ML103230384
| ML103230384 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 11/23/2010 |
| From: | Ellen Brown Plant Licensing Branch III |
| To: | Pacilio M Exelon Nuclear |
| Billoch-Colon A, NRR/DORL, 301-415-3302 | |
| References | |
| TAC ME3354, TAC ME3355 | |
| Download: ML103230384 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Nove~ber 23, 2010 Mr. Michael J. Pacilio President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
DRESDEN NUCLEAR POWER STATION, UNITS 2 AND 3 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO A MODIFICATION THAT REPLACES THE TEMPERATURE-BASED ISOLATION INSTRUMENTATION (TAC NOS. ME3354 AND ME3355)
Dear Mr. Pacilio:
By letter to the Nuclear Regulatory Commission (NRC) dated February 4, 2010 (Agencywide Documents Access and Management System Accession (ADAMS) No. ML100470776), Exelon Generation Company, LLC submitted a request to revise Technical Specification (TS) 3.3.6.1, "Primary Containment Isolation Instrumentation," "Table 3.3.6.1-1, "Primary Containment Isolation Instrumentation," Function 6.a "Shutdown Cooling System Isolation, Recirculation Line Water Temperature - High," to enable implementation with reactor pressure-based isolation instrumentation, for the Dresden Nuclear Power Station, Units 2 and 3.
Subsequently, the NRC sent a Request for Additional Information (RAI) in a letter dated September 3,2010 (ADAMS No. ML102440366). Exelon responded to the RAI in a letter dated October 6, 2010 (ADAMS No. ML102800524). The NRC staff reviewed the October 6, 2010, submittal, and has determined that additional information is required to complete the review.
The specific information requested is addressed in the enclosure to this letter.
During a discussion with your staff on November 16, 2010, it was agreed that you would provide a response within 30 days from the date of this letter. Please note that if you do not respond to this letter within the prescribed response time or provide an acceptable alternate date in writing, we may reject your application for amendment under the provisions of Title 10 of the Code of Federal regulations (10 CFR), Section 2.108.
IVI. Pacilio
- 2 The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRC's goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-2315.
Sincer r 1/ -1</"\\...-.______
AIsri:!:~~j~ct--;"anager P ant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-237 and 50-249
Enclosure:
Request for Additional Information cc w/encl: Distribution via Listserv
REQUEST FOR ADDITIONAL INFORMATION SHUTDOWN COOLING ISOLATION INSTRUMENTATION EXELON GENERATION COMPANY, LLC DRESDEN NUCLEAR POWER STATION, UNITS 2 AND 3 DOCKET NOS. 50-237 AND 50-249 In reviewing the Exelon Generation Company's (Exelon's) submittal dated October 6, 2010, related to a modification that replaces the temperature-based isolation instrumentation, for the Dresden Nuclear Power Station, Units 2 and 3, the Nuclear Regulatory Commission staff has determined that the following information is needed in order to complete its review:
- 1.
In a letter dated October 6, 2010, Clarification 4 indicates that during a total loss of shutdown cooling (SDC), various alternate core cooling (ACC) methods are available for decay heat removal (DHR) and reactor coolant system (RCS) inventory control. The methods indicated included the condensate/feed and main steam (MS) system, the reactor water cleanup system, control rod drive system and the emergency core cooling systems [including the isolation condenser, high-pressure coolant injection, MS relief valves with the suppression pool cooling mode of the low-pressure coolant injection system].
Discuss use of the above ACC methods for DHR and RCS inventory control during a total loss of SDC under the following plant conditions:
(1)
The reactor pressure vessel (RPV) head is tensioned; (2)
The RPV is detensioned; and (3)
The RV head is removed and the MS line plugs are put in place.
The discussion should address the availability and adequacy of operating procedures to provide clear guidance to the operator for applying the methods.
- 2.
Provide a discussion of plant administration controls, programs or procedures which ensure that the equipment (pumps, valves, and instrumentation) needed for the ACC.
ENCLOSURE
November 23, 2010 M. Pacilio
- 2 The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRC's goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-2315.
Sincerely, IRAJ Eva A. Brown, Senior Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-237 and 50-249
Enclosure:
Request for Additional Information cc w/encl: Distribution via Listserv DISTRIBUTION:
PUBLIC LPL3-2 R/F RidsNrrDorlLpl3-2 Resource RidsNrrPMDresden Resource RidsNrrLATHarris Resource RidsAcrsAcnw_MailCTR Resource RidsOgcRp Resource RidsRgn3MailCenter Resource RidsNrrDorlDpr Resource RidsNrrDeEicb Resource RidsNrrDssSrxb Resource ADAMS Accession No ML103230384 NRR-088 OFFICE LPL3-2/PM LPL3-2/PM LPL3-2/LA LPL3-2/BC LPL3-2/PM NAME EBrown ABillochColon THarris RCarlson EBrown DATE 11/23/10 11/22/10 11/22/10 11/23/10 11/23/10 OFFICIAL RECORD COpy