05000461/LER-1917-002, Regarding Failure of the Division 1 Diesel Generator Ventilation Fan Load Sequence Relay Circuit During Concurrent Maintenance of RHR Division 2 Results in an Unanalyzed Condition

Regarding Failure of the Division 1 Diesel Generator Ventilation Fan Load Sequence Relay Circuit During Concurrent Maintenance of RHR Division 2 Results in an Unanalyzed Condition

ML17128A410
Person / Time
Site:	Clinton  (NPF-062)
Issue date:	05/04/2017
From:	Stoner T Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
U-604346 LER 17-002-00
Download: ML17128A410 (4)

LER-1917-002, Regarding Failure of the Division 1 Diesel Generator Ventilation Fan Load Sequence Relay Circuit During Concurrent Maintenance of RHR Division 2 Results in an Unanalyzed Condition

Event date:
Report date:
Reporting criterion:	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)(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)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability
4611917002R00 - NRC Website

text

Exelon Generation.

Clinton Power Station 8401 Power Road Clinton, IL 61727 U-604346 May 4, 2017 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001

Subject:

Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRG Docket No. 50-461 Licensee Event Report 2017-002-00 10CFR50.73 SRRS 5A.108 Enclosed is Licensee Event Report (LER) 2017-002-00: Failure of the Division 1 Diesel Generator Ventilation Fan Load Sequence Relay Circuit During Concurrent Maintenance of RHR Division 2 Results in an Unanalyzed Condition. This report is being submitted in accordance with the requirements of 10 CFR 50.73.

There are no regulatory commitments contained in this report.

Should you have any questions concerning this report, please contact Mr. Dale Shelton, Regulatory Assurance Manager, at (217) 937-2800.

Respectfully,

_;:,~~

Theodore R. Stoner Site Vice President Clinton Power Station DRA/cac Attachment: Licensee Event Report 2017-002-00 cc:

Regional Administrator-NRG Region Ill NRG Senior Resident Inspector - Clinton Power Station Office of Nuclear Facility Safety -

Illinois Emergency Management Agency

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104

• EXPIRES: 03/31/2020 (04*2017)

, the htt1;1://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r3/)

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

3. PAGE Clinton Power Station, Unit 1 05000461 1 OF 3

4. TITLE Failure of the Division 1 Diesel Generator Ventilation Fan Load Sequence Relay Circuit During Concurrent Maintenance of RHR Division 2 Results in an Unanalyzed Condition

5. EVENT DATE

6. LER NUMBER

7. REPORT DATE

8. OTHER FACILITIES INVOLVED YEAR I SEQUENTIAL I REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR NUMBER NO.

MONTH DAY YEAR 05000 FACILITY NAME DOCKET NUMBER 03 09 2017 2017 - 002 00 05 04 2017 05000

9. OPERATING MODE

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

D 20.2201 (bl D 20.2203(a)(3J(il D 50. 73(a)(2)(ii)(A)

D 50.73(a)(2)(viii)(A) 1 D 20.2201 (dl D 20.2203(a)(3J(iil

~* 50.73(a)(2)(ii)(B)

D 50.73(a)(2)(viii)(B)

D 20.2203(a)(1)

D 20.2203(a)(4l D 50.13(a)(2J(iiil D 50.73(a)(2)(ix)(A)

D 20.2203(a)(2)(i)

D 50.36(c)(1 )(i)(A)

D 50.73(a)(2)(iv)(A)

D 50.73(a)(2)(x)

10. POWER LEVEL D 20.2203(a)(2)(ii)

D 50.36(c)(1 )(ii)(A)

D 50.73(a)(2)(v)(A)

D 13.11 (a)(4l

• D 20.2203(a)(2J(iii)

D 50.36(c)(2)

D 50.73(a)(2)(v)(B)

D 73.71 (a)(5)

D 20.2203(a)(2)(iv)

D 50.46(a)(3)(ii)

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

D 73.77(a)(1) 099 D 20.2203(a)(2)(v)

D 50.7~(a)(2)(i)(A)

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

D 13.11(a)(2J(il D 20.2203(a)(2)(vi)

~ 50.73(a)(2)(i)(B)

D 50.73(a)(2)(vii)

D 13.11(a)(2)(iil

~

D 50.13(a)(2)(i)(C)

D OTHER Specify in Abstract below or in C.

CAUSE OF EVENT

The root cause of this event is currently under investigation. The causal factors that created this condition and the associated corrective actions will be provided in the next revision to this Licensee Event Report (LER).

D.

SAFETY ANALYSIS

The event is reportable in accordance with 1 O CFR 50.73(a)(2)(i)(B) as a condition which was prohibited by the plant's Technical Specifications.

This event is reportable in accordance with 1 O CFR 50.73(a)(2)(ii)(B) as a condition that resulted in the plant being in an unanalyzed condition that significantly degraded plant safety.

There were no safety consequences associated with the event described in this report since offsite power remained available during the event and no other events occurred necessitating ECCS actuation.

E.

CORRECTIVE ACTIONS

Immediate corrective actions included installation and testing of replacement relays which function as expected, and restoring the EDG ventilation fan and the EOG to an operable status.

Additional corrective actions for this event will be provided in the follow-up LER.

F.

PREVIOUS SIMILAR OCCURENCES

No previous occurrences involving similar circuits and relay interactions have been identified.

G.

COMPONENT FAILURE DATA

No CPS component failures associated with this event have been identified. Page _3_ of _3_