ML17272A019

Watts Bar, Unit 1 - Technical Specification (TS) 5.9.8 - Post Accident Monitoring System (Pams) Report

ML17272A019
Person / Time
Site:	Watts Bar
Issue date:	09/29/2017
From:	Simmons P Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML17272A019 (3)

Text

Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381September 29,201710 cFR 50.4ATTN: Document Control DeskU.S. Nuclear Regulatory CommissionWashington, D.C. 20555-0001Watts Bar Nuclear Plant, Unit 1Facility Operating License No. NPF-90NRC Docket No. 50-390

Subject:

Technical Specification (TS) 5.9.8 - Post Accident Monitoring System(PAMS) ReportThe program requirements for the Watts Bar Nuclear Plant (WBN) Post Accident MonitoringSystem (PAMS) requires a report to be submitted within 14 days when Condition B ofTechnical Specification (TS) Limiting Condition for Operation 3.3.3, "Post AccidentMonitoring (PAM) lnstrumentation," is entered. On August 16,2017, containment highrange radiation monitor 1-RM-90-272 was declared inoperable. On September 15, 2017,WBN entered TS 3.3.3 Condition B for this event when the inoperable condition had beenpresent for 30 days, requiring a Special Report to the NRC. This special report is providedin the Enclosure.There are no new regulatory commitments in this letter. Please direct any questionsconcerning this matter to Kim Hulvey, WBN Licensing Manager, at (423) 365-7720.Respectfully,Paul SimmonsSite Vice PresidentWatts Bar Nuclear PlantEnclosurecc: See Page 2 U.S. Nuclear Regulatory CommissionPage 2September 29,2017cc (Enclosure):NRC Regional Administrator - Region IlNRC Senior Resident lnspector - Watts Bar Nuclear PlantNRC Project Manager - Watts Bar Nuclear Plant EnclosureTechnical Specification 5.9.8PAMS ReportBackqroundThe Watts Bar Nuclear Plant (WBN) Technical Specification (TS) 3.3.3, "Post AccidentMonitoring (PAM) lnstrumentation," specifies the operability requirements for PAMinstrumentation. TS Table 3.3.3-1, Function l2, "Containment Radiation (High Range),"requires two monitors for upper containment and two monitors for lower containment. OnAugust 16,2017, 1-RM-90-272, one of the two upper containment area radiation monitorswas declared inoperable when its green operable light would not remain lit.TS 3.3.3 Limiting Condition for Operation (LCO) Condition A allows a single indicationchannel to be inoperable for 30 days. lf the indication channel is not restored within 30days, LCO Condition B is entered, which requires action in accordance with TS 5.9.8 to betaken immediately. TS 5.9.8 requires a report to be submitted to the Nuclear RegulatoryCommission within 14 days.On-line efforts to repair this indication were unsuccessful prior to exceeding the 30 dayperiod of inoperability specified by TS 3.3.3. Parts to correct this issue were obtained afterthe 30 day period expired.This report outlines the preplanned alternate method of monitoring, the cause ofinoperability, and the plans and schedule for restoring the instrumentation channels of theFunction to OPERABLE status.Preplanned Alternate Method of MonitorinoA prompt determination of operability performed by site engineering determined themonitor will perform its safety function with the green operational light not in serviceprovided that the integrated computer system (lCS) alarm setpoint for 1-RM-90-272isactive (audible) for Operations response. ln addition, a second upper containment highrange radiation monitor remains operable and capable of providing indication during anaccident.Gause of lnoperabilitvThe issue is associated with a failed subcomponent within the ratemeter for 1-RM-90-272.Actions and Schedule to Restore lnstrumentation Function to Ooerable ConditionRepairs to 1-RM-90-272were performed and this containment radiation monitor wasreturned to a fully operable status on September 28, 2017.