ML17310B510
| ML17310B510 | |
| Person / Time | |
|---|---|
| Site: | Harris, Grand Gulf, Vogtle  |
| Issue date: | 11/22/2017 |
| From: | Ellen Brown Special Projects and Process Branch |
| To: | Entergy Operations |
| Brown E, 301-415-2315 | |
| References | |
| CAC MG0109, CAC MG0110, CAC MG0111, CAC MG0112, EPID L-2017-LRO-0020 | |
| Download: ML17310B510 (5) | |
Text
LICENSEES:
FACILITIES:
SUBJECT:
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, 0.C. 20555-0001 November 22, 2017 Entergy Operations, Inc.; Duke Energy Progress, LLC; and Southern Nuclear Operating Company, Inc.
Grand Gulf Nuclear Station, Unit 1; Shearon Harris Nuclear Power Plant, Unit 1; and Vogtle Electric Generating Plant, Units 1 and 2
SUMMARY
OF OCTOBER 10, 2017, MEETING WITH ENTERGY OPERATIONS, INC.; DUKE ENERGY PROGRESS, LLC; SOUTHERN NUCLEAR OPERATING COMPANY, INC.; AND NUCLEAR ENERGY INSTITUTE TO DISCUSS PILOT SUBMITIALS USING TORNADO MISSILE EVALUATOR METHODOLOGY (EPID L-2017-LR0-0020)
On October 10, 2017, the U.S. Nuclear Regulatory Commission (NRC) staff conducted a Category 1 public meeting with Entergy Operations, Inc. (Entergy), Duke Energy Progress, LLC (Duke), Southern Nuclear Operating Company, Jnc. (SNC), and the Nuclear Energy Institute (NEI) at NRG Headquarters, 11545 Rockville Pike, Two White Flint North, Rockville, Maryland.
The purpose of the meeting was to discuss the NRC staff's efforts in support of the development of NEl's Tornado Missile Risk Evaluation (TMRE) Tool. Revision 1 of NEI 17-02, Tornado Missile Risk Evaluator (TMRE) Industry Guidance Document," was provided in support of a previous meeting and is available in the Agencywide Documents Access and Management System (ADAMS) under Accession No. ML17268A023. The licensees' presentations are available in ADAMS under Accession Nos. ML17283A412 and ML17283A416. The NRG staff's methodology feedback document was briefly discussed as part of this meeting and is available in ADAMS under Accession No. ML172358148.
BACKGROUND Revision 1 to NEI 17-02 provides a risk-informed option to assess the risk posed by tornado missiles at any site to determine whether additional physical protection is warranted. This methodology is known as the TMRE. Another methodology, known as TORMIS, is used to determine the probability of components being struck and disabled by a tornado-generated missile, and was accepted for use by the NRC. In cases where some components were not in conformance with a plant's licensing basis, licensees can use the TORMIS methodology as a means for demonstrating that the probability of these components being struck by a tornado-generated missile was low enough to justify that protection from tornado-generated missiles was not required. Several licensees have incorporated the TORMIS methodology into their plant-specific licensing basis. One of the advantages of TMRE is that, if approved, it is intended to be applied regardless of the vintage of the plant or the content of the plant's licensing basis.
On August 30, 2017, the NRG staff met with a focus on the pending TMRE submittals for SNC's Vogt)e Electric Generating Plant (Vogtle) and Duke's Shearon Harris Nuclear Power Plant (Harris). Both licensees summarized their applications. The NRC staff had some questions including the basis for treatment of short-term operator actions (i.e., those that need to be executed within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of the initiating event) and indicated a concern with nonconservative assumptions and the feasibility of those actions. Both licensees indicated that work was still ongoing related to the approach to addressing the recovery actions related to a loss of offsite power.
DISCUSSION During the meeting, Entergy presented information related to the pending Grand Gulf Nuclear Station (GGNS) submittal. The licensee covered the current licensing and design bases related to tornado missiles bases, including the proposed justification for why the proposed changes constituted no significant hazards. The NRC staff reminded the lfcensee that significant hazards consideration reviews were not risk-informed, but reflect deterministic considerations including the significance of the effect of the change on accidents and malfunctions previously analyzed, among other requirements.
The licensee provided a listing of the vulnerabilities identified during its walkdowns. The presentation identified the scope of the vulnerabilities identified and presented the contribution of the compliant and degraded cases to the initiating event frequencies. The NRC staff questioned the initiating event frequency contributions from the degraded case for the Fujita Prime (P) 2 and F'3 cases. The NRC indicated that the submittal should address the difference between the compl'1ant case, which represents the plant as if it met the current licensing basis, and the degraded case, which represents the plant as it currently exists (the as-built, as-operated plant).
Appendix E, "TMRE Methodology Sensitivity Studies," of NEI 17-02, Revision 1, examines the sensitivity of missile impact probability values to target size, target elevation, and the distribution of missiles inventory around the plant. The results are used to support the derivation of missile impact probability values. Entergy provided results regarding various model sensitivities. The NRC staff questioned how those sensitivities are reflected in the model, as it was the NRC staff's understanding from previous discussions that the sensitivities would be combined. The licensee indicated that combining the sensitivities would result in too much conservatism and that the sensitivities would be applied separately. The NRC staff indicated that a better discussion regarding sensitivities was needed. It was indicated that NEI and the pilot licensees would look at the assumptions to see how combining the sensitivities would affect the results. It was suggested that this issue be discussed at the next meeting. Additional questions focused on whether Entergy used the TORMIS methodology. The licensee indicated that it reviewed the equipment lists both ways and it was unchanged.
Duke presented a discussion to address feedback received during the August 30, 2017, pre-application meeting regarding the need for additional detail for the defense-in-depth and safety margin discussions. The licensee indicated that as it relates to barriers such as the containment, no nonconforming conditions were identified. Additionally, Duke indicated that in support of demonstrating that its analyses did not have an over-reliance on programmatic activities, no credit was intended to be taken for compensatory measures, nor would the reliability of current actions be credited. For safety margins, Duke indicated that the number of nonconformances was small and that margins would be maintained since non-safety equipment had been identified in the event of a foss of function due to a tornado missile.
The pilot licensees indicated tentative submittal dates in 2017 of October 131h for Vogtle, October 201h for Harris, and October 241h for GGNS. The NRC indicated that the goal was to complete review of the submittals by the end of June 2018.
Members of the public were in attendance. No public Meeting Feedback forms nor comments needing additional follow-up were received.
Docket Nos. 50-400, 50-416, 50-424, and 50-425
Enclosure:
List of Attendees cc: Listserv Sincerely,
/RA/
Eva A. Brown, Senior Project Manager Special Projects and Process Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
LIST OF ATTENDEES U.S. NUCLEAR REGULATORY COMMISSION PUBLIC MEETING CONCERNING PILOT SUBMITTAL$ OF THE TORNADO MISSILE RISK EVALUATOR METHODOLOGY OCTOBER 10 2017 U.S. Nuclear Regulatory Commission Greg Casto Robert Dennig Doug Broaddus G. Ed Miller Nageswara Karipineni Gordon Curran Alex Schwab Mehdi Reisi-Fard Siva Lingam Eva Brown External Stakeholders John Caves, Duke Energy Progress Scott Brinkman, Duke Energy Progress James Hallenbeck, Entergy Operations, Inc.
Richard Harris, Enercon Gary Smith, Enercon Tim Sande, Enercon Ken Lowery, Southern Nuclear Operating Company, Inc.
Stephen Vaughn, Nuclear Energy Institute Abul Hasanat, Entergy Operations, Inc.
James Nadeau, Entergy Operations, Inc.
Douglas Neve, Entergy Operations, Inc.
Mark Humphrey, Engineering Planning, and Management Ryan Sprengel, Exelon Nuclear Christian Williams, Exelon Nuclear John Grobe, Exelon Nuclear Leo Shanley, Jensen Hughes Chris Riedl, Tennessee Valley Authority Dana Millar, Entergy Operations, Inc.
Randall Wilson, Ameren Matthew Mathien, Sargent and Lundy Robert Jacobus, Dominion Energy Justin Hiller, Ameren Tamara Kolb, Ameren John Stang Bobby Smith, Mississippi State Department of Health, Radiological Health Karl Barber, Mississippi State Department of Health, Radiological Health Enclosure
- ML173106510 Public JCaves (john.caves@duke-enerqy.com)
JHallenbeck {jhallen@enterqy.com)
Klowery {kqlowery@southernco.com)
CRiedl (Cjriedl@tva.gov)
LShanley (Lshanley@jensenhughes.com)
RSprengel (Ryan.Sprengel@exeJoncorp.com)
AHasnat {ahasana@entergy.com)
SVaughn (sjv@nei.org)
DMillar (Dmillar@enterqy.com)
SBrinkman (Scott. Brinkman@duke-energy.com)
RHarris (rharris@enercon.com)
KMcElroy(gkmcelro@southernco.com)
GSmith (gsmith@enercon.com)
TSande (tsande@enercon.com)
JNadeau {jnadeau1@entergy.com)
DNeve (dneve@entergy.com)
MHumphrey (msh@epm-inc.com)
CWilliams (Christian.williams@exeloncorp.com)
BSmith (bobby.smith@msdh.ms.gov)
KBarber (karl.barber@msdh.ms.gov)
RWilson (rwilson5@ameren.com)
MMathien (matthew.c.mathien@sargentlundy.com)
RJacobus
( robe rt. t.jacobus@dominionenerqy.com)
JHiller (jhiller@ameren.com TKolb (tkolb@ameren.com)
JStang (jamjz@comcast.net)
JGrobe (john.grobe@exeloncorp.com)
NRC-001 OFFICE NRR/DORULSPB/PM NRR/DORULSPB/LAiT NRR/DORULSPB/LA NRR/DORULSPB/BC NAME EBrown IBetts JBurkhardt DBroaddus (GEMiller for)
DATE 11/13/17 11/09/17 11/13/17 11/22/17