ML18107A416

Safety Evaluation Accepting Licensee Response to GL 96-06, Assurance of Equipment Operability & Containment Integrity During Design Basis Accident Conditions

ML18107A416
Person / Time
Site:	Salem
Issue date:	06/23/1999
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML18107A415	List: ML18107A414 ML18107A416
References
GL-96-06, GL-96-6, NUDOCS 9907070291
Download: ML18107A416 (3)

Text

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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555--0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION LICENSEE RESPONSE TO GENERIC LETTER 96-06, \\~ASSURANCE OF EQUIPMENT OPERABILITY AND CONTAINMENT INTEGRITY DURING DESIGN BASIS ACCIDENT CONDITIONS" SALEM GENERATING STATION. UNIT NOS. 1 AND 2 DOCKET NUMBERS 50-272 AND 50-311

1.0 INTRODUCTION

On September 30, 1996, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 96-06, "Assurance of Equipment Operability and Containment Integrity During Design Basis Accident Conditions," to request that licensees take certain actions to evaluate (1) piping systems that penetrate containment for potential overpressurization due to heatup and expansion of fluid during normal operation and accident conditions and (2) cooling water systems that serve containment air coolers to assure that these components are not vulnerable to waterhammer and two-phase flow conditions during accident conditions.

In a letter dated January 28, 1997, as supplemented on October 20, 1997, and May 8, 1998, the Public Service Electric and Gas Company (the licensee) provided its response to the NRC for the Salem Nuclear Generating Station, Unit Nos. 1 and 2, regarding thermally-induced pressurization of piping runs inside of containment. In a letter dated October 25, 1996, as supplemented by letters dated December 11, 1996, January 28, March 27, April 24, June 3, and June 12, 1997, the licensee responded to the waterhammer and two-phase flow issues in a proposed amendment to the Salem Units 1 and 2 Technical Specifications (TS). Although the amendment request was approved by the NRC staff on June 19, 1997, the staff requested additional information concerning post-modification testing, two-phase flow, and the station blackout (SBO) scenario in order to complete review of the GL response. In a letter dated October 15, 1998, the licensee provided this information.

2.0 EVALUATION 2.1 Thermally-Induced Overpressurization of Piping In its submittal of January 28, 1997, the licensee provided its screening criteria and identified fluid lines penetrating containment and potentially vulnerable to a water-solid volume subjected to an increase in pressure due to heating of trapped fluid. The licensee stated that it did not perform operability assessment of the affected penetrations on the basis that the Salem Generating Station, Unit 1, was shutdown and defueled, and the Salem Generating Station, Unit 2, was in Mode 5, Cold Shutdown, in which loss-of-coolant accident and main steam line 9907070291 990623 PDR ADOCK 05000272 P

PDR Enclosure

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... before the service water pumps are energized and waterhammer will not occur. If the service water pumps are energized before control air is restored, service water will be admitted to the containment fan coolers and waterhammer is likely to occur. The licensee does not expect this waterhammer to be very severe due to the presence of nitrogen gas in the voided service water lines. The licensee also expects that control air would be restored very soon after electrical power is available and, at that point, service water to the containment fan coolers would be automatically isolated. Therefore, no interruption of service water flow to the emergency diesel generators is anticipated for this scenario. The NRC staff is satisfied with the information provided and steps taken by the licensee to address the waterhammer and two-phase flow conditions.

3.0 CONCLUSION

On the basis of this evaluation, the NRC staff finds that the licensee has performed appropriate evaluations and corrective actions to resolve the issues of potential thermally-induced overpressurization of piping systems that penetrate containment and vulnerability of cooling water systems that serve containment air coolers to waterhammer and two-phase flow conditions during accident conditions. Therefore, the NRC staff concludes that the licensee has adequately addressed the requested actions discussed in GL 96-06.

Principal Contributor: B. P. Jain J. Tatum Date: June 30, 1999

H. The NRC staff has completed its review of the information provided by PSE&G and finds that it adequately addresses the actions requested in GL 96-06. The details of the staff's findings are detailed in the enclosed safety evaluation. Therefore, the NRC has closed TAC Nos. M96860 and M96861.

If you have any questions regarding this matter, please contact me at (301) 415-1457.

Docket Nos. 50-272 and 50-311

Enclosure:

Safety Evaluation cc w/encl: See next page Sincerely, ORIGINAL SIGNED BY:.

Patrick D. Milano, Senior Project Manager, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation DISTRIBUTION:

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