Experiences in Recycling &

Reuse of Radioactive Sources in

BRIT AK Kohli

Chief Executive

Board of Radiation & Isotope Technology

Department of Atomic Energy

Department of Atomic Energy • Bhabha Atomic Research Centre

• Nuclear Power Corporation

• Uranium Corp of India Ltd

• Nuclear Fuel Complex

• Indian Rare Earths Ltd.

• Atomic Minerals Directorate

• Heavy Water Board

• Indhira Gandhi Centre for Atomic Research

• Bhartiya Vidhyut Nigam

• Centre for Advanced Technology

• Variable Energy Cyclotron Centre

• Board of Radiation & Isotope Technology

Aided Institutions

• Tata Instt of Fundamental Research

• Institute of Physics

• Saha Institute of Nuclear Physics

• Harish Chandra Research Institute

• Institute for Plasma Research

• Tata Memorial Centre

• Institute of Mathematical Sciences

Major Activities of BRIT • Industrial Gamma Based Radiation Processing Plants

• Radiation Processing Services

• Laboratory Irradiators

• Radiography Exposure Devices

• Sealed Radiation Sources

• Open Radiation Sources

• Brachytherapy Applicators

• SPECT & PET Radiopharmaceuticals

• 99Mo-99mTc Generators

• Radioimmunoassay Kits

• Labelled Compounds

• Labelled Biomolecules

BRIT has a total clientele of about 2000

Management of Sealed Radiation Sources

• Nuclear Reactors

- NPCIL

- BARC

• Production & Testing of Sealed Sources

Transportation Flasks

- BRIT

• Disposal Facilities

- BARC

Co-60 Production in PHWRs

BRIT - Rawatbhatta

Source Fabrication

IFRT- New Facility for

Fabrication & Installation of Sealed Sources

Vashi, Navi Mumbai

• Hot Cell : 300 kCi of Co-60. • 4 Large Viewing Windows • Water Pool : 1MCi, Size 4m X 3m 6.2m deep • Radiometry room • 25/10 Te Capacity Crane • 3/1 Te capacity In cell Crane

Sealed Source Manufacture

• Design: Type approved by AERB based on

various tests

• Shape: Cylindrical

• Material: Austenitic Stainless Steel

• Encapsulation: Doubly encapsulated with

TIG welding on both inner & outer

• Testing - Leak Tightness

- Contamination

Major Equipment Incorporating

Sealed Radiation Sources

• Industrial Irradiators : Dry & Wet Storage – Co60

• Laboratory Irradiators : GC & BI- Co60

• Teletherapy Machines : Old – Cs137, New- Co60

• Radiography Exposure Devices : Ir192, Co60 , Tm 170

• Nucleonic Gauges : Cs137 , Co60

• Manual Afterloading Applicators : Cs137

• HDR Brachytherapy Equipment : Ir192

BRIT’s Transport Packages

• Excepted

• Type A – 12 nos.

• Type B(U) – 9 nos.

• Type B(M) – 2nos.

Type B(U) Test Facilities at ARAI, Pune

Sealed Sources are normally

employed for 1 to 3 half lives in

any particular application and

reused/recycled to the extent

possible

Co-60 Sealed Sources

Sp. Activity in Various Applications

• > 200 ci/gm: Teletherapy, Radiography

• 50-100 ci/gm: Irradiators, Nucleonic Gauges

• 20-50 ci/gm : GC-5000

• 10-20 ci/gm : GC-1200

• < 5 ci/gm : Blood Irradiators

Graded Sp. Activity in Co-60

• Reuse (as it is) after integrity evaluation

• Re-encapsulate & use in different a

application

• Recover & mix for use in appropriate

application

Facilitates use in 2 to 3 applications

( up to 40 yrs)

Reuse of Decayed 60 Co

Teletherapy & Irradiator Sources

- Without any modification

- Leak/Contamination Testing

- Incorporation into another bigger source

capsule

OUTER TUBE

(O.D 27.2xI.D.25.5)

DECAYED TELETHERAPY CTS-1

SOURCE CAPSULE (11 NOS)

ALUMINIUM SPACER

(Ø23x10 THK. 2 NOS)

43218 13

463

W-91-Th SOURCE PENCIL

MATL- S.S.316L

ALL DIMENSIONS ARE IN MM

Utilization of Decayed teletherapy sources

in Industrial Irradiators

DECAYED W-91 PENCIL

(DIA 27.2x463 Lg .)

W-91 MARK-I I

SOURCE PENCIL ASSEMBLY(DIA 30x470 Lg .)

DECAYED PENCIL WITH TOP CAP

AND SPIGOT CHOPPED OFF

4 1 2 3

OUTER ENCAPSULATION TUBE

DESCRIPTION PART

1

2

3

4 SPIGOT

TOP CAP

INNER ENCAPSULATION TUBE

5

5 COBALT-60

High Dose to Low Dose Irradiator

with another encapsulation

So far 300 decayed teletherapy

sources worth 400kci have been

incorporated in 26 W-91

irradiator source pencils in

irradiators and are in use

Recycling of Decayed 60 Co

Teletherapy Sources

• Sources cut open in the hot cell at the

weldments

• Radioactive Pellets recovered and re-

incorporated into a different source capsule

configuration

Ø 25x30L

3

1

24

TELE THERAPYCO-60 SOURCE CAPSULE

( I )

OUTER CAPSULEBEING CUT

( II )

INNER CAPSULEBEING CUT

( III )

CO-60 PALLET

( V )

Ø 1x1

GAMMA CHAMBER PENCIL

( VI )

Ø 11.5x130L

FABRICATION OF GAMMA CHAMBER PENCIL FROMDECAY TELE THERAPY SOURCE CAPSULE CO-60 PALLET

1. Inner Capsule2. Inner Cap

3. Outer Capsule4. Outer Cap

INNER CAPSULEAFTER CUTTING

( IV )

So far radioactive pellets from

70 decayed teletherapy sources

worth 100kci recovered and re-

incorporated into 100 GC

sources & are in use

Reuse & Recycling of Cs-137

Sources

• Very long half life (30 yr)

Used in :

• Now obsolete teletherapy equipment

( CsCl powder)

• Manual Afterloading Applicator

• Nucleonic Gauges

Recycling of Decayed Cs-137

Teletherapy Source • Pierce the source

• Dissolve in water & add HNO3

• Converts to CsNO3

• Evaporate

• Incorporate into glass forming mixture

• Melt & convert into active glass

• Cast into Pt cylinder

• Coat with Ag

• Encapsulate in SS capsule

One 200 ci Cs-137 teletherapy

source converted into 1200

f 1.5 mm x 5 mm long glass

rods for brachytherapy sources.

15 Manual After Loading

Applicator kits using 300 such

glass rods are in use

Reuse of Returned/Decayed Cs-137

Nucleonic Gauge Sources

• Reuse as it is after leak/contamination tests

• Incorporate no. of sources into a bigger

capsule for use

150 Cs-137 sources have been put to reuse.

2 sources each 20ci in teletherapy capsule

have been fabricated from 10 nos. each of

smaller sources of ~ 2ci and are in use.

Ir-192 Sealed Sources

• Radiography, HDR & LDR Brachytherapy

• Low half life (74 days)

• BRIT manufactures sources for all

indigenous & imported radiography

devices; Pt coated Ir wire & HDR

indigenous

• Hold, recover & reuse as a fresh material

BRIT Made Radiography Exposure

Devices

Ir-192 Sealed Sources

• ~ 22, 000 sources made so far

• No ultimate disposal

• Ir becomes available after ~7-10yrs for re-

irradiation, if reqd (once done) or disposal

as trash

Recycling of disused/decayed 192 Iridium sources

• Till 1994, 1 or 2 pellets of f 1.6 X 1.6 mm

ht & f 2 X 2 mm ht in a SS capsule of size

f 7.5 mm X 8.0 mm ht were used in IRC-

2,3 (total 8ci) & IRC-4 (total 20ci)

• After 1994, f 2.7x0.3mm thk discs only are

used

• < 5% of 191Ir is converted

• Pellets were recovered by machining in the

hot cell

• 300 pellets cooled for 7-10 years were taken

up for recycling in 1997.

• 5 std Al cans with 60 pellets each wrapped

in Al foil in a lead glass shielded fume hood

and were prepared for irradiation.

Activity and Dose Details for192 Ir Radiography sources

T1/2 for 192Ir=74.4 days

No of

years

Activity

Ci

Dose at

1 cm(R/hr)

Activity

Ci

Dose at

1 cm(R/hr) 0 8 40000 100 500000

1 0.26 1335 3.338 16690

2 0.009 44 0.11 557

3 0.0003 1.48 0.003 18.5

4 9.93E-06 0.049 0.00124 0.620

5 3.31E-07 0.001 4.14E-06 0.02

6 1.10E-08 5.5 E-05 1.38E-07 0.0006

7 3.64 E-10 1.81E-06 4.62E-09 2.31E-05

8 1.23E-11 6.17E-08 1.54E-10 7.71E-07

9 4.12E-13 2.06E-09 5.14E-12 2.57E-08

10 1.37E-14 6.87E-11 1.72E-13 8.59E-10

Dose rate on irradiation

can((mR/hr)

No of pellets re irradiated

Pellet details

Dia(mm) X Ht(mm

Irradiation period

MWD

Activity developed per

recovered pellet per

Ci

5 60 2.0 X 1.0 4268 9.75-11.2

10 60 1.6 X 1.6 4818 10.11-13.0

5 60 1.6 X 1.6 4715 10.11-15.17

20 60 2.0 X 2.0 5034 12.0-13.0

15 60 1.6 X 1.6 5365 10.0-13.0

Re-irradiation at Dhruva of decayed

radiography source pellets

Management of Leaky Sources

• Clean to the extent possible

• Encapsulate

• Store pending disposal

Cradle to Grave Philosophy is

followed • If impractical or economically not feasible to reuse or

recycle , the sources are kept in an interim storage pending final disposal.

• From the storage facility, dressing of sources is done, if required (cutting of cables or other bigger non-active parts)

• Encapsulation into SS Canister

• Loading into Transportation Flask

• Journey to Engineered Near Surface Disposal Facility

• Disposal

Engineered Near Surface Disposal Facilities

• Trombay

• Kalpakkam

Concluding Remarks • India follows the Code of Conduct on Safety & Security

of Sources

• AERB regulates and keeps the documentation of the

process right from source design, manufacture, equipment

design, customer authorization, site approval, transport &

disposal

• BRIT is the sole manufacturer of sealed sources in India

• Sources are manufactured as per international standards

• Sources are reused and recycled to the extent possible

• Expertise available for proper management of sources

including disposal

Thanks