ML13070A213
| ML13070A213 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 03/29/2013 |
| From: | Balwant Singal Plant Licensing Branch IV |
| To: | Office of Nuclear Reactor Regulation |
| Singal B | |
| References | |
| TAC MF0578, TAC MF0579 | |
| Download: ML13070A213 (7) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 March 29, 2013 LICENSEE: STP Nuclear Operating Company FACILITY: South Texas Project, Units 1 and 2
SUBJECT:
SUMMARY
OF MARCH 5, 2013, PRE-LICENSING CONFERENCE CALL PUBLIC MEETING WITH STP NUCLEAR OPERATING COMPANY TO DISCUSS THE PROPOSED LICENSE AMENDMENT REQUEST FOR APPROVAL OF THE REVISED FIRE PROTECTION PROGRAM RELATED TO THE ALTERNATE SHUTDOWN CAPABILITY DOCUMENTED IN THE FIRE HAZARDS ANALYSIS (TAC NOS, MF0578 AND MF0579)
On March 5,2013, a conference call public meeting was held between the U,S, Nuclear Regulatory Commission (NRC), and representatives of STP Nuclear Operating Company (STPNOC, the licensee) at NRC Headquarters, Rockville, Maryland. The meeting notice and agenda, dated February 22, 2013, is located in the Agencywide Documents Access and Management System (ADAMS) at Accession No, ML13046A065. The purpose of the meeting was to discuss the proposed license amendment request (LAR) for approval of the revised fire protection program related to the alternate shutdown capability documented in the fire hazards analYSis for South Texas Project (STP), Units 1 and 2.
A list of meeting attendees is provided as an Enclosure 1 to this meeting summary, Discussion Topics The discussion included an overview of the proposed LAR for STP, Units 1 and 2, as follows:
- Purpose
- Proposed licensing Action and Operator Actions
- Impacted Regulatory Requirements
- Impact of the Proposed Request on Operating licenses for STP, Units 1 and 2
- Technical and Analytical Basis for the Proposed Licensing Action
- Summary of the Results for limiting Case Analysis Performed in Support of the Proposed Action, including Fire Modeling of the Main Control Room
- Submittal Schedule
- Summary and Conclusions A copy of the meeting materials/handouts dated February 20, 2013, is located at ADAMS Accession No. ML13051A855. The licensee provided an additional slide for Control Room Control Panel Switcb Orientation on the day of the meeting. A copy of this slide is provided in ,
-2 Results of Discussions
- The licensee clarified that the proposed application will be based on a deterministic approach.
- The licensee made a reference to Title 10 of the Code of Federal Regulations (10 CFR),
paragraph 50.48(e) on slide 8 of the presentation. The NRC staff stated that 10 CFR 50.48(e) has been deleted and should not be referenced as a regulatory requirement in the proposed submittal.
- On slide 15, the licensee stated "Operator will be pre-alerted because actions are not initiated until a fire occurs and the decision is made to trip the reactor. The NRC staff II was concerned that if the fire causes a plant trip, there may not be sufficient time to pre alert the operators for performing the operator actions from the control room. The licensee stated that there are detection systems installed that will pre-alert the operator about the control room fire. The licensee stated that these systems will be discussed in the proposed submittal.
- On slide 17, titled, "Design features," the licensee mentioned robust safety train circuit separation. The NRC staff requested the licensee to provide more details about routing of the cables in the proposed submittal to ensure safety train separation.
- The NRC staff questioned if loss-of-offsite power event was considered in conjunction with the most limiting fire scenario. The licensee stated that based on its analysis, the worst-case scenario is offsite power available in conjunction with the most limiting fire scenario. The licensee agreed to clearly discuss it in its proposed submittal.
- The NRC staff suggested that the licensee should address the adequacy of use of RETRAN-3D (computer code used to perform transient thermal-hydraulic analysis of light water reactors) to show that the natural circulation (based on single and two-phase flow) and reflux boiling can be maintained following a loss-of-offsite power event. It should include a discussion of the data used for the RETRAN model comparison, the treatment of the measurement uncertainties of the data associated with the initial conditions and instrumentation data, and the results of the RETRAN code bench marked with the applicable test data related to the two-phase flow natural circulation cooldown and reflux boiling phenomenon. As an example, comparisons could be made to NRC approved methodology that relies on RETRAN and any differences could be identified and discussed.
- On slide 22, the licensee discussed the scenario when no credit is taken for any of the proposed operator actions. The licensee stated that the most limiting case will be a stuck open pressurizer power-operated relief valve (PORV). The licensee made an assumption that the operator can terminate the event by securing the pressurizer PORV in 10 minutes from the alternate control station. The licensee was requested to explain the scenario in detail, including the circuit protection scheme in the proposed submittal.
The licensee was also requested to confirm if the PORV would pass liquid water during the postulated event.
-3
- For the scenario when no credit is taken for the proposed operator actions, the licensee confirmed that no credit has been taken for any additional operator action from the control room. It was suggested that the licensee state it clearly in the proposed submittal.
- On slide 35, the licensee stated that it intends to use Consolidated Fire Growth and Smoke Transport Model (CFAST) for modeling the control room fire. The NRC staff suggested that the proposed submittal should include verification and validation for the use of CFAST model and was advised to refer to NUREG-1824, Volume 5, "Verification and Validation of Selected Fire Models for Nuclear Power Plant Applications," (ADAMS Accession No. ML071730527) for details.
- The NRC staff was concerned that licensee has not discussed the impact of hot shorts inside the control room as a result of the fire in the control room (
Reference:
Information Notice 92-18, "Potential for Loss of Remote Shutdown Capability During a Control Room Fire," February 28, 1992 (ADAMS Accession No. ML031200481) and requested the licensee to address the impact of hot shorts in the proposed submittal.
-4 No Public Meeting Feedback Forms were received for this meeting.
Please direct any inquiries to me at (301) 415-3016, or balwant.singal@nrc.gov.
Sincerely, D __~ v--T1t:.2J, v0 ~
Balwant K. Singal, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-498 and 50-499
Enclosures:
- 1. List of Attendees
- 2. Copy of Additional Slide cc w/encl: Distribution via Listserv
LIST OF ATTENDEES MARCH 5, 2013, CONFERENCE CALL PUBLIC MEETING WITH STP NUCLEAR OPERATING COMPANY REGARDING PROPOSED LICENSE AMENDMENT REQUEST FOR APPROVAL OF REVISED FIRE PROTECTION PROGRAM RELATED TO THE ALTERNATE SHUTDOWN CAPABILITY SOUTH TEXAS PROJECT, UNITS 1 AND 2 DOCKET NOS. 50-498 AND 50-499 NAME TITLE ORGANIZATION Ken T applett* Licensing Engineer !STP Nuclear Operating Company I i
(STPNOC) I Roland Dunn* Manager, Nuclear Fuel and Analysis STPNOC Frank Cox* Safe Shutdown Supervising 'STPNOC
. Engineer Charles Albury* Thermal Hydraulic Analysis STPNOC Supervisor Michael Murray* Manager, Regulatory Affairs STPNOC Donald Rohan* Operations Procedures STPNOC Mike Berg* - STPNOC
- Coley Chappel* - STPNOC Duane Gore* - STPNOC i Balwant K. Singal Senior Project Manager U.S. Nuclear Regulatory Commission (NRC) I Harry Barrett Senior Fire Protection Engineer NRC I Daniel Frumkin Team Leader, Fire Protection NRC I I
Branch Carmen Franklin Human Factor Engineer NRC Ben Parks* Reactor Systems Engineer NRC
- Undine Shoop* Chief, Health Physics and Human , NRC Performance Branch I Summer B. Sun Senior Reactor Engineer NRC
- Participated via phone Enclosure 1
Control Room Control Panel Switch Orientation ZCP_ ZCP_ ZCP....
CONTROL ROOM U;Gl:1C)
- 1. REJOCTtIR TRIP 5111 TCW
- 2. MAIN STUM ISOLATION SWITCW
- 3. _SQlRIZfiR P()RV a.OCK Y.liLVE S1fITO$ (TWOI
". RCP TRIP S1fITO$ (FOUR.
- 5. FUOWATER ISOLATION S1fITCW (FOUR' O. STMTUP FEEOWATER _ PU.L-TCH.OCK S1fITCW
- 7. LET_ ISOLATION SIIITCHES (TWO)
I!. CHMGIMC _ PU.L-TO-LOCK SWITCHES (TWO' E!
§I NOTE EI §I .IiLL S1fITCWES _ ON fElICHBOMO PART OF PANEL I!X(%PT S1fITCW[S 3
- 7 WHICH _ ON YVlTlCiIL SECT ION OF PANEL.
~
SOUTH TEXAS PROJECT ccoo_ _ ccoo_
UNITS 1 .. 2_ _
_ ,TCH OIlIOtTAT ION F'1~1 REvISION
- Back Up Slide 1 - South Texas Project Enclosure 2
- 3 No Public Meeting Feedback Forms were received for this meeting.
Please direct any inquiries to me at (301) 415-3016, or balwant.singal@nrc.gov.
Sincerely, IRAJ Balwant K. Singal, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor licensing Office of Nuclear Reactor Regulation Docket Nos. 50-498 and 50-499
Enclosures:
- 1. List of Attendees
- 2. Copy of Additional Slide cc w/encl: Distribution via Listserv DISTRIBUTION:
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!DATE ! 3/15/13 3/13/13 3/20/13 3/26/13 I OFFICE NRR/DRAJAFPB/BC NRR/LPL4/BC NRR/LPL4/PM MMarkley (JPolickoski NAME AKlein ! for) BSingal DATE 3/19/13 ! 3/29/13 3/29/13 OFFICIAL RECORD COPY