ML071220323

Request for Additional Information on the Proposed Amendment to Revise Fuel Storage Pool Boron Concentration

ML071220323
Person / Time
Site:	San Onofre
Issue date:	05/07/2007
From:	Kalyanam N NRC/NRR/ADRO/DORL/LPLIV
To:	Rosenblum R Southern California Edison Co
Kalyanam N, NRR/DORL/LP4, 415-1480
References
TAC MD1405, TAC MD1406
Download: ML071220323 (8)

Text

May 7, 2007 Mr. Richard M. Rosenblum Senior Vice President and Chief Nuclear Officer Southern California Edison Company San Onofre Nuclear Generating Station P.O. Box 128 San Clemente, CA 92674-0128

SUBJECT:

SAN ONOFRE NUCLEAR GENERATING STATION, UNITS 2 AND 3 -

REQUEST FOR ADDITIONAL INFORMATION ON THE PROPOSED AMENDMENT TO REVISE FUEL STORAGE POOL BORON CONCENTRATION (TAC NOS. MD1405 AND MD1406)

Dear Mr. Rosenblum:

By letter dated April 28, 2006 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML061220701), and as supplemented by letters dated November 13 and December 22, 2006 (ADAMS Accession Nos. ML063210425 and ML063610042, respectively), Southern California Edison (SCE) submitted an application to change the San Onofre Nuclear Generating Station, Units 2 and 3, technical specifications related to fuel storage pool boron concentration.

By letter dated April 12, 2007 (ADAMS Accession No. ML070950041), the Nuclear Regulatory Commission (NRC) staff sent a set of questions that required responses. From the subsequent telephone calls and review of the draft response from SCE, the NRC staff has determined that additional clarification and/or information, as requested in the enclosure, is needed to complete the review. We discussed this information with your staff by telephone and they agreed to provide the additional information within 30 days of the receipt of this letter.

If you have any questions, please contact me at (301) 415-1480.

Sincerely,

/RA/

N. Kalyanam, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-361 and 50-362

Enclosure:

Request for Additional Information cc: See next page

ML063210425 and ML063610042, respectively), Southern California Edison (SCE) submitted an application to change the San Onofre Nuclear Generating Station, Units 2 and 3, technical specifications related to fuel storage pool boron concentration.

By letter dated April 12, 2007 (ADAMS Accession No. ML070950041), the Nuclear Regulatory Commission (NRC) staff sent a set of questions that required responses. From the subsequent telephone calls and review of the draft response from SCE, the NRC staff has determined that additional clarification and/or information, as requested in the enclosure, is needed to complete the review. We discussed this information with your staff by telephone and they agreed to provide the additional information within 30 days of the receipt of this letter.

If you have any questions, please contact me at (301) 415-1480.

Sincerely,

/RA/

N. Kalyanam, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-361 and 50-362

Enclosure:

Request for Additional Information cc: See next page DISTRIBUTION:

PUBLIC RidsNrrDorl (CHaney/JLubinski) RidsNrrLAJBurkhardt LPLIV r/f RidsNrrDorlDpr RidsNrrPMNKalyanam RidsAcrsAcnwMailCenter RidsNrrDorlLpl4 (THiltz) RidsRgn4MailCenter (TPruett)

RidsOgcRp RidsNrrDssSpwb SSun, DSS ADAMS Accession No.: ML071220323 NRR-088 OFFICE NRR/LPL4/PM NRR/LPL4/LA NRR/DSS/SPWB NRR/LPL4/BC NAME NKalyanam:sp JBurkhardt GCranston THiltz DATE 5/4/07 5/4/07 5/7/07 5/7/07 San Onofre Nuclear Generating Station Units 2 and 3 cc:

Mr. Daniel P. Breig Director, Radiologic Health Branch Southern California Edison Company State Department of Health Services San Onofre Nuclear Generating Station P.O. Box 997414, MS 7610 P.O. Box 128 Sacramento, CA 95899-7414 San Clemente, CA 92674-0128 Resident Inspector/San Onofre NPS Mr. Douglas K. Porter, Esquire c/o U.S. Nuclear Regulatory Commission Southern California Edison Company Post Office Box 4329 2244 Walnut Grove Avenue San Clemente, CA 92674 Rosemead, CA 91770 Mayor Mr. David Spath, Chief City of San Clemente Division of Drinking Water and 100 Avenida Presidio Environmental Management San Clemente, CA 92672 P.O. Box 942732 Sacramento, CA 94234-7320 Mr. James T. Reilly Southern California Edison Company Chairman, Board of Supervisors San Onofre Nuclear Generating Station County of San Diego P.O. Box 128 1600 Pacific Highway, Room 335 San Clemente, CA 92674-0128 San Diego, CA 92101 Mr. James D. Boyd, Commissioner Mark L. Parsons California Energy Commission Deputy City Attorney 1516 Ninth Street (MS 31)

City of Riverside Sacramento, CA 95814 3900 Main Street Riverside, CA 92522 Mr. Ray Waldo, Vice President Southern California Edison Company Mr. Gary L. Nolff San Onofre Nuclear Generating Station Assistant Director - Resources P.O. Box 128 City of Riverside San Clemente, CA 92764-0128 3900 Main Street Riverside, CA 92522 Mr. Brian Katz Southern California Edison Company Regional Administrator, Region IV San Onofre Nuclear Generating Station U.S. Nuclear Regulatory Commission P.O. Box 128 611 Ryan Plaza Drive, Suite 400 San Clemente, CA 92764-0128 Arlington, TX 76011-8064 Mr. Steve Hsu Mr. Michael R. Olson Department of Health Services San Diego Gas & Electric Company Radiologic Health Branch 8315 Century Park Ct. CP21G MS 7610, P.O. Box 997414 San Diego, CA 92123-1548 Sacramento, CA 95899 March 2006

San Onofre Nuclear Generating Station Units 2 and 3 cc:

Mr. A. Edward Scherer Southern California Edison Company San Onofre Nuclear Generating Station P.O. Box 128 San Clemente, CA 92674-0128 March 2006

REQUEST FOR ADDITIONAL INFORMATION (RAI)

SAN ONOFRE NUCLEAR GENERATING STATION, UNITS 2 AND 3 (SONGS 2 AND 3)

SOUTHERN CALIFORNIA EDISON DOCKET NOS. 50-361 AND 50-362 REQUEST TO REVISE FUEL STORAGE POOL BORON CONCENTRATION The following questions are a continuation to those in our previous RAI letter dated April 12, 2007:

16. Followup RAI to Question 6 - Control Element Assemblies Lifetime Analysis Control Element Assemblies (CEAs) were credited in the criticality analysis. How long do you have to take this credit? How do you know that the neutron absorber (AgInCd) inventory in the CEAs is sufficient as this credit is needed?

The questions are also applied to the guide tube (GT) inserts with the neutron absorber of B-10. In addition, please confirm that the credit of GT inserts was previously approved by Nuclear Regulatory Commission (NRC) staff for the criticality analysis.

17. Section 4.5 of the criticality analysis report specifies the limitations for locations of fuel assemblies in the spent fuel pools (SFPs) to meet the reactivity requirements used in the criticality analysis. Discuss the control programs and plant procedures to assure that the worst fuel misloading case is limited to the single assembly misloading event, which is the worst design-basis event considered in the criticality analysis.

18. Use of CEAs In accordance with the Safety Evaluation (SE) for St Lucie-1 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML042670562), the bases for the NRC staff to accept the use of CEAs are:

(a) the licensee has demonstrated that it had appropriate controls, procedures, and analyses to both understand and preclude the phenomena including 1) cladding wear, 2) unrecoverable cladding strain, 3) irradiation assisted stress-corrosion cracking, and 4) absorber depletion, from affecting the SFP criticality analyses, and (b) the licensee has demonstrated that design and use of the removable CEAs proposed in St Lucie 1 satisfied the guidance in Section 5.1 (a and c only) of Regulatory Guide 1.13, "Spent Fuel Storage Facility Design Basis."

SONGS 2 and 3 is requested to provide information to demonstrate that it satisfies the SE conditions (a) and (b) listed above for St Lucie -1, and justify for any deviations.

19. Use of GT-Inserts In accordance with the SE for Millstone 2 (ADAMS Accession No. ML012850287), the bases for the NRC staff to accept the use of rodlets are:

(a) the rodlets were made from borated stainless steel, Type 304 B7, grade A with 2 weight percent of boron, manufactured in accordance with the requirements of standard ASTM A 887-89 and ASTM A 484-91; and (b) the licensee committed to implement a surveillance program where, at 5-year intervals, 1 percent of the rodlets will be visually inspected for any material degradation to assure that at all times there is enough poison material for reactivity control.

Please describe the material used in the SONGS 2 and 3 GT inserts and surveillance programs, and demonstrate that it satisfies the SE conditions (a) and (b) listed above for Millstone-2. Justification should be provided if the material of GT inserts and surveillance programs used at SONGS 2 and 3 are different.

20. Use of Erbium Rods Provide the ADAMS Accession No. for the SE approving the use of Erbium rods for pressurized-water reactor (PWR) licensing applications, and address how the applicable range and conditions specified in the SE are met for the application of Erbium rods in SONGS 2 and 3.

21. Please provide the explanation on the checkerboard pattern interface requirements described in Section 4.5.3 of Attachment L to your application dated April 28, 2006.

22. Based on the information on page 3 (item 7) and Figures 4-1 through 4-21 of Appendix L to the application dated April 28, 2006, it is clear that the effect of cooling time (Pu-241 decay) was included in the criticality analysis to determine the requirements for various assembly storage patterns proposed for storage in SFP.

Discuss the cooling effect, and describe how the effect was accounted for determining the burnup-enrichment requirements shown in Figures 4-1 through 4-21.

23. Proposed TS 3.7.17 requires that whenever any fuel assembly fuel is stored in the fuel storage pool, the fuel storage pool boron concentration shall be greater than or equal to 2,000 parts per million (ppm).

Item c of TS 4.3.1.1 requires that K-eff shall be less than or equal to 0.95 if full flooded with water borated to 1,700 ppm, which includes an allowance for uncertainty as described in Section 9.1 of the Updated Final Safety Analyses Report (UFSAR).

Clarify: (1) the contradictory requirements for boron concentration (2,000 ppm versus 1700 ppm) in the fuel storage pool; and (2) the specific pages in UFSAR Section 9.1 that contain the information related to an allowance indicated in item c of TS 4.3.1.1.21.

24. This question is regarding the draft RAI 11 response which provided a discussion of calculations of the axial burnup bias using SIMULATE-3.

The results of analyses in NUREG/CR-6801, "Recommendations for Addressing Axial Burnup in PWR Burnup Credit Analyses," indicated that the number of the nodes representing axial length of the fuel assemblies modeled in the computer codes would significantly affect the results of the axial burnup credit. Specifically, item 2 on page A-8 of NUREG/CR-6801 indicated that the 10 axial-zone model was inadequate for the axial burnup bias calculation. The results showed that a model with 18 or more axial zones could produce a reliable axial burnup bias.

In light of the NUREG/CR-6801 results, provide a discussion to show that the number of the axial-zone used in SIMULATE-3 is adequate and acceptable for the calculation of the axial burnup bias.