ML070180137
| ML070180137 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 01/29/2007 |
| From: | Williams J NRC/NRR/ADRO/DORL/LPLIII-2 |
| To: | Crane C Exelon Generation Co |
| Williams J, NRR/DLPM/LPD1, 415-1470 | |
| References | |
| GL-03-001, TAC MB9799, TAC MB9800 | |
| Download: ML070180137 (4) | |
Text
January 29, 2007 Mr. Christopher M. Crane President and Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
DRESDEN NUCLEAR POWER STATION UNITS 2 AND 3, RESPONSES TO GENERIC LETTER 2003-01, ?CONTROL ROOM HABITABILITY (TAC NOS.
MB9799 AND MB9800)
Dear Mr. Crane:
The Nuclear Regulatory Commission (NRC) acknowledges the receipt of your responses to Generic Letter (GL) 2003-01, Control Room Habitability dated December 9, 2003 (Agencywide Document Access and Management System (ADAMS) Accession No. ML033560302); September 30, 2004 (ADAMS accession no. ML042740704);
November 29, 2004 (ADAMS Accession No. ML043420211); and July 11, 2005 (ADAMS Accession No. ML051920406) for the Dresden Nuclear Power Station, Units 2 and 3 (Dresden).
This letter provides a status of your responses and describes any actions that may be necessary to consider your responses to GL 2003-01 complete.
The GL 2003-01 requested that you confirm that your control rooms meet their design bases (e.g., General Design Criteria (GDC) 1, 3, 4, 5, and 19, draft GDC, or principal design criteria),
with special attention to: (1) determination of the most limiting unfiltered and/or filtered inleakage into the control room and comparison to values used in your design bases for meeting control room operator dose limits from accidents (GL 2003-01, Item 1a);
(2) determination that the most limiting unfiltered inleakage is incorporated into your hazardous chemical assessments; and, (3) determination that reactor control capability is maintained in the control room or at the alternate shutdown location in the event of smoke (GL 2003-01, Item 1b).
The GL 2003-01 further requested information on any compensatory measures in use to demonstrate control room habitability, and plans to retire them (GL 2003-01, Item 2).
You reported the results of the American Society for Testing and Materials (ASTM) E741 tracer gas tests for the Dresden control room which is common for the units and pressurized for accident mitigation. The tracer gas tests were performed with the heating, ventilation, and air conditioning (HVAC) system(s) in emergency mode. The test results in comparison with the design basis requirements are as follows:
For Dresden you determined that the maximum tested value for inleakage into the Dresden control room envelope (CRE) was 162 (+/- 91) cubic feet per minute (cfm),
which is less than the value of 263 cfm assumed in the design basis radiological
C. Crane analyses for control room habitability.
On October 10, 2002, you submitted a license amendment request (LAR) to adopt alternative source term (AST) methodology. On September 11, 2006, license amendments Nos. 221 and 212 were issued changing the value assumed in the Dresden radiological consequence analyses from 263 cfm to 400 cfm which is still more than the maximum tested value for inleakage into the CRE.
You indicated that based on your assessment of offsite and onsite hazardous chemicals, unfiltered air in-leakage testing of toxic gas isolation mode is not required. You also indicated that reactor control capability is maintained from either the control room or the alternate shutdown panel in the event of smoke.
The GL 2003-01 further requested that you assess your technical specifications (TS) to determine if they verify the integrity of the CRE, including ongoing verification of the inleakage assumed in the design-basis analysis for control room habitability in light of the demonstrated inadequacy of a delta () P measurement to alone provide such verification (GL 2003-01, Item 1c). In your July 11, 2005, response you withdrew your previous LAR for administrative controls and indicated that you would evaluate your submittal with respect to the elements contained in the Technical Specification Task Force Traveler No. 448, (TSTF-448) ?Control Room Habitability and resubmit a proposed license amendment request based on the evaluation. As permitted by the GL 2003-01, you provided a schedule for revising the surveillance requirement in the TS to reference an acceptable surveillance methodology. Your schedule for resubmitting the LAR is within 90 days of NRC approval of TSTF-448.
The information you provided also supported the fact that there are no compensatory measures needed to be in place to demonstrate control room habitability. The information you provided also supported the conclusion that Dresden satisfies the intent of the GDC regarding control room habitability.
Your commitment to submit a proposed LAR based on TSTF-448, following our formal review and approval, is acceptable for purposes of closing out your responses to GL 2003-01. The NRC staff will monitor submission of the proposed LAR and interact with you as necessary during the amendment process.
If you have any questions regarding this correspondence, please contact me.
Sincerely,
/RA/
Joseph F. Williams, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-237 and 50-249 cc: See next page
C. Crane On October 10, 2002, you submitted a license amendment request (LAR) to adopt alternative source term (AST) methodology. On September 11, 2006, license amendments Nos. 221 and 212 were issued changing the value assumed in the Dresden radiological consequence analyses from 263 cfm to 400 cfm which is still more than the maximum tested value for inleakage into the CRE.
You indicated that based on your assessment of offsite and onsite hazardous chemicals, unfiltered air in-leakage testing of toxic gas isolation mode is not required. You also indicated that reactor control capability is maintained from either the control room or the alternate shutdown panel in the event of smoke.
The GL 2003-01 further requested that you assess your technical specifications (TS) to determine if they verify the integrity of the CRE, including ongoing verification of the inleakage assumed in the design-basis analysis for control room habitability in light of the demonstrated inadequacy of a delta () P measurement to alone provide such verification (GL 2003-01, Item 1c). In your July 11, 2005, response you withdrew your previous LAR for administrative controls and indicated that you would evaluate your submittal with respect to the elements contained in the Technical Specification Task Force Traveler No. 448, (TSTF-448) ?Control Room Habitability and resubmit a proposed license amendment request based on the evaluation. As permitted by the GL 2003-01, you provided a schedule for revising the surveillance requirement in the TS to reference an acceptable surveillance methodology. Your schedule for resubmitting the LAR is within 90 days of NRC approval of TSTF-448.
The information you provided also supported the fact that there are no compensatory measures needed to be in place to demonstrate control room habitability. The information you provided also supported the conclusion that Dresden satisfies the intent of the GDC regarding control room habitability.
Your commitment to submit a proposed LAR based on TSTF-448, following our formal review and approval, is acceptable for purposes of closing out your responses to GL 2003-01. The NRC staff will monitor submission of the proposed LAR and interact with you as necessary during the amendment process.
If you have any questions regarding this correspondence, please contact me.
Sincerely,
/RA/
Joseph F. Williams, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-237 and 50-249 cc: See next page DISTRIBUTION:
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Dresden Nuclear Power Units 2 and 3 cc:
Site Vice President - Dresden Exelon Generation Company, LLC 6500 N. Dresden Road Morris, IL 60450-9765 Plant Manager - Dresden Nuclear Power Station Exelon Generation Company, LLC 6500 N. Dresden Road Morris, IL 60450-9765 Manager Regulatory Assurance - Dresden Exelon Generation Company, LLC 6500 N. Dresden Road Morris, IL 60450-9765 U.S. Nuclear Regulatory Commission Dresden Resident Inspectors Office 6500 N. Dresden Road Morris, IL 60450-9766 Chairman Grundy County Board Administration Building 1320 Union Street Morris, IL 60450 Regional Administrator, Region III U.S. Nuclear Regulatory Commission Suite 210 2443 Warrenville Road Lisle, IL 60532-4351 Illinois Emergency Management Agency Division of Disaster Assistance &
Preparedness 110 East Adams Street Springfield, IL 62701-1109 Document Control Desk - Licensing Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Senior Vice President - Midwest Operations Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Director - Licensing & Regulatory Affairs Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Vice President - Regulatory & Legal Affairs Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Assistant General Counsel Exelon Generation Company, LLC 200 Exelon Way Kennett Square, PA 19348 Manager Licensing - Dresden Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555