Severity Level IV. The inspectors identified a
Severity Level IV Non-Cited Violation associated with the failure to report
residual heat removal (
RHR) train 'B' unavailability from May 29, 2004, through June 3, 2004, while the emergency
service water train B was inoperable for pump repairs. The second quarter 2004 data reported to the NRC included
RHR 'A' unavailability following failure of the
ESW 'A' pump on May 21, 2004, but did not include the subsequent
RHR 'B' unavailability. Prior to removing the
ESW 'B' pump from service, the licensee developed a
reactor pressure vessel feed and bleed method which they subsequently credited as an alternate
decay heat removal system when calculating
RHR system unavailability. The inspectors, however, reviewed the definitions and guidance contained in
Nuclear Energy Institute (NEI) 99-02, Regulatory Assessment Indicator Guideline, Rev. 2, and could not conclude that the licensees method met the NRC approved method of
decay heat removal. Due to the inspectors' concerns, the licensee submitted a Frequently Asked Question. On May 19, 2005, the NRC determined that NRC approval means a specific method or methods described in the technical specifications. As a result, the licensee recalculated and resubmitted
RHR system unavailability on June 17, 2005. Had the performance indicator (
PI) data been properly reported in the second quarter of 2004, the
PI color would have been White. The failure to properly report the
PI was considered a
Severity Level IV Non- Cited Violation of
10 CFR 50.9.
