ML16245A866
| ML16245A866 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 10/04/2016 |
| From: | Richard Ennis Plant Licensing Branch 1 |
| To: | |
| Ennis R, NRR/DORL/LPLI-II, 415-1420 | |
| References | |
| CAC MF8267, CAC MF8268 | |
| Download: ML16245A866 (5) | |
Text
LICENSEE:
FACILITY:
SUBJECT:
UNITED ST ATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 October 4, 2016 Exelon Generation Company, LLC Limerick Generating Station, Units 1 and 2
SUMMARY
OF AUGUST 30, 2016, MEETING WITH EXELON GENERATION COMPANY, LLC REGARDING PLANNED LICENSE AMENDMENT REQUEST TO IMPLEMENT RISK-INFORMED TECHNICAL SPECIFICATION COMPLETION TIMES FOR LIMERICK GENERATING STATION, UNITS 1 AND 2 (CAC NOS. MF8267 AND MF8268)
On August 30, 2016, 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 to discuss the licensee's plan to submit a license amendment request (LAR) for the Limerick Generating Station (LGS), Units 1 and 2.
The planned submittal would adopt Technical Specifications Task Force (TSTF) Change Traveler TSTF-505, "Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b."
The meeting notice and agenda, dated August 18, 2016, are available in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML16242A002. A list of attendees is enclosed.
The licensee presented an overview of its plans to submit the TSTF-505 LAR for LGS, Units 1 and 2. The presentation closely followed Exelon's slides provided for the meeting (ADAMS Accession No. ML16237A241).
The schedule currently calls for the LAR to be submitted by the end of 2016. Exelon indicated that the LAR would impact about 24 technical specification (TS) limiting conditions for operation and about 75 required actions. Exelon discussed the variances from the TSTF-505 model as shown on slides 4 through 16. Some of the differences from TSTF-505 are due to the LGS TSs being based on the original boiling-water reactor (BWR) Standard Technical Specifications (STS) versus the improved STS (i.e., LGS TSs are based on NUREG-0123, not on NUREG-1433). The licensee indicated that LGS would be the first BWR TSTF-505 submittal to the NRC.
As shown on Exelon slides 8 and 12, two of the proposed variances from TSTF-505 are for TS 3.3.4.2, "End-of-Cycle Recirculation Pump Trip System Instrumentation," and TS 3.6.1.3, "Primary Containment Air Lock." These functions are not currently modeled in the LGS probabilistic risk assessment (PRA) models. The licensee stated its plans to update the PRA models after the LAR is submitted to include these functions. The NRC staff indicated that submitting the LAR before completing the underlying PRA models could result in non-acceptance of the LAR for technical review in accordance with Office of Nuclear Reactor Regulation Office Instruction LIC-109, "Acceptance Review Procedures." The NRC staff suggested that the licensee either update the PRA models before submitting the LAR or not include these variances in the submittal.
The NRC staff made a number of comments regarding TSTF-505 issues related to instrumentation and control (l&C) systems. The NRC staff stated that the l&C technical review will focus, in part, on how it will be determined if a total loss of TS specified safety function has occurred, since a risk-informed completion time (RICT) is not allowed in this condition. The NRC staff stated that l&C systems are different from other systems in some fundamental ways.
For example:
(1)
Most l&C functions involve coincidence voting, while most other systems do not. This means that for most l&C systems, two or more redundancies must be PRA functional (or there is a loss of function).
(2)
There are unique regulatory requirements for the separation of protection and control functions. This interaction increases the number of channels that must be PRA functional.
(3)
Sensors are used to determine plant parameter values. Some plant parameters are spatially distributed. Regulations require the minimum number and location of sensors (for spatially distributed parameters) be identified in the design-basis documentation.
This minimum number and location must be considered when determining if a total loss of function has occurred.
The NRC staff discussed generic TSTF-505 concerns about applying an RICT to components with multiple safety functions. For example, some valves may have a function to open for certain events and close for other events. If the licensee fixes this component in one state (e.g.,
causes a valve to remain in a closed position), then it could be interpreted that this should be considered a total loss of function. The NRC staff indicated that guidance would be issued in the future regarding the loss of function issue. For the time being, the staff encouraged the licensee to review the NRC's slides from the June 20, 2016, meeting with industry for what the staff envisions as a possible success path on this issue.
The NRC staff also indicated that the large number of proposed variances for the LGS TSTF-505 LAR would result in significantly more time for the NRC review. The staff suggested that the licensee take a close look at the variances and decide which ones it really wants to request.
The licensee indicated that it will use the same procedures for implementation of TSTF-505 throughout the Exelon fleet. The NRC staff will have an opportunity to look at the procedures at an upcoming TSTF-505 audit at the Calvert Cliffs Nuclear Power Plant.
Members of the public were in attendance. No public comments were made during the meeting and no public meeting feedback forms were received.
Please direct any inquiries to me at 301-415-1420 or by e-mail at Rick.Ennis@nrc.gov.
Docket Nos. 50-352 and 50-353
Enclosure:
List of Attendees cc w/enclosure: Distribution via Listserv Richard B. Ennis, Senior Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
LIST OF ATTENDEES AUGUST 30, 2016, MEETING WITH EXELON GENERATION COMPANY, LLC LIMERICK GENERATING STATION, UNITS 1 AND 2 PLANNED TSTF-505 LICENSE AMENDMENT REQUEST Name Organization Rick Ennis NRG Eric Benner NRG Maraaret Chernoff NRG Eric Oesterle NRG Robert Beaton NRG Norbert Carte NRG Stephen Dinsmore NRG Joseph Giitter NRG Dan O'Neal NRG Russ Felts NRG Jonathan Evans NRG Kim Green NRG Stacey Rosenberg NRG Ed Miller NRG Alex Klein NRG Khadijah West NRG Doua Broaddus NRG Roy Mathew NRG Gordon Curran*
NRG Georae Budock Exelon Glenn Stewart Exelon Benjamin Sauers Exelon Gene Kelly Exelon Arthur Holtz*
Exelon Victoria Warren Jensen Huahes Barrv Sloane Jensen Hughes Victoria Anderson Nuclear Energy Institute Rob Sura*
Enaineerina Planning and Management, Inc.
Bruce Morgan*
Engineering Planning and Management, Inc.
- by telephone
ML16245A866 Meetina Notice: ML16242A002 Meeting Slides: ML16237A241 OFFICE DORL/LPL 1-2/PM DORL/LPL 1-2/LA DE/EICB/BC NAME REnnis LRonewicz MWaters DATE 09/13/2016 09/12/2016 09/20/2016 OFFICE DORL/LPL 1-2/BC DORL/LPL 1-2/PM NAME DBroaddus REnnis DATE 10/4/2016 10/4/2016