ML13074A705
| ML13074A705 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 03/15/2013 |
| From: | Cleary T Tennessee Valley Authority |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| Download: ML13074A705 (4) | |
Text
Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381 March 15, 2013 TS 5.9.8 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Unit 1 Facility Operating License No. NPF-90 NRC Docket No. 50-390
Subject:
Technical Specification (TS) 5.9.8 - Post Accident Monitoring Report (PAM) -
Upper Gontainment Radiation Monitor On March 1,2013, Technical Specification Limiting Condition for Operation (LCO) 3.3.3, Condition B, was entered for inoperability of one PAM channel of the upper containment radiation instrumentation. Condition B requires immediate initiation of a PAM report within 14 days in accordance with Technical Specification 5.9.8. Accordingly, TVA has provided the PAM report in Enclosure 1. A commitment to restore operability is provided in Enclosure 2. Should you require additional information regarding this matter, please contact Ms. Donna Guinn, Site Licensing Manager, at (423) 365-1589.
Respectfully, ry%,
Timothy P. @leary Site Vice President Watts Bar Nuclear Plant Enclosure cc: See Page 2
U.S. Nuclear Regulatory Commission Page 2 March 15, 2013 Enclosure cc (Enclosure):
NRC Regional Administrator - Region ll NRC Senior Resident Inspector - Watts Bar Nuclear Plant
Enclosure I Technical Specification 5.9.8 Post Accident Monitoring System Report Upper Containment Radiation Monitor Backqround On February 1,2013, at 0658 hours0.00762 days <br />0.183 hours <br />0.00109 weeks <br />2.50369e-4 months <br /> (EDT), the plant entered Limiting Condition of Operability (LCO) 3.3.3, Condition A due to spurious high range spiking on upper containment high range radiation instrument loop 1-LPR-90-272 (PAM Instrument Channel2). TS Table 3.3.3-1, Function 12, requires that two PAM channels be OPERABLE. Condition A also requires that the channel be restored to OPERABLE status within 30 days. On March 3,2013, Condition B of LCO 3.3.3 was entered due to failure to meet the Completion Time specified in Condition A.
Condition B requires that a report be issued in within 14 days in accordance with TS 5.9.8.
PAM lnstrument Channel 1 (1-LPR-90-271) has remained OPERABLE during the entire time PAM Channel 2 has been inoperable.
Upper containment radiation loop 1-LRP-90-272 is a PAM Type A, C, and E variable with a category Class 1 Qualification. The upper containment radiation instrument loops provide primary indications (Type A) to allow the reactor operator to take preplanned manually controlled actions for which no automatic action is provided and that are required for safety systems to accomplish their safety functions for Chapter 15 design basis events. They are also key variables (Type C) that indicates the accomplishment of required safety functions and the magnitude of the release of radioactive materials (Type E).
Preplanned Alternate Method of Monitorinq Radiation Instrument Loop 1-LPR-90-272 is functioning at this time and is providing valid data.
Although functional, this channelwill not be declared OPERABLE until repairs are made and sufficient time has elapsed to confirm that the spurious high range spiking has been resolved.
This issue has been entered into the Corrective Action Program as PER 691431. Upper containment high range radiation monitoring is currently performed by instrument loop 1-LPR-90-271(PAM Instrument Channel 2) which is OPERABLE and has remained operable during this time.
The Gause of the Inoperabilitv The most probable cause of spiking is due to high impedance caused by a loose or deteriorating connector(s) in the main control room board and is most likely due to aging.
Plans and Schedule for Restorinq Function to Operable Condition TVA plans to restore Instrument Loop 1-LPR-90-272 operability by repairing the connector(s) and monitoring for spurious indications. The instrument loop will be monitored until sufficient time (based on previous trend data) has elapsed such that plant operators confirm that the spurious operation experienced has been resolved.
Technical Specification 5.9.8 Post Accident Monitoring System Report Upper Containment Radiation Monitor Gommitment Upper Containment Radiation Instrument Loop 1-LPR-90-272will be repaired within 30 days from the date of this letter and monitored until sufficient time has elapsed such that plant operators confirm that the spurious high range spiking has been resolved.