NRC CONCLUDES DAVIS-BESSE NUCLEAR PLANT SAFE TO RESTART AND

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NRC CONCLUDES DAVIS-BESSE NUCLEAR PLANT SAFE TO RESTART AND ISSUES CONFIRMATORY ACTION LETTER
The U.S. Nuclear Regulatory Commission has determined that the operators of the Davis-Besse nuclear power plant, FirstEnergy Nuclear Operating Corp. (FENOC) have provided reasonable assurance that the shield building is capable of performing its safety functions and that the utility can proceed with restarting the plant. The NRC’s independent assessmentevaluated a wide range of information such as technical details ranging from the size of thecracks, the utility’s sampling and testing of the concrete in the building to determine the extent ofthe cracks, and its structural analysis. The plant is located in Oak Harbor, Ohio about 40 milessoutheast of Toledo.The NRC will hold a public meeting in which FENOC will discuss their technicalanalysis and explain why the plant is safe to continue to operate with the cracks in the shield building. The meeting will take place in the near future with details to be issued once finalized.However, the NRC has issued a Confirmatory Action Letter (CAL-attached) to the operator of the plant, FENOC. The CAL details and confirms FENOC’s agreement to take certain actions to monitor and ensure the cracks in the shield building continue to not adverselyimpact safety going forward. The NRC will review and evaluate FENOC’s actions in responseto the CAL in order to make sure they are thorough and complete. The FENOC commitments to the NRC include:- Determine and provide the root cause of the cracks in the shield building, correctiveactions, and develop a long-term monitoring program.- Select multiple areas in the shield building that have no cracks but are adjacent toknown cracks to determine whether the area of the cracks has spread.- Perform additional analysis in known cracked areas to determine whether the width ofthe cracks has increased.
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Even though the NRC has concluded the shield building can perform its safety functions, the NRC will continue to inspect whether the shield building in its current condition meets all design requirements in the plant’s license. Failure to meet the commitments in the CAL may result in additional regulatory action if the utility does not provide reasonable assurance that the NRC can rely on the FENOC to meetthe NRC’s requirements and protect public health and safety.On Oct. 10 the NRC was informed by FENOC that while conducting work to replace theDavis-Besse reactor vessel head its workers identified cracks in the shield building. The shield building is a 2.5 foot thick reinforced concrete building that surrounds a 1.5 inch thick steelcontainment vessel that encloses the reactor. The two buildings are separated by a 4.5 footspace.The NRC will issue an inspection report documenting its review of this issue and theagency’s conclusions 45 days after the inspection is complete.###News releases are available through a free listserv subscription or by clicking on theEMAIL UPDATES link on the NRC homepage (www.nrc.gov). E-mail notifications are sent tosubscribers when news releases are posted to NRC's website.
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UNITED STATESNUCLEAR REGULATORY COMMISSIONREGION III2443 WARRENVILLE ROAD, SUITE 210LISLE, IL 60532-4352December 2, 2011CAL No. 3-11-001Mr. Barry AllenSite Vice PresidentFirstEnergy Nuclear Operating CompanyDavis-Besse Nuclear Power Station5501 North State Route 2, Mail Stop A-DB-3080Oak Harbor, OH 43449-9760SUBJECT:CONFIRMATORY ACTION LETTER - DAVIS-BESSE NUCLEARPOWER STATIONDear Mr. Allen:This letter confirms commitments by FirstEnergy Nuclear Operating Company (FENOC)regarding the identification of cracks in the reinforced concrete shield building at the Davis-Besse Nuclear Power Station. During the recent mid-cycle outage to replace the reactorvessel closure head, which began on October 1, 2011, FENOC discovered laminar cracking in the safety-related shield building of the containment system while performing hydrodemolition operations. Based on an evaluation of FENOC’s extent of condition and technical analysis ofthe Davis-Besse shield building laminar cracking, the NRC staff concluded that FENOCprovided reasonable assurance that the shield building is capable of performing its safetyfunctions. In order to provide continued long-term confidence, FENOC has agreed in telephoneconversations between you, Steven West, and Steven Reynolds, on November 21, 2011; a followup telephone conversation between you and Jamnes Cameron on November 22, 2011; ina FENOC commitment letter dated November 23, 2011 (ML11329A033); and a telephone conversation between you and Steven Reynolds on December 2, 2011, to the following actions(both completed and planned):1. FENOC will provide the results of the root cause evaluation and corrective actions to theNRC, including any long-term monitoring requirements, by February 28, 2012.2. FENOC will identify four shield building locations, which were core bored during thisevaluation, for examination. These uncracked locations will be directly adjacent tolocations that have been confirmed to be cracked. The four uncracked locations, asdesignated on FENOC drawing C-111A, are:a. adjacent to a flute shoulder [S9-666.0-12];b. in a flute area [F4-1-666.0-3];c. adjacent to Main Steam Line penetration 39 [S7-652.0-6.5]; andd. adjacent to Main Steam Line penetration 40 [S9-650.0-9].
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B. Allen-2-3. FENOC will examine the four core bore locations from Commitment 2 above with a borescope to verify cracking has not migrated to these core bores located in solid (i.e., uncracked) concrete, within 90 days following plant restart (Mode 2) from the2011 mid-cycle outage.4. FENOC will examine the crack interface to identify any changes by performing a corebore in a known crack area within the Main Steam Line Room, within 90 days followingplant restart (Mode 2) from the October 2011 mid-cycle outage.5. FENOC will identify two additional shield building locations, which were core bored during this evaluation, for examination. These uncracked locations will be directlyadjacent to locations that have been confirmed to be cracked. The two uncrackedlocations, as designated on FENOC drawing C-111A, are:a. in a flute area [F5-777.0-4]; andb. adjacent to a flute shoulder [S2-783.5-4.0].6. FENOC will examine the four core bore locations from Commitment 2 along with the two core bore locations from Commitment 5 with a borescope to verify cracking hasnot migrated to these core bores located in solid (i.e., uncracked) concrete, during the seventeenth refueling outage currently scheduled to commence in 2012.7. FENOC will examine the crack interface to identify any changes by examining eitherexisting core bore locations with known cracks, or by performing a core bore in a similararea:a. adjacent to a flute shoulder [S9-666.0-11];b. near the top of the shield building [S9-785-22.5]; andc. adjacent to Main Steam Line penetration [core bore from Commitment 4].during the seventeenth refueling outage currently scheduled to commence in 2012.Pursuant to Section 182 of the Atomic Energy Act, 42 U.S.C. 2232, you are required to:1) Notify me immediately if your understanding differs from that set forth above;2) Notify me if for any reason you cannot complete the actions and commitments within the specified schedule and advise me in writing of your modified schedule in advance of the change; and3) Notify me in writing when you have completed the actions and commitments addressed in this Confirmatory Action Letter.Issuance of this Confirmatory Action Letter does not preclude issuance of an Order formalizingthe above commitments or requiring other actions on the part of FENOC, nor does it