The Rossendorf Experiences in Fission-based Mo-99 Production

Transcription

1 Gamma-Service Group International GmbH The Rossendorf Experiences in Fission-based Mo-99 Production Gerd J.Beyer based on work performed by RM R.Muenze, GB G.Beyer, D.Novotny, DN G.Wagner GW Consultancy Meeting on Conversion Planning for Mo-99 Prodcution Facilities from HEU to LEU Vienna, Austria August 2010 The reproduction, transmission or use of this document or its contents is not permitted without express written authority. Offenders will be liable for damages. All rights, including rights created by patent grant or registration of a utility model or design, are reserved.

2 SCOPE of CONTRIBUTION History: why Tc-99m? 1963: The first Rossendorf fission based Mo-99 production technology (Unat metal) 1981 AMOR 1 (36 w% U-5 fuel element as target) Mo-99 in TBq-region 1986: AMOR 2 (reprocessing of waste) 1990: AMOR 3 (preparation of new target fuel elements from recycled U) 1991: Reactor shutdown and new orientation of the team 2005: ROMOL-99 : the new Rossendorf Mo-99 process designed for LEU 2010: Concept: ROMOL-LITE LITE downscaled & simplified ROMOL-99 process for low performance RRs 2010: Concept: LITE-MOL small scale Mo-99 production for low performance RRs based on metallic U of no or very low enrichment

3 Why Tc-99m? From the bio-chemical or bio-medical point of view Tc is the most crazy element we can think off. Why than Tc-99m? 3 Aspects: Suitable single photon Generator principle Sn(II) as reducing agent

4 How it began the detection ti systems B.CASSEN 1951: 1958: SCANNER GAMMA CAMERA The scanner was designed for I-131 The camera is taylor- made for Tc-99m Pre-amplifier PM-tube Pb-shielding NaI-Detector Collimator Object Scan Thyroid normal The basic concept of the gamma camera remained without major changes and represents the basic principles for all SPECT instrumentation by today. H.O.ANGER

5 The Mo-99/Tc-99m Generator 1957 The Mo-99 / Tc-99m Generator: The Tc-99m Generator was developed at the Brookhaven National Laboratory. The Mo-99 activity in the form of molybdate ion (MoO42-) is bound to an alumina column. The Tc-99m activity, being chemically different as the pertechnetate ion (TcO4-) is not bound and eluted from the column with normal saline (0.9% NaCl). (irony: a patent request was rejected because of no practical use) Image tarken from Eckelmann W.C. JACC Imaging 2, (2009) The Rossendorf Tc-99m Generator developments p Pb shield Column 0.9% NaCl-bag Al2O3 Tripod Frame 1964 First European fission based Mo/Tc-99m generator insterile wet used until sterile wet generator Since 1982 ROTOP Sterile dry generator

6 Sn(II) as reducing agent The 60s: Being aware of the favorable nuclear properties p of Tc-99m radiochemists tried to bring the Tc-99m into a chemical form that allows to label organic compounds. The breakeven was reached with the introduction of Sn(II) in Historical overview on introduction of Sn(II) see: Eckelman WC, Richards P. Instant 99m-TcDTPA, J.Nucl.Med. 1970, 11, : Introduction of Sn(II) as reducing agent: Dreyer R. & Muenze R.; Markierung von Human Serum Albumin with 99m-Tc Wiss.Z.K-Marx Uni Leipzig Nat.Wiss.R. 18 (1969) Zur Tc-99m-Markierung von Serumalbumin; Isotopenpraxis 5 (1969) 296 The authors missed to make a patent! 2009: Eckerman W.C.: JACC Imaging 2, (2009) J On a practical level, the use of stannous ion was a key development and current radiopharmaceutical kits employ the stannous reduction technique. With the advent of the Mo-99/Tc-99m generator in the 1960s followed by the development of "instant" kits, the use of Tc-99m labeled compounds expanded rapidly The Rossendorf Tc-99m based Radiopharma- ROTOP Diphosphonate ROTOP MDP ROTOP EHIDA ROTOP HSA / B1 ROTOP DTPA ROTOP HSA / B20 ceuticals: ROTOP DMSA ROTOP MYOSCINT

7 1963 Fission based Mo-99 production The production of fission products including Mo-99 began in Rossendorf 1963: First fission-based Mo-99 production process worldwide Target: Flux density: nat U metal up to 180 g 80 pellets; 4.5 g each up to 7E+13 n/cm 2 sec storage vessel cooler Irradiation time: Cooling time: 100 h 48 h gas input filling funnel for target material Trap 4 (for Xe-adsorption) Solvent: 310 ml 10 M HCl 50 ml conc. HNO 3 Productivity: 105 Ci 99 Mo (EOB) 15 Ci 99 Mo (6 day) Process yield: ~70 % Byproducts: 133 Xe, 131 I, 132 Te/ 132 I Waste: solidification of the liquid waste included output of fission product solution Trap 1 dissolution vessel Trap 2 Quartz and glass apparatus In operation until 1980 Trap 3 charcoal dewar vessel

8 Target Design for nat-u metal U-pellet Al-spacer Mat.: AlMg1Si1 Irradiation Can Al-cooling tube Ø= 20 mm Al-target tube Ø= 12 mm Al-spacere nat. U-pellet 85x42mm Cooling jacket Target: U nat rods from Russia Ø = 8.5 mm Pellets (4.5g) of 4.2 mm height were cut by lathe machining at the Rossendorf workshop Al-tubes of Ø o 12 x 1 mm were filled with 6 U-pellets separated by 7 spacers of 10 mm thick Al The individual Al tubes were welded and He-leak tested. One standard irradiation insert carried 5 of those tubes. The irradiation inserts were stabilized with a lead plug. This target configuartion has been safely irradiated for 100 h at Ø = 7.5E13 n/cm 2 s

9 1981: AMOR-1 Process Rossendorf AMOR = Anlage zur 99 Mo-Produktion Rossendorf; became operational after 5 years of intense R&D Original fuel element of the RF-reactor: ~1 kg Al, ~105 g 36 w% 235 U, no target development needed! Dissolving i in 20 L HNO 3 / 1 mmol Hg(NO 3 ) 2, H 2, 133 Xe No precipitate, no filtration process Large volume of about 20 L, Mo-Separation Al 2 O 3 batch adsorption process, centrifuge Purification by a column process, oxidation (HNO 3) and sublimation Large volume of waste solution stored (under IAEA-control) Heavy INOX equipment Batch size ~1200 Ci Na 99 2 MoO 4 (end of process ~ EOI + 72 h) In operation until 1991 (ended due to decommissioning of the RFR) R.Muenze, O.Hladik, G.Bernhard, W.Boessert and R.Schwarzbach; Large scale Production of Fission 99 Mo using a Fuel Element of a Research Reactor as Starting Material, Int.J.Appl.Radiat.Isot. 35 (8), (1984)

10 1981: AMOR-1 Process Rossendorf

11 1981: AMOR-1 Process Rossendorf

12 1986: AMOR-2 Process Rossendorf AMOR-2: Recovery er of Uranium The waste solution from the AMOR-1 process was stored in an underground storage system consisting of very large waste collection tanks (each 2500 L). The waste solution was under continuous control of the IAEA (fuel balance control) After a cooling period of 5 years the fuel was extracted and purified using a modified PUREX-process with TBP / tetracloro-ethen. Initial U-concentration: initial activity concentration: ~2.6 g/l after extraction: < 10 mg/l ~0.3 Ci/l Re-extraction with 0.1 M HNO 3 10 gu/l After soldification the UO 2 (NO 3 ) 2 was used for fabricating new targets for the 99 Mo-production (AMOR-3) O.Hladik, G.Bernhard, W.Boessert, T.Grahnert and R.Muenze,; The Recovery of Uranium from the Waste Solution of Fission 99 Mo Production, Int.J.Appl.Radiat.Isot. 38 (8), , (1987)

13 1986: AMOR-2 Process Rossendorf IAEA-control AMOR waste solution after 5 years decay Mixer Settler battery TBP / Perchloro-ethenethen extraction Uranyl-Nitrate used for new target fabrication (AMOR-3)

14 1991: The New Orientation of the Team in the year of the German Re-unification the isotope production plant in Rossendorf had reached an internationally well recognized standard with well developed infrastructure, reliably functioning industrial scale Mo-99 production, regular Tc-generator production, well developed radio-pharmaceutical and KIT production guided by an internationally well-known expert team of scientists and engineers. However: The heart for all these activities, the Rossendorf RR has been shut down and was decommissioned afterwards. Consequently the basis for production and further R&D was lost. A major part of the expert team carrying long year practical experiences in designing, manufacturing and commissioning of related plants and equipment (engineering and scientific staff) became organized under new conditions of the socalled free market: at first within the Hans Waelischmiller GmbH (HWM), later known as Isotope Technologies Dresden GmbH (ITD) and finally as Gamma Service Group International GmbH (GSG), by today.

15 The ROMOL-99 Process 2003 HWM GmbH was asked to develop a Mo-99 production technology of industrial scale (~1TBq). The customer was the Pakistan Institute of Nuclear Technology (PINSTECH) The new process carries the registered trade name ROMOL-99. Requested binding parameters: Full autonomy Capacity ~100 Ci (6-days) Mo-99 UAl alloy target, Al-cladded Enrichment 20 w% 235 U (LEU) N-flux density up to 1.5 x n/cm 2 s Avoidance of H 2 -generation As much as possible FP in the precipitate Partial process automation

16 The Reaction Equation Solvent: 3 N NaOH / 4 N NaNO % : 8Al + 3 NaNO NaOH + 2H 2 O 8 NaAlO NH % : Al NaNO 3 + NaOH NaAlO NaNO H 2 O ~ 0 % : Al + NaOH + H 2 O NaAlO H 2 Master Equation: Al U + ( x) NaNO 3 + ( x) NaOH + + ( x) H 2 O NaAlO Na 2 U 2 O 7 + ( x) NH x NaNO < x < As expected: no H 2 formation ~ 85 % goes to NH 3 and ~15 % to NO - 2

17 Filter tower Irradiated U/Al targets Xe-133 decay Target and solid waste handling HC2 Xe trap Off-gas HL solid waste filter-cake (U-235) U+FP+TU Basic dissolution (3 M NaOH/4 M NaNO 3 ) Filtration Iodine column 1 Mo+FP (residues) Acidification (HNO 3 ) Feed solution handling and distribution Xe, Kr, Gas NH 3, H 2 O H-3 treatment NH 3 - absorption (H 2 SO 4 ) Xe (residues) Iodine (residues) HC5 Iodine column 2 HC1 and HC3 Liquid waste transfer Process scheme for industrial scale Mo-99 prodcution based on a hot cell system of 7 cells arranged in 3 separate blocks, enabling operation of two processes simultaneously Mo-99 separation (Al 2 O 3 column) Purification 1 (Dowex column) Evaporation Purification 2 (high temperature process) HC4 and HC6 Mo-99 dispensing Mo-99 (final product) HC7 The ROMOL-99 Process

18 The Process-Activity Partition Total activity at EOI+36 h ~10 kci (=100%) (depending on conditions) 12% 10% ~65 % ~13 % Iodine Gases Xe & Kr Filtrate FEED Solution: Mo + Tc, Group I 30 % of group VIIIB Filter cake Spent target fuel, TU FP of groups II, III, IV,V,VI Liquid Waste ~12 L/batch Liquid waste storage: up to 8 weeks below hot cell 3 months in decay tanks R4 finally waste treatment plant Solid waste: (Columns, hoses etc.) 99 Mo Ci (1-3 months), Intermediate storage in hot cell 2 then waste treatment plant

19 Process Equipment at PINSTECH

20 GSG-Touch-Screen Operation p System y Screen Shot During Dissolving The image cannot be display ed. Your computer may not hav e enough memory to open the image, or the image may hav e been corrupted. Restart y our computer, and then open the file again. If the red x still appears, y ou may hav e to delete the image and then insert it again. Temperature recording

21 ] ROMOL-99 - The Dissolving Process Tempe erature in [oc] Heating on Cooling on Temperature during dissolving process End of dissolving Time [min] oling jacket empty Co oling jacket empty Co Dissolving in a hermetically closed system with a cirulating gas flow Dissolving initiated by a short heating pulse Strong exotermic reaction controlled by short cooling periods End of dissolving indicated when temperature does no more grow Pressure during dissolving process well below atmospheric pressure 0 Pressure in the vessel during dissolving process -0.1 Pressure in [Bar] Time in [min] By the ROMOL-99 technology, the dissolving of the targets takes place under reduced pressure in a hermetically closed system.

22 Röntgen Diffractogram of the Precipitate 6000 Only reflections for Na 2 U 2 O 7 No hints for U-metal or UO Lin (Counts) Theta - Scale File: 4781 IAF WDH.RAW - Start: End: Step: Step time: 20. s - WL1: Company: TU Dresden Geologie - Creation: 03/14/06 04:12:23 Operations: Smooth Background 0.676,1.000 Import (D) - Sodium Uranium Oxide - Na2U2O7 - Y: % - d x by: 1. - WL: (D) - Uranium Oxide - UO2 - Y: % - d x by: 1. - WL: (D) - Uraninite, syn - UO2 - Y: % - d x by: 1. - WL:

23 Switch Chart of the Process Operation

24 Hot Cell Facility Operation Area

25 Hot Cell Facility Service Area

26 Filter Tower For emergency radio-iodine iodine retention Shielding: 200 mm Pb

27 Xe-delay and decay system After 7-8 weeks decay time, the remaining Xe is released into the exhaust air controlled and below safety limits

28 Intermediate Liquid Waste Storage

29 Transport Casks Target and filter cake transport Product shipment container Solid waste transport high activity Product container

30 How to assure stable Mo-99 supply? Aim As an additional option GSG suggests to think about a (very) small scale and decentralized Mo-99 production based on existing small research reactors with related Infrastructure Assist countries operating a nuclear research centre with a small RR in producing Mo-99 in small scale, to meet a country s / regional / local demand Assumed is an existing small RR (Ø n/cm 2 s) Scale GBq (10 20 Ci ) 6-days Mo-99 GSG suggests two versions / processes: ROMOL-LITE: a downscaled ROMOL-99 process based on Al-cladded LEU UAl x targets LITEMOL: Other suggestions? a process based on nat U or very low enriched U metal as target material

31 ROMOL-99 LITE Small Scale Mo-99 Production from Irradiated Al-clad. UAl x -targets with LEU Target: 20g Al, 15 g LEU as UAl x 8 weeks storage 371 ml 4 m NaNO3, 3M NaOH Dissolving process Xe, NH 3 Liq.N 2 -Trap Filtration + acidification Filter cake 200 ml 1 M HNO ml H 2 O 100 ml 0.01 M NH 4 OH 100 ml 1 M NH 4 OH 50 ml 0.1 M NH 4 OH 50 ml H 2 O 25 ml 1 M NH 4 HCO 3 2 Al 2 O 3 column process DOWEX-1 column process Iodine gas trap Exhaust system Filtrate & wash 1220 ml HLW Filtrate & wash 200 ml LLW Evaporation 1 ml conc. HNO o C High temperature treatment 20 ml 1 M NaOH Dissolving residue Final product: [ 99 Mo] Na 2 MoO 4

32 n th -flux density U-235 enrichment 7.5 E E E E g U-metal LITEMOL Exhaust H 2 -carrier gas 350 ml conc.hcl Dissolving gprocess Xe, H 2, TeH 2 Liq.N 2 -Trap N 2 -carrier gas Iodine 55 ml conc.hno 3 N 2 -carrier gas 220 ml 1 M HNO ml 1 M HNO ml H 2 O 100 ml 0.01 M NH 4 OH Oxidizing process evaporation dilution Al 2 O 3 column process 100 ml 1 M NH 4 OH 25 ml 1 M NH 4 HCO 3 Condensate 350 ml LLW Filtrate & wash 1220 ml HLW DOWEX-1 column 50 ml H 2 O Filtrate & wash 150 ml LLW Evaporation 1 ml conc. HNO o C High temperature treatment 20 ml 1 M NaOH Disolving residue Final Product: [ 99 Mo] Na 2 MoO 4

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