ML031080563

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Memo from William Beckner to Joseph Holonich, Regarding INES Level 2 Point Beach Event
ML031080563
Person / Time
Site: Point Beach  NextEra Energy icon.png
Issue date: 04/15/2003
From: Beckner W
NRC/NRR/DRIP/RORP
To: Joseph Holonich
NRC/NSIR/DIRO
References
FOIA/PA-2003-0094
Download: ML031080563 (5)


Text

$-, I D- L MEMORANDUM TO: Joseph J. Holonich, Deputy Director Division of Incident Response Operations Office of Nuclear Security and Incident Response FROM: William D. Beckner, Program Director Operating Reactor Improvements Program Division of Regulatory Improvement Programs Office of Nuclear Reactor Regulation SUBJ ECT: INES Level 2 Point Beach Event This memorandum transmits the Event Rating Form (ERF) for an event which occurred at the Point Beach Nuclear Facility. The event was rated as an International Nuclear Event Scale (INES) Level 2.

Attachment:

Event Review Form (ERF) cc w/attachment:

T. Reis W. Beckner D. Matthews R. Borchardt J. Holonich CONTACT:

J. Dozier NRR/DRIP/RORP/OES 301-415-1014

  • See previous concurrence DOCUMENT NAME: G:\RORP\OES\StaffFolders\Dozier\PointBeachl NES2.wpd OFFICE RSE:OES:RORP SC:OES:RORP RA:RIII PD:RORP D:DRIP AD:ADIP NAME l JDozier TReis JEDyer IWDBeckner DBMatthews RWBorchardt DATE 07/11 /2002 07/11/2002 07/ /2002 07/11/2002 07/ /2002 07/ /2002 EVENT RATING FORM (ERF)

THE INTERNATIONAL NUCLEAR EVENT SCALE (INES)

EVENT TITLE EVENT DATE Potential Common Cause Failure of Auxiliary Feedwater 200 1 .1 1 .29 RATING RATING OUT OF DEVIATION INCIDENT ACCIDENT FACILITY TYPE PROVISIONAL FINAL

  • DATE 2002.07.1 SCALE D U 0

1 0

2 1 1 1Reactor 3

_ _ _l 4 5 6 7 Power Reactor ERadwaste Facility

[l Research Radiation Source g COUNTRY FACILITY NAME Irradiation O Transportation b United States of America Point Beach, Nuclear Management Fuel Fabrication Ea Fuel D Co., United States of America Reprocessing LOCATION Research Facility D Mining/Milling D Two Rivers, Wisconsin Enrichment D Other D

_____________________________ Fcility OFF-SITE IMPACT YES NO RELEASE BEYOND AUTHORIZED LIMITS [1 U OVEREXPOSURE OF MEMBERS OF PUBLIC El ON-SITE IMPACT CONTAMINATION SPREAD O U WORKER OVEREXPOSURE E U DAMAGE TO RADIOLOGICAL BARRIERS El U DEGRADATION OF DEFENCE IN-DEPTH

  • E PERSON INJURED PHYSICALLY OR CASUALTY E U IS THERE A CONTINUING PROBLEM El E PRESS RELEASE ISSUED (IF YES, PLEASE ATTACH) El U EVENT DESCRIPTION On November 29, 2001, the licensee identified a potential common mode failure of the auxiliary feedwater (AFW) system upon a loss of instrument air. Specifically, a loss of instrument air would cause the AFW minimum flow recirculation valves to fail closed. At the time, there were no backup air or nitrogen accumulators associated with these specific valves. If the discharge or flow control valves for the AFW pumps had been throttled or closed while the minimum flow recirculation valves were also closed, the AFW pumps would have been placed in a condition of insufficient flow. This could have resulted in pump damage in a short interval of time. The licensee also identified that early in the post reactor trip emergency operating procedures, the operators were directed to control the AFW system flow without specific written guidance to maintain minimum AFW flow. The plant operators were directed to control flow to the steam generators to maintain desired level and to prevent overcooling of the reactor coolant system. The AFW minimum flow recirculation valves are air-operated. Without the short-term recovery of instrument air (within less than 10 minutes), the AFW minimum flow recirculation valves would fail closed potentially damaging the AFW pumps and causing the loss of secondary heat removal capability. There was no indication of recirculation flow

available to operators in the control room. Heat removal capability through primary system feed and bleed would also be adversely affected since instrument air is required to operate the pressurizer power-operated relief valves and nitrogen backup was not available. A loss of instrument air would cause a loss of normal feedwater and would initiate a dual-unit reactor trip.

In addition, other initiating events, e.g., fire, loss of off-site power, may have a similar vulnerability.

The licensee's corrective actions included prompt operator training, procedural changes to the emergency operating procedures, and the addition of back-up pneumatic supplies for the AFW pump minimum flow recirculation valves.

RATING JUSTIFICATION AND DIFFICULTIES ENCOUNTERED This event was rated in accordance with the INES User's Manual (2001 Edition). There were no off-site or on-site releases or consequences in this event. Also, no actual initiating events occurred. To obtain the INES rating, Section IV-3.2.1.3 (b) "Events without a real initiator" of the INES User's Manual was used. The initiating event was assumed to be a loss of instrument air (LOIA). LOIA causes a loss of secondary cooling capability if all AFW pumps are damaged due to insufficient flow.

Using Table IV of the INES User's manual, the operability of the degraded safety function (core cooling) was considered Adequate (C) because defense in depth provisions remain to perform the safety function. LOIA is judged to be an "Expected" initiating event. Therefore, the event rating for impact on defense in depth without an actual initiator is INES Level 2.

CONTACT PERSON FOR FURTHER INFORMATION NAME erry Dozier AFFILIATION US Nuclear Regulatory Commission ADDRESS PHONE (301) 415-1014 FAX I (301) 415-1032 l E-MAIL lxd@nrc.gov TO BE SENT TO THE IAEA INES COORDINATOR

  • FAX: + 43 1 2600 29723 IAEA,WAGRAMERSTRASSE 5, P.O. BOX, 100 A-1400 VIENNA, AUSTRIA
  • E-MAIL- D Delattre@IAEA.ORG Or D RUAlTT @IAEA ORG
  • PHONE: + 43 1 2600 26068 or 26079 In addition, the following should be added to the Related Documents area for the event:

Full Text of Document:

A COPY OF THIS LETTER AND ITS ENCLOSURES IS AVAILABLE ELECTRONICALLY FOR PUBLIC INSPECTION IN THE NRC PUBLIC DOCUMENT ROOM OR FROM THE PUBLICLY AVAILABLE RECORDS (PARS) COMPONENT OF THE NRC'S DOCUMENT SYSTEM (ADAMS). ADAMS IS ACCESSIBLE FROM THE NRC WEB SITE AT http://www.nrc.aov/reading-rm/adams.html (THE PUBLIC ELECTRONIC READING ROOM).

THE ADAMS ACCESSION NUMBER FOR THIS REPORT IS

Division of Regulatory Improvement Programs COVER PAGE DATE: December 24, 2002

  • ee ROUTING LIST *.*

NAME DATE

1. J. Dozier 07/ /02
2. T. Reis 07/ /02
3. W. Beckner 07/ /02
4. J. Dyer 07/ /02
5. D. Matthews 07/ /02
6. R. Borchardt 07/ /02
7. W. Beckner (Signature) 07/ /02
8. J. Dozier/E-mail to Holonich 07/ /02

-t DOCUM ENT NAME: G:\RORP\OES\StaffFolders\Dozier\PointBeachl NES2.wpd ADAMS ACCESSION NUMBER: ML DATE ENTERED: / /02 FORM 665 ATTACHED and filled out: YES NO