ML17279A551

Requests Temporary Relief from Tech Spec Table 3.3.2-2,Item 1, Main Steam Line Tunnel Temp - High Re Increase in Trip Setpoint Value from 150 F to 156 F.Tech Spec Change to Address Inviolate Definition Concern Will Be Submitted

ML17279A551
Person / Time
Site:	Columbia
Issue date:	09/01/1987
From:	Sorensen G WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
GO2-87-239, TAC-66074, NUDOCS 8709100250
Download: ML17279A551 (9)

Text

P -UL ORY INFORMATION DISTR T SYSTEM (RIDB)

ACC SSION NBR: 8709100250 DOC. DATE: 87/09/01 NOTARIZED: YES DOCKET 0 FACIL: 50-397 NPPSS Nuclear Progecti Unit 2i Nashington Public Poee 05000397 AUTH. NAME AUTHOR AFFILIATION SORENSENi Q. C. Washington Public Power Supply System RECIP. NAME RECIPIENT AFFILIATION Document Control Branch <Document Control Desk)

SUBJECT:

Requests temporary r elief from Tech Spec Table 3. 3. 2-2i Item ii "Main Steam Line Tunnel Temp Highi" re increase in trip setpoint value From 150 F to 156 F. Tech Spec change to address "inviolate" definition concern mill be submitted.

DISTRIBUTION CODE: A001D TITLE: OR COPIES RECEIVED: LTR Submittal: Qeneral Distribution l ENCL + SIZE:

NOTES:

RECIPIENT COP IEB RECIPIENT COP I EB ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 0 PD5 PD 5 5 BAMWORTH> R 1 1 INTERNAL: ACRB 6 6 ARM/DAF/LFMB 1 0 NRR/DEBT/ADS 1 NRR/DEBT/CEB NRR/DEBT/MTB 1 1 NRR/DEBT/RSB 1 1 NRR/DOEA/TSH 1 1 NRR/PMAB/ILRB 1 1 OQC/HDS2 1 0 01 1 1 RES/DE/EIH 1 EXTERNAL: EQ8cQ BRUSKE> S 1 1 LPDR 1 NRC PDR 1 1 NSIC 1 1 TOTAL NUMBER OF COPIES REGUIRED: LTTR 27 ENCL 24

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Washington Public Power Supply System 3000 George Washington Way P.O. Box 968 Richiand, Washington 99352-0968 (509)372-5000 September 1, 1987 G02-87-239 Docket No. 50-397 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Nashington, D.C. 20555 Gentlemen:

Subject:

NUCLEAR PLANT NO. 2 OPERATING LICENSE NPF-21 REQUEST FOR TEMPORARY RELIEF, TECHNICAL SPECIFICATION TABLE 3.3.2-2

Reference:

Letter, G02-85-238, G. C. Sorensen (SS) to A. Schwencer (NRC), "Setpoint Methodology for NNP-2", dated May 6, 1985 The subject Technical Specification Table item 1.d, Main Steam Leone Tunnel Temperature High, lists a trip setpoint value of 150 F.

Upon issuance of the Technical Specifications, the value was utilized with the belief that the Bases statement Section 3/4.3.2: "operation with a trip set less conservative than its Trip Setpoint but within its allowable value is acceptable" provided guidance on the use of the value and application of an acceptable band around that value.

Recsntly, temperatures in the main steam tunnel have approached the 150 F value to the extent that continued operation is in jeopardy.

Using what was considered the trip setpoint acceptable range and what was felt to be guidance provided by the Bases, tge trip setpoint has been readjusted within the acceptable range to 156 F. This value, per the setpoint methodology described in the reference, does ensure the allowable value, 170 F, will not be exceeded.

The Supply System has recently become aware that the Trip Setpoint as presented in the Technical Specification Tables are now to be viewed as inviolate which would preclude operation witH a setpoint greater than 150limits F. Resetting the setpoint to 150 F, given present conditions, would cause a group one isolation and reactor scram.

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Page two Request for Temporary Relief, TS 3.3.2-2 Relief is requested on the bases that a Trip Setpoint at a value of 156 F will not create a significant hazards concern. A Technical Specification change will be submitted separately to address this programmatic concern under the "inviolate" definition. In the interim, the assertion that no significant hazards concern is presented is based on assuring that the allowable value is not exceeded. The original calculation performed to establish the leak detection high ambient temperatures analytical limit was based upon an equivalent 25 gpm condensate leak which resulted in 185 F tunnel temperature. The allowable value was an adjustment applied to the analytical limit accounting for 7 degrees of loop calibration uncertainty/inaccuracy and 6 degrees of additional margin combined by the square root of the sum of the squares method as described in Exhibit III of the reference letter. This would have produced an allowable value of 175.8 F but was conservatively reduced to 170 F as the submitted Technical Specification Allowable Value. A trip setpoint limit was arrived'at by further reducing the allowable value for instr ument drift of 6 degrees yielding 164 F. The 150 F trip setpoint was arrived at by consideration of long term plant life concrete degradation effects not attributable to instrumentation constraints and presenting no immediate significant hazards concern.

0 The 164 F value accounts for drift, total 'oop inaccuracy and calibration err or providing a 21 degree margin to the analytical limit. The 6 degree margin to the Allowable Value accounts for the maximum expected instrumentation drift between required calibration frequencies of 18 months. Additionally, a 164 F value would put the setpoint in concurrence with other plants licensed after WNP-2 such as Susquehanna and Fermi whose trip setpoint differs from the Allowable Value by only the instrument dr ift margin of 7 and 6 degrees, respectively. Hence, operation at 156 F is well within margin. Given the amount of margin and the drift experienced to date (<3 F) no compensatory measures are deemed appropriate.

It should be noted that the Supply System did recognize steam tunnel cooling as a recurrent problem and took action during previous refueling outages to solve the problem. Insulation problems were corrected and a modification to provide cooler water to the steam tunnel heat exchanger s was completed.

The circumstances producing the need for relief could not have been anticipated as the Supply System believed the actions taken would solve the problem and could not anticipate the Staff's interpretation of how to apply the trip setpoints in our instrumentation calibration program.

Page three Request for Temporary Relief; TS Table 3.3.2-2 Based on the fact that the present setting, 156 F will not cause the Allowable Value to be exceeded and the assertion that no significant hazard is present by this value, present operation does not represent an undue risk to the health and safety of the public. Additionally, absent this relief, the WNP-2 plant will be placed in a position requiring plant shutdown.

Should you have any'uestions, please contact Mr. P. L. Powell, Manager, WNP-2 Licensing.

Very truly yours, c..

G. C. Sorensen, Manager Regulatory Programs PLP/tmh cc: C Eschels - EFSEC G Knighton - NRC JB Martin NRC RV NS Reynolds

'- BCP8R RB Samworth - NRC DL Williams - BPA NRC SiteInspector - 901A

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CO rqI Request for Temporar'y Relief b t. TS Table 3.3.2-2 STATE OF WASHINGTON ) S

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COUNTY OF BENTON )

I, P. L. POHELL, being dully sworn, subscribe to and say that I am acting for the Manager, Regulatory Programs, for the WASHINGTON PUBLIC POHER SUPPLY SYSTEM, the applicant herein; that I have full authority to execute this oath; that I have reviewed the foregoing; and that to the best of my knowledge, infor mation and belief the statements made in it are true.

1987 P. L. POHELL, Acting Manager Regulatory Programs On this day personally appeared before me P. L. POHELL to me known to be the individual who executed the foregoing instrument and acknowledged that he signed the same as his free act and deed for the uses and purposes herein mentioned.

GIVEN under my hand and seal this 1st day of September ,1987.

Notary Pu lac n and for the State of Washington Residing at Kennewick, WA

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