ML051930570
| ML051930570 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 07/11/2005 |
| From: | Weinkam E Nuclear Management Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| GL-04-002, L-H U-05-015 | |
| Download: ML051930570 (4) | |
Text
mmiiW&Ni&x!rExce#encrr Nuclear Management Company, LLC July 11,2005 L-H U-05-0 1 5 10 CFR 50.54(f)
U. S. Nuclear Regulatory Commission AlTN: Document Control Desk 1 I555 Rockville Pike Rockville, Maryland 20852 Palisades Nuclear Plant Docket 50-255 License No. DPR-20 Prairie Island Nuclear Generating Plant Units 1 and 2 Dockets 50-282 and 50-306 License Nos, DPR-42 and DPR-60 Nuclear Manaaement Com~any Response to Request for Additlonal Information on Generic Letter 2004-02. "Potential lm~act of Debris Blockaae on Emeraencv Recirculation Durlncl Desirrn Basis Accidents at Pressurized Water Reactors" By letter dated March 7,2005, Nuclear Management Company, LLC (NMC) provided the 90-day response to Generic Letter (GL) 2004-02. Subsequent to this, NMC received a request for additional information (RAI), Enclosure I contains the NMC response for the above listed nuclear plants. The NMC response was prepared in accordance with the guidance of the June 30,2005, document entitled, "NRC Staff Responses to Industry Questions on Generic Letter 2004-02."
Summaw of Commitments This letter contains no new commitments and no revisions to existing commitments.
700 First Street Hudson, Wisconsin 54016 Telephone: 71 5.377.3300
Document Control Desk Page 2 I declare under penalty of pe jury that the foregoing is true and correct. Executed on July 1 1, 2005.
Director, Regulatory Services Nuclear Management Company, LLC Enclosure (I )
Administrator, Region Ill, USNRC Project Manager, Palisades Nuclear Plant, Prairie Island Nuclear Generating Plant, USNRC Resldent Inspector, Palisades Nuclear Plant, Prairie Island Nuclear Generating Plant Units 1 and 2, USNRC
ENCLOSURE 1 NUCLEAR MANAGEMENT COMPANY, LLC RAI RESPONSE TO GENERIC LETTER 2004-02 Nuclear Reglulatoty Commission (NRC) Requested lnformatlon By letter dated March 7,2005, Nuclear Managemenf Company, LL C, (the licensee) provided the 90-day response to U. S. Nuclear Regulatory Commission (NRC) Genetic Letter (GL) 2004-02 for Palisades Plant and Prairie Island Nuclear Generating Plant, Units 1 and 2. The GL requested that addressees perJom an evaluafion offhe emergency core cooling systerr, and containment spray system recirculation functions in light of fhe information provided in the GL and, if appropriafe, take additional actions to ensure sysfem function. Additionally, addressees were requested to submit to the NRC the informa fion specified in the GL. The staff has completed ifs preliminary review of your response and has determined it needs the following additional information to complete our review:
In your 9Oday response to GL 2004-02, you indica fed that you intend to use future test resues, industry guidance, and NRC guidance to account for chemical precipitants in your evaluation and their availabi/ify will impact the schedule for pehrming an evaluation. The cooperative NRC-Elecfric Power Research institute tests in progress at the Universify of New Mexico are designed to determine if chemical effects occur, but are not designed to measure head loss associated with any chemical effects. The staff notes thaf some chemical effecfs have been obsewed in the initial three tests.
In your 80-day response to GL 2004-02, you also indicated that you intend to use industry owners ' group guidance and component manufacturer data to evaluate long-term performance degradation of downstream suscepfibie components caused by debris-laden fluid and their availability will impact the schedule for performing an evaluation.
For bofh of these issues, you sfated the evaluation may occur after the September I, 2005, response due date, depending on the schedule for tesfing and the availability of industry guidance. This is contrary to fhe information request in GL 2004-02, which requests that chemical and downstream effects be addressed in the September 1, 2005, response. This delay is also contrary to the staff's position that there are sufficienf bases to address sump vulnerability to chemical effects and that the September response will be incomplete if the evaluation is incomplete, the design is not complefe, or there is no schedule for upgrades. In this light, please discuss your plans and schedule for evaluating chemical effects and the longterm downstream e ffecfs. In addition, please discuss any plans for performing testing to suppott your evaluation of these effects.
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Nuclear Management Company (NMC), LLC Response NMC provided the 90-day response to Generic Letter (GL) 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors," based on the information available at that time.
Additional information pertaining to chemical effects and downstream effects has subsequently become available.
WCAP-16406-P, "Evaluation of Downstream Sump Debris Effects in Support of GSI-19 t," was made available. WCAP-16406-P provides guidance for assessing the downstream impact of sump debris on the performance of emergency core cooling systems (ECCS) following a loss-of-coolant accident (LOCA). NMC plans to apply the methodology outlined in the WCAP-16406-P, along with industry data and manufacturer's data, to the downstream effects evaluations of each plant. NMC plans on performing these evaluations in support of the September 7,2005, response to GL 2004-02. However, the evaluations may not be finalized until a detailed design of the strainer is complete, as the final strainer design may affect the parameters applied in the evaluations. In addition, the downstream effects evaluations are based on methodologies that have not been approved by the Nuclear Regulatory Commission (NRC). Therefore, these evaluations may need to be revised at a later date when industrial and regulatory standards are established.
The Integrated Chemical Effects Testing (ICET) program has indicated that precipitant material may be formed under post-LOCA containment environment. The effects of this precipitant on screen head loss have not been quantified nor has a methodology been formulated for determining this component of the total head loss. NMC plans to pedorm an evaluation for each plant, addressing sump vulnerability to chemical effects in support of the September 1,2005, response to GL 2004-02. The evaluation wilt determine if the NRC-Electric Power Research Institute tests bound site-specific post-LOCA parameters, and will assess whether sufficient margin has been reserved in the strainer head loss design to account for chemical effects. The evaluations may not be finalized until a detailed design of the strainer is complete, as strainer specific testing (if required) could affect the analysis. In addition, as the guidance for addressing chemical effects is still being developed, these evaluations may need to be revised at a later date when additional guidance becomes available.
NMC plans to determine the extent of necessary testing when evaluating sump strainer options, as certain options may require additional testing based on plant specific design parameters, The testing, if required, wouldbe performed during detailed design of the strainer. NMC plans to install strainers no later than December 2007. Detailed design of the strainers will be completed in support of this schedule.
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