ML071970358

RAI, Request to Modify UFSAR Related to Internal Flooding Design Basis

ML071970358
Person / Time
Site:	Kewaunee
Issue date:	08/02/2007
From:	Milano P NRC/NRR/ADRO/DORL/LPLIII-1
To:	Christian D Dominion Energy Kewaunee
Chernoff M, NRR/DORL, 415-4041
References
TAC MD0511
Download: ML071970358 (5)

Text

August 2, 2007Mr. David A. ChristianSenior Vice President and Chief Nuclear Officer Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711

SUBJECT:

KEWAUNEE POWER STATION - REQUEST FOR ADDITIONALINFORMATION RELATED TO INTERNAL FLOODING DESIGN-BASIS (TAC NO. MD0511)

Dear Mr. Christian:

By letter to the Nuclear Regulatory Commission (NRC) dated March 17, 2006, Dominion EnergyKewaunee, Inc. (DEK), submitted a request to modify the Kewaunee Power Station Updated Final Safety Analysis Report to add new design criteria associated with internal flooding analyses (License Amendment Request No. 215). By letter dated April 17, 2007, DEK provided a response to an NRC request for additional information (RAI) dated November 17, 2006.The NRC staff is reviewing your submittals and has determined that additional information isrequired to complete the review. The specific information requested is addressed in the enclosure to this letter. The NRC staff has discussed the enclosed RAI with Mr. Dave Sommers and other members of your staff. Subsequently, your staff indicated that a response to this RAI would be submitted within 45 days of receipt of this letter. If circumstances result in the need to revise the requested response date, please contact me at(301) 415-4041.Sincerely,/RA/Patrick D. Milano, Senior Project Manager Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor RegulationDocket No. 50-305

Enclosure:

Request for Additional Informationcc w/encl: See next page

ML071970358OFFICELPL3-1/PMLPL3-1/LADSS/SBPBDE/EMCBLPL3-1/BC(A)NAMEPMilanoTHarrisSGardocki for JSegalaKManolyTTateDATE08/02/0708/02/0707/24/0707/25/0708/2/07 Kewaunee Power Station cc:

Resident Inspectors OfficeU.S. Nuclear Regulatory Commission N490 Hwy 42 Kewaunee, WI 54216-9510Regional Administrator, Region IIIU.S. Nuclear Regulatory Commission Suite 210 2443 Warrenville Road Lisle, IL 60532-4351Ms. Leslie N. HartzDominion Energy Kewaunee, Inc.

Kewaunee Power Station N 490 Highway 42 Kewaunee, WI 54216Mr. Chris L. FunderburkDirector, Nuclear Licensing and Operations Support Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711Mr. Thomas L. BreeneDominon Energy Kewaunee, Inc.

Kewaunee Power Station N490 Highway 42 Kewaunee, WI 54216Ms. Lillian M. Cuoco, Esq.Senior Counsel Dominion Resources Services, Inc.

Millstone Power Station Building 475, 5th Floor Rope Ferry Road Waterford, CT 06385 ENCLOSUREREQUEST FOR ADDITIONAL INFORMATIONKEWAUNEE POWER STATIONDOCKET NO. 50-305In reviewing the Dominion Energy Kewaunee, Inc.'s submittals dated March 17, 2006, and April 17, 2007, related to internal flooding analyses for the Kewaunee Power Station, the Nuclear Regulatory Commission (NRC) staff has determined that the following information is needed in order to complete its review:1.Since any non Category I (seismic) equipment may break during an safe shutdownearthquake (SSE), is this considered in the flooding analysis? Please explain the basis.2.Why are Class II and III* structures, sy stems and components (SSC), which aredesigned to withstand Uniform Building Code loads, not to be considered as a potential flooding source? Provide the percentage of Class II, III and III* piping systems, whosefailure could impact the function of safety-related equipment, that have been evaluated for design-basis earthquake (DBE) loads.3.Item (d) in Section B.11.2 specifies operator actions. Please provide more specificcriteria for defining operator actions. For example, please provide information regarding the criteria for evaluating operator actions as described in American National Standards Institute/American Nuclear Society 58.8, "Time Response Design Criteria for Safety Related Operator Actions." 4.The application states that specific evaluations for the Class II and III piping insafeguard alley and the auxiliary building, are capable of withstanding the effects of a DBE without failure. Discuss these evaluations. Does this mean that all pipe/tanks in these areas will remain intact after an SSE? 5.Please discuss the use of the Section III Code for evaluation for level D loading andAmerican Society of Mechanical EngineersSection III, Appendix F. Provide the loadcombinations and stress allowable equations that were used to evaluate Class II, III andIII* piping systems for DBE loads. 6.Please explain why the Itemized Flood Guidelines sent to licensees in early 1970's arenot included in the Flooding Design Criteria.7.Please clarify whether your proposed internal flooding evaluation criteria will apply(1) only in the analysis of ruptures caused by seismic events, or (2) in the analysis of ruptures caused by any unspecified mechanism (e.g., seismic, random, corrosion, etc.). 8.The NRC staff has identified the following two examples where postulated failures ofseismically-qualified piping systems had been discussed with respect to flooding effects: A. By letter dated November 7, 1972, Kewaunee responded to an oral NRC staffrequest to address random pipe breaks in systems containing high-energy fluids.

Sections I through III of the enclosure to that letter provided analyses ofpostulated breaks in the main steam and main feedwater piping within the auxiliary building, and Section IV of that enclosure described analyses of miscellaneous piping systems. The analyses of miscellaneous piping systemsincluded evaluations of potential flooding effects from failures of the service water, component cooling, demineralized water, reactor makeup water system, waste disposal and spent fuel pool cooling. For these evaluations, the licensee determined that either the system has too low a volume to endanger engineered safety features or the rate of rise of water level was low enough to allow operator action before affecting safeguards equipment. B. In a letter to Wisconsin Public Service Corporation from the Atomic EnergyCommission (AEC) staff dated September 23, 1971, the AEC staff asked a question (Kewaunee Final Safety Analysis Report (FSAR) Question 8.16) regarding the potential failure of service water piping in proximity to the emergency diesel generator rooms. This question requested that Kewaunee provide an analysis of the effect of a rupture of one of the service water lines on the emergency power systems. The response to FSAR Question 8.16 was included with Amendment No. 13 to the Application for Construction Permit and Operating License for the Kewaunee Power Station, issued December 15, 1971.

The response stated that the rupture of a service water pipe in an emergency diesel generator room could result in loss of the generator or safeguards electrical bus in that room. In addition, the response stated that operation of service water valves from the control room would isolate the break and, if required, operators would realign service water supplies through intact piping. The proposed changes to the internal flooding evaluation criteria appear to focus on postulatedfailures of non-seismic piping and tanks. Please discuss how the above licensing basis information has been incorporated into the proposed evaluation criteria for internal flooding.