Radioactive packages should be checked prior to loading onto a vehicle to ensure that thepackaging remains intact and able to withstand transportation. Where any doubt exists, thepackage should be securely overpacked to ensure it retains its contents.

When loading packages onto a vehicle, packages with higher surface radiation dose ratesshould be loaded last, such that they are furthest away from the driver. An inventory of theradioactive consignment should be prepared, which identifies uniquely all of the packagesbeing transported, so that any theft or loss of packages would be readily realized.

It is important to secure the load in the vehicle in order to prevent the packages fromshifting during transport, as this may damage them. Various methods of securing the loadcan be utilized, to include the use of cages, tie down facilities or containment nets.

Once biological radioactive waste is loaded onto a vehicle, the vehicle should remainunder close supervision to prevent unlawful tampering with the contents. It is not advisableto leave a vehicle unattended and out of sight of the driver whilst radioactive wastes arebeing carried, even though the vehicle is securely locked.

5.3. REQUIREMENTS FOR REFRIGERATED TRANSPORT

Unconditioned biological radioactive wastes must remain frozen, both prior to and duringtransportation. These wastes should be transported or transferred in special refrigeratedvehicles. Frozen animal carcasses can be transferred to a central receiving location readyto be loaded onto a vehicle that is either refrigerated or equipped with cabinets containingsolid carbon dioxide (dry ice).

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The refrigeration temperature during transport should be controlled, and the vehicleshould be fitted with a warning device in the event of failure of the freezer. There shouldbe documented contingency arrangements to be followed in the event of failure of the freezerwhilst transporting biological radioactive wastes.

5.4. DOCUMENTATION/RECORD KEEPING

Documentation accompanying radioactive materials to be transferred on- and off-siteshould contain sufficient information for its recipient to handle the wastes safely and inaccordance with requirements of any applicable regulations. As a minimum, the activity,isotope composition, chemical composition, volume, weight, dangerous properties oftransported material, date of transport and responsible person should be recorded. Theregulatory authority may require copies of all transfer documents, or require that they beavailable from the shipper and/or receiver for inspection.

6. QUALITY ASSURANCE

6.1. GENERAL

Quality assurance is an essential aspect of good management for biological radioactivewastes. Quality assurance includes all planned and systematic actions necessary to provideadequate confidence that an item, process or service will satisfy given requirements forquality. Quality assurance thus provides confidence that the objectives of waste managementare being met, as detailed in the appropriate specifications for waste processing, packagingand storage operations [31].

Intrinsic and desired properties that need to be quantified, monitored or otherwise assuredhave to be assessed for each management step. For handling, transport and storageoperations, the requirements mainly concern safety or operators, security of the wastes frominterference or theft and the behaviour of the packaging under possible abnormal conditions.

Quality assurance objective in waste management involves three components:

(a) the intrinsic quality of the process;

(b) rigorous implementation of process requirements to guarantee optimum quality of theproduct;

(c) control of the end product or end situation so as to assure conformity between thequality and composition of the end product, including the non-radioactivecomponents, and the agreed standards and criteria.

Quality assurance in the management of low level radioactive waste from hospitals andinstitutions should therefore be inherent in the design of the overall management strategy, inthe controls placed on each step in the execution of that strategy, and in the system fordocumenting this performance. Quality assurance should not rely on exhaustively checkingthe conditioned product [20].

It is clear that quality assurance programmes and audits will be different for centralizedand decentralized strategies. Greater incentives for comprehensive programme may be

44

associated with a centralized strategy, but it is essential that appropriate quality assurance isapplied in a decentralized system where maintaining standards may be more difficult becauseof the variety of activities and limited resources.

The IAEA recognizes that guidance on the quality assurance for radioactive waste shouldbe given to the competent national authorities as well as to individuals and organizationsdirectly involved in managing the waste. However, the basic responsibility for achievingquality in performing a particular task rests with those assigned that task, not with thoseseeking to ensure by means of regulation, that it has been achieved.

6.2. QUALITY ASSURANCE PROGRAMME

A quality assurance programme should be developed by the licensee/operator to defineand describe the relevant quality assurance steps and describe the interface arrangements withthe various groups or organizations involved in the waste handling, treatment and storage.Biological hazards as well as radiological hazards must be considered. It also should providefor production of documentary evidence to demonstrate that the required quality of processesand products has been achieved.

For waste management operations the following topics should be covered with a qualityprogramme:

(a) Purpose and scope (including a statement of committment from top management);(b) Organization (including identification and control of interfaces);(c) Personnel training and qualification;(d) Document control;(e) Design control (including plant modifications);(f) Procurement control (i.e. waste containers and any materials used in the waste

conditioning process itself);(g) Material control;(h) Initial qualification of the plant, the process and the waste package;(i) Product quality verification;(j) Records;(k) Assessment and audit;(1) Management review.

In the case of prédisposai waste management it should focus on:

(a) The minimization and segregation concepts for the waste arisings;(b) Accurate and complete documentation of the waste at the points of generation;(c) Waste acceptance criteria of the treatment facility;(d) Conditioning manuals containing details about materials; waste forms to be produced;

conditioning techniques and plants; testing and documentation;(e) Quality manuals for the production of waste packages;(f) A description of the control and measuring methods;(g) A documentation system which covers the required records; and(h) An organization which ensures the implementation of the QA programme.

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6.3. RECORD KEEPING

The preparation and maintenance of a comprehensive system for record keeping isessential. The need for recording specific information regarding the waste arising, and itssubsequent handling, treatment, and storage as well as the labelling of individual wastepackages has been described previously, (see Sections 4.1.3 and 4.4.2). In addition it islikely that there will be local regulations governing the records that are required to be kept.Records should be clear, legible, permanent and maintained up to date at all times, such thatthey are readily available for inspection. It is suggested that the record keeping system becomputerized. Multiple copies of the records or access to the database by several agenciesmay be required.

The documentation system should provide an integrated record of the waste from the timeof its production, through all of its handling and treatment stages, through to storage andfinal disposal. The system should be able to identify and track any individual package. Arecord of the final disposition of the waste must be maintained for an indefinite period,depending especially on the quantity and type of nuclides involved, and regulatoryrequirements.

Access to the record system or database must be allowed only to authorized individuals,and the system must be designed to resist tampering or alteration. The system shouldprovide appropriate back-up or redundancy to assure the data will not be lost due tounexpected accidents or events.

6.4. AUDITS

The implementation and effectiveness of the quality assurance programme should beverified through the auditing process. In general it is appropriate to relegate audits into threecategories;

(a) System audits;(b) Process audits;(c) Product audits.

System audits should (1) verify that programme and plans address the applicablerequirements, (2) verify that the programme and plan(s) requirements are adequatelyaddressed in implementing procedures, and (3) verify that implementation is adequate.

Process audits are necessary to verify that the processes are being operated withinspecified boundaries which were fixed in the course of process qualification and thathardware is being controlled in a manner that meets design requirements.

Product auditing usually involves the direct examination of waste form, the wastecontainer or the waste package. It should be performed when the auditing organizationpossesses the testing technology or expertise and the waste processor does not. Productauditing should also be performed when the waste processor samples, tests, or examines hisproduct on an ongoing or statistical basis.

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REFERENCES

[I] BAEHR, W., The IAEA's Programme of Technical Assistance for the Management ofRadioactive Wastes in Developing Countries, IAEA Interregional Training Course onManagement of Radioactive Wastes, 1987, Kernforschungszentrum Karlsruhe (1987).

[2] INTERNATIONAL ATOMIC ENERGY AGENCY, Standardization of RadioactiveWaste Categories, Technical Reports Series No. 101, IAEA, Vienna (1970).

[3] INTERNATIONAL ATOMIC ENERGY AGENCY, Guidance on Radioactive WasteManagement Legislation for Application to Users of Radioactive Materials in Medicine,Research and Industry, IAEA-TECDOC-644, Vienna (1992).

[4] INTERNATIONAL ATOMIC ENERGY AGENCY, Review of Available Options forLow Level Radioactive Waste Disposal, IAEA-TECDOC-661, Vienna (1992).

[5] INTERNATIONAL ATOMIC ENERGY AGENCY, Acceptance Criteria for Disposalof Radioactive Wastes in Shallow Ground and Rock Cavities, Safety Series No. 71,IAEA, Vienna (1985).

[6] WORLD HEALTH ORGANIZATION, Manual on Radiation Protection in Hospitalsand General Practice, Vol. 1, Basic Protection Requirements, WHO, Geneva (1974).

[7] INTERNATIONAL ATOMIC ENERGY AGENCY, Exemption of Radiation Sourcesand Practices from Regulatory Control, Interim Report, IAEA-TECDOC-401, Vienna(1987).

[8] BERGMAN, C., HELLSTROM, G., NORRBY, S., Establishment and Implementationof Exemption Levels in Sweden, Proc. Workshop on Rules for Exemption fromRegulatory Control, NUREG/CP-0101 (1988).

[9] ELECTRIC POWER RESEARCH INSTITUTE, Below Regulatory Concern OwnersGroup: Evaluation of Dry Active Waste Monitoring Instruments and Techniques, EPRI-NP-582, Final Report (March 1989).

[10] INTERNATIONAL ATOMIC ENERGY AGENCY, Principles for the Exemption ofRadiation Sources and Practices from Regulatory Control, Safety Series No. 89, IAEA,Vienna (1988).

[II] INTERNATIONAL ATOMIC ENERGY AGENCY, Management of RadioactiveWastes Produced by Users of Radioactive Materials, Safety Series No. 70, IAEA,Vienna (ir35).

[12] INTERNATIONAL ATOMIC ENERGY AGENCY, Minimization and Segregation ofRadioactive Wastes, IAEA-TECDOC-652, IAEA, Vienna (1992).

[13] INTERNATIONAL ATOMIC ENERGY AGENCY, Techniques and Practices for Pre-treatment of Low and Intermediate Level Solid and Liquid Radioactive Wastes,Technical Reports Series No. 272, IAEA, Vienna (1987).

[14] INTERNATIONAL ATOMIC ENERGY AGENCY, Handling and Treatment ofRadioactive Aqueous Wastes, IAEA-TECDOC-654, Vienna (1992).

[15] INTERNATIONAL ATOMIC ENERGY AGENCY, Containers for Packaging of SolidLow and Intermediate Level Radioactive Wastes, Technical Reports Series No. 355,IAEA, Vienna (1993).

[16] INTERNATIONAL ATOMIC ENERGY AGENCY, Storage of Radioactive Wastes,IAEA-TECDOC-653, Vienna (1992).

[17] INTERNATIONAL ATOMIC ENERGY AGENCY, Treatment of Low- andIntermediate-level Radioactive Wastes, Technical Reports Series No. 223, IAEA,Vienna (1983).

[18] INTERNATIONAL ATOMIC ENERGY AGENCY, Conditioning of Low- andIntermediate-level Radioactive Wastes, Technical Reports Series No. 222, IAEA,Vienna (1983).

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[19] INTERNATIONAL ATOMIC ENERGY AGENCY, Treatment and Conditioning ofRadioactive Organic Liquids, IAEA-TECDOC-656, Vienna (1992).

[20] INTERNATIONAL ATOMIC ENERGY AGENCY, Treatment and Conditioning ofRadioactive Solid Wastes, IAEA-TECDOC-655, Vienna (1992).

[21] INTERNATIONAL ATOMIC ENERGY AGENCY, Improved Cement Solidificationof Low and Intermediate Level Radioactive Wastes, Technical Reports Series No. 350,IAEA, Vienna (1993).

[22] INTERNATIONAL ATOMIC ENERGY AGENCY, Chemical Precipitation Processesfor the Treatment of Aqueous Radioactive Waste, Technical Reports Series No. 337,IAEA, Vienna (1992).

[23] INTERNATIONAL ATOMIC ENERGY AGENCY, Reference Design for a CentralizedWaste Processing and Storage Facility, IAEA-TECDOC-776, Vienna (1994).

[24] BUSH, D., HUNDAL, R.S., The fate of radioactive materials burnt in an institutionalincinerator, Health Physics 24 (1973) 564-568.

[25] CLASSIC K., GROSS G., VETTER R.J., Solubility of radionuclides in ash from theincineration of animals, Health Physics 49 (1985) 1270-1271.

[26] INTERNATIONAL ATOMIC ENERGY AGENCY, The Management of RadioactiveWastes Produced by Radioisotope Users, Safety Series No. 12, IAEA, Vienna (1965).

[27] INTERNATIONAL ATOMIC ENERGY AGENCY, Treatment and Conditioning ofSpent Ion Exchange Resins from Research Reactors, Precipitation Sludges and OtherRadioactive Concentrates, IAEA-TECDOC-689, Vienna (1993).

[28] INTERNATIONAL ATOMIC ENERGY AGENCY, Design and Operation of Off-gasCleaning and Ventilation Systems in Facilities Handling Low and Intermediate LevelRadioactive Material, Technical Reports Series No. 292, Vienna (1988).

[29] INTERNATIONAL ATOMIC ENERGY AGENCY, Evaluation of Low andIntermediate Level Radioactive Solidified Waste Forms and Packages, IAEA-TECDOC-568, Vienna (1990).

[30] INTERNATIONAL ATOMIC ENERGY AGENCY, Regulations for the Safe Transportof Radioactive Material: 1985 Edition (As Amended 1990), Safety Series No. 6, IAEA,Vienna (1990).

[31] INTERNATIONAL ATOMIC ENERGY AGENCY, Quality Assurance Requirementsand Methods for Low and Intermediate Level Waste Package Acceptability, TechnicalReports Series, IAEA, Vienna (in preparation).

r><MmO

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Documents

Handling, treatment, conditioning and storage of