05000341/LER-2018-001, Regarding Secondary Containment Pressure Exceeded Technical Specification Due to Reactor Building HVAC System Manipulation

Regarding Secondary Containment Pressure Exceeded Technical Specification Due to Reactor Building HVAC System Manipulation

ML18054A752
Person / Time
Site:	Fermi
Issue date:	02/23/2018
From:	Polson K DTE Electric Company, DTE Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NRC-18-0013 LER 2018-001-00
Download: ML18054A752 (7)

LER-2018-001, Regarding Secondary Containment Pressure Exceeded Technical Specification Due to Reactor Building HVAC System Manipulation

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(v), Loss of Safety Function 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)(iv)(A), System Actuation 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)(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)
3412018001R00 - NRC Website

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Keith J. Poison Senior Vice President and CNO DTE Energy Company 6400 N. Dixie Highway, Newport, MI 48166 Tel: 734.586.6515 Fax: 734.586.4172 Email: keith.polson@dteenergy.com DTE Energy-February 23, 2018 10 CFR 50.73 NRC-18-0013 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:

Licensee Event Report (LER) No. 2018-001 Pursuant to 10 CFR 50.73(a)(2)(v)(C), DTE Electric Company (DTE) is submitting LER No. 2018-001, Secondary Containment Pressure Exceeded Technical Specification Due to Reactor Building HVAC System Manipulation No new commitments are being made in this submittal.

Should you have any questions or require additional information, please contact Mr. Scott A. Maglio, Manager - Nuclear Licensing, at (734) 586-5076.

Sincerely, Keith J. Polson Senior Vice President and CNO Enclosure: LER No. 2018-001, Secondary Containment Pressure Exceeded Technical Specification Due to Reactor Building HVAC System Manipulation cc: NRC Project Manager NRC Resident Office Reactor Projects Chief, Branch 5, Region III

USNRC NRC-18-0013 Page 2 Regional Administrator, Region III Michigan Public Service Commission Regulated Energy Division (kindschl@michigan.gov)

Enclosure to NRC-18-0013 Fermi 2 NRC Docket No. 50-341 Operating License No. NPF-43 Licensee Event Report (LER) No. 2018-001, Secondary Containment Pressure Exceeded Technical Specification Due to Reactor Building HVAC System Manipulation

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3. PAGE Fermi 2 05000 341 1 OF 4

4. TITLE Secondary Containment Pressure Exceeded Technical Specification Due to Reactor Building HVAC System Manipulation

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED SEUNTA RvFACiITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SENUENTIAL REV MONTH DAY YEAR F5A00 NUMBER NO.

05000 FACILITY NAME DOCKET NUMBER 01 11 2018 2018 001 00 02 23 2018 05000

9. OPERATING MODE

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

E 20.2201(b)

[

20.2203(a)(3)(i)

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

Q 50.73(a)(2)(viii)(A) 1 20.2201(d)

Q 20.2203(a)(3)(ii)

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

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

E 20.2203(a)(1)

Q 20.2203(a)(4)

Q 50.73(a)(2)(iii)

[

50.73(a)(2)(ix)(A) 20.2203(a)(2)(i)

E 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)

Q 50.36(c)(1)(ii)(A)

] 50.73(a)(2)(v)(A)

[ 73.71(a)(4)

E 20.2203(a)(2)(iii)

E 50.36(c)(2) 50.73(a)(2)(v)(B)

[

73.71(a)(5) 20.2203(a)(2)(iv)

E 50.46(a)(3)(ii)

/

50.73(a)(2)(v)(C) 73.77(a)(1) 100 E

20.2203(a)(2)(v)

E 50.73(a)(2)(i)(A)

E 50.73(a)(2)(v)(D)

E 73.77(a)(2)(i)

E 20.2203(a)(2)(vi)

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

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

E OTHER Specify in Abstract below orin During this event, a higher indicated SC pressure was recorded for less than one minute. In Chapter 15 of the Updated Final Safety Analysis Report (UFSAR), RBHVAC is assumed lost at the onset of a Loss of Coolant Accident (LOCA) concurrent with a Loss of Offsite Power. As a result, calculations show that the SC would be pressurized until the SGTS restores vacuum. The structural integrity (i.e., leak tightness) of the SC was re-confirmed on January 11 when SC vacuum was restored to greater than 0.125 inches of vacuum water gauge by starting Division 1 SGTS.

If the DBA LOCA for SC concurrent with a Loss of Offsite Power had occurred during the time when the SC pressure TS limit was exceeded, the SC was sufficiently leak tight such that the SGTS would still have established and maintained vacuum greater than the TS required value.

The radiological consequences of the DBA LOCA for SC contained in Chapter 15 of the Fermi 2 UFSAR result in doses that are below 10 CFR 50.67. The SC is assumed to be at a pressure of 0.0 inches of vacuum water gauge at the onset of the LOCA. For this particular event, had the DBA LOCA for SC actually occurred there would be no increase in magnitude of radiological dose because the recorded pressure of 0.116 inches of vacuum water gauge was bounded by the assumed SC pressure of 0.0 inches of vacuum water gauge.

CAUSE OF THE EVENT

The direct cause of the event was due to a degraded bolt and pivot linkage on the West Exhaust Fan Modulating Damper.

The bolt had eroded, causing a loose-fitting connection, which prevented the damper from fully opening and exhausting the excess air from the building. This resulted in increased pressure within the Reactor Building.

CORRECTIVE ACTIONS

Immediate corrective actions included starting SGTS and restoring the RBHVAC system configuration that was in service prior to the troubleshooting.

The degraded bolt and pivot linkages in the West Exhaust Fan Modulating Damper ((CDMP)) were identified and replaced.

PREVIOUS OCCURRENCES

Six events involving loss of SC due to the issues with the RBHVAC system have been reported in the following LERs:

LER 2013-001 involved a loss of SC function due to an RBHVAC system equipment malfunction. The cause of that event was related to improper damper sequencing.

LER 2013-003 involved a loss of SC function due to an RBHVAC system equipment malfunction. The cause of that event was related to a RBHVAC system trip caused by the lack of steam flow through a heating coil due to inadequate draining of the downstream steam trap.

LER 2015-001 involved the loss of SC function due to an RBHVAC system trip caused by a valid actuation of a freeze protection device.

LER 2015-004 involved the loss of SC function due to reverse rotation of the RBHVAC center exhaust fan during post-maintenance testing caused by reversed electrical leads.

LER 2015-005-01 involved the loss of SC function due to set point drift of the RBHVAC supply damper time delay relay resulting in the dampers moving out of sequence.

LER 2016-005 involved the loss of SC function due to the combined effect of high winds during the RBHVAC startup sequence.Page 4

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