ML12251A102
| ML12251A102 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 09/07/2012 |
| From: | Stephanie Coffin Division of Operating Reactor Licensing |
| To: | Horn S, Morgan G Bellefonte Efficiency & Sustainability Team (BEST), Mothers Against Tennessee River Radiation (MATRR) |
| Orf T | |
| Shared Package | |
| ML12244A058 | List: |
| References | |
| G20120602, LTR-12-0414, SECY-201-0408, TAC ME9228, TAC ME9229, TAC ME9230 | |
| Download: ML12251A102 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 September 7,2012 Mr. Stewart Horn and Mr. Gary Morgan Bellefonte Efficiency & Sustainability Team Mothers Against Tennessee River Radiation P.O. Box 241 Scottsboro, AL 35768
SUBJECT:
G20120602- BEST/MATRR CONCERNS RELATED TO BROWNS FERRY NUCLEAR PLANT (TAC NOS ME9228, ME9229, AND ME9230)
Gentlemen:
This letter is in response to correspondence provided to the Nuclear Regulatory Commission (NRC) by letter dated July 31,2012. In that letter, your organization requested that the "NRC fulfill their mandate to protect the public ... by shutting down these extremely dangerous GE Mark I reactors." The letter also mentioned several areas that it contends forms the basis for "considerable cause for concern," as it relates to the Tennessee Valley Authority's Browns Ferry Nuclear Plant (BFN). These areas, in general, are the condition of the reactor pressure vessel (RPV), the reactor vessel core shroud, and protection from natural events as it relates to spent fuel storage. The information provided in the letter appears to fall into one of the following categories: (1) the information is related to descriptions of conditions or issues for which the BFN units and other boiling-water reactors (BWRs) are explicitly designed to mitigate; (2) the information has been reviewed by the NRC staff and the NRC staff has determined that the design is sufficiently robust to address the concern; or (3) BFN has been acceptably modified to ensure continued safe operation of the facility.
The RPV is one of three primary barriers, along with the fuel cladding and the primary containment, to fission product release. It was inferred in your correspondence, that the number of scrams experienced at the BFN facilities have prematurely aged the RPVs and as a result the RPVs "may now be in a weakened state." The NRC established in Part 50 to Title 10 to the Code of Federal Regulations, various requirements and safety limits to ensure that the RPV maintains the capability to prevent fission product release. These conservatively established requirements and limits are monitored during scrams and other transients to ensure that significant degradation is identified and addressed in a timely fashion to maintain safety.
Should the BFN units exceed the safety limits, the units would be required to shutdown and would not be allowed to restart until the NRC was assured of the ability of the affected systems, structures, and components to mitigate the consequences of the design-basis accident. The NRC staff is not aware of any instances where a safety limit, intended to protect barriers to fission product release, has been identified as being exceeded. Additionally, the BFN units underwent a review of the aging affects of passive components as part of the license renewal review completed in 2006. The issue of RPV embrittlement was part of the review and no issues of premature aging were identified.
S. Horn and G. Morgan -2 Required monitoring programs have led to the identification for the potential degradation in RPV components over the years in some BWRs. For example, in 1993 cracking of the core shroud (the stainless steel cylinder that serves to direct the flow of water inside the RPV) was identified in a facility. The NRC staff required inspections of the core shroud in all BWRs and repairs, if necessary. Those inspections were performed at BFN and repairs were not indicated.
The response to natural phenomena, such as tornados, is also a general design requirement for the BFN facility. As stated in the BFN Updated Final Safety Analysis Report, "[t]he plant equipment which is important to safety was designed to permit safe plant operation and to accommodate all design basis accidents without loss of capability for the appropriate environmental phenomena at the site. The environmental resistance capability of these designs was based on the relevant site historical data, with suitable margin allowances for uncertainties." Additionally, with regard to your comments on the subjects of hardened vents and the impact of natural phenomena on spent fuel pools, these were both described in the agency's Fukushima Near Term Task Force report to the Commission that provided recommendations for additional actions, including enhancing spent fuel pool makeup capability and level instrumentation. The events at Fukushima were and continue to be reviewed by the NRC staff. (Please see the web pages at http://www.nrc.gov/reactors/operating/ops experience/japan/plants/bf1.html for more information.)
Many of the concerns suggested in your correspondence are issues that have been previously reviewed and appropriate corrective measures directed commensurate with their significance.
The NRC's regulatory framework was established to allow for monitoring of needed systems, structures, and components to ensure that adverse conditions could be promptly identified and corrected. The NRC staff has established regulations to ensure margin in the design of the facilities. Resident inspectors onsite at BFN, as well as specialist inspectors, are routinely reviewing the status of these operating units. Identified challenges to the design of BFN, like any facility, are carefully reviewed and appropriate mitigating measures directed. Should information suggest that challenges as a result of operation, age, or nature have or will result in the inability to safely operate these units, the NRC will take those measures necessary to ensure the continued health and safety of the public and the environment.
If you have any further questions or concerns, please feel free to contact Ms. Eva Brown at 301-415-2315.
Sincerely, Stephanie M. Coffin, Deputy Director Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-259, 50-260, and 50-296 cc: Distribution via Listserv
S. Horn and G. Morgan -2 Required monitoring programs have led to the identification for the potential degradation in RPV components over the years in some BWRs. For example, in 1993 cracking of the core shroud (the stainless steel cylinder that serves to direct the flow of water inside the RPV) was identified in a facility. The NRC staff required inspections of the core shroud in all BWRs and repairs, if necessary. Those inspections were performed at BFN and repairs were not indicated.
The response to natural phenomena, such as tornados, is also a general design requirement for the BFN facility. As stated in the BFN Updated Final Safety Analysis Report, "[t]he plant equipment which is important to safety was designed to permit safe plant operation and to accommodate all design basis accidents without loss of capability for the appropriate environmental phenomena at the site. The environmental resistance capability of these designs was based on the relevant site historical data, with suitable margin allowances for uncertainties." Additionally, with regard to your comments on the subjects of hardened vents and the impact of natural phenomena on spent fuel pools, these were both described in the agency's Fukushima Near Term Task Force report to the Commission that provided recommendations for additional actions, including enhancing spent fuel pool makeup capability and level instrumentation. The events at Fukushima were and continue to be reviewed by the NRC staff. (Please see the web pages at http://www.nrc.govlreactors/operating/ops experience/japan/plants/bf1.html for more information.)
Many of the concerns suggested in your correspondence are issues that have been previously reviewed and appropriate corrective measures directed commensurate with their significance.
The NRC's regulatory framework was established to allow for monitoring of needed systems, structures, and components to ensure that adverse conditions could be promptly identified and corrected. The NRC staff has established regulations to ensure margin in the design of the facilities. Resident inspectors onsite at BFN, as well as specialist inspectors, are routinely reviewing the status of these operating units. Identified challenges to the design of BFN, like any facility, are carefully reviewed and appropriate mitigating measures directed. Should information suggest that challenges as a result of operation, age, or nature have or will result in the inability to safely operate these units, the NRC will take those measures necessary to ensure the continued health and safety of the public and the environment.
If you have any further questions or concerns, please feel free to contact Ms. Eva Brown at 301-415-2315.
Sincerely, IRA!
Stephanie M. Coffin, Deputy Director Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-259, 50-260, and 50-296 cc: Distribution via Listserv DISTRIBUTION: G20120602/EDATS: SECY*2012*0408 PUBLIC LPL2 RtF RidsAcrsAcnw_MailCTR Resource RidsOpaMail Resource RidsEdoMailCenter Resource RidsOgcMailCenter Resource RidsOgcRp Resource RidsNrrDori Resource RidsSecyMailCenter Resource RidsOcaMaliCenter Resource RidsNrrLABClayton Resource RidsNrrDorlLplll-2 Resource RidsNrrOd Resource RidsNrrMailCenter Resource RidsRgn2MailCenter Resource MBanic, NRR ADAMS Accession Nos. Pkg: ML12244Ao58; ncoming ML12229A439; Response ML12251A102 OFFICE DORUPM LPLII*2/LA OGC NLO DORUBC DORUDD NAME EBrown (TJO for) BClayton MLemoncelli JQuichocho SCoffin*
DATE 9/7/12 917112 9/6112 917112 917112 OFFICIAL RECORD COpy