ML083170298

License Renewal - Request for Additional Information - Boral

ML083170298
Person / Time
Site:	Vogtle
Issue date:	11/18/2008
From:	Ashley D License Renewal Projects Branch 1
To:	Tynan T Southern Nuclear Operating Co
Ashley, D J, NRR/DLR/RPB1, 415-3191
References
Download: ML083170298 (6)

Text

November 18, 2008 Mr. Tom E. Tynan Vice President - Vogtle Southern Nuclear Operating Company, Inc.

7821 River Road Waynesboro, GA 30830

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2, LICENSE RENEWAL APPLICATION, SECTIONS 3.3 - BORAL

Dear Mr. Tynan:

By letter dated June 27, 2007, Southern Nuclear Operating Company, Inc., submitted an application pursuant to 10 CFR Part 54, to renew the operating licenses for Vogtle Electric Generating Plant, Units 1 and 2, for review by the U.S. Nuclear Regulatory Commission (NRC or the staff). The staff is reviewing the information contained in the license renewal application and has identified, in the enclosure, areas where additional information is needed to complete the review.

Items in the enclosure were discussed with Chalmer Meyer, and a mutually agreeable date for the response is within 30 days from the date of this letter. If you have any questions, please contact me at 301-415-3191 or e-mail Donnie.Ashley@nrc.gov.

Sincerely,

/RA/

Donnie J. Ashley, Sr. Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket Nos. 50-424 and 50-425

Enclosure:

As stated cc w/encl: See next page

ML083170298 OFFICE LA:DLR PM:RPB1:DLR BC:RPB1:DLR NAME IKing DAshley DPelton DATE 11/17 /08 11/18/08 11/18/08 VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION REQUEST FOR ADDITIONAL INFORMATION The staff has compared the information provided by the applicant related to the time limited aging analyses of reactor vessels of the Vogtle Electric Generating Plant (VEGP), Units 1 and 2, and the information provided in the licensees response to previous requests for additional information (RAIs). The staff has determined that some of the information provided, requires clarification or additional information.

Generic aging lessons learned recognizes the possibility of the existence of aging effects in the Boral used in the spent fuel storage racks and the need for having a plant specific aging management program. However, in the VEGP license renewal application (LRA),

Section 3.3.2.2.6, Reduction of Neutron-Absorbing Capacity and Loss of Material due to General Corrosion, the applicant has indicated that in VEGP, Unit 1, degradation of the Boral is insignificant and no aging management program is required. The applicant provided several justifications for not having a management program. In order to fully evaluate the justifications the staff requires the following additional information:

RAI-3.3-01 The staff is of the opinion that loss of material in Boral may impact the neutron absorption capability of the Boral panels used in the spent fuel storage rack designs.

a. Justify why reduction of neutron absorption capability has not been identified as an aging effect requiring management (AERM) for the Boral materials used in the design of the VEGP, Unit 1, spent fuel pool storage racks, particularly when loss of material has been identified as an AERM for this material.

b. Please explain, from your letter dated February 8, 2008 (ML080430373), how the core itself is considered to be suitable for exposure to borated water. If this is the case, then the aluminum from the core would be exposed to borated water, be able to oxidize, and release aluminum oxide to the spent fuel pool. If enough aluminum oxide from the core is released, how would this compromise the boron-carbide in the matrix and affect neutron absorbing capability? Could enough aluminum be released over the period of extended operation (approximately 70 year Boral life for the oldest Boral panels) to affect neutron absorbing capability?

c. Justify why a one-time inspection of the Boral material has not been credited and coupled to the Water Chemistry Program, in order to confirm that the Water Chemistry Program is effective in managing potential loss of material, and possibly reduction of neutron absorption capability, in the Boral panels.

RAI-3.3-02 Please describe how the neutron-absorbing capacity will be monitored. Please include a description of the parameters, calculations, and acceptance criteria. If degradation of Boral is identified, what mitigation strategies will be employed?

RAI-3.3-03 Please provide the following specifications of the Boral panels in the spent fuel pool racks:

a. Geometry of the Boral panels

b. Acceptance criterion for the areal density of boron.In previous letters to the Nuclear Regulatory Commission (NRC) dated May 3, 2005 (ML051260207) and July 7, 2005 (ML051940421), the licensee has stated that it did not have a Boral Surveillance program and that Southern Nuclear Company (SNC) continues to monitor the internal operating experience at one of its other plants that has a Boral Surveillance program.

Please identify the plant whose Boral Surveillance program is being monitored by SNC for VEGP, Unit 1, and if this plants Boral Surveillance program will be monitored into VEGP Unit 1s period of extended operation, please address the following:

c. Indicate the installation date of the Boral panels/racks in the monitored plant.

d. Describe the comparability of the monitored plants and VEGP, Unit 1s, spent fuel pool and Boral panels/racks.

e. Please confirm that the monitored plant has sufficient Boral coupon samples to maintain the sampling frequency through VEGP Unit 1s period of extended operation.

f. Please provide a detailed description of the Boral coupons and the tests performed on them during their examination:

1. What was the location of coupons relative to the spent fuel racks?

2. How were the coupons mounted and are they fully exposed to the spent fuel pool water?

3. What specific testing procedures are used for determining B-10 areal density, verifying surface corrosion (if any) and examining for blister formation?

4. After removal from the pool for inspection were the coupons inserted back at the same locations in the pool?

g. Please discuss the correlation between measurements of the physical properties of Boral coupons and the integrity of the Boral panels in the storage racks.

h. What was the subcritical margin used in the criticality analysis? How does this acceptance criteria account for potential degradation between surveillance periods?

i.

Please describe the corrective actions that would be implemented if coupon test results are not acceptable.

j.

Discuss the schedule for coupon removal and testing during VEGP, Unit 1s, period of extended operation to demonstrate continued Boral performance.

RAI-3.3-04 The age of the oldest Boral material in VEGP Unit 1s spent fuel pool is potentially already over 30 years old. Please explain which industry and plant specific operating experience would be applicable to Boral of this age.

RAI-3.3-05 In September 2003, inspection of Boral test coupons at Seabrook Nuclear Station revealed bulging and blistering of the aluminum cladding. Please discuss the impact, if any, that this event is considered to have on the surveillance of Boral at VEGP, Unit 1. Industry

experience has indicated that during longer exposure such blisters may form. Since formation of blisters may affect the efficiency of the Boral panels to attenuate neutrons (through flux trap formation) and may cause deformation of the fuel cells, the applicant should explain why blistering of the Boral panels will not be a safety concern in its plant.

RAI-3.3-06 Please discuss any other operating experience that may be applicable to VEGP and describe why it would not be a safety concern.

RAI-3.3-07 VEGP, Unit 2, has Boraflex that they no longer credit for criticality in their spent fuel pools.

There is no indication whether or not they still monitor the Boraflex for degradation. Past operating experience indicates that there can be blistering and bulging of the Boraflex material and the cladding surrounding the material. This can cause potential safety issues with fuel handling.

Although Boraflex is not credited for criticality in the VEGP, Unit 2, spent fuel pools, degradation of the material may impede safe handling of the spent fuel if blistering and/or bulging of the rack occurs. How will potential degradation of Boraflex material be identified and monitored during the proposed period of extended operation?

Letter to T. Tynan from D. Ashley, dated November 18, 2008 DISTRIBUTION:

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2, LICENSE RENEWAL APPLICATION, SECTIONS 3.3 - BORAL HARD COPY:

DLR RF E-MAIL:

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Vogtle Electric Generating Plant, Units 1 and 2 cc:

Mr. Tom E. Tynan Vice President - Vogtle Vogtle Electric Generating Plant 7821 River Road Waynesboro, GA 30830 Mr. N. J. Stringfellow Manager, Licensing Southern Nuclear Operating Company, Inc.

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

P.O. Box 1295 Birmingham, AL 35201-1295 Mr. 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 Street, SW Atlanta, GA 30334 Mr. Harold Reheis, Director Department of Natural Resources 205 Butler Street, SE, Suite 1252 Atlanta, GA 30334 Attorney General Law Department 132 Judicial Building Atlanta, GA 30334 Mr. Laurence Bergen Oglethorpe Power Corporation 2100 East Exchange Place P.O. Box 1349 Tucker, GA 30085-1349 Arthur H. Domby, Esquire Troutman Sanders Nations Bank Plaza 600 Peachtree Street, NE Suite 5200 Atlanta, GA 30308-2216 Resident Inspector Vogtle Plant 8805 River Road Waynesboro, GA 30830 Office of the County Commissioner Burke County Commission Waynesboro, GA 30830 Mr. Stanford M. Blanton, Esq.

Balch & Bingham, LLP P.O. Box 306 Birmingham, AL 35201 Ms. Monica M. Caston Vice President and General Counsel Southern Nuclear Operating Company, Inc.

40 Inverness Center Parkway P.O. Box 1295 Birmingham, AL 35201-1295 Chalmer R. Myer Southern Nuclear Operating Company, Inc.

40 Inverness Center Parkway P.O. Box 1295 Birmingham, AL 35201-1295