A finding of low to moderate safety significance wa
identified where engineering staff did not properly evaluate and correct
degraded level control valve for the i12Ai12 moisture separator drain tank, as require
by station procedures. In addition, engineers did not properly consider a simila
occurrence from 1988. The level control valve failed 25 days prior to the even
and caused the moisture separator drain system to operate in a condition outsid
its design. As a result, an 8-inch pipe in that system failed and caused the even
on October 10, 2004
This issue is greater than minor because it is associated with the Equipmen
Performance attribute of the Initiating Events cornerstone and affected th
objective of limiting the likelihood of events that upset plant stability an
challenge critical safety functions. A Significance Determination Process Phas
2 risk analysis determined that this finding had low to moderate safet
significance based on the increased frequency of a transient with the loss of th
power conversion system initiating event over the 25-day exposure period.
(Section 3.3)
