ML072680697

Request for Additional Information Regarding Alternate Source Term Application

ML072680697
Person / Time
Site:	Hatch
Issue date:	10/03/2007
From:	Martin R E NRC/NRR/ADRO/DORL/LPLII-1
To:	Madison D R Southern Nuclear Operating Co
Martin R E, NRR/DORL, 415-1493
References
TAC MD2934, TAC MD2935
Download: ML072680697 (5)

Text

October 3, 2007

Mr. Dennis R. Madison Vice President - Hatch Edwin I. Hatch Nuclear Plant 11028 Hatch Parkway North Baxley, GA 31513

SUBJECT:

EDWIN I. HATCH NUCLEAR PLANT, UNIT NOS. 1 AND 2 (HNP), REQUEST FOR ADDITIONAL INFORMATION (RAI) REGARDING ALTERNATE SOURCE TERM APPLICATION (TAC NOS. MD2934 AND MD2935)

Dear Mr. Madison:

By letter to the Nuclear Regulatory Commission dated August 29, 2006, Southern Nuclear Operating Company, Inc., proposed to revise the HNP licensing and design basis with a full scope implementation of an alternative source term. We have reviewed your application and have identified a need for additional information on certain seismic analyses as set forth in the Enclosure.

We discussed this issue with your staff on September 21, 2007. Your staff indicated that it plans to submit a response to this issue within sixty (60) days of receipt of this letter.

Sincerely,

/RA/ Robert E. Martin, Senior Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Docket Nos. 50-321 and 50-366

Enclosure:

RAI cc w/encl: See next page

- ML072680697 OFFICE NRR/LPL2-1/PM NRR/LPL2-1/LA NRR/EMCB/BC NRR/LPL2-1/BC NAME RMartin:nc MO'Brien KManoly EMarinos DATE 09/28/07 10/1/07 10/2/07 10/3/07 REQUEST FOR ADDITIONAL INFORMATION CONCERNING IMPLEMENTATION OF AN ALTERNATIVE SOURCE TERM APPLICATION FOR EDWIN I. HATCH NUCLEAR PLANT, UNIT NOS. 1 AND 2 (HNP)

1) It is stated on Page 19 of Enclosure 8 of the Southern Nuclear Operating Company (SNC) August 29, 2006, application that for 1/2 SME (Seismic Margin Earthquake) and operating loads, all four sets of cast-in-place anchor bolts at the condenser piers have capacities, based on Generic Implementation Procedure, Revision 2 (GIP-2) and the GIP supporting document on seismic verification of equipment anchorage, that are greater than their demand for all load combinations. Furthermore, based on the SNC letter dated July 16, 2007, Question 4, part 2, the maximum shear force is 281,000 pounds for the southeast pier. The resulting shear stress per bolt due to this force is slightly larger than the GIP-2 shear stress allowable considered in table C.3-1 for cast-in-place bolts. The Nuclear Regulatory Commission (NRC) staff requests the licensee to justify the exceedance. 2) It is stated on Page 13 of Enclosure 8 of the August 29, 2006, application, that the condenser sole plate has 1.5-inch thick by 50-inch long shear plates. The plan dimensions of the condenser piers are given as 58 inches x 38 inches in SNC's letter dated July 16, 2007, Question 4, part 3. There is an apparent inconsistency in this information with respect to whether there can be a 50-inch long shear lug on the narrow side. The NRC staff requests SNC to provide the configuration and dimensions of the shear lugs in the short direction and to revise Enclosure 8 appropriately. 3) Enclosure 8 does not include information relative to the evaluation and acceptability of the condenser sole plate shear lugs. The NRC staff requests SNC to demonstrate shear lug adequacy (e.g., weld stress, bending and shear stress in the shear lugs) and transfer of load from shear lug to the concrete pier (adequate bearing and shear strength of concrete). 4) With the presence of shear lugs on the underside of the condenser sole plate and considering the slotted hole details shown in Figure 6b of Enclosure 8, it appears that the anchor bolts may not be loaded in shear until yielding of the shear lugs occurs. The NRC staff requests the licensee to provide further information (assumed condenser base shear load path, etc.) relative to the rationale used to calculate the resulting shear force/stress in the anchor bolts as noted in Enclosure 8 and in the SNC letter dated July 16, 2007, Question 4, part 1. 5) There appears to be an inconsistency in the table provided in SNC's letter dated July 16, 2007, in response to Question 4, part 2. The axial force for the northeast pier, -172,000 pounds for the D + L - (1.25 x 1/2 SME) load combination is not consistent with -84,000 pounds for the D + L - 1/2 SME load combination. The NRC staff requests SNC to review the values in the referenced table and to revise the table accordingly. 6) Section 5.7 of the NRC safety evaluation report (dated March 3, 1999) for GE Topical Report NEDC-31858P, Revision 2, states. "The staff has determined that the generic methodology presented, coupled with the plant-specific analytical evaluations for the condenser structural members and their associated anchorages, would provide an acceptable method to verify the seismic adequacy of the condenser design." The NRC staff requests SNC to clarify the evaluation performed Enclosure for the condenser shell/structural members and to provide justification for their adequacy. 7) The NRC staff requests SNC to identify the edition of the design codes ( the American Concrete Institute (ACI), American Institute of Steel Construction (AISC),

etc.) used in the evaluation of Unit 1 turbine building and condenser for the main steam isolation valve alternate leakage treatment path (e.g., on page 19 of Enclosure 8, there is no edition of the ACI 318 code noted for condenser pier evaluation). 8) Normally, the turbine pedestal is a separate structure independent of the turbine building. Enclosure 8 does not specifically address the turbine pedestal adequacy.

The NRC staff requests SNC to address the turbine pedestal potential Seismic Category II/I concern. 9) Enclosure 9 references GIP Revision 3A while Enclosure 8 references GIP Revision 2. The NRC staff requests SNC to review the respective references for consistency and to revise the pertinent sections accordingly.

Edwin I. Hatch Nuclear Plant, Units 1 & 2 cc: Laurence Bergen Oglethorpe Power Corporation 2100 E. Exchange Place P.O. Box 1349 Tucker, GA 30085-1349 Mr. R. D. Baker Manager - Licensing Southern Nuclear Operating Company, Inc. P.O. Box 1295 Birmingham, AL 35201-1295 Resident Inspector Plant Hatch 11030 Hatch Parkway N. Baxley, GA 31531 Harold Reheis, Director Department of Natural Resources 205 Butler Street, SE., Suite 1252 Atlanta, GA 30334 Steven M. Jackson Senior Engineer - Power Supply Municipal Electric Authority of Georgia 1470 Riveredge Parkway, NW Atlanta, GA 30328-4684

Mr. Reece McAlister Executive Secretary Georgia Public Service Commission 244 Washington St., SW Atlanta, GA 30334

Arthur H. Domby, Esq. Troutman Sanders Nations Bank Plaza 600 Peachtree St, NE, Suite 5200 Atlanta, GA 30308-2216

Chairman Appling County Commissioners County Courthouse Baxley, GA 31513

Mr. Jeffrey T. Gasser Executive Vice President Southern Nuclear Operating Company, Inc. P.O. Box 1295 Birmingham, AL 35201-1295

General Manager Edwin I. Hatch Nuclear Plant Southern Nuclear Operating Company, Inc. U.S. Highway 1 North P.O. Box 2010 Baxley, GA 31515

Mr. K. Rosanski Resident Manager Oglethorpe Power Corporation Edwin I. Hatch Nuclear Plant P.O. Box 2010 Baxley, GA 31515