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{{#Wiki_filter:FINAL LICENSE RENEWAL INTERIM STAFF GUIDANCE LR-ISG-2009-01 AGING MANAGEMENT OF SPENT FUEL POOL NEUTRON-ABSORBING MATERIALS OTHER THAN BORAFLEX INTRODUCTION | {{#Wiki_filter:FINAL LICENSE RENEWAL INTERIM STAFF GUIDANCE LR-ISG-2009-01 AGING MANAGEMENT OF SPENT FUEL POOL NEUTRON-ABSORBING MATERIALS OTHER THAN BORAFLEX INTRODUCTION This final license renewal interim staff guidance (LR-ISG) LR-ISG-2009-01, Aging Management of Spent Fuel Pool Neutron-Absorbing Materials other than Boraflex, provides guidance as to one acceptable approach for managing the effects of aging during the period of extended operation for certain neutron-absorbing spent fuel pool components within the scope of the License Renewal Rule (Title 10 of the Code of Federal Regulations, Part 54, Requirements for Renewal of Operating Licenses for Nuclear Power Plants (10 CFR Part 54)). This LR-ISG recommends an aging management program (AMP) to address the potential loss of material and loss of neutron-absorbing capability of these components during the period of extended operation. A license renewal applicant may reference this AMP in its license renewal application (LRA) to demonstrate that the programs at its facility are acceptable to the U.S. | ||
Nuclear Regulatory Commission (NRC or the staff) for compliance with the License Renewal Rule, until the guidance in this final LR-ISG is implemented into the next update of the license renewal guidance documents. This LR-ISG does not apply to Boraflex, for which Section XI.M22, Boraflex Monitoring, of the Generic Aging Lessons Learned (GALL) Report (NRC, 2005a) describes adequate AMP characteristics. | |||
This final license renewal interim staff guidance (LR-ISG) LR-ISG-2009-01, | DISCUSSION Pursuant to 10 CFR 54.21, a license renewal applicant is required to demonstrate that the effects of aging on structures and components subject to an aging management review (AMR) will be adequately managed so that the intended functions will be maintained consistent with the current licensing basis for the period of extended operation. The Standard Review Plan for Review of License Renewal Applications for Nuclear Power Plants (SRP-LR) (NRC, 2005b) provides guidance to the staff reviewers performing safety reviews of applications to renew nuclear power plant licenses in accordance with 10 CFR Part 54. SRP-LR Section 3.3.2.2.6 provides acceptance criteria for spent fuel pool neutron-absorbing materials subject to an AMR. | ||
Licensees use many neutron-absorbing materials in spent fuel pools, such as Boraflex, Boral, Metamic, boron steel, and carborundum. As previously mentioned, the GALL Report describes adequate AMP characteristics for Boraflex monitoring; however, management of the aging effects of the other materials has generally not been adequately addressed in current guidance. | |||
DISCUSSION | Recent operating experience indicates several instances of degradation and/or deformation of neutron-absorbing materials in the spent fuel pools of operating reactors, as described in NRC Information Notice 2009-26, Degradation of Neutron-Absorbing Materials in the Spent Fuel Pool (NRC, 2009a). Operating experience related to two specific spent fuel pool neutron-absorbing materials is described in the following sections. | ||
Pursuant to 10 CFR 54.21, a license renewal applicant is required to demonstrate that the effects of aging on structures and components subject to an aging management review (AMR) will be adequately managed so that the intended functions will be maintained consistent with the current licensing basis for the period of extended operation. The Standard Review Plan for Review of License Renewal Applications | |||
Licensees use many neutron-absorbing materials in spent fuel pools, such as Boraflex, Boral, Metamic, boron steel, and carborundum. As previously mentioned, the GALL Report describes adequate AMP characteristics for Boraflex monitoring; however, management of the aging effects of the other materials has generally not been adequately addressed in current guidance. | |||
Recent operating experience indicates several instances of degradation and/or deformation of | |||
neutron-absorbing materials in the spent fuel | |||
Carborundum In July 2008, the licensee of Palisades Nuclear Plant discovered that the region 1 fuel storage rack contained less neutron-absorbing material than assumed in the spent fuel pool criticality analysis of record (Entergy Nuclear Operations, Inc., 2008). The Electric Power Research Institute (EPRI) defines region 1 fuel storage racks as those that receive high reactivity, unburned reload fuel (EPRI, 2006). The lack of neutron-absorbing material resulted in noncompliance with the spent fuel pool criticality requirements in Technical Specification 4.3.1.1.b. In response to this concern, the licensee performed blackness testing of the region 1 spent fuel pool racks to validate that the racks would continue to perform neutron attenuation as credited in the licensees criticality analysis of record and to satisfy regulatory requirements and renewed license commitments. | |||
The licensee performed in situ Boron-10 Areal Density Gauge for Evaluating Racks (BADGER) testing of approximately two percent of the storage locations, which revealed that the Boron-10 areal density of the spent fuel pool racks was, at a minimum, approximately one-third of its original design value. The neutron-absorbing material, plate-type carborundum, which is relied on to maintain subcriticality in the spent fuel pool, was much less effective than assumed in the criticality analysis. Therefore, region 1 of the spent fuel pool no longer met the requirements of 10 CFR 50.68, Criticality Accident Requirements, or Technical Specification 4.3.1.1.b, which require that K-effective (Keff) for region 1 fuel racks be less than or equal to 0.95 if fully flooded with unborated water. | |||
The licensee determined that the apparent cause of the degradation of the carborundum B4C plates was the spent fuel pool environment. The exact degradation mechanism or mechanisms are not clearly understood, but likely involve changes in the physical properties of the carborundum B4C plates that occur during prolonged exposure to the spent fuel pool environment. The swelling of the racks, which prevents fuel assemblies from being inserted or removed, may indicate a potential problem with neutron-absorbing capacity. The swelling in the racks could result from dimensional changes of the carborundum, which may be replaced by a gas-filled space, and could challenge the assumptions of the criticality analysis. This degradation may have been occurring as early as 1988 when the first impedance to inserting a fuel assembly was documented at Palisades Nuclear Plant. Since there was no surveillance of the neutron-absorbing capacity of the material, the start of the degradation and the degradation rate are unknown. | |||
Boral An LRA supplement (FirstEnergy Nuclear Operating Company, 2009) indicates that inspections of the Boral neutron-absorber material coupons at the Beaver Valley Power Station in 2007 identified numerous blisters of the aluminum cladding, while only a few small blisters were identified in 2002. In region 1 fuel storage racks, blisters can displace water from the flux traps between storage cells and challenge dimensional assumptions used in the criticality analysis. | Boral An LRA supplement (FirstEnergy Nuclear Operating Company, 2009) indicates that inspections of the Boral neutron-absorber material coupons at the Beaver Valley Power Station in 2007 identified numerous blisters of the aluminum cladding, while only a few small blisters were identified in 2002. In region 1 fuel storage racks, blisters can displace water from the flux traps between storage cells and challenge dimensional assumptions used in the criticality analysis. | ||
Based on these inspections, the licensee for Beaver Valley Power Station determined that the blistering of Boral aluminum cladding was an aging effect and that it would credit the existing Boral Surveillance Program for management of this aging. In addition, blistering of Boral neutron-absorbing material has also been observed at Seabrook Station (FPL Energy Seabrook Station, 2003). | Based on these inspections, the licensee for Beaver Valley Power Station determined that the blistering of Boral aluminum cladding was an aging effect and that it would credit the existing Boral Surveillance Program for management of this aging. In addition, blistering of Boral neutron-absorbing material has also been observed at Seabrook Station (FPL Energy Seabrook Station, 2003). | ||
In a letter responding to a staff request for additional information (PPL Susquehanna, LLC, 2009), the licensee for Susquehanna Steam Electric Station stated that it identified a significant | |||
In a letter responding to a staff request for additional information (PPL Susquehanna, LLC, 2009), the licensee for Susquehanna Steam Electric Station stated that it identified a significant | |||
bulge in a poison can wall. Although the licensee did not definitively determine the cause of the bulge, its letter states that it may be the result of hydrogen gas generation from either moisture contained in the Boral at the time of manufacture or a leaking seal weld in the poison can. This bulge prevented the placement of a blade guide into the deformed cell. | |||
Also, Section B.3.28, Water Chemistry Control Program of the LRA for Vogtle Electric Generating Plant (Southern Nuclear Operating Co., Inc (SNC), 2007) states that the spent fuel pool water chemistry program showed an increase in the concentration of aluminum, which may indicate loss of material from the Boral neutron-absorbing material. | |||
Further, an Electric Power Research Institute report (EPRI, 2006), states the following concerning Boral: | |||
in-pool blistering of BORAL' has, to date, proved to be primarily an esthetic effect; however, the potential effects on fuel assembly clearance and the reactivity state of Region 1 racks have been noted. In addition, it has been noted that, in a few instances, rack cell wall deformation has occurred making it difficult to remove fuel. With plant life extension now the norm at most [light water reactors] in the US, some BORAL', which originally had a design service life of 40 years, will be in service more than 60 years. This suggests a prudent course is continued vigilance and surveillance so that onset of any degradation can be detected early and appropriate mitigation measures applied. | |||
ACTION The recent instances of degradation and deformation of spent fuel pool neutron-absorbing materials, as discussed above, have led the staff to re-evaluate the SRP-LR and GALL Report guidance in this area. Based on the operating experience and other industry information, the staff has identified that the current license renewal guidance documents do not provide sufficient guidance to address the information that should be included in an LRA to demonstrate adequate management of the potential loss of material and loss of neutron-absorbing capability of the neutron-absorber material in spent fuel pools for the period of extended operation. As such, the staff has determined that the existing guidance requires clarification to address that, for each type of neutron-absorber material used in the applicants spent fuel pool(s), the applicant should demonstrate in their specific spent fuel pool environment for their specific material(s) that degradation has not occurred in a manner that could adversely impact the materials intended function. The staff has also developed a generic AMP, Monitoring of Neutron-Absorbing Materials other than Boraflex, that is recommend for managing the aging effects associated with these spent fuel pool neutron-absorbing materials. | |||
Necessary revisions to the various license renewal guidance documents are in Appendix A, Revisions to SRP-LR, Appendix B, Revisions to GALL Report, Volume 1, and Appendix C, Revisions to GALL Report, Volume 2. Appendix D, Mark-Up Showing Changes to the License Renewal Guidance Documents, shows these revisions as compared to the current license renewal guidance documents. An overview of these changes is discussed below. | |||
In the GALL Report, the generic AMP referenced above will be included under a new Section XI.M40 in GALL Report, Volume 2. Aging management of spent fuel pool neutron-absorbing materials other than Boraflex is addressed under two specific line items, VII.A2-3 and VII.A2-5, in GALL Report, Volume 2. These items currently recommend a plant-specific AMP and further evaluation. However, since the staff has determined that the new generic program | |||
of the | is adequate for managing the associated aging effects with no further evaluation recommended, a plant-specific program is no longer recommended and corresponding changes the line items Aging Management Program (AMP) and Further Evaluation descriptions are necessary. In addition, the staff has determined that the Material and Aging Effect/Mechanism descriptions for these line items require clarification. Changes to the GALL Report, Volume 1, Table 3 summary item (identification number 13) related to these two line items are also necessary to reflect the changes to GALL Report, Volume 2. The final changes to the GALL Report are in Appendices B and C. | ||
Several changes are also necessary to the SRP-LR. Due to the staffs determination that the new generic AMP is adequate for managing the aging effects with no further plant-specific evaluation recommended, the acceptance criteria and review procedures in SRP-LR Sections 3.3.2.2.6 and 3.3.3.2.6, respectively, are no longer necessary. Revisions to SRP-LR Table 3.3-1 are also necessary for consistency with the changes to Table 3 of GALL Report, Volume 1. In addition, an example final safety analysis report supplement for the new AMP needs to be added to SRP-LR Table 3.3-2. The final changes to the SRP-LR are in Appendix A. | |||
The staff also notes that applicants should consider both plant-specific and industry operating experience in the LRA. The applicants plant-specific operating experience should be based on either data from on-going inspection and/or monitoring programs, or from other operational findings. The use of test data that does not bound the age of the material at the end of the period of extended operation is not sufficient since there is not sufficient evidence that extrapolation or accelerated testing is valid in these cases. For instance, the licensee for the Palisades Nuclear Plant extrapolated data through the period of extended operation which projected that no significant degradation was to be expected, but a surveillance inspection revealed unexpected degradation of the neutron-absorbing capacity of plate-type carborundum. | |||
If the applicant has a surveillance program in place for the material, a description of the program and results can be applied to the AMR as operating experience. This program should provide reasonable assurance that the material will be properly managed and that future degradation will be detected in the period of extended operation. In addition, continuation of an on-going coupon inspection program is adequate, but if there is no on-going coupon sample program, then the LRA will need to propose a new inspection program. | |||
The guidance in this final LR-ISG is approved for use by the staff and stakeholders. On December 1, 2009, the staff issued a Federal Register notice (NRC, 2009b) to request public comments on draft LR-ISG-2009-01, Staff Guidance Regarding Plant-Specific Aging Management Review and Aging Management Program for the Neutron-Absorber Material in the Spent Fuel Pool Associated with License Renewal Applications. In response, by letters dated December 17, 2009 (SNC, 2009), and December 28, 2009 (Exelon Generation Company, LLC, 2009), the NRC received comments from SNC and Exelon Generation Company, LLC, respectively. The NRC also received comments form the Nuclear Energy Institute (NEI) by letter dated December 31, 2009 (NEI, 2009a), and by email dated January 6, 2010 (NEI, 2010). | |||
The NRC staff considered these comments in developing the final LR-ISG-2009-01. The staffs responses to these comments are in Appendix E, Resolution of Public Comments on Draft LR-ISG-2009-01. The title of the LR-ISG has been changed from the draft title, Staff Guidance Regarding Plant-Specific Aging Management Review and Aging Management Program for the Neutron-Absorber Material in the Spent Fuel Pool Associated with License Renewal Applications, to the final, Aging Management of Spent Fuel Pool Neutron-Absorbing Materials other than Boraflex, to clarify that this LR-ISG provides guidance concerning generic, not plant-specific, aging management recommendations. | |||
BACKFITTING DISCUSSION This LR-ISG contains guidance as to one acceptable approach for managing the effects of aging during the period of extended operation for certain spent fuel pool neutron-absorbing materials within the scope of license renewal. Set forth below is the staff's discussion on: | |||
(i) whether this LR-ISG addresses newly identified systems, structures, or components (SSCs) subject to aging management under 10 CFR 54.37(b), and (ii) compliance with the requirements of the Backfit Rule, 10 CFR 50.109. | |||
Newly Identified SSCs under 10 CFR 54.37(b) | Newly Identified SSCs under 10 CFR 54.37(b) | ||
The NRC is not proposing to treat neutron-absorbing materials (other than Boraflex) in the spent fuel pools as newly identified SSCs under 10 CFR 54.37(b). Therefore, any additional action on such materials which the NRC may impose upon current holders of renewed operating licenses under 10 CFR Part 54 would not fall within the scope of 10 CFR 54.37(b). The NRC would have to address compliance with the requirements of 10 CFR 50.109, before it may impose any new aging management requirements for these neutron absorbing materials on current holders of renewed operating licenses (see discussion below). | |||
Compliance with the Backfit Rule Issuance of this LR-ISG does not constitute backfitting as defined in 10 CFR 50.109(a)(1), and the NRC staff did not prepare a backfit analysis for issuing this LR-ISG. There are several rationales for this conclusion, depending upon the status of the nuclear power plant licensee. | |||
Current operating license holders who have not applied for renewed licenses - This LR-ISG is not directed at holders of (original) operating licenses. Although the NRC is evaluating the issues identified in this LR-ISG for applicability to holders of original operating licenses, the NRC has not yet determined whether additional regulatory action must be initiated to address these issues. Any regulatory requirements imposed by the NRC as the result of this evaluation must be implemented consistent with the provisions of 10 CFR Part 50 and the Backfit Rule. | |||
Therefore, issuance of this ISG does not constitute backfitting as applied to current holders of (original) operating licenses. | |||
Licensees who are currently in the license renewal process - This LR-ISG is directed to current applicants for license renewal. However, this LR-ISG is not backfitting as defined in 10 CFR 50.109(a)(1). This guidance is non-binding and provides one approach acceptable to the NRC staff for managing the effects of aging of neutron-absorbing materials in the spent fuel pools in accordance with the requirements of 10 CFR Part 54. License renewal applicants are not required to use this guidance. Applicants may elect to propose an alternative approach for managing the aging of neutron-absorbing materials in spent fuel pools during the period of extended operation. In addition, the Backfit Rule does not protect license renewal applicants voluntarily requesting renewed licenses from changes in NRC requirements or guidance on license renewal prior to or during the pendency of their renewal application (NRC, 2008). | |||
Therefore, issuance of this LR-ISG does not constitute backfitting as applied to current applicants for license renewal. | |||
Licensees who already hold a renewed license - This guidance is also directed to licensees who already hold a renewed license. However, this guidance is non-binding and the LR-ISG does not require current holders of renewed licenses to take any action (i.e., programmatic or plant hardware changes for managing the aging of neutron-absorbing materials in spent fuel | |||
pools). However, the NRC expects renewed license holders to review the information in this LR-ISG and consider actions consistent with this guidance as appropriate. If, in the future, the NRC decides to take additional action and impose requirements for management of neutron-absorbing materials in spent fuel pools, then the NRC will follow the requirements of the Backfit Rule. | |||
REFERENCES 10 CFR Part 54, Requirements for Renewal of Operating Licenses for Nuclear Power Plants, Office of the Federal Register, National Archives and Records Administration, 2010. | |||
NRC decides to take additional action and impose requirements for management of neutron-absorbing materials in spent fuel pools, then the NRC will follow the requirements of the Backfit Rule. REFERENCES 10 CFR Part 54, Requirements for Renewal of Operating Licenses for Nuclear Power Plants , Office of the Federal Register, National Archives and Records Administration, 2010. | |||
10 CFR Part 50, Domestic Licensing of Production and Utilization Facilities, Office of the Federal Register, National Archives and Records Administration, 2010. | 10 CFR Part 50, Domestic Licensing of Production and Utilization Facilities, Office of the Federal Register, National Archives and Records Administration, 2010. | ||
Electric Power Research Institute (EPRI). 2006. | Electric Power Research Institute (EPRI). 2006. Handbook of Neutron Absorber Materials for Spent Fuel Transportation and Storage Applications. Palo Alto, CA. 1013721. (2006). | ||
Handbook of Neutron Absorber Materials for Spent Fuel Transportation and Storage Applications. Palo Alto, CA. 1013721. | Entergy Nuclear Operations, Inc. 2008. Letter from Christopher J. Schwarz, Entergy Nuclear Operations, Inc., Palisades Nuclear Plant, to U.S. Nuclear Regulatory Commission, Commitments to Address Degraded Spent Fuel Pool Storage Rack Neutron Absorber. | ||
(August 27, 2008). ADAMS No. ML082410132. | |||
Entergy Nuclear Operations, Inc. 2008. Letter from Christopher J. Schwarz, Entergy Nuclear Operations, Inc., Palisades Nuclear Plant, to U.S. Nuclear Regulatory Commission, | Exelon Generation Company, LLC. 2009. Letter from Patrick R. Simpson, Exelon Generation Company, LLC, to Michael Lesar, U.S. Nuclear Regulatory Commission, Comments on Draft License Renewal Interim Staff Guidance LR-ISG-2009-01. (December 28, 2009). | ||
ADAMS No. ML100060388. | |||
Exelon Generation Company, LLC. 2009. Letter from Patrick R. Simpson, Exelon Generation Company, LLC, to Michael Lesar, U.S. Nuclear Regulatory Commission, | FirstEnergy Nuclear Operating Company. 2009. Letter from Kevin L. Ostrowski, FirstEnergy Nuclear Operating Company, to the U.S. Nuclear Regulatory Commission, Supplemental Information for the Review of the Beaver Valley Power Station, Units 1 and 2, License Renewal Application (TAC Nos. MD6593 and MD6594) and License Renewal Application Amendment No. 34. (January 19, 2009). ADAMS No. ML090220216. | ||
FPL Energy Seabrook Station. 2003. Letter from Mark E. Warner, FPL Energy Seabrook Station, to the U.S. Nuclear Regulatory Commission, Seabrook Station Boral Spent Fuel Pool Test Coupons Report Pursuant to 10 CFR Part 21.21. (October 6, 2003). | |||
FirstEnergy Nuclear Operating Company. 2009. Letter from Kevin L. Ostrowski, FirstEnergy Nuclear Operating Company, to the U.S. Nuclear Regulatory Commission, | ADAMS No. ML032880525. | ||
Nuclear Energy Institute (NEI). 2009a. Letter from James H. Riley, NEI, to the Chief, Rulemaking, Directives, and Editing Branch, U.S. Nuclear Regulatory Commission, Proposed License Renewal Interim Staff Guidance LR-ISG-2009-01, Staff Guidance Regarding Plant-Specific Aging Management Review and Aging Management Program for Neutron-Adsorbing Material in Spent Fuel Pools. (December 31, 2009). ADAMS No. ML100060387. | |||
FPL Energy Seabrook Station. 2003. Letter from Mark E. Warner, FPL Energy Seabrook Station, to the U.S. Nuclear Regulatory Commission, | Nuclear Energy Institute (NEI). 2010. Email from Julie Keys, NEI, to Ian Spivack, U.S. Nuclear Regulatory Commission, Fw: Draft LR-ISG-2009. (January 6, 2010). ADAMS No. ML100280648. | ||
Nuclear Energy Institute (NEI). 2009a. Letter from James H. Riley, NEI, to the Chief, Rulemaking, Directives, and Editing Branch, U.S. Nuclear Regulatory Commission, | |||
Nuclear Energy Institute (NEI). 2010. Email from Julie Keys, NEI, to Ian Spivack, U.S. Nuclear Regulatory Commission, | |||
PPL Susquehanna, LLC. 2009. Letter from W. H. Spence, PPL Susquehanna, LLC, to the U.S. | |||
Nuclear Regulatory Commission, Susquehanna Steam Electric Station Request for Additional Information for the Review of the Susquehanna Steam Electric Station Units 1 and 2, License Renewal Application (LRA) Section 3.3.2.2.6. (May 13, 2009). ADAMS No. ML091520031. | |||
Southern Nuclear Operating Company, Inc. (SNC). 2007. License Renewal Application Vogtle Electric Generating Plant Units 1 and 2. (June 30, 2007). ADAMS No. ML071840360. | |||
Southern Nuclear Operating Company, Inc. (SNC). 2009. Letter from M. J. Ajluni, Southern Nuclear Operating Company, Inc., to the U.S. Nuclear Regulatory Commission, Comments on Draft License Renewal Interim Staff Guidance, LR-ISG-2009-01: Staff Guidance Regarding Plant-Specific Aging Management Review and Aging Management Program for Neutron-Absorbing Material in Spent Fuel Pools (Docket ID NRC-2009-0521). (December 17, 2009). ADAMS No. ML093570197. | |||
U.S. Nuclear Regulatory Commission (NRC). 2005a. Generic Aging Lessons Learned (GALL) | U.S. Nuclear Regulatory Commission (NRC). 2005a. Generic Aging Lessons Learned (GALL) | ||
Report. Washington, D.C. NUREG-1801, Revision 1, Vols. 1 and 2. | Report. Washington, D.C. NUREG-1801, Revision 1, Vols. 1 and 2. (September 2005). | ||
U.S. Nuclear Regulatory Commission (NRC). 2005b. | ADAMS Nos. ML052770419 and ML052780376. | ||
Standard Review Plan for Review of License Renewal Applications for Nuclear Power Plants. Washington, D.C. NUREG-1800, Revision 1. | U.S. Nuclear Regulatory Commission (NRC). 2005b. Standard Review Plan for Review of License Renewal Applications for Nuclear Power Plants. Washington, D.C. | ||
NUREG-1800, Revision 1. (September 2005). ADAMS No. ML052110007. | |||
U.S. Nuclear Regulatory Commission (NRC). 2008. Memorandum from Dale E. Klein, Chairman, to Hubert T. Bell, Office of the Inspector General, | U.S. Nuclear Regulatory Commission (NRC). 2008. Memorandum from Dale E. Klein, Chairman, to Hubert T. Bell, Office of the Inspector General, Response to Recommendation 8 of 9/6/07 Audit Report on NRCs License Renewal Program. | ||
(April 1, 2008). ADAMS No. ML080870286. | (April 1, 2008). ADAMS No. ML080870286. | ||
U.S. Nuclear Regulatory Commission (NRC). 2009a. Information Notice 2009-26, Degradation of Neutron-Absorbing Materials in the Spent Fuel Pool. (October 28, 2009). ADAMS No. ML092440545. | |||
U.S. Nuclear Regulatory Commission (NRC). 2009a. Information Notice 2009-26, | U.S. Nuclear Regulatory Commission (NRC). 2009b. Draft License Renewal Interim Staff Guidance LR-ISG-2009-01 Staff Guidance Regarding Plant-Specific Aging Management Review and Aging Management Program for the Neutron Absorber Material in the Spent Fuel Pool Associated with License Renewal Applications; Solicitation of Public Comment. Federal Register. Washington, D.C. Vol. 229, No. 74, pp. 62829-62830. | ||
(December 1, 2009). | |||
U.S. Nuclear Regulatory Commission (NRC). 2009b. | |||
Federal Register. Washington, D.C. Vol. 229, No. 74, pp. 62829-62830. | |||
- | APPENDIX A REVISIONS TO SRP-LR | ||
Table 3.3-1. Summary of Aging Management Programs for Auxiliary Systems Evaluated in Chapter VII of the GALL Report ID Type Component Aging Aging Management Further Evaluation Related Effect/Mechanism Programs Recommended Item 13 BWR/ Boral, boron steel and other Reduction of neutron- Monitoring of Neutron- No A-88 PWR materials (excluding Boraflex) absorbing capacity, Absorbing Materials other A-89 utilized as neutron absorbers in changes in dimension than Boraflex spent fuel storage racks neutron- that increase Keff, and absorbing sheets exposed to loss of material due to treated water or treated borated neutron-absorber water degradation and radiation | |||
- A | |||
- A Table 3.3-2. FSAR Supplement for Aging Management of Auxiliary Systems Implementation Program Description of Program Schedule* | |||
Monitoring of Neutron- The program is implemented to assure that Program should Absorbing Materials other degradation of spent fuel pool neutron-absorbing be implemented than Boraflex material that could compromise the criticality before the period analysis will be detected in the period of extended of extended operation. The loss of material and the operation. | |||
degradation of the neutron-absorbing material capacity are determined through coupon testing, direct in situ testing, or both. Such testing includes periodic verification of boron loss through areal density measurement of coupons or through direct in situ techniques, such as measurement of boron areal density, measurement of geometric changes in the material (blistering, pitting, and bulging), | |||
and detection of gaps through blackness testing. | |||
APPENDIX B REVISIONS TO GALL REPORT, VOLUME 1 | |||
and | Table 3. Summary of Aging Management Programs for the Auxiliary Systems Evaluated in Chapter VII of the GALL Report Further Related Aging Aging Management Unique ID Type Component Evaluation Generic Effect/Mechanism Programs Item Recommended Item 13 BWR/ Boral, boron steel and other Reduction of neutron- Monitoring of Neutron- No A-88 VII.A2-5 PWR materials (excluding absorbing capacity, Absorbing Materials other A-89 VII.A2-3 Boraflex) utilized as neutron changes in dimension than Boraflex absorbers in spent fuel that increase Keff, and storage racks neutron- loss of material due to absorbing sheets exposed to neutron-absorber treated water or treated degradation and borated water radiation | ||
- B APPENDIX C REVISIONS TO GALL REPORT, VOLUME 2 | |||
Neutron- absorbing sheets - | VII AUXILIARY SYSTEMS A2 Spent Fuel Storage Structure Aging Effect/ Further Item Link and/or Material Environment Aging Management Program (AMP) | ||
Mechanism Evaluation Component VII.A2-3 VII.A2.1-b Spent fuel Boral, Treated water Reduction of Chapter XI.M40, Monitoring of No storage racks boron steel neutron- Neutron-Absorbing Materials other (A-89) and other absorbing than Boraflex Neutron- materials capacity, absorbing (excluding changes in sheets - Boraflex) dimension that BWR utilized as increase Keff, neutron and loss of absorbers material due to neutron-absorber degradation and radiation | |||
- C VII.A2-5 VII.A2.1-b Spent fuel Boral, Treated Reduction of Chapter XI.M40, Monitoring of No storage racks boron steel borated water neutron- Neutron-Absorbing Materials other (A-88) and other absorbing then Boraflex Neutron- materials capacity, absorbing (excluding changes in sheets - Boraflex) dimension that PWR utilized as increase Keff, neutron and loss of absorbers material due to neutron-absorber degradation and radiation | |||
- C XI.M40 MONITORING OF NEUTRON-ABSORBING MATERIALS OTHER THAN BORAFLEX Program Description A monitoring program is implemented to assure that degradation of the neutron-absorbing material used in spent fuel pools that could compromise the criticality analysis will be detected. | |||
- C XI.M40 MONITORING OF NEUTRON-ABSORBING MATERIALS OTHER THAN BORAFLEX | |||
The applicable aging management program (AMP) relies on periodic inspection, testing, monitoring, and analysis of the criticality design to assure that the required five percent subcriticality margin is maintained during the renewed license period. | The applicable aging management program (AMP) relies on periodic inspection, testing, monitoring, and analysis of the criticality design to assure that the required five percent subcriticality margin is maintained during the renewed license period. | ||
Evaluation and Technical Basis | Evaluation and Technical Basis | ||
: 1. Scope of Program | : 1. Scope of Program: The AMP manages the effects of aging on neutron-absorbing components/materials used in spent fuel racks. | ||
: The AMP manages the effects of aging on neutron-absorbing components/materials used in spent fuel racks. | : 2. Preventive Actions: This AMP is a condition monitoring program and therefore there are no preventative actions. | ||
: 2. Preventive Actions | : 3. Parameters Monitored/Inspected: For these materials, gamma irradiation and/or long-term exposure to the wet pool environment may cause shrinkage resulting in loss of material, and changes in dimension (such as gap formation, formation of blisters, pits and bulges) which could result in loss of neutron absorbing capability of the material. The parameters monitored include the physical condition of the neutron-absorbing materials, such as in situ gap formation, geometric changes in the material (formation of blisters, pits, and bulges) as observed from coupons or in situ, and decreased boron areal density, etc. The parameters monitored should be directly related to determination of the loss of material or loss of neutron absorption capability of the material(s). | ||
: This AMP is a condition monitoring program and therefore there are no preventative actions. | : 4. Detection of Aging Effects: The loss of material and the degradation of the neutron-absorbing material capacity are determined through coupon and/or direct in situ testing. | ||
: 3. Parameters Monitored/Inspected | Such testing should include periodic verification of boron loss through areal density measurement of coupons or through direct in situ techniques which may include measurement of boron areal density, geometric changes in the material (blistering, pitting, and bulging), and detection of gaps through blackness testing. The frequency of the inspection and testing depends on the condition of the neutron-absorbing material and should be determined and justified with plant-specific operating experience by the licensee, not to exceed 10 years. | ||
: For these materials, gamma irradiation and/or long-term exposure to the wet pool environment may cause shrinkage resulting in loss of material, and changes in dimension (such as gap formation, formation of blisters, pits and bulges) which could result in loss of neutron absorbing capability of the material. The parameters monitored include the physical condition of the neutron-absorbing materials, such as in situ gap formation, geometric changes in the material (formation of blisters, pits, and bulges) as observed from coupons or in situ, and decreased boron areal density, etc. The parameters monitored should be directly related to determination of the loss of material or loss of neutron absorption capability of the material(s). | : 5. Monitoring and Trending: The measurements from periodic inspections and analysis are compared to baseline information or prior measurements and analysis for trend analysis. | ||
: 4. Detection of Aging Effects | The approach for relating the measurements to the performance of the spent fuel neutron absorber materials shall be specified by the applicant, considering differences in exposure conditions, vented/non-vented test samples and spent fuel racks, etc. | ||
: The loss of material and the degradation of the neutron-absorbing material capacity are determined through coupon and/or direct in situ testing. Such testing should include periodic verification of boron loss through areal density measurement of coupons or through direct in situ techniques which may include measurement of boron areal density, geometric changes in the material (blistering, pitting, and bulging), and detection of gaps through blackness testing. The frequency of the inspection and testing depends on the condition of the neutron-absorbing material and should be determined and justified with plant-specific operating experience by the licensee, not to exceed 10 years. | : 6. Acceptance Criteria: Although the goal is to ensure maintenance of the five percent subcriticality margin for the spent fuel pool, the specific acceptance criteria for the measurements and analyses shall be specified by the applicant. | ||
: 5. Monitoring and Trending | : 7. Corrective Actions: Corrective actions are initiated if the results from measurements and analysis indicate that the five percent subcriticality margin cannot be maintained because of | ||
: The measurements from periodic inspections and analysis are compared to baseline information or prior measurements and analysis for trend analysis. The approach for relating the measurements to the performance of the spent fuel neutron absorber materials shall be specified by the applicant, considering differences in exposure conditions, vented/non-vented test samples and spent fuel racks, etc. | |||
: 6. Acceptance Criteria | |||
: Although the goal is to ensure maintenance of the five percent subcriticality margin for the spent fuel pool, the specific acceptance criteria for the measurements and analyses shall be specified by the applicant. | |||
: 7. Corrective Actions | |||
: Corrective actions are initiated if the results from measurements and analysis indicate that the five percent subcriticality margin cannot be maintained because of | |||
- C the current or projected future degradation of the neutron-absorbing material. Corrective actions may consist of providing additional neutron-absorbing capacity with an alternate material, or applying other options, which are available to maintain the subcriticality margin. As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B, acceptable to address the corrective actions. | - C the current or projected future degradation of the neutron-absorbing material. Corrective actions may consist of providing additional neutron-absorbing capacity with an alternate material, or applying other options, which are available to maintain the subcriticality margin. | ||
: 8. Confirmation Process | As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B, acceptable to address the corrective actions. | ||
: Site quality assurance (QA) procedures, site review and approval processes, and administrative controls are implemented in accordance with the requirements of 10 CFR Part 50, Appendix B. As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B acceptable to address the confirmation process and administrative controls. | : 8. Confirmation Process: Site quality assurance (QA) procedures, site review and approval processes, and administrative controls are implemented in accordance with the requirements of 10 CFR Part 50, Appendix B. As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B acceptable to address the confirmation process and administrative controls. | ||
: 9. Administrative Controls | : 9. Administrative Controls: As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B, acceptable to address administrative controls. | ||
: As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B, acceptable to address administrative controls. | : 10. Operating Experience: Applicants for license renewal should reference plant-specific operating experience and industry experience to provide reasonable assurance that the program will be able to detect degradation of the neutron absorbing material in the applicants spent fuel pool. Some of the industry operating experience that should be included is listed below: | ||
: 10. Operating Experience | : 1. Loss of material from the neutron absorbing material has been seen at many plants, including loss of aluminum which was detected by monitoring the aluminum concentration in the spent fuel pool. One instance of this was documented in the Vogtle LRA Water Chemistry Program B.3.28. | ||
: Applicants for license renewal should reference plant-specific operating experience and industry experience to provide reasonable assurance that the program will be able to detect degradation of the neutron absorbing material in the | : 2. Blistering has also been noted at many plants. Examples include blistering at Seabrook and Beaver Valley. | ||
: 1. Loss of material from the neutron absorbing material has been seen at many plants, including loss of aluminum which was detected by monitoring the aluminum concentration in the spent fuel pool. One instance of this was documented in the Vogtle LRA Water Chemistry Program B.3.28. 2. Blistering has also been noted at many plants. Examples include blistering at Seabrook and Beaver Valley. 3. The significant loss of neutron-absorbing capacity of the plate-type carborundum material has been reported at Palisades. | : 3. The significant loss of neutron-absorbing capacity of the plate-type carborundum material has been reported at Palisades. | ||
The applicant should describe how the monitoring program described above is capable of detecting the aforementioned degradation mechanisms. | The applicant should describe how the monitoring program described above is capable of detecting the aforementioned degradation mechanisms. | ||
References | References Letter from Christopher J. Schwarz, Entergy Nuclear Operations, Inc., Palisades Nuclear Plant, to the U.S. Nuclear Regulatory Commission, Commitments to Address Degraded Spent Fuel Pool Storage Rack Neutron Absorber, August 27, 2008, (ADAMS Accession No. ML082410132). | ||
Letter from Kevin L. Ostrowski, FirstEnergy Nuclear Operating Company, to the U.S. Nuclear Regulatory Commission, Supplemental Information for the Review of the Beaver Valley Power Station, Units 1 and 2, License Renewal Application (TAC Nos. MD6593 and MD6594) and License Renewal Application Amendment No. 34, January 19, 2009, (ADAMS Accession No. ML090220216). | |||
Letter from Christopher J. Schwarz, Entergy Nuclear Operations, Inc., Palisades Nuclear Plant, to the U.S. Nuclear Regulatory Commission, Commitments to Address Degraded Spent Fuel Pool Storage Rack Neutron Absorber , August 27, 2008, (ADAMS Accession No. ML082410132). | Letter from Mark E. Warner, FPL Energy Seabrook Station, to the U.S. Nuclear Regulatory Commission, Seabrook Station Boral Spent Fuel Pool Test Coupons Report Pursuant to 10 CFR Part 21.21, October 6, 2003 (ADAMS Accession No. ML032880525). | ||
- C License Renewal Application Vogtle Electric Generating Plant Units 1 and 2, Southern Nuclear Operating Company, Inc., June 30, 2007 (ADAMS Accession No. ML071840360). | |||
APPENDIX D MARK-UP SHOWING CHANGES TO THE LICENSE RENEWAL GUIDANCE DOCUMENTS | |||
- D control program should be verified to ensure that cracking is not occurring. The GALL Report recommends that a plant-specific aging management program be evaluated to verify the absence of cracking due to SCC and cyclic loading to ensure that these aging effects are managed adequately. An acceptable verification program is to include temperature and radioactivity monitoring of the shell side water, and eddy current testing of tubes. | |||
- D | |||
: 2. Cracking due to SCC and cyclic loading could occur in stainless steel PWR regenerative heat exchanger components exposed to treated borated water greater than 60°C (>140°F). | : 2. Cracking due to SCC and cyclic loading could occur in stainless steel PWR regenerative heat exchanger components exposed to treated borated water greater than 60°C (>140°F). | ||
The existing aging management program relies on monitoring and control of primary water chemistry in PWRs to manage the aging effects of cracking due to SCC. However, control of water chemistry does not preclude cracking due to SCC and cyclic loading. Therefore, the effectiveness of the water chemistry control program should be verified to ensure that cracking is not occurring. The GALL Report recommends that a plant-specific aging management program be evaluated to verify the absence of cracking due to SCC and cyclic loading to ensure that these aging effects are managed adequately. Acceptance criteria are described in Branch Technical Position RLSB-1 (Appendix A.1 of this SRP-LR.) | The existing aging management program relies on monitoring and control of primary water chemistry in PWRs to manage the aging effects of cracking due to SCC. However, control of water chemistry does not preclude cracking due to SCC and cyclic loading. Therefore, the effectiveness of the water chemistry control program should be verified to ensure that cracking is not occurring. The GALL Report recommends that a plant-specific aging management program be evaluated to verify the absence of cracking due to SCC and cyclic loading to ensure that these aging effects are managed adequately. Acceptance criteria are described in Branch Technical Position RLSB-1 (Appendix A.1 of this SRP-LR.) | ||
Line 191: | Line 139: | ||
3.3.2.2.5 Hardening and Loss of Strength due to Elastomer Degradation | 3.3.2.2.5 Hardening and Loss of Strength due to Elastomer Degradation | ||
: 1. Hardening and loss of strength due to elastomer degradation could occur in elastomer seals and components of heating and ventilation systems exposed to air - indoor uncontrolled (internal/external. The GALL Report recommends further evaluation of a plant-specific aging management program to ensure that these aging effects are adequately managed. | : 1. Hardening and loss of strength due to elastomer degradation could occur in elastomer seals and components of heating and ventilation systems exposed to air - indoor uncontrolled (internal/external. The GALL Report recommends further evaluation of a plant-specific aging management program to ensure that these aging effects are adequately managed. | ||
Acceptance criteria are described in Branch Technical Position RLSB-1 (Appendix A.1 of | Acceptance criteria are described in Branch Technical Position RLSB-1 (Appendix A.1 of this SRP-LR.) | ||
this SRP-LR.) | |||
: 2. Hardening loss of strength due to elastomer degradation could occur in elastomer linings of the filters, valves, and ion exchangers in spent fuel pool cooling and cleanup systems (BWR and PWR) exposed to treated water or to treated borated water. The GALL Report recommends that a plant-specific aging management program be evaluated to determine and assesses the qualified life of the linings in the environment to ensure that these aging effects are adequately managed. Acceptance criteria are described in Branch Technical Position RLSB-1 (Appendix A.1 of this SRP-LR.) | : 2. Hardening loss of strength due to elastomer degradation could occur in elastomer linings of the filters, valves, and ion exchangers in spent fuel pool cooling and cleanup systems (BWR and PWR) exposed to treated water or to treated borated water. The GALL Report recommends that a plant-specific aging management program be evaluated to determine and assesses the qualified life of the linings in the environment to ensure that these aging effects are adequately managed. Acceptance criteria are described in Branch Technical Position RLSB-1 (Appendix A.1 of this SRP-LR.) | ||
3.3.2.2.6 Reduction of Neutron | 3.3.2.2.6 Reduction of Neutron-Absorbing Capacity and Loss of Material due to General Corrosion Reduction of neutron-absorbing capacity and loss of material due to general corrosion could occur in the neutron-absorbing sheets of BWR and PWR spent fuel storage racks exposed to treated water or to treated borated water. The GALL Report recommends further evaluation of a NUREG-1800, Rev. 1 3.3-4 September 2005 | ||
-Absorbing Capacity and Loss of Material due to General Corrosion | |||
-absorbing capacity and loss of material due to general corrosion could occur in the neutron | |||
-absorbing sheets of BWR and PWR spent fuel storage racks exposed to treated water or to treated borated water. The GALL Report recommends further evaluation of a | |||
- D plant-specific aging management program to ensure that these aging effects are adequately managed. Acceptance criteria are described in Branch Technical Position RLSB-1 (Appendix A.1 of this SRP-LR). | |||
3.3.2.2.7 Loss of Material due to General, Pitting, and Crevice Corrosion | |||
: 1. Loss of material due to general, pitting, and crevice corrosion could occur in steel piping, piping components, and piping elements, including the tubing, valves, and tanks in the reactor coolant pump oil collection system, exposed to lubricating oil (as part of the fire protection system). The existing aging management program relies on the periodic sampling and analysis of lubricating oil to maintain contaminants within acceptable limits, thereby preserving an environment that is not conducive to corrosion. However, control of lube oil contaminants may not always have been adequate to preclude corrosion. Therefore, the effectiveness of lubricating oil control should be verified to ensure that corrosion is not occurring. The GALL Report recommends further evaluation of programs to manage corrosion to verify the effectiveness of the lubricating oil program. A one-time inspection of selected components at susceptible locations is an acceptable method to ensure that corrosion is not occurring and that the components intended function will be maintained during the period of extended operation. | |||
In addition, corrosion may occur at locations in the reactor coolant pump oil collection tank where water from wash downs may accumulate. Therefore, the effectiveness of the program should be verified to ensure that corrosion is not occurring. The GALL Report recommends further evaluation of programs to manage loss of material due to general, pitting, and crevice corrosion, to include determining the thickness of the lower portion of the tank. A one-time inspection is an acceptable method to ensure that corrosion is not occurring and that the components intended function will be maintained during the period of extended operation. | |||
: | : 2. Loss of material due to general, pitting, and crevice corrosion could occur in steel piping, piping components, and piping elements in the BWR reactor water cleanup and shutdown cooling systems exposed to treated water. The existing aging management program relies on monitoring and control of reactor water chemistry to manage the aging effects of loss of material from general, pitting and crevice corrosion. However, high concentrations of impurities at crevices and locations of stagnant flow conditions could cause general, pitting, or crevice corrosion. Therefore, the effectiveness of the chemistry control program should be verified to ensure that corrosion is not occurring. The GALL Report recommends further evaluation of programs to manage loss of material from general, pitting, and crevice corrosion to verify the effectiveness of the water chemistry program. A one-time inspection of select components at susceptible locations is an acceptable method to ensure that corrosion is not occurring and that the components intended function will be maintained during the period of extended operation. | ||
: 3. Loss of material due to general (steel only) pitting and crevice corrosion could occur for steel and stainless steel diesel exhaust piping, piping components, and piping elements exposed to diesel exhaust. The GALL Report recommends further evaluation of a plant-specific aging management program to ensure that these aging effects are adequately managed. | |||
Acceptance criteria are described in Branch Technical Position RLSB-1 (Appendix A.1 of this SRP-LR.) | |||
September 2005 3.3-5 NUREG-1800, Rev. 1 | |||
3.3.3.2.6 Reduction of Neutron | - D monitoring of the shell side water, and eddy current testing of tubes. The reviewer reviews the applicants proposed program on a case-by-case basis to ensure that an adequate program will be in place for the management of these aging effects. | ||
-Absorbing Capacity and Loss of Material due to General Corrosion | : 2. The GALL Report recommends further evaluation of programs to manage cracking due to SCC and cyclic loading in the stainless steel PWR regenerative heat exchanger components exposed to treated borated water greater than 60°C (>140°F). The water chemistry program relies on monitoring and control of water chemistry to manage the aging effects of cracking due to SCC and cyclic loading. The GALL Report recommends the effectiveness of the chemistry control program be verified to ensure that cracking is not occurring. The absence of cracking due to SCC and cyclic loading is to be verified. The reviewer reviews the applicants proposed program on a case-by-case basis to ensure that an adequate program will be in place for the management of these aging effects. | ||
-absorbing capacity and loss of material due to general corrosion of the neutron | : 3. The GALL Report recommends further evaluation of programs to manage cracking due to cyclic loading for the stainless steel pump casing of high-pressure pumps in the PWR chemical and volume control system. The GALL Report recommends further evaluation to ensure that these aging effects are adequately managed. The reviewer reviews the applicants proposed program on a case-by-case basis to ensure that an adequate program will be in place for the management of these aging effects. | ||
-absorbing sheets in BWR and PWR spent fuel storage racks. The reviewer reviews the | 3.3.3.2.5 Hardening and Cracking or Loss of Strength due to Elastomer Degradation | ||
-by-case basis to ensure that an adequate program will be in place for the management of these aging effects. | : 1. The GALL Report recommends further evaluation of programs to manage the Hardening and loss of strength due to elastomer degradation could occur in elastomer seals and components of heating and ventilation systems exposed to air - indoor uncontrolled (internal/external. The reviewer reviews the applicants proposed program on a case-by-case basis to ensure that an adequate program will be in place for the management of these aging effects. | ||
3.3.3.2.7 Loss of Material due to General, Pitting, and Crevice Corrosion | : 2. The GALL Report also recommends further evaluation of programs to manage the hardening and cracking due to elastomer degradation of valves in spent fuel pool cooling and cleanup system (BWR and PWR). The reviewer reviews the applicants proposed program on a case-by-case basis to ensure that an adequate program will be in place for the management of these aging effects. | ||
: 1. The GALL Report recommends further evaluation of programs to manage the loss of material due to general, pitting, and crevice corrosion of steel piping, piping components, and piping elements exposed to lubricating oil, including the tanks, valve bodies, and tubing in the reactor coolant pump oil collection system (as part of the fire protection system). The | 3.3.3.2.6 Reduction of Neutron-Absorbing Capacity and Loss of Material due to General Corrosion The GALL Report recommends further evaluation of programs to manage reduction of neutron-absorbing capacity and loss of material due to general corrosion of the neutron-absorbing sheets in BWR and PWR spent fuel storage racks. The reviewer reviews the applicants proposed program on a case-by-case basis to ensure that an adequate program will be in place for the management of these aging effects. | ||
3.3.3.2.7 Loss of Material due to General, Pitting, and Crevice Corrosion | |||
: 1. The GALL Report recommends further evaluation of programs to manage the loss of material due to general, pitting, and crevice corrosion of steel piping, piping components, and piping elements exposed to lubricating oil, including the tanks, valve bodies, and tubing in the reactor coolant pump oil collection system (as part of the fire protection system). The NUREG-1800, Rev. 1 3.3-12 September 2005 | |||
3.3.2.2.5.1) Yes, plant specific (See subsection | Table 3.3-1. Summary of Aging Management Programs for Auxiliary Systems Evaluated in Chapter VII of the GALL Report ID Type Component Aging Aging Management Further Evaluation Related Effect/Mechanism Programs Recommended Item 11 BWR/ Elastomer seals and Hardening and loss of A plant specific aging Yes, plant specific A-17 PWR components exposed to air - strength due to elastomer management program is to (See subsection indoor uncontrolled degradation be evaluated. 3.3.2.2.5.1) | ||
NUREG-1800, Rev. 1 (internal/external) 12 BWR/ Elastomer lining exposed to Hardening and loss of A plant specific aging Yes, plant specific A-15 PWR treated water or treated borated strength due to elastomer management program is to (See subsection A-16 water degradation be evaluated. 3.3.2.2.5.2) 13 BWR/ Boral, boron steel and other Reduction of neutron- A plant specific aging Yes, plant specific A-88 PWR materials (excluding Boraflex) absorbing capacity, management program is to (See subsection A-89 utilized as neutron absorbers in changes in dimension be evaluated. Monitoring of 3.3.2.2.6)No spent fuel storage racks neutron- that increase Keff, and Neutron-Absorbing Materials absorbing sheets exposed to loss of material due to other than Boraflex treated water or treated borated neutron-absorber water degradation and radiationgeneral 3.3-22 corrosion - D 14 BWR/ Steel piping, piping component, Loss of material due to Lubricating Oil Analysis and Yes, detection of AP-30 PWR and piping elements exposed to general, pitting, and One-Time Inspection aging effects is to be lubricating oil crevice corrosion evaluated (See subsection 3.3.2.2.7.1) 15 BWR/ Steel reactor coolant pump oil Loss of material due to Lubricating Oil Analysis and Yes, detection of A-83 PWR collection system piping, tubing, general, pitting, and One-Time Inspection aging effects is to be and valve bodies exposed to crevice corrosion evaluated (See lubricating oil subsection 3.3.2.2.7.1) 16 BWR/ Steel reactor coolant pump oil Loss of material due to Lubricating Oil Analysis and Yes, detection of A-82 PWR collection system tank exposed general, pitting, and One-Time Inspection to aging effects is to be to lubricating oil crevice corrosion evaluate the thickness of the evaluated (See lower portion of the tank subsection 3.3.2.2.7.1) 17 BWR Steel piping, piping components, Loss of material due to Water Chemistry and One- Yes, detection of A-35 and piping elements exposed to general, pitting, and Time Inspection aging effects is to be treated water crevice corrosion evaluated (See subsection September 2005 3.3.2.2.7.2) | |||
3.3. | - D Table 3.3-2. FSAR Supplement for Aging Management of Auxiliary Systems Implementation Program Description of Program Schedule* | ||
Inspection of Internal The program visually inspects internal surfaces of Existing program Surfaces in Miscellaneous steel piping, piping elements, ducting, and Piping and Ducting components in an internal environment (indoor Components uncontrolled air, condensation, and steam) that (BWR/PWR) are not included in other aging management programs, for loss of material. Inspections are performed when the internal surfaces are accessible during the performance of periodic surveillance tests, during preventive maintenance activities or during scheduled outages. The program includes visual inspection to assure that existing environment conditions are not causing material degradation that could result in a loss of system intended functions. | |||
Inspection of Overhead The program evaluates the effectiveness of the Existing program Heavy Load and Light maintenance monitoring program and the effects Load Handling System of past and future usage on the structural reliability of cranes and hoists. The number and magnitude of lifts made by the hoist or crane are also reviewed. Rails and girders are visually inspected on a routine basis for degradation. | |||
Functional tests are also performed to assure their integrity. These cranes must also comply with the maintenance rule requirements provided in 10 CFR 50.65. | |||
Lubricating Oil Analysis This program ensures the oil environment in the Existing program mechanical systems is maintained to the required quality. The program maintains oil systems free of contaminants (primarily water and particulates) thereby preserving an environment that is not conducive to loss of material, cracking, or reduction of heat transfer. Lubricating oil testing activities include sampling and analysis of lubricating oil for detrimental contaminants. The presence of water or particulates may also be indicative of inleakage and corrosion product buildup. | |||
Monitoring of Neutron- The program is implemented to assure that Program should Absorbing Materials other degradation of spent fuel pool neutron-absorbing be implemented than Boraflex material that could compromise the criticality before the period analysis will be detected in the period of extended of extended operation. The loss of material and the operation. | |||
degradation of the neutron-absorbing material capacity are determined through coupon testing, direct in situ testing, or both. Such testing includes periodic verification of boron loss through areal density measurement of coupons or through direct in situ techniques, such as measurement of boron areal density, measurement of geometric changes in the material (blistering, pitting, and bulging), | |||
and detection of gaps through blackness testing. | |||
September 2005 3.3-39 NUREG-1800, Rev. 1 | |||
3.3 | - D One-Time Inspection This program verifies the effectiveness of other The inspection aging management program by determining if the should be aging effect is not occurring or the aging effect is completed progressing slowly so that the intended function before the period will be maintained during the period of extended of extended operation. operation. | ||
September 2005 3.3-39 NUREG-1800, Rev. 1 | |||
3.3. | Table 3. Summary of Aging Management Programs for the Auxiliary Systems Evaluated in Chapter VII of the GALL Report Further Related Aging Aging Management Unique ID Type Component Evaluation Generic Effect/Mechanism Programs Item Recommended Item 13 BWR/ Boral, boron steel and other Reduction of neutron- Plant specific Monitoring Yes, plant A-88 VII.A2-5 PWR materials (excluding absorbing capacity, of Neutron-Absorbing specificNo A-89 VII.A2-3 Boraflex) utilized as neutron changes in dimension Materials other than absorbers in spent fuel that increase Keff, Boraflex storage racks neutron- and loss of material NUREG-1801 Vol. 1, Rev. 1 absorbing sheets exposed to due to neutron-treated water or treated absorber degradation borated water and radiationgeneral corrosion 14 BWR/ Steel piping, piping Loss of material due to Lubricating Oil Analysis Yes, detection of AP-30 VII.C1-17 PWR component, and piping general, pitting, and and One-Time Inspection aging effects is to VII.C2-13 48 elements exposed to crevice corrosion be evaluated VII.E1-19 | ||
- D lubricating oil VII.E4-16 VII.F1-19 VII.F2-17 VII.F3-19 VII.F4-15 VII.G-22 VII.H2-20 15 BWR/ Steel reactor coolant pump Loss of material due to Lubricating Oil Analysis Yes, detection of A-83 VII.G-26 PWR oil collection system piping, general, pitting, and and One-Time Inspection aging effects is to tubing, and valve bodies crevice corrosion be evaluated exposed to lubricating oil 16 BWR/ Steel reactor coolant pump Loss of material due to Lubricating Oil Analysis Yes, detection of A-82 VII.G-27 PWR oil collection system tank general, pitting, and and One-Time Inspection aging effects is to exposed to lubricating oil crevice corrosion to evaluate the thickness be evaluated of the lower portion of the tank 17 BWR Steel piping, piping Loss of material due to Water Chemistry and Yes, detection of A-35 VII.E3-18 September 2005 components, and piping general, pitting, and One-Time Inspection aging effects is to VII.E4-17 elements exposed to treated crevice corrosion be evaluated water | |||
VII AUXILIARY SYSTEMS A2 Spent Fuel Storage Structure Aging Effect/ Further Item Link and/or Material Environment Aging Management Program (AMP) | |||
Mechanism Evaluation Component VII.A2-1 VII.A2. Piping, piping Stainless Treated Loss of material/ Chapter XI.M2, Water Chemistry, No NUREG-1801, Rev. 1 components, Steel; Steel borated water pitting and for PWR primary water (AP-79) and piping with crevice corrosion elements stainless steel cladding VII.A2-2 VII.A2.1-a Spent fuel Boraflex Treated water Reduction of Chapter XI.M22, Boraflex No storage racks neutron- Monitoring (A-87) absorbing Neutron- capacity/ boraflex absorbing degradation sheets - | |||
BWR | |||
- D VII A2-2 VII.A2-3 VII.A2.1-b Spent fuel Boral, Treated water Reduction of A plant-specific aging management Yes, plant-storage racks boron steel neutron- program is to be evaluated.Chapter specificNo (A-89) and other absorbing XI.M40, Monitoring of Neutron-Neutron- materials capacity, Absorbing Materials other than absorbing (excluding changes in Boraflex sheets - Boraflex) dimension that BWR utilized as increase Keff, neutron and loss of absorbers material due to neutron-absorber degradation and radiation/ general corrosion VII.A2-4 VII.A2.1-a Spent fuel Boraflex Treated Reduction of Chapter XI.M22, Boraflex No storage racks borated water neutron- Monitoring (A-86) absorbing Neutron- capacity/ boraflex absorbing degradation sheets - | |||
September 2005 PWR | |||
VII AUXILIARY SYSTEMS A2 Spent Fuel Storage Structure Aging Effect/ Further Item Link and/or Material Environment Aging Management Program (AMP) | |||
Mechanism Evaluation Component September 2005 VII.A2-5 VII.A2.1-b Spent fuel Boral, Treated Reduction of A plant-specific aging management Yes, plant-storage racks boron steel borated water neutron- program is to be evaluated.Chapter specificNo (A-88) and other absorbing XI.M40, Monitoring of Neutron-Neutron- materials capacity, Absorbing Materials other then absorbing (excluding changes in Boraflex sheets - Boraflex) dimension that PWR utilized as increase Keff, neutron and loss of absorbers material due to neutron-absorber degradation and radiation/ general corrosion VII A2-3 - D VII.A2-6 VII.A2.1-c Spent fuel Stainless Treated water Cracking/ stress Chapter XI.M2, Water Chemistry, No storage racks steel >60ºC corrosion for BWR water (A-96) (>140ºF) cracking Storage racks - BWR VII.A2-7 VII.A2.1-c Spent fuel Stainless Treated Cracking/ stress Chapter XI.M2, Water Chemistry, No storage racks steel borated water corrosion for PWR primary water (A-97) >60ºC cracking Storage (>140ºF) racks - PWR NUREG-1801, Rev. 1 | |||
- D XI.M40 MONITORING OF NEUTRON-ABSORBING MATERIALS OTHER THAN BORAFLEX Program Description A monitoring program is implemented to assure that degradation of the neutron-absorbing material used in spent fuel pools that could compromise the criticality analysis will be detected. | |||
- D | The applicable aging management program (AMP) relies on periodic inspection, testing, monitoring, and analysis of the criticality design to assure that the required five percent subcriticality margin is maintained during the renewed license period. | ||
Evaluation and Technical Basis | |||
: 1. Scope of Program: The AMP manages the effects of aging on neutron-absorbing components/materials used in spent fuel racks. | |||
- | : 2. Preventive Actions: This AMP is a condition monitoring program and therefore there are no preventative actions. | ||
: 3. Parameters Monitored/Inspected: For these materials, gamma irradiation and/or long-term exposure to the wet pool environment may cause shrinkage resulting in loss of material, and changes in dimension (such as gap formation, formation of blisters, pits and bulges) which could result in loss of neutron absorbing capability of the material. The parameters monitored include the physical condition of the neutron-absorbing materials, such as in situ gap formation, geometric changes in the material (formation of blisters, pits, and bulges) as observed from coupons or in situ, and decreased boron areal density, etc. The parameters monitored should be directly related to determination of the loss of material or loss of neutron absorption capability of the material(s). | |||
: 4. Detection of Aging Effects: The loss of material and the degradation of the neutron-absorbing material capacity are determined through coupon and/or direct in situ testing. | |||
Such testing should include periodic verification of boron loss through areal density measurement of coupons or through direct in situ techniques which may include measurement of boron areal density, geometric changes in the material (blistering, pitting, and bulging), and detection of gaps through blackness testing. The frequency of the inspection and testing depends on the condition of the neutron-absorbing material and should be determined and justified with plant-specific operating experience by the licensee, not to exceed 10 years. | |||
: 5. Monitoring and Trending: The measurements from periodic inspections and analysis are compared to baseline information or prior measurements and analysis for trend analysis. | |||
The approach for relating the measurements to the performance of the spent fuel neutron absorber materials shall be specified by the applicant, considering differences in exposure conditions, vented/non-vented test samples and spent fuel racks, etc. | |||
: 6. Acceptance Criteria: Although the goal is to ensure maintenance of the five percent subcriticality margin for the spent fuel pool, the specific acceptance criteria for the measurements and analyses shall be specified by the applicant. | |||
: 7. Corrective Actions: Corrective actions are initiated if the results from measurements and analysis indicate that the five percent subcriticality margin cannot be maintained because of September 2005 XI M-125 NUREG-1801, Rev. 1 | |||
- D the current or projected future degradation of the neutron-absorbing material. Corrective actions may consist of providing additional neutron-absorbing capacity with an alternate material, or applying other options, which are available to maintain the subcriticality margin. | |||
- D | As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B, acceptable to address the corrective actions. | ||
: 8. Confirmation Process: Site quality assurance (QA) procedures, site review and approval processes, and administrative controls are implemented in accordance with the requirements of 10 CFR Part 50, Appendix B. As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B acceptable to address the confirmation process and administrative controls. | |||
: 9. Administrative Controls: As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B, acceptable to address administrative controls. | |||
: 10. Operating Experience: Applicants for license renewal should reference plant-specific operating experience and industry experience to provide reasonable assurance that the program will be able to detect degradation of the neutron absorbing material in the applicants spent fuel pool. Some of the industry operating experience that should be included is listed below: | |||
: 8. Confirmation Process | |||
: Site quality assurance (QA) procedures, site review and approval processes, and administrative controls are implemented in accordance with the requirements of 10 CFR Part 50, Appendix B. As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B acceptable to address the confirmation process and administrative controls. | |||
: 9. Administrative Controls | |||
: As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B, acceptable to address administrative controls. | |||
: 10. Operating Experience | |||
: Applicants for license renewal should reference plant-specific operating experience and industry experience to provide reasonable assurance that the program will be able to detect degradation of the neutron absorbing material in the | |||
: 1. Loss of material from the neutron absorbing material has been seen at many plants, including loss of aluminum which was detected by monitoring the aluminum concentration in the spent fuel pool. One instance of this was documented in the Vogtle LRA Water Chemistry Program B.3.28. | : 1. Loss of material from the neutron absorbing material has been seen at many plants, including loss of aluminum which was detected by monitoring the aluminum concentration in the spent fuel pool. One instance of this was documented in the Vogtle LRA Water Chemistry Program B.3.28. | ||
: 2. Blistering has also been noted at many plants. Examples include blistering at Seabrook and Beaver Valley. | : 2. Blistering has also been noted at many plants. Examples include blistering at Seabrook and Beaver Valley. | ||
: 3. The significant loss of neutron-absorbing capacity of the plate-type carborundum material has been reported at Palisades. | : 3. The significant loss of neutron-absorbing capacity of the plate-type carborundum material has been reported at Palisades. | ||
The applicant should describe how the monitoring program described above is capable of detecting the aforementioned degradation mechanisms. | The applicant should describe how the monitoring program described above is capable of detecting the aforementioned degradation mechanisms. | ||
References Letter from Christopher J. Schwarz, Entergy Nuclear Operations, Inc., Palisades Nuclear Plant, to the U.S. Nuclear Regulatory Commission, Commitments to Address Degraded Spent Fuel Pool Storage Rack Neutron Absorber , August 27, 2008, (ADAMS Accession No. ML082410132). | References Letter from Christopher J. Schwarz, Entergy Nuclear Operations, Inc., Palisades Nuclear Plant, to the U.S. Nuclear Regulatory Commission, Commitments to Address Degraded Spent Fuel Pool Storage Rack Neutron Absorber, August 27, 2008, (ADAMS Accession No. ML082410132). | ||
Letter from Kevin L. Ostrowski, FirstEnergy Nuclear Operating Company, to the U.S. Nuclear Regulatory Commission, Supplemental Information for the Review of the Beaver Valley Power Station, Units 1 and 2, License Renewal Application (TAC Nos. MD6593 and MD6594) and License Renewal Application Amendment No. 34 , January 19, 2009, (ADAMS Accession No. ML090220216). | Letter from Kevin L. Ostrowski, FirstEnergy Nuclear Operating Company, to the U.S. Nuclear Regulatory Commission, Supplemental Information for the Review of the Beaver Valley Power Station, Units 1 and 2, License Renewal Application (TAC Nos. MD6593 and MD6594) and License Renewal Application Amendment No. 34, January 19, 2009, (ADAMS Accession No. ML090220216). | ||
Letter from Mark E. Warner, FPL Energy Seabrook Station, to the U.S. Nuclear Regulatory Commission, Seabrook Station Boral Spent Fuel Pool Test Coupons Report Pursuant to 10 CFR Part 21.21, October 6, 2003 (ADAMS Accession No. ML032880525). | Letter from Mark E. Warner, FPL Energy Seabrook Station, to the U.S. Nuclear Regulatory Commission, Seabrook Station Boral Spent Fuel Pool Test Coupons Report Pursuant to 10 CFR Part 21.21, October 6, 2003 (ADAMS Accession No. ML032880525). | ||
NUREG-1801, Rev. 1 XI M-126 September 2005 | |||
- D License Renewal Application Vogtle Electric Generating Plant Units 1 and 2, Southern Nuclear Operating Company, Inc., June 30, 2007 (ADAMS Accession No. ML071840360). | |||
September 2005 XI M-127 NUREG-1801, Rev. 1 | |||
APPENDIX E RESOLUTION OF PUBLIC COMMENTS ON DRAFT LR-ISG-2009-01 | |||
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.) | |||
Southern Nuclear Operating Company (SNC) takes The third paragraph under the Boral exception to the statement in the Discussion section, heading in the Discussion section has under the Boral heading, that, Similarly, the spent been revised to include the word may to fuel pool water chemistry program at Vogtle clarify that there is the possibility that an documented an increase in the concentration of increased aluminum concentration indicates aluminum, which indicates loss of material from the loss of the Boral neutron-absorbing Southern Nuclear Operating Boral neutron absorbing material (Ref. 7). SNC does material. | |||
Company, Inc. Letter dated 1 not believe that increasing aluminum concentration in December 17, 2009 the spent fuel pool water is conclusive evidence that Regarding the Vogtle Electric Generating (ML093570197) loss of material from the Boral neutron absorbing Plant operating experience, the increasing material is occurring. Therefore, it is inappropriate to aluminum concentration is an indication of use the Vogtle Electric Generating Plant operating degradation of the Boral cladding, which experience with aluminum concentration in the spent may indicate a larger problem. | |||
fuel pool as indication of degradation of the Boral neutron absorbing material. | |||
In item four, Detection of Aging Effects, under the In the aging management program Evaluation and Technical Basis heading of the description, the Detection of Aging Effects Exelon Generation attached aging management program, XI.XXXX item has been clarified to indicate that either Company, LLC Letter dated Monitoring of Neutron Absorbing Materials other than coupon testing or direct in situ testing, or 2 | |||
December 28, 2009 Boraflex, clarify the intent of the requirement to both, may be used to detect the aging (ML100060388) specify whether in situ testing methods can be used in effects of concern. | |||
lieu of coupon measurements, or if both are required in lieu of the alternate methods listed. | |||
In item ten, Operating Experience, under the In the aging management program Evaluation and Technical Basis heading of the description, the Operating Experience item Exelon Generation attached aging management program, XI.XXXX has been clarified to reflect the Palisades Company, LLC Letter dated Monitoring of Neutron Absorbing Materials other than Nuclear Plant operating experience 3 | |||
December 28, 2009 Boraflex, the listed operating experience includes the concerning the plate-type carborundum (ML100060388) loss of neutron-absorbing capacity of the material at material. | |||
the Palisades plant. Please clarify that material for this example was carborundum and not Boral. | |||
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.) | |||
Clarify in the LR-ISG that if the neutron absorber is Some clarifications have been made as not credited in the licensees' criticality analysis, then a discussed in the response to Comment surveillance program for that neutron absorber is not No. 11. No other changes to the LR-ISG Nuclear Energy Institute required. are necessary because neutron absorbers Letter dated December 31, 4 not credited in the applicant's criticality 2009 analysis are not within the scope of license (ML100060387) renewal, as defined in 10 CFR 54.4. | |||
Therefore, an aging management review of such components is not required. | |||
The LR-ISG does not provide a viable option for those No changes to the LR-ISG have been licensees that do not have a coupon testing program. incorporated. The NRCs staffs intent is not Nuclear Energy Institute The LR-ISG would require the performance of to recommend "continuous" testing, but Letter dated December 31, 5 continuous neutron absorber areal density rather periodic coupon or in situ testing. | |||
2009 measurements (blackness testing). Provide a viable (ML100060387) alternative to continuous blackness testing for the effected licensees. | |||
Consider the addition of allowing licensees to No changes to the LR-ISG have been demonstrate that the combination of the neutron incorporated. The LR-ISG provides absorber manufacturing process, spent fuel pool guidance as to one acceptable approach for environment and previous/existing testing provides managing the effects of aging during the Nuclear Energy Institute reasonable assurance of the continued efficacy of the period of extended operation for certain Letter dated December 31, 6 neutron absorber capability in lieu of a testing neutron-absorbing spent fuel pool 2009 program. components; however, this guidance does (ML100060387) not preclude a license renewal applicant from proposing and justifying other approaches for managing the effects of aging. | |||
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.) | |||
The Discussion section, under the Carborundum Comment incorporated. | |||
heading states: The swelling of the racks, which prevents fuel assemblies from being inserted or removed, indicates a potential problem with neutron-absorbing capacity. However, swelling of racks does Nuclear Energy Institute not necessarily provide an indication of a loss of Letter dated December 31, 7 neutron absorption capacity. Root cause evaluations 2009 have not provided a clear link between swelling and (ML100060387) the loss of neutron absorption. Therefore, change this sentence to: The swelling of the racks, which prevents fuel assemblies from being inserted or removed, may indicate a potential problem with neutron-absorbing capacity. | |||
In the Discussion section, under the Carborundum A clarification has been made in the subject heading, clarify that another form of carborundum paragraph to indicate that the discussion Nuclear Energy Institute does exist and it has not experienced similar concerns only plate-type carborundum. | |||
Letter dated December 31, 8 degradation mechanisms to that of the plate type 2009 carborundum found at Palisades. Add the sentence, (ML100060387) | |||
This only applies to the plate type Carborundum, to the end of the second paragraph under this heading. | |||
On page four, under the heading, GALL Report, No changes to the LR-ISG have been Vol. 2, revise the Table VII.A2 to allow credit for incorporated. An appropriate technical Nuclear Energy Institute water chemistry in managing the aging effect of loss basis to support incorporation of this Letter dated December 31, of material by adding a line item to reference the comment has not been provided. The staff 9 | |||
2009 aging management program in GALL Report, has found that a surveillance program, as (ML100060387) Volume 2, Section XI.M2, Water Chemistry. described in the aging management program, is necessary for managing aging in this area. | |||
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.) | |||
- E | On page five, under the heading, SRP-LR, change The LR-ISG reflects changes to the aging the last sentence to: Reduction of neutron-absorbing effect/mechanism description in the revised capacity, changes in dimension that increase Keff or SRP-LR Table 3.3-1, item 13, GALL Report, negatively affect criticality and loss of material due to Volume 1, Table 3, item 13, and GALL the effects of the SFP environment. This change Report, Volume 2, Table VII.A2, items would acknowledge that a decrease in Keff could VII.A2-3 and VII.A2-5, to include changes occur and is not prohibited. in dimension that increase Keff. The intent Nuclear Energy Institute of the LR-ISG is to provide guidance for Letter dated December 31, managing the detrimental effects of aging, 10 2009 and changes in dimension that decrease (ML100060387) Keff are not detrimental aging effects. | ||
The proposed language in the comment includes the text: or negatively affect criticality. For conciseness, this text was not incorporated because negative effects on criticality are the same as increases in Keff. | |||
For clarification purposes, change the revised The LR-ISG reflects changes to the component item descriptions under the headings, component description in the revised GALL Report, Vol. 1 and SRP-LR, to: Boral, boron SRP-LR Table 3.3-1, item 13, and GALL Nuclear Energy Institute steel and other materials (excluding Boraflex) utilized Report, Volume 1, Table 3, item 13, to Letter dated December 31, 11 as neutron absorbers in spent fuel storage racks, clarify that the materials are utilized as 2009 exposed to treated water or treated borated water and neutron absorbers. This change is also (ML100060387) radiation effect. reflected in the material descriptions in the revised GALL Report, Volume 2, Table VII.A2, items VII.A2-3 and VII.A2-5. | |||
For clarity, in item one, Scope of Program, under the Comment incorporated. | |||
- | Nuclear Energy Institute Evaluation and Technical Basis heading of the Letter dated December 31, attached aging management program, XI.XXXX 12 2009 Monitoring of Neutron Absorbing Materials other than (ML100060387) Boraflex, move the second sentence to item three, Parameters Monitored/Inspected. | ||
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.) | |||
In item three, Parameters Monitored/Inspected, No changes to the LR-ISG have been under the Evaluation and Technical Basis heading of incorporated. The LR-ISG provides the attached aging management program, XI.XXXX guidance as to one acceptable approach for Monitoring of Neutron Absorbing Materials other than managing the effects of aging during the Nuclear Energy Institute Boraflex, add the following sentence: Where it can period of extended operation for certain Letter dated December 31, 13 be shown that for a specific material and environment neutron-absorbing spent fuel pool 2009 test results are not site-specific, the use of shared components; however, this guidance does (ML100060387) industry coupon testing results is acceptable. not preclude a license renewal applicant from proposing and justifying other approaches for managing the effects of aging. | |||
In item four, Detection of Aging Effects, under the Comment incorporated. | |||
Evaluation and Technical Basis heading of the attached aging management program, XI.XXXX Monitoring of Neutron Absorbing Materials other than Boraflex, change the first sentence to: "The loss of material and the degradation of the neutron-absorbing material capacity are determined through coupon or in Nuclear Energy Institute situ testing. Such testing includes measurement of Letter dated December 31, 14 boron areal density, geometric changes in the material 2009 (blistering, pitting, and bulging), detection of gaps (ML100060387) through blackness testing, and periodic verification of boron loss through in-situ areal density measurements or coupon testing. This change clarifies that in situ or coupon testing is acceptable, it also eliminate the specific reference to BADGER testing so that it does not appear NRC is advocating a specific manufacturer's type of testing. | |||
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.) | |||
- E | Regarding item four, Detection of Aging Effects, The 10-year maximum period between under the Evaluation and Technical Basis heading of inspections ensures that at least one set of the attached aging management program, XI.XXXX inspection and testing results will be Monitoring of Neutron Absorbing Materials other than acquired during the period of extended Boraflex, provide the basis for a testing frequency of operation. This period is consistent with a maximum of 10 years. Use of operating experience current industry inservice inspection should be permitted to allow licensees to determine requirements for component inspections Nuclear Energy Institute the appropriate inspection frequency requirements. under 10 CFR 50.55a and the Section XI of Letter dated December 31, Therefore, delete the words, with a maximum of the American Society of Mechanical 15 2009 10 years from the last sentence of this item. Engineers Code. | ||
(ML100060387) | |||
Therefore, delete the words, | In the aging management program description, the Detection of Aging Effects item has been clarified to state that applicants should determine and justify the inspection and testing frequency based on operating experience; however, this frequency is not to exceed 10 years. | ||
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.) | |||
Concerning the second sentence of item seven, Comment incorporated. | |||
- E | Corrective Actions, under the Evaluation and Technical Basis heading of the attached aging management program, XI.XXXX Monitoring of Neutron Absorbing Materials other than Boraflex, (1) change Corrective actions consist of to: | ||
Corrective actions may consist of This change is to clarify that the licensees' corrective action process will determine the appropriate actions. Also, Nuclear Energy Institute Letter dated December 31, (2) those licensees with 10 CFR 50.68(b)(4) as their 16 2009 licensing basis comply with the regulatory requirement (ML100060387) that the spent fuel pool remain subcritical without soluble boron. Therefore, the five percent subcritical margin referred to is only applicable for normal conditions for those licensees. | |||
Given these two comments, change the second sentence of item seven to: "Corrective actions may consist of providing additional neutron-absorbing capacity with an alternate material, or applying other options, which are available to maintain the appropriate subcriticality margin. | |||
The term Carborundum is used rather than No changes to the LR-ISG have been something more generic. Carborundum is the incorporated. Carborundum is referenced manufacturer of a neutron-absorber which consists of in the LR-ISG either as an example of a boron-carbide in a phenol formaldehyde resin. Other neutron-absorbing material or in the Nuclear Energy Institute manufacturers (e.g., ESK) manufacture boron-carbide description of plant-specific operating 17 Email dated January 6, 2010 in a phenolic resin, which is a similar material. The experience for carborundum. | |||
(ML100280648) term carborundum is used throughout the document in a generic sense and it should only be used for those specific stations that have carborundum (e.g., | |||
Palisades). | |||
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.) | |||
The LR-ISG uses the term, Region 1 Fuel Storage The definition or region 1 racks has been Racks. This is specific rack defined by a specific clarified as high reactivity, unburned reload Nuclear Energy Institute station. This term should be better defined, for fuel, as defined in Electric Power Research 18 Email dated January 6, 2010 example, use fuel storage racks that receive freshly Institutes Handbook of Neutron Absorber (ML100280648) discharged fuel, or something similar. Materials for Spent Fuel Transportation and Storage Applications, dated 2006.}} | |||
- E |
Latest revision as of 22:17, 13 November 2019
ML100621321 | |
Person / Time | |
---|---|
Issue date: | 04/27/2010 |
From: | Office of Nuclear Reactor Regulation |
To: | Eysymontt G, Keys J Nuclear Energy Institute |
Homiack M, NRR/DLR, 415-1683 | |
Shared Package | |
ML100630027 | List: |
References | |
LR-ISG-2009-01 | |
Download: ML100621321 (39) | |
Text
FINAL LICENSE RENEWAL INTERIM STAFF GUIDANCE LR-ISG-2009-01 AGING MANAGEMENT OF SPENT FUEL POOL NEUTRON-ABSORBING MATERIALS OTHER THAN BORAFLEX INTRODUCTION This final license renewal interim staff guidance (LR-ISG) LR-ISG-2009-01, Aging Management of Spent Fuel Pool Neutron-Absorbing Materials other than Boraflex, provides guidance as to one acceptable approach for managing the effects of aging during the period of extended operation for certain neutron-absorbing spent fuel pool components within the scope of the License Renewal Rule (Title 10 of the Code of Federal Regulations, Part 54, Requirements for Renewal of Operating Licenses for Nuclear Power Plants (10 CFR Part 54)). This LR-ISG recommends an aging management program (AMP) to address the potential loss of material and loss of neutron-absorbing capability of these components during the period of extended operation. A license renewal applicant may reference this AMP in its license renewal application (LRA) to demonstrate that the programs at its facility are acceptable to the U.S.
Nuclear Regulatory Commission (NRC or the staff) for compliance with the License Renewal Rule, until the guidance in this final LR-ISG is implemented into the next update of the license renewal guidance documents. This LR-ISG does not apply to Boraflex, for which Section XI.M22, Boraflex Monitoring, of the Generic Aging Lessons Learned (GALL) Report (NRC, 2005a) describes adequate AMP characteristics.
DISCUSSION Pursuant to 10 CFR 54.21, a license renewal applicant is required to demonstrate that the effects of aging on structures and components subject to an aging management review (AMR) will be adequately managed so that the intended functions will be maintained consistent with the current licensing basis for the period of extended operation. The Standard Review Plan for Review of License Renewal Applications for Nuclear Power Plants (SRP-LR) (NRC, 2005b) provides guidance to the staff reviewers performing safety reviews of applications to renew nuclear power plant licenses in accordance with 10 CFR Part 54. SRP-LR Section 3.3.2.2.6 provides acceptance criteria for spent fuel pool neutron-absorbing materials subject to an AMR.
Licensees use many neutron-absorbing materials in spent fuel pools, such as Boraflex, Boral, Metamic, boron steel, and carborundum. As previously mentioned, the GALL Report describes adequate AMP characteristics for Boraflex monitoring; however, management of the aging effects of the other materials has generally not been adequately addressed in current guidance.
Recent operating experience indicates several instances of degradation and/or deformation of neutron-absorbing materials in the spent fuel pools of operating reactors, as described in NRC Information Notice 2009-26, Degradation of Neutron-Absorbing Materials in the Spent Fuel Pool (NRC, 2009a). Operating experience related to two specific spent fuel pool neutron-absorbing materials is described in the following sections.
Carborundum In July 2008, the licensee of Palisades Nuclear Plant discovered that the region 1 fuel storage rack contained less neutron-absorbing material than assumed in the spent fuel pool criticality analysis of record (Entergy Nuclear Operations, Inc., 2008). The Electric Power Research Institute (EPRI) defines region 1 fuel storage racks as those that receive high reactivity, unburned reload fuel (EPRI, 2006). The lack of neutron-absorbing material resulted in noncompliance with the spent fuel pool criticality requirements in Technical Specification 4.3.1.1.b. In response to this concern, the licensee performed blackness testing of the region 1 spent fuel pool racks to validate that the racks would continue to perform neutron attenuation as credited in the licensees criticality analysis of record and to satisfy regulatory requirements and renewed license commitments.
The licensee performed in situ Boron-10 Areal Density Gauge for Evaluating Racks (BADGER) testing of approximately two percent of the storage locations, which revealed that the Boron-10 areal density of the spent fuel pool racks was, at a minimum, approximately one-third of its original design value. The neutron-absorbing material, plate-type carborundum, which is relied on to maintain subcriticality in the spent fuel pool, was much less effective than assumed in the criticality analysis. Therefore, region 1 of the spent fuel pool no longer met the requirements of 10 CFR 50.68, Criticality Accident Requirements, or Technical Specification 4.3.1.1.b, which require that K-effective (Keff) for region 1 fuel racks be less than or equal to 0.95 if fully flooded with unborated water.
The licensee determined that the apparent cause of the degradation of the carborundum B4C plates was the spent fuel pool environment. The exact degradation mechanism or mechanisms are not clearly understood, but likely involve changes in the physical properties of the carborundum B4C plates that occur during prolonged exposure to the spent fuel pool environment. The swelling of the racks, which prevents fuel assemblies from being inserted or removed, may indicate a potential problem with neutron-absorbing capacity. The swelling in the racks could result from dimensional changes of the carborundum, which may be replaced by a gas-filled space, and could challenge the assumptions of the criticality analysis. This degradation may have been occurring as early as 1988 when the first impedance to inserting a fuel assembly was documented at Palisades Nuclear Plant. Since there was no surveillance of the neutron-absorbing capacity of the material, the start of the degradation and the degradation rate are unknown.
Boral An LRA supplement (FirstEnergy Nuclear Operating Company, 2009) indicates that inspections of the Boral neutron-absorber material coupons at the Beaver Valley Power Station in 2007 identified numerous blisters of the aluminum cladding, while only a few small blisters were identified in 2002. In region 1 fuel storage racks, blisters can displace water from the flux traps between storage cells and challenge dimensional assumptions used in the criticality analysis.
Based on these inspections, the licensee for Beaver Valley Power Station determined that the blistering of Boral aluminum cladding was an aging effect and that it would credit the existing Boral Surveillance Program for management of this aging. In addition, blistering of Boral neutron-absorbing material has also been observed at Seabrook Station (FPL Energy Seabrook Station, 2003).
In a letter responding to a staff request for additional information (PPL Susquehanna, LLC, 2009), the licensee for Susquehanna Steam Electric Station stated that it identified a significant
bulge in a poison can wall. Although the licensee did not definitively determine the cause of the bulge, its letter states that it may be the result of hydrogen gas generation from either moisture contained in the Boral at the time of manufacture or a leaking seal weld in the poison can. This bulge prevented the placement of a blade guide into the deformed cell.
Also, Section B.3.28, Water Chemistry Control Program of the LRA for Vogtle Electric Generating Plant (Southern Nuclear Operating Co., Inc (SNC), 2007) states that the spent fuel pool water chemistry program showed an increase in the concentration of aluminum, which may indicate loss of material from the Boral neutron-absorbing material.
Further, an Electric Power Research Institute report (EPRI, 2006), states the following concerning Boral:
in-pool blistering of BORAL' has, to date, proved to be primarily an esthetic effect; however, the potential effects on fuel assembly clearance and the reactivity state of Region 1 racks have been noted. In addition, it has been noted that, in a few instances, rack cell wall deformation has occurred making it difficult to remove fuel. With plant life extension now the norm at most [light water reactors] in the US, some BORAL', which originally had a design service life of 40 years, will be in service more than 60 years. This suggests a prudent course is continued vigilance and surveillance so that onset of any degradation can be detected early and appropriate mitigation measures applied.
ACTION The recent instances of degradation and deformation of spent fuel pool neutron-absorbing materials, as discussed above, have led the staff to re-evaluate the SRP-LR and GALL Report guidance in this area. Based on the operating experience and other industry information, the staff has identified that the current license renewal guidance documents do not provide sufficient guidance to address the information that should be included in an LRA to demonstrate adequate management of the potential loss of material and loss of neutron-absorbing capability of the neutron-absorber material in spent fuel pools for the period of extended operation. As such, the staff has determined that the existing guidance requires clarification to address that, for each type of neutron-absorber material used in the applicants spent fuel pool(s), the applicant should demonstrate in their specific spent fuel pool environment for their specific material(s) that degradation has not occurred in a manner that could adversely impact the materials intended function. The staff has also developed a generic AMP, Monitoring of Neutron-Absorbing Materials other than Boraflex, that is recommend for managing the aging effects associated with these spent fuel pool neutron-absorbing materials.
Necessary revisions to the various license renewal guidance documents are in Appendix A, Revisions to SRP-LR, Appendix B, Revisions to GALL Report, Volume 1, and Appendix C, Revisions to GALL Report, Volume 2. Appendix D, Mark-Up Showing Changes to the License Renewal Guidance Documents, shows these revisions as compared to the current license renewal guidance documents. An overview of these changes is discussed below.
In the GALL Report, the generic AMP referenced above will be included under a new Section XI.M40 in GALL Report, Volume 2. Aging management of spent fuel pool neutron-absorbing materials other than Boraflex is addressed under two specific line items, VII.A2-3 and VII.A2-5, in GALL Report, Volume 2. These items currently recommend a plant-specific AMP and further evaluation. However, since the staff has determined that the new generic program
is adequate for managing the associated aging effects with no further evaluation recommended, a plant-specific program is no longer recommended and corresponding changes the line items Aging Management Program (AMP) and Further Evaluation descriptions are necessary. In addition, the staff has determined that the Material and Aging Effect/Mechanism descriptions for these line items require clarification. Changes to the GALL Report, Volume 1, Table 3 summary item (identification number 13) related to these two line items are also necessary to reflect the changes to GALL Report, Volume 2. The final changes to the GALL Report are in Appendices B and C.
Several changes are also necessary to the SRP-LR. Due to the staffs determination that the new generic AMP is adequate for managing the aging effects with no further plant-specific evaluation recommended, the acceptance criteria and review procedures in SRP-LR Sections 3.3.2.2.6 and 3.3.3.2.6, respectively, are no longer necessary. Revisions to SRP-LR Table 3.3-1 are also necessary for consistency with the changes to Table 3 of GALL Report, Volume 1. In addition, an example final safety analysis report supplement for the new AMP needs to be added to SRP-LR Table 3.3-2. The final changes to the SRP-LR are in Appendix A.
The staff also notes that applicants should consider both plant-specific and industry operating experience in the LRA. The applicants plant-specific operating experience should be based on either data from on-going inspection and/or monitoring programs, or from other operational findings. The use of test data that does not bound the age of the material at the end of the period of extended operation is not sufficient since there is not sufficient evidence that extrapolation or accelerated testing is valid in these cases. For instance, the licensee for the Palisades Nuclear Plant extrapolated data through the period of extended operation which projected that no significant degradation was to be expected, but a surveillance inspection revealed unexpected degradation of the neutron-absorbing capacity of plate-type carborundum.
If the applicant has a surveillance program in place for the material, a description of the program and results can be applied to the AMR as operating experience. This program should provide reasonable assurance that the material will be properly managed and that future degradation will be detected in the period of extended operation. In addition, continuation of an on-going coupon inspection program is adequate, but if there is no on-going coupon sample program, then the LRA will need to propose a new inspection program.
The guidance in this final LR-ISG is approved for use by the staff and stakeholders. On December 1, 2009, the staff issued a Federal Register notice (NRC, 2009b) to request public comments on draft LR-ISG-2009-01, Staff Guidance Regarding Plant-Specific Aging Management Review and Aging Management Program for the Neutron-Absorber Material in the Spent Fuel Pool Associated with License Renewal Applications. In response, by letters dated December 17, 2009 (SNC, 2009), and December 28, 2009 (Exelon Generation Company, LLC, 2009), the NRC received comments from SNC and Exelon Generation Company, LLC, respectively. The NRC also received comments form the Nuclear Energy Institute (NEI) by letter dated December 31, 2009 (NEI, 2009a), and by email dated January 6, 2010 (NEI, 2010).
The NRC staff considered these comments in developing the final LR-ISG-2009-01. The staffs responses to these comments are in Appendix E, Resolution of Public Comments on Draft LR-ISG-2009-01. The title of the LR-ISG has been changed from the draft title, Staff Guidance Regarding Plant-Specific Aging Management Review and Aging Management Program for the Neutron-Absorber Material in the Spent Fuel Pool Associated with License Renewal Applications, to the final, Aging Management of Spent Fuel Pool Neutron-Absorbing Materials other than Boraflex, to clarify that this LR-ISG provides guidance concerning generic, not plant-specific, aging management recommendations.
BACKFITTING DISCUSSION This LR-ISG contains guidance as to one acceptable approach for managing the effects of aging during the period of extended operation for certain spent fuel pool neutron-absorbing materials within the scope of license renewal. Set forth below is the staff's discussion on:
(i) whether this LR-ISG addresses newly identified systems, structures, or components (SSCs) subject to aging management under 10 CFR 54.37(b), and (ii) compliance with the requirements of the Backfit Rule, 10 CFR 50.109.
Newly Identified SSCs under 10 CFR 54.37(b)
The NRC is not proposing to treat neutron-absorbing materials (other than Boraflex) in the spent fuel pools as newly identified SSCs under 10 CFR 54.37(b). Therefore, any additional action on such materials which the NRC may impose upon current holders of renewed operating licenses under 10 CFR Part 54 would not fall within the scope of 10 CFR 54.37(b). The NRC would have to address compliance with the requirements of 10 CFR 50.109, before it may impose any new aging management requirements for these neutron absorbing materials on current holders of renewed operating licenses (see discussion below).
Compliance with the Backfit Rule Issuance of this LR-ISG does not constitute backfitting as defined in 10 CFR 50.109(a)(1), and the NRC staff did not prepare a backfit analysis for issuing this LR-ISG. There are several rationales for this conclusion, depending upon the status of the nuclear power plant licensee.
Current operating license holders who have not applied for renewed licenses - This LR-ISG is not directed at holders of (original) operating licenses. Although the NRC is evaluating the issues identified in this LR-ISG for applicability to holders of original operating licenses, the NRC has not yet determined whether additional regulatory action must be initiated to address these issues. Any regulatory requirements imposed by the NRC as the result of this evaluation must be implemented consistent with the provisions of 10 CFR Part 50 and the Backfit Rule.
Therefore, issuance of this ISG does not constitute backfitting as applied to current holders of (original) operating licenses.
Licensees who are currently in the license renewal process - This LR-ISG is directed to current applicants for license renewal. However, this LR-ISG is not backfitting as defined in 10 CFR 50.109(a)(1). This guidance is non-binding and provides one approach acceptable to the NRC staff for managing the effects of aging of neutron-absorbing materials in the spent fuel pools in accordance with the requirements of 10 CFR Part 54. License renewal applicants are not required to use this guidance. Applicants may elect to propose an alternative approach for managing the aging of neutron-absorbing materials in spent fuel pools during the period of extended operation. In addition, the Backfit Rule does not protect license renewal applicants voluntarily requesting renewed licenses from changes in NRC requirements or guidance on license renewal prior to or during the pendency of their renewal application (NRC, 2008).
Therefore, issuance of this LR-ISG does not constitute backfitting as applied to current applicants for license renewal.
Licensees who already hold a renewed license - This guidance is also directed to licensees who already hold a renewed license. However, this guidance is non-binding and the LR-ISG does not require current holders of renewed licenses to take any action (i.e., programmatic or plant hardware changes for managing the aging of neutron-absorbing materials in spent fuel
pools). However, the NRC expects renewed license holders to review the information in this LR-ISG and consider actions consistent with this guidance as appropriate. If, in the future, the NRC decides to take additional action and impose requirements for management of neutron-absorbing materials in spent fuel pools, then the NRC will follow the requirements of the Backfit Rule.
REFERENCES 10 CFR Part 54, Requirements for Renewal of Operating Licenses for Nuclear Power Plants, Office of the Federal Register, National Archives and Records Administration, 2010.
10 CFR Part 50, Domestic Licensing of Production and Utilization Facilities, Office of the Federal Register, National Archives and Records Administration, 2010.
Electric Power Research Institute (EPRI). 2006. Handbook of Neutron Absorber Materials for Spent Fuel Transportation and Storage Applications. Palo Alto, CA. 1013721. (2006).
Entergy Nuclear Operations, Inc. 2008. Letter from Christopher J. Schwarz, Entergy Nuclear Operations, Inc., Palisades Nuclear Plant, to U.S. Nuclear Regulatory Commission, Commitments to Address Degraded Spent Fuel Pool Storage Rack Neutron Absorber.
(August 27, 2008). ADAMS No. ML082410132.
Exelon Generation Company, LLC. 2009. Letter from Patrick R. Simpson, Exelon Generation Company, LLC, to Michael Lesar, U.S. Nuclear Regulatory Commission, Comments on Draft License Renewal Interim Staff Guidance LR-ISG-2009-01. (December 28, 2009).
ADAMS No. ML100060388.
FirstEnergy Nuclear Operating Company. 2009. Letter from Kevin L. Ostrowski, FirstEnergy Nuclear Operating Company, to the U.S. Nuclear Regulatory Commission, Supplemental Information for the Review of the Beaver Valley Power Station, Units 1 and 2, License Renewal Application (TAC Nos. MD6593 and MD6594) and License Renewal Application Amendment No. 34. (January 19, 2009). ADAMS No. ML090220216.
FPL Energy Seabrook Station. 2003. Letter from Mark E. Warner, FPL Energy Seabrook Station, to the U.S. Nuclear Regulatory Commission, Seabrook Station Boral Spent Fuel Pool Test Coupons Report Pursuant to 10 CFR Part 21.21. (October 6, 2003).
ADAMS No. ML032880525.
Nuclear Energy Institute (NEI). 2009a. Letter from James H. Riley, NEI, to the Chief, Rulemaking, Directives, and Editing Branch, U.S. Nuclear Regulatory Commission, Proposed License Renewal Interim Staff Guidance LR-ISG-2009-01, Staff Guidance Regarding Plant-Specific Aging Management Review and Aging Management Program for Neutron-Adsorbing Material in Spent Fuel Pools. (December 31, 2009). ADAMS No. ML100060387.
Nuclear Energy Institute (NEI). 2010. Email from Julie Keys, NEI, to Ian Spivack, U.S. Nuclear Regulatory Commission, Fw: Draft LR-ISG-2009. (January 6, 2010). ADAMS No. ML100280648.
PPL Susquehanna, LLC. 2009. Letter from W. H. Spence, PPL Susquehanna, LLC, to the U.S.
Nuclear Regulatory Commission, Susquehanna Steam Electric Station Request for Additional Information for the Review of the Susquehanna Steam Electric Station Units 1 and 2, License Renewal Application (LRA) Section 3.3.2.2.6. (May 13, 2009). ADAMS No. ML091520031.
Southern Nuclear Operating Company, Inc. (SNC). 2007. License Renewal Application Vogtle Electric Generating Plant Units 1 and 2. (June 30, 2007). ADAMS No. ML071840360.
Southern Nuclear Operating Company, Inc. (SNC). 2009. Letter from M. J. Ajluni, Southern Nuclear Operating Company, Inc., to the U.S. Nuclear Regulatory Commission, Comments on Draft License Renewal Interim Staff Guidance, LR-ISG-2009-01: Staff Guidance Regarding Plant-Specific Aging Management Review and Aging Management Program for Neutron-Absorbing Material in Spent Fuel Pools (Docket ID NRC-2009-0521). (December 17, 2009). ADAMS No. ML093570197.
U.S. Nuclear Regulatory Commission (NRC). 2005a. Generic Aging Lessons Learned (GALL)
Report. Washington, D.C. NUREG-1801, Revision 1, Vols. 1 and 2. (September 2005).
ADAMS Nos. ML052770419 and ML052780376.
U.S. Nuclear Regulatory Commission (NRC). 2005b. Standard Review Plan for Review of License Renewal Applications for Nuclear Power Plants. Washington, D.C.
NUREG-1800, Revision 1. (September 2005). ADAMS No. ML052110007.
U.S. Nuclear Regulatory Commission (NRC). 2008. Memorandum from Dale E. Klein, Chairman, to Hubert T. Bell, Office of the Inspector General, Response to Recommendation 8 of 9/6/07 Audit Report on NRCs License Renewal Program.
(April 1, 2008). ADAMS No. ML080870286.
U.S. Nuclear Regulatory Commission (NRC). 2009a. Information Notice 2009-26, Degradation of Neutron-Absorbing Materials in the Spent Fuel Pool. (October 28, 2009). ADAMS No. ML092440545.
U.S. Nuclear Regulatory Commission (NRC). 2009b. Draft License Renewal Interim Staff Guidance LR-ISG-2009-01 Staff Guidance Regarding Plant-Specific Aging Management Review and Aging Management Program for the Neutron Absorber Material in the Spent Fuel Pool Associated with License Renewal Applications; Solicitation of Public Comment. Federal Register. Washington, D.C. Vol. 229, No. 74, pp. 62829-62830.
(December 1, 2009).
APPENDIX A REVISIONS TO SRP-LR
Table 3.3-1. Summary of Aging Management Programs for Auxiliary Systems Evaluated in Chapter VII of the GALL Report ID Type Component Aging Aging Management Further Evaluation Related Effect/Mechanism Programs Recommended Item 13 BWR/ Boral, boron steel and other Reduction of neutron- Monitoring of Neutron- No A-88 PWR materials (excluding Boraflex) absorbing capacity, Absorbing Materials other A-89 utilized as neutron absorbers in changes in dimension than Boraflex spent fuel storage racks neutron- that increase Keff, and absorbing sheets exposed to loss of material due to treated water or treated borated neutron-absorber water degradation and radiation
- A
- A Table 3.3-2. FSAR Supplement for Aging Management of Auxiliary Systems Implementation Program Description of Program Schedule*
Monitoring of Neutron- The program is implemented to assure that Program should Absorbing Materials other degradation of spent fuel pool neutron-absorbing be implemented than Boraflex material that could compromise the criticality before the period analysis will be detected in the period of extended of extended operation. The loss of material and the operation.
degradation of the neutron-absorbing material capacity are determined through coupon testing, direct in situ testing, or both. Such testing includes periodic verification of boron loss through areal density measurement of coupons or through direct in situ techniques, such as measurement of boron areal density, measurement of geometric changes in the material (blistering, pitting, and bulging),
and detection of gaps through blackness testing.
APPENDIX B REVISIONS TO GALL REPORT, VOLUME 1
Table 3. Summary of Aging Management Programs for the Auxiliary Systems Evaluated in Chapter VII of the GALL Report Further Related Aging Aging Management Unique ID Type Component Evaluation Generic Effect/Mechanism Programs Item Recommended Item 13 BWR/ Boral, boron steel and other Reduction of neutron- Monitoring of Neutron- No A-88 VII.A2-5 PWR materials (excluding absorbing capacity, Absorbing Materials other A-89 VII.A2-3 Boraflex) utilized as neutron changes in dimension than Boraflex absorbers in spent fuel that increase Keff, and storage racks neutron- loss of material due to absorbing sheets exposed to neutron-absorber treated water or treated degradation and borated water radiation
- B APPENDIX C REVISIONS TO GALL REPORT, VOLUME 2
VII AUXILIARY SYSTEMS A2 Spent Fuel Storage Structure Aging Effect/ Further Item Link and/or Material Environment Aging Management Program (AMP)
Mechanism Evaluation Component VII.A2-3 VII.A2.1-b Spent fuel Boral, Treated water Reduction of Chapter XI.M40, Monitoring of No storage racks boron steel neutron- Neutron-Absorbing Materials other (A-89) and other absorbing than Boraflex Neutron- materials capacity, absorbing (excluding changes in sheets - Boraflex) dimension that BWR utilized as increase Keff, neutron and loss of absorbers material due to neutron-absorber degradation and radiation
- C VII.A2-5 VII.A2.1-b Spent fuel Boral, Treated Reduction of Chapter XI.M40, Monitoring of No storage racks boron steel borated water neutron- Neutron-Absorbing Materials other (A-88) and other absorbing then Boraflex Neutron- materials capacity, absorbing (excluding changes in sheets - Boraflex) dimension that PWR utilized as increase Keff, neutron and loss of absorbers material due to neutron-absorber degradation and radiation
- C XI.M40 MONITORING OF NEUTRON-ABSORBING MATERIALS OTHER THAN BORAFLEX Program Description A monitoring program is implemented to assure that degradation of the neutron-absorbing material used in spent fuel pools that could compromise the criticality analysis will be detected.
The applicable aging management program (AMP) relies on periodic inspection, testing, monitoring, and analysis of the criticality design to assure that the required five percent subcriticality margin is maintained during the renewed license period.
Evaluation and Technical Basis
- 1. Scope of Program: The AMP manages the effects of aging on neutron-absorbing components/materials used in spent fuel racks.
- 2. Preventive Actions: This AMP is a condition monitoring program and therefore there are no preventative actions.
- 3. Parameters Monitored/Inspected: For these materials, gamma irradiation and/or long-term exposure to the wet pool environment may cause shrinkage resulting in loss of material, and changes in dimension (such as gap formation, formation of blisters, pits and bulges) which could result in loss of neutron absorbing capability of the material. The parameters monitored include the physical condition of the neutron-absorbing materials, such as in situ gap formation, geometric changes in the material (formation of blisters, pits, and bulges) as observed from coupons or in situ, and decreased boron areal density, etc. The parameters monitored should be directly related to determination of the loss of material or loss of neutron absorption capability of the material(s).
- 4. Detection of Aging Effects: The loss of material and the degradation of the neutron-absorbing material capacity are determined through coupon and/or direct in situ testing.
Such testing should include periodic verification of boron loss through areal density measurement of coupons or through direct in situ techniques which may include measurement of boron areal density, geometric changes in the material (blistering, pitting, and bulging), and detection of gaps through blackness testing. The frequency of the inspection and testing depends on the condition of the neutron-absorbing material and should be determined and justified with plant-specific operating experience by the licensee, not to exceed 10 years.
- 5. Monitoring and Trending: The measurements from periodic inspections and analysis are compared to baseline information or prior measurements and analysis for trend analysis.
The approach for relating the measurements to the performance of the spent fuel neutron absorber materials shall be specified by the applicant, considering differences in exposure conditions, vented/non-vented test samples and spent fuel racks, etc.
- 6. Acceptance Criteria: Although the goal is to ensure maintenance of the five percent subcriticality margin for the spent fuel pool, the specific acceptance criteria for the measurements and analyses shall be specified by the applicant.
- 7. Corrective Actions: Corrective actions are initiated if the results from measurements and analysis indicate that the five percent subcriticality margin cannot be maintained because of
- C the current or projected future degradation of the neutron-absorbing material. Corrective actions may consist of providing additional neutron-absorbing capacity with an alternate material, or applying other options, which are available to maintain the subcriticality margin.
As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B, acceptable to address the corrective actions.
- 8. Confirmation Process: Site quality assurance (QA) procedures, site review and approval processes, and administrative controls are implemented in accordance with the requirements of 10 CFR Part 50, Appendix B. As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B acceptable to address the confirmation process and administrative controls.
- 9. Administrative Controls: As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B, acceptable to address administrative controls.
- 10. Operating Experience: Applicants for license renewal should reference plant-specific operating experience and industry experience to provide reasonable assurance that the program will be able to detect degradation of the neutron absorbing material in the applicants spent fuel pool. Some of the industry operating experience that should be included is listed below:
- 1. Loss of material from the neutron absorbing material has been seen at many plants, including loss of aluminum which was detected by monitoring the aluminum concentration in the spent fuel pool. One instance of this was documented in the Vogtle LRA Water Chemistry Program B.3.28.
- 2. Blistering has also been noted at many plants. Examples include blistering at Seabrook and Beaver Valley.
- 3. The significant loss of neutron-absorbing capacity of the plate-type carborundum material has been reported at Palisades.
The applicant should describe how the monitoring program described above is capable of detecting the aforementioned degradation mechanisms.
References Letter from Christopher J. Schwarz, Entergy Nuclear Operations, Inc., Palisades Nuclear Plant, to the U.S. Nuclear Regulatory Commission, Commitments to Address Degraded Spent Fuel Pool Storage Rack Neutron Absorber, August 27, 2008, (ADAMS Accession No. ML082410132).
Letter from Kevin L. Ostrowski, FirstEnergy Nuclear Operating Company, to the U.S. Nuclear Regulatory Commission, Supplemental Information for the Review of the Beaver Valley Power Station, Units 1 and 2, License Renewal Application (TAC Nos. MD6593 and MD6594) and License Renewal Application Amendment No. 34, January 19, 2009, (ADAMS Accession No. ML090220216).
Letter from Mark E. Warner, FPL Energy Seabrook Station, to the U.S. Nuclear Regulatory Commission, Seabrook Station Boral Spent Fuel Pool Test Coupons Report Pursuant to 10 CFR Part 21.21, October 6, 2003 (ADAMS Accession No. ML032880525).
- C License Renewal Application Vogtle Electric Generating Plant Units 1 and 2, Southern Nuclear Operating Company, Inc., June 30, 2007 (ADAMS Accession No. ML071840360).
APPENDIX D MARK-UP SHOWING CHANGES TO THE LICENSE RENEWAL GUIDANCE DOCUMENTS
- D control program should be verified to ensure that cracking is not occurring. The GALL Report recommends that a plant-specific aging management program be evaluated to verify the absence of cracking due to SCC and cyclic loading to ensure that these aging effects are managed adequately. An acceptable verification program is to include temperature and radioactivity monitoring of the shell side water, and eddy current testing of tubes.
- 2. Cracking due to SCC and cyclic loading could occur in stainless steel PWR regenerative heat exchanger components exposed to treated borated water greater than 60°C (>140°F).
The existing aging management program relies on monitoring and control of primary water chemistry in PWRs to manage the aging effects of cracking due to SCC. However, control of water chemistry does not preclude cracking due to SCC and cyclic loading. Therefore, the effectiveness of the water chemistry control program should be verified to ensure that cracking is not occurring. The GALL Report recommends that a plant-specific aging management program be evaluated to verify the absence of cracking due to SCC and cyclic loading to ensure that these aging effects are managed adequately. Acceptance criteria are described in Branch Technical Position RLSB-1 (Appendix A.1 of this SRP-LR.)
- 3. Cracking due to SCC and cyclic loading could occur for the stainless steel pump casing for the PWR high-pressure pumps in the chemical and volume control system. The existing aging management program relies on monitoring and control of primary water chemistry in PWRs to manage the aging effects of cracking due to SCC. However, control of water chemistry does not preclude cracking due to SCC and cyclic loading. Therefore, the effectiveness of the water chemistry control program should be verified to ensure that cracking is not occurring. The GALL Report recommends that a plant-specific aging management program be evaluated to verify the absence of cracking due to SCC and cyclic loading to ensure that these aging effects are managed adequately. Acceptance criteria are described in Branch Technical Position RLSB-1 (Appendix A.1 of this SRP-LR.)
3.3.2.2.5 Hardening and Loss of Strength due to Elastomer Degradation
- 1. Hardening and loss of strength due to elastomer degradation could occur in elastomer seals and components of heating and ventilation systems exposed to air - indoor uncontrolled (internal/external. The GALL Report recommends further evaluation of a plant-specific aging management program to ensure that these aging effects are adequately managed.
Acceptance criteria are described in Branch Technical Position RLSB-1 (Appendix A.1 of this SRP-LR.)
- 2. Hardening loss of strength due to elastomer degradation could occur in elastomer linings of the filters, valves, and ion exchangers in spent fuel pool cooling and cleanup systems (BWR and PWR) exposed to treated water or to treated borated water. The GALL Report recommends that a plant-specific aging management program be evaluated to determine and assesses the qualified life of the linings in the environment to ensure that these aging effects are adequately managed. Acceptance criteria are described in Branch Technical Position RLSB-1 (Appendix A.1 of this SRP-LR.)
3.3.2.2.6 Reduction of Neutron-Absorbing Capacity and Loss of Material due to General Corrosion Reduction of neutron-absorbing capacity and loss of material due to general corrosion could occur in the neutron-absorbing sheets of BWR and PWR spent fuel storage racks exposed to treated water or to treated borated water. The GALL Report recommends further evaluation of a NUREG-1800, Rev. 1 3.3-4 September 2005
- D plant-specific aging management program to ensure that these aging effects are adequately managed. Acceptance criteria are described in Branch Technical Position RLSB-1 (Appendix A.1 of this SRP-LR).
3.3.2.2.7 Loss of Material due to General, Pitting, and Crevice Corrosion
- 1. Loss of material due to general, pitting, and crevice corrosion could occur in steel piping, piping components, and piping elements, including the tubing, valves, and tanks in the reactor coolant pump oil collection system, exposed to lubricating oil (as part of the fire protection system). The existing aging management program relies on the periodic sampling and analysis of lubricating oil to maintain contaminants within acceptable limits, thereby preserving an environment that is not conducive to corrosion. However, control of lube oil contaminants may not always have been adequate to preclude corrosion. Therefore, the effectiveness of lubricating oil control should be verified to ensure that corrosion is not occurring. The GALL Report recommends further evaluation of programs to manage corrosion to verify the effectiveness of the lubricating oil program. A one-time inspection of selected components at susceptible locations is an acceptable method to ensure that corrosion is not occurring and that the components intended function will be maintained during the period of extended operation.
In addition, corrosion may occur at locations in the reactor coolant pump oil collection tank where water from wash downs may accumulate. Therefore, the effectiveness of the program should be verified to ensure that corrosion is not occurring. The GALL Report recommends further evaluation of programs to manage loss of material due to general, pitting, and crevice corrosion, to include determining the thickness of the lower portion of the tank. A one-time inspection is an acceptable method to ensure that corrosion is not occurring and that the components intended function will be maintained during the period of extended operation.
- 2. Loss of material due to general, pitting, and crevice corrosion could occur in steel piping, piping components, and piping elements in the BWR reactor water cleanup and shutdown cooling systems exposed to treated water. The existing aging management program relies on monitoring and control of reactor water chemistry to manage the aging effects of loss of material from general, pitting and crevice corrosion. However, high concentrations of impurities at crevices and locations of stagnant flow conditions could cause general, pitting, or crevice corrosion. Therefore, the effectiveness of the chemistry control program should be verified to ensure that corrosion is not occurring. The GALL Report recommends further evaluation of programs to manage loss of material from general, pitting, and crevice corrosion to verify the effectiveness of the water chemistry program. A one-time inspection of select components at susceptible locations is an acceptable method to ensure that corrosion is not occurring and that the components intended function will be maintained during the period of extended operation.
- 3. Loss of material due to general (steel only) pitting and crevice corrosion could occur for steel and stainless steel diesel exhaust piping, piping components, and piping elements exposed to diesel exhaust. The GALL Report recommends further evaluation of a plant-specific aging management program to ensure that these aging effects are adequately managed.
Acceptance criteria are described in Branch Technical Position RLSB-1 (Appendix A.1 of this SRP-LR.)
September 2005 3.3-5 NUREG-1800, Rev. 1
- D monitoring of the shell side water, and eddy current testing of tubes. The reviewer reviews the applicants proposed program on a case-by-case basis to ensure that an adequate program will be in place for the management of these aging effects.
- 2. The GALL Report recommends further evaluation of programs to manage cracking due to SCC and cyclic loading in the stainless steel PWR regenerative heat exchanger components exposed to treated borated water greater than 60°C (>140°F). The water chemistry program relies on monitoring and control of water chemistry to manage the aging effects of cracking due to SCC and cyclic loading. The GALL Report recommends the effectiveness of the chemistry control program be verified to ensure that cracking is not occurring. The absence of cracking due to SCC and cyclic loading is to be verified. The reviewer reviews the applicants proposed program on a case-by-case basis to ensure that an adequate program will be in place for the management of these aging effects.
- 3. The GALL Report recommends further evaluation of programs to manage cracking due to cyclic loading for the stainless steel pump casing of high-pressure pumps in the PWR chemical and volume control system. The GALL Report recommends further evaluation to ensure that these aging effects are adequately managed. The reviewer reviews the applicants proposed program on a case-by-case basis to ensure that an adequate program will be in place for the management of these aging effects.
3.3.3.2.5 Hardening and Cracking or Loss of Strength due to Elastomer Degradation
- 1. The GALL Report recommends further evaluation of programs to manage the Hardening and loss of strength due to elastomer degradation could occur in elastomer seals and components of heating and ventilation systems exposed to air - indoor uncontrolled (internal/external. The reviewer reviews the applicants proposed program on a case-by-case basis to ensure that an adequate program will be in place for the management of these aging effects.
- 2. The GALL Report also recommends further evaluation of programs to manage the hardening and cracking due to elastomer degradation of valves in spent fuel pool cooling and cleanup system (BWR and PWR). The reviewer reviews the applicants proposed program on a case-by-case basis to ensure that an adequate program will be in place for the management of these aging effects.
3.3.3.2.6 Reduction of Neutron-Absorbing Capacity and Loss of Material due to General Corrosion The GALL Report recommends further evaluation of programs to manage reduction of neutron-absorbing capacity and loss of material due to general corrosion of the neutron-absorbing sheets in BWR and PWR spent fuel storage racks. The reviewer reviews the applicants proposed program on a case-by-case basis to ensure that an adequate program will be in place for the management of these aging effects.
3.3.3.2.7 Loss of Material due to General, Pitting, and Crevice Corrosion
- 1. The GALL Report recommends further evaluation of programs to manage the loss of material due to general, pitting, and crevice corrosion of steel piping, piping components, and piping elements exposed to lubricating oil, including the tanks, valve bodies, and tubing in the reactor coolant pump oil collection system (as part of the fire protection system). The NUREG-1800, Rev. 1 3.3-12 September 2005
Table 3.3-1. Summary of Aging Management Programs for Auxiliary Systems Evaluated in Chapter VII of the GALL Report ID Type Component Aging Aging Management Further Evaluation Related Effect/Mechanism Programs Recommended Item 11 BWR/ Elastomer seals and Hardening and loss of A plant specific aging Yes, plant specific A-17 PWR components exposed to air - strength due to elastomer management program is to (See subsection indoor uncontrolled degradation be evaluated. 3.3.2.2.5.1)
NUREG-1800, Rev. 1 (internal/external) 12 BWR/ Elastomer lining exposed to Hardening and loss of A plant specific aging Yes, plant specific A-15 PWR treated water or treated borated strength due to elastomer management program is to (See subsection A-16 water degradation be evaluated. 3.3.2.2.5.2) 13 BWR/ Boral, boron steel and other Reduction of neutron- A plant specific aging Yes, plant specific A-88 PWR materials (excluding Boraflex) absorbing capacity, management program is to (See subsection A-89 utilized as neutron absorbers in changes in dimension be evaluated. Monitoring of 3.3.2.2.6)No spent fuel storage racks neutron- that increase Keff, and Neutron-Absorbing Materials absorbing sheets exposed to loss of material due to other than Boraflex treated water or treated borated neutron-absorber water degradation and radiationgeneral 3.3-22 corrosion - D 14 BWR/ Steel piping, piping component, Loss of material due to Lubricating Oil Analysis and Yes, detection of AP-30 PWR and piping elements exposed to general, pitting, and One-Time Inspection aging effects is to be lubricating oil crevice corrosion evaluated (See subsection 3.3.2.2.7.1) 15 BWR/ Steel reactor coolant pump oil Loss of material due to Lubricating Oil Analysis and Yes, detection of A-83 PWR collection system piping, tubing, general, pitting, and One-Time Inspection aging effects is to be and valve bodies exposed to crevice corrosion evaluated (See lubricating oil subsection 3.3.2.2.7.1) 16 BWR/ Steel reactor coolant pump oil Loss of material due to Lubricating Oil Analysis and Yes, detection of A-82 PWR collection system tank exposed general, pitting, and One-Time Inspection to aging effects is to be to lubricating oil crevice corrosion evaluate the thickness of the evaluated (See lower portion of the tank subsection 3.3.2.2.7.1) 17 BWR Steel piping, piping components, Loss of material due to Water Chemistry and One- Yes, detection of A-35 and piping elements exposed to general, pitting, and Time Inspection aging effects is to be treated water crevice corrosion evaluated (See subsection September 2005 3.3.2.2.7.2)
- D Table 3.3-2. FSAR Supplement for Aging Management of Auxiliary Systems Implementation Program Description of Program Schedule*
Inspection of Internal The program visually inspects internal surfaces of Existing program Surfaces in Miscellaneous steel piping, piping elements, ducting, and Piping and Ducting components in an internal environment (indoor Components uncontrolled air, condensation, and steam) that (BWR/PWR) are not included in other aging management programs, for loss of material. Inspections are performed when the internal surfaces are accessible during the performance of periodic surveillance tests, during preventive maintenance activities or during scheduled outages. The program includes visual inspection to assure that existing environment conditions are not causing material degradation that could result in a loss of system intended functions.
Inspection of Overhead The program evaluates the effectiveness of the Existing program Heavy Load and Light maintenance monitoring program and the effects Load Handling System of past and future usage on the structural reliability of cranes and hoists. The number and magnitude of lifts made by the hoist or crane are also reviewed. Rails and girders are visually inspected on a routine basis for degradation.
Functional tests are also performed to assure their integrity. These cranes must also comply with the maintenance rule requirements provided in 10 CFR 50.65.
Lubricating Oil Analysis This program ensures the oil environment in the Existing program mechanical systems is maintained to the required quality. The program maintains oil systems free of contaminants (primarily water and particulates) thereby preserving an environment that is not conducive to loss of material, cracking, or reduction of heat transfer. Lubricating oil testing activities include sampling and analysis of lubricating oil for detrimental contaminants. The presence of water or particulates may also be indicative of inleakage and corrosion product buildup.
Monitoring of Neutron- The program is implemented to assure that Program should Absorbing Materials other degradation of spent fuel pool neutron-absorbing be implemented than Boraflex material that could compromise the criticality before the period analysis will be detected in the period of extended of extended operation. The loss of material and the operation.
degradation of the neutron-absorbing material capacity are determined through coupon testing, direct in situ testing, or both. Such testing includes periodic verification of boron loss through areal density measurement of coupons or through direct in situ techniques, such as measurement of boron areal density, measurement of geometric changes in the material (blistering, pitting, and bulging),
and detection of gaps through blackness testing.
September 2005 3.3-39 NUREG-1800, Rev. 1
- D One-Time Inspection This program verifies the effectiveness of other The inspection aging management program by determining if the should be aging effect is not occurring or the aging effect is completed progressing slowly so that the intended function before the period will be maintained during the period of extended of extended operation. operation.
September 2005 3.3-39 NUREG-1800, Rev. 1
Table 3. Summary of Aging Management Programs for the Auxiliary Systems Evaluated in Chapter VII of the GALL Report Further Related Aging Aging Management Unique ID Type Component Evaluation Generic Effect/Mechanism Programs Item Recommended Item 13 BWR/ Boral, boron steel and other Reduction of neutron- Plant specific Monitoring Yes, plant A-88 VII.A2-5 PWR materials (excluding absorbing capacity, of Neutron-Absorbing specificNo A-89 VII.A2-3 Boraflex) utilized as neutron changes in dimension Materials other than absorbers in spent fuel that increase Keff, Boraflex storage racks neutron- and loss of material NUREG-1801 Vol. 1, Rev. 1 absorbing sheets exposed to due to neutron-treated water or treated absorber degradation borated water and radiationgeneral corrosion 14 BWR/ Steel piping, piping Loss of material due to Lubricating Oil Analysis Yes, detection of AP-30 VII.C1-17 PWR component, and piping general, pitting, and and One-Time Inspection aging effects is to VII.C2-13 48 elements exposed to crevice corrosion be evaluated VII.E1-19
- D lubricating oil VII.E4-16 VII.F1-19 VII.F2-17 VII.F3-19 VII.F4-15 VII.G-22 VII.H2-20 15 BWR/ Steel reactor coolant pump Loss of material due to Lubricating Oil Analysis Yes, detection of A-83 VII.G-26 PWR oil collection system piping, general, pitting, and and One-Time Inspection aging effects is to tubing, and valve bodies crevice corrosion be evaluated exposed to lubricating oil 16 BWR/ Steel reactor coolant pump Loss of material due to Lubricating Oil Analysis Yes, detection of A-82 VII.G-27 PWR oil collection system tank general, pitting, and and One-Time Inspection aging effects is to exposed to lubricating oil crevice corrosion to evaluate the thickness be evaluated of the lower portion of the tank 17 BWR Steel piping, piping Loss of material due to Water Chemistry and Yes, detection of A-35 VII.E3-18 September 2005 components, and piping general, pitting, and One-Time Inspection aging effects is to VII.E4-17 elements exposed to treated crevice corrosion be evaluated water
VII AUXILIARY SYSTEMS A2 Spent Fuel Storage Structure Aging Effect/ Further Item Link and/or Material Environment Aging Management Program (AMP)
Mechanism Evaluation Component VII.A2-1 VII.A2. Piping, piping Stainless Treated Loss of material/ Chapter XI.M2, Water Chemistry, No NUREG-1801, Rev. 1 components, Steel; Steel borated water pitting and for PWR primary water (AP-79) and piping with crevice corrosion elements stainless steel cladding VII.A2-2 VII.A2.1-a Spent fuel Boraflex Treated water Reduction of Chapter XI.M22, Boraflex No storage racks neutron- Monitoring (A-87) absorbing Neutron- capacity/ boraflex absorbing degradation sheets -
- D VII A2-2 VII.A2-3 VII.A2.1-b Spent fuel Boral, Treated water Reduction of A plant-specific aging management Yes, plant-storage racks boron steel neutron- program is to be evaluated.Chapter specificNo (A-89) and other absorbing XI.M40, Monitoring of Neutron-Neutron- materials capacity, Absorbing Materials other than absorbing (excluding changes in Boraflex sheets - Boraflex) dimension that BWR utilized as increase Keff, neutron and loss of absorbers material due to neutron-absorber degradation and radiation/ general corrosion VII.A2-4 VII.A2.1-a Spent fuel Boraflex Treated Reduction of Chapter XI.M22, Boraflex No storage racks borated water neutron- Monitoring (A-86) absorbing Neutron- capacity/ boraflex absorbing degradation sheets -
September 2005 PWR
VII AUXILIARY SYSTEMS A2 Spent Fuel Storage Structure Aging Effect/ Further Item Link and/or Material Environment Aging Management Program (AMP)
Mechanism Evaluation Component September 2005 VII.A2-5 VII.A2.1-b Spent fuel Boral, Treated Reduction of A plant-specific aging management Yes, plant-storage racks boron steel borated water neutron- program is to be evaluated.Chapter specificNo (A-88) and other absorbing XI.M40, Monitoring of Neutron-Neutron- materials capacity, Absorbing Materials other then absorbing (excluding changes in Boraflex sheets - Boraflex) dimension that PWR utilized as increase Keff, neutron and loss of absorbers material due to neutron-absorber degradation and radiation/ general corrosion VII A2-3 - D VII.A2-6 VII.A2.1-c Spent fuel Stainless Treated water Cracking/ stress Chapter XI.M2, Water Chemistry, No storage racks steel >60ºC corrosion for BWR water (A-96) (>140ºF) cracking Storage racks - BWR VII.A2-7 VII.A2.1-c Spent fuel Stainless Treated Cracking/ stress Chapter XI.M2, Water Chemistry, No storage racks steel borated water corrosion for PWR primary water (A-97) >60ºC cracking Storage (>140ºF) racks - PWR NUREG-1801, Rev. 1
- D XI.M40 MONITORING OF NEUTRON-ABSORBING MATERIALS OTHER THAN BORAFLEX Program Description A monitoring program is implemented to assure that degradation of the neutron-absorbing material used in spent fuel pools that could compromise the criticality analysis will be detected.
The applicable aging management program (AMP) relies on periodic inspection, testing, monitoring, and analysis of the criticality design to assure that the required five percent subcriticality margin is maintained during the renewed license period.
Evaluation and Technical Basis
- 1. Scope of Program: The AMP manages the effects of aging on neutron-absorbing components/materials used in spent fuel racks.
- 2. Preventive Actions: This AMP is a condition monitoring program and therefore there are no preventative actions.
- 3. Parameters Monitored/Inspected: For these materials, gamma irradiation and/or long-term exposure to the wet pool environment may cause shrinkage resulting in loss of material, and changes in dimension (such as gap formation, formation of blisters, pits and bulges) which could result in loss of neutron absorbing capability of the material. The parameters monitored include the physical condition of the neutron-absorbing materials, such as in situ gap formation, geometric changes in the material (formation of blisters, pits, and bulges) as observed from coupons or in situ, and decreased boron areal density, etc. The parameters monitored should be directly related to determination of the loss of material or loss of neutron absorption capability of the material(s).
- 4. Detection of Aging Effects: The loss of material and the degradation of the neutron-absorbing material capacity are determined through coupon and/or direct in situ testing.
Such testing should include periodic verification of boron loss through areal density measurement of coupons or through direct in situ techniques which may include measurement of boron areal density, geometric changes in the material (blistering, pitting, and bulging), and detection of gaps through blackness testing. The frequency of the inspection and testing depends on the condition of the neutron-absorbing material and should be determined and justified with plant-specific operating experience by the licensee, not to exceed 10 years.
- 5. Monitoring and Trending: The measurements from periodic inspections and analysis are compared to baseline information or prior measurements and analysis for trend analysis.
The approach for relating the measurements to the performance of the spent fuel neutron absorber materials shall be specified by the applicant, considering differences in exposure conditions, vented/non-vented test samples and spent fuel racks, etc.
- 6. Acceptance Criteria: Although the goal is to ensure maintenance of the five percent subcriticality margin for the spent fuel pool, the specific acceptance criteria for the measurements and analyses shall be specified by the applicant.
- 7. Corrective Actions: Corrective actions are initiated if the results from measurements and analysis indicate that the five percent subcriticality margin cannot be maintained because of September 2005 XI M-125 NUREG-1801, Rev. 1
- D the current or projected future degradation of the neutron-absorbing material. Corrective actions may consist of providing additional neutron-absorbing capacity with an alternate material, or applying other options, which are available to maintain the subcriticality margin.
As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B, acceptable to address the corrective actions.
- 8. Confirmation Process: Site quality assurance (QA) procedures, site review and approval processes, and administrative controls are implemented in accordance with the requirements of 10 CFR Part 50, Appendix B. As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B acceptable to address the confirmation process and administrative controls.
- 9. Administrative Controls: As discussed in the appendix to this report, the staff finds the requirements of 10 CFR Part 50, Appendix B, acceptable to address administrative controls.
- 10. Operating Experience: Applicants for license renewal should reference plant-specific operating experience and industry experience to provide reasonable assurance that the program will be able to detect degradation of the neutron absorbing material in the applicants spent fuel pool. Some of the industry operating experience that should be included is listed below:
- 1. Loss of material from the neutron absorbing material has been seen at many plants, including loss of aluminum which was detected by monitoring the aluminum concentration in the spent fuel pool. One instance of this was documented in the Vogtle LRA Water Chemistry Program B.3.28.
- 2. Blistering has also been noted at many plants. Examples include blistering at Seabrook and Beaver Valley.
- 3. The significant loss of neutron-absorbing capacity of the plate-type carborundum material has been reported at Palisades.
The applicant should describe how the monitoring program described above is capable of detecting the aforementioned degradation mechanisms.
References Letter from Christopher J. Schwarz, Entergy Nuclear Operations, Inc., Palisades Nuclear Plant, to the U.S. Nuclear Regulatory Commission, Commitments to Address Degraded Spent Fuel Pool Storage Rack Neutron Absorber, August 27, 2008, (ADAMS Accession No. ML082410132).
Letter from Kevin L. Ostrowski, FirstEnergy Nuclear Operating Company, to the U.S. Nuclear Regulatory Commission, Supplemental Information for the Review of the Beaver Valley Power Station, Units 1 and 2, License Renewal Application (TAC Nos. MD6593 and MD6594) and License Renewal Application Amendment No. 34, January 19, 2009, (ADAMS Accession No. ML090220216).
Letter from Mark E. Warner, FPL Energy Seabrook Station, to the U.S. Nuclear Regulatory Commission, Seabrook Station Boral Spent Fuel Pool Test Coupons Report Pursuant to 10 CFR Part 21.21, October 6, 2003 (ADAMS Accession No. ML032880525).
NUREG-1801, Rev. 1 XI M-126 September 2005
- D License Renewal Application Vogtle Electric Generating Plant Units 1 and 2, Southern Nuclear Operating Company, Inc., June 30, 2007 (ADAMS Accession No. ML071840360).
September 2005 XI M-127 NUREG-1801, Rev. 1
APPENDIX E RESOLUTION OF PUBLIC COMMENTS ON DRAFT LR-ISG-2009-01
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.)
Southern Nuclear Operating Company (SNC) takes The third paragraph under the Boral exception to the statement in the Discussion section, heading in the Discussion section has under the Boral heading, that, Similarly, the spent been revised to include the word may to fuel pool water chemistry program at Vogtle clarify that there is the possibility that an documented an increase in the concentration of increased aluminum concentration indicates aluminum, which indicates loss of material from the loss of the Boral neutron-absorbing Southern Nuclear Operating Boral neutron absorbing material (Ref. 7). SNC does material.
Company, Inc. Letter dated 1 not believe that increasing aluminum concentration in December 17, 2009 the spent fuel pool water is conclusive evidence that Regarding the Vogtle Electric Generating (ML093570197) loss of material from the Boral neutron absorbing Plant operating experience, the increasing material is occurring. Therefore, it is inappropriate to aluminum concentration is an indication of use the Vogtle Electric Generating Plant operating degradation of the Boral cladding, which experience with aluminum concentration in the spent may indicate a larger problem.
fuel pool as indication of degradation of the Boral neutron absorbing material.
In item four, Detection of Aging Effects, under the In the aging management program Evaluation and Technical Basis heading of the description, the Detection of Aging Effects Exelon Generation attached aging management program, XI.XXXX item has been clarified to indicate that either Company, LLC Letter dated Monitoring of Neutron Absorbing Materials other than coupon testing or direct in situ testing, or 2
December 28, 2009 Boraflex, clarify the intent of the requirement to both, may be used to detect the aging (ML100060388) specify whether in situ testing methods can be used in effects of concern.
lieu of coupon measurements, or if both are required in lieu of the alternate methods listed.
In item ten, Operating Experience, under the In the aging management program Evaluation and Technical Basis heading of the description, the Operating Experience item Exelon Generation attached aging management program, XI.XXXX has been clarified to reflect the Palisades Company, LLC Letter dated Monitoring of Neutron Absorbing Materials other than Nuclear Plant operating experience 3
December 28, 2009 Boraflex, the listed operating experience includes the concerning the plate-type carborundum (ML100060388) loss of neutron-absorbing capacity of the material at material.
the Palisades plant. Please clarify that material for this example was carborundum and not Boral.
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.)
Clarify in the LR-ISG that if the neutron absorber is Some clarifications have been made as not credited in the licensees' criticality analysis, then a discussed in the response to Comment surveillance program for that neutron absorber is not No. 11. No other changes to the LR-ISG Nuclear Energy Institute required. are necessary because neutron absorbers Letter dated December 31, 4 not credited in the applicant's criticality 2009 analysis are not within the scope of license (ML100060387) renewal, as defined in 10 CFR 54.4.
Therefore, an aging management review of such components is not required.
The LR-ISG does not provide a viable option for those No changes to the LR-ISG have been licensees that do not have a coupon testing program. incorporated. The NRCs staffs intent is not Nuclear Energy Institute The LR-ISG would require the performance of to recommend "continuous" testing, but Letter dated December 31, 5 continuous neutron absorber areal density rather periodic coupon or in situ testing.
2009 measurements (blackness testing). Provide a viable (ML100060387) alternative to continuous blackness testing for the effected licensees.
Consider the addition of allowing licensees to No changes to the LR-ISG have been demonstrate that the combination of the neutron incorporated. The LR-ISG provides absorber manufacturing process, spent fuel pool guidance as to one acceptable approach for environment and previous/existing testing provides managing the effects of aging during the Nuclear Energy Institute reasonable assurance of the continued efficacy of the period of extended operation for certain Letter dated December 31, 6 neutron absorber capability in lieu of a testing neutron-absorbing spent fuel pool 2009 program. components; however, this guidance does (ML100060387) not preclude a license renewal applicant from proposing and justifying other approaches for managing the effects of aging.
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.)
The Discussion section, under the Carborundum Comment incorporated.
heading states: The swelling of the racks, which prevents fuel assemblies from being inserted or removed, indicates a potential problem with neutron-absorbing capacity. However, swelling of racks does Nuclear Energy Institute not necessarily provide an indication of a loss of Letter dated December 31, 7 neutron absorption capacity. Root cause evaluations 2009 have not provided a clear link between swelling and (ML100060387) the loss of neutron absorption. Therefore, change this sentence to: The swelling of the racks, which prevents fuel assemblies from being inserted or removed, may indicate a potential problem with neutron-absorbing capacity.
In the Discussion section, under the Carborundum A clarification has been made in the subject heading, clarify that another form of carborundum paragraph to indicate that the discussion Nuclear Energy Institute does exist and it has not experienced similar concerns only plate-type carborundum.
Letter dated December 31, 8 degradation mechanisms to that of the plate type 2009 carborundum found at Palisades. Add the sentence, (ML100060387)
This only applies to the plate type Carborundum, to the end of the second paragraph under this heading.
On page four, under the heading, GALL Report, No changes to the LR-ISG have been Vol. 2, revise the Table VII.A2 to allow credit for incorporated. An appropriate technical Nuclear Energy Institute water chemistry in managing the aging effect of loss basis to support incorporation of this Letter dated December 31, of material by adding a line item to reference the comment has not been provided. The staff 9
2009 aging management program in GALL Report, has found that a surveillance program, as (ML100060387) Volume 2,Section XI.M2, Water Chemistry. described in the aging management program, is necessary for managing aging in this area.
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.)
On page five, under the heading, SRP-LR, change The LR-ISG reflects changes to the aging the last sentence to: Reduction of neutron-absorbing effect/mechanism description in the revised capacity, changes in dimension that increase Keff or SRP-LR Table 3.3-1, item 13, GALL Report, negatively affect criticality and loss of material due to Volume 1, Table 3, item 13, and GALL the effects of the SFP environment. This change Report, Volume 2, Table VII.A2, items would acknowledge that a decrease in Keff could VII.A2-3 and VII.A2-5, to include changes occur and is not prohibited. in dimension that increase Keff. The intent Nuclear Energy Institute of the LR-ISG is to provide guidance for Letter dated December 31, managing the detrimental effects of aging, 10 2009 and changes in dimension that decrease (ML100060387) Keff are not detrimental aging effects.
The proposed language in the comment includes the text: or negatively affect criticality. For conciseness, this text was not incorporated because negative effects on criticality are the same as increases in Keff.
For clarification purposes, change the revised The LR-ISG reflects changes to the component item descriptions under the headings, component description in the revised GALL Report, Vol. 1 and SRP-LR, to: Boral, boron SRP-LR Table 3.3-1, item 13, and GALL Nuclear Energy Institute steel and other materials (excluding Boraflex) utilized Report, Volume 1, Table 3, item 13, to Letter dated December 31, 11 as neutron absorbers in spent fuel storage racks, clarify that the materials are utilized as 2009 exposed to treated water or treated borated water and neutron absorbers. This change is also (ML100060387) radiation effect. reflected in the material descriptions in the revised GALL Report, Volume 2, Table VII.A2, items VII.A2-3 and VII.A2-5.
For clarity, in item one, Scope of Program, under the Comment incorporated.
Nuclear Energy Institute Evaluation and Technical Basis heading of the Letter dated December 31, attached aging management program, XI.XXXX 12 2009 Monitoring of Neutron Absorbing Materials other than (ML100060387) Boraflex, move the second sentence to item three, Parameters Monitored/Inspected.
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.)
In item three, Parameters Monitored/Inspected, No changes to the LR-ISG have been under the Evaluation and Technical Basis heading of incorporated. The LR-ISG provides the attached aging management program, XI.XXXX guidance as to one acceptable approach for Monitoring of Neutron Absorbing Materials other than managing the effects of aging during the Nuclear Energy Institute Boraflex, add the following sentence: Where it can period of extended operation for certain Letter dated December 31, 13 be shown that for a specific material and environment neutron-absorbing spent fuel pool 2009 test results are not site-specific, the use of shared components; however, this guidance does (ML100060387) industry coupon testing results is acceptable. not preclude a license renewal applicant from proposing and justifying other approaches for managing the effects of aging.
In item four, Detection of Aging Effects, under the Comment incorporated.
Evaluation and Technical Basis heading of the attached aging management program, XI.XXXX Monitoring of Neutron Absorbing Materials other than Boraflex, change the first sentence to: "The loss of material and the degradation of the neutron-absorbing material capacity are determined through coupon or in Nuclear Energy Institute situ testing. Such testing includes measurement of Letter dated December 31, 14 boron areal density, geometric changes in the material 2009 (blistering, pitting, and bulging), detection of gaps (ML100060387) through blackness testing, and periodic verification of boron loss through in-situ areal density measurements or coupon testing. This change clarifies that in situ or coupon testing is acceptable, it also eliminate the specific reference to BADGER testing so that it does not appear NRC is advocating a specific manufacturer's type of testing.
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.)
Regarding item four, Detection of Aging Effects, The 10-year maximum period between under the Evaluation and Technical Basis heading of inspections ensures that at least one set of the attached aging management program, XI.XXXX inspection and testing results will be Monitoring of Neutron Absorbing Materials other than acquired during the period of extended Boraflex, provide the basis for a testing frequency of operation. This period is consistent with a maximum of 10 years. Use of operating experience current industry inservice inspection should be permitted to allow licensees to determine requirements for component inspections Nuclear Energy Institute the appropriate inspection frequency requirements. under 10 CFR 50.55a and the Section XI of Letter dated December 31, Therefore, delete the words, with a maximum of the American Society of Mechanical 15 2009 10 years from the last sentence of this item. Engineers Code.
In the aging management program description, the Detection of Aging Effects item has been clarified to state that applicants should determine and justify the inspection and testing frequency based on operating experience; however, this frequency is not to exceed 10 years.
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.)
Concerning the second sentence of item seven, Comment incorporated.
Corrective Actions, under the Evaluation and Technical Basis heading of the attached aging management program, XI.XXXX Monitoring of Neutron Absorbing Materials other than Boraflex, (1) change Corrective actions consist of to:
Corrective actions may consist of This change is to clarify that the licensees' corrective action process will determine the appropriate actions. Also, Nuclear Energy Institute Letter dated December 31, (2) those licensees with 10 CFR 50.68(b)(4) as their 16 2009 licensing basis comply with the regulatory requirement (ML100060387) that the spent fuel pool remain subcritical without soluble boron. Therefore, the five percent subcritical margin referred to is only applicable for normal conditions for those licensees.
Given these two comments, change the second sentence of item seven to: "Corrective actions may consist of providing additional neutron-absorbing capacity with an alternate material, or applying other options, which are available to maintain the appropriate subcriticality margin.
The term Carborundum is used rather than No changes to the LR-ISG have been something more generic. Carborundum is the incorporated. Carborundum is referenced manufacturer of a neutron-absorber which consists of in the LR-ISG either as an example of a boron-carbide in a phenol formaldehyde resin. Other neutron-absorbing material or in the Nuclear Energy Institute manufacturers (e.g., ESK) manufacture boron-carbide description of plant-specific operating 17 Email dated January 6, 2010 in a phenolic resin, which is a similar material. The experience for carborundum.
(ML100280648) term carborundum is used throughout the document in a generic sense and it should only be used for those specific stations that have carborundum (e.g.,
Palisades).
- E Comment Comment Source Comment on Draft LR-ISG-2009-01 NRC Staff Response No. (ADAMS Accession No.)
The LR-ISG uses the term, Region 1 Fuel Storage The definition or region 1 racks has been Racks. This is specific rack defined by a specific clarified as high reactivity, unburned reload Nuclear Energy Institute station. This term should be better defined, for fuel, as defined in Electric Power Research 18 Email dated January 6, 2010 example, use fuel storage racks that receive freshly Institutes Handbook of Neutron Absorber (ML100280648) discharged fuel, or something similar. Materials for Spent Fuel Transportation and Storage Applications, dated 2006.