ML18317A164

Request for Additional Information Regarding Maximum Extended Load Line Limit Plus License Amendment Request (EPID L-2018-LLA-0048) - Non-Proprietary

ML18317A164
Person / Time
Site:	Browns Ferry
Issue date:	11/20/2018
From:	Farideh Saba Plant Licensing Branch II
To:	James Shea Tennessee Valley Authority
Saba F DORL/LPL2-2 301-415-1447
References
EPID L-2018-LLA-0048
Download: ML18317A164 (10)

Text

OFFICIAL USE ONLY PROPRIETARY INFORMATION UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 November 20, 2018 Mr. Joseph W. Shea Vice President, Nuclear Regulatory Affairs and Support Services Tennessee Valley Authority 1101 Market Street, LP 4A Chattanooga, TN 37402-2801

SUBJECT:

BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2, AND 3 - REQUEST FOR ADDITIONAL INFORMATION REGARDING MAXIMUM EXTENDED LOAD LINE LIMIT PLUS LICENSE AMENDMENT REQUEST (EPID L-2018-LLA-0048)

Dear Mr. Shea:

By letter dated February 23, 2018, as supplemented by letters dated March 7, 2018, and .

July 23, 2018, Tennessee Valley Authority (TVA, the licensee) submitted a license amendment request (LAR) to Renewed Facility Operating License Nos. DPR-33, DPR-52, and DPR-68 for Browns Ferry Nuclear Plant (BFN), Units 1, 2, and 3. The proposed LAR would allow operation of BFN units in the expanded Maximum Extended Load Line Limit Analysis Plus (MELLLA+)

operating domain and use of the Detect and Suppress Solution - Confirmation Density stability solution.

The NRC staff reviewed the licensee's submittal and determined that additional information is needed. A draft request for additional information (RAI) from Nuclear Regulatory Commission (NRC) staff in the Office of Nuclear Reactor Regulation (NRR), Division of Engineering, from Mechanical Engineering and lnservice Testing Branch (EMIB) was forwarded by electronic mail (e-mail) to TVA on August 11, 2018. Also draft RAls from the PRA [Probabilistic Risk Assessment] Operations and Human Factors Branch (APHB) staff in Division of Risk Assessment of NRR was emailed to TVA on September 17, 2018. TVA and the NRC staff discussed APHB RAls during a regulatory audit on October 10, 2018, at the Excel Services Corporation in Rockville, MD. Subsequently, the NRC staff e-mailed the revised draft RAls to TVA on October 23, 2018, as discussed during the audit. The NRC staff's official RAls from EMIB and APHB are provided in Enclosures 1, 2, and 3.

The NRC staff has determined that its documented RAI in Enclosure 1 contains proprietary information pursuant to Title 10 of the Code of Federal Regulations 2.390, "Public inspections, exemptions, requests for withholding." Accordingly, the NRC staff has prepared a redacted, nonproprietary version (Enclosure 2).

Enclosure 1 transmitted herewith contains Sensitive Unclassified Non-Safeguard Information. When separated from Enclosure 1, this document is decontrolled.

OFFICIAL USE ONLY PROPRIETARY INFORMATION

OFFICIAL USE ONLY PROPRIETARY INFORMATION J. Shea By an e-mail dated October 25, 2018, Mr. Daniel Green of your staff proposed to submit TVA's responses to the EMIB and APHB RAls by December 14, 2018, with the exception of a response to APHB RAl-3 specific crew times for recognition of an Anticipated Transient Without Scram (ATWS) following a dual recirculation pump trip (2RPT), which was requested_ by NRC during the BFN MELLLA+ audit. TVA proposed to provide the specific crew times for recognition of an ATWS following a 2RPT by January 18, 2019. The NRC staff agreed with TVA's proposed response dates.

If you have any questions, please contact me at 301-415-1447 or Farideh.Saba@nrc.gov.

Sincerely, Farideh E. Saba, Senior Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-259, 50-260, and 50-296,

Enclosures:

1. RAI from EMIB (Proprietary)

2. RAI from EMIB (Non-Proprietary)

3. RAI from APHB cc w/o Enclosure 1: Listserv OFFICIAb U&li ONbY PROPRIETARY INFORMATION

OFFICIAL USE ONLY PROPRIETARY INFORMATION ENCLOSURE 2 NON-PROPRIETARY REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION DIVISION OF ENGINEERING MECHANICAL ENGINEERING AND INSERVICE TESTING BRANCH TO TENNESSEE VALLEY AUTHORITY REGARDING MAXIMUM EXTENDED LOAD LINE LIMIT PLUS LICENSE AMENDMENT REQUEST FOR BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2, AND 3 DOCKET NOS. 50-259, 50-260, AND 50-296 OFFICIAL USE ONLY PROPRIETARY INFORMATION

OFFICIAb US& ONbY PROPRl&TARY INFORMATION REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION DIVISION OF ENGINEERING MECHANICAL ENGINEERING AND INSERVICE TESTING BRANCH TO TENNESSEE VALLEY AUTHORITY REGARDING MAXIMUM EXTENDED LOAD LINE LIMIT PLUS LICENSE AMENDMENT REQUEST FOR BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2, AND 3 DOCKET NOS. 50-259, 50-260, AND 50-296 BACKGROUND By letter dated February 23, 2018 (Agencywide Documents Access and Management System

• (ADAMS) Accession No. ML180798140), as supplemented by letters dated March 7, 2018 (ADAMS Accession No. ML18067A495), and July 23, 2018 (ADAMS Accession No. ML18205A498), Tennessee Valley Authority (TVA, the licensee) submitted a license amendment request (LAR) to Renewed Facility Operating License Nos. DPR-33, DPR-52, and DPR-68 for Browns Ferry Nuclear Plant (BFN), Units 1, 2, and 3, respectively. The proposed LAR would allow operation of BFN units in the expanded Maximum Extended Load Line Limit Analysis Plus (MELLLA+) operating domain and use of the Detect and Suppress Solution -

Confirmation Density stability solution.

The Nuclear Regulatory Commission (NRC) staff from the Office of Nuclear Reactor Regulation, Division of Engineering, from Mechanical Engineering and lnservice Testing Branch (EMIB) reviewed the licensee's submittals and determined that the following request for additional information (RAI) is needed to complete its review.

The NRC staff determined that the following RAI contains proprietary information pursuant to Title 10 of Code of Federal regulations, Section 2.390. Proprietary information is identified by bold text enclosed within double brackets, as shown here ((example proprietary text)).

EMIB RAl-1 Steam Dryer is a safety significant component that is required to maintain its structural integrity so that no loose parts are generated. Any loose parts from steam dryer can affect safety related components in performing their safety function. In Section 3.4.2 of Attachment 5 (page 3-13 of General Electric Hitachi Report NEDC-33877P, Revision 0) to LAR dated February 23, 2018, TVA provided the minimum alternating stress ratio (MASR) at limiting or maximum stress location due to high cycle fatigue for the replacement steam dryers (RSDs ). The MASR is needed to verify the structural integrity of the RSDs for the combined extended power uprate (EPU) and MELLLA+ operating conditions. The ((

)). Based on BFN Enclosure 2 OFFICIAb US& ONbY PROPRl&TARY INFORMATION

OFFICIAL USE ONLY PROPRIETARY INFORMATION

)).1 Based on BFN Unit 3 power ascension data, the ((

)). Provide the updated MASR value and the limiting location for the RSDs for the combined EPU and MELLLA+ operating conditions to ensure that the RSDs will maintain their structural integrity.

I The information within bolded double brackets is redacted in this Enclosure.

OFFICIAL USE ONLY PROPRIETARY INFORMATION

ENCLOSURE 3 REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION DIVISION OF RISK ASSESSMENT PRA OPERATIONS AND HUMAN FACTORS BRANCH TO TENNESSEE VALLEY AUTHORITY REGARDING MAXIMUM EXTENDED LOAD LINE LIMIT PLUS LICENSE AMENDMENT REQUEST FOR BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2, AND 3 DOCKET NOS. 50-259, 50-260, AND 50-296

REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION DIVISION OF RISK ASSESSMENT PRA OPERATIONS AND HUMAN FACTORS BRANCH TO TENNESSEE VALLEY AUTHORITY REGARDING MAXIMUM EXTENDED LOAD LINE LIMIT PLUS LICENSE AMENDMENT REQUEST FOR BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2, AND 3 DOCKET NOS. 50-259, 50-260, AND 50-296 BACKGROUND By letter dated February 23, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML180798140), as supplemented by letters dated March 7, 2018 (ADAMS Accession No. ML18067A495), and July 23, 2018 (ADAMS Accession No. ML18205A498), Tennessee Valley Authority (TVA, the licensee) submitted a license amendment request (LAR) for an amendment to Renewed Facility Operating License Nos.

DPR-33, DPR-52, and DPR-68 for Browns Ferry Nuclear Plant (BFN), Units 1, 2, and 3, respectively. The proposed LAR would allow operation in the expanded Maximum Extended Load Line Limit Analysis Plus (MELLLA+) operating domain, and use of the Detect and Suppress Solution - Confirmation Density stability solution.

The Nuclear Regulatory Commission (NRC) staff from the Office of Nuclear Reactor Regulation, Division of Risk Assessment, from PRA [Probabilistic Risk Assessment] Operations and Human Factors Branch (APHB) reviewed the licensee's submittals and determined that the following request for additional information (RAI) is needed to complete its review.

Regulatory Bases The Title 10 of the Code of Federal Regulations (10 CFR) Requirements that apply to this review include the following:

• 10 CFR 50.36, "Technical specifications," which contains regulatory requirements related to the contents of the technical specifications {TSs). Specifically, 10 CFR 50.36(a)(1) states, "Each applicant for a license authorizing operation of a production or utilization facility shall include in its application proposed TSs in accordance with the requirements of this section. A summary statement of the bases or reasons for such specifications, other than those covering administrative controls, shall also be included in the application, but shall not become part of the technical specifications." Section 50.36(c)(3) states that "[s]urveillance requirements are Enclosure 3

requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the limiting conditions of operation [LCOs] will be met."

• 10 CFR 50.62, "Requirements for reduction of risk from anticipated transients without scram (ATWS) events for light-water-cooled nuclear power plants," which requires licensees to provide the means to address an ATWS event, an Anticipated Operational Occurrence defined in Appendix A of this part, followed by the failure of the reactor trip portion of the protection system specified in General Design Criterion 20 of Appendix A.

The NRC staff reviews the human performance aspects of LARs utilizing the review guidance in NUREG-1764 Rev. 1, "Guidance for the Review of Changes to Human Actions" (ADAMS 1

Accession No. ML072640413). In accordance with the generic risk categories established in Appendix A to NUREG-1764, the tasks under review are involved in the safety injection sequence and actions involving risk-important systems and are, therefore, considered "risk important." Due to this risk importance, the NRC staff will perform a "Level One" review, the most stringent of the graded reviews possible under the guidance of NUREG-1764.

Note: This assessment of risk is only for purposes of scoping the human factors review and may not necessarily align with the licensee's assessment of risk importance or that of other portions of the NRC staff review. This assessment is not intended to be equivalent to the assessment of risk performed with other methods, especially those using plant-specific data and NRG-accepted methods of probabilistic risk analysis and human reliability analysis.

Request for Additional Information APHB RAl-1 Section 10.6 of Attachment 6, NEDC-33877, to the LAR dated, February 23, 2018, states that two new operator actions are required to operate in the MELLLA+ domain. Confirm that these two new operator actions do not impact operator response times or actions associated with any ATWS or dual recirculation pump trip (2RPT) ATWS-lnstability mitigation requirements. Explain how the operator actions associated with ATWS or 2RPT ATWS-lnstability mitigation are implemented and controlled when operating in the MELLLA+ domain.

APHB RAl-2 Section 10.5.3 of Attachment 6, NEDC-33877, to the LAR dated, February 23, 2018, states, in part:

The operator responses to anticipated occurrences, accidents, and special events for CLTP [current licensed thermal power] with MELLLA+ conditions are basically the same as for CLTP conditions.

Conditions during an A TWS are potentially more severe post-reactor RPT during MELLLA+ operation. At reduced flow rates with power at 120% of the OLTP

[original licensed thermal power], the post-RPT power level may be slightly higher during MELLLA+ operation. RPV [reactor pressure vessel] water level would potentially drop quicker and containment heat up would initially be quicker if power level is slightly higher. This would potentially reduce the time for operator response and this was assessed for PRA impact.

The PRA impact review determined that the effect on operator response times is negligible and resulted in no changes to the human error probabilities associated with short-term ATWS response actions.

Describe how the impact of the potential reduction in time for existing operator response time described above was evaluated from a human factors perspective.

APHB RAl-3 The enclosure of the BFN letter dated July 23, 2018 (ADAMS Accession No. ML18205A498),

reports average operator crew action times that appear to be very low relative to the average action times for other licensees implementing MELLLA+ at similar units. Provide the raw results for crew operator action times including a listing of the action times for each crew including training failures that required remediation.

ML18312A427 (Proprietary)

ML18317A164 (Non-Proprietary)

• via email OFFICE DORL/LPLll-2/PM DORL/LPLll-2/LA DE/EMIB/BC*

NAME FSaba BClayton SBailey (ITseng for)

DATE 11/15/18 11/20/18 06/29/18 OFFICE Dra/APHB/BC* DORL/LP LI 1-2/BC DORL/LPLll-2/PM NAME CFong UShoop (RSchaaf for) FSaba DATE 10/22/18 11/19/18 11/20/18