ML17286A540

Application for Amend to License NPF-21,changing Tech Specs Re Scram Discharge Vol Level Setpoints

ML17286A540
Person / Time
Site:	Columbia
Issue date:	12/31/1990
From:	Sorensen G WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML17286A541	List: ML17286A540 ML17286A542
References
GO2-90-209, NUDOCS 9101100002
Download: ML17286A540 (10)

Text

ACCELERATED DISTRIBUTION DEMONSTRATION SYSTEM I

~ Pi 'EGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9101100002 DOC.DATE: 90/12/31 NOTARIZED: YES DOCKET g FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION SORENSEN,G.C. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Application for amend to License NPF-21,changing Tech Specs re scram discharge vol level setpoints.

DISTRIBUTION CODE: AOOID TITLE: OR COPIES RECEIVED:LTR Submittal: General Distribution J ENCL  ! SIZE:

NOTES RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1 ENG,P.L. 2 2 INTERNAL: ACRS 6 6 NRR/DET/ECMB 9H 1 1 NRR/DET/ESGB 1 1 NRR/DOEA/OTS B1 1 1 1 NRR/DST 8E2 1 1 NRR/DST/SELB 8D 1 1 NRR/DST/SICB 7E 1 1 NRR/DST/SRXB 8E 1 1 NUDOCS-ABSTRACT 1 1 OC 1 0 OGC/HDS2 1 0 G FIL 01 1 1 RES/DSIR/EIB 1 1 EXTERNAL: NRC PDR NSIC 1 1 NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISP) FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 24 ENCL 22

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WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ 3000 George Washington Way ~ Richland, Washington 99352 December 31, 1990 G02-90-209 Docket No. 50-397 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Gentlemen:

Subject:

NUCLEAR PLANT NO. 2, OPERATING LICENSE NPF-21 REQUEST FOR AMENDMENT TO TECHNICAL SPECIFICATIONS, SCRAM DISCHARGE VOLUME SETPOINTS In accordance with the Code of Federal Regulations, Title 10, Parts 50.90 and

2. 101 the Supply System hereby submits a request for an amendment to the WNP-2 Technical Specifications and Bases describing Scram Discharge Volume (SDV) level setpoints (see attached).

The SDV is provided to receive and contain the water discharged from the control rod drives (CRD) during a scram, thereby limiting the loss of water from the reactor vessel and providing a primary containment boundary. Alarm, rod block and scram signals are provided from SDV level instruments so that manual or automatic actions can occur to ensure that adequate free volume remains in the system to accommodate the water from a scram at any time. A recent modification to the system, accomplished to reduce stay time and personnel exposure while performing maintenance on the system, added gauge glasses to facilitate calibration of the level sensing instrumentation. In completing this modifica-tion grade surveys were done to calibrate the gauge glasses. The grade surveys provided an accurate elevation reference on the new gauge glass assemblies. The new calibration procedures and hardware eliminated subtle inaccuracies that were present in the procedures and system prior to the gauge glass modification. As a result, the calibration of the level switches to current Technical Specification setpoints is not achievable because the level switches do not have sufficient span, as installed, to be adjusted to present setpoints. The previous

( 9101100002 901231 PDR ADOCK 05000397 P PDR

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Page Two RE(VEST FOR AMENDMENT TO TECHNICAL SPECIFICATIONS, SCRAM DISCHARGE VOLUME SETPOINTS trip setpoint, 529'" shown on Table 2.2. 1-1 of the WNP-2 Technical Specifications, is approximately 1/2" (worst case for the 4 Scram Level Switches) below the lowest adjustment span of the level switches as currently installed.

The level switches on the volumes are permanently mounted such that the low end of the calibration span of the switches is, by the previous reference, very near to the 529'" point. With the new reference the lower to mid adjustment span of the switch is nearer 529'" and attempting to set it at 529'" allows little or no room for adjustment. As a result to ensure the instruments are not set at the low stops and allow satisfactory calibration of the instruments the proposed change recognizes the new elevation of 529'" as an appropriate trip setpoint.

As shown in the proposed change to the bases 64.9 gallons of margin is provided in free volume above the 617.9 gallons required for a reactor scram at this setpoint. This represents a decrease in the margin of approximately 0.8%.

The same situation is resolved for the Rod Block instrumentation setpoint on Table 3.3.6-2. The Scram Discharge Volume Water Level - High trip setpoint is changed from 527'" to 527'". The same reference level error for this trip setpoint was discovered with the installation of the gauge glasses. This change represents a decrease in the previous margin of approximately 0.5%.

It should be noted that both of these setpoints are conservative with respect listed Allowable Values for these parameters and as such invoking the ACTION to'he statement requiring the channels to be declared inoperable is not applicable.

However in order to allow the same margin for setpoint drift as currently provided the Allowable Values for both the SDV Water Level - High Scram and Rod Block should be increased by one inch to 529'" and 527'" respectively.

Margin decrease as a result of these changes is again, approximately 0.8% and 0.5% respectively for the Scram and Rod Block functions.

In reviewing the Bases for this change it was recognized that the present bases provides no method for determining what amount of margin remains and the significance of the various level setpoints with respect to the system safety function. As a result the Bases should be changed as proposed. The new Bases provides both elevation and existing safety margins.

The Supply System has evaluated this amendment per 10 CFR 50.92 and determined that it does not represent a significant hazard because =-it does not:

1) Involve a significant increase in the probability or consequences of an accident previously evaluated because as discussed the decrease in the trip setpoints and Allowable Values is insignificant. In both margin'or cases less than 0.8%. Therefore the probability or consequences of an accident previously evaluated are not significantly increased by these changes.

2) Create the possibility of a new or different kind of accident from any accident previously evaluated because SDV operation, including the Scram and Rod Block functions, remains unaffected. No new modes of operation of any equipment result due to this change. Therefore this change will not result in, nor create, a new or different kind of accident from any accident previously evaluated.

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Page Three RE(UEST FOR AMENDMENT TO TECHNICAL SPECIFICATIONS,

'SCRAM DISCHARGE VOLUME SETPOINTS

3) Involve a significant reduction in a margin of safety because, as discussed above, the reduction in margins represented by these changes is insignificant, less than 0.8%. Therefore, this change will not involve a significant reduction in the margin of safety.

As discussed above, the Supply System considers that this change does not involve a significant hazards consideration, nor is there a potential for significant change in the types or significant increase in the amount of any effluents that may be released offsite, nor does it involve a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed change meets the eligibility criteria for categorical exclusions set forth in 10 CFR 51.22(c)(9) and therefore, per 10 CFR 51.22(B), an environmental assessment of the change is not required.

This amendment request has been reviewed and approved by the WNP-2 Plant Operations Committee (POC) and the Supply System Corporate Nuclear Safety Review Board (CNSRB). In accordance with 10 CFR 50.91 the State of Washington has been provided a copy of this letter.

Very truly ours, G. C. Sorensen, Manager Regulatory Programs PLP/bk Attachments cc: JB Hartin - NRC RV NS Reynolds - BCP&R PL Eng - NRC DL Williams - BPA/399 NRC Site Inspector - 901A RG Waldo - EFSEC

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Request for Tech Spec Amendment STATE OF WASHINGTON)

Subject:

Scram Dischar e Volume Se oint

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COUNTY OF BENTON )

I, G. C. SORENSEN, being duly sworn, subscribe to and say that I am the Manager, Regulatory Programs, for the WASHINGTON PUBLIC POWER 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, information, and belief the statements made in it are true.

DATE: , 1990 G. C. Sorensen, Manager

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Regulatory Programs On this date personally appeared before me G. C. SORENSEN, 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 ~lst day of 1990.

~i~~- 2 Notary Public in and for the STATE OF WASHINGTON Residing at My Commission Expires

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