GO2-97-068, Ro:On 970327,reactor Scrammed.Evaluation Results,Conclusions & Corrective Actions Will Be Shared W/Nrc Prior to Plant Startup from Maint & Refueling Outage

Ro:On 970327,reactor Scrammed.Evaluation Results,Conclusions & Corrective Actions Will Be Shared W/Nrc Prior to Plant Startup from Maint & Refueling Outage

ML17292A792
Person / Time
Site:	Columbia
Issue date:	04/09/1997
From:	Parrish J WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	Merschoff E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
GO2-97-068, GO2-97-68, NUDOCS 9704150215
Download: ML17292A792 (5)

Text

e CATEGORY 0 REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9704150215 DOC.DATE: 97/04/09 NOTARIZED: NO FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe AUTH.NAME AUTHOR AFFILIATION PARRISH,J.V.

Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION MERSCHOFF,E.W.

Region 4 (Post 820201)

DOCKET g

05000397

SUBJECT:

RO:on 970327,reactor scrammed. Evaluation results, conclusions a corrective actions will be shared w/NRC prior to plant startup from maint a refueling outage.

DISTRIBUTION CODE:

ZE22D COPIES RECEIVED:LTR j ENCL Q SIZE: 3 TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

NOTES:

RECIPIENT ID CODE/NAME PD4-2 PD INTERNAL: ACRS AEOD/SPD/RRAB NRR/DE/ECGB NRR/DE/EMEB NRR/DRCH/HICB NRR/DRCH/HQMB NRR/DSSA/SPLB RES/DET/EIB EXTERNAL: L ST LOBBY WARD NOAC POOREFW.

NRC PDR COPIES LTTR ENCL RECIPIENT ID CODE/NAME COLBURNFT S

E C

NRR/DE/EELB NRR/DRCH/HHFB NRR/DRCH/HOLB NRR/DRPM/PECB NRR/DSSA/SRXB RGN4 FILE 01 LITCO BRYCEFJ H

NOAC QUEENER,DS NUDOCS FULL TXT COPIES LTTR ENCL 2

1 1

1 1

1 1

NOTE TO A' "RIDS" RECZPZENTS:

PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEZVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD)

ON EXTENSION 415-2083 TOTAL NUMBER OF COPIES REQUIRED:

LTTR 25 ENCL

WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968

~ Richland, Washington 99352-0968 April9, 1997 G02-97-068 Docket No. 50-397 Mr. E.W. Merschoff NRC Regional Administrator U.S. NRC, Region IV 611 Ryan Plaza Drive Arlington, Texas 76011-8064 Gentlemen:

Subject:

WNP-2, OPERATING LICENSE NPF-21 EVALUATIONOF MARCH27, 1997 REACTOR SCRAM During testing of the Adjustable Speed Drive (ASD) control system on March 27, 1997 a planned trip of a single main feedwater pump was initiated from approximately 97% reactor power.

As expected, a runback of the two recirculation pump to approximately 27 hertz was observed as the ASD control system responded to the loss of one main feedwater pump condition.

Subsequently, an unplanned additional recirculation pump speed runback to approximately 15 hertz occurred, per design, when a cavitation interlock condition of less than 9.9 degrees Fahrenheit difference between the recirculation pump suction and reactor steam line existed for greater than 15 seconds.

The second recirculation pump speed reduction to 15 hertz resulted in the plant entering Region A of the power-to-flow map.

Although stable, non-oscillatory core power conditions were observed at all times during this transient, a manual reactor scram was inserted by control room personnel in accordance withTechnical Specification 3.4.1 requirements for entry into Region A.

Subsequent to the event, several discussions were held between Supply System personnel and NRC staff concerning the details of the testing and resultant manual reactor scram.

On April 3, 1997, during discussions with Region IV senior management, the Supply System committed to provide the results of an evaluation into the events surrounding the March 27, 1997, reactor scram.

The details of the evaluation, the conclusions

reached, and any corrective actions planned willbe shared with the NRC prior to plant startup from the spring 1997 maintenance and refueling outage.

Additional details of the planned Supply System activities are provided herein.

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Page 2 EVALVATIQNOF MARCH27, 1997 REACTOR SCRAM The Supply System evaluation willbe conducted by two separate evaluation teams.

An event evaluation team, composed primarilyofSupply System personnel, willinvestigate the event with the results and conclusions presented to plant management.

Additionally, a second independent evaluation team made up primarily of non-Supply System personnel will evaluate the event, including performing a critical review of the investigation conducted by the event evaluation team.

This independent evaluation team will provide the results of their review to Supply System senior management.

The results of both of these evaluations willbe made available to the NRC for review prior to restart ofWNP-2.

The specific areas to be evaluated by these teams are:

the analytical results of the testing performed on March 27, 1997 the performance of the on-shift operations personnel leading up to, during, and immediately following the manual reactor scram on March 27, 1997 the performance of the ASD and digital feedwater systems during the testing on March 27, 1997 the adequacy ofthe design integration for installation of the reactor power uprate, ASD, and digital feedwater modifications the adequacy of the ASD and digital feedwater test pmcedure as it relates to the conditions, surrounding the reactor scram on March 27, 1997.

The overriding purpose of the above defined reviews is to ensure the Supply System has a thorough understanding of the events surrounding the March 27, 1997, reactor scram, and through this understanding development of any needed corrective actions.

The schedule for implementation of any identified corrective actions will be based on the significance of the findings and importance to plant safety. In addition, several modifications to the ASD logic are planned to improve the system performance.

The results ofthe evaluations described above will be factored into the development of the planned modifications to determine what, if any, additional plant testing is required or desirable.

The schedule for completion of the above activities is as follows:

event evaluation team completion - May 9, 1997 independent evaluation team completion - May 16, 1997.

Page 3 EVALUATIONOF MARCH27, 1997 REACTOR SCRAM In order to provide the NRC with, an adequate opportunity to evaluate the details of the event and the conclusions reached by the Supply System prior to a joint meeting, the Supply System proposes,a meeting during either the week of May 27 or the week of June 2, 1997.

This meeting willallow a critical exchange of information, questions, and ideas prior to the planned completion of the WNP-2 maintenance and refueling outage on June 17, 1997.

Should you have any questions or desire additional information on this matter please contact me or D. A. Swank at (509) 377-4563.

Respec

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.V. Panish Chief Executive Officer MailDrop 1023 DAS/lm CC:

, KE Perkins, Jr. - NRC RIV, Walnut Creek Field Office TG Colburn - NRR NRC Sr. Resident Inspector - 927N DL Williams - BPA/399 PD Robinson - Winston &Strawn Document Control Desk - NRC