ML15043A199

2/3/2015 Summary of Meeting with Pacific Gas and Electric Regarding Presubmittal Discussion on Alternate Source Term License Amendment Request for Diablo Canyon Power Plant, Units 1 and 2

ML15043A199
Person / Time
Site:	Diablo Canyon
Issue date:	02/19/2015
From:	Siva Lingam Plant Licensing Branch IV
To:
Haskell R
References
TAC MF5596, TAC MF5597
Download: ML15043A199 (4)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 February 19, 2015 LICENSEE: Pacific Gas and Electric Company FACILITY: Diablo Canyon Power Plant, Units 1 and 2

SUMMARY

OF FEBRUARY 3, 2015 PUBLIC MEETING WITH PACIFIC GAS AND ELECTRIC COMPANY REGARDING ALTERNATE SOURCE TERM PRE-SUBMITTAL LICENSE AMENDMENT REQUEST FOR DIABLO CANYON POWER PLANT, UNITS 1 AND 2 (TAC NOS. MF5596 AND MF5597)

On February 3, 2015, a public meeting was held at the U.S. Nuclear Regulatory Commission's (NRC's) main office, located in Rockville, Maryland. This meeting was requested by Pacific Gas and Electric Company (PG&E, the licensee) to propose its approach for use of an Alternate Source Term (AST) in accordance with approved NRC guidance. The licensee's presentation was to support a forthcoming license amendment request (LAR) for Diablo Canyon Power Plant (DCPP), Units 1 and 2. The meeting notice and agenda dated January 21, 2015, are available in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML15021A387. The licensee's presentation slides are available at ADAMS Accession No. ML15029A094. The meeting was attended by NRC staff, PG&E (including representatives),

and members of the public. The Enclosure contains a list of meeting attendees.

Summary The licensee's presentation to propose an AST for DCPP, Units 1 and 2 included a summary of the current licensing basis (CLB), specifically; a radiological analysis, an AST analysis, and Technical Specification changes. The following commentary is a summary of a few discussion points that led to additional exchanges between the NRC staff and the licensee.

The CLB Control Room (CR) Operator dose for DCPP includes an evaluation of the dose from access to/from the site boundary (see DCPP Final Safety Analysis Report (FSAR) page 15.5-37 and Table 15.5-33, Item 5). During the presentation, the licensee proposed to remove this contribution from the AST analysis. The NRC staff recommended that the licensee retain the assessment for CR access dose based on the old source term and include this contribution in the AST evaluation. The staff's recommendation was based on the applicable regulatory requirements; Title 10 of the Code of Federal Regulations (10 CFR) Section 50.67, "Accident source term," and 10 CFR Part 50 Appendix A, Criterion 19, "Control room." Both regulations explicitly state, in part, "access [to] and occupancy of the control room." The NRC staff advised the licensee that since the regulation is clear with respect to access dose, the NRC typically has not emphasized access dose in CR dose consequence analyses in either requests for additional information (RAls) or guidance documents.

During the presentation, the licensee proposed to evaluate the dose consequence for fuel handling accidents (FHAs) without the assumption of a concurrent loss-of-offsite power

(LOOP). The basis for the licensee's assumption is there is no relationship between the dropping of a fuel assembly and grid perturbation, resulting in a LOOP. The NRG staff informed the licensee that there is an assumption of a LOOP, related to a postulated accident {design-basis accident or OBA) leading to a reactor trip, which does not directly correlate to an FHA. As part of the DGPP AST LAR review, the staff will examine pertinent guidance and regulations to ensure this assumption is consistently being interpreted.

The NRG staff informed the licensee that during previous AST LAR reviews for other licensees, utilization of a table or matrix to aggregate GLB OBA assumptions, in contrast to proposed AST assumptions, streamlines the review process. A clearly delineated format typically reduces the number of RAls the NRG may require in order to complete the safety evaluation. As part of the review, NRG staff will need to assess the safety significance of all changes to the GLB parameters used in the affected dose consequence analyses. The NRG staff recommended that for each OBA, the licensee include all the basic parameters used in the dose consequence analyses (i.e., GLB value, revised value, and basis for GLB value changes). The NRG's review would be conducted with greater efficiency if this information were separated into individual tables for each accident evaluated.

Based on the licensee's current projections, the DGPP AST LAR should be finalized and submitted for NRG review within the next few months. No regulatory decisions or commitments were made at the meeting.

Please direct any inquiries to me at 301-415-1564, or by e-mail to Siva.Linqam@nrc.gov.

~~*~

Siva P. Lingam, Project Manager Plant Licensing Branch IV-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-275 and 50-323

Enclosure:

List of Attendees cc w/encl: Distribution via Listserv

LIST OF ATTENDEES U.S. NUCLEAR REGULATORY COMMISSION PUBLIC MEETING WITH PACIFIC GAS AND ELECTRIC COMPANY REGARDING ALTERNATE SOURCE TERM FOR DIABLO CANYON POWER PLANT. UNITS 1 AND 2 FEBRUARY 3, 2015 U.S. Nuclear Regulatory Commission Russell Haskell II Ravinder Grover Siva Lingam Diana Woodyatt Eric Oesterle John Parillo Christopher Vanwert Kenneth Erwin (p) 1 Samir Darbali Kristy Bucholtz (p)

Swagata Som Ryan Alexander (p)

Pacific Gas and Electric Company (including representatives)

Ken Schrader (PG&E) Pedro Salas (AREVA)

Jearl Strickland (PG&E) (p) William Ruland (Steelhead Consulting, LLC)

Eric Nelson (PG&E) (p) Sreela Ferguson (CB&I)

Philippe Soenen (PG&E) (p) Jordan Tyman (CB&I) (p)

Dwight Christensen (PG&E) (p) Alex Cullu (ScienTech)

Jerry Ballard (PG&E) (p) Cornie Holden (Consultant) (p)

Martin Bryen (AREVA) Mike Winsor (Consultant) (p)

Kathy Ashley (AREVA)

Public Member Diane Curran (Mothers for Peace)

Ray Lutz (p)

Nikki Bandel (p) 1 Denotes attendee participant by phone Enclosure

(LOOP). The basis for the licensee's assumption is there is no relationship between the dropping of a fuel assembly and grid perturbation, resulting in a LOOP. The NRC staff informed the licensee that there is an assumption of a LOOP, related to a postulated accident (design-basis accident or OBA) leading to a reactor trip, which does not directly correlate to an FHA. As part of the DCPP AST LAR review, the staff will examine pertinent guidance and regulations to ensure this assumption is consistently being interpreted.

The NRC staff informed the licensee that during previous AST LAR reviews for other licensees, utilization of a table or matrix to aggregate CLB OBA assumptions, in contrast to proposed AST assumptions, streamlines the review process. A clearly delineated format typically reduces the number of RAls the NRC may require in order to complete the safety evaluation. As part of the review, NRC staff will need to assess the safety significance of all changes to the CLB parameters used in the affected dose consequence analyses. The NRC staff recommended that for each OBA, the licensee include all the basic parameters used in the dose consequence analyses (i.e., CLB value, revised value, and basis for CLB value changes). The NRC's review would be conducted with greater efficiency if this information were separated into individual tables for each accident evaluated.

Based on the licensee's current projections, the DCPP AST LAR should be finalized and submitted for NRC review within the next few months. No regulatory decisions or commitments were made at the meeting.

Please direct any inquiries to me at 301-415-1564, or by e-mail to Siva.Lingam@nrc.gov.

/RAJ Siva P. Lingam, Project Manager Plant Licensing Branch IV-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-275 and 50-323

Enclosure:

List of Attendees cc w/encl: Distribution via Listserv DISTRIBUTION:

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