The U.S. Nuclear Regulatory Commission (the Commission) is considering issuance of an amendment to Facility Operating License No. NPF-21, issued to Energy Northwest (the licensee), for operation of the Columbia Generating Station located in Benton County, Washington.
The proposed amendment would revise Technical Specification (TS) 126.96.36.199, “Suppression Chamber-to-Drywell Vacuum Breakers,” to allow a one-time extension to the current closure verification surveillance requirement (SR) for one of two Start Printed Page 6607redundant disks in one of nine vacuum breakers until reliable position indication can be restored in the main control room during the next refueling outage (R-18). Verification of closure of each vacuum breaker disk is currently required every 14 days by SR 188.8.131.52.1. The licensee requested that the proposed change be considered on an exigent basis.
The licensee stated that during the January 6, 2007, functional test of vacuum breaker CVB-V-1JK, one of the redundant disks in the vacuum breaker assembly did not meet the procedurally defined acceptance criteria for open or close due to an issue with position indication limit switches. This problem has resulted in unreliable position indication for closure of the rear disk of the vacuum breaker and requires an alternate method of closure verification be employed (i.e., a differential pressure test). Consistent with SR 184.108.40.206.1, this test must be performed every 14 days. However, performance of the alternate test creates an unnecessary increase in plant risk relative to other compensatory options.
The proposed one-time change to TS 220.127.116.11 would revise SR 18.104.22.168.1 by adding a note to provide an extension to the SR for the rear disk of vacuum breaker CVB-V-1JK. This extension would remain in effect until the end of R-18, currently scheduled to begin on May 12, 2007.
On January 6, 2007, during a functional test of vacuum breaker CVB-V-1JK, the rear disk of the vacuum breaker did not meet the procedurally defined acceptance criteria for open or close due to an issue with the position indication limit switches. When CVB-V-1JK was cycled from the control room, the close position indication did not extinguish and prevented the open position indication from illuminating. The separate full open indication did illuminate, indicating that the rear disk opened as expected; however, the closure of the disk could not be confirmed using normal position indication.
With unreliable position indication in the main control room for the rear disk of vacuum breaker CVB-1JK, the alternate method of closure verification using the differential pressure test is required. This test, as described in the TS Bases, involves establishing a differential pressure between the drywell and suppression chamber equal to, or in excess of, 0.5 pounds per square inch differential (psid) to verify that the disk being tested can maintain that differential for 60 minutes. Current test procedures specify that a differential pressure of 0.7 to 0.75 psid be established between the drywell and suppression chamber. This value provides margin to accommodate minor internal drywell temperature changes during the testing. Maintaining a differential pressure between the drywell and suppression chamber is a positive indication that the vacuum breaker disk being tested is closed. This test was performed on the rear disk of vacuum breaker CVB-V-1JK on January 8, 2007, and again on January 22, 2007, and confirmed that the disk was seated. The degraded limit switches and associated circuitry are located in the inerted wetwell and cannot be accessed to restore normal position indication in the control room for the rear disk of vacuum breaker CVB-V-1JK while at power. Therefore, continued compliance with SR 22.214.171.124.1 would require that this pressure test be performed every 14 days.
The licensee stated that when performing the vacuum breaker closure differential pressure test, drywell pressure is increased from near atmospheric conditions to approximately 45 percent of the Drywell Pressure—High scram setpoint of 1.68 pounds per square inch gauge. Frequent differential pressure testing places the plant in a condition with degraded margin for a reactor scram. This increases the risk of an inadvertent reactor scram from a minor drywell pressure transient which may have been managed by the operator if it occurred at a normal drywell pressure and can unduly challenge plant safety systems and personnel. Furthermore, when performing the differential pressure test to verify continued closure of the rear disk of vacuum breaker CVB-V-1JK, the front disk is required to be open for at least 60 minutes while the test is being performed which degrades the capability of the vacuum breaker assembly to prevent bypass leakage when required. As previously discussed, TS 126.96.36.199 recognizes this increase in plant risk by drawing a distinction between an actual communication path and a potential communication path in the derivation of entry conditions and required actions.
The licensee concluded that a more appropriate method to maintain public health and safety is to ensure that both disks of vacuum breaker CVB-V-1JK continue to maintain their current closed position without a change of state. Operating in this configuration, both the front and rear disks of vacuum breaker CVB-V-1JK would conservatively not be credited to perform the open safety function and would be declared inoperable for opening. Both disks are currently closed and have been verified as such using the normal position indication in the control room for the front disk and by the differential pressure test for the rear disk. This configuration is currently allowed by TS 188.8.131.52, since only seven of nine vacuum breakers are required to be operable for opening while in Modes 1, 2, and 3. In addition, with vacuum breaker CVB-V-1JK declared inoperable for the open function, SR 184.108.40.206.2 would not be required to be performed and the breaker disks would not need to be cycled.
Continued operation in this manner until the end of R-18 would ensure that plant risk is minimized but also requires an extension from the current 14-day interval of SR 220.127.116.11.1. The proposed change is necessary because continued performance of SR 18.104.22.168.1 for the rear disk of CVB-V-1JK results in putting the plant in a condition that unduly increases the risk of an inadvertent reactor scram challenging both plant systems and personnel. Failure to perform the differential pressure test required by SR 22.214.171.124.1 would result in a failed verification of the current closed state of these vacuum breakers. TS 126.96.36.199 would then require placing the reactor in Mode 3 within the next 84 hours and Mode 4 in the following 24 hours and would also challenge plant system and personnel.
The licensee states that it will continue to verify that the front disk of CVB-V-1JK and both disks of the other 8 vacuum breakers are closed every 14 days as required by SR 188.8.131.52.1. If reasonable evidence is discovered to conclude that the rear disk of vacuum breaker CVB-V-1JK may no longer be in a closed position, the licensee states that it will take compensatory measures to verify that this disk is closed within 72 hours or declare the disk not closed and enter the appropriate action statement. In the proposed note, evidence that the rear disk may no longer be in a closed position is defined as evidence that the front disk has opened or that the rear disk has experienced a differential pressure in the direction that could cause the disk to open.
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 Start Printed Page 6608accordance 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 amendment involve a significant increase in the probability or consequences of an accident previously evaluated?
Proper functioning of the suppression chamber-to-drywell vacuum breakers is required for accident mitigation. Failure of the vacuum breakers is not assumed as an accident initiator for any accident previously evaluated. Therefore, any potential failure of a vacuum breaker to perform when necessary will not affect the probability of an accident previously evaluated.
During a LOCA [loss-of-coolant accident], the vacuum breakers are assumed to initially be closed to limit drywell-to-suppression chamber bypass leakage and must be capable of re-closing following a suppression pool swell event. The vacuum breakers open to prevent an excessive vacuum in the drywell. The proposed change will not affect the capability of the required vacuum breakers to perform their open and close safety functions since the change only affects position verification and high confidence is assured that the disk remains closed. Therefore, the proposed changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.
2. Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?
The suppression chamber-to-drywell vacuum breakers are used to mitigate the potential consequences of an accident. The proposed change does not affect the capability of required vacuum breakers to perform their open and closed safety functions. Thus, the initial conditions assumed in the accident analysis are not affected. The proposed amendment does not involve a change to plant design and does not involve any new modes of operation or testing methods. Accordingly, the required vacuum breakers will continue to perform their accident mitigation safety functions as previously evaluated. Therefore, the proposed changes do not create the possibility of a new or different kind of accident from any accident previously evaluated.
3. Does the proposed amendment involve a significant reduction in a margin of safety?
The extension of the closure verification surveillance interval for one of the two disks in a vacuum breaker for approximately 4 months is not risk significant as all required safety functions will continue to be performed. The vacuum breakers are not modified by the proposed amendment. The accident analysis assumptions for the closed safety functions of the vacuum breakers are satisfied when at least one of the disks in each of the nine vacuum breaker lines are fully closed and capable of re-closing following a suppression pool swell. The additional disk in each line satisfies the single failure criterion. The open safety function of the vacuum breakers is satisfied when 6 of the 9 vacuum breaker assemblies open during a DBA [design basis accident]. The other vacuum breakers satisfy the single failure criterion and provide additional defense-in-depth. Since all of the vacuum breakers are considered to perform their close safety function and 8 of 9 would be available to perform their open safety function, the proposed change will 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, Rulemaking, Directives and Editing 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, Public File Area O1 F21, 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 and Issuance of Orders” 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 O1 F21, 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 Start Printed Page 6609effect 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, HEARINGDOCKET@NRC.GOV; or (4) facsimile transmission addressed to the Office of the Secretary, U.S. Nuclear Regulatory Commission, Washington, DC, Attention: Rulemakings and Adjudications Staff at (301) 415-1101, verification number is (301) 415-1966. 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 OGCMailCenter@nrc.gov. A copy of the request for hearing and petition for leave to intervene should also be sent to William A. Horin, Esq., Winston & Strawn, 1700 K Street, NW., Washington, DC 20006-3817, attorney for the licensee.
For further details with respect to this action, see the application for amendment dated February 2, 2007, 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, or 301-415-4737, or by e-mail to firstname.lastname@example.org.Start Signature
Dated at Rockville, Maryland, this 6th day of February 2007.
For the Nuclear Regulatory Commission.
Carl F. Lyon,
Project Manager, Plant Licensing Branch IV, Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation.
[FR Doc. E7-2374 Filed 2-9-07; 8:45 am]
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