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Lessons Learned - NRC Audits
John W. Doroski
Dominion Nuclear Connecticut / Millstone Station
Abstract
Several significant lessons have been learned from the last 5 years of NRC
Audits. These include:
Air Balance Weaknesses
 | Failure to verify BWR ventilation system performance relative to air balance (turbine
building area ventilation and steam tunnel) (Unit 1 1996 NOV) |
| Failure to verify the design basis relative to air handling capacity supplying to the
radwaste and radwaste storage buildings (same 1996 NOV as above) |
| Failure to periodic test PWR HEPA (main exhaust system, ventilation vent) performance
per FSAR requirements (Unit 2 1996 NOV) |
| Leakage through equipment hatch during outages (also see Calvert Cliffs (Greg Barley)
and Seabrook (Dave Robinson) presentations at the RETS/REMP Meeting) |
Radmonitors
| Pressure correction issue (see NRC Information Notice 82-49) |
| Usefulness of radmonitor vs grab sample trends |
| Unusually wide voltage plateaus (logarithmic display can introduce high reading errors) |
| Parameter trending (e.g., response factors, voltage, background) |
| Line in-leakage problem (see Connecticut Yankee (Jay Tarzia) presentation at 1998
RETS/REMP) |
| Sample line losses (iodines and particulates) |
Tritium Issues
| Spent Fuel Evaporation (weekly/monthly sampling not nearly sensitive enough to see
annual release of 20 curies per year) |
| Counting improvements (5 ® 20 ml vial, small correction for
sampling efficiency) |
Reporting Improvements
| Eliminate over-conservatism (rated fan flow when monitored reading is readily available) |
| Reporting less than MDA more appropriate than ND (not detectable) |
Programmatic Area
| Need overall Effluent Control Program coordinator (see Millstone (Claude Flory)
presentation at 1999 RETS/REMP Meeting) |
| Importance of clearly defined NRC I&E Bulletin 80-10 program |
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