ML21032A238

NRC Visual Representation of Supplemental Valve Position Testing Frequency (50.55a/ISTC-3700)

ML21032A238
Person / Time
Issue date:	02/01/2021
From:	Douglas Bollock NRC/NRR/DRO/IRIB
To:
Douglas Bollock, NRR/DRO/IRIB, 415-6609
References
Download: ML21032A238 (1)

Text

Incorrect 2 year window 2 year 2/2021 2/2017 window for 2/2019 *RFO

• RFO ISTC-3700 *RFO *ISTC-3700 Test (SPI

• ISTC-3700 Test *ISTC-3700 Test (SPI required) required) 8/2019 7/2018

• End of ISTC-3700 Grace

• 2012 OM Code per OMN-20 (if adoption applicable)

• Spring refueling outage (RFO), during which ISTC-3700 testing is performed (2/2017).

• IST Program updates to 2012 OM Code after this test (7/2018).

• Next ISTC-3700 test is due 2 years after last ISTC-3700 test (2/2019).

• 10 CFR 50.55a(b)(3)(xi) conditions the existing requirements of ISTC-3700 (states when implementing paragraph ISTC-3700) so the supplemental verification occurs on the same schedule, but may be performed at a different time within the 2 year window for ISTC-3700 testing (i.e. need not be concurrent).

This provides flexibility to conduct local observation and pressure/flow measurement for both the open and close directions.

• The wording for supplemental verification has been present as an ASME-recommended practice in the OM Code for years (as far back as OMa-1988).

• A plant could conduct supplemental verification earlier than IST Program 2012 update, or submit a proposed alternative if additional time is needed to safely perform supplemental verification.