WO 15-0045, Technical Specification 5.6.8 - Post Accident Monitoring (PAM) Report

Technical Specification 5.6.8 - Post Accident Monitoring (PAM) Report

ML15215A367
Person / Time
Site:	Wolf Creek
Issue date:	07/27/2015
From:	Shawn Smith Wolf Creek
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
WO 15-0045
Download: ML15215A367 (2)

Text

• 'CREEK SOPERATING CORPORATION July 27, 2015 Stephen L. Smith Plant Manager WO 15-0045 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555

Subject:

Docket No. 50-482: "Technical Specification 5.6.8 - Post Accident Monitoring (PAM) Report Gentlemen:

The Attachment provides the PAM Report for the inoperability of the Reactor Vessel Water Level Function for greater than 30 days. Wolf Creek Generating Station Technical Specification (TS) 5.6.8, "PAM Report," requires the submittal of the report within 14 days after entry into Condition B of TS 3.3.3, "Post Accident Monitoring (PAM) Instrumentation." Condition B of TS 3.3.3 was entered on July 13, 2015. This condition was entered due to a Reactor Vessel Level Indicating System (RVLIS) train (TS Table 3.3.3-1, Function 5) being inoperable.

This letter contains no commitments. If you have any questions concerning this matter, please contact me at (620) 364-4093, or Mr. William T. Muilenburg at (620) 364-4186.

Sincerely, Stephen L. Smith S LS/rlt Attachment cc: M. L. Dapas (NRC), w/a C. F. Lyon (NRC), w/a A. A. Rosebrook (NRC), w/a Senior Resident Inspector (NRC), w/a 41~L9I PRO. Box 411!/ Burlington, KS 66839 / Phone: (620) 364-8831 An Equal Opportunity Employer M/F/HC/VET

Attachment to WO 15-0045 Page 1 of 1 Technical Specification 5.6.8 - Post Accident Monitoring (PAM) Report Backgqround On June 13, 2015, Control Room operators observed the resistance temperature detector (RTD) BBTE1324 output for the 'B' train of Reactor Vessel Level Indication System (RVLIS) had failed. At 1455 hours0.0168 days <br />0.404 hours <br />0.00241 weeks <br />5.536275e-4 months <br /> Central Daylight Time (CDT), Technical Specification (TS) 3.3.3, "Post Accident Monitoring (PAM) Instrumentation," Condition A was entered when a Reactor Vessel Water Level channel was determined to be inoperable. TS Table 3.3.3-1, Function 5, "Reactor Vessel Water Level," requires 2 channels to be OPERABLE. Required Action A.1 of TS 3.3.3 requires restoring the required channel to OPERABLE status within 30 days. On July 13, 2015, TS 3.3.3 Condition B was entered when the Required Action and associated Completion Time of Condition A was not met. Required Action B.1 requires initiation of action in accordance with TS 5.6.8, "PAM Report," and requires that a report be submitted within 14 days after entry into Condition B.

Reactor Vessel Water Level is a Type B, Category 1 variable provided for verification and long term surveillance of core cooling. It is also used for accident diagnosis and to determine reactor coolant inventory adequacy. The RVLIS provides an indication of reactor vessel water level from the bottom of the reactor vessel to the top of the reactor during natural circulation conditions and an indication of reactor core and internals pressure drop for any combination of operating reactor coolant pumps. The RVLIS consists of four reactor vessel water level indicators divided into two separate trains; each includes a narrow range and wide range indication. A channel is considered a train. A channel is considered OPERABLE when both its narrow range and wide range indicators are OPERABLE.

Preplanned Alternate Method of Monitoringq Alternate means of monitoring reactor vessel water level are available to Control Room operators while the 'B' train of RVLIS is not OPERABLE. Additional PAM instrumentation that provides for verification of core cooling and long term surveillance include the 'A' train of RVLIS (Function 5), reactor coolant system subcooling monitor (Function 4), pressurizer level indication (Function 11), and core exit temperature (Functions 14, 15, 16, and 17).

Cause of Inoperability On June 13, 2015, Control Room operators observed the resistance temperature detector (RTD) BBTE1 324 was indicating a failed low condition on the Nuclear Plant Information System (NPIS). Further testing on July 1, 2015 did not find a definitive cause for the failure of BBTE1 324.

Plans and Schedule for Restorinq the Instrumentation Channel of the Function to Operable Status The RVLIS RTDs and corresponding leads to the instrument channels are located inside the secondary shield wall and are inaccessible to personnel while operating at power due to radiological conditions in this area that prohibit access by plant personnel. Further troubleshooting may only be done during shutdown periods. Additional troubleshooting and necessary corrective actions is planned for Refueling Outage 21 (Fall 2016) unless the actions are taken during a forced outage prior to the refueling outage.