05000461/LER-2018-001, Degraded Personnel Airlock Interlock Results in Loss of Primary Containment

Degraded Personnel Airlock Interlock Results in Loss of Primary Containment

ML18151A471
Person / Time
Site:	Clinton
Issue date:	05/29/2018
From:	Stoner T Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
U-604429 LER 2018-001-00
Download: ML18151A471 (4)

LER-2018-001, Degraded Personnel Airlock Interlock Results in Loss of Primary Containment

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)(iii) 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)(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
4612018001R00 - NRC Website

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Clinton Power Station 8401 Power Road Clinton, lL 61727

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~ Exelon Generation U-604429 May 29, 2018 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461

Subject:

Licensee Event Report 2018-001-00 10 CFR 50.73 SRRS 5A.108 Enclosed is Licensee Event Report (LER) 2018-001-00: Degraded Personnel Airlock Interlock Results in Loss of Primary Containment. 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 KP/larn Attachment: License Event Report 2018-001-00 cc:

Regional Administrator - Region Ill NRC 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 0MB: NO. 3150-0104 EXPIRES: 03/31/2020 (02-2018)

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

1. Facility Nan*1e

2. Docket Number 3.Page Clinton Power Station, Unit 1 05000461 1

OF 3

4. Title Degraded Personnel Airlock Interlock Results in Loss of Primary Containment

5. Event Date

6. LEA Number

7. Report Date

8. Other Facilities Involved I

Sequential I Rev Facility Name Docket Number Month Day Year Year Number No.

Month Day Year 05000 Facility Name Docket Number 03 30 2018 2018 -

001 00 05 29 18 05000

9. Operating Mode

11. This Report is Submitted Pursuant to the Requirements of 1 O CFR §: {Check all that apply)

D 20.2201(b)

D 20.2203(a)(3)(il [gJ 50. 73(a)(2)(ii)(A)

D 50.73(a)(2)(viii)(A)

D 20.2201(d)

D 20.2203(a)(3)(ii)

D 50.73(a)(2)(ii)(B)

D 50.73(a)(2)(viii)(B) 1 D 20.2203(a)(1 l D 20.2203(a)(4l D

D 50.73(a)(2)(iii)

50. 73(a)(2)(ix)(A)

D 20.2203(a)(2)(il 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)(iil D 50.36(c)(1)(ii)(A)

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

D 13.11(aH4l D 20.2203(a)(2)(iiil D 50.36(c)(2)

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

D 13.11(a)(5l D 20.2203(a)(2)(iv)

D 5o.46(a)(3)(iil [8J 50.73(a)(2)(v)(G)

D 13.11(a)(1) 098 D 20.2203(a)(2)(v)

D 50.73(a)(2)(i)(A)

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

D 13.11(a)(2)(iil D 20.2203(a)(2)(vi)

D 50.73(a)(2)(i)(B)

D 50.73(a)(2)(vii)

D 13_11(a)(2)(m)

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

D Other (Specify in Abstract below or in D.

Safety Consequences

There was minimal safety consequence associated with this event. The condition of both airlock doors being open simultaneously lasted less than a minute and ended when the interior airlock door was closed. The event was evaluated against the required safety functions for the Primary Containment as described in the Technical Specifications and Updated Safety Analysis Report. Had a design basis accident loss of coolant accident occurred while both doors were open, the safety function of the Primary Containment would have been maintained. Due to release timing assumptions in the dose analysis, the interior door would have been closed prior to any radioactive release. The total dose released would have been within the 1 O CFR 50.67 limits. Other Primary Containment safety functions were not impacted.

This event is reportable under the provisions of 1 O CFR50.73(a)(2(ii)(A) as the condition of the nuclear power plant including its principal safety barriers (Primary Containment), being seriously degraded, and 1 O CFR 50.73(a)(2)(v)(C) as an event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.

This event has been evaluated to not constitute a safety system functional failure based on an engineering evaluation.

E.

Corrective Actions

The interior door was closed immediately which restored Primary Containment operability.

Maintenance personnel conducted an investigation to establish the cause of the event then repaired the containment airlock interlock. Corrective actions include creation of a preventative maintenance task to perform an in-depth inspection of Primary Containment airlocks.

F.

Previous Similar Occurrences No previous events were identified associated with the loss of Primary Containment due to degraded airlock components.

G.

Component Failure Data

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