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| | issue date = 03/31/2008 | | | issue date = 03/31/2008 |
| | title = Request for Additional Information Related to LAR to Revise TS 3.7.8, Essential Service Water System, and TS 3.8.1, AC Sources - Operating, for One-time Completion Time Extension Re Underground Piping | | | title = Request for Additional Information Related to LAR to Revise TS 3.7.8, Essential Service Water System, and TS 3.8.1, AC Sources - Operating, for One-time Completion Time Extension Re Underground Piping |
| | author name = Thadani M C | | | author name = Thadani M |
| | author affiliation = NRC/NRR/ADRO/DORL/LPLIV | | | author affiliation = NRC/NRR/ADRO/DORL/LPLIV |
| | addressee name = Naslund C D | | | addressee name = Naslund C |
| | addressee affiliation = Union Electric Co | | | addressee affiliation = Union Electric Co |
| | docket = 05000483 | | | docket = 05000483 |
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| =Text= | | =Text= |
| {{#Wiki_filter:March 31, 2008 | | {{#Wiki_filter:March 31, 2008 Mr. Charles D. Naslund Senior Vice President and Chief Nuclear Officer Union Electric Company Post Office Box 620 Fulton, MO 65251 |
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| Mr. Charles D. Naslund | |
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| Senior Vice President and Chief Nuclear Officer | |
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| Union Electric Company | |
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| Post Office Box 620 | |
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| Fulton, MO 65251 | |
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| ==SUBJECT:== | | ==SUBJECT:== |
| CALLAWAY PLANT, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO LICENSE AMENDMENT REQUEST FOR ONE-TIME EXTENSION OF COMPLETION TIME FOR INOPERABLE ESSENTIAL | | CALLAWAY PLANT, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO LICENSE AMENDMENT REQUEST FOR ONE-TIME EXTENSION OF COMPLETION TIME FOR INOPERABLE ESSENTIAL SERVICE WATER SYSTEM (TAC NO. MD7252) |
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| SERVICE WATER SYSTEM (TAC NO. MD7252) | |
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| ==Dear Mr. Naslund:== | | ==Dear Mr. Naslund:== |
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| By application dated October 31, 2007, as supplemented by letter dated February 21, 2008, Union Electric Company (the licensee) requested the U.S. Nuclear Regulatory Commission (NRC) staff approval of a one-time change to the Technical Specifications (TS) for its Callaway | | By application dated October 31, 2007, as supplemented by letter dated February 21, 2008, Union Electric Company (the licensee) requested the U.S. Nuclear Regulatory Commission (NRC) staff approval of a one-time change to the Technical Specifications (TS) for its Callaway Plant. |
| | | The proposed change would revise the TS to extend the completion time (CT) associated with an inoperable Essential Cooling Water train from 72 hours to 14 days, applicable once per train, and to be implemented prior to December 31, 2008. The licensee also proposed to eliminate the second CT applicable to TS 3.8.1, Condition B in accordance with the NRC staff-approved TS Task Force (TSTF) traveler TSTF-439. |
| Plant. | | The NRC staff has reviewed the information provided in your submittal and determined that additional information is required in order to complete its review. Please provide a response to the enclosed questions by May 15, 2008, to facilitate the continuation of the review by the NRC staff. In the absence of your response by the requested date, the NRC staff may proceed to deny your request pursuant to Title 10 of the Code of Federal Regulations, Part 2, Section 108, for not responding to this request within the time specified by the NRC staff. |
| | | If there are any questions, please contact me at (301) 415-1476, or e-mail mct@nrc.gov. |
| The proposed change would revise the TS to extend the completion time (CT) associated with | | Sincerely, |
| | | /RA/ |
| an inoperable Essential Cooling Water train from 72 hours to 14 days, applicable once per train, and to be implemented prior to December 31, 2008. The licensee also proposed to eliminate | | Mohan C. Thadani, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-483 |
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| the second CT applicable to TS 3.8.1, Condition B in accordance with the NRC staff-approved | |
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| TS Task Force (TSTF) traveler TSTF-439. | |
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| The NRC staff has reviewed the information provided in your submittal and determined that | |
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| additional information is required in order to complete its review. Please provide a response to | |
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| the enclosed questions by May 15, 2008, to facilitate the continuation of the review by the NRC | |
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| staff. In the absence of your response by the requested date, the NRC staff may proceed to | |
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| deny your request pursuant to Title 10 of the Code of Federal Regulations, Part 2, Section 108, for not responding to this request within the time specified by the NRC staff. | |
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| If there are any questions, please contact me at (301) 415-1476, or e-mail mct@nrc.gov. | |
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| Sincerely, | |
| /RA/ Mohan C. Thadani, Senior Project Manager
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| Plant Licensing Branch IV | |
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| Division of Operating Reactor Licensing | |
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| Office of Nuclear Reactor Regulation | |
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| Docket No. 50-483 | |
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| ==Enclosure:== | | ==Enclosure:== |
| As stated | | As stated cc w/encl: See next page |
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| cc w/encl: See next page | |
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| ML (*) memo dated OFFICE NRR/LPL4/PM NRR/LPL4/LA DSS/APLA/BC NRR/LPL4/BC NAME MThadani, JBurkhardt MRubin (*) THiltz DATE 3/31/08 3/31/08 3/24/08 3/31/08 Callaway Plant, Unit 1 (November 2007)
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| cc:
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| John O'Neill, Esq.
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| Pillsbury Winthrop Shaw Pittman LLP
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| 2300 N. Street, N.W.
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| Washington, D.C. 20037
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| Mr. Tom Elwood, Supervising Engineer
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| Regulatory Affairs and Licensing
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| AmerenUE P.O. Box 620
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| Fulton, MO 65251
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| Mr. Les H. Kanuckel, Manager
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| Quality Assurance
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| AmerenUE P.O. Box 620
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| Fulton, MO 65251
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| Mr. Luke Graessle, Manager
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| Regulatory Affairs
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| AmerenUE P.O. Box 620
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| Fulton, MO 65251
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| Mr. Scott Maglio
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| Assistant Manager, Regulatory Affairs
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| AmerenUE P.O. Box 620
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| Fulton, MO 65251
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| U.S. Nuclear Regulatory Commission
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| Resident Inspector Office
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| 8201 NRC Road
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| Steedman, MO 65077-1302
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| Missouri Public Service Commission
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| Governor Office Building
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| 200 Madison Street
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| P.O. Box 360
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| Jefferson City, MO 65102-0360
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| Regional Administrator, Region IV
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| U.S. Nuclear Regulatory Commission
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| 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-4005
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| Mr. H. Floyd Gilzow Deputy Director for Policy
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| Department of Natural Resources
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| P.O. Box 176
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| Jefferson City, MO 65102-0176
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| Mr. Rick A. Muench, President and CEO
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| Wolf Creek Nuclear Operating Corporation
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| P.O. Box 411
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| Burlington, KA 66839
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| Certrec Corporation
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| 4200 South Hulen, Suite 422 Fort Worth, TX 76109
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| Technical Services Branch Chief
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| FEMA Region VII
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| 2323 Grand Boulevard, Suite 900
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| Kansas City, MO 64108-2670
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| Kathleen Logan Smith, Executive Director
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| and Kay Drey, Representative, Board of
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| Directors
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| Missouri Coalition for the Environment
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| 6267 Delmar Blvd., Suite 2E
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| St. Louis, City, MO 63130
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| Mr. Lee Fritz, Presiding Commissioner
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| Callaway County Courthouse
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| 10 East Fifth Street
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| Fulton, MO 65251
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| Mr. Keith G. Henke, Planner III
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| Division of Community and Public Health
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| Office of Emergency Coordination
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| Missouri Department of Health and
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| Senior Services
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| 930 Wildwood Drive
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| P.O. Box 570
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| Jefferson City, MO 65102
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| Mr. Scott Clardy, Director
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| Section for Environmental Public Health
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| Missouri Department of Health and
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| Senior Services
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| 930 Wildwood Drive
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| P.O. Box 570
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| Jefferson City, MO 65102 Director, Missouri State Emergency
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| Management Agency P.O. Box 116 Jefferson City, MO 65102-0116 OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR ADDITIONAL INFORMATION RELATED TO ESSENTIAL SERVICE WATER UNION ELECTRIC COMPANY CALLAWAY PLANT DOCKET NO. 50-483 By application dated October 31, 2007, as supplemented by letter dated February 21, 2008, Union Electric Company (the licensee) requested the U.S. Nuclear Regulatory Commission (NRC) staff approval of a one-time change to the Technical Specifications (TS) for its Callaway
| |
| | |
| Plant. The NRC staff has reviewed the information provided in your submittal and determined
| |
| | |
| that additional information is required in order to complete its review. Please provide a
| |
| | |
| response to the following request for additional information (RAI) questions by May 15, 2008, to
| |
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| facilitate the continuation of the review by the NRC staff:
| |
| : 1. The NRC staff asked for substantive justification that the known deficiencies in the probabilistic risk assessment (PRA) model, identified from peer reviews and identified to
| |
| | |
| the NRC staff in the submittal, would not significantly impact the application. In
| |
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| response, to address the Scientech gap assessment against the American Society of
| |
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| Mechanical Engineers internal events standard, the licensee restated that it "believed" these gaps would not invalidate the risk insights for this application, then argued that
| |
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| since the existing PRA results were already greater than the Regulatory Guide 1.177
| |
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| guidelines for permanent changes, the gaps would not result in any further significant
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| increase in the risk.
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| Please submit specific information which qualitatively discusses the substance of the
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| deficient items and adequately justifies that these deficiencies or gaps do not impact the
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| risk results of this application.
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| : 2. The NRC staff asked for discussion and justification of the truncation level for this application. The licensee's response identified the use of pre-solved cutsets to generate
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| the application risk results. The staff is concerned that the use of pre-solved cutsets for
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| this application may not be adequate to obtain an accurate assessment of the
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| configuration-specific risk level. Specific ally, the service water unavailability and random failure probability, coincident with the unavailability or failure of the backup normal
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| service water system (identified in other RAI responses as credited in the model),
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| represents a very unlikely failure mode, which may not appear in many cutsets above
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| truncation. Regenerating the cutsets with the service water train out-of-service to reflect
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| the actual configuration during the proposed extended completion time (CT) could result
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| in many more cutsets generated above the nominal truncation level, resulting in an
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| increase in the configuration-specific risk. This can be an especially significant problem
| |
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| if the nominal unavailability and random failure probability result in large numbers of
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| cutsets just below the truncation level. In addition, initiating events, such as
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| loss-of-service water, are more likely to occur when one of the two trains is out-of-service. This frequency increase may not be reflected in the pre-solved cutsets, and, therefore, the risk contribution from such initiators would not be reflected in the
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| results.
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| Please provide risk results which avoid this potential non-conservatism by regenerating
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| cutsets for the specific configuration(s) expected as result of the changes requested and
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| addressing the increased likelihood of the loss-of-service water initiating event.
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| : 3. The NRC staff requested the licensee to address initiating events not included in its risk assessment model, including fires, floods, seis mic events, and other external events.
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| The licensee identified proposed compensatory measures, to include walkdowns of the
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| operable service water train, fire and flood watches in rooms identified as risk important
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| in the licensee's internal flooding, seismic margin, and fire protection evaluations, and
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| evaluation of transient combustibles within 20 feet of the operable service water train.
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| The staff is unable to conclude that these sources of risk will not be potentially significant
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| while the plant configuration has one service water header unavailable.
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| (a) With regard to seismic risk, there is no risk mitigation provided by the compensatory measure of walkdowns of rooms identified as risk-important in a
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| seismic margins analysis. Please provide a summary of the relationship between
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| the results of the seismic margins analyses which it identified in its response with
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| the specific configuration of the plant when it is reliant upon a single service
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| water header. The seismic ruggedness of the remaining operable service water
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| system should be addressed to justify that a seismic event is not likely to cause
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| damage to this system. The qualitative information should be adequate for the
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| NRC staff to conclude that seismic risk is not significant for this application.
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| Otherwise, additional quantified estimates should be provided to characterize the
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| risk impact.
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| (b) With regard to internal flooding, the NRC staff agrees that the compensatory measure of verifying the availability of flood mitigation equipment for the
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| protected train is beneficial. However, the NRC staff needs to understand the
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| significant contributors to internal flooding risk, how these could potentially
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| impact the remaining operable protected train of equipment, or otherwise result in
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| increased reliance upon that equipment, and either conclude that the risk of
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| these scenarios is not significant or that compensatory measures are in place to
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| mitigate these events. Please provide adequate qualitative information for the
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| NRC staff to determine whether the internal flooding risk is not significant for this
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| application. Otherwise, please provide additional quantified estimates enable the
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| NRC staff to characterize the risk impact.
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| (c) Similar to internal fires, the compensatory measures identified for walkdowns and monitoring of transient combustibles is a benefit. The staff must understand the
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| significant contributors to fire risk, how these could potentially impact the
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| remaining operable protected train of equipment or otherwise result in increased
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| reliance upon that equipment, and either conclude that the risk of these
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| scenarios is not significant or that compensatory measures are in place to
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| mitigate these events. Please provide adequate qualitative information for the
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| NRC staff to determine whether the fire risk is not significant for this application.
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| Otherwise, provide additional quantified estimates to characterize the risk impact.
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| (d) Please discuss the impact of this proposed TS change on other external events (i.e., hazardous material leaks, transportation events, high winds and tornadoes, etc.). Although weather-related loss-of-offsite power was addressed (and
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| credited in the risk analyses), there is no discussion of high winds with regard to
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| any unique vulnerabilities during the time the service water header is out of
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| service, the vulnerability of the backup normal service water system to high
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| winds, or other discussion to characterize the site with regard to this source of
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| risk. Other external events were not discussed at all.
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| : 4. The NRC staff previously requested the licensee to address sources of uncertainty in the risk analyses which may be significant for this application. In response, the licensee
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| stated, without justification or basis, that the assumptions applied and the use of point
| |
| | |
| estimates of mean values would not invalidate the risk analyses. For the specific areas
| |
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| identified by the NRC staff as examples of key assumptions, the licensee identified the
| |
| | |
| methodologies used in the risk analyses, but did not provide any assessment as to the
| |
| | |
| impact of uncertainties associated with these assumptions on the application.
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| The purpose of this RAI was to request the licensee to review the important PRA
| |
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| assumptions and elements of the model which are especially relevant to the risk of the
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| plant configuration with one service water header unavailable, to characterize the impact
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| of these uncertainties, and to develop and present its basis as to why these sources of
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| uncertainty do not adversely impact the result s of the risk analyses relevant to the NRC staff decision to accept a 14-day extended CT. Please provide a more specific technical
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|
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| justification for your conclusions that the uncertainties do not affect the risk analyses.
| | ML (*) memo dated OFFICE NRR/LPL4/PM NRR/LPL4/LA DSS/APLA/BC NRR/LPL4/BC NAME MThadani, JBurkhardt MRubin (*) THiltz DATE 3/31/08 3/31/08 3/24/08 3/31/08 Callaway Plant, Unit 1 (November 2007) cc: |
| With regard specifically to equipment repair credit, please identify what equipment
| | John ONeill, Esq. Mr. H. Floyd Gilzow Pillsbury Winthrop Shaw Pittman LLP Deputy Director for Policy 2300 N. Street, N.W. Department of Natural Resources Washington, D.C. 20037 P.O. Box 176 Jefferson City, MO 65102-0176 Mr. Tom Elwood, Supervising Engineer Regulatory Affairs and Licensing Mr. Rick A. Muench, President and CEO AmerenUE Wolf Creek Nuclear Operating Corporation P.O. Box 620 P.O. Box 411 Fulton, MO 65251 Burlington, KA 66839 Mr. Les H. Kanuckel, Manager Certrec Corporation Quality Assurance 4200 South Hulen, Suite 422 AmerenUE Fort Worth, TX 76109 P.O. Box 620 Fulton, MO 65251 Technical Services Branch Chief FEMA Region VII Mr. Luke Graessle, Manager 2323 Grand Boulevard, Suite 900 Regulatory Affairs Kansas City, MO 64108-2670 AmerenUE P.O. Box 620 Kathleen Logan Smith, Executive Director Fulton, MO 65251 and Kay Drey, Representative, Board of Mr. Scott Maglio Directors Assistant Manager, Regulatory Affairs Missouri Coalition for the Environment AmerenUE 6267 Delmar Blvd., Suite 2E P.O. Box 620 St. Louis, City, MO 63130 Fulton, MO 65251 Mr. Lee Fritz, Presiding Commissioner U.S. Nuclear Regulatory Commission Callaway County Courthouse Resident Inspector Office 10 East Fifth Street 8201 NRC Road Fulton, MO 65251 Steedman, MO 65077-1302 Mr. Keith G. Henke, Planner III Missouri Public Service Commission Division of Community and Public Health Governor Office Building Office of Emergency Coordination 200 Madison Street Missouri Department of Health and P.O. Box 360 Senior Services Jefferson City, MO 65102-0360 930 Wildwood Drive P.O. Box 570 Regional Administrator, Region IV Jefferson City, MO 65102 U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Mr. Scott Clardy, Director Arlington, TX 76011-4005 Section for Environmental Public Health Missouri Department of Health and Senior Services 930 Wildwood Drive P.O. Box 570 Jefferson City, MO 65102 |
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| repairs are credited, the numerical value and basis for such credit, and the specific
| | P.O. Box 116 Director, Missouri State Emergency Jefferson City, MO 65102-0116 Management Agency |
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| impact to the risk metrics for this application. (Note that the NRC staff position does not | | OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR ADDITIONAL INFORMATION RELATED TO ESSENTIAL SERVICE WATER UNION ELECTRIC COMPANY CALLAWAY PLANT DOCKET NO. 50-483 By application dated October 31, 2007, as supplemented by letter dated February 21, 2008, Union Electric Company (the licensee) requested the U.S. Nuclear Regulatory Commission (NRC) staff approval of a one-time change to the Technical Specifications (TS) for its Callaway Plant. The NRC staff has reviewed the information provided in your submittal and determined that additional information is required in order to complete its review. Please provide a response to the following request for additional information (RAI) questions by May 15, 2008, to facilitate the continuation of the review by the NRC staff: |
| | : 1. The NRC staff asked for substantive justification that the known deficiencies in the probabilistic risk assessment (PRA) model, identified from peer reviews and identified to the NRC staff in the submittal, would not significantly impact the application. In response, to address the Scientech gap assessment against the American Society of Mechanical Engineers internal events standard, the licensee restated that it "believed" these gaps would not invalidate the risk insights for this application, then argued that since the existing PRA results were already greater than the Regulatory Guide 1.177 guidelines for permanent changes, the gaps would not result in any further significant increase in the risk. |
| | Please submit specific information which qualitatively discusses the substance of the deficient items and adequately justifies that these deficiencies or gaps do not impact the risk results of this application. |
| | : 2. The NRC staff asked for discussion and justification of the truncation level for this application. The licensee's response identified the use of pre-solved cutsets to generate the application risk results. The staff is concerned that the use of pre-solved cutsets for this application may not be adequate to obtain an accurate assessment of the configuration-specific risk level. Specifically, the service water unavailability and random failure probability, coincident with the unavailability or failure of the backup normal service water system (identified in other RAI responses as credited in the model), |
| | represents a very unlikely failure mode, which may not appear in many cutsets above truncation. Regenerating the cutsets with the service water train out-of-service to reflect the actual configuration during the proposed extended completion time (CT) could result in many more cutsets generated above the nominal truncation level, resulting in an increase in the configuration-specific risk. This can be an especially significant problem if the nominal unavailability and random failure probability result in large numbers of cutsets just below the truncation level. In addition, initiating events, such as loss-of-service water, are more likely to occur when one of the two trains is |
|
| |
|
| permit PRA credit for repair and restoration of any equipment subject to the extended CT
| | out-of-service. This frequency increase may not be reflected in the pre-solved cutsets, and, therefore, the risk contribution from such initiators would not be reflected in the results. |
| | Please provide risk results which avoid this potential non-conservatism by regenerating cutsets for the specific configuration(s) expected as result of the changes requested and addressing the increased likelihood of the loss-of-service water initiating event. |
| | : 3. The NRC staff requested the licensee to address initiating events not included in its risk assessment model, including fires, floods, seismic events, and other external events. |
| | The licensee identified proposed compensatory measures, to include walkdowns of the operable service water train, fire and flood watches in rooms identified as risk important in the licensee's internal flooding, seismic margin, and fire protection evaluations, and evaluation of transient combustibles within 20 feet of the operable service water train. |
| | The staff is unable to conclude that these sources of risk will not be potentially significant while the plant configuration has one service water header unavailable. |
| | (a) With regard to seismic risk, there is no risk mitigation provided by the compensatory measure of walkdowns of rooms identified as risk-important in a seismic margins analysis. Please provide a summary of the relationship between the results of the seismic margins analyses which it identified in its response with the specific configuration of the plant when it is reliant upon a single service water header. The seismic ruggedness of the remaining operable service water system should be addressed to justify that a seismic event is not likely to cause damage to this system. The qualitative information should be adequate for the NRC staff to conclude that seismic risk is not significant for this application. |
| | Otherwise, additional quantified estimates should be provided to characterize the risk impact. |
| | (b) With regard to internal flooding, the NRC staff agrees that the compensatory measure of verifying the availability of flood mitigation equipment for the protected train is beneficial. However, the NRC staff needs to understand the significant contributors to internal flooding risk, how these could potentially impact the remaining operable protected train of equipment, or otherwise result in increased reliance upon that equipment, and either conclude that the risk of these scenarios is not significant or that compensatory measures are in place to mitigate these events. Please provide adequate qualitative information for the NRC staff to determine whether the internal flooding risk is not significant for this application. Otherwise, please provide additional quantified estimates enable the NRC staff to characterize the risk impact. |
| | (c) Similar to internal fires, the compensatory measures identified for walkdowns and monitoring of transient combustibles is a benefit. The staff must understand the significant contributors to fire risk, how these could potentially impact the remaining operable protected train of equipment or otherwise result in increased reliance upon that equipment, and either conclude that the risk of these scenarios is not significant or that compensatory measures are in place to mitigate these events. Please provide adequate qualitative information for the NRC staff to determine whether the fire risk is not significant for this application. |
| | Otherwise, provide additional quantified estimates to characterize the risk impact. |
|
| |
|
| to be used in the calculation of the risk metrics.)}} | | (d) Please discuss the impact of this proposed TS change on other external events (i.e., hazardous material leaks, transportation events, high winds and tornadoes, etc.). Although weather-related loss-of-offsite power was addressed (and credited in the risk analyses), there is no discussion of high winds with regard to any unique vulnerabilities during the time the service water header is out of service, the vulnerability of the backup normal service water system to high winds, or other discussion to characterize the site with regard to this source of risk. Other external events were not discussed at all. |
| | : 4. The NRC staff previously requested the licensee to address sources of uncertainty in the risk analyses which may be significant for this application. In response, the licensee stated, without justification or basis, that the assumptions applied and the use of point estimates of mean values would not invalidate the risk analyses. For the specific areas identified by the NRC staff as examples of key assumptions, the licensee identified the methodologies used in the risk analyses, but did not provide any assessment as to the impact of uncertainties associated with these assumptions on the application. |
| | The purpose of this RAI was to request the licensee to review the important PRA assumptions and elements of the model which are especially relevant to the risk of the plant configuration with one service water header unavailable, to characterize the impact of these uncertainties, and to develop and present its basis as to why these sources of uncertainty do not adversely impact the results of the risk analyses relevant to the NRC staff decision to accept a 14-day extended CT. Please provide a more specific technical justification for your conclusions that the uncertainties do not affect the risk analyses. |
| | With regard specifically to equipment repair credit, please identify what equipment repairs are credited, the numerical value and basis for such credit, and the specific impact to the risk metrics for this application. (Note that the NRC staff position does not permit PRA credit for repair and restoration of any equipment subject to the extended CT to be used in the calculation of the risk metrics.)}} |
Letter Sequence RAI |
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TAC:MD7252, Eliminate Second Completion Times Limiting Time from Discovery of Failure to Meet an LCO (Approved, Closed) |
Results
Other: ML083100134, ULNRC-05476, One-Time Completion Time Extension for Essential Service Water (ESW) System, ULNRC-05482, Response to Questions Received on February 7, 2008 Regarding Amendment to Revise Technical Specifications for Essential Service Water, ULNRC-05520, One-Time Completion Time Extension for Essential Service Water (ESW) System, (OL1281), ULNRC-05534, One-Time Completion Time Extension for Essential Service Water (ESW) System
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MONTHYEARML0725504882007-08-30030 August 2007 10 CFR 50.55a Request: Proposed Alternative to ASME Section Xi Requirements for Replacement of Class 3 Buried Piping Project stage: Request ULNRC-05445, One-Time Completion Time Extension for Essential Service Water (ESW) System2007-10-31031 October 2007 One-Time Completion Time Extension for Essential Service Water (ESW) System Project stage: Request ML0800400232008-01-0808 January 2008 Forthcoming Meeting with Union Electric Company on the Callaway Plant Relief and Amendment Requests Dated August 3 and October 31, 2007. (Tac No. MD6792 and MD7252) Project stage: Meeting ULNRC-05476, One-Time Completion Time Extension for Essential Service Water (ESW) System2008-02-21021 February 2008 One-Time Completion Time Extension for Essential Service Water (ESW) System Project stage: Other ML0803806472008-02-29029 February 2008 Summary of Meeting with Union Electric Company Callaway Plant, Unit 1, 8/30/2007 Relief Request and 10/31/2007 License Amendment Request Applications Related to Replacement of Essential Service Water Piping (Tac No. MD6792 and MD7252) Project stage: Meeting ULNRC-05482, Response to Questions Received on February 7, 2008 Regarding Amendment to Revise Technical Specifications for Essential Service Water2008-03-0707 March 2008 Response to Questions Received on February 7, 2008 Regarding Amendment to Revise Technical Specifications for Essential Service Water Project stage: Other ML0808800122008-03-31031 March 2008 Request for Additional Information Related to LAR to Revise TS 3.7.8, Essential Service Water System, and TS 3.8.1, AC Sources - Operating, for One-time Completion Time Extension Re Underground Piping Project stage: RAI ULNRC-05500, Response to Request for Additional Information One-Time Completion Time Extension for Essential Service Water (ESW) System2008-05-0606 May 2008 Response to Request for Additional Information One-Time Completion Time Extension for Essential Service Water (ESW) System Project stage: Response to RAI ML0815800112008-06-10010 June 2008 Request for Additional Information, Relief Request No. 13R-10 and License Amendment Request to Revise TS 3.7.8, Essential Service Water System, and TS 3.8.1, AC Sources - Operating, for One-time CT Extension Underground Piping Project stage: RAI ML0817506442008-06-24024 June 2008 Forthcoming Meeting with Union Electric Company on the Callaway Plant to Discuss the Licensee'S Responses to NRC Request for Additional Information Relief and License Amendment Requests Project stage: RAI ULNRC-05520, One-Time Completion Time Extension for Essential Service Water (ESW) System, (OL1281)2008-07-10010 July 2008 One-Time Completion Time Extension for Essential Service Water (ESW) System, (OL1281) Project stage: Other ULNRC-05534, One-Time Completion Time Extension for Essential Service Water (ESW) System2008-08-13013 August 2008 One-Time Completion Time Extension for Essential Service Water (ESW) System Project stage: Other ML0828106432008-10-31031 October 2008 Issuance of Amendment No. 186, Revise TS 3.7.8, Essential Service Water System, and TS 3.8.1, AC Sources - Operating, for One-time Completion Time Extension Re Underground Piping Project stage: Approval ML0831001342008-11-0606 November 2008 Correction to Amendment No. 186 Approving One-Time Extension of Completion Time for Inoperable Essential Service Water System and Emergency Diesel Generators Project stage: Other ML0834503272008-12-19019 December 2008 Summary of Meeting with Representatives of Union Electric Company, Licensee for Callaway Plant, Unit 1 Second Round of Requests for Information, Extension of Completion Time for Essential Service Water Systems (TAC Nos. MD6792 & MD7252) Project stage: Meeting 2008-02-29
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Category:Letter
MONTHYEARIR 05000483/20244032024-08-28028 August 2024 Security Baseline Inspection 05000483-2024-403 IR 05000483/20253012024-08-0505 August 2024 Notification of NRC Initial Operator Licensing Examination 05000483/2025301 ML24212A2822024-08-0202 August 2024 Regulatory Audit Summary Concerning Review of Request No. C3R-01 for Proposed Alternative to ASME Code, Section XI Requirements for Containment Building Inspections IR 05000483/20240022024-07-18018 July 2024 and Independent Spent Fuel Storage Installation Integrated Inspection Report 05000483/2024002 and 07201045/2024001 ML24185A1032024-07-16016 July 2024 2024 Biennial Problem Identification and Resolution Inspection Report ULNRC-06891, Independent Spent Fuel Storage Installation, Registration of Dry Spent Fuel Storage Canister HGMPC00052024-06-26026 June 2024 Independent Spent Fuel Storage Installation, Registration of Dry Spent Fuel Storage Canister HGMPC0005 ULNRC-06892, Independent Spent Fuel Storage Installation Registration of Dry Spent Fuel Storage Canister HGMPC00062024-06-26026 June 2024 Independent Spent Fuel Storage Installation Registration of Dry Spent Fuel Storage Canister HGMPC0006 ULNRC-06884, Independent Spent Fuel Storage Installation, Registration of Dry Spent Fuel Storage Canister HGMPC00022024-06-12012 June 2024 Independent Spent Fuel Storage Installation, Registration of Dry Spent Fuel Storage Canister HGMPC0002 ULNRC-06885, Independent Spent Fuel Storage Installation, Registration of Dry Spent Fuel Storage Canister HGMPC00032024-06-12012 June 2024 Independent Spent Fuel Storage Installation, Registration of Dry Spent Fuel Storage Canister HGMPC0003 ULNRC-06886, Independent Spent Fuel Storage Installation, Registration of Dry Spent Fuel Storage Canister HGMPC00042024-06-12012 June 2024 Independent Spent Fuel Storage Installation, Registration of Dry Spent Fuel Storage Canister HGMPC0004 ML24144A0492024-06-11011 June 2024 Requests for Relief from ASME OM Code Pump and Valve Testing Requirements for Fifth 120-Month Inservice Testing Interval ML24178A1132024-06-0606 June 2024 Ameren Missouris Intent to Adopt Revision 1 to Amendment 0 of Certificate of Compliance No. 1040 as Applicable to the ISFSI at the Callaway Plant Site ML24158A5222024-06-0606 June 2024 Application to Revise Technical Specifications to Adopt Tstf-569, Rev. 2, Revise Response Time Testing Definition (LDCN 24-0008) ML24143A1632024-05-23023 May 2024 Independent Spent Fuel Storage Installation Registration of Dry Spent Storage Canister HGMPC0001 ML24137A2342024-05-16016 May 2024 Independent Spent Fuel Storage Installation - Registration of Dry Spent Fuel Storage Canister HGMPC0011 ULNRC-06882, Independent Spent Fuel Storage Installation Registration of Dry Spent Fuel Storage Canister HGMPC00122024-05-16016 May 2024 Independent Spent Fuel Storage Installation Registration of Dry Spent Fuel Storage Canister HGMPC0012 ML24122A1502024-05-0707 May 2024 Audit Plan to Support Review of Steam Generator License Renewal Response to Commitment Nos 34 and 35 IR 05000483/20244022024-05-0606 May 2024 Security Baseline Inspection Report 05000483/2024402 (Full Report) ULNRC-06877, Final Safety Analysis Report Revision OL-27 and Technical Specification Bases Revision 252024-05-0606 May 2024 Final Safety Analysis Report Revision OL-27 and Technical Specification Bases Revision 25 ULNRC-06856, CFR 50.59 and 10 CFR 72.48 Summary Report2024-05-0101 May 2024 CFR 50.59 and 10 CFR 72.48 Summary Report IR 05000483/20240112024-05-0101 May 2024 NRC Post-Approval Site Inspection for License Renewal (Phase 2) Report 05000483/2024011 ML24122A1132024-04-30030 April 2024 Submittal of Callaway, Unit 1, 2023 Annual Radioactive Effluent Release Report ULNRC-06869, Submittal of Callaway, Unit 1, 2023 Annual Radiological Environmental Operating Report2024-04-30030 April 2024 Submittal of Callaway, Unit 1, 2023 Annual Radiological Environmental Operating Report ULNRC-06876, Registration of Dry Spent Fuel Storage Canister HGMPC00102024-04-25025 April 2024 Registration of Dry Spent Fuel Storage Canister HGMPC0010 ULNRC-06872, Independent Spent Fuel Storage Installation, Registration of Dry Spent Fuel Storage Canister HGMPC00082024-04-17017 April 2024 Independent Spent Fuel Storage Installation, Registration of Dry Spent Fuel Storage Canister HGMPC0008 ULNRC-06866, Submittal of Cycle 26 Commitment Change Summary Report2024-04-17017 April 2024 Submittal of Cycle 26 Commitment Change Summary Report ML24108A1082024-04-17017 April 2024 Independent Spent Fuel Storage Installation Registration of Dry Spent Fuel Storage Canister HGMPC0009 ULNRC-06871, Independent Spent Fuel Storage Installation, Registration of Dry Spent Fuel Storage Canister HGMPC00072024-04-17017 April 2024 Independent Spent Fuel Storage Installation, Registration of Dry Spent Fuel Storage Canister HGMPC0007 IR 05000483/20240012024-04-16016 April 2024 Integrated Inspection Report 05000483/2024001 IR 05000483/20244042024-04-0909 April 2024 Cyber Security Inspection Report 05000483/2024404 05000483/LER-2024-001, Submittal of LER 2024-001-00 for Callaway Plant, Unit 1, Reactor Trip Due to Turbine Trip2024-04-0404 April 2024 Submittal of LER 2024-001-00 for Callaway Plant, Unit 1, Reactor Trip Due to Turbine Trip ML24088A3212024-04-0101 April 2024 Notification of Commercial Grade Dedication Inspection (05000483/2024013) and Request for Information ML24086A5132024-03-26026 March 2024 CFR 50.46 Annual Report Regarding ECCS Evaluation Model Revisions ULNRC-06863, Submittal of Annual Exposure Report for 20232024-03-20020 March 2024 Submittal of Annual Exposure Report for 2023 ML24079A1622024-03-19019 March 2024 Re Nuclear Property Insurance Reporting ML24066A1932024-03-0707 March 2024 2024 Callaway Plant Notification of Biennial Problem Identification and Resolution Inspection and Request for Information ULNRC-06852, Owners Activity Reports (OAR-1 Forms) for Cycle/Refuel 262024-03-0505 March 2024 Owners Activity Reports (OAR-1 Forms) for Cycle/Refuel 26 IR 05000483/20230062024-02-28028 February 2024 Annual Assessment Letter for Callaway Plant Report 05000483/2023006 ML24052A3662024-02-26026 February 2024 Regulatory Audit Plan in Support of Proposed Alternative to ASME Code, Section XI Requirements for Containment Building Inspections IR 05000483/20230022024-02-21021 February 2024 Amended Integrated Inspection Report 05000483/2023002 ULNRC-06858, Completion of License Renewal Activities Prior to Entering the Period of Extended Operation2024-02-21021 February 2024 Completion of License Renewal Activities Prior to Entering the Period of Extended Operation ML24036A1712024-02-20020 February 2024 Exemption from Select Requirements of 10 CFR Part 73 (EPID L-2023-LLE-0079 (Security Notifications, Reports, and Recordkeeping and Suspicious Activity Reporting)) ULNRC-06853, Submittal of 2023 Fitness for Duty Performance Data Per Per 10 CFR 26.7172024-01-29029 January 2024 Submittal of 2023 Fitness for Duty Performance Data Per Per 10 CFR 26.717 IR 05000483/20230042024-01-19019 January 2024 Integrated Inspection Report 05000483/2023004 ML24008A0552024-01-19019 January 2024 Acceptance of Requested Licensing Action - Proposed Alternative to the Requirements of the ASME Code (EPID L-2023-LLR- 0061) ML23353A1712024-01-18018 January 2024 Issuance of Amendment No. 237 to Clarify Support System Requirements for the Residual Heat Removal System and Control Room Air Conditioning System Under Technical Specifications 3.4.8, 3.7.11, and 3.9.6 ML23317A0012024-01-12012 January 2024 Audit Summary Regarding LAR to Clarify Support System Requirements for the Residual Heat Removal and Control Room Air Conditioning System Under Technical Specifications 3.4.8, 3.7.11, and 3.9.6 ML24011A1492024-01-11011 January 2024 Notification of Post-Approval Site Inspection for License Renewal and Request for Information (05000483/2024011) ML23347A1212024-01-11011 January 2024 Issuance of Amendment No. 236 to Adopt TSTF-501, Revision 1, Relocate Stored Fuel Oil and Lube Volume Values to Licensee Control EPID L-2023-LLA-0046) ULNRC-06847, Supplement to Relief Request from Requirements of ASME BPV Code, Section XI, Subsection Iwl Regarding Examination and Testing of the Unbonded Post-Tensioning System (Relief Request C3R-01)2023-12-21021 December 2023 Supplement to Relief Request from Requirements of ASME BPV Code, Section XI, Subsection Iwl Regarding Examination and Testing of the Unbonded Post-Tensioning System (Relief Request C3R-01) 2024-08-05
[Table view] Category:Request for Additional Information (RAI)
MONTHYEARML24066A1932024-03-0707 March 2024 2024 Callaway Plant Notification of Biennial Problem Identification and Resolution Inspection and Request for Information ML23200A2982023-07-19019 July 2023 NRR E-mail Capture - Callaway Plant, Unit 1 - Final Request for Additional Information (RAI) - Request for Approval of Oqam, Revision 36a - EPID L-2023-LLQ-0000 ML23174A1272023-06-23023 June 2023 Cw FFD Document Request List 2023 ML23158A1462023-06-13013 June 2023 Notification of Post-Approval Site Inspection for License Renewal and Request for Information Inspection (05000483/2023010) ML23163A1572023-06-0606 June 2023 In-service Inspection Request for Information ML23096A0072023-04-0505 April 2023 NRR E-mail Capture - Final Request for Additional Information - Callaway Plant, Unit 1 - License Amendment Request to Revise TS 5.5.16 for Permanent Extension of Integrated Leak Rate Testing - EPID L-2022-LLA-0165 ML23080A1382023-03-21021 March 2023 Notification of Inspection (NRC Inspection Report 05000483/2023003) and Request for Information ML23073A0262023-03-13013 March 2023 NRR E-mail Capture - Final - Request for Additional Information - Callaway Plant, Unit 1 - SG Inspection Report Review - EPID L-2022-LRO-0143 ML23037A7092023-02-0606 February 2023 April 2023 Emergency Preparedness Exercise Inspection - Request for Information ML23026A0212023-01-24024 January 2023 NRR E-mail Capture - Final - Request for Additional Information - Callaway Plant, Unit 1 - LAR for Proposed Changes to TS for SFP - ML22287A0952022-10-14014 October 2022 NRR E-mail Capture - Final - Request for Additional Information - Callaway Plant, Unit 1 - License Amendment Request for Adoption of Alternate Source Term and Revision of Technical Specifications - EPID L-2021-LLA-0177 ML22269A4312022-09-26026 September 2022 November 2022 Emergency Preparedness Program Inspection - Request for Information ML22173A0562022-06-22022 June 2022 Information Request, Security IR 2022402 ML22167A0252022-06-15015 June 2022 NRR E-mail Capture - Final - Request for Additional Information - Callaway Plant, Unit 1 - LAR for Proposed Revision to Radiological Emergency Response Plan Regarding Response & Notification Goals - EPID L-2022-LLA-0024 ML22157A0572022-06-0606 June 2022 Notification of NRC Design Bases Assurance Inspection (Programs) (05000483/2022013) and Request for Information ML22154A0122022-06-0202 June 2022 NRR E-mail Capture - Final - Request for Additional Information - Callaway Plant, Unit 1 - License Amendment Request for Adoption of Alternate Source Term and Revision of Technical Specifications - EPID L-2021-LLA-0177 ML22151A0512022-05-27027 May 2022 NRR E-mail Capture - Final - Request for Additional Information - Columbia Generating Station - LAR to Change TS 3.4.11 - Reactor Coolant System Pressure and Temperature Limits - EPID L-2021-LLA-0191 ML22137A0292022-05-16016 May 2022 NRR E-mail Capture - Draft - Request for Additional Information - Callaway Plant, Unit 1 - License Amendment Request for Adoption of Alternate Source Term and Revision of Technical Specifications - EPID L-2021-LLA-0177 ML22096A0232022-04-0505 April 2022 NRR E-mail Capture - Callaway Plant - Final RAIs - License Amendment and Regulatory Exemptions for a Risk-Informed Approach to Address Generic Safety Issue - 191 and Respond to GL 2004-02 (EPIDs L-2021-LLA-0059 and L-2021-LLE-0021) ML21336A6392021-12-0202 December 2021 .05 Sec Doc Request ML21319A0062021-11-30030 November 2021 Supplemental Information Needed for Acceptance of Requested Licensing Actions License Amendment Request for Adoption of Alternate Source Term and Revision of Technical Specifications ML21258A0382021-09-14014 September 2021 NRR E-mail Capture - Final - Request for Additional Information - Callaway, Unit 1 - LAR to Adopt 10 CFR 50.69, Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors- EPID L-2020-LLA-023 ML21159A2352021-06-17017 June 2021 Notification of NRC Triennial Heat Exchanger/Heat Sink Performance Inspection (05000483/2021003) and Request for Information ML21130A5882021-05-11011 May 2021 Supplemental Information Needed for Acceptance of Requested Licensing Actions to Adopt a Risk-Informed Approach to Address GSI-191 and Respond to Generic Letter 2004 02 ML21088A3872021-03-30030 March 2021 Notification of Evaluations of Changes, Tests, and Experiments Inspection (Inspection Report 05000483/2021002) and Request for Information ML21007A1622021-01-0606 January 2021 NRR E-mail Capture - Final - Request for Additional Information - (COVID-19) Callaway Plant, Unit 1 - Additional Request for Exemption from Specific Requirements of 10 CFR Part 26, Fitness for Duty Programs - EPID L-2021-LLE-0242 ML20203M3682020-07-21021 July 2020 NRR E-mail Capture - Draft Request for Additional Information - Callaway Plant, Unit 1 - License Amendment Request - Revision to Technical Specification (TS) 5.3.1 and Deletion of TS 5.3.1.1 and 5.3.1.2 - EPID L-2020-LLA-0046 ML20162A1882020-06-10010 June 2020 Request for Supporting Information for the Callaway SPRA Audit Review - Draft Supplement ML20280A5442020-03-25025 March 2020 Cwy 2020 PIR Request for Information ML20064B6582020-02-27027 February 2020 Second, Third, and Fourth Request for Information for Callaway Dba Teams Inspection 2020011 ML19317E6332019-11-13013 November 2019 Request for Supporting Information for the Callaway SPRA Audit Review ML19107A5152019-04-11011 April 2019 Cwy 2019410 RFI Cyber Security Gap ML19078A2932019-03-18018 March 2019 Notification of an NRC Triennial Fire Protection Baseline Inspection (NRC Inspection Report 05000483/2019010) and Request for Information ML19023A2032019-01-22022 January 2019 Notification of NRC Triennial Heat Sink Performance Inspection (05000483/2019001) and Request for Information ML19009A3442019-01-0909 January 2019 NRR E-mail Capture - Formal Release of RAIs Ref: Callaway Plant Class 1E LAR, L-2018-LLA-0062 ML18355A4882018-12-20020 December 2018 NRR E-mail Capture - Formal Release of RAI Ref: Callaway Plant EAL Changes, L-2018-LLA-0239 ML18331A2052018-11-27027 November 2018 NRR E-mail Capture - Formal Release of RAIs Ref: Callaway Relief Request EPID L-2018-LLR-0051 ML18025B4672018-01-24024 January 2018 NRR E-mail Capture - Request for Extension of Due Date for RAI Response ML17304B1912017-10-31031 October 2017 NRR E-mail Capture - Requests for Additional Information Concerning Callaway License Amendment - Thermal Overload Protection ML17142A1352017-05-19019 May 2017 Notification of NRC Design Bases Assurance Inspection (05000483/2017007) and Initial Request for Information ML17115A0622017-04-25025 April 2017 NRR E-mail Capture - Requests for Additional Information -- Callaway Plant, Unit 1, Technical Specification 5.6.5, Core Operating Limits Report CAC MF8463 ML17038A2292017-02-0707 February 2017 NRR E-mail Capture - RAI Formal Release for Callaway SG Tube Inspection Report, MF8474 ML16111B3222016-04-20020 April 2016 Notification of Evaluations of Changes, Tests, and Experiments, and Permanent Plant Modifications Inspection (05000483/2016007) and Request for Information ML15316A1532015-11-12012 November 2015 Request for Additional Information Email, Relief Request 13R-11 (Pressurizer Welds) from Code Case N-460 Requirements, Third 10-Year Inservice Inspection Interval ML15096A0942015-04-0606 April 2015 Notification of Inspection (NRC Inspection Report 05000483/2015003) and Request for Information ML14353A1172014-12-22022 December 2014 Request for Additional Information, Round 3, License Amendment Request to Revise Final Safety Analysis Report Standard Plant Section 3.6 for High Density Polyethylene (Hdpe) Crack Exclusion ML14294A7752014-10-28028 October 2014 Request for Additional Information, Round 2, License Amendment Request to Revise Final Safety Analysis Report Standard Plant Section 3.6 for High Density Polyethylene (Hdpe) Crack Exclusion ML14203A0632014-07-25025 July 2014 Request for Additional Information, Relief Request I3R-17, Proposed Alternative to ASME Code, Section XI Requirements, Which Extends Rv ISI Frequency from 10 to 20 Years, Third 10-Year ISI Interval ML14178A8232014-07-0101 July 2014 Request for Additional Information, License Amendment Request to Revise Final Safety Analysis Report- Standard Plant Section 3.6 for High Density Polyethylene (Hdpe) Crack Exclusion ULNRC-06117, Callaway Plant, Unit 1, License Revewal Application, Request for Additional Information (RAI) Set 31 Responses2014-04-24024 April 2014 Callaway Plant, Unit 1, License Revewal Application, Request for Additional Information (RAI) Set 31 Responses 2024-03-07
[Table view] |
Text
March 31, 2008 Mr. Charles D. Naslund Senior Vice President and Chief Nuclear Officer Union Electric Company Post Office Box 620 Fulton, MO 65251
SUBJECT:
CALLAWAY PLANT, UNIT 1 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO LICENSE AMENDMENT REQUEST FOR ONE-TIME EXTENSION OF COMPLETION TIME FOR INOPERABLE ESSENTIAL SERVICE WATER SYSTEM (TAC NO. MD7252)
Dear Mr. Naslund:
By application dated October 31, 2007, as supplemented by letter dated February 21, 2008, Union Electric Company (the licensee) requested the U.S. Nuclear Regulatory Commission (NRC) staff approval of a one-time change to the Technical Specifications (TS) for its Callaway Plant.
The proposed change would revise the TS to extend the completion time (CT) associated with an inoperable Essential Cooling Water train from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days, applicable once per train, and to be implemented prior to December 31, 2008. The licensee also proposed to eliminate the second CT applicable to TS 3.8.1, Condition B in accordance with the NRC staff-approved TS Task Force (TSTF) traveler TSTF-439.
The NRC staff has reviewed the information provided in your submittal and determined that additional information is required in order to complete its review. Please provide a response to the enclosed questions by May 15, 2008, to facilitate the continuation of the review by the NRC staff. In the absence of your response by the requested date, the NRC staff may proceed to deny your request pursuant to Title 10 of the Code of Federal Regulations, Part 2, Section 108, for not responding to this request within the time specified by the NRC staff.
If there are any questions, please contact me at (301) 415-1476, or e-mail mct@nrc.gov.
Sincerely,
/RA/
Mohan C. Thadani, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-483
Enclosure:
As stated cc w/encl: See next page
ML (*) memo dated OFFICE NRR/LPL4/PM NRR/LPL4/LA DSS/APLA/BC NRR/LPL4/BC NAME MThadani, JBurkhardt MRubin (*) THiltz DATE 3/31/08 3/31/08 3/24/08 3/31/08 Callaway Plant, Unit 1 (November 2007) cc:
John ONeill, Esq. Mr. H. Floyd Gilzow Pillsbury Winthrop Shaw Pittman LLP Deputy Director for Policy 2300 N. Street, N.W. Department of Natural Resources Washington, D.C. 20037 P.O. Box 176 Jefferson City, MO 65102-0176 Mr. Tom Elwood, Supervising Engineer Regulatory Affairs and Licensing Mr. Rick A. Muench, President and CEO AmerenUE Wolf Creek Nuclear Operating Corporation P.O. Box 620 P.O. Box 411 Fulton, MO 65251 Burlington, KA 66839 Mr. Les H. Kanuckel, Manager Certrec Corporation Quality Assurance 4200 South Hulen, Suite 422 AmerenUE Fort Worth, TX 76109 P.O. Box 620 Fulton, MO 65251 Technical Services Branch Chief FEMA Region VII Mr. Luke Graessle, Manager 2323 Grand Boulevard, Suite 900 Regulatory Affairs Kansas City, MO 64108-2670 AmerenUE P.O. Box 620 Kathleen Logan Smith, Executive Director Fulton, MO 65251 and Kay Drey, Representative, Board of Mr. Scott Maglio Directors Assistant Manager, Regulatory Affairs Missouri Coalition for the Environment AmerenUE 6267 Delmar Blvd., Suite 2E P.O. Box 620 St. Louis, City, MO 63130 Fulton, MO 65251 Mr. Lee Fritz, Presiding Commissioner U.S. Nuclear Regulatory Commission Callaway County Courthouse Resident Inspector Office 10 East Fifth Street 8201 NRC Road Fulton, MO 65251 Steedman, MO 65077-1302 Mr. Keith G. Henke, Planner III Missouri Public Service Commission Division of Community and Public Health Governor Office Building Office of Emergency Coordination 200 Madison Street Missouri Department of Health and P.O. Box 360 Senior Services Jefferson City, MO 65102-0360 930 Wildwood Drive P.O. Box 570 Regional Administrator, Region IV Jefferson City, MO 65102 U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Mr. Scott Clardy, Director Arlington, TX 76011-4005 Section for Environmental Public Health Missouri Department of Health and Senior Services 930 Wildwood Drive P.O. Box 570 Jefferson City, MO 65102
P.O. Box 116 Director, Missouri State Emergency Jefferson City, MO 65102-0116 Management Agency
OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR ADDITIONAL INFORMATION RELATED TO ESSENTIAL SERVICE WATER UNION ELECTRIC COMPANY CALLAWAY PLANT DOCKET NO. 50-483 By application dated October 31, 2007, as supplemented by letter dated February 21, 2008, Union Electric Company (the licensee) requested the U.S. Nuclear Regulatory Commission (NRC) staff approval of a one-time change to the Technical Specifications (TS) for its Callaway Plant. The NRC staff has reviewed the information provided in your submittal and determined that additional information is required in order to complete its review. Please provide a response to the following request for additional information (RAI) questions by May 15, 2008, to facilitate the continuation of the review by the NRC staff:
- 1. The NRC staff asked for substantive justification that the known deficiencies in the probabilistic risk assessment (PRA) model, identified from peer reviews and identified to the NRC staff in the submittal, would not significantly impact the application. In response, to address the Scientech gap assessment against the American Society of Mechanical Engineers internal events standard, the licensee restated that it "believed" these gaps would not invalidate the risk insights for this application, then argued that since the existing PRA results were already greater than the Regulatory Guide 1.177 guidelines for permanent changes, the gaps would not result in any further significant increase in the risk.
Please submit specific information which qualitatively discusses the substance of the deficient items and adequately justifies that these deficiencies or gaps do not impact the risk results of this application.
- 2. The NRC staff asked for discussion and justification of the truncation level for this application. The licensee's response identified the use of pre-solved cutsets to generate the application risk results. The staff is concerned that the use of pre-solved cutsets for this application may not be adequate to obtain an accurate assessment of the configuration-specific risk level. Specifically, the service water unavailability and random failure probability, coincident with the unavailability or failure of the backup normal service water system (identified in other RAI responses as credited in the model),
represents a very unlikely failure mode, which may not appear in many cutsets above truncation. Regenerating the cutsets with the service water train out-of-service to reflect the actual configuration during the proposed extended completion time (CT) could result in many more cutsets generated above the nominal truncation level, resulting in an increase in the configuration-specific risk. This can be an especially significant problem if the nominal unavailability and random failure probability result in large numbers of cutsets just below the truncation level. In addition, initiating events, such as loss-of-service water, are more likely to occur when one of the two trains is
out-of-service. This frequency increase may not be reflected in the pre-solved cutsets, and, therefore, the risk contribution from such initiators would not be reflected in the results.
Please provide risk results which avoid this potential non-conservatism by regenerating cutsets for the specific configuration(s) expected as result of the changes requested and addressing the increased likelihood of the loss-of-service water initiating event.
- 3. The NRC staff requested the licensee to address initiating events not included in its risk assessment model, including fires, floods, seismic events, and other external events.
The licensee identified proposed compensatory measures, to include walkdowns of the operable service water train, fire and flood watches in rooms identified as risk important in the licensee's internal flooding, seismic margin, and fire protection evaluations, and evaluation of transient combustibles within 20 feet of the operable service water train.
The staff is unable to conclude that these sources of risk will not be potentially significant while the plant configuration has one service water header unavailable.
(a) With regard to seismic risk, there is no risk mitigation provided by the compensatory measure of walkdowns of rooms identified as risk-important in a seismic margins analysis. Please provide a summary of the relationship between the results of the seismic margins analyses which it identified in its response with the specific configuration of the plant when it is reliant upon a single service water header. The seismic ruggedness of the remaining operable service water system should be addressed to justify that a seismic event is not likely to cause damage to this system. The qualitative information should be adequate for the NRC staff to conclude that seismic risk is not significant for this application.
Otherwise, additional quantified estimates should be provided to characterize the risk impact.
(b) With regard to internal flooding, the NRC staff agrees that the compensatory measure of verifying the availability of flood mitigation equipment for the protected train is beneficial. However, the NRC staff needs to understand the significant contributors to internal flooding risk, how these could potentially impact the remaining operable protected train of equipment, or otherwise result in increased reliance upon that equipment, and either conclude that the risk of these scenarios is not significant or that compensatory measures are in place to mitigate these events. Please provide adequate qualitative information for the NRC staff to determine whether the internal flooding risk is not significant for this application. Otherwise, please provide additional quantified estimates enable the NRC staff to characterize the risk impact.
(c) Similar to internal fires, the compensatory measures identified for walkdowns and monitoring of transient combustibles is a benefit. The staff must understand the significant contributors to fire risk, how these could potentially impact the remaining operable protected train of equipment or otherwise result in increased reliance upon that equipment, and either conclude that the risk of these scenarios is not significant or that compensatory measures are in place to mitigate these events. Please provide adequate qualitative information for the NRC staff to determine whether the fire risk is not significant for this application.
Otherwise, provide additional quantified estimates to characterize the risk impact.
(d) Please discuss the impact of this proposed TS change on other external events (i.e., hazardous material leaks, transportation events, high winds and tornadoes, etc.). Although weather-related loss-of-offsite power was addressed (and credited in the risk analyses), there is no discussion of high winds with regard to any unique vulnerabilities during the time the service water header is out of service, the vulnerability of the backup normal service water system to high winds, or other discussion to characterize the site with regard to this source of risk. Other external events were not discussed at all.
- 4. The NRC staff previously requested the licensee to address sources of uncertainty in the risk analyses which may be significant for this application. In response, the licensee stated, without justification or basis, that the assumptions applied and the use of point estimates of mean values would not invalidate the risk analyses. For the specific areas identified by the NRC staff as examples of key assumptions, the licensee identified the methodologies used in the risk analyses, but did not provide any assessment as to the impact of uncertainties associated with these assumptions on the application.
The purpose of this RAI was to request the licensee to review the important PRA assumptions and elements of the model which are especially relevant to the risk of the plant configuration with one service water header unavailable, to characterize the impact of these uncertainties, and to develop and present its basis as to why these sources of uncertainty do not adversely impact the results of the risk analyses relevant to the NRC staff decision to accept a 14-day extended CT. Please provide a more specific technical justification for your conclusions that the uncertainties do not affect the risk analyses.
With regard specifically to equipment repair credit, please identify what equipment repairs are credited, the numerical value and basis for such credit, and the specific impact to the risk metrics for this application. (Note that the NRC staff position does not permit PRA credit for repair and restoration of any equipment subject to the extended CT to be used in the calculation of the risk metrics.)