ML18197A436
| ML18197A436 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 07/18/2018 |
| From: | Marshall M Plant Licensing Branch 1 |
| To: | Bryan Hanson Exelon Generation Co |
| Marshall M, NRR/DORL/LPLI, 415-2871 | |
| Shared Package | |
| ML18197A436 | List: |
| References | |
| EPID L-2016-LRM-0001 | |
| Download: ML18197A436 (5) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 July 18, 2018 LICENSEE:
Exelon Generation Company, LLC FACILITY:
CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 AND 2
SUBJECT:
SUMMARY
OF MAY 21, 2018, MEETING WITH EXELON GENERATION COMPANY, LLC, ON PLANNED SUBMITTAL OF RISK-INFORMED LICENSE AMENDMENT AND EXEMPTION REQUESTS CONCERNING RESOLUTION OF GENERIC ISSUE 191 (CAC NOS. MF8521 AND MF8522; EPID L-2016-LRM-0001)
On May 21, 2018, a Category 1 public meeting was held between the U.S. Nuclear Regulatory Commission (NRC) and representatives of Exelon Generation Company, LLC (Exelon, the licensee) at NRC Headquarters, One White Flint North, 11555 Rockville Pike, Rockville, Maryland. The purpose of the meeting was for Exelon Generation Company, LLC to provide an overview of its planned license amendment and exemption requests (submittal) 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 NRC in July 2018. The meeting notice and agenda, dated May 4, 2018, are available in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML18137A142. The presentation material used by the licensee is available in ADAMS at Accession No. ML18136A493. A list of attendees is enclosed.
The licensee provided a detailed description of its simplified risk-informed approach. The Exelon representatives emphasized that delta core damage frequency and delta large early release frequency would be calculated outside of the Calvert Cliffs probabilistic risk assessment (PRA). Additionally, the licensee emphasized that it does not plan to use conditional failure probabilities from the Calvert Cliffs PRA. The licensee informed the NRC staff that debris effects downstream of the strainers will be addressed deterministically using NRC-accepted methodologies. In response to NRC staff questions, the license stated that the planned submittal will not need the methodologies described in WCAP-17788, "Comprehensive Analysis and Test Program for GSl-191 Closure" (ADAMS No. ML15210A667). However, the license would need the portion of the NRC staff's safety evaluation that is supposed to address boron precipitation. The Exelon representatives concluded their presentation by describing the format of the planned submittal. The licensee plans to request NRC approval of the methods in the planned submittal - not the results.
The NRC staff informed the licensee that:
The submittal needs to include a discussion of the criteria for screening plant modes and secondary systems breaks.
The risk-informed portion of the submittal needs to include a discussion of the consideration of seismic, fire, and other external hazards.
For the three manual (or human) actions that that will be discussed in the submittal, the NRC will conduct a human factors review of the actions.
The submittal needs to include a description of how erosion of calcium silicate and fiber debris is handled in the analysis.
The submittal needs to include a discussion of the orientation of the breaks used in the
- analysis.
The submittal needs to include a clear description of the deterministic strainer structural margin.
The NRC staff may request a regulatory audit of the Break Analysis Debris Generator, Nuclear Accident Risk Weighted Analysis, and risk calculations.
The submittal needs to include clear definitions of loss-of-coolant accident sizes and a description of the binning method used for loss-of-coolant accident sizes.
The submittal needs to include clear descriptions of the input parameters used in the parametric sensitivity analysis.
The licensee needs to explain, in the submittal, any unexpected or non-intuitive results from the parametric sensitivity analysis.
Additionally, the NRC staff suggested:
The licensee, in the submittal, should discuss the occurrence of (or lack thereof) flashing.
The licensee, in the submittal, should include a detailed discussion explaining plant-specific testing resulting in small and large pieces of debris reducing strainer head loss.
The licensee, in the submittal, should discuss any head loss tests from the 2010 Test for Success Campaign that was not included in the analysis.
The licensee, in the submittal, should include a summary description of each conventional, chemical, and clean head loss test.
The licensee should review NRC staff's request for additional information concerning model uncertainty ~nd parametric sensitivity analysis on ongoing and completed NRC staff reviews of risk-informed closure options for Gl-191.
Members of the public attended the meeting. No Public Meeting Feedback forms were received. During the meeting, the NRC staff received the following comments from the public:
It was unclear during the meeting what is meant by conservative.
The terms used during the meeting were not well defined.
It was confusing during the meeting to determine who was talking.
Some of the numbers discussed during the meeting seem to come out of thin air.
No regulatory decisions were made during the public meeting. Please direct any inquiries to me at (301) 415-2871 or Michael.Marshall@nrc.gov.
Docket Nos. 50-317 and 50-318
Enclosure:
List of Attendees cc: Listserv Michael L. Marshall, Jr., Senior Project Manager Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
LIST OF ATTENDEES MAY 21, 2018, 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 Name Organization Eric Federline MPR Associates, Inc.
Tim Sande ENERCON Ron Holloway Wolf Creek Nuclear Operatinq Corporation Andre Drake Exelon Generation Company, LLC (Exelon)
Enrique Villar Exelon John Tsao U.S. Nuclear Regulatory Commission (NRC)
Christopher Junqe Exelon Steve Smith NRC Kenneth Greene Exelon Keith Tetter NRC Craig Sellers Exelon Matthew Yoder NRC Paul Klein NRC Candace de Messieres NRC Jeff Chizever Exelon Bryce Lehman NRC Steve Bloom NRC John Hardin Exelon Michael Marshall NRC Vic Cusumano NRC Mehdi Reisi Fard NRC Osvaldo Pensado Southwest Research Institute Caroline Tilton NRC Marv Lewis self Enclosure
Package: ML18198A292 Meeting Notice: ML18137A142 Meeting Summary: ML18197A436 Handouts: ML18136A493 OFFICE NRR/DORULPL 1/PM NAME MMarshall DATE 07/17/18 NRR/DORULPL 1/BC NRR/DORULPL 1/PM JDanna*
MMarshall 07/18/18 07/18/18