2. 1 Fe-55 and Te-125m in Liquid Waste RETS REMP Workshop June 26-28, 2006 Richard Conatser Constellation Energy Group Calvert Cliffs Nuclear Power Plant

3. 2 Overview u Radwaste history, cost, and strategy u Empirical Data (Te-125m and Fe-55) u Radwaste System Overview u Corrective Actions/Recommendations u Questions

4. 3 CCNPP LRW History u Before 2003 releases were 3 rd quartile u Large volume processed (2.2E6 gal/yr) u OEM used filters, IX, and evaporators u Filter use was excessive at times u High disposal costs

5. 4 Costs Before the “Skid” u $1.3M cost in 2001 (excluding labor) u Estimated $0.45/gal (excl. labor) u Processing used to be slow u Lots of dose associated with filters u LRW was typically 3 rd Quartile u Evaluated advanced “skids” u Determined costs could be reduced

6. 5 Strategy u Lower Ci discharged u Reduce costs to $0.22/gallon u Reduce dose u Reduce man-hours u Achieve INPO 1 st quartile

9. 8 Fe-55 u Produced from Fe-54 (5% abn.) u Fe-55 decays by electron capture u emits low-energy x-rays u emits Auger electrons u 2.77 year half life u Separation and scintillation counting

11. 10 Potential Causes Fe-55 u Analytical Method? u Composite Sample (prep.)? u Radwaste Processing? u Real System Anomaly?

12. 11 Analytical Method Fe-55 u Separate Fe-55 (precipitation, IX) u Liquid scintillation counting u Gross analysis (energy window) u Susceptible to interference u QC standards were good u “D.I. Blank” was high u No spike sample

13. 12 Composite Sample Fe-55 u Two sources of radwaste water u High Conductivity (soapy drains) u Low Conductivity u High cond waste is not processed u Qualitative trend appears normal u Some history of sample prep problems

14. 13 Radwaste Process, Fe-55 u First noticed coincident with skid u Easily removed as a particulate u Expect removal similar to Cobalt u Data = Doesn’t follow other nuclides u Data = Concentrating Fe-55 u Data = Effectively bypassing skid

15. 14 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

16. 15 Corrective Actions Fe-55 u Maintain spare composite sample u Include spiked samples u SCS samples analyzed for Fe-55 u Trace all flow paths for “skid”

17. 16 Te-125m u Te-125m is a gamma emitter u 57.4 day half life u From beta decay of Sb-125 u Te-125m emits 109 keV gamma u 109 keV Abundance = 0.283% u A few counts = “high” activity

19. 18 Corrective Actions Te-125m u This phenomena appears to be related to IXs u May be related to changes in feed water quality u Change IXs more often

21. 20 Questions?