During the sixteenth refueling outage at Unit 2, all four
steam generators and the high pressure turbine were replaced. These replacements resulted in changes to various plant parameters, including
main steam flow rate and pressure.
PSEG developed post modification acceptance test procedure S2.PI-SP.ZZ-0001, Power Ascension Test for
HP Turbine and
Steam Generator Replacement, to support this work. The purpose of power ascension testing was to validate predicted values for
reactor coolant flow rate, pressurizer water level,
main steam flow rates and
main steam inlet pressure to the high pressure turbine. Power ascension testing was to be initiated at 18% reactor power and was to be performed in conjunction with normal plant startup procedures. During startup power ascension testing was not implemented as planned and as a result operators did not recognize that all Unit 2 high steam flow protection channels were
inoperable until the plant reached 84% power. Operators ultimately identified the condition because the steam flow rate measurement used for protection and indication was outside of acceptable limits, and entered
TS 3.0.3 and conducted a plant shutdown.
PSEG completed troubleshooting and determined that a number of engineering deficiencies and incomplete post modification test plan implementation ultimately resulted in the
inoperable high steam flow protection channels. This issue is unresolved pending
PSEGs completion of its root cause evaluation, inspector review of the root cause evaluation and additional inspector review of design control practices associated with the
steam generator replacement project. (
URI 05000311/2008003-04, Salem Unit 2 Steam Flow Feed Flow Mismatch
