ML20198H532
| ML20198H532 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 09/16/1997 |
| From: | Meisner M Maine Yankee |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| MJM-97-15, MN-97-105, NUDOCS 9709190037 | |
| Download: ML20198H532 (5) | |
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MaineYankee AELI ABG ELEeTRiclTY SINCE 1972 329 BATH ROAD
- BRUNSWICK, MAINE 04011 * (207) 798-4100 L
8 September 16,1997 MN-97105 MJM-97-15 UNITED STATES NUCLEAR REGULATORY COMMISSION Attention: Document Control Desk Washington, DC 20555
References:
(a) License No. DPR-36 (Docket No. 50-309)
(b) Letter: M. B. Sellman to USNRC; Certifications of Permanent Cessation i
of Power Operation and Permanent Removal of Fuel from the Reactor; MN-97-89, dated August 7,1997
Subject:
10 CFR 50.63, Station Blackout Gentlemen:
In Reference (b), Maine Yankee informed the USNRC that the Board of Directors of Maine Yankee had decided to permanently cease operations at the Maine Yankee Plant and that the fuel had been permanendy removed from the reactor. In accordance with 10CFR50.82(a)(2), the certifications in the letter modified the Maine Yankee license to permanently withdraw Maine Yankee's authority to operate the reactor and place fuel in the reactor vessel. As a consequence of these certifications, the nature of Maine Yankee's compliance with the Station Blackout Rule has changed.
The Station Blackout Rule,10 CFR 50.63(a)(1), requires that nuclear power plants licensed to operate be able to withstand for a specified duration the effects of a station blackout as defined in 10CFR50.2. Regalatory Guide 1.155 defines the specified duration as up to sixteen hours, depending on the plant specific design and site characteristics.10 CFR 50.63(a)(2) indicates that the purpose of the rule is "...to ensure that the core is cooled and appropriate containmc nt integrity is maintained in the event of a station blackout of a specified duration." 10CFR50.2, in the defimition of station blackout, and 10CFR50.63(c)(2) indicate that safe shutdown must be able to be achieved and maintained, in the event of a station blackout during power operation, for the required coping period. 10CFR50.2 ext.iicitly defines safe shutdown for station blackout to be those shutdown conditions specified in plant technical specifications as Hot Standby or Hot shutdown, as appropriate. The certifications ofpermanent Cessation of Operation and Removal of Fuel from the Reactor Yessel prohibit entry into those technical specification shutdown conditions and all operatin!. conditions from which those shutdow i conditions could be achieved, in a permanently defueled condition, Maine Yankee is in compliar.ce with 10CFR50.63 since no reactor core remains
= in the vessel.
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9709190037 970916 PDR ADOCK 05000309 P
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MaineYankee UNITED STATES NUCLEAR REGULATORY COhiMISSION h1N-97-105
, Attention: Document Control Desk Page Two Although not envisioned by the rule, Maine Yankee also meets the intent of 10CFR50.63 with respect to spent fuel storage. In the spent fuel pool, the fuel is maintained in a safe shutdown condition through the rack geometry and the spent fuel pool inventory and associated cooling system. NUREG/CR-6451 indicates that a total loss of cooling to the spent fuel pool would allow over 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> of boiloff before any spent fuel would be exposed and potentially damaged - well in excess of the coping period envisioned by 10CFR50.63. With the relocation of the fuel to the spent fuel pool, there is no longer a potential for a large offsite release of radioactivity from the containment building and, as noted by 10CFR50.54(o), comainment leak rate testing and, by extension, containment integrity for accident purposes is not an issue for permanently shut down facilities.
In the original response to 10CFR50.63, Maine Yankee installed equipment and developed procedures to provide for the required coping period. The procedures and equipment were designed to ensure that the plant could achieve and maintain a safe shutdown condition in the event of a station blackout with the reactor at power. The equipment and procedures are not, however, relevant to the safe storage of spent fuel in the spent fuel pool. As indicated above, with the plant in a permanently defueled condition, continued reliance on such equipment and procedures is not necessary for Maine Yankee to comply with either the letter or the spirit of the rule.
As a practical matter, during decommissioning, the equipment associated with prior commitments to station blackout must be dismantled, and the procedures associated with that equipment must be cancelled. To facilitate that process and to maintain a complete record on the docket, Maine Yankee is hereby withdrawing prior commitments and analyses associated with 10CFR50.63.
Although Maine Yankee is in compliance with 10CFR50.63, we recognize that NRC views on the relevance of '0CFR50.63 to permanently shutdown facilities have not been finalized. Should the NRC believe that exemption to 10CFR50.63 is required, please consider this submittal a request for an exemption as discussed in Attachment 1.
Ve trul[y s,
)
g r 'chae J. Meisner, Vice President h
Nuclear Safety & Regulatory Affairs Attachment c: Mr. Hubert Miller Mr. Richard A. Rasmussen Mr. Daniel H. Dorman Mr. Patrick J. Dostie Mr. Uldis Vanags Mr. Singh S. Bajwa
ATTACHMENT I REQUEST FOR EXEMPTION FROM TITLE 10 OF THE CODE OF FEDERAL REGULATIONS, PART 50.63 1.
REQUEST FOR EXEMPTION:
Maine Yankee hereby requests exemption from 10CFR50.63. Maine Yankee has decided to permanently cease operation of the Maine Yankee Plant. " Certification of Permanent Cessation of Operation and Removal of Fuel from the Reactor Vessel" has been docketed in accordance with 10CFR50.82.
IL BACKGROUND:
On August 7,1997, Maine Yankee submitted "Certho:ations for Permanent Cescation of Power l
Operation and Permanent Removal of Fuel from the Reactor" pursuant to 10CFR50.82(a)(1)(i) and (ii). With the docketing of this submittal, Maine Yankee was no longer authorized to operate the reactor or to place fuel in the reactor vessel in accordance with 10CFR50.82. In the defueled condition, there are no longer any credible design basis accidents associated with an operating plant from stanup through full power operation. The design basis accidents relative to a defueled facility are a small subset of those considered for an operating facility. This subset of design basis accidents would include the following: Fuel Handling Incident, Spent Fuel Cask Drop, and Radioactive Liquid Waste System Leaks and Failures.
10 CFR 50.63(a)(I) requires that nuclear power plants licensed to operate be able to withstand for a specified duration the effects of a station blackout as defined in 10CFR50.2. Regulatory Guide 1.155 defines the specified duration as up to sixteen hours, depending on the plant specific design and site characteristics 10 CFR 50.63(a)(2) indicates that the purpose of the rule is "...to ensure that the core is cooled and appropriate containment integrity is maintained in the event of a station blackout of a speciF.ed duration." 10 CFR 50.2, in the definition of station blackout, and 10CFR50.63(c)(2) indicate that safe shutdown must be able to be achieved and maintained, in the event of a station blackout which occurs during power opervion, for the required coping period.
10CFR50.2 explicitly defines safe shutdown for station blackout to be those shu"'own conditions specified in plant technical specifications as Hot Standby or Hot shutdown, as appropriate. The certifications of permanen' Cessation of Operation and Removal of Fuel from the Reactor Vessel prohibit entry into those technical specification shutdown conditions and all operating conditions from which those shutdown conditions could be achieved. In the spent fuel pool, the fuel is i
maintained in a safe condition through the rack geometry.nd the spent fuel pool inventory and associated cooling system. NUREG/CR-6451 indicates that a total loss of cooling to the spent fuel pool would allow over 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> of boil off before any spent fuel would be exposed and potentially damaged - well in excess of the coping period envisioned by 10CFR50.63. With the relocation of the fuel to the spent fuel pool, there is no longer a potential for a large offsite release of radioactivity from the containment building and, as noted by 10CFR50.54(o), containment leak rate testing and, by extension, containment integrity for accident purposes is not an issue for permanently shut down facilities.
4 In the original response to 10CFR50.63, hiaine Yankee installed equipment and developed procedures to provide for the required coping period. The equipment and procedures were designed to ensure that safe shutdown could be achieved and maintained in the event of a station blackout during power operation of the reactor. The equipment and procedures were not, however, related to the safe storage of spent fuel in the spent fuel pool. As indicated above, with the plant in a permanently defueled condition, continued reliance on the equipment and procedures is not necessary for Maine Yankee. Maine Yankee can withstand, without feel damage, a complete loss ofonsite and ofTsite AC power for a period in excess of the maximum coping period of sixteen hours contemplated by the rule through the passive protection provided bj the spent fuel pool.
111. JUSTIFICATION FOR GRANTING THE EXEMPTION REQUEST The specific requirements for granting exemptions from Part 50 regulations are set forth in 10CFR50.12. Under Section 50.12 (a)(1), the Commission is authorized to grant an exemption upon demonstration that the exemption: (A) is authorized by law; (B) will not present an undue risk to the public health and safQ and (C)is consistent with the common defense and security. Under Section 50.12 (a)(2), special circumstances must exist for the NRC to conrider the exemption request.
Special circumstances include: (A) application of the regulation in the particular circumstances conflicts with other rules or requirements of the Commission, (B) particular circumstances where the application of the regulation would not serve the underlying purpose of the rule or is not necessary te achieve the underlying purpose of the rule, (C) undue hardship or costs that are significantly in excess of those incurred by others similarly situated, (D) the exemption would result in benefit to the public health and safety that compensates for any decrease in safety that may result from the grant of the exemption,(E) the exemption would provide only temporary relief from the applicable regulation and the licensee has made a good faith effort to comply, or (F) there is present any other material circumstance not considered when the regulation was adopted for which it would be in the public interest to grant an exemption. The following justification addresses these requirements and demonstrates that the Commission should grant the requested exemption.
As indicated above, the underlying purpose of 10CFR50.63 is to ensure that nuclear power plants i
can cope with a loss of onsite and offsite AC power for up to sixteen hours depending on the plant design and site characteristics. Maine Yankee has been shut down since December 1996 and is no longer authorized to operate the reactor or place fuel in the reactor vessel. In this condition, Maine Yankee could experience a loss of all AC power for a period in excess of sixteen hours without experiencing any fuel damage. Continued implementation of the commitments made in response to 10CFR50.63 is no longer necessary to achieve the objective of the regulation for Maine Yankee and is not necessary to adequately protect public health and safety. Therefore, requiring Maine Yankee to comply with 10 CFR 50.63 as defined by the original commitments made to the rule is not necessary to achieve the underlying purpose of the rule.
The significant costs involved with maintenance of the equipment and procedures associated with compliance with the commitments made in response to 10 CFR 50.63 outweigh the potential benefits. Because Maine Yankee is a permanently shutdown facility and no longer possesses a license authorizing reactor operation or placement or retention of fuel in the reactor, the limited resources at the site are dedicated to the safe storage of fuel and the preparations for decommissioning of the facility. The costs involved in maintenance of the equipment and procedures complying with the commitments made in resp,nse to 10 CFR 50.63 would result in inefficient use of Maine Yankee resources. Therefore, Ma'ne Yankee's compliance with the commitments made b response to 10 CFR 50.63 would result in undue financial and administrative hardship to Maine Yankee, its owners and their ratepayers.
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The continued implementation of the commitments made under 10CFR50.63 during decommisioning was not considered when the regulation was adopted and continued impementation
,of these requirements during decommissioning would unnecessarily interfere with the process.
During decommissioning, the equipment associated with prior commitments to station blackout must be dismantled, and the procedures associated with that equipment must be canceled. it is not in the public interest to burden the decommissioning process with unnecessary requirements which would detract from the focus of safe fu:1 storage and the safe conduct of the decommissioning process.
Therefore it would be in the public interest to grant the exemption.
IV. CONCLUSION Maine Yankee has concluded that the requested exemption from 10CFR50.63 is justified. It is authorized by law, will not present undue risk to the public health and safety, and is consistent with the common defense and security.
Such an exemption meets the requirements of l
10CFR50.12(a)(2)(ii) in that maintaining a station blackout program in the defueled plant condition is not necessary to achieve the underlying purpose of the rule, and the requirements of 10CFR50.12(a)(2)(iii) in that compliance with the requirements to maintain a station blackout program would result in undue costs for a facility in the decommissioning process. Such an exemption also meets the requirements of 10CFR50.12(a)(2)(vi) in that application of. the requirements during decommissioning was not considered during the original adoption of the rule and it is in the public interest to allow the decommissioning to proceed without being encumbered by unnecessary requirements.
V. ENVIRONMENTALIMPACT Pursuant to the provisions of 10CFR50.12, Maine Yankee is requesting exemption to the requirements of10 CFR 50.63 to maintain equipment and procedures associated with mitigation of a postulated loss of all AC power. The defueled plant condition meets the intent of the tule in that the plant can cope with a loss of all AC power for a period in excess of the maximum period contemplated in the promulgation of the rule without fuel damage. The proposed exemption does -
not affect the type or quantity of radioactive or non-radioactive effluents and does not have a significant impact on the environment.
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