ML17284A354
| ML17284A354 | |
| Person / Time | |
|---|---|
| Site: | Hatch, Vogtle  |
| Issue date: | 11/07/2017 |
| From: | Markley M Plant Licensing Branch II |
| To: | Hutto J Southern Nuclear Operating Co |
| MOrenak, NRR/DORL/LPLII-1, 415-3229 | |
| References | |
| CAC MF9411, CAC MF9435, CAC MF9436, EPID L-RC-2016-0001 | |
| Download: ML17284A354 (6) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON_ DC 20555-0001 November 7, 2017 OMB Control No. 3150-0231 Mr. James J. Hutto Regulatory Affairs Director Southern Nuclear Operating Company, Inc.
P. 0. Box 1295, Bin - 038 Birmingham, AL 35201-1295
SUBJECT:
EDWIN I. HATCH NUCLEAR PLANT, UNITS 1 AND 2; AND VOGTLE ELECTRIC GENERATING PLANT, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION REGARDING GENERIC LETTER 2016-01, "MONITORING OF NEUTRON-ABSORBING MATERIALS IN SPENT FUEL POOLS" (CAC NOS.
MF9435, MF9436, AND MF9411; EPID L-RC-2016-0001)
Dear Mr. Hutto:
On April 7, 2016, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2016-01, "Monitoring of Neutron-Absorbing Materials in Spent Fuel Pools" (Agencywide Documents Access and Management System (ADAMS) Accession No. ML16097A169), to address the degradation of neutron-absorbing materials (NAMs) in wet storage systems for reactor fuel at power and non-power reactors.
Southern Nuclear Operating Company, Inc. (SNC, the licensee) submitted letters dated November 2, 2016 (ADAMS Accession Nos. ML16307A295 and ML16307A297), providing information in response to Generic Letter 2016-01.
To complete its review, the NRC staff requests the licensee provide the additional information requested in the following enclosures:
For Enclosure 1, please provide a response within 90 days from the date of this letter.
For Enclosure 2, please provide a response by May 31, 2018.
J. J. Hutto In accordance with Title 10 of the Code of Federal Regulations, Part 2.390 of the NRC's "Agency Rules of Practice and Procedure," a copy of this letter and Enclosures 1, 2, and 3 will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records component of NRC's ADAMS. ADAMS is accessible from the NRC website at http //www.nrc gov/reading-rm/adams.html.
Docket Nos. 50-321, 50-366, and 50-424
Enclosures:
Sincerely, Michael T. Markley, Chief Plant Licensing Branch 2-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
- 1. Request for Supplemental Information Edwin I. Hatch Nuclear Plant, Units 1 and 2
- 2. Request for Supplemental Information Vogtle Electric Generating Plant, Unit 1 cc w/encl: Listserv
REQUEST FOR SUPPLEMENTAL INFORMATION REGARDING GENERIC LETTER 2016-01 SOUTHERN NUCLEAR OPERATING COMPANY, INC.
EDWIN I. HATCH NUCLEAR PLANT, UNIT NOS. 1 AND 2 DOCKET NO. 50-321 AND 50-366 By letter dated November 2, 2016 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML16307A295), the Southern Nuclear Operating Company, Inc. (SNC, the licensee) provided a response to Generic Letter (GL) 2016-01, "Monitoring of Neutron Absorbing Materials in Spent Fuel Pools" (ADAMS Accession No. ML16097A169) for the Edwin I. Hatch Nuclear Plant (HNP), Units 1 and 2. The following information is needed for the U.S. Nuclear Regulatory Commission (NRG) staff to complete its review.
Plant-Specific Monitoring Information For licensees that utilize neutron-absorbing materials (NAM) in the SFP, the 108 areal density
{AD) of the neutron-absorbing materials (NAM) must be verified so that the assumption for the 108 minimum AD in the spent fuel pool (SFP) criticality analysis is supported. The NRC staff needs to ensure the programs are in place to monitor the condition of the NAM in the SFP are appropriate for their intended purpose. In addition, the condition of the NAM must be considered in the SFP nuclear criticality safety (NCS) analysis of record (AOR). To verify that the potential reactivity changes due to degradation or physical changes to the NAM are accounted for in the SFP NCS AOR, the following information is requested.
Hatch-RAl-1.
In the response to Question 1 (a), the licensee states that the SFP racks were installed in 1980. However, in the response to Question 2)b)(ii)(2), the licensee states that the Bora! coupons samples were placed in the SFPs on May 23, 1987. How are the Boral coupons representative of the in-service material, given the approximately 7-year difference in the length of time that the material has been exposed to the SFP conditions?
Hatch-RAl-2.
In Revision 34 of the Updated Final Safety Analysis Report (UFSAR), the licensee states that Holtec Boral racks are used in addition to the General Electric/Brooks and Perkins SFP racks that were described in the response to GL 2016-01. The scope of GL 2016-01 covers all NAM in the SFP. Please provide the appropriate information requested by GL 2016-01 for the Holtec SFP racks described in Revision 34 of the UFSAR.
Hatch-RAl-3.
In the response to Question 2)a)(iii), the licensee states:
There has not been a strict "acceptance criteria" associated with the coupon testing program, in that the purpose of the program is to determine whether deformation or degradation is occurring and for any indications of deformation or degradation to be entered into the corrective action program for further assessment of impacts, extent of condition, trending, determination of functionality, and implementation of corrective actions.
The visual examination is intended to detect missing Baral or surface anomalies. The 108 areal density determination ensures that the areal density is greater than or equal to the amount assumed in the spent fuel poor criticality calculations (0.013 g 10B/cm2).
In lieu of strict acceptance criteria, how does the monitoring program ensure adequate performance of the neutron absorbing material?
REQUEST FOR SUPPLEMENTAL INFORMATION REGARDING GENERIC LETIER 2016-01 SOUTHERN NUCLEAR OPERATING COMPANY INC.
VOGTLE ELECTRIC GENERATING PLANT UNIT 1 DOCKET NOS. 50-424 By letter dated November 2, 2016 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML16307A297), the Southern Nuclear Operating Company, Inc.
(SNC, the licensee) provided a response to Generic Letter (GL) 2016-01, "Monitoring of Neutron Absorbing Materials in Spent Fuel Pools" (ADAMS Accession No. ML16097A169) for the Vogtle Electric Generating Plant (VEGP), Unit 1. The following information is needed for the U.S.
Nuclear Regulatory Commission (NRG) staff to complete its review.
Generic Boral For licensees that utilize neutron-absorbing materials (NAM) in the SFP, the 108 areal density (AO) of the neutron-absorbing materials (NAM) must be verified so that the assumption for the 108 minimum AD in the spent fuel pool (SFP) criticality analysis is supported. The NRC staff needs to ensure the programs are in place to monitor the condition of the NAM in the SFP are appropriate for their intended purpose. In addition, the condition of the NAM must be considered in the SFP nuclear criticality safety (NCS) analysis of record {AOR). To verify that the potential reactivity changes due to degradation or physical changes to the NAM are accounted for in the SFP NCS AOR, the following information is requested. This includes any changes that would affect the neutron spectrum for the SFP in addition to any loss of neutron attenuation capability.
Industry operating experience, as described in Information Notices 2009-26, "Degradation of Neutron Absorbing Materials in the Spent Fuel Pool," (ADAMS Accession No. ML092440545) and 1983-29, "Fuel Binding Caused by Fuel Rack Deformation," {ADAMS Accession No. ML14043A291) has demonstrated that certain manufacturing processes and plant conditions (dose, chemistry, length of time installed, and installation configuration) have resulted in material deformation as a result of blisters or bulging associated with Boral.
VEGP does not appear to have a site-specific monitoring program and, consequently, SNC is relying on general industry operating experience as a surrogate for the condition of the Boral installed in the spent fuel pool.
Vogtle-RAl-1.
Please describe how industry operating experience bounds the condition of the Boral at VEGP, thereby providing assurance that any degradation or deformation that may affect the Boral at VEGP is identified.
Vogtle-RAl-2.
Please discuss the criticality impact due to relevant material deformation identified in general industry operating experience, and how it can be accommodated by the nuclear criticality safety analysis of record for VEGP without exceeding NRC subcriticality requirements.
- via email OFFICE NRR/DORULSPB/PM NRR/DORL/LPL2-1/PM NRR/DORULPL2-1/LA NAME SWall MOrenak KGoldstein *-
DATE 11/01/17 10/12/17 10/12/17 OFFICE NRR/DMLR/MCCB*
NRR/DPR/PGCB/BC(A)'
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NAME SBloom AGarmoe Rlukes DATE 09/25/17 09/22/17 09/21117 OFFICE NRR/DORULPL2-1/BC NRR/DORL/LSPB/PM NAME MMarkley SWall DATE 11/07/17 11/07/17