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Revision as of 01:41, 2 April 2018
ML12248A106 | |
Person / Time | |
---|---|
Site: | San Onofre ![]() |
Issue date: | 09/24/2012 |
From: | Broaddus D A Division of Operating Reactor Licensing |
To: | Papaila D - No Known Affiliation |
Gibson L K | |
Shared Package | |
ML12248A100 | List: |
References | |
G20120547, LTR-12-0366, SECY-2012-0386, TAC ME9235, TAC ME9236 | |
Download: ML12248A106 (3) | |
Text
September 24, 2012
Ms. Dawn Papaila P.O. Box 4451 Idyllwild, CA 92549
Dear Ms. Papaila:
On behalf of the U.S. Nuclear Regulatory Commission (NRC), I am responding to your letter to Chairman Gregory B. Jaczko, dated July 13, 2012, in which you conveyed concerns about the safety of the San Onofre Nuclear Generating Station (SONGS).
As you noted in your letter, SONGS, Units 2 and 3, are currently shut down due to excessive steam generator tube wear. On March 15, 2012, the NRC sent an augmented inspection team (AIT) to the site in response to the January 31, 2012, steam generator tube leak in Unit 3 and the subsequent discovery of significant tube-to-tube wear on both of the Unit 3 steam generators and significantly less tube-to-tube wear on one of the two Unit 2 steam generators.
For several months, this team of NRC inspectors, with assistance from other NRC experts, has been closely following the licensee's actions to evaluate the causes of the excessive tube wear and to develop corrective actions to prevent further tube degradation. On June 18, 2012, NRC personnel met with representatives of Southern California Edison (SCE) in San Juan Capistrano, California, to present the NRC's issues and observations resulting from the AIT inspection. As discussed in that meeting, the NRC understands the steam generator thermal hydraulic conditions that resulted in the tube degradation, that these conditions were not accurately predicted during design, and that the licensee is evaluating and developing additional actions to fix and prevent any additional tube-to-tube degradation due to excessive vibration.
On March 27, 2012, the NRC issued a Confirmatory Action Letter (CAL) to SCE, identifying the specific actions the licensee has committed to take prior to returning the units to power operation. The CAL can be viewed on the NRC Web site, http://www.nrc.gov, in the Agencywide Documents Access and Management System (ADAMS), at Accession No. ML12087A323. Under the terms of the CAL, each unit will remain shut down until the licensee provides its written evaluations and responses to all of the CAL items for that unit. The NRC will perform additional related inspections and reviews of that information. The NRC will not allow the plant to restart if we are not satisfied it can be operated without undue risk to public health and safety. The NRC will take as much time as needed in determining the appropriate actions to ensure the safety of the public, and will communicate its determinations to SCE regarding the restart of SONGS, Units 2 and 3, in writing.
In your letter, you mentioned a report concerning the effect of a major seismic event on sensors in emergency diesel generators. The NRC is aware of this issue and is completing an inspection related to it. The results of the inspection will be docketed in a future inspection report.
Seismic and flooding hazards are being addressed for all U.S. nuclear plants as part of the lessons learned from the Fukushima Dai-ichi event in Japan. In March 2011, the NRC D. Papaila - 2 - established a senior level agency Near-Term Task Force to conduct a methodical and systematic review of NRC processes and regulations to determine additional improvements that could be made to the agency's regulatory system. In October 2011, the NRC staff provided its proposed plan of action and prioritization of the task force recommendations, including actions beyond those recommended in the task force report. That plan is publicly available in ADAMS, at Accession No. ML11272A111, and on the NRC Web site at:
http://www.nrc.gov/readingrm/doc-collections/commission/secys/2011/2011-0137scy.pdf. The agency has been proceeding to address all Tier 1 recommendations from the Near-Term Task Force report. Tier 1 recommendations are those recommendations which the NRC staff determined should be started without unnecessary delay. On March 12, 2012, the NRC issued three orders requiring nuclear power plants to implement safety enhancements related to (1) mitigating strategies to respond to extreme natural events resulting in the loss of electric power at plants, (2) ensuring reliable hardened containment vents (applicable only to boiling-water reactors with Mark 1 or Mark 2 containments), and (3) enhancing spent fuel pool instrumentation. All operating nuclear power plants are required to begin implementation of the safety enhancements and to complete implementation within two refueling outages, or by December 31, 2016, whichever comes first. In addition, the NRC issued a formal request for information to all operating reactor licensees to (1) reevaluate seismic and flooding hazards (including tsunami hazards) at their sites using applicable current methods and information, (2) conduct walkdowns of their facilities to ensure protection against the hazards in their current design basis, and (3) reevaluate their emergency communications systems and staffing levels. The NRC will evaluate SCE's response to the request for information in determining the need for plant modifications or further enhancements to address seismic and flooding hazards at SONGS. These orders and requests for information, as well as other information on the agency's response to the Fukushima event, are accessible on the NRC Web site at http://www.nrc.gov/reactors/operating/ops-experience/japan-info.html. Thank you for conveying your concerns about these matters.
Sincerely, /RA/
Douglas A. Broaddus, Chief San Onofre Special Projects Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-361 and 50-362
D. Papaila - 2 - established a senior level agency Near-Term Task Force to conduct a methodical and systematic review of NRC processes and regulations to determine additional improvements that could be made to the agency's regulatory system. In October 2011, the NRC staff provided its proposed plan of action and prioritization of the task force recommendations, including actions beyond those recommended in the task force report. That plan is publicly available in ADAMS, at Accession No. ML11272A111, and on the NRC Web site at:
http://www.nrc.gov/readingrm/doc-collections/commission/secys/2011/2011-0137scy.pdf.
The agency has been proceeding to address all Tier 1 recommendations from the Near-Term Task Force report. Tier 1 recommendations are those recommendations which the NRC staff determined should be started without unnecessary delay. On March 12, 2012, the NRC issued three orders requiring nuclear power plants to implement safety enhancements related to (1) mitigating strategies to respond to extreme natural events resulting in the loss of electric power at plants, (2) ensuring reliable hardened containment vents (applicable only to boiling-water reactors with Mark 1 or Mark 2 containments), and (3) enhancing spent fuel pool instrumentation. All operating nuclear power plants are required to begin implementation of the safety enhancements and to complete implementation within two refueling outages, or by December 31, 2016, whichever comes first. In addition, the NRC issued a formal request for information to all operating reactor licensees to (1) reevaluate seismic and flooding hazards (including tsunami hazards) at their sites using applicable current methods and information, (2) conduct walkdowns of their facilities to ensure protection against the hazards in their current design basis, and (3) reevaluate their emergency communications systems and staffing levels. The NRC will evaluate SCE's response to the request for information in determining the need for plant modifications or further enhancements to address seismic and flooding hazards at SONGS. These orders and requests for information, as well as other information on the agency's response to the Fukushima event, are accessible on the NRC Web site at http://www.nrc.gov/reactors/operating/ops-experience/japan-info.html.
Thank you for conveying your concerns about these matters. Sincerely, /RA/ Douglas A. Broaddus, Chief San Onofre Special Projects Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-361 and 50-362 DISTRIBUTION: G20120547/LTR-12-0366/EDATS: SECY-2012-0385 PUBLIC LPL4 Reading RidsAcrsAcnw_MailCTR Resource RidsEdoMailCenter Resource RidsNrrDorl Resource RidsNrrDorlLpl4 Resource RidsNrrLAJBurkhardt Resource RidsNrrMailCenter Resource RidsNrrOd Resource RidsNrrPMSanOnofre Resource RidsOcaMailCenter Resource RidsOgcRp Resource RidsOpaMail Resource RidsRgn4MailCenter Resource ADAMS Accession Nos.: Pkg ML12248A100; Incoming ML12209A274; Response ML12248A106 OFFICE NRR/LPL4/PM NRR/LPL4/LA NRR/LPL4/PM NRR/LPL2-2/BC NAME LKGibson JBurkhardt JRHall DBroaddus DATE 9/13/12 9/12/12 9/20/12 9/24/12 OFFICIAL RECORD COPY