ML092640371
| ML092640371 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 09/04/2009 |
| From: | Thadani M Plant Licensing Branch IV |
| To: | Harrison A, Taplett K South Texas |
| Thadani, M C, NRR/DORL/LP4, 415-1476 | |
| References | |
| TAC ME0824, TAC ME0825, TAC ME1389, TAC ME1390 | |
| Download: ML092640371 (6) | |
Text
From:
Thadani, Mohan Sent:
Friday, September 04, 2009 11:28 AM To:
Taplett, Kenneth; Harrison, Albon
Subject:
REQUEST FOR ADDITIONAL INFORMATION FIRE AREAS 27 AND 31 (TAC NOS.
ME0824, ME0825, ME1389 AND ME1390)
Wayne/Ken:
By letters dated February 3, 2009 (Agencywide Documents Access and Management System (ADAMS), Accession No. ML090410486,) and March 3, 2009 (ADAMS Accession No. ML090680781) for the South Texas Project (STP) Units 1 and 2, STP Nuclear Operating Company (STPNOC) requested Nuclear Regulatory Commission (NRC) amendments from certain requirements of Fire Protection Program, as documented in the STP Fire Hazards Analysis Report, and related to Title 10 of the Code of Federal Regulations Part 50, Appendix R,Section III.G.2 (III.G.2), for operator manual actions in lieu of meeting the circuit separation and protection requirements similar to those contained in III.G.2, for Fire Areas 27 and 31.
The NRC staff has reviewed the information provided by STPNOC and determined that additional information is needed to complete our review. Our request for additional information is outlined below. Please note that our review effort on these tasks (TAC Nos. ME0824, ME0825, ME1389 and ME1390) is ongoing. Please respond to this request within 45 days from the date of this email. If you are unable to respond by the requested date, please advice at your earliest convenience.
Mohan C Thadani Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation (301) 415-1476 Mohan.Thadani@nrc.gov REQUEST FOR ADDITIONAL INFORMATION ON THE LICENSE AMENDMENT REQUESTS FOR DEVIATION FROM FIRE PROTECTION PROGRAM REQUIREMENTS (FIRE AREAS 27 AND 31) AT SOUTH TEXAS PROJECT UNITS 1 AND 2 (TAC NOS. ME0824, ME0825, ME1389 AND ME1390)
By letters dated February 3, 2009, License Amendment Request for Deviation from Fire Protection Program Requirements [Fire Area 31] (ML090410486), and March 3, 2009, License Amendment Request for Deviation from Fire Protection Program Requirements (Fire Area 27)
(ML090680781), STP Nuclear Operating Company (STPNOC) requested license amendments for the South Texas Project (STP) Units 1 and 2 from certain technical requirements related to Title 10 of the Code of Federal Regulations (CFR) Part 50, Appendix R,Section III.G.2 (III.G.2),
as documented in the STP Fire Hazards Analysis Report, for the use of operator manual actions (OMAs) in lieu of meeting the circuit separation and protection requirements contained in III.G.2 for Fire Areas 27 and 31.
RAI-01 Circumstances for Review
Sections 1.0 and 2.0 of the requests contain descriptions of the proposed operator manual actions and deviations from the Fire Protection Program but do not contain a discussion of why STP is unable to meet the requirements of III.G.2 and why a deviation from the Fire Protection Program requirements is necessary.
Provide a justification of the circumstances that warrant the consideration of these license Amendments. Include a technical justification of how the proposed changes affect safe shut down capabilities and how the proposed means of compliance are effective in mitigating the affects of changes.
RAI-02 Regulatory Deficiency Section 2.0 of the requests provides background regarding the change but does not state, specifically, which criteria of III.G.2 are not met.
Provide a detailed description of the deficiencies that exist with regard to fire detection, suppression, intervening combustibles and spatial separation and explain how the deficiencies are mitigated with other forms of defense-in-depth measures. For example, if the 20-ft spatial separation between redundant equipment trains is not provided, provide a description of the separation that is provided and a justification for how the established level of safety and protection is maintained.
The licensees response should also include a technical explanation to justify how the proposed methods will result in a level of protection that is consistent with that intended by III.G.2. For example, demonstrate that defense-in-depth is provided such that operators are able to safely and reliably shut down the plant from the control room. Note that it is the Nuclear Regulatory Commission (NRC) staff's position that operator manual actions alone, regardless of their feasibility and reliability, do not meet the underlying purpose of the rule without specific consideration of the overall defense-in-depth methodology in place in a particular fire area.
RAI-03 Ensuring That One of the Redundant Trains Is Free of Fire Damage Criterion 4 of Section 3.0 of the February 3, 2009, request and Criterion 4 of Section 3.3 of the March 3, 2009, request state that the STP analysis demonstrates that at least one path of safe shutdown equipment is maintained free from a fire. Criterion 2 of Sections 3.2 and 3.3 of the March 3, 2009 request, and Criterion 2 of Section 3.0 of the February 3, 2009 request state that the analysis performed by STP assumes that all systems and components in the fire area are lost due to fire.
These statements are contradictory and should be clarified. If redundant equipment is co-located in a fire area and all of the equipment in that fire area is assumed lost during a fire event, the resulting condition would be inconsistent with III.G.2, which states that measures must be taken to ensure that one of the redundant trains remains free of fire damage.
Furthermore, the use of OMAs, in lieu of the three options provided in III.G.2, is not explicitly included as a means of compliance with III.G.2.
Clarify the statements made in the requests about whether redundant trains remain free of fire damage during a fire event and provide a technical justification to support the assumptions made in the analysis.
RAI-04 Other Evaluations
Fire areas may have other license amendments or engineering evaluations that affect fire protection systems or safe shutdown capabilities.
Provide a discussion of any other amendments or evaluations that impact this request in any way and a justification for why such additional impact in conjunction with the proposed changes should be considered acceptable.
RAI-05 Standards and Listings for Systems and Barriers Section 3.0 of the requests states that fire protection features are installed in the fire areas containing the redundant equipment. However, the requests do not state whether the features have been designed and installed in accordance with recognized design standards.
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 used. In addition, 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. Also, provide a technical justification for any non-rated fire protection assemblies. For example:
Fire Area (FA) 27 is noted as having ionization smoke detectors installed throughout the area.
State whether the detectors have been installed and maintained in accordance with a particular design standard or basis, e.g. National Fire Protection Association 72: National Fire Alarm Code, 1985 Edition.
Section 3.1 of the March 3, 2009, request states that the fire barriers that enclose Fire Zone Z127 do not contain 3-hour rated doors. No description is provided for the water-tight door in Fire Zone Z109.
Fire Zone Z139 is noted as having an automatic wet pipe sprinkler system installed over areas of concentrated cabling. State whether the sprinklers have been installed and maintained in accordance with a particular design standard or basis, e.g. National Fire Protection Association 13: Standard for the Installation of Sprinkler Systems, 1985 Edition.
RAI-06 Time and Sequence Assumptions The requests lack a detailed description of the series of events that may occur prior to initiating the Operator Manual Action procedures.
Describe the circumstances and assumptions needed to enter the OMA procedure. For example, describe the amount of time, and the technical basis, that has been assumed for detection and assessment of a postulated fire. Additionally, provide an analysis and a technical justification to evaluate scenarios where components fail, or damage occurs, before a fire has been detected.
RAI-07 Operator Qualification The requests make reference to the licensed operator re-qualification program. Provide a description of the portion of the program that would qualify operators with regard to the diagnosis of fires and their potential threat to components.
RAI-08 Fire Area of Origin Re-entry Section 3.3 of the March 3, 2009, request states that operators are required to re-enter FA 27 to perform an action following a fire event. Analyses often assume loss of all equipment in the fire area of origin. In fact, this assumption is made at STP according to Criterion 2 of Sections 3.2 and 3.3 of the same request.
Justify why the assumption that all equipment located in the fire area of origin is lost during a fire does not apply to all postulated fire events in FA 27. Additionally, provide critical details and/or assumptions of the analysis that demonstrates that the required safe shut down equipment and/or component located within the area is maintained free of fire damage and remains operable following the fire event.
RAI-09 Smoke Evacuation Procedures and Tenability Criterion 3 in Section 3.3 of the March 3, 2009, request states that the manual actions in FA 27 will require the use of personnel protection equipment and may require the use of self-contained breathing apparatus (SCBA). Additionally, Criterion 3 of Section 3.3 of the March 3, 2009, request states that smoke is removed from the fire area and directed up stairwells in a manner that should not impede the path for performing the manual action.
Provide critical details and/or assumptions of the analysis that demonstrates that the path that operators are expected to traverse, as well as the space where control valve CV-MOV-8377B is located, remain tenable for operators to enter the fire zone following a fire event and fire brigade operations including scenarios requiring the use of SCBA.
State whether operator use of SCBA is required to complete the OMAs. If so, demonstrate that operators tasked with performing the manual actions arrive at the fire zone donned in SCBA to perform the actions.
Describe the basis for the practice of removing smoke by directing it into stairwells and substantiate the claim that this practice would not adversely impact the performance of the operator manual actions.
RAI-10 Fire Severity, Duration and Proximity to Redundant Equipment The March 3, 2009, request makes various references to the fire severity that is anticipated for Fire Zone Z127 ranging from 0.33 minutes (Section 3.3) to 30 minutes (Table 7-1) and Criterion 1 of Section 3.3 of the March 3, 2009, request states that the limiting zone fire duration is analyzed to be less than 25 minutes. Table 7-1 indicates that all but one of the fire zones in FA 27 have a permissible fire loading but the associated analysis does not describe the location or distribution of the loading.
Address this contradiction and provide the correct fire loading values and assumptions and confirm which value was used for the fire severity analysis in FA 27.
Describe where the combustible fuel loading occurs within the fire zones, e.g. in close proximity to the redundant equipment, and describe what controls are in place to limit the storage of transient materials in the fire zone.
RAI-11 Initiation of Procedures and Communications Criterion 6 of Section 3.3 states that valve CV-MOV-8377B is located in a communications dead zone. Additionally, the performance times noted in Criterion 2 of Section 3.2 of the March 3, 2009, request and Criterion 2 of Section 3.0 of the February 3, 2009, request assume that operators initiate the OMA procedure from their normal watch station.
Describe how a delay to initiate the OMA procedures as a result of communication challenges, absent/preoccupied operators or otherwise, has been accounted for in the assumed timelines.
Describe to what extent operators tasked with completing the manual action would need to communicate with the control room and specifically how this would be accomplished.
State whether other communication dead zones exist and, if so, describe how instances where operators may be stationed in such locations or touring the plant at the time the OMA procedure is initiated is accounted for in the analysis. Also describe how the potential time required for the operators to return to their duty station has been accounted for in the analysis.
E-mail Properties Mail Envelope Properties ()
Subject:
REQUEST FOR ADDITIONAL INFORMATION FIRE AREAS 27 AND 31 (TAC NOS. ME0824, ME0825, ME1389 AND ME1390)
Sent Date: 9/4/2009 9:04:47 AM Received Date: 9/4/2009 11:28:00 AM From: Thadani, Mohan Created By: Mohan.Thadani@nrc.gov Recipients:
kjtaplett@STPEGS.COM (Taplett, Kenneth)
Tracking Status: None awharrison@STPEGS.COM (Harrison, Albon)
Tracking Status: None Post Office:
Files Size Date & Time MESSAGE 27668 9/4/2009 Options Expiration Date:
Priority: olImportanceNormal ReplyRequested: False Return Notification: False
Sensitivity: olNormal Recipients received: