NRC-23-0039, Request for Enforcement Discretion for Technical Specification 3.7.2, Emergency Equipment Cooling Water (Eecw)/Emergency Equipment Service Water (Eesw) System and Ultimate Heat Sink (UHS)

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Request for Enforcement Discretion for Technical Specification 3.7.2, Emergency Equipment Cooling Water (Eecw)/Emergency Equipment Service Water (Eesw) System and Ultimate Heat Sink (UHS)
ML23157A026
Person / Time
Site: Fermi DTE Energy icon.png
Issue date: 06/06/2023
From: Peter Dietrich
DTE Electric Company
To:
Office of Nuclear Reactor Regulation, Document Control Desk
References
NRC-23-0039
Download: ML23157A026 (1)
v • d • e


Text

Peter Dietrich Senior Vice President and Chief Nuclear Officer DTE Electric Company 6400 N. Dixie Highway, Newport, MI 48166 Tel: 734.586.6515 Email: peter.dietrich@dteenergy.com DTE June 6, 2023 NRC-23-0039 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 Fermi 2 Power Plant NRC Docket No. 50-341 NRC License No. NPF-43

Subject:

Fermi Unit 2 Request for Enforcement Discretion for Technical Specification 3.7.2, Emergency Equipment Cooling Water (EECW)/Emergency Equipment Service Water (EESW) System and Ultimate Heat Sink (UHS)

DTE Electric Company (DTE) hereby requests enforcement discretion for Fermi Unit 2 (Fermi 2) from compliance with Technical Specification (TS) 3.7.2, Emergency Equipment Cooling Water (EECW)/Emergency Equipment Service Water (EESW) System and Ultimate Heat Sink (UHS).

For EECW, EESW and UHS systems during current plant operating conditions, TS 3.7.2 requires two EECW/EESW subsystems and the UHS to be operable. If one EECW/EESW system is inoperable (TS 3.7.2 CONDITION B), TS 3.7.2 ACTION B.1 requires the EECW/EESW subsystem to be restored to OPERABLE status within seventy-two (72) hours. If ACTION B.1 cannot be completed, TS 3.7.2 ACTION C.1 requires the plant to be in MODE 3 (hot shutdown) within the subsequent 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

On May 31, 2023, at 2038 Eastern Daylight Savings Time (EDT), while performing 24.208.02 Section 5.1, EESW Pump and Valve Operability Test - Division 1, steps 5.1.20.5.b (Measured Differential Pressure (D/P) less than Maintenance Limit) and 5.1.20.6.b (Measured D/P less than Operability limit) were not met. Upon restoration, it was discovered that TS 3.7.2 CONDITION B would not be met. Further investigation determined that the cause was ferrous material buildup and heat exchanger cleaning activities are required to correct the conditions and restore the equipment to an operable status.

DTE hereby requests that the NRC exercise enforcement discretion as set out in the NRC Enforcement Manual, Appendix F, Notices of Enforcement Discretion. The enforcement discretion requested by DTE will authorize temporary non-compliance with Technical Specification 3.7.2. It is requested that this enforcement discretion be effective from 0400 EDT on June 3, 2023, to 1600 EDT on June 4, 2023.

USNRC NRC-23-0039 Page 2 This request for enforcement discretion has been reviewed and approved by the station's Onsite Safety Review Organization.

The incremental conditional core damage probability (ICCDP) and incremental conditional large early release probability (ICLERP) have been quantified for the requested additional time. The results of the quantification are within the guidance threshold in Nuclear Regulatory Commission (NRC) Enforcement Manual Appendix F, "Notices of Enforcement Discretion."

The enforcement discretion request is provided in the enclosure, which provides the information requested in NRC Enforcement Manual Appendix F, "Notices of Enforcement Discretion."

This request was verbally transmitted to members of the NRC staff on June 2, 2023, at 1800 EDT, with subsequent approval being verbally granted by the NRC on June 2, 2023, at 1927 EDT.

Following the Information provided to the NRC on the conference call on June 2, 2023, at 1800, TS 3.7.2 CONDITION B was met at 0119 on June 3, 2023; 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and 41 minutes prior to the original 72-hour action statement expiration.

No new commitments are being made in this submittal.

Should you have any questions or require additional information, please contact Mr. Eric Frank, Manager-Nuclear Licensing, at (734) 586-4772.

Senior Vice President and C iefNuclear Officer

Enclosure:

Request for Enforcement Discretion for Technical Specification 3.7.2 cc: NRC Project Manager NRC Resident Office Regional Administrator, Region III

Enclosure to NRC-23-0039 Fermi 2 NRC Docket No. 50-341 Operating License No. NPF-43 Request for Enforcement Discretion for Technical Specification 3.7.2

Request for Enforcement Discretion for Technical Specification 3.7.2 Condition B Summary of Issue On May 31, 2023, at 2038 Eastern Daylight Savings Time (EDT), While Performing 24.208.02 Section 5.1, EESW Pump and Valve Operability Test - Division 1, steps 5.1.20.5.b (Measured Differential Pressure (D/P) less than Maintenance Limit) and 5.1.20.6.b (Measured D/P less than Operability limit) were not met. The numbers are listed below:

Measured D/P - 10.55 psid Maintenance Limit - 9.7834 psid Operability Limit - 10.1752 psid Typically, the plant would swap to the alternate heat exchanger based on this condition, but the alternate Heat Exchanger (P4400B001C) was not available and requires restoration due to exceeding its maintenance limit on D/P in December 2022. As a troubleshooting measure, P4400B001C was placed in service and tested. Its D/P was 10.73 which failed to meet the operability limit of 10.1752.

Technical Specification (TS) Limiting Condition for Operation (LCO) 3.7.2, Emergency Equipment Cooling Water (EECW)/Emergency Equipment Service Water (EESW) system and Ultimate Heat Sink (UHS) was entered to support maintenance and Division 1 EECW/EESW were declared inoperable.

In addition, the following TS are also being tracked under Operations Safety Function Determination sheets that would also expire prior to completion of repair activities:

  • 3.8.4 DC Sources - Operating
  • 3.8.7 Distribution Systems - Operating To respond to these issues, formation of an Emergent Issues Team (EIT) and staffing of the Outage Control Center (OCC) was initiated by approximately 2300 EDT on May 31, 2023.

Attempts to flush the drain valves were made but did not improve the measured D/P. Division 1 EESW Heat Exchanger P4400B001A was in service for surveillance testing per 24.208.02.

The questions posed in Nuclear Regulatory Commission (NRC) Enforcement Manual Appendix F, Notices of Enforcement Discretion, Checklist A, are in bold. The information provided by DTE Electric Company (DTE) for Fermi Unit 2 (Fermi 2) follows each question.

1. Did the licensee explain why a formal licensing process is not appropriate to address the issue and why the need for a NOED could not reasonably been avoided? If applicable, this explanation shall address previous instances of the issue and decisions to pursue licensing solutions in the past.

to NRC-23-0039 Page 2 Due to the extensive troubleshooting that was required and starting the LCO at the beginning of the surveillance, a significant portion of the TS-allowed 72-hour Completion Time had already elapsed before a cause was identified. The maintenance activities necessary to repair the Division 1 Heat Exchanger are estimated to take up to an additional 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> beyond the end of the 72-hour Completion Time. For this reason, DTE requests enforcement discretion to allow exceeding the 72-hour Completion Time of Required Action B.1 by an additional 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> to allow for repair of the Division 1 Heat Exchanger and perform necessary post-maintenance testing. Fermi 2 is currently operating in Mode 1 at 100% power. Without this enforcement discretion, Fermi 2 would be required to be in Mode 3 by 1600 EDT on June 3, 2023.

DTE reviewed alternatives to enforcement discretion to ensure that the request could not reasonably be avoided. However, at the time of the cause identification, the remaining duration of the 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> was insufficient to prepare, submit, and receive NRC approval of a license amendment request under 10 CFR 50.90, Application for amendment of license, construction permit, or early site permit, even when considering the provisions for emergency situations discussed in 10 CFR 50.91(a)(5). Fermi 2 also does not have a Risk-Informed Completion Time (RICT) program to allow Completion Time extensions under DTE control (i.e., without prior NRC approval) using risk assessments. The current set of plant conditions are unplanned and have not previously occurred at Fermi 2. As a result, the cause and repair were not immediately apparent and required additional troubleshooting to understand the condition. Enforcement discretion would allow continued plant operation for only that additional time needed to repair the equipment and restore it to operable status and is less than the 5-day maximum guideline established by NRC Enforcement Manual Appendix F, Notices of Enforcement Discretion. The remaining subsections of this enclosure provide additional information addressing how the criteria in Appendix F of the NRC Enforcement Manual are met.

The only alternative to this request for enforcement discretion is to shut down Fermi 2 by 1600 EDT on June 3, 2023. A shutdown of Fermi 2 is undesirable at this time and does not provide a corresponding health and safety benefit based on risk assessments that have been performed.

2. Did the licensee provide a description of the TSs or other license conditions that will be violated? This description shall include the time the condition was entered and when the completion time will expire.

Fermi 2 is currently in Mode 1 (power operation) operating at 100% power and has been in Mode 1 for approximately 11 months. In Modes 1, 2, and 3, the Fermi 2 TS 3.7.2, Emergency Equipment Cooling Water (EECW) /Emergency Equipment Service Water (EESW) System and Ultimate Heat Sink (UHS), requires two EECW/EESW subsystems and UHS be operable.

When one or more are inoperable, as is the case with this request, TS 3.7.2 the following Condition applies:

  • B.1 - Restore the EECW/EESW subsystem to OPERABLE status.

to NRC-23-0039 Page 3 If Required Action B.1 cannot be completed within its 72-hour Completion Time, then TS 3.7.2 Condition C applies. Condition C contains two Required Actions, C.1, to be in Mode 3 with a Completion Time of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and C.2, to be in Mode 4 with a Completion Time of 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.

In the current condition, the issue with the EECW subsystem resulted in entry to TS 3.7.2 Condition B at 0400 EDT on May 31, 2023. As a result, the Completion Time for Required Action B.1 will expire at 0400 EDT on June 3, 2023. The repair to the EECW heat exchanger cannot be implemented before that time, therefore placing the plant in Mode 3 would be required by TS 3.7.2 Condition B by 1600 EDT on June 3, 2023.

With one EECW/EESW subsystem inoperable for reasons other than Condition A, the EECW/EESW subsystem must be restored to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. With the unit in this condition, the remaining OPERABLE EECW/EESW subsystem is adequate to perform the heat removal function. However, the overall reliability is reduced because a single failure in the OPERABLE EECW/EESW subsystem could result in loss of EECW/EESW function. The 72-hour Completion Time is based on the redundant EECW/EESW System capabilities afforded by the OPERABLE subsystem and the low probability of an accident occurring during this time period.

3. Did the licensee provide sufficient information to demonstrate that the cause of the situation is well understood including extent of condition on other related SSCs (e.g.,

common cause)?

Troubleshooting Process The following troubleshooting steps were performed:

  • P4400B001C (EECW Division 1 Backup Heat Exchanger) was placed in service at 0030 on 6/1/2023, D/P trend was 10.73 psid.
  • EESW pump cycling was performed to provide additional debris which resulted in a 0.4 psid D/P drop.
  • P4400B001A (Division 1 EECW Heat Exchanger) was dissembled and inspected. Ferrous material was found restricting flow through the heat exchanger.

Additional troubleshooting was performed by review of site procedures, validating that there was not a failure of M&TE along with validating that there were not DP errors during the surveillance.

Cause The direct cause of failing the 24.208.02 Section 5.1, EESW Pump and Valve Operability Test -

Division 1 is due to the clogging of the P4400B001A with ferrous material. The source of the ferrous material is being evaluated but assumed to be recently installed underground service to NRC-23-0039 Page 4 water piping. By performing the actions noted above it has been proven that the majority of the material has been removed from the system.

Common Cause This issue is isolated to the Division 1 EECW heat exchangers. Division 2 EECW Heat exchangers have been monitored and do not show signs of fouling or adverse trends. Division 2 heat exchanger P4400B001B has been in service since 2020 and was tested in March and December. The P4400B001D heat exchanger is currently in service and as of March measured D/P 9.2 psid.

4. Did the licensee provide an evaluation of all safety and security concerns associated with operating outside of the TS or license conditions that demonstrates that the noncompliance will not create undue risk to the public health and safety or involve adverse consequences to the environment? This should include, as appropriate, a description of the condition and operational status of the plant, equipment that is out of service, inoperable, or degraded that may have risk significance, may increase the probability of a plant transient, may complicate the recovery from a transient, or may be used to mitigate the condition. This evaluation shall include potential challenges to offsite and onsite power sources and forecasted weather conditions.

System Description

The emergency equipment cooling water system (EECWS) provides a backup to the Reactor building closed cooling water system (RBCCWS) to cool essential equipment by transferring heat to the ultimate heat sink through the emergency equipment service water system (EESWS). It is designed to maintain this function in the event of seismic disturbance, loss of offsite power, or other site- or plant related events.

Equipment required for a safe shutdown of the reactor is cooled by the EECWS, which is cross connected to the RBCCWS for normal operation. The EECW is isolated and is cooled by the ultimate heat sink (RHR complex) for emergency operation. The EECWS is designed to Category I requirements.

In the event of a mechanical failure of the RBCCWS, high drywell pressure, or upon loss of offsite electrical power, the EECWS will start automatically (or may be manually initiated) to cool equipment needed for reactor shutdown. In addition, the EECWS may be used to augment RBCCW for the purpose of assisting in equipment cooling. The EECWS is cooled by the EESWS which is supplied by the RHR reservoir.

The EECW section of the RBCCWS consists of two redundant full-capacity loops, each with two (2) 100 percent capacity heat exchangers, pump, and makeup pump and tank. One heat exchanger is manually aligned for service. The second heat exchanger is provided as a backup.

The twin systems designated as Division I and Division II are cooled by the EESWS. The to NRC-23-0039 Page 5 EESWS, is powered off the essential buses and is designed to be redundant throughout. Upon loss of offsite power, high drywell pressure, or failure of the RBCCWS, both divisions of the EECWS are automatically activated; that is, pumps start, makeup tanks isolation valves open, and valves isolate the nonessential portion of the RBCCWS. The makeup tanks isolation valves do not start to open until the divisional isolation valves are closed. Upon loss of RBCCWS differential pressure between the supply and return headers, either Division I and/or Division II EECW loops will start automatically, depending on the portion of the RBCCWS affected. The EECWS may also be manually initiated.

The EECW heat exchangers are a plate-and-frame design to increase the nominal heat transfer capability. The design analyses that define minimum EECW heat exchanger thermal performance consider the potential effects of initial plugging and plugging rate to establish the thermal performance and heat exchanger differential pressure vs. flow test criteria necessary to ensure the accident mission can be accomplished with credit for only one of the two identical units provided in each division. Once the maximum allowed normal operating plugging limit on a unit is reached, the EECW and EESW flows may be aligned to the clean spare heat exchanger in each division; thereby facilitating maintenance without interrupting normal plant operation.

Plant Condition and Operational Status Fermi 2 is Currently in Mode 1, 100% power and current Probabilistic Safety Analysis is green.

Division 1 EECW/EESW is inoperable with the associated supported equipment inoperable tracked on LCO 2023-0120:

  • TRM 3.6.8 Drywell Spray
  • TRM 3.7.7 Appendix R Alternative Shutdown Auxiliary Systems Additionally, the following are being tracked on being tracked on Safety Function Determination sheet with the MOST (Max Out of Service Time) applied:

o Condition C - One CSS subsystem inoperable AND One LPCI subsystem inoperable.

  • TS 3.6.2.3 Suppression Pool Average Temperature o Condition A - One RHR suppression pool cooling subsystem inoperable
  • TS 3.8.7 Distribution Systems -Operating to NRC-23-0039 Page 6 o Condition A - One or more required AC electrical power distribution subsystems inoperable o Condition B - One or more required DC electrical power distribution subsystems inoperable
  • TS 3.7.4 Control Center Air Conditioning (AC) System o Condition A - One control center AC subsystem inoperable.

All equipment remains available and capable of functioning and there are no inoperable SSCs in the redundant trains.

Current equipment challenges in the plant include:

  • Packing leak from E4150F003 (HPCI steam inlet outboard isolation). This leak does not challenge HPCI system operability nor its availability. The steam leak is in the RB steam tunnel, this area is cooled by the steam tunnel coolers which are cooled by RBCCW only, so no impact due to Division 1 EECW inoperable.
  • Main Unit Transformer 2A (Main Generator Step-up) cooling (high oil temp) - currently oil temperatures are stable and there is 10-15degrees C margin to a required load reduction and ~30 degrees C margin to de-energize the transformer which would require plant shutdown. There are compensatory actions (monitoring 3x/shift) and augmented cooling fans per plant procedures. Division 1 EECW inoperability does not impact this challenge.

Offsite Power Sources All offsite power sources are currently operable and are being supplied to both the 120 kV and 345 kV switchyards from the transmission network by five transmission lines.

Onsite Power Sources All onsite power sources (EDGs 11-14 & CTG11-1) remain operable.

Weather Conditions There is no forecasted threat for thunderstorms, high winds nor tornadic activity that challenge onsite/offsite power sources in the next 5 days. There is a potential for mayflies based current MET data and lake temperatures. This has been mitigated by 27.322 (Mayfly Infestation Preparation) and the near blackout condition at the site. No mayflies have been seen onsite thus far. Grid stability/load is dependent on temperatures and available generation. MISO (Midcontinent Independent System Operator) has declared a Maximum Generation Capacity Advisory from 6/2/2023 at 0700 until further notice.

The weather forecast from the National Weather Service for the area for the duration of the enforcement discretion is as follows:

to NRC-23-0039 Page 7

  • Saturday (6/3/2023): Mixture of sun and clouds, with a high near 88F. Winds ENE at 10-15 mph. Chance of precipitation is 15%.
  • Saturday night: Mostly clear with a low around 59F. Winds E at 10-15 mph. Chance of precipitation is 10%.
  • Sunday (6/4/2023): Sunny with a few passing clouds, high near 82F. Winds NE 5-10 mph. Chance of precipitation is 0%.
  • Sunday night: Partly cloudy skies, with a low around 59F. Winds SSE at 5-10 mph.

Chance of precipitation is 1%.

  • Monday (6/5/2023): Partly cloudy in morning and then cloudy in afternoon with possibility of stray shower or thunderstorm. High near 82F. Winds N at 10-15 mph.

Chance of precipitation is 15%.

  • Monday night: A few clouds from time to time, with a low around 54F. Winds N at 10-15 mph. Chance of precipitation is 13%.
  • Tuesday (6/6/2023): Intervals of clouds and sunshine, high near 77F. Winds NNE 10-20 mph. Chance of precipitation is 1%.
  • Tuesday night: Clear skies, with a low around 52F. Winds N 10-20 mph. Chance of precipitation is 0%.
  • Wednesday (6/7/2023): Mostly sunny skies, with a high near 76F. Winds N at 10-15 mph. Chance of precipitation is 2%.
  • Wednesday night: A few clouds from time to time, with a low around 53F. Winds N at 10-15 mph. Chance of precipitation is 3%.

Based on the forecasted weather, there is a low probability that severe weather could impact offsite power sources or delay the completion of the maintenance activities. This request for enforcement discretion is not in regard to severe weather or natural phenomena-related emergencies.

Repairs The request for the Notice of Enforcement discretion includes the successful completion of the EESW Pump and Valve Operability Test - Division 1 surveillance test using the P4400B001A (Division 1 EECW Heat Exchanger), along with the completion of the cleaning of the P4400B001C (EECW Division 1 Backup Heat Exchanger) to provide the alternate back-up to P4400B001A. This additional maintenance is expected to be completed 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> after the original LCO completion time. Although, it has been demonstrated that the material has been removed from the system, this will ensure sufficient margin exists.

Environmental Considerations Although the proposed action involves noncompliance with the requirements of a TS LCO:

to NRC-23-0039 Page 8

  • There is no significant change in the types or a significant increase in the amounts of any effluent that may be released offsite, since the proposed actions neither affect the generation of any radioactive effluent nor do they affect any of the permitted release paths; and
  • There is no significant increase in individual or cumulative occupational radiation exposure. The actions proposed in this request for enforcement discretion will not significantly affect plant radiation levels, and therefore do not significantly affect dose rates and occupational exposure.

As a result, no adverse consequences to the environment will occur.

No Undue Risk to the Public Health and Safety The requested enforcement discretion will not result in more than a minimal increase in risk, as demonstrated in the risk discussion in a subsequent subsection later in this enclosure. There are no foreseen challenges to the available offsite and onsite power sources. Measures have been implemented to prevent any maintenance activities on systems in the plant that could impact the division 2 safety systems. There is no significant increase in radiological risk by applying enforcement discretion to the TS 3.7.2, Condition B Completion Time to accomplish the required repairs. Appropriate plant redundant and support systems (i.e., including non-TS equipment) will be considered as protected systems to ensure there is no undue risk of redundant or support equipment inoperability during the duration of the proposed enforcement discretion.

Conclusion Based on the above response, the enforcement discretion for the TS 3.7.2, Condition B Completion Time will not create undue risk to the public health and safety or involve adverse consequences to the environment. In addition, MISO (Midcontinent Independent System Operator) has declared a Maximum Generation Capacity Advisory from 6/2/2023 at 0700 until further notice.

5. Did the licensee provide a description and timeline of the proposed course of action to resolve the situation (e.g., likely success of the repairs) and explain how the resolution will not result in a different or unnecessary transient? This shall include the time period for the requested discretion and demonstrate a high likelihood of completion within the requested period of enforcement discretion. If the proposed course of action necessitates enforcement discretion greater than 5 days, the licensee shall justify why a longer-term solution (e.g., emergency amendment) should not be processed within the duration of a 5 days NOED.

The request for the Notice of Enforcement discretion includes the successful completion of the EESW Pump and Valve Operability Test - Division 1 surveillance test using the P4400B001A Heat exchanger, along with the completion of the cleaning of the P4400B001C Heat Exchanger to provide the alternate back-up to the P4400B001A heat exchanger and a potential 2nd cleaning of the P4400B001A Heat Exchanger depending on results of the 6/2/2023 testing. This to NRC-23-0039 Page 9 additional maintenance is expected to be completed 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> after the original LCO completion time. Although it has been demonstrated that the material has been removed from the system, this will ensure sufficient margin exists.

The mission time for the EECW Heat Exchangers is 100 days, this timeline above provided the reasonable assurance that one of the two Heat Exchangers will meet the Technical Specification operability requirement and the other backup would be available to put in service if additional debris accumulation to occur.

6. Did the licensee detail and explain compensatory actions the plant has both taken and will take to reduce risk(s), focusing on both event mitigation and initiating event likelihood? This shall include how each compensatory measure achieves one or more of the following:
a. Reduces the likelihood of initiating events;
b. Reduces the likelihood of the unavailability of redundant trains, during the period of enforcement discretion; and
c. Increases the likelihood of successful operator actions in response to initiating events.

Compensatory Actions Taken Protected equipment postings are deployed per plant procedures due to Division 1 EECW/EESW inoperable:

  • Division 2 EECW/EESW,
  • Division 2 Switchgear,
  • Division 2 Stand-by Gas Treatment System,
  • Division 2 Control Center HVAC,
  • Division 2 Batteries and battery chargers

Compensatory Actions That Will be Taken There are no additional compensatory measures to further prepare Operations to respond to initiating events.

to NRC-23-0039 Page 10

7. Did the licensee demonstrate that the NOED condition, including compensatory measures will not result in more than a minimal increase in radiological risk, either in quantitative assessment that the risk will be within the normal work control levels (ICCDP less than or equal to 5E-7 and/or ICLERP less than or equal to 5E-8) or in a defensible qualitative manner?

The risk associated with operating the plant with both Division 1 Emergency Equipment Cooling Water (EECW) Heat Exchangers (P4400B001A/C) unavailable in support of repairs to an EECW Division 1 Heat Exchanger for a period of up to five days for enforcement discretion was found to meet the thresholds of NRC Enforcement Manual Appendix F. To augment this evaluation, risk will be minimized during the proposed period of enforcement discretion by protecting equipment in accordance with MOP05-100, Protected Equipment and ODE20, Protected Equipment. These compensatory measures will be in effect prior to entry into the period of the proposed enforcement discretion.

See Attachment 1 for more details.

8. Did the licensee confirm that the facility organization that normally reviews safety issues has reviewed and approved this request and that a written NOED request will be submitted within 2 days of the NRC staffs decision regarding the NOED?

This request for enforcement discretion has been reviewed and approved by the Fermi 2 Onsite Review Organization (OSRO) on June 2, 2023. This letter fulfills the requirement that a written NOED request be submitted by DTE within 2 days of the NRC staffs decision.

In addition, DTE has considered whether it is appropriate for a follow-up license amendment to be submitted under 10 CFR 50.90 following this NOED. At this time, DTE has not identified a need for such a follow-up license amendment request.

References

1. Nuclear Regulatory Commission Enforcement Manual, Appendix F, Notices of Enforcement Discretion, dated October 1, 2019 (ML19193A003)

TECHNICAL EVALUATION COVERSHEET TE Number: TE-P44-23-042 Revision: 1 Page 1 of 11 Initiating Document: Affected System/PIS number(s):

CR-2023-30619 P4400

Title:

Risk Evaluation for Notice of Enforcement Discretion Regarding Division 1 EECW Abstract:

The purpose of this technical evaluation is to assess the core damage and large early release risk associated with operating the plant with both Division 1 EECW Heat Exchangers (P4400B001A/C) unavailable in support of repairs to an EECW Division 1 Heat Exchanger for a period of up to five days for enforcement discretion. This evaluation also addresses risk insights from the Probabilistic Risk Assessment (PRA) model regarding dominant risk contributors and compensatory measures to be taken during the proposed period of enforcement discretion.

Continued Conclusions/Restrictions:

The risk associated with operating the plant with both Division 1 Emergency Equipment Cooling Water (EECW) Heat Exchangers (P4400B001A/C) unavailable in support of repairs to an EECW Division 1 Heat Exchanger for a period of up to five days for enforcement discretion was found to meet the thresholds of NRC Enforcement Manual Appendix F. To augment this evaluation, risk will be minimized during the proposed period of enforcement discretion by protecting equipment in accordance with MOP05-100, Protected Equipment and ODE20, Protected Equipment. These compensatory measures will be in effect prior to entry into the period of the proposed enforcement discretion.

Continued Preparer (Print/Sign) Qualification: PSA-01/PSA-09 6.2.3.5)

N/A (refer to Step Kasi Rhodes / See Attached Email Date: 06/02/23 Reviewer (Print/Sign) Qualification: PSA-01/PSA-09 N/A (refer to Step 6.2.6.8)

Mickey Koenemann / See Attached Email Date: 06/02/23 ITPR (Print/Sign) ~ N/A

/ Date:

Approver (Print/Sign)

Michael Lake / See Attached Email Date: 06/02/23 Human Performance and MES56 "Pre-Screen" MES56001 provided with Tech Evaluation* ~ , Full MES56 Risk Review: Required Optional

~

(*MES56001 not required to be attached to Tech Evaluation, only available for Supervisor review and to ensure it will be forwarded to HUDC in accordance with MES56)

Work Planner Acknowledgement (Print/Sign) ~ N/A

/ Date:

DTC: TDEVAL DSN: TE-P44-23-042 Rev: 1 File: 1803.01 IP: I ISFSI Related Yes No Date: 06/02/2023 DTC: TPMMES DSN: MES58001 Rev. 5 P1/1 IP: I File:1703.22 Issued: 1/12/2022 TE-P44-23-042 Revision 1 Page 2 of 11 A. Purpose The purpose of this technical evaluation is to assess the core damage and large early release risk associated with operating the plant with both Division 1 EECW Heat Exchangers (P4400B001A/C) unavailable in support of repairs to an EECW Division 1 Heat Exchanger for a period of up to five days for enforcement discretion. This evaluation also addresses risk insights from the Probabilistic Risk Assessment (PRA) model regarding dominant risk contributors and compensatory measures to be taken during the proposed period of enforcement discretion.

B. Quantitative Risk Evaluation This section details a quantitative risk evaluation performed for the purpose of comparing Incremental Conditional Core Damage Probability (ICCDP) and Incremental Conditional Large Early Release Probability (ICLERP) of the plant condition with the thresholds set forth in the NRC Enforcement Manual Appendix F (EM APP F) [1].

ICCDP and ICLERP are determined from Equation 1 and Equation 2, respectively:

ICC DP = ( CDFdeg - CDFbase) x CT Equation 1 ICLERP = (LERFdeg - LERFbase) x CT Equation 2 Where CDFdeg is the Core Damage Frequency in the degraded plant configuration CDFbase is the CDF baseline value with no degraded equipment or equipment unavailable due to maintenance LERFdeg is the Large Early Release Frequency in the degraded plant configuration LERFbase is the LERF baseline value with no degraded equipment or equipment unavailable due to maintenance CT is the additional time requested for enforcement discretion In accordance with EM APP F, risk of the plant-specific configuration the plant intends to operate in during the period of enforcement discretion was quantified. The degraded plant configuration reflects the following equipment that is currently unavailable:

  • Main Steam Drain Line Inboard Isolation Valve (B2103F016)
  • Main Steam Drain Line Outboard Isolation Valve (B2103F019)
  • Emergency Hotwell Supply Pump (P1100C001B)1
  • Division 1 EECW Heat Exchanger (P4400B001A)
  • Division 2 EECW Heat Exchanger (P4400B001B)
  • Division 1 EECW Backup Heat Exchanger (P4400B001C)
  • Station Air West Receiver Tank (P5001A002)
  • CTG 11-2 (R1100S070)

The following are the additional relevant assumptions for the calculation:

1. Per EM APP F, the zero maintenance PRA model, FermiV12 [2], was utilized to perform the assessment.

1 The Emergency Hotwell Supply Pump (P1100C001B) was returned to service prior to issuance of this Technical Evaluation, but its unavailability is conservatively included in the calculations.

TE-P44-23-042 Revision 1 Page 3 of 11

2. Calculations were performed with a 1E-12/yr truncation limit for CDF and a 5E-13/yr truncation limit for LERF.
3. The Fermi 2 internal events PRA has been peer reviewed against Regulatory Guide 1.200, Revision 2. All findings are closed and non-Capability Category II supporting level requirements have been addressed and resolutions are incorporated into the current model of record, FermiV12.

Table 1 contains the results of the FermiV12 Internal Events Quantification along with the resulting ICCDP and ICLERP values for comparison with the EM APP F thresholds. The conversion factor used to convert days to years is 365.25 days/year.

Table 1: Summary of Quantification Results and Risk Calculation Base [/yr] Degraded [/yr] Proposed CT [days] ICCDP/ ICLERP CDF 1.68E-06 2.59E-06 5 1.25E-08 LERF 5.02E-07 6.87E-07 5 2.53E-09 The EM APP F thresholds are :S 5.0E-7 for ICCDP and :S 5.0E-8 for ICLERP. As shown in Table 1, these thresholds are met for a proposed completion time of up to five days.

C. Dominant Risk Contributors The following are Fermi specific design features that enhance Fermis ability to successfully mitigate most initiating events.

1. Fermi has two physically and electrically independent sources of Offsite power (120 kV and 345 kV lines). These offer the site greater electrical redundancy.
2. Fermi has two EDGs (Emergency Diesel Generators) per Division
3. Fermi has four CTGs, one of which is self-black start capable. The other three are capable of black start with the assistance of a black start diesel generator. The CTGs normally provide power to Division 1 loads, and the PSA model credits operator action to crosstie to Division 2.
4. Fermi has a high pressure inventory makeup system Standby Feedwater (SBFW), in addition to HPCI (High Pressure Coolant Injection) and RCIC (Reactor Core Isolation TE-P44-23-042 Revision 1 Page 4 of 11 Cooling). SBFW is a motor driven system which can also be utilized at low reactor pressures (can be powered by any of the four CTGs (Combustion Turbine Generators.))

The dominant CDF initiating event contributors that increased with unavailability of Division 1 EECW are:

  • Large LOCA Below Top of Active Fuel (TAF) - Water
  • Medium LOCA Below TAF - Water These initiating events contributions to the CDF increased by factors of 5.26, 5.24, 4.44, 3.04, and 2.23, respectively.

While still significant contributors, the following initiating events contributions to the CDF decreased due to the unavailability of Division 1 EECW:

  • Major Rupture in Fire Protection System Line in Reactor Building that Propagates to Division 1/2 Core Spray and Division 1 RHR Areas
  • Major Rupture in Fire Protection System Line in Auxiliary Building that Propagates to the HPCI Room
  • Major Rupture in Fire Protection System Line in Reactor Building or Auxiliary Building that Propagates to Division 1 Core Spray Area
  • Major Rupture in Fire Protection System Line in Auxiliary Building that Propagates to HPCI Room and Division 1 Core Spray Area
  • Nominal Rupture in Fire Protection System Line in Auxiliary Building that Propagates to HPCI Room and Division 1 Core Spray Area
  • Nominal Rupture in Fire Protection System Line in Auxiliary Building Division 1 Switchgear Room These initiators contributions to CDF decreased by 7%, 7%, 4%, 4%, 2%, and 1%, respectively.

The dominant LERF initiating event contributors present with unavailability of Division 1 EECW are:

  • Nominal Rupture in Reactor Building Division 2 CCW/EECW Line in Reactor Building that Propagates to Division 1/2 RHR Areas
  • Major Rupture in Reactor Building Division 2 CCW/EECW Line in Reactor Building that Propagates to Division 1/2 RHR Areas
  • Major Rupture in General Service Water Line in Auxiliary Building RBCCW Heat Exchanger Room
  • Small LOCA Below TAF - Water TE-P44-23-042 Revision 1 Page 5 of 11 These initiating events contributions to the LERF increased by factors of 23.88, 23.14, 6.26, 3.90, 2.93, and 2.01, respectively.

While still significant contributors, the following initiating events contribution to LERF decreased due to the unavailability of Division 1 EECW:

  • Major Rupture in Fire Protection System Line in Reactor Building that Propagates to the Division 2 Core Spray Area This initiators contribution to LERF decreased by 16%.

The dominant risk contributors found in the cutsets containing Division 1 EECW unavailable are failures of Division 2 EECW/EESW Pumps and/or Valves.

The aforementioned changes in risk contributions have been evaluated and the compensatory actions listed in Section D have been deemed adequate.

D. Compensatory Measures In accordance with MMR12 Equipment Out of Service Risk Management [3], the plant is currently in a LOW risk status and will remain in this category for the NOED period. The following equipment protections will be in effect in accordance with MOP05-100 Protected Equipment [4] and ODE-20, Protected Equipment, [5] until the Division 1 EECW System is restored:

1. Elective maintenance will not be performed on the following Division 2 Systems:
  • Switchgear
  • Control Center Heating, Ventilation, and Air Conditioning (CCHVAC)
  • Batteries and Battery Chargers
2. Restricted access to all previously stated systems
3. Signage defining systems under protection both within and when entering protected area
4. Operations will brief on risk-significant actions Further, mitigating actions are in place to prevent mayflies from impacting onsite/offsite power sources.

TE-P44-23-042 Revision 1 Page 6 of 11 While in the proposed period of enforcement discretion, overall plant risk will be managed by the existing Configuration Risk Management Program (CRMP). This program evaluates increases in risk posed by potential combinations of equipment out-of-service and potential increases in initiating event frequency and requires that risk management actions be implemented as appropriate for a given plant configuration. Maintenance and testing during the allowed outage time extension will be rescheduled for Fermi 2 as warranted to minimize aggregate risk.

This will specifically include work performed on safety significant systems and their applicable support systems. No quantitative credit was taken in the evaluation for the implementation of the compensatory measures.

E. Extent of Condition Each division of the EECW System has two 100% capacity heat exchangers. As stated in Section B, both Division 1 Heat Exchangers (P4400B001A/C) and one Division 2 (P4400B001B) are currently out of service. To address a Common Cause Failure (CCF) on the Division 2 EECW Heat Exchanger (P4400B001D), the probability of the CCF basic event (HXPFECWSCC22_1) was increased to 2.87E-02 [6] in accordance with the methodology outlined in the NRC Risk Assessment of Operational Events Handbook [7]. The ICCDP and ICLERP with this increased CCF probability were 3.18E-08 and 3.46E-09, respectively, for a proposed completion time of up to five days. These values meet the thresholds listed in Section B.

F. External Event Risk To fully characterize the risk presented by this condition, an assessment should be performed on external event factors that could impact safety during the period of enforcement discretion. Fermi 2 has developed an Other External Hazards (OEH) Screening Report to determine the applicability of various external events to Fermi 2. The result of the screening report was that only internal flooding, internal fire and seismic hazards require detailed PRAs.

Internal flooding is already included in the Fermi 2 internal events model.

A peer review of the Fermi 2 OEH Screening Report was conducted in May 2014 by industry peers under the auspices of the Boiling Water Reactor Owners Group (BWROG). The peer review report shows details of the Facts and Observations (F&Os) that were written as a result of this assessment. The report found that all supporting requirements meet Capability Category I/II/III of the ASME/ANS standard. All findings from this peer review have subsequently been closed. As only fire and seismic hazards were identified as necessary, no further external hazards need to be evaluated for this application.

Discussion of Risk Insights from Internal Fires Unscreened Fire Areas From the Fermi 2 IPEEE [8], which employed a FIVE methodology, six unscreened fire areas were shown to be risk significant. These are shown below in a reproduction of Table 4-14 of the IPEEE:

TE-P44-23-042 Revision 1 Page 7 of 11 Unscreened Fire Areas Fire Area Description nd RB06 Reactor Building 2 Floor 03AB Relay Room 04ABN Division 1 Switchgear Room 09AB Control Room 11ABE Div. 1 Portion Miscellaneous Room 12AB Division 2 Switchgear Room Each of the compartments is discussed below in the context of the current plant configuration to develop risk-informed insights for fire hazards. The goal of this analysis is to evaluate fires that preferentially impact Division 2 EECW and rely upon the Division 1 counterparts of these systems for achieving safe shutdown.

RB06:

From Section 4.3.1.4.5 of the IPEEE, dominant fires in this area lead to core damage due to their impact on bus 72CF, which impacts both divisions of LPCI. Core damage sequences for these fires are dominated by random failure of the torus cooling injection valves. In addition, some scenarios in this fire area can result in failure of Division 1 RHR and the Torus Hardened Vent.

As these dominant fires do not impact Div 2 EECW no fire risk management actions are required in this area.

03AB:

Section 4.3.1.4.1 of the IPEEE describes the dominant core damage scenarios for fires in the relay room. The dominant fires in this area cause depressurization and loss of one division of RHR for heat removal. In addition, some scenarios in this fire area can result in failure of Division 1 RHR and the Torus Hardened Vent. As these dominant fires do not impact Div 2 EECW no fire risk management actions are required in this area.

04AB:

Section 4.3.1.4.2 of the IPEEE states that dominant core damage contributors in the Division 1 Switchgear Room involve severe degradation of Division 1 decay heat removal capability. In addition, some scenarios in this fire area can result in failure of Division 1 RHR and the Torus Hardened Vent. As these dominant fires do not impact Div 2 EECW no fire risk management actions are required in this area.

09AB:

From Section 4.3.1.4.3 of the IPEEE, the most severe fire in the control room is a fire in panel H11P602, which defeats all Division 2 ESF systems and results in core damage due to random failure of standby feedwater and Division 1 low pressure injection systems. As this dominant fire would impact Div 2 EECW fire risk management actions were considered. This zone is continually manned and any fire would immediately be recognized and addressed. As such, fire risk management actions are not required.

11ABE:

The most severe fires mentioned, from Section 4.3.1.4.4 of the IPEEE, in the DC MCC area are those that affect Division 1 DC and would rely upon Division 2 systems, including for decay TE-P44-23-042 Revision 1 Page 8 of 11 heat removal. As these dominant fires do not impact Div 2 EECW no fire risk management actions are required in this area.

12AB:

This fire area is the divisional opposite of 04ABN. Because fires in this area defeat Division 2 systems, this area was considered for fire risk management actions. As these dominant fires do not impact Div 2 EECW no fire risk management actions are required in this area.

In addition, Division 2 of EECW does not fall within the fire (a)(4) program as described in MMR12 Equipment Out of Service Risk Management. This indicates it is not a major contributor to fire core damage risk and does not require fire risk management actions.

Discussion of Risk Insights from Seismic Hazards Seismic events are those that are likely to lead to core damage by causing a loss of offsite power.

As such, existing measures to protect Division 2 EDGs and Division 2 EECW are considered prudent measures to reduce the risk of seismic events during the period of proposed enforcement discretion.

G. Conclusion The risk associated with operating the plant with both Division 1 EECW Heat Exchangers (P4400B001A/C) unavailable in support of repairs to an EECW Division 1 Heat Exchanger for a period of up to five days for enforcement discretion was found to meet the thresholds of NRC EM APP F. To augment this evaluation, risk will be minimized during the proposed period of enforcement discretion by implementation of the compensatory measures described in this evaluation. These compensatory measures will be in effect prior to entry into the period of the proposed enforcement discretion.

H. References

[1] NRC Enforcement Manual Appendix F, "Notices of Enforcement Discretion", 2019.

[2] TMSA-21-0001, Documentation of the Release of PSA Model FermiV12", 2021.

[3] MMR12 "Equipment Out of Service Risk Management", Revision 20A, 2019.

[4] MOP05-100 "Protected Equipment" Revision 2C, 2018.

[5] ODE-20, "Protected Equipment" Revision 29, 2023.

[6] EF2-PRA-010, "Fermi 2 Nuclear Power Station PRA Component Data Notebook, VOL 2, 2021.

[7] NRC Risk Assessment of Operational Events Handbook, VOL I - Internal Events, Revision 2.01, 2017.

[8] TMSA-10-0010, "Fermi 2 Individual Plant Examination for External Events (IPEEE)",

2010.

TE-P44-23-042 Attachment 1 Revision 1 Page 9 of 11 Kasi Rhodes From: Kasi Rhodes Sent: Friday, June 2, 2023 3:40 PM To: Kasi Rhodes Cc: Michael Lake; Mickey Koenemann

Subject:

TE-P44-23-042 Preparer Signature This email serves as my approval to sign the following documents electronically as PREPARER for the following document and should be attached for vaulting purposes:

DSN Revision DTC Date TE-P44-23-042 1 TDEVAL 06/02/2023 I have verified my qualification to PSA-01 and PSA-09 as required per MMR12 for this task prior to sending this email.

Thank you, KASI RHODES M R UL E & P S A E NG I NE E R Enrico Fermi Atomic Power Plant l Newport, MI 734.586.4165 l kassandra.rhodes@dteenergy.com This communication may contain privileged or confidential information protected by legal rules. It is solely for the use of t he intended recipient named above. Any review, dissemination, distribution, forwarding, or copying of this communication by someone other than the intended recipient, or the employee responsible for delivering this communication to the intended recipient, is prohibited. If you have received this communication in error, please immediately notify us by phone or reply to the sender via email, then destroy the original message. Thank you.

1

TE-P44-23-042 Attachment 1 Revision 1 Page 10 of 11 Kasi Rhodes From: Mickey Koenemann Sent: Friday, June 2, 2023 3:39 PM To: Kasi Rhodes

Subject:

TE-P44-23-042 Reviewer Signature This email serves as my approval to sign the following documents electronically as REVIEWER and should be attached for vaulting purposes:

DSN Revision DTC Date TE-P44-23-042 1 TDEVAL 06/02/2023 I have verified my qualification to PSA-01 and PSA-09 as required per MMR12 for this task prior to sending this email.

Michael Koenemann Lead PSA Engineer - Fermi 2 Remote - 734-625-4568 Michael.koenemann@dteenergy.com 1

Attachment 1 TE-P44-23-042 Revision 1 Kasi Rhodes Page 11 of 11 From: Michael Lake Sent: Friday, June 2, 2023 3:41 PM To: Kasi Rhodes Cc: Mickey Koenemann

Subject:

TE-P44-23-042 Approver Signature This email serves as my approval to sign the following documents electronically as APPROVER for the following document and should be attached for vaulting purposes:

DSN Revision DTC Date TE-P44-23-042 1 TDEVAL 06/02/2023 1

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