ML20140E918

Safety Evaluation Supporting Amend 133 to License DPR-43

ML20140E918
Person / Time
Site:	Kewaunee
Issue date:	06/07/1997
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20140E890	List: ML20140E886 ML20140E900 ML20140E918
References
NUDOCS 9706120247
Download: ML20140E918 (3)

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,s p n a u p *1 UNITED STATES

. g j NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 2066f4001 o

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATING TO AMENDMENT NO. 133 TO FACILITY OPERATING LICENSE NO. DPR-43 l

WISCONSIN PUBLIC SERVICE CORPORATION WISCONSIN POWER AND LIGHT COMPANY MADIS0N GAS AND ELECTRIC COMPANY KEWAUNEE NUCLEAR POWER PLANT DOCKET NO. 50-305

1.0 INTRODUCTION

l By letter dated April 28, 1997, as supplemented on May 19, 1997, Wisconsin Public Service Corporation (WPSC), the licensee, requested a revision to the ,

Kewaunee Nuclear Power Plant (KNPP) Technical Specifications (TSs). The l proposed amendment would establish a new design basis flow rate for the auxiliary feedwater (AFW) pumps consistent with the assumptions used in the reanalysis of the limiting design basis event for the AFW system. The Basis for TS 3.4.b, " Auxiliary Feedwater System," would be revised to reflect the change in AFW flow and to clarify the requirements.for the AFW cross-connect l valves.

The May 19, 1997, submittal provided clarifying information that did not change the initial proposed no significant hazards consideration determination ,

published in the Federal Reaister on May 7, 1997 (62 FR 24977).

2.0 EVALUATION During a safety system operational inspection (SS0PI) conducted at KNPP in January 1997, NRC inspectors identified a concern with the AFW pumps not-achieving the flow values assumed in the current safety analyses of record.

The current KNPP Updated Safety Analysis Report (USAR), Section 6.6, describes I the two motor-driven and one turbine-driven AFW pumps as each having a capacity of 240 gpm with up to 40 gpm of the 240 gpm providing continuous recirculation. The same section of the USAR also states that "the feedwater flow rate required to prevent thermal cycling of the tube sheet and for removing residual heat is the same, about 160 gpm for the reactor (or 80 gpm l per steam generator). A 200 gpm flow to the steam generators is, therefore, l sufficient to fulfil the above functions." The Basis for TS 3.4.b also contains these same words. The concerns raised during the SS0PI was that the

. AFW pumps could not deliver 200 gpm to the steam generators (SGs) as designed.

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In response to the staff concerns, the licensee, .in its April 28 and May 19,

1997, submittals, stated that a new design basis AFW flow rate of 176 gpm had been established. To support this minimum AFW flow rate, the licensee completed a reanalysis of the limiting design basis accidents and transients involving the AFW system. The licensee concluded that changing the AFW flow rate will not affect the consequences of the most limiting transients; (1) loss of load with respect to peak system pressure, and (2) uncontrolled rod withdrawal with respect to minimum departure from nucleate boiling ratio (MONBR). Changing the AFW flow rate will not impact these transients since, in the time frame of interest for the safety analysis, the AFW system is not operating following these events.

The loss of feedwater transient, however, is affected by the change in AFW l flow rate. The licensee performed a retnalysis of this event assuming AFW  !

flow of 176 gpm delivered to SGs and the results of the reanalysis I demonstrated that all acceptance criteria for this event are met. - The licensee stated that the small break loss of coolant accident (LOCA) has been previously analyzed assuming 176 gpm AFW flow rate with the results meeting the acceptance criteria of 10 CFR 50, Appendix K. The licensee has also evaluate; the impact of the AFW flow change on other licensing basis analysis, including Appendix R design requirements, Station Blackout, and anticipated transient without scram (ATWS). The relevant acceptance criteria continue to be satisfied for these analyses. l To clarify the design basis AFW flow rate of 176 gpm at Kewaunee, the licensee proposed the following:

1) The Basis for TS 3.4.b would be modified to remove the explicit values of required AFW flow and pump capacities. A general statement would be '

added to indicate that each AFW pump has 100% of the required capacity assumed in the accident analysis.

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2) The USAR would be updated to document the safety analyses performed to support the minimum AFW flow rate of 176 gpm. The USAR will also be revised to clarify references to AFW flow and to reflect a pump capability of 216 gpm (176 gpm + 40 gpm recirculation flow) and accident analysis assumptions of 176 gpm AFW flow to the SGs.

3) The acceptance criteria for inservice testing (IST) performed per TS 4.2.a.2 would be revised to assure that the AFW pumps are capable of delivering the minimum required flow to the SGs under the plant conditions assumed in the safety analysis.

4) The Basis for TS 3.4.b would also be revised to clarify the restrictions for the operation of the AFW cross connect valves during plant power -

operation.

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The staff has reviewed the licensee's . submittal and finds that the reanalysis of minimum AFW flow is reasonably conservative and, therefore, acceptable.

l The staff also finds that the proposed TS and USAR changes accurately I l incorporate the results of the AFW flow reanalysis and are, therefore, I

acceptable.

3.0 STATE CONSULTATION

In accordance with the Commission's regulations, the Wisconsin State official was notified of the proposed issuance of the amendnent. The State official had no comments.

14 . 0 ENVIRONMENTAL CONSIDERATION This amendment involves a change to a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 or changes a surveillance requirement. The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluent that may be released offsite and that there is no significant increase in individual or ,

cumulative occupational radiation exposure. The Commission has previously l issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding )

(62 FR 24977). Accordingly, this amendment meets the eligibility criteria for l categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR I 51.22(b), no environmental impact statement or environmental assessment need  !

be prepared in connection with the issuance of this amendment.

5.0 CONCLUSION

The staff has concluded, based on the considerations discussed above, that:

(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner; (2) such activities will be conducted in compliance with the Commission's regulations; and (3) the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributors: C. Liang W. LeFave l

Date: June 7, 1997 I

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