ML121660156 

UNITED STATES 

NUCLEAR REGULATORY COMMISSION 

OFFICE OF NUCLEAR REACTOR REGULATION 

OFFICE OF NEW REACTORS 

OFFICE OF FEDERAL AND STATE MATERIALS 

AND ENVIRONMENTAL MANAGEMENT PROGRAMS 

WASHINGTON, DC 20555-0001 

August 10, 2012 

NRC INFORMATION NOTICE 2012-13: BORAFLEX DEGRADATION SURVEILLANCE 

PROGRAMS AND CORRECTIVE ACTIONS IN 

THE SPENT FUEL POOL 

ADDRESSEES

All holders of an operating license or construction permit for a nuclear power reactor under 

Title 10 of the Code of Federal Regulations (10 CFR) Part 50, “Domestic Licensing of 

Production and Utilization Facilities,” including those that have permanently ceased operations 

and have spent fuel stored in the spent fuel pool. 

All holders of or applicants for a combined license issued under 10 CFR Part 52, “Licenses, 

Certifications, and Approvals for Nuclear Power Plants.” 

PURPOSE

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice (IN) to inform 

addressees on the continuing issue of degradation of the neutron absorbing material Boraflex in 

spent fuel storage racks. The NRC expects that recipients will review the information for 

applicability to their facilities and consider actions, as appropriate, to avoid similar problems. 

Suggestions contained in this IN are not NRC requirements; therefore, no specific action or 

written response is required. 

DESCRIPTION OF CIRCUMSTANCES

Turkey Point Nuclear Plant, Unit 3

In 2001, a condition prohibited by Turkey Point Nuclear Plant (TPNP), Unit 3 technical 

specifications (TS) occurred when the areal density of boron in portions of a Boraflex panel in 

the Unit 3 spent fuel pool (SFP) was measured to be less than the value used in the licensing 

basis analysis. The areal density of the Boraflex panels was a critical design feature of the 

spent fuel storage racks. Since 2001, Florida Power & Light Company (FPL) had found 

degradation of Boraflex panels greater than assumed in safety reviews for the SFP and 

incrementally took steps to assure the subcritical storage of fuel. 

As part of a review in 2010, the NRC staff identified that FPL incorrectly used the combined 

areal density of the panels in a single cell to determine compliance with the effective neutron 

multiplication factor (keff) requirements in its TS. When the areal density of a single panel 
IN 2012-13 

Page 2 of 4 

degraded below the value assumed in the licensing basis analysis described in the updated final 

safety analysis report, the licensee was not in compliance with its TS. 

In addition, it was identified that the licensee failed to implement effective corrective actions as 

required by 10 CFR Part 50, Appendix B, Criterion XVI, “Corrective Action.” Despite SFP 

management controls which prohibited the placement of fuel assemblies into SFP cells with 

greater than 50 percent Boraflex degradation, two cells were found to have stored fuel 

assemblies in them. Although the licensee had a neutron absorber monitoring program, the 

program was ineffective at identifying and mitigating degradation of the Boraflex panels in the 

SFP. This unidentified and unmitigated degradation posed a potential safety concern because it 

reduced the margin to criticality. 

The licensee implemented compensatory measures to provide reasonable assurance that the 

SFP remained subcritical until the licensee could implement an approved license amendment to 

eliminate the reliance on Boraflex as a neutron absorber. The NRC issued a confirmatory 

action letter (CAL), dated February 19, 2010, containing the licensee’s compensatory measures. 

In a follow-up inspection report, the NRC staff confirmed that the licensee had implemented the 

CAL commitments to address the degraded neutron absorbers in the spent fuel storage racks. 

The NRC staff subsequently concluded that the licensee had reestablished compliance with the 

license requirements for the spent fuel storage racks. 

Additional information is available in the following documents: 

(1) Licensee Event Report 05000250/2010-001-02, “Spent Fuel Storage Design Feature 

Assumption are Exceeded,” dated June 7, 2011, (Agencywide Documents Access and 

Management System (ADAMS) Accession No. ML11174A040). 

(2) “Turkey Point Nuclear Plant – NRC Integrated Inspection Report 05000250/2010008,” 

dated March 11, 2010 (ADAMS Accession No. ML100700661). 

(3) “Turkey Point Nuclear Plant Unit 3 - NRC Inspection procedures 95001 Supplemental 

and 92702 Follow up – Inspection Report 05000250/2010-010,” dated January 6, 2011 

(ADAMS Accession No. ML110060770). 

(4) “License Amendment Request – Spent Fuel Pool Boraflex Remedy,” dated January 27, 

2006 (ADAMS Accession No. ML060900250). 

 

Peach Bottom Atomic Power Station, Unit 2 

In 2010, Peach Bottom Atomic Power Station (PBAPS) performed an operability determination 

(OD) that concluded that sufficient margin to criticality in its SFP would be maintained until 

2014. However, the NRC’s review of the OD concluded that the licensee had not accurately 

projected the rate of Boraflex degradation and had used several nonconservative assumptions 

in the analysis. The licensee performed a reanalysis and determined that several Boraflex 

panels had degraded below the TS requirements as early as the fourth quarter of 2008. As a 

result, contrary to 10 CFR Part 50, Appendix B, Criterion XVI, “Corrective Actions,” the licensee 

had not implemented corrective actions to prevent the Boraflex panels from degrading below the 

TS requirements. Although the licensee had a neutron absorber monitoring program, the 

program did not adequately monitor and manage degradation of the Boraflex panels in the SFP 

to ensure sufficient margin to criticality was maintained. This unidentified and unmitigated 

degradation posed a potential safety concern because it reduced the margin to criticality. 
IN 2012-13 

Page 3 of 4 

In June 2011, the licensee relocated 201 fuel assemblies from the storage cells with the highest 

Boraflex degradation. Additionally, the licensee put administrative controls in place to restrict 

the usage of rack locations containing degraded Boraflex. 

Additional information is available in the following documents: 

(1) Licensee Event Report 05000277/2011-002-00, “Condition Prohibited by Technical 

Specifications due to Degraded Spent Fuel Pool Racks Boraflex® Panels” dated July 29, 

2011 (ADAMS Accession No. ML11213A262). 

(2) “License Amendment Request - Use of Neutron Absorbing Inserts in Units 2 and 3 Spent 

Fuel Pool Storage Racks,” dated November 3, 2011 (ADAMS under Accession No. 

ML113081441). 

BACKGROUND

Generic Letter 96-04, “Boraflex Degradation in Spent Fuel Pool Storage Racks,” highlights 

industry operational experience with the degradation of Boraflex that had been previously 

addressed by the NRC IN 87-43, "Gaps in Neutron-Absorbing Material in High-Density Spent 

Fuel Storage Racks," September 8, 1987; IN 93-70, "Degradation of Boraflex Neutron Absorber 

Coupons," September 10, 1993; and IN 95-38, "Degradation of Boraflex Neutron Absorber in 

Spent Fuel Storage Racks," September 8, 1995. Additionally, Generic Letter 96-04 requested 

each licensee crediting Boraflex to provide the NRC with its plan to manage the degradation. 

Since the issuance of Generic Letter 96-04, there has been additional operating experience with 

neutron absorbing materials (other than Boraflex) degrading while in the spent fuel storage 

racks. IN 09-26, “Degradation of Neutron-Absorbing Materials in the Spent Fuel Pool,” 

October 28, 2009, addresses the degradation of the materials Boral and Carborundum. 

IN 09-26 emphasizes that to prevent noncompliance with SFP criticality requirements, it is 

important to know the condition of the neutron absorbing material in the SFP and monitor the 

SFP for any indications that the material may be degrading. 

DISCUSSION

Fuel stored in the spent fuel storage racks must be maintained subcritical in accordance with 

the requirements in 10 CFR 50.68(b)(4). This IN is to inform licensees about the importance of 

effective surveillance programs and corrective actions when dealing with Boraflex degradation 

in the SFP. The occurences at TPNP and PBAPS are recent examples where the surveillance 

programs and corrective actions were not effective in dealing with Boraflex degradation. 

The recent operating experience with neutron absorber degradation, like that of Boraflex, 

demonstrates the need for effective material surveillance programs. These instances highlight 

that ineffectual monitoring and corrective actions can lead to unidentified and unmitigated 

degradation that may challenge the subcritical margin for the SFP. An effective surveillance 

and monitoring program for neutron absorber materials degradation is essential to manage the 

degradation before it results in a potential safety concern. 
IN 2012-13 

Page 4 of 4 

CONTACT

This IN requires no specific action or written response. Please direct any questions about this 

matter to the technical contacts listed below or the appropriate NRC project manager. 

/RA/ /RA/ 

Timothy J. McGinty, Director Larry W. Camper, Director 

Division of Policy and Rulemaking Division of Waste Management 

Office of Nuclear Reactor Regulation and Environmental Protection 

 Office of Federal and State Materials and 

 Environmental Management Programs 

/RA by JLuehman for/ 

Laura A. Dudes, Director 

Division of Construction Inspection 

 and Operational Programs 

Office of New Reactors 

Technical Contacts: Christopher Hunt, NRR Matthew G. Yoder, NRR 

 301-415-1652 301-415-4017 

 E-mail: christopher.hunt@nrc.gov E-mail: matthew.yoder@nrc.gov

Note: NRC generic communications may be found on the NRC public Web site, 

http://www.nrc.gov, under NRC Library. 
IN 2012-13 

Page 4 of 4 

CONTACT

This IN requires no specific action or written response. Please direct any questions about this 

matter to the technical contacts listed below or the appropriate NRC project manager. 

/RA/ /RA/

Timothy J. McGinty, Director Larry W. Camper, Director 

Division of Policy and Rulemaking Division of Waste Management 

Office of Nuclear Reactor Regulation and Environmental Protection 

 Office of Federal and State Materials and 

 Environmental Management Programs 

/RA by JLuehman for/

Laura A. Dudes, Director 

Division of Construction Inspection 

 and Operational Programs 

Office of New Reactors 

Technical Contacts: Christopher Hunt, NRR Matthew G. Yoder, NRR 

 301-415-1652 301-415-4017 

 E-mail: christopher.hunt@nrc.gov E-mail: matthew.yoder@nrc.gov

Note: NRC generic communications may be found on the NRC public Web site, 

http://www.nrc.gov, under NRC Library. 

ADAMS Accession No.: ML121660156 *via e-mail TAC ME8326 

OFFICE NRR/ESGB NRR/ESGB Tech Editor* BC:NRR/ESGB D:NRR/DE 

NAME CHunt MYoder QTE GKulesa PHiland 

DATE 6/14/2012 6/18/2012 6/26/2012 6/19/2012 6/21/2012 

OFFICE BC:NRR/SRXB BC:FSME/RDB LA:NRR/PGCB PM:NRR/PGCB BC:NRR/PGCB 

NAME AUlses BWatson CHawes BPurnell DPelton 

DATE 7/10/2012 7/11/2012 7/12/2012 7/12/2012 7/31/2012 

OFFICE LA:NRR/PGCB* D:NRO/DCIP D:FSME/DWMEP D:NRR/DPR 

NAME CHawes LDudes (JLuehman for) LCamper TMcGinty 

DATE 7/31/2012 8/3/2012 8/9/2012 8/10/2012 

OFFICIAL RECORD COPY