E6-9629. Limerick Generating Station, Unit 2; Notice of Consideration of Issuance of Amendment to Facility Operating License, Proposed No Significant Hazards Consideration Determination, and Opportunity for a Hearing

The U.S. Nuclear Regulatory Commission (the Commission) is considering issuance of an amendment to Facility Operating License No. NPF-85, issued to Exelon Generation Company, LLC, for operation of the Limerick Generating Station, Unit 2, located in Montgomery County, Pennsylvania.

The proposed one-time amendment would revise Technical Specification (TS) Limiting Condition for Operation (LCO) 3.6.1.7 concerning drywell average air temperature. Specifically, the proposed change would add a footnote to the TS limit for drywell average air temperature of 145 degrees Fahrenheit (°F) to allow continued operation of LGS, Unit 2, with drywell average air temperature no greater than 148 °F or the remainder of the current operating cycle (Cycle 9), which is currently scheduled to end in March 2007, or until the next shutdown of sufficient duration to allow for unit cooler fan repairs, whichever comes first.

The exigent amendment request is being made because both fans of the 2D drywell unit cooler are inoperable and out of service, which resulted in an increase in drywell average air temperature from approximately 129 °F to approximately 142 °F. Historically, LGS has experienced an increase in the drywell average air temperature of 2-4 °F during the summer months with normal drywell air cooling system operation. Under the current plant condition, this could result in the potential to exceed the TS limit of 145 °F. Noticing this license amendment request in the Biweekly Federal Register Notice for the standard 30-day public comment period would not expire until July 2006. Therefore, the combination of the increase in the drywell average air temperature during the summer months and the standard regulatory process for noticing license amendment requests could result in an unwarranted plant shutdown.

Before issuance of the proposed license amendment, the Commission will have made findings required by the Atomic Energy Act of 1954, as amended (the Act) and the Commission's regulations.

Pursuant to 10 CFR 50.91(a)(6) for amendments to be granted under exigent circumstances, the NRC staff must determine that the amendment request involves no significant hazards consideration. Under the Commission's regulations in 10 CFR 50.92, this means that operation of the facility in accordance with the proposed amendment would not (1) Involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety. As required by 10 CFR 50.91(a), the licensee has provided its analysis of the issue of no significant hazards consideration, which is presented below:

1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No. The increase in the allowable drywell average air temperature during normal plant operation does not make any physical changes to the plant. It only permits the plant to operate at a higher drywell average air temperature for a limited period of time, and therefore, does not increase the probability of an accident previously evaluated. This increase in the drywell average air temperature has been evaluated to ensure that the change does not adversely affect the ability of the primary containment to perform its safety related function during accident conditions.

The LGS containment design was previously evaluated using an initial average air temperature of 150 °F for the design basis Loss-of-Coolant Accident (LOCA). The results of this evaluation showed that the peak drywell air temperature does not exceed the limit of 340 °F post-accident and that the peak drywell pressure does not exceed the design limit of 55 psig. In addition, the results of this evaluation showed that the peak suppression pool temperature does not exceed the suppression pool structural design limit of 220 °F, and does not exceed the low pressure Emergency Core Cooling System (ECCS) pump net positive suction head (NPSH) limit of 212 °F. The proposed change is also bounded by the current small line break analysis.

Evaluation of components in the drywell has determined that the proposed one-time increase in the drywell average air temperature does not adversely affect the capability to perform their safety function. For components in the drywell, the qualified life was based on operation at a minimum drywell average air temperature of 145 °F. An evaluation of the qualified life of components in the drywell has been performed and has determined that current qualification will not be adversely impacted even if the components are exposed to a temperature of 150 °F for the remainder of the current operating cycle. The increased average air temperature of the drywell atmosphere does not degrade or compromise any coolant boundaries nor does it degrade or compromise any primary containment boundaries from performing their design functions during or following an accident condition. This proposed change does not result in or require any systems or components to be operated outside of their design limits.

This proposed change does not adversely affect mitigating systems, structures or components, and does not adversely affect the initial conditions of any accidents. Redundancy and diversity of mitigating systems are unchanged as a result of this proposed change. This proposed change does not affect onsite or offsite radiological consequences of any accident previously evaluated in the Safety Analysis Report (SAR).

Therefore, this proposed TS change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No. The one-time increase in the drywell average air temperature proposed by this TS change does not change any SSC [structures, systems, and components of the plant. This TS change does not create new operating or failure modes. The normal operating drywell average air temperature is maintained to prevent the peak temperature/pressure of the primary containment from exceeding the design limit, and to ensure that SSCs perform their safety functions before, during and after accident conditions. A previous evaluation has shown that the limits for the drywell and suppression pool design temperatures and pressures are not exceeded by the proposed change.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. Does the proposed change involve a significant reduction in a margin of safety?

Response: No. This proposed change will allow the plant to operate at a higher drywell average air temperature during normal operation for the remainder of the current operating cycle. This higher drywell average air temperature (148 °F) is still below the initial conditions (150 °F) specified in the current short and long-term containment analyses. This change does not create additional heat loads or change the way any of the equipment is operated. A previous evaluation has demonstrated that the drywell and suppression pool design pressures and design temperatures and code requirements are maintained. Therefore, this one-time change to the TS drywell average air temperature limit, to allow the plant to operate no greater than 148 °F for no longer than the remainder of the current operating cycle, does not have any adverse effect on the ability of safety-related SSCs to perform their design functions. The SSCs are designed to function following a LOCA where drywell temperature can peak at 340 °F. For components in the drywell, the qualified life was based on operation at a minimum drywell average air temperature of 145 °F. An evaluation of the qualified life of components in the drywell has been performed and has determined that current qualification will not be adversely impacted even if the components are exposed to a temperature of 150 °F for the remainder of the current operating cycle.

Therefore, this proposed change does not involve a significant reduction in a margin of safety.

The NRC staff has reviewed the licensee's analysis and, based on this review, it appears that the three standards of 10 CFR 50.92(c) are satisfied. Therefore, the NRC staff proposes to determine that the amendment request involves no significant hazards consideration.

The Commission is seeking public comments on this proposed determination. Any comments received within 14 days after the date of publication of this notice will be considered in making any final determination.

Normally, the Commission will not issue the amendment until the expiration of the 14-day notice period. However, should circumstances change during the notice period, such that failure to act in a timely way would result, for example, in derating or shutdown of the facility, the Commission may issue the license amendment before the expiration of the 14-day notice period, provided that its final determination is that the amendment involves no significant hazards consideration. The final determination will consider all public and State comments received. Should the Commission take this action, it will publish in the Federal Register a notice of issuance. The Commission expects that the need to take this action will occur very infrequently.

Written comments may be submitted by mail to the Chief, Rules and Directives Branch, Division of Administrative Services, Office of Administration, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, and should cite the publication date and page number of this Federal Register notice. Written comments may also be delivered to Room 6D59, Two White Flint North, 11545 Rockville Pike, Rockville, Maryland, from 7:30 a.m. to 4:15 p.m. Federal workdays. Documents may be examined, and/or copied for a fee, at the NRC's Public Document Room, located at One White Flint North, 11555 Rockville Pike (first floor), Rockville, Maryland.

The filing of requests for hearing and petitions for leave to intervene is discussed below.

Within 60 days after the date of publication of this notice, the licensee may file a request for a hearing with respect to issuance of the amendment to the subject facility operating license and any person whose interest may be affected by this proceeding and who wishes to participate as a party in the proceeding must file a written request for a hearing and a petition for leave to intervene. Requests for a hearing and a petition for leave to intervene shall be filed in accordance with the Commission's “Rules of Practice for Domestic Licensing Proceedings” in 10 CFR part 2. Interested persons should consult a current copy of 10 CFR 2.309, which is available at the Commission's PDR, located at One White Flint North, Public File Area 01F21, 11555 Rockville Pike (first floor), Rockville, Maryland. Publicly available records will be accessible from the Agencywide Documents Access and Management System's (ADAMS) Public Electronic Reading Room on the Internet at the NRC Web site, http://www.nrc.gov/​reading-rm/​doc-collections/​cfr/​. If a request for a hearing or petition for leave to intervene is filed by the above date, the Commission or a presiding officer designated by the Commission or by the Chief Administrative Judge of the Atomic Safety and Licensing Board Panel, will rule on the request and/or petition; and the Secretary or the Chief Administrative Judge of the Atomic Safety and Licensing Board will issue a notice of a hearing or an appropriate order.

As required by 10 CFR 2.309, a petition for leave to intervene shall set forth with particularity the interest of the petitioner in the proceeding, and how that interest may be affected by the results of the proceeding. The petition should specifically explain the reasons why intervention should be permitted with particular reference to the following general requirements: (1) The name, address and telephone number of the requestor or petitioner; (2) the nature of the requestor's/petitioner's right under the Act to be made a party to the proceeding; (3) the nature and extent of the requestor's/petitioner's property, financial, or other interest in the proceeding; and (4) the possible effect of any decision or order which may be entered in the proceeding on the requestor's/petitioner's interest. The petition must also identify the specific contentions which the petitioner/requestor seeks to have litigated at the proceeding.

Each contention must consist of a specific statement of the issue of law or fact to be raised or controverted. In addition, the petitioner/requestor shall provide a brief explanation of the bases for the contention and a concise statement of the alleged facts or expert opinion which support the contention and on which the petitioner intends to rely in proving the contention at the hearing. The petitioner/requestor must also provide references to those specific sources and documents of which the petitioner/requestor is aware and on which the petitioner/requestor intends to rely to establish those facts or expert opinion. The petitioner/requestor must provide sufficient information to show that a genuine dispute exists with the applicant on a material issue of law or fact. Contentions shall be limited to matters within the scope of the amendment under consideration. The contention must be one which, if proven, would entitle the petitioner/requestor to relief. A petitioner/requestor who fails to satisfy these requirements with respect to at least one contention will not be permitted to participate as a party.

Those permitted to intervene become parties to the proceeding, subject to any limitations in the order granting leave to intervene, and have the opportunity to participate fully in the conduct of the hearing.

If a hearing is requested, the Commission will make a final determination on the issue of no significant hazards consideration. The final determination will serve to decide when the hearing is held. If the final determination is that the amendment request involves no significant hazards consideration, the Commission may issue the amendment and make it immediately effective, notwithstanding the request for a hearing. Any hearing held would take place after issuance of the amendment. If the final determination is that the amendment request involves a significant hazards consideration, any hearing held would take place before the issuance of any amendment.

Nontimely requests and/or petitions and contentions will not be entertained absent a determination by the Commission or the presiding officer of the Atomic Safety and Licensing Board that the petition, request and/or the contentions should be granted based on a balancing of the factors specified in 10 CFR 2.309(c)(1)(I)-(viii).

A request for a hearing or a petition for leave to intervene must be filed by: (1) First class mail addressed to the Office of the Secretary of the Commission, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, Attention: Rulemaking and Adjudications Staff; (2) courier, express mail, and expedited delivery services: Office of the Secretary, Sixteenth Floor, One White Flint North, 11555 Rockville Pike, Rockville, Maryland, 20852, Attention: Rulemaking and Adjudications Staff; (3) E-mail addressed to the Office of the Secretary, U.S. Nuclear Regulatory Commission, [e-mail]; or (4) facsimile transmission addressed to the Office of the Secretary, U.S. Nuclear Regulatory Commission, Washington, DC, Attention: Rulemakings and Adjudications Staff at [phone], verification number is [phone]. A copy of the request for hearing and petition for leave to intervene should also be sent to the Office of the General Counsel, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, and it is requested that copies be transmitted either by means of facsimile transmission to 301-415-3725 or by e-mail to [e-mail]. A copy of the request for hearing and petition for leave to intervene should also be sent to Mr. Brad Fewell, Assistant General Counsel, Exelon Generation Company, LLC, 200 Exelon Way, Kennett Square, PA 19348, attorney for the licensee.

For further details with respect to this action, see the application for amendment dated June 9, 2006, which is available for public inspection at the Commission's Public Document Room (PDR), located at One White Flint North, Public File Area O1 F21, 11555 Rockville Pike (first floor), Rockville, Maryland. Publicly available records will be accessible electronically from the Agencywide Documents Access and Management System's (ADAMS) Public Electronic Reading Room on the Internet at the NRC Web site http://www.nrc.gov/​reading-rm.html. Persons who do not have access to ADAMS or who encounter problems in accessing the documents located in ADAMS, should contact the NRC PDR Reference staff by telephone at 1-800-397-4209, 301-415-4737, or by e-mail to [e-mail].

Dated at Rockville, Maryland, this 14th day of June 2006.

For the Nuclear Regulatory Commission.

Richard V. Guzman,

Project Manager, Plant Licensing Branch I-2, Division of Operating Reactor Licensing, Office of Nuclear Reactor Regulation.