REPÚBLICA ARGENTINA COMISIÓN NACIONAL DE ENERGÍA …rmb.ipen.br/DOC_RMB/DOC_REFERENCIA/OUTROS/Mo_99/Argentina.pdfREPÚBLICA ARGENTINA COMISIÓN NACIONAL DE ENERGÍA ATÓMICA. Lic

REPÚBLICA ARGENTINACOMISIÓN NACIONAL DE ENERGÍA ATÓMICA

Lic. Pablo CristiniFission Mo-99 Production

Buenos Aires, Argentina17 - 20 May 2005

Potential Mo-99 Producer´s Workshop

COMMERCIAL PRODUCTION OF FISSION Mo-99FROM LEU TARGETS

IN ARGENTINA

LIC. PABLO CRISTINIHEAD OF DIVISION FISSION Mo-99





The past

1977 α, β, γ hot cells construction

1978 Fission Mo-99 radiochemical process first experiences

1980 Target development

1985 First commercial production

1985 Enlargement of the building

1995 New hot cells

1999 Start Al x- U and U metal foil test targets

2002 Change from HEU to LEU





FISSION Mo-99 PRODUCTION

CNEA RECEIVED, WITHIN THE FRAME OF GERMAN-ARGENTINE AGREEMENT, THE TECHNOLOGY DEVELOPED BY DR. SAMEH AT KfK (KARLSRUHE) FOR PRODUCTION OF FISSION Mo-99 PROCESSING HEU TARGETS.





FISSION Mo-99 PRODUCTION

1985 – BEGINNING OF ROUTINARY PRODUCTION OF

FISSION Mo-99, PARTIALLY COVERING THE

LOCAL DEMAND





CONVERSION OF RA-3 CORE TO LEU FUEL

AS PART OF NON-PROLIFERATION POLICY OF ARGENTINA, DURING 1988-1989 , RA-3 CORE WAS CONVERTED TO LEU FUEL

POWER : 10 MWatt

NEUTRON FLUX: 1-2 x 1014 n/cm2.seg





CONVERSION OF TARGETS FOR Mo-99 PRODUCTION

HEU TARGETS MANUFACTURED BY CNEA:

U/Al ALLOY “MEAT”, WITH Al CLADDING

FOR CONVERSION TO LEU, THE FIRST STEP WAS TO TEST URANIUM SILICIDE TARGETS






LEU URANIUM SILICIDE PLATES PRESENTED A SUITABLE U DENSITY TO KEEP LEU TARGET GEOMETRY

THEY WERE TESTED IN BOTH, ALKALINE AND ACID DIGESTION






AS A RESULT OF THESE TESTS, IMPORTANT CHANGES WERE TO BE PERFORMED IN THE METHOD TO OBTAIN Mo-99 WITH ACCEPTABLE YIELDING AND QUALITY

NEXT ALTERNATIVE WAS URANIUM ALUMINIDE, TESTED IN ALKALINE DIGESTION






AFTER SEVERAL CHANGES IN THE FABRICATION PROCESS OF THE PLATES, A SUITABLE TARGET WAS ACHIEVED.

PROCESSING OF THESE TARGETS, REQUIRED ALSO MODIFICATIONS IN THE METHOD, THAT LED TO PRESENT PRODUCTION PROCESS, PERFORMED SUCCESSFULLY SINCE OCTOBER 2002, WITH GOOD YIELDING AND EXCELLENT QUALITY FOR ITS APPLICATION IN NUCLEAR MEDICINE





Mo-99 LEU TARGET





Mo-99 RADIOCHEMICAL PROCESS FEATURES

ALKALINE DIGESTION

FILTRATION

ION EXCHANGE PURIFICATION





ALKALINE DIGESTION

HOT CONCENTRATED NaOH SOLUTION

SOLUTION : Mo-99, I-131, Cs-137 and other F.P.

soluble in alkaline medium

PRECIPITATE: UO2 and insoluble F.P.

(actinides,etc.)





Mo-99 PURIFICATION

ANION EXCHANGE RESIN

CHELATING RESIN

ALUMINA COLUMN





Mo-99 PRODUCTION WASTE

GASEOUS STREAM

Storage of gases generated during digestion of

targets for 5 weeks before releasing them to hot

cells ventilation system






LIQUID STREAMS

. Medium Level Waste

Treatment for retention of Cs-137

Storage for at least 1 year before sending to

Waste Management Group for interim

storage and final disposal.






LIQUID STREAMS

. Low Level Waste

Storage for at least 6 months before

sending to Waste Management Group for

interim storage and final disposal.






SOLID WASTE

Storage for at least 6 months before

sending to Waste Management Group for

segregation and final disposition.

URANIUM CYCLE

U SUPPLY AND TRANSFORMATION

TARGET FABRICATION

IRRADIATION

TRANSPORTATION

RADIOCHEMICAL PROCESS

WASTE TREATMENT AND DISPOSAL

QUALITY CONTROLMo-99

IRR

AD

IAT

ION

TARGET FABRICATION

WASTE

U





Mo-99 HOT CELLS





TYPICAL QUALITY CONTROL VALUES FOR Mo-99 FROM LEU PRODUCED IN ARGENTINA

Limit valuesI- 131/Mo-99 1.50 x 10-7 5 x 10-5

Ru-103/Mo-99 1.67 x 10-8 5 x 10-5

Sb-125/Mo-99 5.88 x 10-10

Cs-137/Mo-99 3.62 x 10-10

Total β/Mo-99 7.88 x 10-10 1 x 10-8

Total α/Mo-99 1.21 x 10-11 1 x 10-9





TYPICAL QUALITY CONTROL VALUES

SPECIFIC ACTIVITY : > 5000 Ci/g Mo-99

RADIOCHEMICAL PURITY : > 95% AS 99MoO42-





Mo-99 PRODUCTION AND SUPPLY PROCESS

PROCESSING OF TARGETS






TARGETS

. Plates: UAlX / Al dispersion with Al cladding

. U / Al alloy rods

. Electrodeposited UO2 film

. UO2 pellets

. U metal foil

FISSION Mo-99 PRODUCTION METHODSsolid target

D i s s o l u t i o n

A c i d B a s i c

Enrichment

High

UO2 film on internal SS tube(Cintichem process)U/Al pins – extruded Al plates(Nordion process)

Alx-U / Al dispersion – Al clad plates(IRE process)(NPT process)(Mallinckrodt process)

Low

UO2 pellets(ANSTO process)

Alx-U / Al dispersion – Al clad plates(CNEA process)





PROCESSING OF TARGETS

. Acid dissolution

. Alkaline digestion





ACID DISSOLUTION

Dissolution with nitric acid (sulphuric acid)

U / Al, UO2 and U metal targets





ACID DISSOLUTION

First separation stage

.Aluminum oxide column

. Precipitation (α- benzoin oxime)





ACID DISSOLUTION FEATURES

. Noble fission gases and iodine released during dissolution

. NOx production

. Separation of Mo-99 from U needed






. Iodine retention system

. NOx conversion or trapping






Once Mo-99 separation is achieved, purification can be performed by several methods, also suitable for purification in alkaline digestion based processes





ALKALINE DIGESTION

Digestion with sodium hydroxide solution

U / Al, targets

U metal foil (under development)





ALKALINE DIGESTION

First separation stage

. Filtration and ion exchange

. Filtration and acidification





ALKALINE DIGESTION FEATURES

. Noble fission gases released while iodine remains in the alkaline solution

. H2 production

. Separation of Mo-99 from U, actinides and some F.P. is performed during digestion and filtration





Mo-99 PURIFICATION

. ION EXCHANGE

Anion exchange resins

Chelating resins

Inorganic exchangers (Alumina, SnO2)





Mo-99 PURIFICATION

. SOLVENT EXTRACTION

. PRECIPITATION (α – benzoin oxime)

. ACTIVATED CHARCOAL

. SUBLIMATION





Mo-99 PRODUCTION AND SUPPLY PROCESS

WASTE MANAGEMENT






Radioactive waste management is a main issue in fission Mo-99 production.

It must be carried out meeting internationally accepted safety criteria and national regulations.

Determination of costs involved in waste management is essential.





Waste-related aspects to be considered:

. Handling

. Treatment

. Conditioning

. Storage

. Transport

. Disposal





GASEOUS WASTE

ACID DISSOLUTION

. Fission noble gases and iodine + inactive Nox

ALKALINE DIGESTION

. Fission noble gases + hydrogen





TREATMENT OF GASEOUS WASTE

ACID DISSOLUTION

. Retention of inactive NOx

ALKALINE DIGESTION

. Conversion of hydrogen to H2O






IODINE (Acid dissolution)

Separation of iodine for commercial purposes from gaseous stream with suitable trapping system or storage for decay before releasing to ventilation system.






FISSION NOBLE GASES (Both)

Separation of Xenon for commercial purposes or storage for decay for 4 - 5 weeks before releasing the stream to ventilation system.





VENTILATION SYSTEM

Environment inside the hot cells has to be kept in underpressure and ventilated by means of fans or vacuum pumps.Outgoing air stream must pass through charcoal and absolute filters.













SOLID WASTE

Resin columns

Small replacement parts (hoses, QC, flasks), cotton, paper towels, plastic, glass, etc.

Eventually, damaged production equipment (dissolver, vessels, manipulator bootings)





SOLID WASTE

System for air-tight transferences from inside the hot-cell to transport or storage container.

















LIQUID WASTE

DISSOLUTION AND SEPARATION WASTE

.Intermediate level (ILW) or high level (HLW)

Mo-99 PURIFICATION WASTE

.Low level (LLW)





LIQUID WASTE

DISSOLUTION AND SEPARATION WASTE

Storage for decayment (at least one year)

Transference for transportation to treatment plant

Treatment for long term storage and/or final disposal (cementation, bituminization)





LIQUID WASTE

Mo-99 PURIFICATION WASTE

Storage for decayment (at least 1/2 year)

Transference for transportation to treatment plant

Treatment for long term storage and/or final disposal (cementation, bituminization)





LIQUID WASTE

CHARACTERIZATION

. pH

. Chemical composition (saline concentration)

. Radioisotopes content





COMMENTS AND RECOMMENDATIONS

. Formulation of criteria for waste disposal

. Capacity to fullfil these criteria

. Recording of waste data (volume, composition, date of generation)





COMMENTS AND RECOMMENDATIONS

. Segregation: important to reduce radiation doses, risk of incidents and management cost.

. Uranium segregation for recycling and to cover safeguard requirements

. Cost of waste management can have an important influence in Mo-99 final price.

Documents

REPÚBLICA ARGENTINA COMISIÓN NACIONAL DE ENERGÍA …rmb.ipen.br/DOC_RMB/DOC_REFERENCIA/OUTROS/Mo_99/Argentina.pdfREPÚBLICA ARGENTINA COMISIÓN NACIONAL DE ENERGÍA ATÓMICA. Lic