ML081680150

Generic Letter 2008-01, Managing Gas Accumulation in Emergency Core Cooling, Decay Hear Removal, and Containment Spray Systems, Proposed Alternative Course of Action

ML081680150
Person / Time
Site:	Columbia
Issue date:	08/21/2008
From:	Lyon C NRC/NRR/ADRO/DORL/LPLIV
To:	Parrish J Energy Northwest
Lyon, C F, NRR/DLPM, 415-2296
References
GL-08-001, TAC MD7812
Download: ML081680150 (7)

Text

August 21, 2008

Mr. J. V. Parrish Chief Executive Officer Energy Northwest P.O. Box 968 (Mail Drop 1023)

Richland, WA 99352-0968

SUBJECT:

COLUMBIA GENERATING STATION - RE: GENERIC LETTER 2008-01, "MANAGING GAS ACCUMULATION IN EMERGENCY CORE COOLING, DECAY HEAT REMOVAL, AND CONTAINMENT SPRAY SYSTEMS,"

PROPOSED ALTERNATIVE COURSE OF ACTION (TAC NO. MD7812)

Dear Mr. Parrish:

On January 11, 2008, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" (Agencywide Documents Access and Management System (ADAMS) Accession No. ML072910759). The GL requested licensees to submit information to demonstrate that the emergency core cooling, decay heat removal, and containment spray systems (hereinafter referred to as the "subject systems") are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, operational, and testing control measures are in place for maintaining this compliance.

In accordance with Section 50.54(f) of Title 10 of the Code of Federal Regulations (10 CFR), GL 2008-01 required that each licensee submit the requested information within 9 months (hereinafter referred to as the "9-month submittal") of the date of the GL. The GL also stated that if a licensee cannot meet the requested 9-month response date, the licensee is required to provide a response within 3 months (hereinafter referred to as the "3-month submittal") of the date of the GL, describing the alternative course of action it proposes to take, including the basis for the acceptability of the proposed alternative course of action.

By letter dated April 10, 2008 (ADAMS Accession No. ML081080115), Energy Northwest (the licensee) submitted a 3-month response to GL 2008-01 for Columbia Generating Station (CGS).

The NRC staff assessment of the response for CGS is contained in the enclosure to this letter.

The NRC staff reviewed your proposed alternative course of action and the associated basis for acceptance and concluded that they are acceptable for CGS, with the exception of the clarifications and associated requests discussed in the enclosure. This letter allows the licensee to implement its proposed alternative course of action provided that implementation is consistent with the clarifications and associated requests discussed in the enclosure.

J.

If you have any questions regarding this matter, please contact me at 301-415-2296.

Sincerely, /RA/

Carl F. Lyon, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Docket No. 50-397

Enclosure:

As stated

cc w/encl: See next page

ML081680150 OFFICE NRR/LPL4/PM NRR/LPL4/LA PGCB/BC DSS/DD NRR/LPL4/BC(A) NRR/LPL4/PM NAME FLyon GLappert MMurphy JWermeil BSingal FLyon DATE 8/15/08 8/14/08 8/20/08 8/18/08 8/21/08 8/21/08 Columbia Generating Station (June 2008)

cc:

Chairman Energy Facility Site Evaluation Council P.O. Box 43172 Olympia, WA 98504-3172

Mr. Gregory V. Cullen Manager, Regulatory Programs Energy Northwest P.O. Box 968, Mail Drop PE20 Richland, WA 99352-0968

Chairman Benton County Board of Commissioners P.O. Box 190 Prosser, WA 99350-0190

Mr. William A. Horin, Esq.

Winston & Strawn 1700 K Street, N.W.

Washington, DC 20006-3817

Mr. Matt Steuerwalt Executive Policy Division Office of the Governor P.O. Box 43113 Olympia, WA 98504-3113

Ms. Lynn Albin Washington State Department of Health P.O. Box 7827 Olympia, WA 98504-7827

Technical Services Branch Chief FEMA Region X 130 - 228th Street, SW Bothell, WA 98021-9796

Mr. Mike Hammond Department of Homeland Security FEMA/REP 130 - 228th Street SW Bothell, WA 98021-9796

Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 612 E. Lamar Blvd., Suite 400 Arlington, TX 76011-4125

Senior Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 69 Richland, WA 99352-0069

Mr. Ken Niles Assistant Director Oregon Department of Energy 625 Marion Street NE Salem, OR 97301-3737

Special Hazards Program Manager Washington Emergency Management Div.

127 W. Clark Street Pasco, WA 99301

NRC STAFF ASSESSMENT OF 3-MONTH RESPONSE TO GENERIC LETTER 2008-01 COLUMBIA GENERATING STATION DOCKET NO. 50-397

Background

On January 11, 2008, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" (Agencywide Documents Access and Management System (ADAMS) Accession No. ML072910759). The GL requested licensees to submit information to demonstrate that the emergency core cooling, decay heat removal, and containment spray systems (hereinafter referred to as the "subject systems") are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, operational, and testing control measures are in place for maintaining this compliance.

Specifically, the GL requested licensees to provide: (1) a description of the results of evaluations that were performed in response to the GL; (2) a description of all corrective actions that the licensee determined were necessary; and (3) a statement regarding which corrective actions were completed, the schedule for completing the remaining corrective actions, and the basis for that schedule.

In accordance with Section 50.54(f) of Title 10 of the Code of Federal Regulations (10 CFR), GL 2008-01 required that each licensee submit the requested information within 9 months (hereinafter referred to as the "9-month submittal") of the date of the GL. The GL also stated that if a licensee cannot meet the requested 9-month response date, the licensee is required to provide a response within 3 months (hereinafter referred to as the "3-month submittal") of the date of the GL, describing the alternative course of action it proposes to take, including the basis for the acceptability of the proposed alternative course of action.

Licensee's Proposed Alternative Course of Action

By letter dated April 10, 2008 (ADAMS Accession No. ML081080115), Energy Northwest (the licensee) submitted a 3-month response to GL 2008-01 for Columbia Generating Station (CGS).

The licensee indicated in the attachment to its letter that CGS will not be able to provide the requested information in GL 2008-01 pertaining to plant modification corrective actions by the requested date of Oc tober 11, 2008, due to the inability to finish the emergency core cooling, residual heat removal, and containment spray system walkdowns. The system walkdowns will not be completed because of concerns of the high radiation exposure due to: (1) the need to erect scaffolding; (2) the restrictions on removal of insulation from piping; (3) the need to enter into high radiation areas; and (4) the restrictions on entering the primary containment during power operation. In its letter dated April 10, 2008, the licensee made the following commitments for completion of the GL response:

"Walkdowns that could not be accomplished prior to October 11, 2008 due to the need to erect scaffolding, the restrictions on removal of insulation from piping, the need to enter into high radiation areas, and the need for containment entries that cannot be accomplished during power operation will be completed prior to the end of the next scheduled refueling outage, currently scheduled for May-June 2009.

Any corrective actions requiring plant modifications identified as a result of the deferred walkdowns will be provided to the NRC staff within 90 days following completion of that refueling outage."

The licensee stated that the alternative course of action is acceptable based on the low risk of gas intrusion issues, which is based on the following:

Previous system evaluations to determine the adequacy of the current design basis have been completed in response to industry and NRC identified operating experience.

[CGS] surveillance data obtained over the past several years indicate that gas accumulation is not affecting operability of ECCS/RHR [emergency core cooling system/residual heat removal] pumps. Surveillances of these pumps include monitoring and trending of suction pressure, flow vs. differential pressure, vibration, and motor current. Inspections of pipe supports in accordance with the [CGS inservice inspection] program indicate that there were no unacceptable conditions of pipe supports related to the secondary effects of gas accumulation (i.e., water hammer).

No anomalies related to gas accumulation were identified during events in which HPCS

[high pressure core spray] actuated and injected water into the reactor vessel.

Detailed evaluations of as-built piping drawings are expected to be completed prior to

October 11, 2008 incl uding those portions of piping that will not have received in-plant walkdowns by that date. Areas of potential concern will be entered into the corrective action program and treated accordingly.

Detailed evaluations and, if necessary, revisions of site procedures which ensure the piping systems are sufficiently full of water to perform their functions are expected to be

completed prior to October 11, 2008 including those portions of piping that will not have received in-plant walkdowns by that date. Areas of potential concern will be entered into the corrective action program and treated accordingly.

NRC Staff Assessment

The NRC staff finds that, with the exception of the clarifications and associated requests discussed below, that the licensee's proposed alternative course of action is acceptable based on the above-described operating experience, testing, procedures and corrective actions associated with managing gas accumulation at CGS.

The NRC staff requests the licensee to submit the information requested in GL 2008-01 as follows:

(1) 9-Month Initial Submittal - For the portions of the subject systems that are accessible prior to the CGS spring 2009 refueling outage, provide all GL requested information to the NRC by October 11, 2008.

(2) 9-Month Supplemental (Post-Outage) Submittal - Except for the long-term items described below, provide all remaining GL requested information for the subject systems to the NRC within 90 days following startup from the CGS spring 2009 refueling outage.

For each of these two submittals (the 9-month initial and supplemental submittals), and consistent with the information requested in the GL, the licensee should provide: (1) a description of the results of evaluations that were performed in response to the GL; (2) a description of all corrective actions that the licensee determined were necessary; and (3) a statement regarding which corrective actions were completed, the schedule for completing the remaining corrective actions, and the basis for that schedule.

The NRC staff noted that the licensee's response letter dated April 10, 2008, did not mention other potential long-term actions that are identified in the GL. For instance, the industry is assessing whether it is necessary to perform pump testing to determine the allowable limits on ingested gas volume in pump suctions, as well as the need to develop an analysis capability to adequately predict void movement (entrapped gas) from piping on the suction side of the pumps

into the pumps. It is unlikely this industry effort will be complete fo r the 9-month initial or supplemental submittals. Further, technical specification changes may be necessary to reflect the improved understanding achieved during response to the GL, but these cannot be fully developed for the 9-month initial or supplemental submittals. A Technical Specifications Task Force traveler may provide a generic example that can be adopted by licensees. The NRC staff requests that the licensee address in its 9-month submittal how it plans to track such long-term actions (e.g., Corrective Action Program and/or commitment tracking). The NRC plans to perform follow up inspections of licensee responses to GL 2008-01 at all plants using a Temporary Instruction inspection procedure.

Principal Contributor: W. Lyon

Date: August 21, 2008