ML20239A968

NRR E-mail Capture - Fermi 2 LAR: RAI for Revision to Technical Specifications to Change the Surveillance Intervals to Accommodate a 24-Month Fuel Cycle

ML20239A968
Person / Time
Site:	Fermi
Issue date:	08/12/2020
From:	Shilpa Arora NRC/NRR/DORL/LPL3
To:	Offerle M DTE Energy Services
References
L-2019-LLA-0249
Download: ML20239A968 (6)

Text

From:

Arora, Surinder Sent:

Wednesday, August 12, 2020 9:31 AM To:

Margaret M Offerle Cc:

Salgado, Nancy

Subject:

Fermi 2 LAR: RAI for Revision to Technical Specifications to change the surveillance intervals to accommodate a 24-Month Fuel Cycle (EPID L-2019-LLA-0249)

Attachments:

EICB RAIs_REVISED.docx

Dear Ms. Offerle,

By letter dated November 8, 2019, ((Agencywide Documents Access Management System (ADAMS)

Accession No. ML19312A110), DTE Energy Company (DTE), the licensee, submitted for the NRC staff review and approval a license amendment to the Fermi Unit 2 (Fermi 2) Technical Specifications. The proposed amendment requests revision to the Fermi 2 Technical Specifications to change the surveillance intervals to accommodate a 24-Month Fuel Cycle.

The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing the above application and has determined that a response to the attached request for additional information (RAI) is needed to complete its review. Please let us know if you need to have a clarification call with the NRC staff to discuss the RAI questions. If no clarification call is needed, please provide your response to the requested information on docket within 30 days of the receipt of this email.

Thanks.

Sincerely, SURINDER ARORA, PE Project Manager, Fermi 2 US NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION (NRR)

DIVISION OF OPERATING REACTOR LICENSING (DORL)

Plant Licensing Branch III (LPL3)

Phone: 301 415-1421 Email: Surinder.Arora@nrc.gov Docket No. 50-341 EPID: L-2019-LLA-0249 OFFICE DORL/lpl3/PM DORl/lpl3/BC NAME SArora NSalgado DATE 8/ 11 /20 8/12/20

Hearing Identifier:

NRR_DRMA Email Number:

757 Mail Envelope Properties (MN2PR09MB46833C910DD6679413F4CF5B94420)

Subject:

Fermi 2 LAR: RAI for Revision to Technical Specifications to change the surveillance intervals to accommodate a 24-Month Fuel Cycle (EPID L-2019-LLA-0249)

Sent Date:

8/12/2020 9:30:43 AM Received Date:

8/12/2020 9:30:43 AM From:

Arora, Surinder Created By:

Surinder.Arora@nrc.gov Recipients:

"Salgado, Nancy" <Nancy.Salgado@nrc.gov>

Tracking Status: None "Margaret M Offerle" <margaret.offerle@dteenergy.com>

Tracking Status: None Post Office:

MN2PR09MB4683.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 1417 8/12/2020 9:30:43 AM EICB RAIs_REVISED.docx 31769 Options Priority:

Normal Return Notification:

No Reply Requested:

No Sensitivity:

Normal Expiration Date:

REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT TO CHANGE SURVEILLANCE INTERVALS TO ACCOMMODATE A 24-MONTH FUEL CYCLE FERMI POWER PLANT, UNIT 2 DTE ENERGY COMPANY DOCKET NO. 50-341 By letter dated November 8, 2019, (Agencywide Documents Access Management System (ADAMS) Accession No. ML19312A110), DTE Energy Company (DTE), the licensee, submitted for staff review and approval a license amendment request (LAR) to the Fermi Unit 2 (Fermi 2)

Technical Specifications (TS). The proposed amendment requests changes to the Fermi 2 TS surveillance requirements (SRs) to accommodate a 24-month fuel cycle.

Applicable Regulation and Guidance Title 10 of the Code of Federal Regulations (10 CFR), Section 50.36(c)(3) states, in part, that SRs relating to test, calibration, or inspection, to assure that the necessary quality of the system and components is maintained, that facility operation will be within safety limits, and that the limiting conditions for operation will be met. Generic Letter (GL) 91.04, Changes in Technical Specification Surveillance Intervals to Accommodate a 24-Month Fuel Cycle states, in part, that the effect on safety due to the increase in SR intervals is small based contingent upon historical plant performance data and that previous assumptions in the plant licensing basis for the affected equipment are not invalidated by the proposed SR interval increase.

Based on the above, the U.S. Nuclear Regulatory Commission (NRC) staff requests the following additional information to confirm that Response Time Testing (RTT) surveillance tests proposed new intervals, will be based on verifiable methodologies. This information is needed to provide a sufficient technical basis for satisfying the requirements of 10 CFR 50.36(c).

EICB-RAI-01A Engineering Report DTE-19001 Surveillance Historical Failure Analysis in Support of a 24 Month Fuel Cycle License Amendment Request (ADAMS Accession No. ML20175A788),, Fermi 2 Technical Specification Event Unique Failures states, in part, with regard to the failure of transmitter B21N095B that the identified failure is unique and does not occur on a repetitive basis and is not associated with a time-based failure mechanism. The report also concludes that this failure will have no impact on an extension to a 24-month surveillance. This is consistent with the description of the failure of the same transmitter described In the Fermi 2 LAR for TS 3.3.2.2, Feedwater and Main Turbine High Water Level Trip Instrumentation". With regard to B21N095Bs failure, the licensee notes ".and no time-based failure mechanism was apparent since there were no similar failures identified."

A review of the applicable Fermi 2 SR history for this function identified only one occurrence where the as-found calibration data for the Division 2 Reactor Level Narrow Range Transmitter (B21N095B) exceeded the specified as-found tolerance for the transmitter. The licensee indicated that this failure would have been discovered solely through the performance of this SR. The same transmitter, i.e., B21N095B, was also cited under TS 3.5.5.1, "Emergency Core Cooling System (ECCS) Instrumentation" with a similar discussion that this transmitter's malfunction was solely detectable through surveillance testing but was a unique failure.

However, for transmitter B21N095B, the failure analysis report, DTE-19001 revision 1, under, event #0766, documents that the work order (WO) 29640637 that analyzed this transmitter's failure concluded, "Transmitter probably an original Installation, went out due to age." A transmitter failing due to age would presumably have a time-based failure mechanism.

This does not appear consistent with statements in the Fermi LAR that suggest there was no time-based failure mechanism for transmitter B21N095B considering the referenced WO states that the transmitter failure was likely due to age. It also does not appear consistent with the evaluation of event #0766 in Attachment 5 of DTE-19001 revision 1.

In this circumstance, age-related failure presents a greater potential for being undetected for a longer period of time with an Increased surveillance Interval of 24 months. In addition, the failure analysis report states that this transmitter was an original Installation, which suggests that this may not be the only transmitter with extended Inservice time since it was installed.

However, the failure analysis report does not reach this level of detail.

Provide more detail about how the proposed surveillance testing Interval increase to 24 months would be sufficient to address age-related failures such as the that described for transmitter B21N095B considering this transmitters failure was deemed age related and presumably could remain in a potentially inoperable condition for a longer period of time without detection with a 24 month interval.

Clarify if there is a program in place to replace transmitters and other electronic equipment at the end of their expected life If so, please provide a description of this program and verify this program is accounted for in the proposed 24-month surveillance program as supported by the technical basis provided in this LAR.

EICB-RAI-01B Engineering Report DTE-19001, revision 1, Section 6.1, defines UNIQUE FAILURES, or Category D as a type of failure that does not occur on a repetitive basis and is not associated with a time-based failure mechanism. Section 8, Conclusions and Recommendations of DTE-19001 goes on to state, in part, that there is no evidence of time-based failure mechanism that would invalidate conclusions regarding impact on safety or system availability. A similar statement regarding system availability is also located in the Category D definition. The goal of a surveillance test is to ensure that a structure, system or component is operable.

Verify that the conclusion statements in DTE-19001, revision 1, refer to sufficient evidence that system operability determinations will not be impacted by the proposed surveillance interval increase.

EICB-RAI-02 In DTE-18001, Revision 0, Instrument Drift Analysis Design Guide in Support of 24-Month Fuel Cycle Extension Project, ADAMS Accession No. ML19312A110 (Enclosure 7) Section 2, Drift Analysis Scope states, in part, that the approaches described in this design guide can be applied to all devices that are surveilled or calibrated where As-Found and As-Left data is recorded and that a given device may be justified not to require drift analysis in accordance with this design guide, if appropriate. Justification for not requiring drift analysis may potentially be appropriate for digital components such as transmitters. It is not clear if the design guide considers potential digital technologies and it does not make any specific distinction for digital components or their unique aspects beyond an acknowledgement for digital indicators. The staff recognizes that digital technologies may have unique failure modes different than the conventional analog components.

Justify that the drift analysis methodology in DTE-18001, Rev. 0, adequately accounts for digital components and their unique aspects that could affect instrument drift (e.g. potential digital failure modes).