ML20212K860
| ML20212K860 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 10/06/1999 |
| From: | Adensam E NRC (Affiliation Not Assigned) |
| To: | Norway R AFFILIATION NOT ASSIGNED |
| References | |
| 2.206, 50-220-97-04, 50-410-97-04, NUDOCS 9910070068 | |
| Download: ML20212K860 (7) | |
Text
.
!scre UNITED STATES p*
(, 4 E NUCLEAR REGULATORY COMMISSION k
E' WASHINGTON, D.C. 20555-0001 s
/
October 6, 1999 Mr. Robert Norway
Dear Mr. Norway:
In a letter dated June 9,1999 Mr. Roy P. Zimmerman acknowledged receipt of your Petition requesting actions under 10 CFR 2.206 that you sent to Dr. William Travers, Executive Director for Operations, U.S. Nuclear Regulatory Commission (NRC), on April 5,1999. One of the issues raised in the Petition regards a technical concern about the Residual Heat Removal (RHR) Alternate Shutdown Cooling (ASC or ASD) modes of operation at Nine Mile Point Nuclear Station, Unit 2 (NMP2). Mr. Zimmerman stated in his letter that the NRC staff would address this technical issue separately from the other issues in the Petition. Accordingly, this letter addresses your technical concern regarding the RHR/ASC issue.
In the Petition, you identify a technical concern in which you question
..the credibility of the NMP2 Safety Evaluation 94-091 andits conclusion that the attemate ASC did not need to meet the requirements of RG [ Regulatory Guide]
1.139 to perform its intended safety function within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> (even though it was a licensed commitment in the NMP2 UFSAR [ Updated Final Safety Analysis Report; a.k.a., USAR] solely on the basis that this RG requirement is listed as a
'should'and not a 'shall', and that they[ Niagara Mohawk Power Corporation] had an (54 Hr) method available.
You also question the credibility of the related findings in the corresponding NRC Inspection Report (IR) 50-220/97-04 and 50-410/97-04, page 8.
On the basis of this concern, you request in the Petition that the NRC
... publicly post NMPC's NMP2 RHR ASD Safety Evaluation 96-091 (along with its associated sections from IR 50-410/97-04, under SELECTED REPORTS on the internet) to make it available for public comment OR require NMPC 60 days to re-perform this safety evaluation in order to thoroughly review and document this issue to the NMP2 Licensing basis. Ifit is NMPC's intention not-to-have any RHR alternate shutdown cooling methods available to meet the 36 hour4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> requirement specifiedin RG 1.139 (i.e. not to in~' this !JSAP! Reg. Guide Licensing Basis Requirement), then NMPC shall follow the aooropriate reoulatorv orocess to take an exception to this Reg. Guide licensing requirement, L
provide adequate engineering and safety evaluations (to demonstrate that all previously analyzed accidents limits are not exceeded) and Modify their License ffN accordingly.
P The staff has evaluated your technical concern and mquests. The staff's evaluation team
~ included a senior member of our Reactor Systems Branch, located at NRC Headquarters, who 9910070060 991006 PDR ADOCK 05000220 0
i.
f R. Norway is very knowledgeable of the history and content of draft RG 1.139, related guidance in the Standard Review Plan (SRP, NUREG-0800), and the NMP2 RHR/ASC system design. The evaluation team did not include any members directly involved with the prior inspection findings in IR 50-410/97-04, but the team did reexamino many of the documents upon which those inspection findings were based. Further background and the results of this evaluation are presented in the following sections.
BACKGROUND Each RG issued by the NRC, including draft RG 1.139 when issued for comment, includes the following statement:
Regulatory Guides are issued to describe and make available to the public methods acceptable to the NRC staff ofimplementing specificparts of the Commission's regulations, to delineate techniques used by the staffin evaluating specific problems or postulated accidents, or to provide guidance to applicants.
Regulatory Guides are not substitutes for regulations, and compliance with them is not required. Methods and solutions different from those set out in the guides willbe acceptable if they provide a basis for the findings requisite to the issuance or continuance of a permit or license by the Commission.
Title 10 of the Code of Federal Regulations, Section 50.59, " Changes, Tests, and Experiments,"
(10 CFR 50.59) states, in Subsection (a)(1):
The holder of a license authorizing operation of a production or utilization facility may (1) make changes in the facility as described in the safety analysis report, (ii) make changes in the procedures as described in the safety analysis repod, and (iii) conduct tests or experiments not described in the safety analysis report, without prior Commission approval, unless the proposed change, test or experiment involves a change in the technical specification incorporated i.: the license or an unreviewed safety question.
The NRC issued RG 1.139, titled " Guidance for Residual Heat Removal," only as a draft for comment in May 1978. The RG was never issued in a final form. However, most of its contents were incorporated into SRP Section 5.4.7, " Residual Heat Removal (RHR) System,"
in April 1984.' The " Regulatory Position" section of the draft RG stated that "The systems
' in SRP 5.4.7 (paragraph 111.5). this statement was revised to state:"...the reviewer determines that the system has the capacity in brinq the rer Wr to Conditions permitting operation of the RHR system in a reasonable period of time, assuming a single failure of an ar tive component with only either onsite or offsite electric power available. For the purposes of this review,36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> is considered a reasonable time period." It should be noted that the SRP guidance of 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> only relates to achieving the reactor operating conditions that permit I
operation of the RHR system and not for achieving cold shutdown. Since the actual plant operating conditions during RHR operation vary significantly from plant to plant, the NRC staff's position in the SRP allowed flexibility in the time to achieve cold shutdown, and did not require that a plant should be in cold shutdown within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
D i
j R. Norway '
t should be capable of bringing the reactor to a cold-shutdown condition within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> following shutdown with only offsite power or onsite power available, assuming the most limiting single failure." In NMP2 UFSAR Table 1.8-1, NMPC states that NMP2 complies with the Regulatory Position of RG 1.139 (Revision 0 as issued for comment) through the alternate approach as described in Table 1.8-1.
Section 15.2.9 of the NMP2 UFSAR presents NMPC's evaluation of failures for the RHR shutdown cooling mode of operation. For the worst-case analysis, the single recirculation loop suction valve (located inside the containment) to the redundant RHR loops is assumed to fail in the closed position, making ooth shutdown loops inoperable. The UFSAR describes two different methods for establishing ASC assuming only one division of the RHR is available. The first alternate method (hereafter called the " preferred lineup") would involve taking suction from the suppression pool, with the fluid then directed through the RHR pumps B and C and heat exchanger B, into the reactor vessel, exiting the reactor vessel through the safety relief valves (SRVs), and returning to the suppress;on pool. The estimated time to achieve cold shutdown using this method is 35 hours4.050926e-4 days <br />0.00972 hours <br />5.787037e-5 weeks <br />1.33175e-5 months <br />.
The second alternate method (hereafter celled the " alternate lineup") uses the available RHR pump A for suppression pool cooling, while the other pump in the same division (Division I-Low Pressure Core Spray) is then used for vessel injection, with flow exiting the vessel through the SRVs. The estimated time to achieve cold shutdown using this method is 54 hours6.25e-4 days <br />0.015 hours <br />8.928571e-5 weeks <br />2.0547e-5 months <br />.
EVALUATION Operating experience at NMP2 has shown that the normal shutdown cooling method, using the turbine bypass system and the main condenser with offsite power available, is capab!a of achieving cold shutdown in less than 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. When the norrnal shutdown cooling method is not available, alternative methods are available of reaching cold shutdown. Mr. Norway contends that the licensee's commitment to draft RG 1.139 means that.two ASC methods must be capable of achieving cold shutdown within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. As discussed below, the NRC Headquarters staff finds tnat the draft RG 1.139 is met at NMP2 because the normal shutdown cooling method and one ASC method are capable of achieving cold shutdown within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
NRC Region 1 conducted an inspection of the NMP2 ASC method during the period May 18-June 28,1997 and reported its findings in IR 50-220/97-04 and 50-410/97-04 on July 30,1997.
To evaluate Mr. Norway's expressed concern, NRC Headquarters staff reviewed IR Section 02.4," Unit 2 Alternate Shutdown Cooling." The IR states that the NRC inspectors reviewed two shutdown procedures that implement the UFSAR licensing commitments: N2-OP 31 and N2-SOP-31, both titled " Loss of Shutdown Cooling."
Since the " alternate lineup" for ASC was estimated to achieve the cold shutdown condition within 54 hours6.25e-4 days <br />0.015 hours <br />8.928571e-5 weeks <br />2.0547e-5 months <br />, NMPC performed an evaluation in accordance with 10 CFR 50.59 (safety evaluation) to determine if this was in compliance with the guidance contained in RG 1.139.
NMPC concluded that the " preferred lineup" of ASC provided adequate redundancy to the normal shutdown cooling method (used when offsite power is available) and met the guidance contained in RG 1.139 (i.e., the cold shutdown condition would be achieved in less than 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />). NMPC also recognized that the " alternate lineup," which takes 54 hours6.25e-4 days <br />0.015 hours <br />8.928571e-5 weeks <br />2.0547e-5 months <br />, did not need to meet the 36-hour guideline of RG 1.139; rather, the " alternate lineup" was provided for l
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H. Norway i-October 6, 1999 op; ration l fi:xibility. As nottd in the IR, tho insp:ctors found th:sa NMPC conclusions to be ecc pt:bl3.
On the basis of its review, the NRC Headquarters staff agrees with the inspector's conclusions.
As explained in the IR, the " preferred lineup" method takes less than the 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> specified in the RG Therefore, since the normal shutdowr cooling system (undt r normal conditions) and one ASC (urider off-normal conditions) can achieve cold shutdown within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />, NMP2 is in compliance with the commitment to follow RG 1.139 as stated in UFSAR Table 1.8-1. There is no requirement to demonstrate a second alternate shutdown method when the licensee has already demonstrated compliance of one alternate method with on-site power and the most limiting single failure--the failure of the common RHR shutdown suction path. The NRC Headquarters staff agrees with the positions expressed by NMPC and the IR that the second alternate method need not meet the 36-hour guideline to be in compliance with RG 1.139.
Although slower, the second alternate shutdown method does provide operational flexibility.
With respect to the specific actio' ns requested in the Petition, since NMPC has performed calculations and developed detailed procedures that are consistent with RG 1.139, NMPC does riot need to take any exceptions from RG 1.139. The IR indicates that NMPC performed adequate engineering and safety evaluations for the ASC method. The review by NRC r
Headquarters staff reveals no reason to doubt this finding in the IR. Thus, since NMPC meets its UFSAR statement with respect to following the guidelines of RG 1.139, there is no need to modify the NMP2 operating license, nor for NMPC to re-perform its safety evaluation or demonstrate that all previously analyzed accident limits are not exceeded. Similarly, there is no need for the NRC to post NMPC's ASD safety evaluation, or related sections of the IR, on the internet. The full text of the IR is already publicly available in the Public Document Rooms.
NMPC's sa'm 'aluations, which demonstrate in accordance with 10 CFR 50.59 whether or not an unreviewe,d safety question exists, are maintained at the NMP2 site, where they are available for NRC audit, and copies are not available for the NRC to post on the internet or to otherwise make oublicly available.
I trust the at:w e. valuation by NRC Headquarters staff has been responsive to your expressed technical concern. Thank you for sharing your concern for public health and safety with the NRC. If you have questions regarding this letter, or wish to express other safety concerns, please do not hesitate M contact our Project Mcnager, Darl Hood, by phone at (301) 415-3049, or by e-mail at dsh@r,x. gov.
Sincerely, ORIGINAL SIGNED BY S. BAJWA FOR:
Elinor G. Adensam, Director Project Directorate l Division of Licensing Project Management Office of Nuclear Reactor Regulation 1
Cxket Nos. 50-220 and 50-410 cc: See next page DOCUMENT NAME: G:\\PDI-1\\NMP1-2\\NORW6348.WPD I To receive a copy of this document, indicate in the box: "C" = Copy "N" = No copy "2" = sie previous concurrence OFFICE PM;PDI-l lC LA:PDI-ljl) l SC:PDI-1 A l
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I R. Norway. l operational flexibility. As noted in the IR, the inspectors found these NMPC conclusions to be l
acceptable.
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On the basis of its review, the NRC Headquarters staff agrees with the inspector's conclusions.
As explained in the IR, the " preferred lineup" method takes less than the 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> specified in the RG. Therefore, since the normal shutdown cooling system (under normal conditions) and one ASC (under off normal conditions) can achieve cold shutdown within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />, NMP2 is in compliance with the commitment to follow RG 1.139 as stated in UFSAR Table 1.8-1. There is no requirement tc demonstrate a second alternate shutdown method when the licensee has already demonstrated compliance of one alternate method with on-site power and the most limiting single failure--the failure of the common RHR shutdown suction path. The NRC Headquarters staff agrees with the positions expressed by NMPC and the IR that the second alternate method need not meet the 36-hour guideline to be in compliance with RG 1.139.
Although slower, the second alternate shutdown method does provide operational flexibility.
With respect to the specific actions requested in the Petition, since NMPC has performed calculations and developed detailed procedures that are consistent with RG 1.139, NMPC does not need to take any exceptions from RG 1.139. The IR indicates that NMPC performed adequate engineering and safety evaluations for the ASC method. The review by NRC Headquarters staff reveals no reason to doubt this finding in the IR. Thus, since NMPC meets its UFSAR statement with respect to following the guidelines of RG 1.139, there is no need to modify the NMP2 operating license, r'or for NMPC to re-perform its safety evaluation or demonstrate that all previously analyzed accident limits are not exceeded. Similarly, there is no need for the NRC to post NMPC's ASD safety evaluation, or related sections of the IR, on the internet. The full text of the IR is already publicly available in the Public Document Rooms.
NMPC's safety evaluations, which demonstrate in accordance with 10 CFR 50.59 whether or not an unreviewed safety question exists, are maintained at the NMP2 site, where they are available for NRC audit, and copies are not available for the NRC to post on the internet or to otherwise make publicly available.
I trust the above evaluation by NRC Headquarters staff has been responsive to your expressed technical concern. Thank you for sharing your concern for public health and safety with the NRC. If you have questions regarding this letter, or wish to express other safety concerns, please do not hesitate to contact our Project Manager, Darl Hood, by phone at (301) 415-3049, or by e-mail at dsh @nrc. gov.
Sincerely, f
Elinor G. Adensam, Director Project Directorate i Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-220 and 50-410 cc: See next page
Nine Mile Point Nuclear Station Unit Nos.1 and 2 Regional Administrator, Region l Charles Donaldson, Esquire U.S. Nuclear Regulatory Commission-Assistant Attorney General 475 Allendale Road New York Department of Law
' King of Prussia, PA 19406 120 Broadway New York, NY 10271 Resident inspector U.S. Nuclear Regulatory Commission Mr. Paul D. Eddy
- P.O. Box 126 State of New York Department of Lycoming, NY 13093 Public Service Power Division, System Operations Mr. Jim Rettberg 3 Empire State Plaza New York State Electric & Gas Albany, NY 12223 Corporation Corporate Drive Mr. Timothy S. Carey Kirkwood Industrial Park Chair and Executive Director P.O. Box 5224 State Consumer Protection Board Binghamton, NY 13902-5224 5 Empire State Plaza, Suite 2101 Albany, NY 12223 Supervisor Town of Scriba Mark J. Wetterhahn, Esquire Route 8, Box 382 Winston & Strawn Oswego, NY 13126 1400 L Street, NW Washington, DC 20005-3502 Mr. Richard Goldsmith Syracuse University Gary D. Wilson, Esquire College of Law Niagara Mohawk Power Corporation E.I. White Hall Campus 300 Erie Boulevard West Syracuse, NY 12223 Syracuse, NY 13202 Mr. John V. Vinquist, MATS Inc.
Mr. F. William Valentino, President P.O. Box 63 New York State Energy, Research, Lycoming NY 13093 and Development Authority Corporate Plaza West 286 Washington Avenue Extension Albany, NY 12203-6399 e-
I.,
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R. Norway
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