NRC-19-0071, Division 2 Mechanical Draft Cooling Tower Fan D Tripped When Placed in High Speed Due to a Blown Fuse

Division 2 Mechanical Draft Cooling Tower Fan D Tripped When Placed in High Speed Due to a Blown Fuse

ML19273A053
Person / Time
Site:	Fermi
Issue date:	09/30/2019
From:	Fessler P DTE Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NRC-19-0071
Download: ML19273A053 (5)

Text

Paul Fessler Senior Vice President and Chief Nuclear Officer DTE Energy Company 6400 N. Dixie Highway, Newport, MI 48166 Tel: 734.586.4153 Fax: 734.586.1431 Email: paul.fessler@dteenergy.com OTE September 30, 2019 10 CFR 50.73 NRC-19-0071 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001

Reference:

Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43

Subject:

Licensee Event Report (LER) No. 2019-004 Pursuant to 10 CFR 50.73(a)(2)(v)(D), DTE Electric Company (DTE) is submitting LER No. 2019-004, "Division 2 Mechanical Draft Cooling Tower Fan "D" Tripped when Placed in High Speed Due to a Blown Fuse."

No new commitments are being made in this LER.

Should you have any questions or require additional information, please contact Mr. Jason R. Haas, Manager - Nuclear Licensing, at (734) 586-1769.

Sincerely, Paul Fessler Senior Vice President and CNO

Enclosure:

Licensee Event Report No. 2019-004, "Division 2 Mechanical Draft Cooling Tower Fan "D" Tripped when Placed in High Speed Due to a Blown Fuse."

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(agmichigan.gov)

Enclosure to NRC-19-0071 Fermi 2 NRC Docket No. 50-341 Operating License No. NPF-43 Licensee Event Report (LER) No. 2019-004 Division 2 Mechanical Draft Cooling Tower Fan "D" Tripped when Placed in High Speed Due to a Blown Fuse

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 0313112020 (04-2018)

Estimated burden per response to comply with this mandatory collection request 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />.

Reported lessons learned are incorporated into the licensing process and fed back to A"

LICENSEE EVENT REPORT (LER)

Industry. Send comments regarding burden estimate to the Information Services Branch (T-2 F43), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by e-mail (See Page 2 for required number of digits/characters for each block) to Infocollects.Resource@nr.gov, and to the Desk Officer, Office of Information and (See NUREG-1022, R.3 for instruction and guidance for completing this form Regulatory Affairs EOB 0

-0an4ue tie of angetan detn Washingten, DC 20503. If a meane used to impose an information collection does not

'° http://ww.nrc.qov/reading-rm/do-collections/nureas/staff/sr1 022/r3/

display a currenty valid OMB control

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

1. Facility Name

2. Docket Number

3. Page Fermi 2 05000 341 1

OF 3

4. Title Division 2 Mechanical Draft Cooling Tower Fan "D" Tripped when Placed in High Speed Due to a Blown Fuse

5. Event Date

6. LER Number

7. Report Date

8. Other Facilities Involved Month Day Year Year Number No.

Month Day Year N/A DctNb Month DayiYear Year DecuentNambee 07 30 2019 2019 -

004 00 09 30 2019 N/A D5t00

9. Operating Mode

11. This Report is Submitted Pursuant to the Requirements of 10 CFR §: (Check all that apply) 1 20.2201(b)

E 20.2203(a)(3)(i)

E 50.73(a)(2)(ii)(A)

E 50.73(a)(2)(viii)(A)

E 20.2201(d)

E 20.2203(a)(3)(ii)

Q 50.73(a)(2)(ii)(B) 1 50.73(a)(2)(viii)(B) 1 Q

20.2203(a)(1)

E 20.2203(a)(4)

Q 50.73(a)(2)(iii)

E] 50.73(a)(2)(ix)(A)

Q 20.2203(a)(2)(i)

El50.36(c)(1)(i)(A)

El 50.73(a)(2)(iv)(A)

Q 50.73(a)(2)(x)

10. Power Level Q

20.2203(a)(2)(ii)

Ej 50.36(c)(1)(ii)(A) 0 50.73(a)(2)(v)(A)

El 73.71(a)(4)

']

20.2203(a)(2)(iii)

El 50.36(c)(2)

Q 50.73(a)(2)(v)(B)

El73.71(a)(5) 1 20.2203(a)(2)(iv)

E 50.46(a)(3)(ii)

E 50.73(a)(2)(v)(c) 73.77(a)(1) 100 20.2203(a)(2)(v)

Q 50.73(a)(2)(i)(A) 2 50.73(a)(2)(v)(D) 73.77(a)(2)(i) 20.2203(a)(2)(vi)

E] 50.73(a)(2)(i)(B)

E]50.73(a)(2)(vii) 73.77(a)(2)(ii)

Q 50.73(a)(2)(i)(C)

Q Other (Specify in Abstract below or in NRC Form 366A)

12. Licensee Contact for this LER Licensee Contact Telephone Number (Include Area Code)

Fermi 2 / Jason R. Haas - Manager, Nuclear Licensing (734) 586-1769

13. Complete One Line for each Component Failure Described in this Report Cause System Component Manufacturer Reportable to ICES Cause System Component Manufacturer Reportable to ICES X

BS FU N/A Y

N/A N/A N/A N/A N/A

14. Supplemental Report Expected Month Day Year

15. Expected Submission Date Yes (If yes, complete 15. Expected Submission Date)

/

No Abstract (Limit to 1400 spaces, i.e., approximately 14 single-spaced typewritten lines)

On July 30, 2019, at 1014 EDT, the Division 2 Mechanical Draft Cooling Tower (MDCT) Fan "D" was declared inoperable due to a trip of the fan while placing it in high speed. The MDCT Fans are required to support operability of the Ultimate Heat Sink (UHS). The UHS is required to support operability of the Division 2 Emergency Equipment Cooling Water (EECW) system. The EECW system cools various safety related components, including the High Pressure Coolant Injection (HPCI) system room cooler. An unplanned HPCI inoperability occurred based on a loss of the HPCI Room Cooler. The cause of the event was a blown high speed breaker control power fuse.

The control power fuse was replaced, the MDCT Fan "D" was tested satisfactorily, and HPCI was declared operable on July 30 at 1431 EDT. The blown fuse was quarantined and will be sent for failure analysis. The remaining fuses in the system are being replaced and sent to the vendor for comparison with the blown fuse.

NRC FORM 366 (04-2018)

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020 (04-2018)

Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported LICENSEE EVENT REPORT (LER) lessons learned are incorporated into the licensing process and fed back to industry. Send comments a

regarding burden estimate to the Information Services Branch (T-2 F43), U. S. Nuclear Regulatory CONTINUATION SHEET Commission, Washington, DC 20555-0001, or by e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of (SeeNUR G-122,R.3forinstucton nd uidncefor ompetig tis orm Management and Budget, Washington, DC 20503. It a means coed to impose an information (See NUREG-1022, R.3 for instruction and guidance for completing this form i

does not display a currently valid MB control number, the NRC may not conduct or htto://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/srl022/r3/

sponsor, and a person is not required to respond to, the information collection.

1. FACILITY NAME

2. DOCKET NUMBER

3. LER NUMBER YEAR SEQUENTIAL REV 05000-NUMBER NO.

Fermi 2 341 2019 -

04 00 NARRATIVE INITIAL PLANT CONDITIONS Mode 1 Reactor Power 100%

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

DESCRIPTION OF THE EVENT On July 30, 2019, at 1014 EDT, the Division 2 Mechanical Draft Cooling Tower (MDCT) [CTW] Fan [FAN] "D" was declared inoperable due to a trip of the fan when placing it in high speed during a Technical Specification Surveillance test. The MDCT Fans are required to support operability of the Ultimate Heat Sink (UHS) [BS]. The UHS is required to support operability of the Division 2 Emergency Equipment Cooling Water (EECW) system. The EECW system cools various safety related components, including the High Pressure Coolant Injection (HPCI) [BJ] system room cooler [CLR].

An unplanned HPCI inoperability occurred based on a loss of the HPCI Room Cooler. Investigation revealed that a high speed breaker control power fuse [FU] had blown. The control power fuse was replaced, the MDCT Fan "D" was tested satisfactorily, and the UHS and HPCI were declared operable on July 30, 2019 at 1431 EDT.

The HPCI system is a single train safety system.

The 10CFR50.72(b)(3)(v)(D) notification was made at 1542 on July 30, 2019 to the NRC Operations Center by Event Notification 54188.

This 10CFR50.73(a)(2)(v)(D) notification is fulfilling the 10CFR50.73 report requirement. Based on the equipment history of the MDCT fans and the cause of the failure being a blown fuse, there is no firm evidence to identify that the failure would have existed previously. Therefore, the failure is assumed to have occurred at the time of its discovery based on the guidance in NUREG-1022 Section 3.2.2.

SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS There were no safety consequences associated with this event. At no time during this event was there a potential for endangering the public health and safety. There were no radiological releases associated with this event.

Technical Specification 3.7.2 requires the UHS reservoir to be operable in Modes 1, 2, and 3. The UHS operability requirements in Modes 4 and 5 are determined by the systems the UHS supports. Each reservoir is the cooling source for that division's service water subsystems. A two-cell MDCT is located above each of the one-half capacity reservoirs.

Each cell is equipped with a MDCT fan. Two MDCT fans above each one-half capacity reservoir are required for that division of UHS to be considered operable. The "A" and "C" MDCT fans are in Division 1 and the "B" and "D" fans are in Division 2.

NRC FORM 366A (04-2018)

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NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 03/31/2020 (04-2018)

Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported LICENSEE EVENT REPORT (LER) lessons learned are incorporated into the licensing process and fed back to Industry. Send comments regarding burden estimate to the Information Services Branch (T-2 F43), U. S. Nuclear Regulatory CONTINUATION SHEET Commission, Washington, DC 20555-0001, or by e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of (See NUREG-1022, R.3 for instruction and guidance for completing this form Management and Budget, Washington, DC 20503. If a means used to impose en information collection does not display a currently valid 0MB control number, the NRC may not conduct or http://www.nrc.gov/reading-rm/doc-collections/nureqs/staff/srl022/r3/)

sponsor, and a person Is not required to respond to, the information collection.

1. FACILITY NAME

2. DOCKET NUMBER

3. LER NUMBER YEAR SEQUENTIAL REV 05000-NUMBER NO.

Fermi 3412019 004 00 NARRATIVE Since the Division 1 MDCT fans were unaffected, Division 1 of UHS and all of its supported equipment, including RCIC, were operable throughout this event. As a result, there was no loss of safety function associated with the UHS itself. The mission time associated with HPCI is less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. An engineering analysis has shown that use of a single MDCT fan in one division can achieve acceptable results for a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period for that division. The failure of MDCT Fan "D" only occurred at high speed and did not impact its ability to operate at low speed. The conditions present during this event, where Division 2 UHS had one operable MDCT fan (Fan "B") and a second MDCT fan operating at low speed (Fan "D")

were less challenging then the conditions utilized in the engineering analysis. Therefore, the short period of time where MDCT Fan "D" was only capable of operating at low speed would have had little or no impact on the functionality of HPCI.

CAUSE OF THE EVENT The fuse in location EF between points 1 and 2 for the MDCT Fan "D" high speed breaker 72 ED position 2B blew when the fan was shifted to high speed during the TS surveillance.

CORRECTIVE ACTIONS The fuse was replaced. The fan was then satisfactorily tested and the 52XX relay was confirmed to be energized following the test. The 52XX relay performed as expected for MDCT Fan "D" high speed breaker.

The blown fuse was quarantined and will be sent for failure analysis. The remaining fuses in the system are being replaced and will be sent to the vendor for comparison with the blown fuse.

PREVIOUS OCCURRENCES There have been no previous similar occurrences.

NRC FORM 366A (04-2018)

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