2. 1 Update: Te-125m in Liquid Waste RETS REMP Workshop June 25, 2008 Richard Conatser Constellation Energy Group Calvert Cliffs Nuclear Power Plant

3. 2 Overview u Te-125m Basics u Review of 2006 Presentation u Empirical Data for Te-125m at CCNPP u Production of Te-125m u Corrective Actions u Questions

4. 3 Te-125m Basics u Te-125m is a gamma emitter u 57.4 day half life u Production: Beta decay of Sb-125 u Te-125m emits 109 keV gamma u 109 keV Abundance = 0.283% u A few counts = “high” activity

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14. 13 Fact Sheet (“Knowns”) u Te-125m in 1 st or 2 nd Qtr. Only u RFOs always in 1 st Qtr. u RFO-related activities are 1 st Qtr u Te-125m from processed waste u Te-125m has appeared immediately before a RFO

15. 14 Production of Te-125m u Sb-125 is concentrated (e.g., IX, filter) u Sb-125 decays to Te-125m u Te-125m is selectively released u Te-125m is not removed in LRW purification To control Te-125m, stop one or more of the above production steps

16. 15 Corrective Actions u Control Te-125m with LRW purification u “Fresh” IXs mitigated Te-125m u In 2007, chemicals dumped to LRW system u Made “fresh” IXs ineffective u Researched alternative strategies u Needed robust removal media u Purchased Specialty Resin (ASM-125)

17. 16 ASM-125 Resin u Iron impregnated anion resin u Developed for Group V metals u Able to strongly retain contaminants u Less susceptible to soughing u More expensive/long run time u Costs are competitive u Several Vendors

18. 17 Simplified Diagram 11 RCWRT 90,000 gal UF 6 B/W Tk #14 IX 0-RCW-526 Demin Booster Pump Recirculation Pump Chem Add Tank DI Water 11 RCWMT Pump 0-RCW-522 0-RCW-518 12 RCWRT 90,000 gal RCWRT pumps 11 RCWMT 90,000 gal SCS #13 IX 12 RCWMT 90,000 gal #4 IX #2 IX #1 IX #3 IX UF 5UF 4 UF 3UF 2UF 1 Bay

19. 18 Experience with ASM-125 u We’ve reprocessed 4 tanks u Reprocessing removed Te-125m u Te-125m was discharged in 2008 u That was because of maintenance issues (prevented reprocessing 2 tanks)

20. 19 Te-125m Learnings u Te-125m origin: Not LRW IXs? u Concentrating mechanism is thought to be IXs u Te-125m appears prior to RFO u Te-125m related to RFO supporting activities u May be related to spent CVCS IXs

21. 20 Questions?