05000410/LER-2016-001, Regarding Secondary Containment Inoperable Due to Simultaneous Opening of Airlock Doors
| ML16172A020 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 06/06/2016 |
| From: | Kreider R Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NMP2L 2624 LER 16-001-00 | |
| Download: ML16172A020 (7) | |
| 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)(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) |
| 4102016001R00 - NRC Website | |
text
~, Exelon Gen,eration NMP2L 2624 June 6, 2016 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Nine Mile Point Nuclear Station, Unit 2 Renewed Facility Operating License No. NPF-69 Docket No. 50-41 O 10 CFR 50.73
Subject:
NMP2 Licensee Event Report 2016-001, Secondary Containment Inoperable Due to Simultaneous Opening of Airlock Doors In accordance with the reporting requirements contained in 1 O CFR 50.73(a)(2)(v)(C), please find enclosed NMP2 Licensee Event Report (LER) 2016-001, Secondary Containment Inoperable Due to Simultaneous Opening of Airlock Doors.
There are no regulatory commitments contained in this letter.
Should you have any questions regarding the information in this submittal, please contact Dennis Moore, Site Regulatory Assurance Manager, at (315) 349-5219.
Respectfully, r;:24q7,e~
i Robert E. Kreider Jr.
Plant Manager, Nine Mile Point Nuclear Station Exelon Generation Company, LLC REK/KJK
Enclosure:
NMP2 Licensee Event Report 2016-001, Secondary Containment Inoperable Due to Simultaneous Opening of Airlock Doors cc:
NRG Regional Administrator, Region I NRG Resident Inspector NRG Project Manager
Enclosure NMP2 Licensee Event Report 2016-001, Secondary Containment Inoperable Due to Simultaneous Opening of Airlock Doors Nine Mile Point Nuclear Station, Unit 2 Renewed Facility Operating License No. NPF-69
- __ J NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104
- EXPIRES: 10/31/2018 (11-2015)
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, the NRG may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Nine Mile Point Unit 2 05000410 1 OF 5
- 4. TITLE Secondary Containment Inoperable Due to Simultaneous Opening of Airlock Doors
- 5. EVENT DATE
- 6. LEA 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 N/A N/A FACILITY NAME DOCKET NUMBER 04 07 2016 2016 - 001
- - 00 06 06 2016 N/A N/A
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITIED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: {Check all that apply)
D 20.2201 (bl D 20.2203(a)(3)(i)
D 50.73(a)(2)(ii)(A)
D 50.73(a)(2)(viii)(A)
D 20.2201 (ct)
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 i D 20.2203(a)(4)
D so.13(a)(2)(iii)
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)(4)
D 20.2203(a)(2)(m)
D so.3s(c)(2)
D 50.73(a)(2)(v)(B)
D 13.11 (a)(s)
D 20.2203(a)(2)(iv)
D so.4s(a)(3)(ii)
D 50.73(a)(2)(v)(C)
D 13.11(a)(1) 100 D 20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A)
~ 50.73(a)(2)(v)(D)
D 13.11(a)(2)(i)
D 20.2203(a)(2)(vi)
D 50.73(a)(2)(i)(B)
D 50.73(a)(2)(vii)
D 13.11(a)(2)(ii)
D 50.73(a)(2)(i)(C)
D OTHER Specify in Abstract below or in D. DATES AND APPROXIMATE TIMES OF MAJOR OCCURRENCES AND OPERATOR ACTIONS:
The dates, times, and major occurrences and operator actions for this event are as follows. All.dates are 2016.
April 7 1730 Doors SA262-2 and SA262-3 are opened concurrently.
1730 Personnel recognize that secondary containment has been breached and immediately closed door SA262-2.
1730 Entered TS action statement 3.6.4.1, Condition C and exited.
NMP2 entered TS action statement 3.6.4.1, Condition C, then exited it when door SA262-2 was shut.
E. METHOD OF DISCOVERY
This event was discovered by station personnel traversing the Reactor Building airlock doors.
F. SAFETY SYSTEM RESPONSES:
The duration of each event was 4 to 5 seconds, or less. There was no impact on building differential pressure. Operators entered the applicable TS action statement then exited it soon afterwards. The event concluded when the inner airlock door was shut.
II. CAUSE OF EVENT
This event was caused by the simultaneous opening of Airlock Doors SA262-2 and SA262-3 by workers as they passed through the doors. During the event, both the operator and the supplemental workforce personnel were attempting to utilize the airlock doors in accordance with the posted Notice. However, the requirement to wait 5 seconds to allow personnel who may be traversing to exit, does not reduce the chances of an event when personnel are attempting to enter the airlock from outside opposing airlock doors (not actually traversing).
III. ANALYSIS OF THE EVENT
The reportable condition associated with airlock doors SA262-2 and SA262-3 being open simultaneously represents a potential loss of secondary containment safety function. This condition is reportable under 10 CFR 50.72(b)(3)(v)(C) and 10 CFR 50.73(a)(2)(v)(C). It is defined under paragraph 1 O CFR 50. 73(a)(2)(v)(C) as any event or condition that could YEAR 2016 -
- 3. LEA NUMBER SEQUENTIAL NUMBER 001 have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.
The incident occurred when individuals were attempting to utilize the Unit 2 outer South Auxiliary Bay airlock (doors SA262-2 and SA262-3) on elevation 261 from opposite directions.. An Operator was entering the airlock from RP access into the Reactor Building through door SA262-3. The Operator carded in, opened the door, and started to step into the airlock. Concurrently, two supplemental workforce personnel were exiting the Reactor Building to RP Access through door SA262-2. The breach of secondary containment was immediately realized and the supplemental workforce personnel immediately closed door SA262-2 without entering airlock. During the event, both the operator and the supplemental workforce personnel were attempting to utilize the airlock doors in accordance with the posted Notice. However, the requirement to wait 5 seconds to allow personnel who may be traversing to exit, does not reduce the chances of an event when personnel are attempting to enter the airlock from outside opposing airlock doors (not actually traversing).
In response to the event, the station entered the action statement for TS 3.6.4.1 then promptly exited it when the airlock doors were shut. Computer data identified that secondary containment differential pressure was unaffected by this event Secondary containment structural integrity, the ability to automatically isolate the non-safety related Reactor Building ventilation system, and the GTS availability were not impacted.
Based on the above discussion, it is concluded that the safety significance of this event is low and the event did not pose a threat to the health and safety of the public or plant personnel.
This event does not affect the NRC Regulatory Oversight Process Indicators.
N. CORRECTNEACTIONS:
A. ACTION TAKEN TO RETURN AFFECTED SYSTEMS TO PRE-EVENT NORMAL STATUS:
Airlock door SA262-2 was closed and the secondary containment was restored to Operable status.
B. ACTION TAKEN OR PLANNED TO PREVENT RECURRENCE:
Revise Notice signage at all airlock doors to increase wait time from 5 seconds to 1 O seconds to allow personnel traversing the airlock to exit.
Revise Notice at the three South Auxiliary Bay airlocks to restrict use as follows: "Use airlock R261-1 I R261-2 whenever possible. Use of this airlock should be limited to accessing work location(s) only when necessary."
V. ADDITIONAL INFORMATION
A. FAILED COMPONENTS:
There were no failed components that contributed to this event.
B. PREVIOUS LERs ON SIMILAR EVENTS:
NMP2 LER 2014-007, Revision 1 C. THE ENERGY INDUSTRY IDENTIFICATION SYSTEM (EIIS) COMPONENT FUNCTION IDENTIFIER AND SYSTEM NAME OF EACH COMPONENT OR SYSTEM REFERRED TO IN THIS LER:
COMPONENT Reactor Building (BWR)
Reactor BuildingVentilation System Standby Gas Treatment System Airlock Door D. SPECIAL COMMENTS:
None IEEE 803 FUNCTION IDENTIFIER N/A PDIC N/A DR IEEE 805 SYSTEM IDENTIFICATION NG VA BH NG 00