ML20114A795

Confirms Results of 920814 Telcon Request for Temporary Waiver of Compliance from TS SR 4.3.1.1,Table 4.3-1 Re Reactor Trip Sys Instrumentation.Relief Requested Until Emergency TS Change Granted

ML20114A795
Person / Time
Site:	Wolf Creek
Issue date:	08/17/1992
From:	Bailey J WOLF CREEK NUCLEAR OPERATING CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NO-92-0246, NO-92-246, NUDOCS 9208210169
Download: ML20114A795 (5)

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W@ NUCLEAR LF CREEK OPERATING COR John A Bailey

- vice Prwoent August 17, 1992 omranons NO 92 0246

11. S. Nuclear Regulatory Commission ATTN . Document Control Desk Hail Station P1-137 Washington, D. C. 20555

Reference:

Letter NO 92-02'47 dated August 17, 1992, from J. A. <

Bailey, WCNOC to the II . S. Nuclear Regulatory Cormisalon-

Subject:

Docket No. 50-482: Request for NRR Temporary Walver of Compliance- -

Technical Specification Surveillance Requirement 4.3.1.1 Gentlemetu The- purpose of_this letter _is to confirm the results of a teleconference on Friday . August 14, 1992 at approximately 1415 CDT, in which Wolf Creek Nuclear Operating Corporation-(WCNOC) requested and the NRC staff granted a Temporary Waiver of Compliance from the requirement - of Technical Specification Surveillance Requirement _4.3.1.1 Table 4.3-1. This waiver permits continued plant operation while an Emergency Technical E, cification change is considered by the NRC Staff. _

On August' 14 , - 1992, _ at -approximately-- 1130 CDT, -a review of industry

. operation experience and % :ussions with a_ plant similar to Wolf Creek Generating Station (WCGS) had determined- a need to request a Temporary Waiver-of Compliance for _the -above surveillance requirement. Current procedures independently test the-' shunt trip and undervoltage trip functions at the breakers but do not test _the control room manual reactor trip _ switch trip. shunt contact closure. -A review of WCGS procedures and plant records determined that it was likely that; no other surveillance procedures had accomplished the intended testing, The Attachment. provides WCNOC's evaluation of the- potential safety implications of.this temporary waiver of compliance and-concludes that there _

will be no significant decrease in plant safety or the level of protection

afforded the health and safety of the public. This- proposed _ temporary- _

waiver of- compliance- has been reviewed and approved by the Plant Safety Review Committee. ,

nnnomn 9208210169 920817 f PDR ADOCK 05000482 gj P POR l PO, Box 411/ Burlington, KS 66639 i Phm.e; (316) 364 8831 a8 l

' An Equal opportunriy Employer M r HOYET 6

. 30 92-0246

- Page-?. of-2 The reference tranwitted a emergency Technical Specification change to sutvelliance requirement 4.3.1.1.

If you have any questions concerning this matter, please contact me or Hr. Kevin_J. Moles of my staff.

Very truly yours,

% [, 1/1 (,1 LIA %

John A. Bailey i

/

Vice President

. Operations- -

< JAB /jra Attachment cc A. T. Howell_(NRC), w/a

-J.=L. Hilhoan (NRC), w/a G.'A. Pick _(NRC), w/a W. D. Reckley (NRC). v/a k

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l . Attachment to NO 92 0246 Page 1 of 3 REQUEST FOR T}MPORARY WAIVER OF COMPLIANCE SPECIFIC REQUIRFHENTS FOR WHICH A TEMPORARY WAIVER IS REQUIRED Technical Specification 3.3.1 and the associated Surveillance 4.3.1.1 provide surveillance requirements for the Reactor Trip System Instrumentation. Table 4.3-1, Functional Unit 1 (Manual Reactor Trip) requires a surveillance every 18 months to independently verify operability of the shunt trip and undervoltage trip circuits for the manual trip function. A review of the current surveillance procedures indicate that, although the undervoltage and shunt trip functions are independently verified at the breaker, the control room manual reactor trip switch shunt trip contact clo are is not specifically verified. The temporary waiver of compliance (TWOC) is necessary because Technical Specification 4.0.3 requires that failure to perform Surveillance Requirement 4.3.1 within the allowed surveillance interval constitutes a noncompliance with the operability requirements for a Limiting Condition for Operation of the reactor trip system. This would require the plant to be placed in Mode 3 Hot Standby, pursuant to Technical Specification 3.0.3, within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

CIRCUMSTANCE LEADING TO NEED FOR TEMPORARY WAIVER On August 14, 1992 at approximately 1130 CDT, a review of industry cperation experience and discussions with a plant similar to Wolf Creek Generating Station (WCGS) had determined a need to request a Temporary Waiver of Compliance for the above surveillance requirement. Current procedures independently test the shunt trip and undervoltage trip functions at the breakers but do not test the control room manual reactor trip switch trip shunt contact closure. A review of WCGS procedures and plant records determined that it was likely that no other surveillance procedures had accomplished- the intended testing. Failure to-find sufficient information to indicate that the surveillance requirements had been met would have required the plant to be placed in Mode 3, pursuant to Technical Specification 3.0.3, within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

COMPENSATORY ACTIONS There is no evidence that any manual reactor trip switch hardware is inoperable. The automatic reactor trip functions meet all current surveillance requirements. WCGS Emergency Operating Procedure FR-S1,

" Response to Nuclear Power Generation /ATWT," lists alternate means of manually tripping the reactor if the manual trip switches fail. All operating crews will perform essential reading to increase their awareness of this situation. Additionally, Anticipated Transient Without Scram (ATWS) training is included in annual licensed operator training on the plant simulator.

, Attachment to 110 92 024f Page 2 of 3

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SAFETY SICNIFICANCE AND POTENTIAL CONSEQUENCES An Emergency Technical Specification change to defer the required nurveillance until the next planned or unplanned entcy inte Mode 3 in being subiaitted in the above referenced letter. The safety eveluetion for that change (Attachment I to letter NO 92-0247) is applicable t o this TWOC.

f.ince the requested action does not involve operation with deh eded or non-functional equipmer;t , the =afety impact is minimal. Independent verification of the manual shurt trip was performed during pre-operational testing. At leart once per 16 months, opening of both reactor trip breakers has been initiated by use of one of the two manual reactor trip switches in the Control Room. This operation Joes nut vtrify that both the shunt and undervoltage features function independertly. However, it does verify that the trip breakers would be opened by at least one of the two diverse means required. Credit for the manual trip is taken only as a back-up to the automatic reactor trip functions in Chapter 15 of the WCCS Updated Safety Analysis Report (USAR). Alternate means of shutting down the reactor if the manual switches oa main control board panels RbOO3 and RLOO6 do not I function, are listed in Emerp<.cy Operating Procedure FR-S1. These l includes manual operation ..'m che control room of the breakers supplying holding power to the control rods: local operations of the reactor trip breakers: manual rod insertions and immediate boration.

SIGNIFICANT HAZARDS CONSIDERATION DETFRMINATION The TWOC does not involve a significant hazards consideration because operation of WCGS in accordance with this change would not:

1. Involve a significant increase in the probability or consequences of an accident! previously evaluated.

The manual reactor trip function Trip Actuating Device Operational Test (TADOT) was correctly performed during pre-aperational testing (Pre-operational Test Procedure SU3-SB01). Since that time, due to procedural-inadequacy the manual trip surveillances did not verify the operation of control room -switch shunt contacts. Although the surveillance testing did not adequately test this portion of the manual reactor trip function, there is no reason te believe that any element of the manual trip function is not functional. If manual actuation of the shunt failed to operate, the diversity and redundancy of the reactor protection system would still enable it to perform its design function.

-The accidents evaluated in Chapter 15 of the WCGS USAR rely on the automatic trip function of the Reactor Protection System. No credit is assumed for the manual trip function. Furthermore, all surveillances performed on the automatic trip functions, with the independent verification of undervoltage trip attachment coil de-energization and shunt trip attachment energization vi.a the closing of the shunt trip relay contact, have been performri correctly. Therefore, since the response of the plant to an accident is un: hanged, there is no significant increase in either the probability or consequences of an accident previously evaluated.

,. Attachment to NO 02 0246 Page 3 of 3

2. Create the possibility of a new or different kind of accident from any previously evaluated.

The TWOC does not involve any design changes or harduate modifications ner will thero be any changes to the intended manner of plant operation or in the method by which any safety-related plant system performs its safety function. No new accident initiators, transient precursors, failure mechanisms, or limiting single failures are introduced as a result of this change.

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3. Involve a significant reduction in a margin of safety.

The TWOC does not alter the manner in which safety limits or limiting safety system settings are determined. The TWOC will have no effect on those plant systems necessary to assure the accomplishment of protection functions and meet the accident analysis acceptance criteria in Chapter 15 of the WCGS USAR. There will be no impact on Departure from Nucleate 1

Bolling Ratio limits, F , F-delta-H. Loss of Coolant Accident-Peak Clad Temperature,oranyoth0rdefinedsafetymargin.

INVIRONMENTAh CONSEQUENCES The propased TWOC involves no environmental consequences. There is no impact to accident analysis or consequences, nor does it impact systems associated with control of radiological or non-radiological effluents.

DURATION Relief from the surveillance requirements of Technical Specification 4.3.1.1, Table 4.3-1, Functional-Unit 1 for the Control Room reactor trip switch shunt trip circuits is requested until an Emergency Technical Specification change is granted. That change would allow operation until the next entry into Mode 3 to perform the surveillance and would obviate the

-.eed for this waiver. As discussed above, there is minimal safety impact of continued operation without the surveillar.ce being current since tne undervoltage trip functions of the reactor manual trip switches are tested.

Additionally, the cross trip of the shunt trip on undervoltage trip is tested on a stagger'ed test basis as required per Technical Specifications.

A manual trip switch has been demonstrated to trip the RTBs during each refueling outage.

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