ML070930466
| ML070930466 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 05/24/2007 |
| From: | Thorpe-Kavanaugh M NRC/NRR/ADRO/DORL/LPLIII-2 |
| To: | Crane C Exelon Generation Co |
| Thorpe-kavanaugh NRR/DORL 415-5735 | |
| References | |
| GL-03-001, TAC MB9845, TAC MB9846 | |
| Download: ML070930466 (6) | |
Text
May 24, 2007 Mr. Christopher M. Crane President and Chief Nuclear Officer Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
CLOSURE OF QUAD CITIES NUCLEAR POWER STATION, UNITS 1 AND 2, RESPONSES TO GENERIC LETTER 2003-01, CONTROL ROOM HABITABILITY (TAC NOS. MB9845 AND MB9846)
Dear Mr. Crane:
This letter describes closure of Generic Letter (GL) 2003-01, Control Room Habitability for Exelon Generation Companys (EGCs) Quad Cities Nuclear Power Station, Units 1 and 2 (Quad Cities). The correspondences submitted by EGC in response to GL 2003-01 are listed in the enclosure.
GL 2003-01 requested that power reactor licensees confirm that control rooms meet their design bases (e.g., General Design Criterion (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 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 hazardous chemical assessments (GL 2003-01, Item 1b); 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). 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).
EGC reported the results of the American Society for Testing Materials, E741, Standard Test Method for Determining Air Change in a Single Zone by Means of a Tracer Gas Dilution tracer gas tests for the Quad Cities control room which is a common control room pressurized for accident mitigation.
In April of 1997, EGC determined that the tested value for inleakage into the control room envelope (CRE), was 297 cubic feet per minute (cfm) for Train A and 162 cfm for Train B.
The value for Train A was above the value of 260 cfm assumed in the design basis radiological dose analysis for control room habitability, while the value for Train B was below the value of 260 cfm assumed in the design basis radiological dose analyses control room habitability.
On September 11, 2006, license amendments 229 and 233 were issued for Quad Cities, to adopt alternative source term (AST) methodology by replacing the current accident source term described in Technical Information Document 14844 with an accident source term as prescribed in Title 10 to the Code of Federal Regulations, Section 50.67. Adoption of AST changed the value assumed in the radiological consequence dose analyses from 260 cfm to 400 cfm which when compared to the 1997 tracer gas test results, is more than the maximum tested value for both Train A and Train B.
In September of 2006, EGC determined that the tested value for inleakage into the CRE was 103 cfm for Train A and 80 cfm for Train B both of which are below the revised value of 400 cfm assumed in the design basis radiological dose analysis for control room habitability after adopting AST methodology.
EGC stated that while either train is capable of being used following a design basis accident, only Train B is credited to support the CRE, and only Train B is required operable to meet the technical specification (TS) operability requirements. EGC also stated that the Quad Cities TS Bases documents and site procedures specify the use of Train B during normal or emergency conditions, while Train A is limited to normal operation.
EGC also provided information that adequately supported a conclusion that the most limiting unfiltered in leakage into the CRE is incorporated into the hazardous chemical assessments, and that reactor control capability is maintained from either the control room or the alternate shutdown panel in the event of smoke.
GL 2003-01 further requested that licensees assess their TSs, to determine if the TSs 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 differential measurement to alone provide such verification (GL 2003-01, Item 1c). As permitted by GL 2003 -01, EGC provided a schedule for revising the surveillance requirement in the TS to reference an acceptable surveillance methodology. EGCs July 11, 2005, letter indicated that EGC will evaluate its submittal with respect to the elements contained in TS Task Force Traveler No. 448 (TSTF-448), Control Room Habitability, and resubmit a proposed license amendment based on the evaluation. This license amendment request (LAR) was submitted on April 12, 2007.
The information EGC provided also supports the fact that compensatory measures are not needed to be in place to demonstrate control room habitability. The information EGC provided also supported the conclusion that the units meet the intent of the draft GDC regarding control room habitability.
Based on the information discussed above, and EGCs LAR submittal of the April 12, 2007, the NRC concludes that EGCs response to GL 2003-01 is closed.
If you have any questions regarding this correspondence, please contact me.
Sincerely,
/RA/
Meghan Thorpe-Kavanaugh, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-254 & 50-265
Enclosure:
Table 1 cc w/encl: See next page Based on the information discussed above, and EGCs LAR submittal of the April 12, 2007, the NRC concludes that EGCs response to GL 2003-01 is closed.
If you have any questions regarding this correspondence, please contact me.
Sincerely,
/RA/
Meghan Thorpe-Kavanaugh, Project Manager Plant Licensing Branch III-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-254 & 50-265
Enclosure:
Table 1 cc w/encl: See next page DISTRIBUTION:
PUBLIC RidsNrrDorlLpl3-2 RidsRgn3MailCenter LPL3-2 R/F RidsNrrPMJRobinson MRing, Region III RidsNrrLAEWhitt RidsOgcRp RidsNrrDirsItsb RidsNrrPMJWilliams RidsAcrsAcnwMailCenter ADAMS Accession Number: ML070930466 NRR-106 OFFICE LPL3-2 LPL3-2/PM LPL3-2/LA PGCB/PM SCVB/BC LPL3-2/BC NAME MThorpe-Kavanaugh JWilliams EWhitt JRobinson RDennig RGibbs DATE 5/23/07 05 /17/07 05/23/07 05/18/07 05/21/07 5/24/07 OFFICIAL RECORD COPY
Quad Cities Nuclear Power Station Units 1 and 2 cc:
Site Vice President - Quad Cities Exelon Generation Company, LLC 22710 206th Avenue N.
Cordova, IL 61242-9740 Plant Manager - Quad Cities Nuclear Power Station Exelon Generation Company, LLC 22710 206th Avenue N.
Cordova, IL 61242-9740 Manager Regulatory Assurance - Quad Cities Exelon Generation Company, LLC 22710 206th Avenue N.
Cordova, IL 61242-9740 Quad Cities Resident Inspectors Office U.S. Nuclear Regulatory Commission 22712 206th Avenue N.
Cordova, IL 61242 David C. Tubbs MidAmerican Energy Company One River Center Place 106 E. Second, P.O. Box 4350 Davenport, IA 52808-4350 Vice President - Law and Regulatory Affairs MidAmerican Energy Company One River Center Place 106 E. Second Street P.O. Box 4350 Davenport, IA 52808 Chairman Rock Island County Board of Supervisors 1504 3rd Avenue Rock Island County Office Bldg.
Rock Island, IL 61201 Regional Administrator, Region III U.S. Nuclear Regulaory Commission Suite 210 4300 Winfield Road Warrenville, IL 60555 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 - Operations Support Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Director - Licensing and Regulatory Affairs Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Vice President - Regulatory Affairs Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Associate General Counsel Exelon Generation Company, LLC 4300 Winfield Road Warrenville, IL 60555 Manager Licensing - Dresden, Quad Cities and Clinton 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
Enclosure TABLE 1. Correspondence submitted by Exelon Generation Companys for Quad Cities Nuclear Power Station, Units 1 and 2 in Response to GL 2003-01.
Date of Letter ADAMS Accession No.
December 9, 2003 ML033560302 September 30, 2004 ML042740704 November 29, 2004 ML043420211 July 11, 2005 ML051920406 November 15, 2005 ML053200079 February 7, 2007 ML070390009 April 12, 2007 ML071090282