ML082610224
| ML082610224 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 09/11/2008 |
| From: | Minahan S Nebraska Public Power District (NPPD) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| GL-08-001, NLS2008074 | |
| Download: ML082610224 (5) | |
Text
N Nebraska Public Power District "Always there when you need us" 50.54(f)
NLS2008074 September 11, 2008 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555-0001
Subject:
Request for Extension to Generic Letter 2008-01 Cooper Nuclear Station, Docket No. 50-298, DPR-46
Reference:
NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems,"
dated January 11, 2008
Dear Sir or Madam:
The purpose of this letter is for Nebraska Public Power District (NPPD) to request an extension from the Nuclear Regulatory Commission (NRC) regarding Generic Letter (GL) 2008-01. Specifically, NPPD will be unable to complete all of the necessary walkdowns and evaluations associated with the resolution of GL 2008-01 at Cooper Nuclear Station (CNS) prior to the GL response due date of October 11, 2008. These walkdowns and evaluations are associated with piping and components located within CNS primary containment. NPPD will complete the necessary walkdowns within CNS primary containment during the next outage of sufficient duration or no later than the conclusion of Refueling Outage (RE) 25, tentatively scheduled to commence Fall 2009. A follow-up submittal will be provided to the NRC no later than 90 days following an outage of sufficient duration or the completion of RE-25.
Background Information GL 2008-01, issued January 11, 2008, requested, in part, that power reactor licensees take the appropriate actions within nine months of the issuance of the GL to provide the information requested (nine-month response), pursuant to 10 CFR 50.54(f). If the licensee's actions could not be performed in that period, then the licensee was required to provide a response within three months of the date of the GL, describing the alternative course of action it proposes to take, including the basis for the acceptability of the proposed alternative course of action.
COOPER NUCLEAR STATION P0. Box 98 / Brownville, NE 68321-0098 iJ.
2 Telephone: (402) 825-3817 / Fax: (402) 825-5211 www.nppd.com
NLS2008074 Page 2 of 4 NPPD evaluated the actions necessary to satisfy the nine-month response during the three-month response period and determined that all the actions within its control, including completion of necessary walkdowns, would be completed within the nine-month period. As such, a three-month response was not submitted to the NRC. This decision was based, in part, on an internal determination that walkdowns within primary containment were not warranted given the inherent design of the piping and components, and confidence in the as-built configuration in relation to the as-designed configuration.
Walkdowns were not viewed at that time to be a requirement of the GL provided that other means existed to document possible gas accumulation locations and evaluate its effects.
The decision not to perform walkdowns within primary containment was made just prior to RE-24, which commenced April 12, 2008, and concluded May 17, 2008. Since that time, the scope and level of rigor for industry walkdowns expected to support the nine-month response have evolved. Several Boiling Water Reactor (BWR-4) licensees proceeded with, or have planned, walkdowns within their primary containments during the nine-month period. In order to be consistent with the current industry expectations, NPPD has determined that walkdowns within the CNS primary containment would be prudent to support the GL response. However, these walkdowns are not possible without a plant shutdown of sufficient duration to de-inert primary containment, erect scaffolding, remove piping insulation, and properly plan to minimize additional dose.
Piping and Components not Accessible Ahead of the Nine-Month Response The following systems contain piping and components, within the scope of GL 2008-01 which can not be accessed until RE-25 or outage of sufficient duration:
Note:
Walkdowns of High Pressure Coolant Injection (HPCI) piping were completed during the as-building process for installation of high point vents on HPCI piping within the steam tunnel.
Core Spray (CS) discharge piping and components - From the containment penetration to the reactor pressure vessel.
Residual Heat Removal piping and components (RHR, Shutdown Cooling, and Low Pressure Coolant Injection (LPCI) modes) - From the containment penetration to the reactor pressure vessel.
Proposed Alternative Course of Action NPPD will complete the necessary walkdowns within CNS primary containment during the next outage of sufficient duration or no later than the conclusion of RE-25, tentatively scheduled to commence Fall 2009. A follow-up submittal to the nine-month response will
NLS2008074 Page 3 of 4 be provided to the NRC no later than 90 days following an outage of sufficient duration or the completion of RE-25.
NPPD plans to complete the necessary walkdowns outside of primary containment in time to support the nine-month response due October 11, 2008.
Basis for Acceptability NPPD is confident the portions of the GL subject systems (CS, and RHR) within primary containment can fulfill their required design functions based on the following reasons:
(1)
NPPD is confident that the as-built configuration of the subject piping and components is correctly reflected in the applicable drawings. Reviews of the drawings, applicable to the systems within primary containment and subject to the GL, performed to-date have not revealed vulnerabilities related to the GL.
(2)
Past and current operating experience and testing performed since plant licensing have demonstrated that the subject systems can support their design functions.
(3)
High point vents are installed within primary containment on the subject systems piping. These vents are utilized for the removal of gas during fill and vent activities.
(4)
CS system has experienced an injection to the reactor vessel in the past. There was no report of water hammer during this event.
(5)
RHR system is lined up to Shutdown Cooling mode every outage. This lineup utilizes the same injection lines used for LPCI mode within primary containment.
There have been no indications of water hammer events upon start of these systems.
For these reasons, NPPD concludes that completing performance of detailed walkdowns on a portion of the systems that require an outage of sufficient duration and subsequent evaluations outside the nine-month period is an acceptable alternative course of action.
By copy of this letter, the appropriate State of Nebraska official is notified. Copies to the NRC Region IV office and the CNS Senior Resident Inspector are also being provided in accordance with 10 CFR 50.4(b)(1).
If you have any questions regarding this matter, please call David Van Der Kamp, CNS Licensing Manager, at (402) 825-2904.
NLS2008074 Page 4 of 4 I declare under penalty of perjury that the foregoing is true and correct.
Executed On (Date)
Sincerely, Stewart B. Minahan Vice President - Nuclear and Chief Nuclear Officer
/dm cc:
Regional Administrator USNRC - Region IV Cooper Project Manager USNRC - NRR Project Directorate IV-l Senior Resident Inspector USNRC - CNS Nebraska Health and Human Services Department of Regulation and Licensure CNS Records NPG Distribution
ATTACHMENT 3 LIST OF REGULATORY COMMITMENTS@
ATTACHMENT 3 LIST OF REGULATORY COMMITMENTS© Correspondence Number: NLS2008074 The following table identifies those actions committed to by Nebraska Public Power District (NPPD) in this document. Any other actions discussed in the submittal represent intended or planned actions by NPPD. They are described for information only and are not regulatory commitments. Please notify the Licensing Manager at Cooper Nuclear Station of any questions regarding this document or any associated regulatory commitments.
COMMITMENT COMMITTED DATE COMMITMENT NUMBER OR OUTAGE NPPD will complete the necessary walkdowns within CNS primary containment during the next At completion of outage outage of sufficient duration or no later than the NLS2008074-01 of sufficient duration or conclusion of RE-25, tentatively scheduled to completion of RE-25 commence Fall 2009.
90 days following an A follow-up submittal to the nine-month outage of sufficient duration or 90 days response will be provided to the NRC no later NLS2008074-02 following completion of than 90 days following an outage of sufficient R0f g
e duration or the completion of RE-25.
RE-25 PROCEDURE 0.42 REVISION 22 PAGE 18 OF 26