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 neutronabsorbing materials is described in the following sections. 
- 2 - 

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 licensee’s 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 
- 3 - 

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 BORALTM 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 BORALTM, 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 applicant’s 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 

material’s 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 neutronabsorbing 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 
- 4 - 

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 staff’s 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 applicant’s 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 staff’s 

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 plantspecific, aging management recommendations. 
- 5 - 

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 
- 6 - 

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 neutronabsorbing 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. 
- 7 - 

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 NRC’s 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 
- A-2 - 

Table 3.3-1. Summary of Aging Management Programs for Auxiliary Systems Evaluated in Chapter VII of the GALL Report 

Related ItemA-88 A-89 

Further Evaluation RecommendedNo 

Aging Management Programs Monitoring of NeutronAbsorbing Materials other than Boraflex 

Aging Effect/Mechanism Reduction of neutronabsorbing capacity, changes in dimension that increase Keff, and loss of material due to neutron-absorber degradation and radiation 

ComponentBoral, boron steel and other materials (excluding Boraflex) utilized as neutron absorbers in spent fuel storage racks neutronabsorbing sheets exposed to treated water or treated borated water 

Type

BWR/ 

PWR 

ID

13 
- A-3 - 

Table 3.3-2. FSAR Supplement for Aging Management of Auxiliary Systems 

Program Description of Program Implementation 

Schedule* 

Monitoring of NeutronAbsorbing Materials other 

than Boraflex 

The program is implemented to assure that 

degradation of spent fuel pool neutron-absorbing 

material that could compromise the criticality 

analysis will be detected in the period of extended 

operation. The loss of material and the 

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. 

Program should 

be implemented 

before the period 

of extended 

operation. 
APPENDIX B 

REVISIONS TO GALL REPORT, VOLUME 1 
- B-2 - 

Table 3. Summary of Aging Management Programs for the Auxiliary Systems Evaluated in Chapter VII of the GALL Report 

Unique Item VII.A2-5 VII.A2-3 

Related Generic Item A-88 A-89 

Further Evaluation Recommended No 

Aging Management Programs  Monitoring of NeutronAbsorbing Materials other than Boraflex 

Aging Effect/Mechanism Reduction of neutronabsorbing capacity, changes in dimension that increase Keff, and loss of material due to neutron-absorber degradation and radiation 

ComponentBoral, boron steel and other materials (excluding Boraflex) utilized as neutron absorbers in spent fuel storage racks neutronabsorbing sheets exposed to treated water or treated borated water 

Type

BWR/ 

PWR 

ID

13 
APPENDIX C 

REVISIONS TO GALL REPORT, VOLUME 2 
- C-2 - 

AUXILIARY SYSTEMS Spent Fuel Storage 

Further Evaluation No No 

Aging Management Program (AMP) Chapter XI.M40, “Monitoring of Neutron-Absorbing Materials other than Boraflex” Chapter XI.M40, “Monitoring of Neutron-Absorbing Materials other then Boraflex” 

Aging Effect/ Mechanism Reduction of neutronabsorbing capacity, changes in dimension that increase Keff, and loss of material due to neutron-absorber degradation and radiation Reduction of neutronabsorbing capacity, changes in dimension that increase Keff, and loss of material due to neutron-absorber degradation and radiation 

Environment Treated water Treated borated water 

Material Boral, boron steel and other materials (excluding Boraflex) utilized as neutron absorbers Boral, boron steel and other materials (excluding Boraflex) utilized as neutron absorbers 

Structure and/or Component Spent fuel storage racks Neutronabsorbing sheets - BWR Spent fuel storage racks Neutronabsorbing sheets - PWR 

Link VII.A2.1-b VII.A2.1-b 

VII A2 Item VII.A2-3 (A-89) VII.A2-5 (A-88) 
- C-3 - 

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 neutronabsorbing 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-4 - 

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 

applicant’s 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-5 - 

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-2 - 

NUREG-1800, Rev. 1 3.3-4 September 2005 

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
- D-3 - 

September 2005 3.3-5 NUREG-1800, Rev. 1 

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 component’s 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 component’s 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 component’s 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.)
- D-4 - 

NUREG-1800, Rev. 1 3.3-12 September 2005 

monitoring of the shell side water, and eddy current testing of tubes. The reviewer reviews 

the applicant’s 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 applicant’s 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 

applicant’s 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 applicant’s proposed program on a case-bycase 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 applicant’s 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 neutronabsorbing 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 applicant’s

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 
- D-5 - 

NUREG-1800, Rev. 1 3.3-22 September 2005 Table 3.3-1. Summary of Aging Management Programs for Auxiliary Systems Evaluated in Chapter VII of the GALL Report Related Item A-17 A-15 A-16 A-88 A-89 AP-30 A-83 A-82 A-35 Further Evaluation Recommended Yes, plant specific (See subsection 3.3.2.2.5.1) Yes, plant specific (See subsection 3.3.2.2.5.2) Yes, plant specific (See subsection 3.3.2.2.6)No Yes, detection of aging effects is to be evaluated (See subsection 3.3.2.2.7.1) Yes, detection of aging effects is to be evaluated (See subsection 3.3.2.2.7.1) Yes, detection of aging effects is to be evaluated (See subsection 3.3.2.2.7.1) Yes, detection of aging effects is to be evaluated (See subsection 3.3.2.2.7.2) Aging Management Programs A plant specific aging management program is to be evaluated. A plant specific aging management program is to be evaluated. A plant specific aging management program is to be evaluated. Monitoring of Neutron-Absorbing Materials other than Boraflex Lubricating Oil Analysis and One-Time Inspection Lubricating Oil Analysis and One-Time Inspection Lubricating Oil Analysis and One-Time Inspection to evaluate the thickness of the lower portion of the tank Water Chemistry and One- Time Inspection Aging Effect/Mechanism Hardening and loss of strength due to elastomer degradation Hardening and loss of strength due to elastomer degradation Reduction of neutron- absorbing capacity, changes in dimension that increase Keff, and loss of material due to neutron-absorber degradation and radiationgeneral corrosion Loss of material due to general, pitting, and crevice corrosion Loss of material due to general, pitting, and crevice corrosion Loss of material due to general, pitting, and crevice corrosion Loss of material due to general, pitting, and crevice corrosion Component Elastomer seals and components exposed to air – indoor uncontrolled (internal/external) Elastomer lining exposed to treated water or treated borated water Boral, boron steel and other materials (excluding Boraflex) utilized as neutron absorbers in spent fuel storage racks neutron- absorbing sheets exposed to treated water or treated borated water Steel piping, piping component, and piping elements exposed to lubricating oil Steel reactor coolant pump oil collection system piping, tubing, and valve bodies exposed to lubricating oil Steel reactor coolant pump oil collection system tank exposed to lubricating oil Steel piping, piping components, and piping elements exposed to treated water Type BWR/ PWR BWR/ PWR BWR/ PWR BWR/ PWR BWR/ PWR BWR/ PWR BWR ID11 12 13 14 15 16 17 
- D-6 - 

September 2005 3.3-39 NUREG-1800, Rev. 1 

Table 3.3-2. FSAR Supplement for Aging Management of Auxiliary Systems 

Program Description of Program Implementation 

Schedule* 

Inspection of Internal 

Surfaces in Miscellaneous 

Piping and Ducting 

Components 

(BWR/PWR) 

The program visually inspects internal surfaces of 

steel piping, piping elements, ducting, and 

components in an internal environment (indoor 

uncontrolled air, condensation, and steam) that 

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. 

Existing program 

Inspection of Overhead 

Heavy Load and Light 

Load Handling System 

The program evaluates the effectiveness of the 

maintenance monitoring program and the effects 

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. 

Existing program 

Lubricating Oil Analysis This program ensures the oil environment in the 

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. 

Existing program 

Monitoring of NeutronAbsorbing Materials other 

than Boraflex

The program is implemented to assure that 

degradation of spent fuel pool neutron-absorbing 

material that could compromise the criticality 

analysis will be detected in the period of extended 

operation. The loss of material and the 

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.

Program should 

be implemented 

before the period 

of extended 

operation.
- D-7 - 

September 2005 3.3-39 NUREG-1800, Rev. 1 

One-Time Inspection This program verifies the effectiveness of other 

aging management program by determining if the 

aging effect is not occurring or the aging effect is 

progressing slowly so that the intended function 

will be maintained during the period of extended 

operation. 

The inspection 

should be 

completed 

before the period 

of extended 

operation. 
- D-8 - 

NUREG-1801 Vol. 1, Rev. 1 48 September 2005 Table 3. Summary of Aging Management Programs for the Auxiliary Systems Evaluated in Chapter VII of the GALL Report Unique Item VII.A2-5 VII.A2-3 VII.C1-17 VII.C2-13 VII.E1-19 VII.E4-16 VII.F1-19 VII.F2-17 VII.F3-19 VII.F4-15 VII.G-22 VII.H2-20 VII.G-26 VII.G-27 VII.E3-18 VII.E4-17 Related Generic Item A-88 A-89 AP-30 A-83 A-82 A-35 Further Evaluation Recommended Yes, plant specificNo Yes, detection of aging effects is to be evaluated Yes, detection of aging effects is to be evaluated Yes, detection of aging effects is to be evaluated Yes, detection of aging effects is to 

be evaluated 

Aging Management Programs Plant specific Monitoring of Neutron-Absorbing Materials other than BoraflexLubricating Oil Analysis and One-Time Inspection Lubricating Oil Analysis and One-Time Inspection Lubricating Oil Analysis and One-Time Inspection to evaluate the thickness of the lower portion of the tank Water Chemistry and One-Time Inspection 

Aging Effect/Mechanism Reduction of neutronabsorbing capacity, changes in dimensionthat increase Keff, and loss of material due to neutronabsorber degradation and radiationgeneralcorrosionLoss of material due to general, pitting, and crevice corrosion Loss of material due to general, pitting, and crevice corrosion Loss of material due to general, pitting, and crevice corrosion Loss of material due to general, pitting, and crevice corrosion 

ComponentBoral, boron steel and other materials (excludingBoraflex) utilized as neutron absorbers in spent fuel storage racks neutronabsorbing sheets exposed to treated water or treated borated water Steel piping, piping component, and piping elements exposed to lubricating oil Steel reactor coolant pump oil collection system piping, tubing, and valve bodies exposed to lubricating oil Steel reactor coolant pump oil collection system tank exposed to lubricating oil Steel piping, piping components, and piping elements exposed to treated water 

Type

BWR/ 

PWR 

BWR/ 

PWR 

BWR/ 

PWR 

BWR/ 

PWR BWR 

ID

13 14 15 16 17 
- D-9 - 

NUREG-1801, Rev. 1 VII A2-2 September 2005 AUXILIARY SYSTEMS Spent Fuel Storage Further Evaluation No No Yes, plant- specificNo No Aging Management Program (AMP) Chapter XI.M2, “Water Chemistry,” for PWR primary water Chapter XI.M22, “Boraflex Monitoring” A plant-specific aging management program is to be evaluated.Chapter XI.M40, “Monitoring of Neutron- Absorbing Materials other than Boraflex” Chapter XI.M22, ‘”Boraflex Monitoring” Aging Effect/ Mechanism Loss of material/ pitting and crevice corrosion Reduction of neutron- absorbing capacity/ boraflex degradation Reduction of neutron- absorbing capacity, changes in dimension that increase Keff, and loss of material due to neutron-absorber degradation and radiation/ general corrosion Reduction of neutron- absorbing capacity/ boraflex degradation Environment Treated borated water Treated water Treated water Treated borated water Material Stainless Steel; Steel with stainless steel cladding Boraflex Boral, boron steel and other materials (excluding Boraflex) utilized as neutron absorbers Boraflex Structure and/or Component Piping, piping components, and piping elements Spent fuel storage racks Neutron- absorbing sheets - BWR Spent fuel storage racks Neutron- absorbing sheets - BWR Spent fuel storage racks Neutron- absorbing sheets - PWR Link VII.A2. VII.A2.1-a VII.A2.1-b VII.A2.1-a VII A2 Item VII.A2-1 (AP-79) VII.A2-2 (A-87) VII.A2-3 (A-89) VII.A2-4 (A-86) 
- D-10 - 

September 2005 VII A2-3 NUREG-1801, Rev. 1 AUXILIARY SYSTEMS Spent Fuel Storage Further Evaluation Yes, plant- specificNo No No Aging Management Program (AMP) A plant-specific aging management program is to be evaluated.Chapter XI.M40, “Monitoring of Neutron- Absorbing Materials other then Boraflex” Chapter XI.M2, “Water Chemistry,” for BWR water Chapter XI.M2, “Water Chemistry,” for PWR primary water Aging Effect/ Mechanism Reduction of neutron- absorbing capacity, changes in dimension that increase Keff, and loss of material due to neutron-absorber degradation and radiation/ general corrosion Cracking/ stress corrosion cracking Cracking/ stress corrosion cracking Environment Treated borated water Treated water >60oC (>140oF) Treated borated water >60oC (>140oF) Material Boral, boron steel and other materials (excluding Boraflex) utilized as neutron absorbers Stainless steel Stainless steel Structure and/or Component Spent fuel storage racks Neutron- absorbing sheets - PWR Spent fuel storage racks Storage racks - BWR Spent fuel storage racks Storage racks - PWR Link VII.A2.1-b VII.A2.1-c VII.A2.1-c VII A2 Item VII.A2-5 (A-88) VII.A2-6 (A-96) VII.A2-7 (A-97) 
- D-11 - 

September 2005 XI M-125 NUREG-1801, Rev. 1

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 neutronabsorbing 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 
- D-12 - 

NUREG-1801, Rev. 1 XI M-126 September 2005

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 

applicant’s 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).
- D-13 - 

September 2005 XI M-127 NUREG-1801, Rev. 1

License Renewal Application Vogtle Electric Generating Plant Units 1 and 2, Southern Nuclear 

Operating Company, Inc., June 30, 2007 (ADAMS Accession No. ML071840360).
APPENDIX E 

RESOLUTION OF PUBLIC COMMENTS ON DRAFT LR-ISG-2009-01
- E-2 - 

Comment 

No. 

Comment Source 

(ADAMS Accession No.) Comment on Draft LR-ISG-2009-01 NRC Sta

1 

Southern Nuclear Operating 

Company, Inc. Letter dated 

December 17, 2009 

(ML093570197) 

Southern Nuclear Operating Company (SNC) takes exception to the statement in the “Discussion” section, under the “Boral” heading, that, “Similarly, the spent fuel pool water chemistry program at Vogtle documented an increase in the concentration of aluminum, which indicates loss of material from the Boral neutron absorbing material (Ref. 7).” SNC does not believe that increasing aluminum concentration in the spent fuel pool water is conclusive evidence that loss of material from the Boral neutron absorbing material is occurring. Therefore, it is inappropriate to use the Vogtle Electric Generating Plant operating experience with aluminum concentration in the spent fuel pool as indication of degradation of the Boral neutron absorbing material. 

The third paragraph heading in the “Discbeen revised to inclclarify that there is tincreased aluminum loss of the Boral nematerial. Regarding the VogtPlant operating expaluminum concentradegradation of the Bmay indicate a large

2 

Exelon Generation 

Company, LLC Letter dated 

December 28, 2009 

(ML100060388) 

In item four, “Detection of Aging Effects,” under the “Evaluation and Technical Basis” heading of the attached aging management program, “XI.XXXX Monitoring of Neutron Absorbing Materials other than Boraflex,” clarify the intent of the requirement to specify whether in situ testing methods can be used in lieu of coupon measurements, or if both are required in lieu of the alternate methods listed. 

In the aging managedescription, the “Deitem has been clarifcoupon testing or diboth, may be used teffects of concern. 

3 

Exelon Generation 

Company, LLC Letter dated 

December 28, 2009 

(ML100060388) 

In item ten, “Operating Experience,” under the “Evaluation and Technical Basis” heading of the attached aging management program, “XI.XXXX Monitoring of Neutron Absorbing Materials other than Boraflex,” the listed operating experience includes the loss of neutron-absorbing capacity of the material at the Palisades plant. Please clarify that material for this example was carborundum and not Boral. 

In the aging managedescription, the “Ophas been clarified to Nuclear Plant operaconcerning the platematerial. 
- E-3 - 

Comment 

No. 

Comment Source 

(ADAMS Accession No.) Comment on Draft LR-ISG-2009-01 NRC Sta

4 

Nuclear Energy Institute 

Letter dated December 31, 

2009 

(ML100060387) 

Clarify in the LR-ISG that if the neutron absorber is not credited in the licensees' criticality analysis, then a surveillance program for that neutron absorber is not required. 

Some clarifications discussed in the resNo. 11. No other chare necessary becanot credited in the aanalysis are not withrenewal, as defined Therefore, an aging such components is 

5 

Nuclear Energy Institute 

Letter dated December 31, 

2009 

(ML100060387) 

The LR-ISG does not provide a viable option for those licensees that do not have a coupon testing program. The LR-ISG would require the performance of continuous neutron absorber areal density measurements (blackness testing). Provide a viable alternative to continuous blackness testing for the effected licensees. 

No changes to the Lincorporated. The Nto recommend "conrather periodic coup

6 

Nuclear Energy Institute 

Letter dated December 31, 

2009 

(ML100060387) 

Consider the addition of allowing licensees to demonstrate that the combination of the neutron absorber manufacturing process, spent fuel pool environment and previous/existing testing provides reasonable assurance of the continued efficacy of the neutron absorber capability in lieu of a testing program. 

No changes to the Lincorporated. The Lguidance as to one managing the effectperiod of extended oneutron-absorbing scomponents; howevnot preclude a licenfrom proposing and approaches for managing. 
- E-4 - 

Comment 

No. 

Comment Source 

(ADAMS Accession No.) Comment on Draft LR-ISG-2009-01 NRC Sta

7 

Nuclear Energy Institute 

Letter dated December 31, 

2009 

(ML100060387) 

The “Discussion” section, under the “Carborundum” heading states: “The swelling of the racks, which prevents fuel assemblies from being inserted or removed, indicates a potential problem with neutronabsorbing capacity.” However, swelling of racks does not necessarily provide an indication of a loss of neutron absorption capacity. Root cause evaluations have not provided a clear link between swelling and 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.” 

Comment incorpora

8 

Nuclear Energy Institute 

Letter dated December 31, 

2009 

(ML100060387) 

In the “Discussion” section, under the “Carborundum” heading, clarify that another form of carborundum does exist and it has not experienced similar degradation mechanisms to that of the plate type carborundum found at Palisades. Add the sentence, “This only applies to the plate type Carborundum,” to the end of the second paragraph under this heading. 

A clarification has bparagraph to indicatconcerns only “plate

9 

Nuclear Energy Institute 

Letter dated December 31, 

2009 

(ML100060387) 

On page four, under the heading, “GALL Report, Vol. 2,” revise the Table VII.A2 to allow credit for water chemistry in managing the aging effect of loss of material by adding a line item to reference the aging management program in GALL Report, Volume 2, Section XI.M2, “Water Chemistry.” 

No changes to the Lincorporated. An apbasis to support inccomment has not behas found that a surdescribed in the agiprogram, is necessain this area. 
- E-5 - 

Comment 

No. 

Comment Source 

(ADAMS Accession No.) Comment on Draft LR-ISG-2009-01 NRC Sta

10 

Nuclear Energy Institute 

Letter dated December 31, 

2009 

(ML100060387) 

On page five, under the heading, “SRP-LR,” change the last sentence to: “Reduction of neutron-absorbing capacity, changes in dimension that increase Keff or negatively affect criticality and loss of material due to the effects of the SFP environment.” This change would acknowledge that a decrease in Keff could occur and is not prohibited. 

The LR-ISG reflects effect/mechanism” dSRP-LR Table 3.3-1Volume 1, Table 3, Report, Volume 2, TVII.A2-3 and VII.A2-in dimension that inof the LR-ISG is to pmanaging the detrimand changes in dimKeff are not detrimeThe proposed languincludes the text: “ocriticality.” For concnot incorporated beon criticality are the Keff. 

11 

Nuclear Energy Institute 

Letter dated December 31, 

2009 

(ML100060387) 

For clarification purposes, change the revised component item descriptions under the headings, “GALL Report, Vol. 1” and “SRP-LR,” to: “Boral, boron steel and other materials (excluding Boraflex) utilized as neutron absorbers in spent fuel storage racks, exposed to treated water or treated borated water and radiation effect.” 

The LR-ISG reflects “component” descripSRP-LR Table 3.3-1Report, Volume 1, Tclarify that the mateneutron absorbers.” reflected in the “matrevised GALL RepoVII.A2, items VII.A2

12 

Nuclear Energy Institute 

Letter dated December 31, 

2009 

(ML100060387) 

For clarity, in item one, “Scope of Program,” under the “Evaluation and Technical Basis” heading of the attached aging management program, “XI.XXXX Monitoring of Neutron Absorbing Materials other than Boraflex,” move the second sentence to item three, “Parameters Monitored/Inspected.” 

Comment incorpora
- E-6 - 

Comment 

No. 

Comment Source 

(ADAMS Accession No.) Comment on Draft LR-ISG-2009-01 NRC Sta

13 

Nuclear Energy Institute 

Letter dated December 31, 

2009 

(ML100060387) 

In item three, “Parameters Monitored/Inspected,” under the “Evaluation and Technical Basis” heading of the attached aging management program, “XI.XXXX Monitoring of Neutron Absorbing Materials other than Boraflex,” add the following sentence: “Where it can be shown that for a specific material and environment test results are not site-specific, the use of shared industry coupon testing results is acceptable.” 

No changes to the Lincorporated. The Lguidance as to one managing the effectperiod of extended oneutron-absorbing scomponents; howevnot preclude a licenfrom proposing and approaches for managing. 

14 

Nuclear Energy Institute 

Letter dated December 31, 

2009 

(ML100060387) 

In item four, “Detection of Aging Effects,” under the “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 situ testing. Such testing includes measurement of boron areal density, geometric changes in the material (blistering, pitting, and bulging), detection of gaps 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. 

Comment incorpora
- E-7 - 

Comment 

No. 

Comment Source 

(ADAMS Accession No.) Comment on Draft LR-ISG-2009-01 NRC Sta

15 

Nuclear Energy Institute 

Letter dated December 31, 

2009 

(ML100060387) 

Regarding item four, “Detection of Aging Effects,” under the “Evaluation and Technical Basis” heading of the attached aging management program, “XI.XXXX Monitoring of Neutron Absorbing Materials other than Boraflex,” provide the basis for a testing frequency of a maximum of 10 years. Use of operating experience should be permitted to allow licensees to determine the appropriate inspection frequency requirements. Therefore, delete the words, “with a maximum of 10 years” from the last sentence of this item. 

The 10-year maximinspections ensures inspection and testinacquired during the operation. This percurrent industry inserequirements for counder 10 CFR 50.55the American SocieEngineers Code. In the aging managedescription, the “Deitem has been clarifapplicants should deinspection and testinoperating experiencfrequency is not to e
- E-8 - 

Comment 

No. 

Comment Source 

(ADAMS Accession No.) Comment on Draft LR-ISG-2009-01 NRC Sta

16 

Nuclear Energy Institute 

Letter dated December 31, 

2009 

(ML100060387) 

Concerning the second sentence of item seven, “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, (2) those licensees with 10 CFR 50.68(b)(4) as their licensing basis comply with the regulatory requirement 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.” 

Comment incorpora

17 

Nuclear Energy Institute 

Email dated January 6, 2010 

(ML100280648) 

The term “Carborundum” is used rather than something more generic. Carborundum is the manufacturer of a neutron-absorber which consists of boron-carbide in a phenol formaldehyde resin. Other manufacturers (e.g., ESK) manufacture boron-carbide in a phenolic resin, which is a similar material. The 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). 

No changes to the Lincorporated. Carboin the LR-ISG either neutron-absorbing mdescription of plant-experience for carbo
- E-9 - 

Comment 

No. 

Comment Source 

(ADAMS Accession No.) Comment on Draft LR-ISG-2009-01 NRC Sta

18 

Nuclear Energy Institute 

Email dated January 6, 2010 

(ML100280648) 

The LR-ISG uses the term, “Region 1 Fuel Storage Racks.” This is specific rack defined by a specific station. This term should be better defined, for example, use “fuel storage racks that receive freshly discharged fuel,” or something similar. 

The definition or regclarified as “high reafuel,” as defined in EInstitute’s “HandbooMaterials for Spent Storage Application