05000305/LER-2008-003, Door Bottom Seal Failure Results in Inoperability of Control Room Ventilation System
| ML090700124 | |
| Person / Time | |
|---|---|
| Site: | Kewaunee  |
| Issue date: | 02/27/2009 |
| From: | Scace S Dominion Energy Kewaunee |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 09-126 LER 08-003-00 | |
| Download: ML090700124 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 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)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3052008003R00 - NRC Website | |
text
Dominion Energy Kewaunee, Inc.
N490 Highway 42, Kewaunee, WI 54216-9511 FEB 27 ZOO$
ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 Serial No.09-126 LIC/RR/RO Docket No.: 50-305 License No.: DPR-43 DOMINION ENERGY KEWAUNEE, INC.
KEWAUNEE POWER STATION LICENSEE EVENT REPORT 2008-003-00 Pursuant to 10 CFR 50.73, Dominion Energy Kewaunee, Inc., hereby submits the following Licensee Event Report applicable to Kewaunee Power Station.
Report No. 50-305/2008-003-00 This report has been reviewed by the Facility Safety Review Committee and will be forwarded to the Management Safety Review Committee for its review.
If you have any further questions, please contact Mr. Richard Repshas at (920) 388-8217.
Very truly yours, Ste ken E. Scace Site Vice President, Kewaunee Power Station Attachment Commitments made by this letter: NONE iZI~z7 0
Serial No.09-126 Page 2 of 2 cc:
Regional Administrator, Region III U.S. Nuclear Regulatory Commission 2443 Warrenville Road Suite 210 Lisle, IL 60532-4352 Mr. P. S. Tam Sr. Project Manager U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 08-H4A 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Kewaunee Power Station
NRC FORM 366 U.S. NUCLEAR REGULATORYCOMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/2010 (9-2007)
, the NRC (See reverse for required number of may not conduct or sponsor, and a person is not required to respond to, the dig its/characters for each block) information collection.
- 3. PAGE Kewaunee Power Station 05000305 1
OF 4
- 4. TITLE Door Bottom Seal Failure Results in Inoperability of Control Room Ventilation System
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED IIFACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR NUMBER NO FACILITY NAME 12 30 2008 2008 003 00 02 27 2009
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) o 20.2201(b) 0 20.2203(a)(3)(i) 0l 50.73(a)(2)(i)(C)
El 50.73(a)(2)(vii)
N 20.2201(d) 0 20.2203(a)(3)(ii) 0l 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
N 20.2203(a)(1)
El 20.2203(a)(4) 0 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B) o 20.2203(a)(2)(i)
C3 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii)
[I 50.73(a)(2)(ix)(A) oE 20.2203(a)(2)(ii)
El 50.36(c)(1 )(ii)(A)
El 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
- 10. POWER LEVEL El 20.2203(a)(2)(iii)
El 50.36(c)(2)
El 50.73(a)(2)(v)(A)
El 73.71(a)(4) o 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii) 0 50.73(a)(2)(v)(B)
E]
73.71(a)(5) 100 El 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
El OTHER El 20.2203(a)(2)(vi)
El 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Abstract below or in NRC Form 366A
- 12. LICENSEE CONTACT FOR THIS LER NAME TELEPHONE NUMBER (include Area Code)
Dale A. Patterson 920-388-8759CAUSE SYSTEM COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE FACTURER TO EPIX FACTURER TO EPIX
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED LI YES (If yes, complete 15. EXPECTED SUBMISSION DATE) Z] NO SUBMISSION MONTH DAY YEAR DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On December 30, 2008 with the plant at full power, a Dominion Energy Kewaunee, Inc. plant operator was transiting through a door that was both a steam exclusion barrier and control room exclusion zone barrier (Door 141) when the seal at the bottom of the door separated from the door. The door was in this condition for forty-four minutes while the bottom seal was replaced. The opening caused by the missing seal exceeded the allowable opening size for the door's steam exclusion and control room exclusion zone barrier functions.
Technical Specification operability requirements for the control room post-accident recirculation system were impacted based on the control room post-accident habitability analysis assumption for air inleakage to the control room envelope and the control room itself from the nonfunctional steam exclusion and control room exclusion zone barrier. The control room post-accident recirculation system and control room exclusion zone were declared inoperable.
This condition is being reported pursuant to 10 CFR 50.73(a)(2)(ii)(B) as a condition that resulted in the nuclear power plant being in an unanalyzed condition. Additionally, since both trains of the control room post-accident recirculation system were inoperable, this condition also meets the reporting criteria of 10 CFR 50.73 (a)(2)(v)(B), any event or condition that could have prevented the fulfillment of a safety function.
NRC FORM 366 (9-2007)
PRINTED ON RECYCLED PAPERU.S. NUCLEAR REGULATORY COMMISSION (9-2007)
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE I
SEQUENTIAL REV YEAR NUMBER NO.
Kewaunee Power Station 05000305 2
OF 4
2008 003 00
Event Description
On December 30, 2008 at 1113 CDT with the plant at full power, a Dominion Energy Kewaunee, Inc. (DEK) plant operator was transiting into the control room air conditioning room through a door that was both a steam exclusion (SE) barrier and control room exclusion zone barrier (CREZ) (Door 141) [DR] when the seal [SEAL] separated from the bottom of the door. With the seal separated from the door, the resultant opening exceeded the allowable opening size for the door's SE and CREZ functions. The door was immediately closed and a watch posted at the door to prevent nonessential personnel from entering the room. The bottom seal was promptly replaced, thus returning functionality of the door. The door was in the degraded condition for forty-four minutes.
Door 141 is a SE barrier and CREZ barrier that supports both trains of control room post-accident recirculation system (CRPAR) [AHU] and the control room itself. Normal ingress and egress is allowed; however, hazard barrier doors are not allowed to have openings exceeding certain requirements. With the seal removed, the door was considered non-functional. Per the guidance of NRC RIS 2001-09, "Control of Hazard Barriers," a component "...that is credited with mitigating a HELB (high energy line break) event would be rendered inoperable if a barrier that is credited with protecting the (component) from the effects of the postulated HELB event is removed." Consequently, during the period the bottom seal was not in place, the control room post-accident recirculation system and CREZ were inoperable.
Kewaunee Power Station Technical Requirements Manual (TRM) ALCO 3.0.9, "Steam Exclusion System,"
specifies that "all required steam exclusion boundaries such as walls, hatches, etc., shall be OPERABLE."
TRM 3.0.9 Required Action A.1 directs that for an inoperable steam exclusion boundary, "declare all equipment supported by the inoperable steam exclusion barrier inoperable."
In accordance with TRM 3.0.9, all equipment supported by that steam exclusion door was inoperable. The supported zone included the control room air conditioning room and the control room. Thus, both trains of control room post-accident recirculation system and CREZ boundary were inoperable.
TS 3.0.c, "Standard Shutdown Sequence," was entered, and then exited forty-four minutes following completion of repairs. This directs within one hour to place the unit in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, at least HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and at COLD SHUTDOWN within the subsequent 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The door was in this condition for forty-four minutes. The plant remained at full power throughout the event.
Since the control room post-accident recirculation system and the CREZ boundary were inoperable, this condition is being reported pursuant to 10 CFR 50.73(a)(2)(ii)(B) as a condition that resulted in the nuclear power plant being in an unanalyzed condition. Additionally, since the control room post-accident recirculation system was inoperable, this condition also meets the reporting criteria of 10 CFR 50.73(a)(2)(v)(B), any event or condition that could have prevented the fulfillment of a safety function. This condition was initially reported to the NRC via the Emergency Notification System (ENS) on December 30, 2008 (EN 44746).
Event and Safety Consequence Analysis:
The steam exclusion system aids in the mitigation of a high energy line break outside of containment. The primary functions of steam exclusion are to provide suitable environmental conditions for needed equipment operation, and a habitable environment for personnel in areas outside of containment which may require access should a high energy line break occur.
If a steam exclusion boundary is inoperable, a barrier that may be credited with protecting a supportedPRINTED ON RECYCLED PAPERU.S. NUCLEAR REGULATORY COMMISSION (9-2007)
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE SEQUENTIAL REV IYEAR NUMBER NO.
Kewaunee Power Station 05000305 3
OF 4
2008 003 00 component or system is no longer capable of providing that protection. This condition requires that all equipment supported by the inoperable steam exclusion barrier be immediately declared inoperable unless an evaluation has been performed to determine that required equipment supported by the inoperable steam exclusion barrier is OPERABLE.
Since the opening caused by the removed bottom seal on Door 141 was approximately 18 square inches and the SE and CREZ allowed opening were 5.7 and 3.0 square inches respectively, the door was judged to have been non-functional. Since the control room post-accident recirculation system and CREZ boundary were declared inoperable during the period that the door was degraded, this condition constitutes a safety system functional failure.
The CREZ function of Door 141 is to protect the operators from post-accident radiation. That function is not important to core damage risk because the dose likely would not be enough to prevent the operators from performing post-accident functions within the 24-hour mission time assumed in probabilistic risk assessment.
Furthermore, the probability of an accident releasing radiation during the forty-four minute time the door was degraded is very low.
The steam exclusion function of Door 141 is to protect equipment in the control room heating and air conditioning equipment room from excess heat and humidity during a steam line break. The amount of piping in the area of the door consists of a portion of steam header 'A' that passes through the records storage room and a portion of the steam supply to the turbine driven auxiliary feedwater pump [P] that passes near stairwell F. The probability of a break in this limited amount of piping during the forty-four minute time that the door was degraded is very low.
Therefore, the safety significance of this event is very low.
Cause
The cause of this condition was identified as loose and stripped screws that attach the bottom seal to Door 141. This resulted from the design of fastening the seal to the door due to the cyclic loads on the seal frame during operation of the door.
Corrective Actions
As immediate corrective action, the SE barrier and CREZ barrier provided by Door 141 was restored to functional status by replacing the bottom seal on the door. Repairs to the door were completed in forty-four minutes.
Checks of important doors and the instructions for inspections have been incorporated into operator rounds.
A corrective action was initiated to present a project plan to improve design of vulnerable doors to the Plant Health Working Group.
A corrective action was initiated to perform a Maintenance Rule Evaluation of this condition.PRINTED ON RECYCLED PAPERPRINTED ON RECYCLED PAPERU.S. NUCLEAR REGULATORY COMMISSION (9-2007)
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE SEQUENTIAL I
REV YEAR NUMBER INO.
Kewaunee Power Station 05000305 Y
4 OF 4
2008 003 00_1
Similar Events
A review of Licensee Event Reports covering the past three years identified a recent event with a steam exclusion boundary door as a result of partially dislodged weather stripping. It is discussed in LER 2008-002-00.PRINTED ON RECYCLED PAPERPRINTED ON RECYCLED PAPER