ML20113H487

Part 21 Rept Re Surge Line Flooding Which May Occur When Large Pressurizer Vent Used to Support Reduced Rc Inventory Operations.Notification Received from Westinghouse on 920312.Item Not Reportable Per 10CFR21

ML20113H487
Person / Time
Site:	Kewaunee
Issue date:	07/30/1992
From:	Schrock C WISCONSIN PUBLIC SERVICE CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CON-NRC-92-100, REF-PT21-92 NUDOCS 9208040037
Download: ML20113H487 (2)

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NRC-92-100 WPSC l4141431 1 LOG .

TELLCOP ER (4141433 5544 iA$vufA (GED G93 Glic5EbiGideGc~srnvici}Q@ wo tmn em e o o re 1 ace . caen en m basannom July 30,1992 U. S. Nuclear Regulatory Commission A'ITN: Document Control Desk Washington, D.C. 2055$ Gentlemen: Docket 50-305 Operating License DPR-43 Kewuu.iec Nucicar Power Plant Siligtlitltfleo. ding

References:

1) Ixiter from C. A. Schrock (WPSC) to NRC Document Control Desk dated hiay 11,1992.

2) NRC wneric Letter 88-17, "less of Decay 11 eat Removal," dated October 17, 1988.

Wisconsin Publ' Service Corporation (WPSC) received noti 0 cation of a possible 10 CFR Pan 21 (part 21) defect from Westinghouse Electric Corporation on hlarch 12, 1992. The subject of the Westinghouse letter is a phenomenon tenned surge line flooding which may occur when a large pressurizer vent is used to suppon reduced reactor coolant inventory operations. Due to the complexity of this issue WPSC was not able to detennine if surge line flooding represented a substantial safety hazani within the 60 day period allowed for in pan 21. Therefore, an interim report was submitted (reference 1) in order to infonn the NRC of the actions WPSC was taking to detennine the safety significance of surge line Gooding. WPSC stated that Westinghouse was perfonning an analysis for WPSC to detennine the impact, if any, on the analyses that they performed for WPSC in response to Generic lxtter 88-17 (reference 2). This analysis has been perfonned and the results indicate that surge line Gooding can occur at the Kewaunee Nuclear Power Plant (KNPP)if core cooling is lost and boiling occurs. There are however, administrative controls that maintain physical barriers and a hot leg vent path which would prevent an inventory loss through a cold leg opening as described in the t 9200040037 920730 ADOCK 05000305 PDR S PDR , [j ,)t\ / g V

f e Docuinent Control Desk Jiily 30,1992 Page 2 Westinghouse potential part 21 letter Therefore, WPSC has detennined that this phenoinenon does not constitute a substantial safety hazard requiring pan 21 notification. As a result of the identification of this phenoinenon and the new Westinghouse analysis, WPSC will revise the operating procedures for reduced inventory conditions prior to the next scheduled refueling outage at the KNPP (htarch 1993). In addition, a coruplete evaluation of the ability of the steam generator nonle dams to serve as a hot leg to cold leg barrier during refueling conditions will be perfonned. In the interim, a copy of this letter and the new Westinghouse analysis will be routed to all operations personnel as required reading. If you have any questions please contact a member of my staff. Sincerely, e a.J<LA C. A. Schrock hianager - Nuclear Engineering Ph1P/jac cc - US NRC - Region III hir. Patrick Castleman, US NRC urmc.carnwr 7 i l I

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