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LER-2015-006, Regarding Reactor Scram Due to Loss of Turbine Building Closed Cooling Water
Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(iv)(A), System Actuation; 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded; 10 CFR 50.73(a)(2)(viii)(A); 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition; 10 CFR 50.73(a)(2)(viii)(B); 10 CFR 50.73(a)(2)(iii); 10 CFR 50.73(a)(2)(ix)(A); 10 CFR 50.73(a)(2)(x); 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor; 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat; 10 CFR 50.73(a)(2)(v), Loss of Safety Function; 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown; 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications; 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability; 10 CFR 50.73(a)(2)(i); 10 CFR 50.73(a)(2)
	3412015006R01 - NRC Website
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Regarding Reactor Scram Due to Loss of Turbine Building Closed Cooling Water
	ML16109A091
Person / Time
Site:	Fermi
Issue date:	04/15/2016
From:	Polson K; DTE Electric Company, DTE Energy
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	NRC-16-0013 LER 15-006-01
	Download: ML16109A091 (16)
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Keith J. Polson Site Vice President DTE Energy Company 6400 N. Dixie Highway, Newport, MI 48166 Tel: 734.586.4849 Fax: 734.586.4172 Email: poIsonk@dteenergy.com DTE Energy-April 15, 2016 10 CFR 50.73 NRC-16-0013 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001 References: 1) Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43

2) DTE Electric Company Letter to the NRC, "Licensee Event Report (LER) No. 2015-006," NRC-15-0094, dated November 5, 2015 (ML15309A422)

Subject:

Licensee Event Reports (LERs) Nos. 2015-010 and 2015-011 and Supplement to LER No. 2015-006 Pursuant to 10 CFR 50.73 (a)(2)(iv)(A) and (a)(2)(v)(C), DTE Electric Company (DTE) is submitting the enclosed supplement to LER No. 2015-006, Reactor Scram Due to Loss of Turbine Building Closed Cooling Water. In addition, pursuant to 10 CFR 50.73 (a)(2)(iv)(A), DTE is submitting LER Nos. 2015-010, Manual Actuation of Reactor Core Isolation Cooling System due to a Leak in the Standby Feedwater System, and 2015-011, Reactor Protection System and Containment Isolation Actuation due to Reaching Reactor Water Level 3 Setpoint.

The supplement provides details that were not available for inclusion in Reference 2 and clarifies reporting of the Primary Containment isolation actuations.

LERs 2015-010 and 2015-011 were generated to separate out two events. These two events were included in LER 2015-006, Revision 0, rather than being reported as separate events per the guidance in NUREG-1022, Revision 3.

No commitments are being made in this LER.

USNRC NRC-16-0013 Page 2 Should you have any questions or require additional information, please contact Mr.

Alan I. Hassoun of my staff at (734) 586-4287.

Sincerely, Keith J. Polson Site Vice President

Enclosures:

1. Supplement to LER 2015-006, Reactor Scram Due to Loss of Turbine Building Closed Cooling Water

2. LER 2015-010, Manual Actuation of Reactor Core Isolation Cooling System Due to a Leak in the Standby Feedwater System

3. LER 2015-011, Reactor Protection System and Containment Isolation Actuation Due to Reaching Reactor Water Level 3 Setpoint cc:

NRC Project Manager NRC Resident Office Reactor Projects Chief, Branch 5, Region III Regional Administrator, Region III Michigan Public Service Commission Regulated Energy Division (kindschl@michigan.gov) to NRC-16-0013 Fermi 2 NRC Docket No. 50-341 Operating License No. NPF-43 Supplement to LER 2015-006, Reactor Scram Due to Loss of Turbine Building Closed Cooling Water

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 1031/2018 (11-2015)

Estimated burden per response to comply with this mandatory collection request:

80 hours9.259259e-4 days 0.0222 hours 1.322751e-4 weeks 3.044e-5 months .

Reported lessons learned are incorporated into the licensing process and fed back to industry.

t"

)Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by intemet e-mail to lnfocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and (See Page 2 for required number of Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid digits/characters for each block)

OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

3. PAGE Fermi 2 05000 341 1 OF 5

4. TITLE Reactor Scram Due to Loss of Turbine Building Closed Cooling Water

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR FACILITY NAME DOCKET NUMBER NUMBERNO.

N/A 05000 FACILITY NAME DOCKET NUMER 09 13 2015 2015 -

006 01 04 15 2016 N/A 05000

9. OPERATING MODE

11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 20.2201(b)

Q 20.2203(a)(3)(i) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(A) 1 El 20.2201(d)

El 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(B) 50.73(a)(2)(viii)(B) 20.2203(a)(1) 20.2203(a)(4) 50.73(a)(2)(iii)

Q 50.73(a)(2)(ix)(A) 20.2203(a)(2)(i) 50.36(c)(1)(i)(A)

/

50.73(a)(2)(iv)(A) 50.73(a)(2)(x)

10. POWER LEVEL 20.2203(a)(2)(ii) 50.36(c)(1)(ii)(A) 50.73(a)(2)(v)(A) 73.71(a)(4) 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(B) 73.71(a)(5) 20.2203(a)(2)(iv) 50.46(a)(3)(ii)

/

50.73(a)(2)(v)(C)

E 73.77(a)(1) 100 20.2203(a)(2)(v) 50.73(a)(2)(i)(A)

El 50.73(a)(2)(v)(D) 73.77(a)(2)(i) 20.2203(a)(2)(vi) 50.73(a)(2)(i)(B) 50.73(a)(2)(vii)

E 73.77(a)(2)(ii) 50.73(a)(2)(i)(C)

OTHER Specify in Abstract below or in The event reported in this LER was originally documented in LER 2015-006-00, submitted on November 5, 2015. This LER is prepared as a separate report since it was later determined that this event is not directly related to the manual reactor scram described in LER 2015-006-00, and should be reported in a separate LER based on the guidance specified in NUREG-1022, Revision 3.

Initial Plant Conditions

Mode: 3 Reactor Power: 0 percent The Reactor Coolant temperature and Reactor Pressure Vessel (RPV) ((RPV)) pressure prior to the event were 551 degrees Fahrenheit and 1021 psig, respectively.

Reactor Feed Pumps ((SJ)) were unavailable and Standby Feedwater (SBFW) ((SJ)) was non-functional at the start of the event. Since Reactor Feed Pumps and SBFW are a standard alternative means of controlling Reactor Water Level (RWL),

the unavailability of these components/systems is considered to have contributed to the initiation of this event.

Description of the Event At 0409 EDT on September 14, 2015, the Reactor Core Isolation Cooling (RCIC) ((BN)) system was placed in service to maintain RWL due to the SBFW system being declared non-functional. The SBFW system had been declared non-functional following the discovery of an unisolable leak in a weld associated with a SBFW drain valve ((V)) by a Radiation Protection Technician at 0405 EDT on September 14, 2015. Prior to that time, the SBFW system and Low-Low Set Safety Relief Valves (SRVs) ((RV)) were being used to maintain RWL and reactor pressure, respectively, in response to a manual reactor scram. The manual reactor scram event in response to a loss of all Turbine Building Closed Cooling Water (TBCCW) ((KB)) had occurred at 2305 EDT on September 13, 2015 as reported in LER 2015-006-01. SBFW was initiated at 2310 EDT on September 13, 2015. Following the manual actuation of RCIC, RWL and pressure were then controlled by the RCIC system and SRVs.

The manual actuation of the RCIC system is reportable under 10 CFR 50.73(a)(2)(iv)(A), as an event or condition that resulted in manual or automatic actuation of any of the systems listed in paragraph (a)(2)(iv)(B). An 8-hour follow-up notification to the original notification that reported the manual scram (No. 51391) was made to the NRC based on meeting the reporting criteria of 10 CFR 50.72(b)(3)(iv)(A) for RCIC initiation.

There were no radiological releases associated with this event.

Significant Safety Consequences and Implications

There were no significant safety consequences associated with this event. At no time during this event was there a potential for endangering the public health and safety.

The RCIC system was manually actuated to allow for remote manual operation to control flow that matches decay heat steam generation after shutdown. Therefore, no safety consequences were attributed to the manual actuation of RCIC.

The event reported in this LER was originally documented in LER 2015-006-00, submitted on November 5, 2015. This LER is prepared as a separate report since it was later determined that this event is not directly related to the manual reactor scram described in LER-2015-006-00, and should be reported in a separate LER based on the guidance specified in NUREG-1022, Revision 3.

Initial Plant Conditions

Mode: 3 Reactor Power: 0 percent The Reactor Coolant temperature and Reactor Pressure Vessel (RPV) ((RPV)) pressure prior to the event were 552 degrees Fahrenheit and 1027 psig, respectively.

There were no systems, structures, and/or components (SSCs) that were inoperable at the start of the event that contributed to the event.

Description of the Event At 1847 EDT on September 14, 2015, a valid automatic Reactor Protection System (RPS) ((JC)) actuation occurred due to Reactor Water Level (RWL) reaching Level 3. At the time, Operators were manually controlling RPV level and pressure with Reactor Core Isolation Cooling (RCIC) ((BN)) and Safety Relief Valves (SRVs) ((RV)). These Operator actions were in response to a manual reactor scram due to loss of all Turbine Building Closed Cooling Water (TBCCW) ((KB)) and subsequent non-functionality of Standby Feedwater (SBFW) ((SJ)) due to an unisolable leak in a weld, as reported in LERs 2015-006-01 and 2015-010-00, respectively. The loss of TBCCW also resulted in the closure of the Main Steam Isolation Valves (MSIVs) ((ISV)) due to degraded Instrument Air header pressure as discussed in LER 2015-006-01, such that MSIVs remained closed during this event. While Operators were cycling SRVs, the RPV level went below the Level 3 setpoint. Operators promptly restored RPV level by manual operation of RCIC. The Level 3 actuations and associated isolations were verified to occur as expected (Primary Containment Isolation Systems (PCIS) ((JM)) Groups 4, 13, and 15).

All control rods ((AC)) were already fully inserted. Following restoration of RPV level, Operators continued to control reactor water level and pressure by RCIC and SRVs.

The automatic RPS and containment isolation actuations due to RPV water Level 3 are reportable under 10 CFR 50.73(a)(2)

(iv)(A), as events or conditions that resulted in manual or automatic actuation of any of the systems listed in paragraph (a)

(2)(iv)(B), including reactor protection and containment isolation systems. An 8-hour follow-up notification to the original notification that reported the manual scram (No. 51391) was made to the NRC based on meeting the reporting criteria of 10 CFR 50.72(b)(3)(iv)(A) for manual or automatic system actuation.

There were no radiological releases associated with this event.

Significant Safety Consequences and Implications

There were no significant safety consequences associated with this event. At no time during this event was there a potential for endangering the public health and safety.

Initial Plant Conditions

Mode: 1 Reactor Power: 100 percent There were no structures, components, or systems that were inoperable at the start of the event that contributed to the event.

Description of the Event At 2305 EDT on September 13, 2015, a manual reactor scram was initiated in response to a loss of all Turbine Building Closed Cooling Water (TBCCW) ((KB)) in accordance with plant procedures. All control rods ((AC)) were fully inserted and the lowest Reactor Water Level (RWL) reached was 137 inches above Top of Active Fuel which is below the RWL Level 3 setpoint of 173 inches. Primary Containment Isolation Systems (PCIS) ((JM)) Groups 4, 13, and 15 associated with RWL Level 3 occurred as expected. Decay heat was initially being removed through the Main Turbine Bypass System

((JI)) to the Main Condenser ((COND)); however, as a result of the loss of TBCCW, the Reactor Feed Pumps ((SJ)) lost cooling and had to be secured. At 2310 EDT, the Standby Feedwater (SBFW) ((SJ)) system was initiated.

A field investigation later verified that a tube leak occurred in the East TBCCW heat exchanger ((HX)), causing General Service Water (GSW) to flow into the lower pressure TBCCW system. This resulted in a TBCCW head tank ((TK)) level increase and water flowing from the TBCCW head tank relief valve ((RV)). The interaction of TBCCW system pressure fluctuations with the TBCCW tank instrumentation ultimately caused a trip of the running TBCCW pumps and a loss of TBCCW.

The loss of TBCCW also caused all Station Air Compressors (SACs) ((CMP)) to trip on loss of cooling. The loss of SACs caused the Instrument Air header pressure to degrade to the point at which the Secondary Containment (SC) isolation dampers ((DMP)) drifted closed. This resulted in the Reactor Building ((NG)) pressure going positive and exceeding the Technical Specification minimum requirement of -0.125 inches water column. At 2325 EDT, Operators started the Standby Gas Treatment System (SGTS) ((BH)) and manually inserted a SC isolation signal. SC vacuum was restored to within Technical Specification limits. The Technical Specification limit was exceeded for approximately 3 minutes and 43 seconds and the maximum pressure recorded was 1.932 inches water column. Additionally, Operators were monitoring for expected Main Steam Isolation Valve (MSIV) ((ISV)) drift due to the degraded Instrument Air header pressure. When outboard MSIVs were observed to be drifting, Operators closed the outboard and inboard MSIVs at 2345 EDT. At 2352 EDT, Low-Low Set Safety Relief Valves (SRVs) ((RV)) reached their setpoint and began automatic cycling to control reactor pressure. The manual closure of MSIVs led to an expected loss of Condenser vacuum which resulted in the isolation of PCIS Group 1 at 0001 EDT on September 14, 2015.

The manual scram, Reactor Protection System (RPS) actuation due to reaching RWL Level 3, and the containment isolations are reportable under 10 CFR 50.73(a)(2)(iv)(A), as events or conditions that resulted in manual or automatic actuation of any of the systems listed in paragraph (a)(2)(iv)(B), including the RPS and containment isolation systems. A 4-hour event notification (No. 51391) was made to the NRC based on meeting the reporting criteria of 10 CFR 50.72(b)(2)(iv)

(B) and a follow-up notification was made for the 8-hour reporting criteria in 10 CFR 50.72 (b)(3)(iv)(A) for RWL Level 3 and containment isolations.

The event reported in this LER was originally documented in LER 2015-006-00, submitted on November 5, 2015. This LER is prepared as a separate report since it was later determined that this event is not directly related to the manual reactor scram described in LER 2015-006-00, and should be reported in a separate LER based on the guidance specified in NUREG-1022, Revision 3.