ML071640204
| ML071640204 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities  |
| Issue date: | 06/11/2007 |
| From: | Satorius M Division Reactor Projects III |
| To: | Crane C Exelon Generation Co, Exelon Nuclear |
| References | |
| Download: ML071640204 (5) | |
Text
June 11, 2007 Mr. Christopher M. Crane President and Chief Nuclear Officer Exelon Nuclear Exelon Generation Company, LLC Quad Cities Nuclear Power Station and Dresden Nuclear Power Station 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
REQUEST FOR ACCEPTANCE FOR CONTINUOUS EXTENDED POWER UPRATE OPERATION
Dear Mr. Crane:
This refers to Exelon Generation Company, LLC (EGC), Letter RS-07-053, dated April 20, 2007, (Agencywide Document Access and Management System (ADAMS)
Accession No. ML071100477), which requested Nuclear Regulatory Commission (NRC) acceptance for continuous operation of the Quad Cites Nuclear Power Station Units 1 and 2 at Extended Power Uprate (EPU) power levels up to and including the full licensed thermal power level of 2957 megawatts-thermal. Exelon Generation Companys April 20, 2007, letter referenced the March 22, 2007, meeting between EGC and NRC management to discuss the results and conclusions of evaluations and plant modifications performed to support long-term EPU operation of the Quad Cities units and the several meetings and letters that preceded the March 22 meeting. Exelon Generation Companys April 20, 2007, letter also provided the remaining commitments and inspection activities for Quad Cities and Dresden in Attachments 1 and 2.
In EGCs presentation on March 22, 2007, your staff described the replacement steam dryers and upgraded electromatic relief valve (ERV) actuators as designed to withstand the Quad Cities Nuclear Power Station bounding vibration and acoustic loads prior to the vibration source reduction effort. In addition, EGC installed acoustic side branch (ASB) modifications on both Quad Cities units to reduce the acoustic and vibrational loading and the ASBs have been successful in reducing those loads to below the pre-EPU levels. The NRC has monitored EGCs efforts to strengthen the steam dryers and ERV actuators and EGCs efforts to reduce the acoustic loading and resulting vibrations through the installation of the ASB modifications.
The NRC has reviewed the information your staff presented in the March 22, 2007, meeting.
In addition, our inspectors monitored the condition of the steam dryer, the ERV actuators, four main steam safety valve ASBs, and two ERV ASBs during the recent Unit 1 refueling outage.
Unit 1 had operated for approximately one year at EPU power level following the installation of the ASB modifications in 2006. All of these components were found to be in satisfactory condition with only minimal wear noted.
C. Crane Accordingly, we conclude that the combination of ASB modifications and strengthened steam dryers and ERV actuators has effectively addressed the vibration-caused degraded conditions experienced by these components sufficient to support continuous operation at EPU power levels. The NRC has no objection to continuous operation of the Quad Cites Nuclear Power Station Units 1 and 2 at EPU power levels up to and including the full licensed thermal power level of 2957 megawatts-thermal. For Quad Cities and Dresden, we expect that EGC will continue to fulfill the remaining commitments and inspection activities as described in Attachments 1 and 2, respectively, to EGCs April 20, 2007, letter. Should EGC decide that changes to the commitments and activities described in these attachments are necessary, please contact the NRC Region III Branch Chief responsible for Quad Cities and Dresden.
In addition, we note that both Quad Cities units have continued to experience cracking in the main steam drain line restraints which were installed following initial ascension to EPU power levels. While these restraints are not safety-related components and were not the primary focus of previous discussions on EPU-related vibrational damage, EGC should continue efforts to identify, understand, and resolve the source of cracking in these restraints.
In accordance with Title 10 of the Code of Federal Regulations, Section 2.390 of the NRCs Rules of Practice, a copy of this letter, and any responses you provide will be made available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records System (PARS) component of NRCs document system (ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Should you have any questions regarding this matter, please contact the Region III Branch Chief for Quad Cities and Dresden, Mr. Mark Ring, at (630) 829-9703.
Sincerely,
/RA/
Mark A. Satorius, Director Division of Reactor Projects Docket Nos. 50-237; 50-249; 50-254; 50-265 License Nos. DPR-19; DRP-25; DPR-29; DPR-30 DISTRIBUTION:
See next page
C. Crane Accordingly, we conclude that the combination of ASB modifications and strengthened steam dryers and ERV actuators has effectively addressed the vibration-caused degraded conditions experienced by these components sufficient to support continuous operation at EPU power levels. The NRC has no objection to continuous operation of the Quad Cites Nuclear Power Station Units 1 and 2 at EPU power levels up to and including the full licensed thermal power level of 2957 megawatts-thermal. For Quad Cities and Dresden, we expect that EGC will continue to fulfill the remaining commitments and inspection activities as described in Attachments 1 and 2, respectively, to EGCs April 20, 2007, letter. Should EGC decide that changes to the commitments and activities described in these attachments are necessary, please contact the NRC Region III Branch Chief responsible for Quad Cities and Dresden.
In addition, we note that both Quad Cities units have continued to experience cracking in the main steam drain line restraints which were installed following initial ascension to EPU power levels. While these restraints are not safety-related components and were not the primary focus of previous discussions on EPU-related vibrational damage, EGC should continue efforts to identify, understand, and resolve the source of cracking in these restraints.
In accordance with Title 10 of the Code of Federal Regulations, Section 2.390 of the NRCs Rules of Practice, a copy of this letter, and any responses you provide will be made available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records System (PARS) component of NRCs document system (ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Should you have any questions regarding this matter, please contact the Region III Branch Chief for Quad Cities and Dresden, Mr. Mark Ring, at (630) 829-9703.
Sincerely, Mark A. Satorius, Director Division of Reactor Projects Docket Nos. 50-237; 50-249; 50-254; 50-265 License Nos. DPR-19; DRP-25; DPR-29; DPR-30 DISTRIBUTION:
See next page DOCUMENT NAME:C:\\FileNet\\ML071640204.wpd G Publicly Available G Non-Publicly Available G Sensitive G Non-Sensitive To receive a copy of this document, indicate in the concurrence box "C" = Copy without attach/encl "E" = Copy with attach/encl "N" = No copy OFFICE RIII RIII NRR RIII NAME MRing:dtp CPederson CHaney MSatorius DATE 06/08/07 06/11/07 06/11/07 06/11/07 OFFICIAL RECORD COPY Letter to Christopher M. Crane from Mark A. Satorius dated June 11, 2007
SUBJECT:
REQUEST FOR ACCEPTANCE FOR CONTINUOUS EXTENDED POWER UPRATE OPERATION cc:
Site Vice President - Quad Cities Nuclear Power Station Site Vice President - Dresden Nuclear Power Station Dresden Nuclear Power Station Plant Manager Quad Cities Nuclear Power Station Plant Manager Regulatory Assurance Manager - Quad Cities Regulatory Assurance Manager - Dresden Chief Operating Officer Senior Vice President - Nuclear Services Senior Vice President - Mid-West Regional Operating Group Vice President - Mid-West Operations Support Vice President - Licensing and Regulatory Affairs Director Licensing - Mid-West Regional Operating Group Manager Licensing - Dresden and Quad Cities Senior Counsel, Nuclear, Mid-West Regional Operating Group Document Control Desk - Licensing Vice President - Law and Regulatory Affairs Mid American Energy Company Assistant Attorney General Illinois Department of Nuclear Safety State Liaison Officer, State of Illinois State Liaison Officer, State of Iowa Chairman, Illinois Commerce Commission D. Tubbs, Manager of Nuclear MidAmerican Energy Company
Letter to Christopher M. Crane from Mark A. Satorius dated June 11, 2007
SUBJECT:
REQUEST FOR ACCEPTANCE FOR CONTINUOUS EXTENDED POWER UPRATE OPERATION DISTRIBUTION:
TEB RAG1 JFW1 CJP3 CXG1 MMT RidsNrrDirsIrib GEG KGO KKB DRPIII DRSIII PLB1 TXN