ML22276A240

1) FAQ Response Provided by NEI

ML22276A240
Person / Time
Site:	Diablo Canyon
Issue date:	10/03/2022
From:	Kenneth Kolaczyk NRC/NRR/DRO/IRAB
To:
Kenneth Kolacyk, NRR/DRO, 5857738917
References
Download: ML22276A240 (1)

Text

FAQ 22-02: Diablo Canyon Scram - Proposed NRC Response The ROP Task Force recommends adding the following or similar wording highlighted in RED to the proposed resolution of the FAQ as described on page 5 of 7.

Proposed Resolution of FAQ:

Based on the guidance of NEI 99-02, Revision 7, endorsed by RIS 2000-08, Voluntary Submission of Performance Indicator Data, Revision 1, the NRC Staff concluded that the question "Was Main Feedwater unavailable or not recoverable using approved plant procedures during the scram response?" should be answered "Yes," because the steam driven main feedwater pumps were not able to be started due to the closure of MSIVs which were required to be closed specifically in response to a feedwater system issue rather than another shutdown reason (e.g., low decay heat, normal plant shutdown sequence, etc). In this case, the MSIVs were closed due to a latent failure of a feedwater heater. Additionally, the use of condensate booster pumps is not recognized by NEI 99-02 as an equivalent method to feed a steam generator as a Main Feedwater pump.

Therefore, this event should be classified as an Unplanned Scram with Complications.