ML082590368
| ML082590368 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 09/17/2008 |
| From: | Richard Guzman Plant Licensing Branch 1 |
| To: | Polson K Nine Mile Point |
| Guzman R, NRR/DORL, 415-1030 | |
| References | |
| GL-08-001, TAC MD7848 | |
| Download: ML082590368 (8) | |
Text
September 17, 2008 Mr. Keith J. Polson Vice President Nine Mile Point Nine Mile Point Nuclear Station, LLC P.O. Box 63 Lycoming, NY 13093
SUBJECT:
NINE MILE POINT NUCLEAR STATION, UNIT NO. 1 - RE: GENERIC LETTER 2008-01, MANAGING GAS ACCUMULATION IN EMERGENCY CORE COOLING, DECAY HEAT REMOVAL, AND CONTAINMENT SPRAY SYSTEMS, PROPOSED ALTERNATIVE COURSE OF ACTION (TAC NO. MD7848)
Dear Mr. Polson:
On January 11, 2008, the Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2008-01, Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems (Agencywide Documents Access and Management System (ADAMS) Accession No. ML072910759). The GL requested licensees to submit information to demonstrate that the emergency core cooling, decay heat removal, and containment spray systems (hereinafter referred to as the subject systems) are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, operational, and testing control measures are in place for maintaining this compliance.
In accordance with Section 50.54(f) of Title 10 of the Code of Federal Regulations (10 CFR),
GL 2008-01 required that each licensee submit the requested information within 9 months (hereinafter referred to as the 9-month submittal) of the date of the GL. The GL also stated that if a licensee cannot meet the requested 9-month response date, the licensee is required to provide a response within 3 months (hereinafter referred to as the 3-month submittal) 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.
By letter dated April 10, 2008, Nine Mile Point Nuclear Station, LLC (the licensee), submitted a 3-month response to GL 2008-01 for Nine Mile Point Nuclear Station, Unit No. 1 (NMP1). The NRC staffs assessment of the response for NMP1 is contained in the enclosure to this letter.
The NRC staff reviewed the licensees proposed alternative course of action and the associated basis for acceptance and concluded that for NMP1, the licensees reasons and basis for acceptability for why walkdowns of some piping segments of the GL subject systems would not be completed by October 11, 2008, is acceptable. However, the NRC staff requests that the licensee submit a 3-month supplemental response for NMP1, to revise its proposed alternative course of action related to its 9-month initial response and its 9-month supplemental (post-outage) response as described in the enclosure.
K. J. Polson If you have any questions, please contact me at (301) 415-1030.
Sincerely,
/RA/
Richard V. Guzman, Senior Project Manager Plant Licensing Branch I-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-220
Enclosure:
As stated cc w/encl: See next page
ML082590368 NRR-106 OFFICE LPLI-1/PM LPLI-1/LA PGCB/BC DSS/DD LPLI-1/BC NAME RGuzman MOBrien for SLittle MMurphy JWermeil MKowal DATE 9/15/08 9/17/08 9/16/08 9/15/08 9/17/08
Nine Mile Point Nuclear Station, Unit No. 1 cc:
Mr. Michael J. Wallace, Vice-Chairman Constellation Energy Nuclear Group, LLC 100 Constellation Way, Suite 1800P Baltimore, MD 21202 Mr. Henry B. Barron, President, CEO &
Chief Nuclear Officer Constellation Energy Nuclear Group, LLC 100 Constellation Way, Suite 200C Baltimore, MD 21202 Mr. Terry F. Syrell Director, Licensing Nine Mile Point Nuclear Station P.O. Box 63 Lycoming, NY 13093 Regional Administrator, Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 126 Lycoming, NY 13093 Supervisor Town of Scriba Route 8, Box 382 Oswego, NY 13126 Charles Donaldson, Esquire Assistant Attorney General New York Department of Law 120 Broadway New York, NY 10271 Mr. Paul D. Eddy New York State Department of Public Service 3 Empire State Plaza, 10th Floor Albany, NY 12223 Mark J. Wetterhahn, Esquire Winston & Strawn 1700 K Street, NW Washington, DC 20006 Carey W. Fleming, Esquire Sr. Counsel - Nuclear Generation Constellation Energy Nuclear Group, LLC 750 East Pratt Street, 17th Floor Baltimore, MD 21202 Mr. John P. Spath New York State Energy, Research, and Development Authority 17 Columbia Circle Albany, NY 12203-6399 Mr. Paul Tonko President and CEO New York State Energy, Research, and Development Authority 17 Columbia Circle Albany, NY 12203-6399 Mr. Gary L. Detter Manager - Nuclear Safety and Security Constellation Energy Nuclear Group, LLC 100 Constellation Way, Suite 200C Baltimore, MD 21202
Enclosure ASSESSMENT OF 3-MONTH RESPONSE TO GENERIC LETTER 2008-01 NINE MILE POINT NUCLEAR STATION, LLC (NMPNS)
NINE MILE POINT NUCLEAR STATION, UNIT NO. 1 DOCKET NO. 50-220
1.0 BACKGROUND
On January 11, 2008, the Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2008-01, Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems (Agencywide Documents Access and Management System (ADAMS) Accession No. ML072910759). The GL requested licensees to submit information to demonstrate that the emergency core cooling, decay heat removal, and containment spray systems (hereinafter referred to as the subject systems) are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, operational, and testing control measures are in place for maintaining this compliance.
Specifically, the GL requested licensees to provide: (1) a description of the results of evaluations that were performed in response to the GL; (2) a description of all corrective actions that the licensee determined were necessary; and (3) a statement regarding which corrective actions were completed, the schedule for completing the remaining corrective actions, and the basis for that schedule.
In accordance with Section 50.54(f) of Title 10 of the Code of Federal Regulations (10 CFR),
GL 2008-01 required that each licensee submit the requested information within 9 months (hereinafter referred to as the 9-month submittal) of the date of the GL. The GL also stated that if a licensee cannot meet the requested 9-month response date, the licensee is required to provide a response within 3 months (hereinafter referred to as the 3-month submittal) 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.
2.0 LICENSEES PROPOSED ALTERNATIVE COURSE OF ACTION By letter dated April 10, 2008, Nine Mile Point Nuclear Station, LLC (the licensee), submitted a 3-month response to GL 2008-01 for Nine Mile Point Nuclear Station, Unit No. 1 (NMP1). The licensee stated that they cannot meet the requested 9-month schedule for submitting the requested information because walkdowns of the GL subject systems of NMP1, cannot be completed because portions of the GL subject systems are inaccessible during power operation.
The inaccessible GL subject systems are shutdown cooling and core spray. These sections of piping are inaccessible for the following reasons: (1) the need to enter the drywell that is subject to high radiation atmospheres or an inerted drywell atmosphere (less than 4% oxygen content); and (2) the need to erect scaffolding.
The licensee also stated that it would complete as much of the requested GL actions within the requested 9-month period as is practical, based upon accessibility of the subject systems. As an alternative course of action, the licensee plans to complete walkdowns of those areas only accessible during the next refueling outage for NMP1 scheduled for early 2009. The licensees letter dated April 10, 2008, listed the following commitments:
- 1. Perform and complete required plant walkdowns and inspections associated with NRC GL 2008-01 that cannot be completed with the plant online for NMP Unit 1 before completion of its spring 2009 refueling outage.
- 2. Submit written response to the NRC informing them of the activities performed consistent with the requested actions and information required by GL 2008-01 within 6 months after the completion of the NMP1 spring 2009 refueling outage.
The licensee stated that the alternative course of action is acceptable based on the following:
- 1. NMP 1, being a boiling-water reactor, does not rely upon nitrogen or air-charged accumulators as part of the design of the piping systems for the shutdown cooling or core spray systems. Thus, there are limited scenarios where significant gas entrainment is possible, particularly in the suction piping of the pumps for the systems requiring inspection.
- 2. The core spray system is routinely tested in accordance with technical specifications and the in-service testing program, and no significant issues with accumulated gas have been identified.
- 3. The potential to form vortices and entrain air at the suction pipe inlets and their effect on the core spray system pump performance has been evaluated. Calculations verify that air will not be ingested into the core spray strainers from the water surface of the suppression chamber (torus). In addition, the suction piping for the core spray pumps exits the torus and has no other high points (by design) from that point to the actual pump inlet.
- 4. On the discharge side, the core spray system has a keep-fill system and high point vents.
- 5. The shutdown cooling system operating procedures require venting when placing the system in service, including venting of the shutdown cooling pump casing. The shutdown cooling piping is maintained full of water at all times, thus the likelihood of water hammer effects are significantly decreased.
Based on the above considerations, the licensee stated that it remains confident that the NMP1 core spray and shutdown cooling systems can fulfill their required functions based upon almost 40 years of operating experience, including system walkdowns and detailed evaluations. As such, the licensee concluded that completing performance of the detailed walkdowns of a portion of piping sections outside of the requested 9-month timeframe is an acceptable alternative course of action.
3.0 NRC STAFFS ASSESSMENT The NRC staff finds that for NMP1, the licensees reasons and basis for acceptability for why walkdowns of some piping segments of the GL subject systems would not be completed by October 11, 2008, is acceptable based on the above-described operating experience, current designs, testing procedures, and operating procedures associated with managing gas accumulation. However, the NRC staff requests that the licensee submit a 3-month supplemental response for NMP1, to revise its proposed alternative course of action related to its 9-month initial and supplemental response as described below.
The NRC staff notes that in its 3-month submittal dated April 10, 2008, the licensee stated that it would complete as much of the requested GL actions within the requested 9-month period as is practical, based upon accessibility of the subject systems. The licensee did not state that it would submit the GL requested information for the accessible portions of the subject systems to the NRC by October 11, 2008. The NRC staff also noted that the licensee committed to submit a written response within 6 months after completion of the NMP1 spring 2009 refueling outage instead of 90 days following this outage.
The NRC staff requests that the licensee submit a 3-month supplemental response for NMP1 to revise its proposed alternative course of action related to its 9-month initial and supplemental response. The NRC staff requests that the licensee submit the information requested in the GL as follows:
(1) 9-Month Initial Submittal - For the portions of the subject systems that are accessible prior to the NMP1 spring 2009 refueling outage, provide all GL-requested information to the NRC by October 11, 2008.
(2) 9-Month Supplemental (Post-Outage) Submittal - Except for the long-term items described below, provide all remaining GL-requested information for the subject systems to the NRC within 90 days following startup from the spring 2009 refueling outage at NMP1.
For each of these two submittals (the 9-month initial and supplemental submittals), and consistent with the information requested in the GL, the licensees should provide:
(1) a description of the results of evaluations that were performed in response to the GL; (2) a description of all corrective actions that the licensee determined were necessary; and (3) a statement regarding which corrective actions were completed, the schedule for completing the remaining corrective actions, and the basis for that schedule.
The NRC staff noted that the licensees submittal dated April 10, 2008, did not mention other potential long-term actions that are identified in the GL. For instance, the industry is assessing whether it is necessary to perform pump testing to determine the allowable limits on ingested gas volume in pump suctions, as well as the need to develop an analysis capability to adequately predict void movement (entrapped gas) from piping on the suction side of the pumps into the pumps. It is unlikely this industry effort will be complete for the 9-month initial or supplemental submittals. Further, technical specification changes may be necessary to reflect the improved understanding achieved during response to the GL, but these cannot be fully developed for the 9-month initial or supplemental submittals. A Technical Specifications Task Force traveler may provide a generic example that can be adopted by licensees. The NRC staff requests that the licensee address in its 9-month submittal how it plans to track such long-term actions (e.g., Corrective Action Program and/or commitment tracking). The NRC plans to perform follow-up inspections of licensees responses to GL 2008-01 at all plants using a Temporary Instruction inspection procedure.