ML20092F696
| ML20092F696 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 04/03/2020 |
| From: | Siva Lingam Plant Licensing Branch IV |
| To: | |
| Lingam S, 301-415-1564 | |
| References | |
| EPID L-2020-LLA-0060 | |
| Download: ML20092F696 (7) | |
Text
PUBLIC NOTICE NRC STAFF PROPOSES TO AMEND OPERATING LICENSE AT THE GRAND GULF NUCLEAR STATION, UNIT 1 The U.S. Nuclear Regulatory Commission (NRC) staff has received an application dated March 31, 2020 (available in the Agencywide Documents Access and Management System (ADAMS) at Accession No. ML20091M363), from Entergy Operations, Inc. (Entergy, the licensee), for an exigent amendment to the renewed facility operating license for the Grand Gulf Nuclear Station, Unit 1 (Grand Gulf), located in Claiborne County, Mississippi. The licensee requests NRC approval by April 15, 2020.
The proposed exigent amendment would allow for a one-cycle extension of the interval to perform the Grand Gulf Type A integrated leak rate test (ILRT) and drywell bypass leak rate test (DWBT) from the current technical specification (TS) requirement of 11.5 years to 13.5 years.
The licensee requested that the proposed amendment be processed on an exigent basis, in accordance with the provisions in Title 10 of the Code of Federal Regulations (10 CFR)
Section 50.91(a)(6). Under 10 CFR 50.91(a)(6)(i), where the Commission finds that exigent circumstances exist, in that a licensee and the Commission must act quickly and that time does not permit the Commission to publish a Federal Register notice allowing 30 days for prior public comment, and it also determines that the amendment involves no significant hazards considerations, the Commission will either (A) issue a Federal Register notice providing notice of an opportunity for hearing and allowing at least two weeks from the date of the notice for prior public comment; or (B) use local media to provide reasonable notice to the public in the area surrounding a licensees facility of the licensees amendment and of its proposed determination that no significant hazards consideration is involved, consulting with the licensee on the proposed media release and on the geographical area of its coverage. Due to the timing of the
amendment request, the NRC staff is providing this notice in local media pursuant to 10 CFR 50.91(a)(6)(i)(B), and has consulted with the licensee and the NRC regional office on the proposed media release.
The licensee provided the following information to support its need for this exigent license amendment request. The licensee is requesting this extension due to unforeseen circumstances because of the ongoing COVID-19 pandemic, which has resulted in a need to delay the Type A ILRT and DWBT from the current spring 2020 refueling outage to the next spring 2022 refueling outage. The proposed change would permit the Type A ILRT and DWBT to be performed as specified in TS 5.5.12 10 CFR 50, Appendix J, Testing Program, and Surveillance Requirement 3.6.5.1.1 in TS 3.6.5.1, Drywell, respectively, prior to startup following Refueling Outage 23 (spring 2022 refueling outage), which is scheduled to commence in February 2022. As such, the one-cycle extension of the Type A ILRT and DWBT interval would represent a duration of approximately 13.5 years since the last performance of the Type A ILRT and DWBT on October 19, 2008. Additionally, Entergy indicated in its application that the proposed change to extend the Type A ILRT and DWBT would enable Entergy to minimize the number of onsite personnel, thus minimizing the potential exposure of both essential (i.e.,
licensed operators, security personnel, and the emergency response organization) and nonessential personnel to the COVID-19 virus.
As required by 10 CFR 50.91(a), the licensee has provided its analysis of the issue of no significant hazards consideration using the standards in 10 CFR 50.92. Under the NRCs regulations in 10 CFR 50.92, this means that operation of the facility in accordance with the proposed amendment would not (1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety. The licensee and the NRC staff have evaluated this proposed
change regarding the determination of whether or not a significant hazards consideration is involved as described below.
Operation of Grand Gulf, in accordance with the proposed amendment will not involve a significant increase in the probability or consequences of an accident previously evaluated.
The proposed amendment to the TSs involves a one-cycle extension of the Grand Gulf Type A ILRT and the DWBT intervals to 13.5 years. The proposed extensions do not involve either a physical change to the plant or a change in the manner in which the plant is operated or controlled. The Containment is designed to provide an essentially leak-tight barrier against the uncontrolled release of radioactivity to the environment for postulated accidents. As such, the Containment and the testing requirements invoked to periodically demonstrate the integrity of the Containment exist to ensure the plants ability to mitigate the consequences of an accident, and do not involve the prevention or identification of any precursors of an accident. The change in Type A test frequency 13.5 years, measured as an increase to the total integrated plant risk for those accident sequences influenced by Type A testing, based on the internal events probabilistic risk analysis is less than 0.006 person rem/year for Grand Gulf. Electric Power Research Institute (EPRI) Report No. 1009325, Revision 2-A (ADAMS Accession No. ML072970208) states that a very small population is defined as an increase of 1.0 person rem per year or 1 percent of the total population dose, whichever is less restrictive for the risk impact assessment of the extended Type A ILRT intervals. This is consistent with the NRC Final Safety Evaluation for Nuclear Energy Institute (NEI) 94-01 and EPRI Report No. 1009325 (ADAMS Accession No. ML100620847). Moreover, the risk impact when compared to other severe accident risks is negligible. Therefore, this proposed extension does not involve a significant increase in the probability of an accident previously evaluated. In addition, as documented in NUREG-1493, Performance-Based Containment Leak-Test Program, dated September 1995, Types B and C tests have identified a very large percentage of containment
leakage paths, and the percentage of containment leakage paths that are detected only by Type A testing is very small. The Grand Gulf Type A test history supports this conclusion. The integrity of the Containment is subject to two types of failure mechanisms that can be categorized as: (1) activity-based, and (2) time-based. Activity-based failure mechanisms are defined as degradation due to system and/or component modifications or maintenance. The local leakage rate test requirements and administrative controls such as configuration management and procedural requirements for system restoration ensure that Containment integrity is not degraded by plant modifications or maintenance activities. The design and construction requirements of the Containment, combined with the Containment inspections performed in accordance with the American Society of Mechanical Engineers (ASME)
Section XI, and TS requirements serve to provide a high degree of assurance that the Containment would not degrade in a manner that is detectable only by a Type A test. Based on the above, the proposed Type A test interval extension does not significantly increase the consequences of an accident previously evaluated. Therefore, the proposed change does not result in a significant increase in the probability or consequences of an accident previously evaluated.
The proposed amendment will not create the possibility of a new or different kind of accident from any previously evaluated. The proposed amendment to the Grand Gulf TSs involves a one-cycle extension of the Type A ILRT and the DWBT intervals to 13.5 years. The Containment and the testing requirements to periodically demonstrate the integrity of the Containment exist to ensure the plants ability to mitigate the consequences of an accident do not involve any accident precursors or initiators. The proposed change does not involve a physical change to the plant (i.e., no new or different type of equipment will be installed) or a change to the manner in which the plant
is operated or controlled. Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.
The proposed amendment will not involve a significant reduction in a margin of safety. The proposed amendment to the Grand Gulf TS involves a one-cycle extension of the Type A ILRT and the DWBT intervals to 13.5 years. This amendment does not alter the manner in which safety limits, limiting safety system set points, or limiting conditions for operation are determined. The specific requirements and conditions of the TS 10 CFR 50, Appendix J Testing Program for Containment leakage rate testing exist to ensure that the degree of Containment structural integrity and leak-tightness that is considered in the plant safety analysis are maintained. The overall containment leak rate limit specified by TS is maintained. The design, operation, testing methods, and acceptance criteria for Types A, B, and C Containment leakage tests specified in applicable Codes and Standards would continue to be met with the acceptance of this proposed change, since these are not affected by the proposed changes to the Type A test interval. Therefore, the proposed change does not involve a significant reduction in a margin of safety.
Following an initial review of this application, the requested amendment has been evaluated against the standards in 10 CFR 50.92 and the NRC staff has made a proposed determination that the requested amendment involves no significant hazards considerations.
The changes do not significantly increase the probability or consequences of any accident previously considered, nor create the possibility of an accident of a different kind, nor significantly decrease any margin of safety.
The NRC is seeking public comments on this proposed determination that the license amendment request involves no significant hazards considerations. The NRC will consider comments received through April 14, 2020. If the proposed determination that the requested
license amendment involves no significant hazards consideration becomes final, the NRC staff will issue the amendment without first offering an opportunity for a public hearing. An opportunity for a hearing will be published in the Federal Register at a later date and any hearing request will not delay the effective date of the amendment.
The Commission may issue the amendment prior to the expiration of the comment period, should circumstances change such that failure to act in a timely way would result, for example, in derating or shutdown of the facility. Should the Commission take action prior to the expiration of the comment period, it will publish in the Federal Register a notice of issuance.
Before any issuance of the proposed license amendment, the NRC staff will need to make the findings required by the Atomic Energy Act of 1954, as amended, and NRC regulations.
If the NRC staff decides in its final determination that the amendment does involve a significant hazards consideration, a notice of opportunity for a prior hearing will be published in the Federal Register and, if a hearing is granted, it will be held before the amendment is issued.
Comments on the proposed determination of no significant hazards consideration may be (1) telephoned to Jennifer Dixon-Herrity, Chief, Plant Licensing Branch 4, by collect call to 301-415-2967, (2) e-mailed to Jennifer.Dixon-Herrity@nrc.gov, or (3) submitted in writing to Office of Administration, Mail Stop: TWFN-7-A60M, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, ATTN: Program Management, Announcements and Editing Staff.
All comments received by close of business, 4:14 p.m., on April 14, 2020, will be considered in reaching a final determination.
The NRC cautions you not to include identifying or contact information in comment submissions that you do not want to be publicly disclosed in your comment submission. The NRC will post all comment submissions at http://www.regulations.gov, as well as enter the comment submissions into ADAMS. The NRC does not routinely edit comment submissions to remove identifying or contact information.
If you are requesting or aggregating comments from other persons for submission to the NRC, then you should inform those persons not to include identifying or contact information that they do not want to be publicly disclosed in their comment submission. Your request should state that the NRC does not routinely edit comment submissions to remove such information before making the comment submissions available to the public or entering the comment into ADAMS.
A copy of the application may be examined electronically through the NRCs ADAMS in the NRC Library at http://www.nrc.gov/reading-rm/adams.html. Persons who do not have access to ADAMS or who encounter problems in accessing the documents located in ADAMS should contact the NRC PDR Reference staff by telephone at 1 800 397 4209, or 301 415 4737, or by e-mail to pdr.resource@nrc.gov.