On March 25, 2018 at 1833
CDT, while at 100 percent power, Farley Unit 1 (FNP-1) conservatively declared a single
Main Steam Isolation Valve (
MSIV)
inoperable on the 1C
Steam Generator line due to indication of
Steam Generator pressure rise with a corresponding reduction in flow of that loop. FNP-1 began a reactor shutdown at 0400
CDT on March 26, 2018 to establish plant conditions to support testing the affected
main steam line MSIVs while in the required action time of
Technical Specification 3.7.2. At 1338
CDT on March 26, 2018, testing confirmed that the single
MSIV was
inoperable and that valve disassembly will be required. The duration of the valve repair would exceed the required action time of
Technical Specification 3.7.2. This report is being made in accordance with 10 CFR 50.72(b)(2)(i), as a plant shutdown required by technical specifications.
The licensee has notified the NRC Resident Inspector.
- * * UPDATE FROM DOUGLAS HOBSON TO KEN MOTT AT 0202 EDT ON 5/16/18 * * *
This EN [event notification] is being updated to clarify the reporting criteria as 'Voluntary'. Farley Technical Specification 3.7.2 allows continuous operation in MODE 2 with an INOPERABLE MSIV as long as the other MSIV in the affected Main Steam Line is closed. The initiation of the shutdown was performed as a prudent action to repair and restore OPERABILITY of the affected MSIV and was not a requirement of the Farley Technical Specifications.
The licensee notified the NRC Resident Inspector.
The R2DO (Masters) was notified.