Brunswick SRVs: Another Half Ass Fix Didn't Work

They should have worked this out in comprehensive testing in a similar environment.

Inadequate Procedure Resulted in Inoperable Safety Relief Valves Cornerstone Significance Cross-Cutting Aspect
Report Section
Mitigating Systems

Green NCV 05000324,05000325/2019002-03  Closed
[H.1] - Resources 71153
A self-revealed Green non-cited violation (NCV) of TS 3.4.3, “Safety/Relief Valves (SRVs)”, was identified when the licensee discovered two of the 11 safety relief valves (SRVs) asfound lift set points were outside of the +/- 3 percent pressure band required for their operability. Description:  Licensee event report (LER) 05000325/2018-003-00 was associated with two of the 11 SRVs as-found setpoints being outside of the +/- 3 percent pressure setpoint band required for their operability. This was discovered on June 11, 2018, following as-found

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testing results conducted on all 11 SRVs that were removed during the refueling outage. The licensee determined that the out of tolerance lift pressure of the two SRV pilot discs was due to corrosion bonding of the pilot disc to the valve seat. The licensee determined that these two SRVs were inoperable for an indeterminate period of time from March 23, 2016, when the unit entered Mode 2 (beginning of operating cycle) to March 3, 2018, when the unit entered Mode 4 (beginning of refueling outage). The inspectors reviewed the licensee event report and determined that the report adequately documented the summary of the event including the cause and potential safety consequences.   Corrective Actions:  The licensee replaced all eleven of the Unit 1 SRV pilot valves with refurbished valves during the Spring 2018 Unit 1 refueling outage. Corrective actions have been completed which included revised procedures and work instructions to ensure a more consistent surface preparation and proper quality checks of SRV pilot disc surface conditions prior to applying the platinum coating. Additionally, the licensee is part of the industry-led boiling water reactors owners group which is researching several new corrective actions aimed to eliminate the SRV setpoint drift issue due to corrosion bonding of the pilot valves.   Corrective Action References:  NCR 2212540 Performance Assessment:   Performance Deficiency:  Failure to provide an adequate procedure and work instructions with sufficient detail to ensure consistent pilot valve surface preparation prior to platinum coating was the Performance Deficiency. Specifically, the inadequate procedure led to a degraded platinum coating on the pilot valve seating surfaces that allowed corrosion bonding of the SRV pilot discs to pilot seats which resulted in the out of tolerance lift setpoints of the two SRVs.
 Screening:  The performance deficiency (PD) was more than minor because it affected the equipment performance attribute of the mitigating systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences (i.e., core damage).   Significance:  The significance of this finding was evaluated using IMC 0609, Appendix A, “The Significance Determination Process (SDP) for Findings At-Power,” dated June 19, 2012.  This finding was determined to be Green, very low safety significance, because all of the associated mitigating systems screening questions were answered No.  Additionally, the licensee’s Cycle 21 reload safety analysis report determined that the SRVs remained capable of performing their safety function to prevent over-pressurization of the reactor coolant system (RCS).
 Cross-Cutting Aspect:  H.1 - Resources: Leaders ensure that personnel, equipment, procedures, and other resources are available and adequate to support nuclear safety. The inspectors determined the finding had a cross-cutting aspect of Resources in the Human Performance area because adequate procedures and work instructions were not provided to ensure an adequate application of the platinum coating of the SRV pilot valve seats.
 Enforcement:   Violation:  Brunswick Steam Electric Plant, Unit 1 Limiting Condition of Operation (LCO) 3.4.3, ”Safety/Relief Valves (SRVs)” required the safety function of ten (10) SRVs shall

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be operable in Modes 1, 2 and 3. When the LCO was not met, Condition A was applicable which required that with one or more required SRVs inoperable, that the unit be in Mode 3 in 12 hours and Mode 4 in 36 hours. Contrary to the above, two required SRVs were inoperable from March 23, 2016, to March 3, 2018, and Unit 1 was not placed in Mode 3 and Mode 4 in 12 hours and 36 hours, respectively.
 Enforcement Action:  This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy...