ML113120050
| ML113120050 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 01/13/2012 |
| From: | Sanders C Plant Licensing Branch 1 |
| To: | Heacock D Dominion Nuclear Connecticut |
| Sandeers, Carleen, NRR/DORL, 415-1603 | |
| References | |
| TAC ME6693 | |
| Download: ML113120050 (8) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555"()001 January 13, 2012 Mr. David A. Heacock President and Chief Nuclear Officer Dominion Nuclear Connecticut, Inc.
Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711
SUBJECT:
MILLSTONE POWER STATION, UNIT NO.2 - REQUEST FOR ADDITIONAL INFORMATION REGARDING REQUEST FOR EXMEPTION FROM TITLE 10 OF THE CODE OF FEDERAL REGULA TlONS, PART 50, APPENDIX R, SECTION III.G, "FIRE PROTECTION OF SAFE SHUTDOWN CAPABILITY" (TAC NO. ME6693)
Dear Mr. Heacock:
By letter dated June 30, 2011,1 Dominion Nuclear Connecticut, Inc., submitted a request for exemption from Title 10 of the Code of Federal Regulations, Part 50, Appendix R,Section III.G, "Fire Protection of Safe Shutdown Capability" for Millstone Power Station, Unit No.2 (MPS2).
The proposed exemption would allow the use of operator manual actions in lieu of the requirements of 10 CFR 50, Appendix R, Section III.G.2. To complete its review, the Nuclear Regulatory Commission staff requests responses to the enclosed questions.
The draft questions were sent to Mr. William Bartron, of your staff, to ensure that the questions were understandable, the regulatory basis for the questions was clear, and to determine if the information was previously docketed. On January 6,2012, Mr. William Bartron agreed that you would provide a response by February 29,2012.
If you have any questions regarding this matter, please contact me at 301-415-1603.
7IZ A L--
Carleen J. djders, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-336
Enclosure:
As stated cc w/encl: Distribution via Listserv 1 Agencywide Documents Access Management System Accession No. Ml11188A213
OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR ADDITIONAL INFORMATION EXEMPTION FROM 10 CFR 50, APPENDIX R, SECTION III.G FIRE PROTECTION OF SAFE SHUTDOWN CAPABILITY MILLSTONE POWER STATION, UNIT NO.2 DOCKET NO. 50-336 By letter dated June 30, 2011,1 Dominion Nuclear Connecticut, Inc. (DNC or the licensee),
submitted a request for exemption from Title 10 of the Code of Federal Regulations, Part 50, Appendix R,Section III.G, "Fire Protection of Safe Shutdown Capability" for Millstone Power Station, Unit No~ 2 (MPS2). The proposed exemption would allow the use of operator manual actions (OMAs) in lieu of the requirements of 10 CFR 50, Appendix R, Section III.G.2.
The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the information provided by the licensee and has determined that the following additional information is needed in order to complete the review.
RAI-01 Circumstances for Review In accordance with 10 CFR 50.12, the NRC will not consider granting an exemption unless special circumstances are present. Special circumstances are described in 10 CFR 50.12(a)(2).
Only one circumstance needs to be met. Although 10 CFR 50. 12(a)(2)(ii) is cited in the application, unwarranted burden is also mentioned. Unwarranted burden is the special circumstance described in 10 CFR 50.12(a)(2)(iii). In addition, the information supporting the special circumstance is inadequate. For example if 10 CFR 50.12(a)(2)(ii) is the special circumstance being met in this exemption, additional information on how the OMA's provide assurance that the underlying purpose of the rule is met is needed.
Please provide the following:
RAI-01.1 :
Clarify which special circumstance is being met?
RAI-01.2 Provide additional information supporting the special circumstance that is being met.
RAI-02 Ensuring That One of the Redundant Trains is Free of Fire Damage, Page 3, "Conclusion" of the submittal asserts that the OMAs discussed in the request provide assurance that one train of systems necessary to achieve and maintain hot 1 Agencywide Documents Access Management System Accession No. ML11188A213 Enclosure
~ 2 shutdown remains available in the event of a fire. Attachment 1, Sections 3.0 and 4.0 of the submittal contain a description of each of the OMAs and the time required to perform them, but does not state whether or how one of the redundant trains in a particular fire area is maintained free of fire damage. There is no discussion regarding fire damage and when it will occur.
RAI~02.1:
State the specific requirements of 10 CFR 50, Appendix R, Section III.G.2 that are not met for each of the requested exemptions, e.g., a lack of fire barriers, spatial separation, automatic suppression, etc.
RAI-02.2:
Provide a summary of the plant~specific features that compensate for the lack of 10 CFR 50, Appendix R, Section III.G.2-required features identified in RAI-02.1, for each of the requested exemptions. For example, note any enhanced defense-in~depth measures such as a lack of ignition sources and/or combustibles, more robust and/or supplemental detection and suppression systems and other physical or administrative controls.
RAI~02.3:
10 CFR 50, Appendix R establishes the concept of defense~in-depth and requires operators be able to safely and reliably achieve and maintain hot shutdown capability from the control room. Provide a technical explanation that justifies how the proposed methods will result in a level of protection that is commensurate with that intended by 10 CFR 50, Appendix R, Section III.G.2.
RAI~02.4:, Page 28, Section 4.0, "Fire Area R~2" of the submittal states that a fire will affect all Facility Z2 shutdown components and that Facility Z1 is used to achieve and maintain hot standby. Similar statements are made throughout the submittal including Attachment 1, page 34 for Fire Area R~7, page 35 for Fire Area R-8, etc. Provide a description of Facility Z1 and Facility Z2 shutdown components including all components, their locations, separation from each other, etc.
RAI-03 Other Evaluations Fire areas may have other exemptions or engineering evaluations that affect fire protection systems or safe shutdown capabilities.
RAI-03.1:
Provide a discussion of any other exemptions or evaluations, including licensee-developed evaluations, e.g., Generic Letter 86-10 evaluations that impact this request in any way and provide a justification for why such impact should be considered acceptable and how the analysis remains valid in light of this exemption request.
- 3 RAI-04 Fire Protection System and Fire Barrier Design Criteria, Section 2.0 of the submittal notes that several areas are equipped with various fire detection and suppression systems. However, the request does not state whether the systems have been designed and installed in accordance with recognized design standards.
RAI-04.1:
Where fire protection features such as detection and suppression systems and fire rated assemblies are installed, describe the technical basis for such installations including the applicable codes, standards and listings.
For example:, Section 2.0 of the submittal states that Fire Area R-14 contains portable fire extinguishers for suppression purposes, as well as ionization smoke detection that alarms at the main fire alarm panel in the control room. The submittal also states that hose stations and additional fire extinguishers are located in adjacent fire areas/zones.
However, Attachment 1, Section 2.0 of the submittal does not state whether these systems/equipment have been installed and maintained in accordance with a particular design standard or basis, e.g. National Fire Protection Association (NFPA) 72: National Fire Alarm Code, 1985 Edition.
RAI-04.2:
Provide a technical justification for any deviations from codes, standards and listings by independent testing laboratories in the fire areas that could impact this evaluation.
RAI-05 Ignition Sources and Combustible Fuel Load The submittal includes information for each of the fire areas including floor area, combustible loading, potential ignition sources, available fire protection equipment and systems, and fire prevention methods. Additional information is required for the NRC staff to complete its review.
RAI-05.1:
Provide the following additional information regarding the in situ and transient fire hazards that could threaten redundant equipment for each fire area included in the request:
The cable type, e.g., thermoplastic or thermoset. If thermoplastic cables are used, provide a discussion of self-ignited cable fires.
Actual dimensions of the rooms including ceiling heights (L x W x H).
RAI-OS Fire Scenarios The submittal identifies fire scenarios and the OMAs needed in each fire area, but does not describe, in detail, the fire scenarios that have been considered for the postulated events. The request mentions "cables of concern" and "the subject cables" but the NRC staff could not identify specifically what cables were being referred to.
-4 For example:
A fire that could potentially impact any cables of concern would likely involve diesel fuel oil. For a fire in Fire Area R-7, OMAs are required to provide decay heat removal and restore charging system flow to the RCS. However, no information is provided to describe the separation between the redundant train cables. It is also not clear where the cables are located relative to the floor, walls and other trains or whether any spatial separation exists between the two trains.
RAI-06.1:
Provide a description of the proximity of the credited redundant train equipment to in situ hazards. Also describe the spatial relationship between two redundant trains in the fire area such that if the redundant trains are damaged, manual actions would be necessary. Provide information on "cables of concern" or "subject cables" to indicate cable type, quantity, function, location, etc.
RAI-07 Staffing, Section 4.0 of the submittal states that it is assumed that there are three Plant Equipment Operators (PEOs) and a Reactor Operator available to perform the required OMAs and that there is an additional Appendix R PEO on shift in addition to the minimum staff identified in the Technical Specifications (TSs).
RAI-07.1:
Confirm that individuals that may be needed to perform the operator manual actions do not have collateral duties, such as firefighting, security duties, or control room operation, during a postulated fire event.
RAI-OS Time and Sequence Assumptions An action is considered feasible if it is shown that it is possible to be performed within the available time (considering relevant uncertainties in estimating the time available). Attachment 1, Section 4.0 of the submittal states that the walkdown time column includes diagnostic time as well as time to don personal protective equipment and obtain necessary tools. The OMA tables provide the action time (time to execute) separately. It is not apparent from the request that confirmation time was included in the time and sequence assumptions.
RAI-08.1:
Provide additional information regarding the confirmation time including information that demonstrates that the proposed OMAs are feasible.
RAI-09 Fire Area Proximity and Access, Section 2.0 of the submittal describes each fire area and includes statements about floor area, combustible loading, potential ignition sources, available fire protection equipment and systems, and fire prevention methods, but does not include any information about the nature and rating of the fire area boundaries or whether openings and penetrations exist in any rated barriers. Information about ventilation systems including how and when these systems activate and whether they have been designed to transport products of combustion
- 5 without causing additional damage to equipment or relocating the smoke to other fire areas has not been included.
RAI-09.1:
Provide detailed information on the nature and rating of all fire area boundaries including whether opening and penetrations exist in rated barriers. Provide a technical justification for any non-rated fire protection assemblies.
RAI-09.2:
Indicate whether the use of self-contained breathing apparatuses is necessary for each fire area or zone included in the request.
RAI-09.3:
For adjacent fire areas or where operators will pass within close proximity of the fire affected area, provide a technical justification that demonstrates that a fire in the fire area would not impact the performance of the OMA.
RAI-09.4:
Describe the ventilation systems in each area and state whether these ventilation systems are used for smoke evacuation or fire brigade operations and provide a justification for the systems capabilities.
RAI-10 Reliability of Actions, Section 4.0 of the submittal includes data to show that adequate margin exists for all the operator manual actions, which is an indicator of feasibility and reliability.
RAI-10.1 :
Where a particular amount of time has been allocated for diagnosing an event, demonstrate that the additional uncertainties such as recovery from unexpected delays, environmental factors, operator response to stress, etc. are addressed by this time.
RAI-10.2:
Provide a clear description of how the time needed to perform potential corrective or reactive actions in the event the action did not accomplish the desired result (i.e., "response not obtained") was factored into the OMA performance time and provide the technical basis for the time allotted for each reactive action.
RAI-11 Required Operator Stations The submittal does not specify what has been assumed for the location from which operators are dispatched to perform the OMAs or whether scenarios were evaluated where operators were not at their assumed locations at the beginning of an event.
The location or activities of required plant personnel when the fire starts could delay their participation in executing the operator manual actions (e.g., they may be in a location that is on the opposite side of the plant from the main control room or may need to restore certain equipment before being able to participate or both).
- 6 RAI-11.1 :
Provide a justification for the assumption that operators will be located at an assumed location when the OMA procedure begins. If there isn't assurance that the operators will be at the assumed locations, provide the times required for them to reach the locations and indicate how these times are reflected in the analysis.
RAI-11.2:
State whether the assumed times for operators to perform various tasks, such as 32 minutes for PEO-2 to open 2-CH-192 (Attachment 1, Page 36, Table 7), are reasonable. For instance, provide a justification for assuming that it will take PEO-2 32 minutes from the time they are directed to open 2-CH-192 to travel to and open the valve and then confirm that it is open.
January 13, 2012 Mr. David A. Heacock President and Chief Nuclear Officer Dominion Nuclear Connecticut, Inc.
Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711
SUBJECT:
MILLSTONE POWER STATION, UNIT NO.2 - REQUEST FOR ADDITIONAL INFORMATION REGARDING REQUEST FOR EXMEPTION FROM TITLE 10 OF THE CODE OF FEDERAL REGULA TlONS, PART 50, APPENDIX R, SECTION III.G, "FIRE PROTECTION OF SAFE SHUTDOWN CAPABILITY" (TAC NO. ME6693)
Dear Mr. Heacock:
By letter dated June 30, 2011,1 Dominion Nuclear Connecticut, Inc., submitted a request for exemption from Title 10 of the Code of Federal Regulations, Part 50, Appendix R,Section III.G, "Fire Protection of Safe Shutdown Capability" for Millstone Power Station, Unit No.2 (MPS2).
The proposed exemption would allow the use of operator manual actions in lieu of the requirements of 10 CFR 50, Appendix R, Section III.G.2. To complete its review, the Nuclear Regulatory Commission staff requests responses to the enclosed questions.
The draft questions were sent to Mr. William Bartron, of your staff, to ensure that the questions were understandable, the regulatory basis for the questions was clear, and to determine if the information was previously docketed. On January 6, 2012, Mr. William Bartron agreed that you would provide a response by February 29, 2012.
If you have any questions regarding this matter, please contact me at 301-415-1603.
Sincerely, Ira!
Carleen J. Sanders, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-336
Enclosure:
As stated 1 Agencywide Documents Access Management System Accession No. ML11188A213 cc w/encl: Distribution via Listserv RidsAcrsAcnw_MailCTR Resource RidsNrrDorlDpr Resource RidsNrrDorlLpl1-2 Resource RidsNrrAfpb Resource RidsNrrLAABalder Resource RidsNrrPMMillstone Resource RidsOgcRp Resource RidsRgn1 MailCenter Resource Branch Reading PUBLIC Adams Accession No.: ML113120050
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I OFFICE LPL 1-2/PM LPL1-2/LA AFPB LPL1-2/BC NAME CSanders ABaxter J. Robinson for A. Klein*
HChernoff DATE 01/05/2012 12/07/2011 10/2512011 01/03/2012 OffiCial Record Copy