ML17249A320
| ML17249A320 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 09/18/2017 |
| From: | Marshall M Plant Licensing Branch 1 |
| To: | Bryan Hanson Exelon Generation Co |
| Marshall M, NRR/DORL/LPLI, 415-2871 | |
| References | |
| CAC F8521, CAC F8522 | |
| Download: ML17249A320 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 September 18, 2017 LICENSEE: Exelon Generation Company, LLC FACILITY: CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 AND 2
SUBJECT:
SUMMARY
OF AUGUST 16, 2017, MEETING WITH EXELON GENERATION COMPANY, LLC, ON PLANNED SUBMITTAL OF RISK-INFORME!D LICENSE AMENDMENT AND EXEMPTION REQUESTS CONCERNING RESOLUTION OF GENERIC ISSUE 191 (CAC NOS. MF8521 AND MF8522)
On August 16, 2017, a Category 1 public meeting was held between the U.S. Nuclear Regulatory Commission (NRG) and representatives of Exelon Generation Company, LLC (Exelon, the licensee) at NRG Headquarters, One White Flint North, 11555 Rockville Pike, Rockville, Maryland. The purpose of the meeting was for Exelon Generation Col'T)pany, LLC to provide an overview of its planned license amendment and exemption requests concerning the risk-informed resolution of Generic Issue (GI) 191, "Assessment of Debris Accumulation on PWR [Pressurized Water Reactor] Sump Performance," for Calvert Cliffs Nuclear Power Plant, Units 1 and 2 (Calvert Cliffs). The licensee plans to submit the requests to the NRG in February or March 2018. The meeting notice and agenda, dated August 1, 2017, are available in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML17213A824. A list of attendees is enclosed.
The licensee presented information (ADAMS Accession No. ML17249A325) on the technical bases for its planned license amendment and exemption requests concerning the risk-informed resolution of GI 191 for Calvert Cliffs. During its presentation, Exelon emphasized that the approach it plans to use in the submittal relies on methods described in WCAP-16793, Revision 2, "Evaluation of Long-Term Cooling Considering Particulate, Fibrous and Chemical Debris in Recirculating Fluid" (ADAMS Accession No. ML13239A114 ), and not WCAP-17788, Revision 0, "Comprehensive Analysis and Test Program for GI 191 Closure (PA-SEE-1090)" (ADAMS Package Accession No. ML 1521 OA667), which is a topical report currently being reviewed by the NRG. Specifically, the licensee plans to use a deterministic approach regardirig post loss-of-coolant accident debris effects in the reactor vessel. Also, Exelon emphasized that a simplified risk-informed approach would be used in determining conditional failure probabilities and changes in core damage frequencies. The simplified risk-informed approach was described during the meeting. The licensee stated that longitudinal (or "shop") welds would be considered in the population of postulated break locations. The licensee also discussed probabilistic risk assessment acceptability topics such as its planned use of the probabilistic risk assessment from the Calvert Cliffs National Fire Protection Association 805 license amendment request with a gap analysis.
In response to NRG staff questions, the licensee stated that each item in the revised Content Guide for Generic Letter 2004-02 Supplemental Responses (ADAMS Accession
No. ML073110278) for "head loss and vortexing" would be addressed. Also, in response to NRC staff questions, Exelon stated that the following would be included in its submittal:
- a sensitivity assessment of bin sizes used in determining conditional failure probabilities;
- an explanation of test data validity and discrepancies, using graphs and tables as needed; and
- a description of weld conditions for each of the welds considered as a possible break location.
Additionally, the NRC staff suggested that the licensee include in its submittal an explanation justifying the selection and use of a single plant configuration in evaluating the effects of debris recirculation and descriptions of other possible, credible plant configurations.
Members of the public were in attendance. NRC staff did not receive any questions or comments from the members of the public in attendance. No Public Meeting Feedback forms were received.
Please direct any inquiries to me at (301) 415-2871 or Michael.Marshall@nrc.gov.
!//khlf~
Michael L. Marshall, Jr., Senior Project Manager Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-317 and 50-318
Enclosure:
List of Attendees cc w/encl: Distribution via Listserv
LIST OF ATTENDEES AUGUST 16, 2017, MEETING WITH EXELON GENERATION COMPANY. LLC, ON PLANNED SUBMITTAL OF RISK-INFORMED LICENSE AMENDMENT AND EXEMPTION REQUESTS FOR CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 AND 2, CONCERNING RESOLUTION OF GENERIC ISSUE 191
....* R*2 .** <rii: *'* ;:.*.. *.* *** *h ..*ora~izatl~.
Eric Federline MPR Associates, Inc.
Tim Sande ENERCON Ron Holloway Wolf Creek Nuclear Ooeratina Corooration Andre Drake Exelon Generation Comoanv, LLC (Exelon)
Enrique Villar Exelon John Tsao U.S. Nuclear Requlatorv Commission (NRC)
John Hanson Exelon Steve Smith NRC Vic Cusumano NRC CJ Fonq NRC Craia Sellers Exelon Matthew Yoder NRC Paul Klein NRC Candace de Messieres NRC Jeff Chizever Exelon Bryce Lehman NRC Kio Walker ENERCON John Hardin Exelon Michael Marshall NRC Enclosure
ML17249A320 OFFICE NRR/DORL/LPL 1/PM NRR/DORL/LPL 1/LA NRR/DORL/LPL 1/BC NRR/DORL/LPL 1/PM NAME MMarshall LRonewicz Joanna MMarshall DATE 09/18/2017 09/08/2017 09/18/2017 09/18/2017