ML20155G391

Describes Mod to Design of Low Temp Overpressure Protection Alarm Circuitry & Provides Schedule for Implementation of Modified Design.Mod Scheduled to Be Completed Prior to Startup Following Refueling

ML20155G391
Person / Time
Site:	Wolf Creek
Issue date:	05/02/1986
From:	Koester G KANSAS GAS & ELECTRIC CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
KMLNRC-86-071, KMLNRC-86-71, TAC-61963, NUDOCS 8605060087
Download: ML20155G391 (3)

Text

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. N KANSAS GAS AND ELECTRIC COMPANY THE ELECTCbC CCMPANY GLENN L KOE$TER m m.au uca -

May 2, 1986 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Comnission Washington, D.C. 20555 KMLNRC 86-071 Re: Docket No. STN 50-482 Ref: 1) Letter KMLNRC 85-122 from GLKoester, KG&E, to HRDenton, NRC, dated 5/22/85 2)Lecter from BJYoungblood, NRC, to GLKoester, KG&E, dated 8/16/85 Subj: Low Tenperature Overpressure Protection

Dear Mr. Denton:

This letter describes a modification to the design of low temperature overpressua protection (L'IOP) alarm circuitry described in Reference 1. A schedule for implementation of this modified design is also provided.

Reference 1 proposed reliance on existing Technical Specifications and administrative controls with the addition of alarm circuits on certain RHR/RCS suction isolation valves for UIOP. As the alarm circuit was proposed, if either valve BB-W-8702A or EJ-lW-8701B is open or does not have power available and the pressure interlock activation setpoint is reached, an alarm would annunciate in the control room. The NRC approved this design in Reference 2.

During the development cf the installation package, it was determined that the design proposed in Reference 1 would perform its intended function, but would produce alarms that could not be cleared even with correct valve aligrynent. This is because the alarms would be generated above the closure interlock activation setpoint of 682 psig when power was removed from BB-PV-8702A as procedurally required. In order to renedy this situation, Kansas Gas and Electric Company (KG&E) proposes modified alarm circuits which will alarm if either valve BB-PV-8702A or EJ-lW-8701B is open at pressures above the interlock setpoint. A single annunciator window will represent these two alarm circuits, but they will be alarmed individually on the Balance of Plant Computer.

8605060087 860502 g PDR ADOCK 05000482 P PDR l)I 201 N. Market - Wachtta, Kansas - Mail Address: PO. Box 208 I Wichita, n<ansas 67201 - Telephone: Area Code (316) 261-6451

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4 Mr. H.R. Denten KMumC 86-071 Page 2 May 2, 1986

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Figure 1 outlines the design as described in Reference 1 and the modified design. 'Ihe modified alarm circuits do not affect the analysis provided in Reference 1 with regard to conpliance to Standard Review Plans 5.2.2 and 5.4.7 and the corresponding Branch Technical Positions RSB 5-2 and RSB 5-1.

h valve position inputs for the alarms in the modified circuit come directly from valve stem mounted limit switches rather than from the motor control center inputs as in the previous design. 'Ihe modified circuit continues to provide annunciation in the control room for misaligned valves once the interlock setpoint is reached. An alarm response procedure will direct the operator to verify valve closure upon receipt of this alarm.

i h modified design requires new cables to be run to the valves in containment and requires an outage to conplete. Inplementation of this modification is scheduled to be conpleted prior to startup following

! refueling which is currently planned to begin October 9, 1986. The schedule for inplenentation of the modified design is consistant with that outlined in Wolf Creek Generating Station SSERS Section 5.2.2. '

i If you have any questions concerning this subnittal please contact me or Mr.

4 O. L. Maynard of my staff.

Very truly yours, i

Glenn L. Koester Vice President - Nuclear GLK:see Enclosure cc: PO'Connor (2)

JCumnins

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e FIGURE 1 Present NRC Approved Design '

(Ref: KMLNRC 85-122) Modified Design '

BB-W-8702A or BB-W-8702A or J EJ-IN-8701B EJ-fN-8701B 682 psig OPEN* No Power -OPEN** Interlock Setpoint l

682 psig Interlock Setpoint Cmro on Annunciator i

• Position provided by auxiliary relay at MCC

• • Position provided by valve stem mounted

, limit switches Cm non Annunciator l

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