ML20210K607

Submits Withdrawal of Proposed License Amend Re Secondary Containment Isolation Description & Refueling Accident Analysis Results

ML20210K607
Person / Time
Site:	Cooper
Issue date:	08/02/1999
From:	Swailes J NEBRASKA PUBLIC POWER DISTRICT
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-91-18, GL-99-02, NLS990067, NUDOCS 9908060178
Download: ML20210K607 (4)

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n Nebraska Public Power District Nebraska's Energy Leader NLS990067 August 2,1999 U.S. Nuclear Regulatory Commission Attention: Document Control Desk

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Washington, D.C. 20555-0001 Gentlemen:

Subject:

Withdrawal of Proposed License Amendment Secondary Containment Isolation Description and Refueling Accident Analysis i

Results Cooper Nuclear Station, NRC Docket 50-298, DPR-46

Reference:

1. NPPD Letter NLS980122 from J. H. Swailes (NPPD) to USNRC, dated j

August 6,1998," Proposed License Amendment, Secondary Containment Isolation Description and Refueling Accident Analysis Results."

2. Safety Evaluation Report for Cooper Nuclear Station, February 14,1973.

3. NPPD Letter NLS950032 from J. H. Mueller (NPPD) to USNRC, dated January 19,1995, " Transmittal ofInformation in Support of Proposed Change No.135 to the CNS Technical Specifications."

4. Letter from James R. Hall (USNRC) to Mr. Guy R. Horn (NPPD) dated January 27,1995," Cooper Nuclear Station - Amendment No.167 to Facility Operating License No. DPR-46 (TAC No. M89770)."

5. Letter from James R. Hall (USNRC) to Mr. G. R. Horn (NPPD) dated August 19,1998," Request for Exigent License Amendment Related to Secondary Containment Isolation - Cooper Nuclear Station (TAC No. MA2464)."

In Reference 1, Nebraska Public Powcr District (District) submitted a request for Nuclear Regulatory Commission (NRC)' approval of an Unreviewed Safety Question (USQ) involving the g

Secondary Containment Isolation Description and Refueling Accident Analysis Results.

g 0, Specifically, the request documents the as-built condition of an air-operated damper ia series with a motor-operated damper in the two normal ventilation exhaust ducts of Secondary Containment credited with mitigating the consequences of a refueling accident. Considering a single failure of the air-operated damper, the secondary containment building isolation time increases from six seconds to approximately 90 seconds. This resulted in the discovery that, due Cooper Nudear Station f

FO. Box 98/ Brownelle, NE 68321-0098 Telephone: (ta?) s25 38n / fax: (402) B25 5211 9908060178 990802 ht10//www nppd com PDR ADOCK 05000298 P

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to the increased isolation time, the maximum theoretical release for the refueling accident was greater than that originally' evaluated by the NRC in Reference 2. Therefore, a USQ, requiring NRC approval, was determined to exist.

The request for NRC approval of this USQ included a statement that the as-built plant condition described in the USQ did not impact the refueling accident Control Room operator dose calculations (Reference 3) used in support of CNS Technical Specification Amendment 167, which allowed for increased flow capacity of the Control Room Emergency Filter System (Reference 4). The refueling accident calculations associated with CNS Technical Specification Amendment 167 had conservatively assumed the air-operated damper failure and thus a 90 second isolation time for the motor-operated damper following a refueling accident. In the Safety Evaluation that accompanied CNS Technical Specification Amendment 167 the refueling accident Control Room operator dose calculation was not specifically reviewed as part of the

' decision to issue Amendment 167 to the CNS Technical Specifications.

l l The District requested NRC review and approval of the subject USQ license amendment on an 3

exigent basis, based on the District's determination that the proposed amendment request required approval prior to the unrestricted movement of fuel. The NRC determined in Reference

" 5 that the proposed amendment request did not need to be treated as an exigent request based upon the guidance provided in Generic Letter 91-18, Revision 1, and that intrim operation of CNS would be governed by the_ processes of operability determination and corrective action of

' 10 CFR Part 50, Appendix B. Thus, the District conducted additional redesvs of the refueling accident calculations to enable refueling operations to be conducted under the provisions of these governing processes. During these reviews the District identified an inconsistency between the assumptions used for the refueling accident Control Room operator dose calculation, and the j

assumptions used for the refueling accident off-site dose calculation. Based on the results of

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these reviews, and using the guidance provided in Generic Letter 91-18, Revision 1, restrictions were placed on certain fuel handling activities. These restrictions currently remain in place.

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' The District, therefore, withdraws its request for NRC approval of the proposed license I

amendment submitted under Reference 1 due to the inconsistencies identified between the

- refueling accident Control Room operator dose and off-site dose calculations. As discussed with NRC CNS Project Manager on July 21,1999, the District has considered various resubmittal options associated with this issue, and the recently issued NRC Generic Letter regarding -

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Laboratory Testing of Nuclear-Grade Activated Charcoal (GL 99-02). In that there are flesign basis accident dose calculation revisions common to both of these issues, it is most appropriate to combine both issues into one submittal rather than two separate submittals. The District commits to resubmitting the proposed license amendment associated with the Secondary Containment Isolation Description and Refueling Accident Analysis Results USQ, integrated into the response to GL 99-02, by November 30,1999. In addition, this submittal will address i

1 NLS990067 August 2,1999 Page 3 of 4 differences between the District and NRC staff regarding the assumptions used for calculating doses to the control room operators following a postulated loss of coolant accident (Reference 4).

By copy of this letter the appropriate State of Nebraska official is being notified in accordance with 10 CFR 50.91 (b)(1). Copies to the NRC Region IV office and the CNS Resident Inspector are also being provided in accordance with 10 CFR 50.4 (b)(2).

Should you have any questions or require any additional information regarding this submittal, please contact Mr. Larry Newman at (402) 825-5551.

Sincerely, f

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3. S ai s

i Pr ident of Nuclear Energy

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cc: Regional Administrator USNRC - Region IV Senior Project Manager USNRC - NRR Project Directorate IV-1 Senior Resident Inspector USNRC Environmental Health Division - Program Manager Nebraska Department of Health NPO Distribution i

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, NLS990067 August 2,1999

. Page 4 of 4 STATE OF NEBRASKA )

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NEMAHA COUNTY

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John H. Swailes, being first duly sworn, deposes and says that he is an authorized representative cf the Nebraska Public Power District, a public corporation and political subdivision of the State l

of Nebraska; tha.. he is duly authorized to submit this correspondence on behalf of Nebraska f

Public Power District; and that the statements contained herein are true to the best of his i

knowledge and belief.

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ohrI H. Swailes bed i my presence and sworn to before me thisd dayof Aw$ttSt

,1999.

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NOTARY'PUBLIC i

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ATTACHMENT 3 LIST OF NRC COMMITMENTS l

Corfespondence No: NLS990067 The following table identifies those actions committed to by the District in this document. Any other actions discussed in the suamittal represent intended or

\\ planned actions by the District, They are described to the NRC for the NRC's information and are not regulatory commitments.

Please notify the NL&S Manager at Cooper Nuclear Station of any questions regarding this document or any associated regulatory commitments.

COMMITTED DATE COMMITMENT OR OUTAGE The District commits to resubmitting the proposed license amendment associated with the Secondary Containment Isolation Description and Refueling Accident Analysis Results USQ, integrated into the response to GL 99-02, by November 30, 1999.

In addition, this submittal will 11/30/99 address differences between the District and NRC staff regarding the assumptions used for calculating doses to the control room operators following a postulated loss of coolant accident.

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l PROCEDURE NUMB"R 0.42 l

REVISION NUMBER 6 l

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