NMC ENGINEERING IN HOT WATER WITH REGULATORS - NRC IS CONSIDERING FINING POINT BEACH - ORIFICES SUSCEPTIBLE TO CLOGGING WERE INSTALLED IN AUX FEEDWATER SYSTEM
This story consists of excerpts, slightly edited, from: J.E. Dyer (Regional Administrator, NRC Region III), letter to Nuclear Management Corp. VP for Point Beach Nuclear Power Plant, April 2, 2003:
During development of modification packages in 1999, Point Beach staff recognized the potential for AFW pump recirculation line orifices to plug. However, because of the lack of understanding of AFW design basis, the orifices were installed. In late 2001 and early 2002, an AFW/Instrument Air issue presented an opportunity to correct this lack of understanding, but no action was taken until the orifice for the ÒAÓ motor-driven AFW pump was found partially plugged on October 24, 2002, after post-maintenance testing of the pump. In February 2003, testing conducted for Point Beach by an independent laboratory demonstrated that the orifices would quickly plug when subjected to water-borne debris similar to that found in Point Beach's service water system. The installation of the orifices is an apparent violation of 10 CFR Part 50, Appendix B, Criterion III, "Design Control"... The apparent violation is being considered for escalated enforcement action ...
NRC also identified other problems related to AFW design, including the use of a nonsafety-related power supply for relays (the relays associated with the operation of the AFW recirculation line air-operated flow control valves) and the single electrical bus dependencies of three of the four recirculation line air-operated flow control valves and three of the four service water supply motor-operated valves.
NRC concluded that all the above problems represent deficiency in Point Beach engineering program -- a failure to implement thorough and complete corrective actions to prevent recurrence of potential common mode failures of AFW pumps. The failure to implement adequate corrective actions for the AFW/IA issue is a violation of 10 CFR Part 50, Appendix B, Criterion XVI, "Corrective Action". This violation also precludes NRC's administrative classification of the AFW/IA problem as an old design issue. This means that Point Beach is now in what NRC calls the Multiple/Repetitive Degraded Cornerstone Column of the Action Matrix of Manual Chapter 0305. Consequently, Point Beach will be discussed at the upcoming Agency Action Review Meeting.
Ref: See pdf file of NRC's letter, and the accompanying inspection report report 50-266/2002-15
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composed April 5, 2003, based on document released by NRC on April 4
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