L-PI-07-101, LER 07-03-001 for Prairie Island, Unit 1 Regarding Unanalyzed Condition Due to Breached Fire Barrier

LER 07-03-001 for Prairie Island, Unit 1 Regarding Unanalyzed Condition Due to Breached Fire Barrier

ML080280407
Person / Time
Site:	Prairie Island
Issue date:	01/25/2008
From:	Wadley M Nuclear Management Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-PI-07-101 LER 07-03-001
Download: ML080280407 (5)

Text

Prairie Island Nuclear Generating Plant Operated by Nuclear Management Company, LLC January 25,2008 L-PI-07-101 10 CFR 50.73 U S Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant Units 1 and 2 Dockets 50-282 and 50-306 License Nos. DPR-42 and DPR-60 LER 1-07-03, Supplement I,Unanalvzed Condition due to Breached Fire Barrier

Reference:

1) LER 1-07-03, "Unanalyzed Condition due to Breached Fire Barrier,"

dated October 23,2007 (ADAMS Accession Number ML072960414).

Licensee Event Report (LER) 1-07-03, Supplement I , is enclosed. The LER supplement describes final cause evaluation conclusions and recommended corrective actions for a breached fire barrier that was identified. This event was previously reported on October 23, 2007, in Reference 1.

Summary of Commitments This letter contains no new commitments and closes the existing commitment from Reference 1 to supplement the LER.

Michael D. Wadley u Site Vice President, Prairie Island ~ u c l e aGenerating r Plant Nuclear Management Company, LLC Enclosure cc: Administrator, Region Ill, USNRC Project Manager, Prairie Island, USNRC Resident Inspector, Prairie Island, USNRC Department of Commerce, State of Minnesota 1717 Wakonade Drive East Welch, Minnesota 55089-9642 Telephone: 651.388.1121

ENCLOSURE LICENSEE EVENT REPORT 1-07-03, SUPPLEMENT 1 3 Pages Follow

Estimated burden per response to comply with this mandatory collection request: 50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br />.

Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the Records and FOlAlPrivacy LICENSEE EVENT REPORT (LER) Service Branch (T-5 F52), U.S. Nuclear Regulatory Commission, Washington. DC 20555-0001, or by internet e-mail to infocollects@nrc.gov, and to the Desk Officer, Oftice of Information and Regulatoly Affairs, NEOB-10202, (3150-0066), Office of Management and (See reverse for required number of Budget, Washington, DC 20503. If a means used to impose an information collection does ct below or in On August 9, 2007, Nuclear Management Company, LLC (NMC) staff documented an apparent breach between the Train A and Train B auxiliary feedwater pump rooms. The floor trench in the rooms is separated by a 12-inch thick concrete barrier. One of the penetrations in the barrier was a 4-inch pipe sleeve through which a 3-inch rubber hose has been run for several years. An evaluation of the as-found configuration determined on August 24, 2007, that the as-found configuration could have adversely affected the ability to safely shutdown in the event of a fire and NMC notified the NRC per 10 CFR 50.72(b)(3)(ii) as an unanalyzed condition. Thus, this event is being reported in accordance with 10 CFR 50.73(a)(2)(ii) as an unanalyzed The hose was removed and the fire barrier was restored (filled with fire-retardant wool and capped with A root cause evaluation concluded there were two root causes for the condition: (1) requirements for use of the auxiliary feedwater pump (AFWP) room trench and trench fire barrier pipe sleeve are not procedurally controlled, and (2) insufficient procedural direction, guidance, or criteria for evaluators to help them determine an appropriate threshold for issuing a new action request as a consequence of their evaluation findings.

I I

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (1-2001)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1) LER NUMBER (6) PAGE (3)

SEQUENTIAL REVISION YEAR Prairie Island Nuclear Generating Plant Unit 1 05000282 NUMBER NUMBER 2 of 3 07 -- 03 -- 1 -

TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

EVENT DESCRIPTION On August 9,2007, Nuclear Management Company, LLC (NMC) staff documented an apparent breach between the Prairie Island Nuclear Generating Plant (PINGP) Train A and Train B auxiliary feedwater' pump rooms. The floor trench in the rooms is separated by a 12-inch thick concrete barrier. One of the penetrations in the barrier was a 4-inch pipe sleeve through which a 3-inch rubber hose has been run for several years. An evaluation of the as-found configuration determined on August 24, 2007, that the as-found configuration could have adversely affected the ability to safely shutdown in the event of a fire.

EVENT ANALYSIS The as-found configuration was a breached fire barrier, such that the required degree of separation for redundant safe shutdown train was lacking, thus, this event is being reported in accordance with 10 CFR 50.73(a)(2)(ii) as an unanalyzed condition.

Impact on Safety System Functional Failure Performance Indicator No actual loss of function occurred as a result of the as-found condition. Consequently, this event is not reportable per 10CFR 50.73(a)(2)(v).

SAFETY SIGNIFICANCE This event did not result in a loss of function. In the event of a fire, it is possible that flammable liquids could have passed between rooms in the space between the hose and the pipe sleeve. The PINGP fire protection program requires compensatory measures be taken for missing or breached fire barriers (specifically, establish a fire patrol in the affected fire areas). A formal fire patrol had been established in the affected fire areas for other issues; of the several years the as-found configuration was in place, the only periods during which a formal fire patrol did not exist was from September 19, 2005, to December 12, 2005 and from December 22, 2005, to April 7, 2006 (with a brief exception during maintenance on January 18, 2006). Even though no formal fire patrol existed during the identified periods, a review of card reader logs indicates the fewest times the room was accessed on any day during this period was 15 times, which increases the likelihood any fire would have been detected prior to affecting redundant trains. Thus, this event did not affect the health and safety of the public and the safety significance of this event is considered minimal.

1 Ells System Identifier: BA

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (1-2001)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

CAUSE The root cause evaluation concluded there were two root causes for the condition: (1) requirements for use of the AFWP room trench and trench fire barrier pipe sleeve are not procedurally controlled, and (2) insufficient procedural direction, guidance, or criteria for evaluators to help them determine an appropriate threshold for issuing a new action request as a consequence of their evaluation findings.

CORRECTIVE ACTION The hose was removed and the fire barrier was restored (filled with fire-retardant wool and capped with threaded caps).

Corrective Actions identified by the root cause evaluation include procedure changes to:

prohibit the use of a hose in the AFWP room trench without an evaluation or temporary modification, and add guidance for criteria on when a new corrective action process action request is warranted during an apparent cause evaluation or condition evaluation.

PREVIOUS SIMILAR EVENTS Review of Licensee Event Reports for Unit 1 and Unit 2 since 2004 found no previous similar events where a fire barrier was found to have been breached without compensatory measures.