EXPERIENCES OF HEU TO LEU MO-99 PRODUCTION CONVERSION

Transcription

1 EXPERIENCES OF HEU TO LEU MO-99 PRODUCTION CONVERSION Budi Briyatmoko, 1) Boybul, 1) Sriyono, 2) A.H. Gunawan, 2) H. Lubis, 2) A. Mutalib, 2) Abidin, 2) Hambali, 2) 1) Center for Nuclear Fuel Technology BATAN, Serpong 2) Center for Radioisotope and Radiopharmaceutical BATAN, Serpong.

2 Introduction The HEU conversion to LEU to support the RERTR program The production Mo-99 is carried out by PT BATAN Teknologi by using HEU The HEU purchase experienced difficulty HEU stock is estimated finished in November 2010 Since 15 years, BATAN-ANL co-operated for the production Mo-99 from LEU target Since the last 4 years PTBN-BATAN gathered in CRP - IAEA developed LEU target PPR co-operated with PTBN and PT BATAN Teknologi developed the production Mo-99 from LEU target LEU foil target fabrication will be presented briefly Will be presented the result of Mo-99 production from LEU foil targets irradiated in 2009 as many as 4 times irradiation.

3 LEU Foil target fabrication MATERIAL Ingot LEU LEU Dimension: plate 50 x 50 x 3 mm PREPARATION FOR HOT ROLLING Frame and cover from carbon steel (CS) were used to make composite of LEU plate. Frame Dimension: 50,1 x 50,1 x 3,1 mm Cover Dimensi: 100 x 100 x 3 mm (2 pcs) Plate of LEU ingot was put in the frame and cover of CS plates which were coated by paste, mixed of 50 % dextrine (C 6 H 10 O 5 )n. x H 2 O and 50 % alcohol. LEU in the frame and cover was welded by SMAW using Cu chill block to protect heat conduction from weld to LEU plate.

4 Ingot LEU, frame and cover of Carbon Steel Welding process of assembly Assembly of cover, frame, ingot LEU and cover; ready for welding Welding result

5 After welding, the assembly was wrapped in SS foil envelope and sealed to protect oxidation during annealing. Before hot rolling, assembly was heat treated at 625 C for 1 hr in argon environment. Assembly in SS envelope Furnace for annealing

6 HOT ROLLING Hot rolling was conducted gradually reduce the thickness of sample Assembly was come out from furnace and it will be rolled Assembly going into the roll.

7 Thickness measurement. Assembly condition after hot rolling Assembly cutting to take out the foil Foil dimension measurement after hot rolling

8 COLD ROLLING Clean the foil with perchloretylene (C2H4Cl4) during 5 minutes to remove dextrin. Pickling was done use 50 % HNO3 and 50 % water, for 7 minutes; then cleaned with water for 3 minutes and with alcohol for 1 minute Stainless steel plate has been used to cover the foil during cold rolling Cleaning and pickling process Foil after pickling Cold rolling Foil resulted from cold rolling

9 HEAT TREATMENT AND QUENCHING Use SS foil envelope to protect the foil from oxidation during heat treatment and quenching LEU Foil inserted in the SS foil envelope, vacuumed and sealed (by folding the envelope 4 times) for heat treatment and quenching. Heat treatment temperature is 720 C for 20 minutes, and quenching in water for 15 minutes. LEU foil wrapped by SS foil and oxygen evacuation with rotary pump Heat treatment and quenching

10 FOIL ASSEMBLING Before assembling, the foil has been wrapped with mm nickel foil Aluminum tube has been cleaned and bright dip in mixed acid solution LEU foil will be wrapped with Ni foil. Aluminum tube in bright dip

11 Dimension of aluminum tube for target is: Outer tube: ID mm, OD 30 mm Inner tube: ID mm, OD mm Drying of tubes after bright dip Cleaned tube after bright dip. Assemble the foil into the tubes Marking the outer tube

12 Assembled draw die with target Machining the end of the tubes Target welding Welded target

13 Resizing of target in slip-roller Target inserted in outside diameter gauge

14 LEU foil target irradiation LEU target was irradiated in CIP PRSG-GAS Irradiation time 4 days Reactor power 15 MW Post irradiation, LEU target was sent to radioisotope hot cell through the transfer channel

15 LEU foil target disassembly Disassembly in radioisotope hotcell Using cutting machine

16 LEU foil dissolution LEU foil was put into dissolver and closed the dissolver Injected 40 ml HNO3 solution through rubber septum available in T-section used 60 ml syringe Heated 93 C for 30 minutes while being turned with the rotator jig Monitor the pressure

17 Iodine gas and noble gas separation The dissolver joined iodine trap and cold finger that has been vacuum Cold finger immersed in a Dewar containing liquid nitrogen open the valve between the cold finger and T-section for 30 minutes closed the valves and released the connection Remove the solution from the fission of U-235 from dissolver and placed in a 250 ml double-ended bottle coated with plastic and marked by RF Dissolver purged with 25 ml HNO3 1 M and rinsing solution inserted in the bottle RF

18 Mo-99 precipitation Existing Mo-99 in the bottle RF is precipitated by adding 4 ml carrier solution of NaI (1mg NaI/ml) 0.5 ml solution of AgNO3 10% 0.5 ml carrier solution of Mo (10mg Mo/ml) ±25 ml solution of KMnO4 25% gradually changed to pink color 1.5 ml carrier solution of Rhodium (8mg Rh/ml) 2 ml carrier solution of Rutenium (5mg Ru/ml) 20 ml solution of Alpha Benzoim Oxime 2% Vibrate and allowed one minute until Mo precipitate is formed

19 Filtration of precipitate Mo-99 Using fritted column 51 mm containing granulated fritted The filtrate was collected in a 25 ml bottle which is coated by plastic and marked RFW (fission product waste solution) Rinse bottle RF with 20 ml HNO3 0.1 M solution, conducted 3 times The first rinse is inserted in the bottle RFW Rinses for the second and third is inserted in the 250 ml bottle which is coated by plastic and marked by AW (acid waste) Mo containing Fritted column was washed with 10 ml of 0.1 M HNO3 performed five times with 10 ml syringe through the bottom of the fritted columns. The rinse is placed in a bottle AW.

20 Mo precipitate dissolution in fritted column Injected 10 ml solution of X-1 (mixture of 99.5 ml NaOH 0.4 M and 0.5 ml H2O2 30 %) Set a ventilation column heat until boiling chill for 5 minute Mo-99 solution is removed from the column was collected in plastic coated double-ended 250 ml bottles marked 1-A Repeated one more, injected 10 ml solution of X-2 (mixture of 99.5 ml NaOH 0.2 M and 0.5 ml H2O2 solution 30%) Mo-99 solution enter into the bottle 1-A Fritted column washed or flushed with 10 ml NaOH solution 0.2 M Resulted flushing solution put in the bottle 1-A

21 Mo-99 purification Purification of Mo-99 solution in bottle 1-A Enter the solution into fritted column containing resin HZO and AgC with gravity flow rate of about 1-3 ml / min The elution is collected into the 250 ml double ended bottle which is coated with plastic and marked 2-A Bottle 1-A rinsed with 10 ml of 0.2 M NaOH and loaded on fritted column Resulted elution is put in bottle 2-A

22 Mo-99 purification (cont d) Add the solution in the bottle 2-A with 4 ml solution of carrier NaI (NaI 1mg/ml) and 0.5 ml 10% AgNO3 solution Shake and allowed five minutes to precipitate the impurities of iodine fission products that can still be contained in a solution of Mo-99 Mo-99 solution in a bottle 2-A eluted through a fritted column containing resin AgC / HZO / Charcoal by gravity with a flow rate of about 1-3 ml / min The elution is collected in a 250 ml plastic coated bottle marked with Mo- 99 products, Batch No. and Date Bottle 2-A rinsed with 10 ml 0.2 M NaOH solution Eluted again through the same column The resulted elution is accommodated in the bottled product Mo-99 Total volume of Mo-99 solution products generated approximately 55 ml

23 Mo-99 radioactivity measurements and purity Measure the concentration of radioactivity of Mo-99 solution of 100 μl of sample products with Gamma Ionization Chamber Sample was counted with a spectrometer γ to determine the purity of radionuclide The sample is also measured by the α - β counter to determine the content of α- impurities in a solution of Mo-99

24 HEU TARGET Chemical composition, UO2 Enrichment U-235, ± 93 % Pipe material, single pipe SS 304 Length & Diameter, 457 mm & 29 mm Method, electroplatting Total weight U-235 per target, 3 g

25 LEU TARGET Chemical composition, U metal Enrichment U-235, ± % Pipe material, double pipe Al Inner pipe: 162 mm length, 28 mm diameter Outer pipe: 162 mm length,30 mm diameter Method, hot roll & cold roll Total weight U-235 per target, 1.5 g & 3 g

26 Irradiation HEU target capsule is inserted directly into the stringer upright position, while the LEU target capsule using target rig (Al) entered into a stringer HEU irradiation capsule only in the singular, whereas LEU can be made tandem Same position, irradiated in CIP with neutron flux of 1.02E14 n Cm -2 s -1 Irradiation time 4 5 x 24 h

27 Irradiation position HEU and LEU target Rig HEU target LEU target LEU foil

28 Handling of irradiated target for HEU targets, simply open the cover of capsule and replaced with a series of T-section The next process of the dissolution of uranium embedded in the inner wall of the target capsule by injecting 86 ml of "cocktail" (a mixture of 95 ml 2N H2SO4 HNO3 with 5% 65 ml) While handling for LEU target, the process of dismantling should be done before target foil dissolution process

29 LEU foil target disassembling cutting the two ends of the LEU target with a pipe cutter Cutting longitudinally across an outside tube of the target Disassembly LEU foil from inside of the tube target LEU foil put into dissolver and covered with a lid equipped with a series of T-section Dissolution of the foil target by injecting 40 ml 6M HNO3 to 1.5 grams 235U target or 9M HNO3 to 3.0 grams 235U target

30 Dissolver and T-section T-section Dissolver cover With T-section HEU Capsule Dissolver

31 Chemical separation process gas phase chemical processes and separation process also purification process of radionuclide 99Mo of HEU and LEU targets material exactly the same only during the washing of precipitation Mo using 0.1 N H2SO4 solution at HEU replaced with 0.1 M HNO3 solution at LEU

32 Product analysis of Mo-99 from LEU ANALYSIS Weight 235U, (g) 1,5 Specific activity, (Ci/g Mo) Radioactivity concent., (mci/ml) Radionuclide purity, (µci/mci 99 Mo) α-contamination *, (µci/mci 99 Mo) * (Detektor ZNS, β counter) (April 2009) foil target 3,0 (June 2009) RESULT 3,0 (Agust. 2009) 3,0 (Okt. 2009) 1.02 x x x x I : Ru : nd 89Sr : nd 90Sr : nd γ-impurities: I : Ru : nd 89Sr : nd 90Sr : nd γ-impurities: I : Ru : Sr : nd 90Sr : nd γ-impurities: I : Ru : Sr : nd 90Sr : nd γ-impurities: x x x x 10-8

33 99Mo specification from Medy Physic use HEU target Analysis MEDY PHYSIC SPECIFICATIONS Specific activity, (Ci 99 Mo/g Mo) > 1.0 x 10 4 Radioactivity concentration, (mci 99Mo/ml) > 100 Radionuclide purity 131I < 0.05 µci/mci 99Mo 103Ru < 0.05 µci/mci 99Mo 89Sr < 0.6 nci/mci 99Mo 90Sr < 0.06 nci/mci 99Mo γ-impurities < 0.1 µci/mci 99 Mo Alpha contamination, (µci alpha/mci 99Mo) < 1.0 x 10-6

34 Conclusion LEU foil target fabrication technology is ready for commercial production From the results of development of material production of 99Mo from fission 235U targets using low-enrichment uranium (LEU) can be concluded: Four times LEU foil targets irradiated 99Mo products meet the requirements for radionuclide purity (Medy physical) that can be used for the manufacture of raw materials 99Mo/99mTc generator. radionuclide impurities γ transmitters and α transmitter meet the criteria established by Medy Physics Separation process and the cost of handling radioactive waste is cheaper because it does not use sulfuric acid in the separation process