05000400/LER-2007-005, B Train of Essential Services Chilled Water Was Inoperable for a Period Longer than Allowed by Technical Specifications
| ML080110079 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 01/04/2008 |
| From: | Henderson K Progress Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| HNP-07-177 LER 07-005-00 | |
| Download: ML080110079 (4) | |
| 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 |
| 4002007005R00 - NRC Website | |
text
Progress Energy Serial: HNP-07-177 JAN 0 4 2008 10 CFR 50.73 U.S. Nuclear Regulatory Commission ATTN: NRC Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400/LICENSE NO. NPF-63 LICENSEE EVENT REPORT 2007-005-00 Ladies and Gentlemen:
The enclosed Licensee Event Report 2007-005-00 is submitted in accordance with 10 CFR 50.73. This report describes a condition prohibited by Technical Specifications (TS) in that the 'B' train of Essential Services Chilled Water was inoperable for a period longer than allowed by TS 3.7.13.
This document contains no new Regulatory Commitment. Please refer any questions regarding this submittal to Mr. Dave Corlett, Supervisor -
Licensing/Regulatory Programs, at (919) 362-3137.
Sincerely, Kelvin Henderson Plant General Manager Harris Nuclear Plant KH/adz Enclosure cc:
Mr. P. B. O'Bryan, NRC Sr. Resident Inspector Ms. M. G. Vaaler, NRC Project Manager Mr. V. M. McCree, NRC Regional Administrator Progress Energy Carolinas, Inc.
Harris Nuclear Plant P. 0. Box 165 New Hill, NC 27562 I(I/4
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/2010 (9-2007)
, the NRC may not conduct digits/characters for each block) or sponsor, and a person is not required to respond to, the information digis/carater foreac blck)collection.
- 3. PAGE Harris Nuclear Plant - Unit 1 050004001 1 OF 3
- 4. TITLE
'B' Train of Essential Services Chilled Water was inoperable for a period longer than allowed by Technical Specifications
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE 1
- 8. OTHER FACILITIES INVOLVED NDASEQUENTIAL REV T
FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER NO.
MONTH DAY YEAR 05000 1
4 FACILITY NAME DOCKET NUMBER 11 5
2007 2007 - 005 -
00 1
4 2008 N/A 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply)
[E 20.2201(b)
El 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
El 50.73(a)(2)(vii)
El 20.2201(d)
El 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A)
[1 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
El 20.2203(a)(4)
El 50.73(a)(2)(ii)(B) 0l 50.73(a)(2)(viii)(B)
El 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii)
[I 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL El 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)
E: 20.2203(a)(2)(iii)
El 50.36(c)(2)
[I 50.73(a)(2)(v)(A)
El 73.71(a)(4)
El 20.2203(a)(2)(iv)
[I 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71(a)(5) 100 El 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
[I 50.73(a)(2)(v)(C)
El OTHER El 20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Abstract below or in I1. CAUSE OF EVENT The root cause of this event is that the post-maintenance testing was not adequate to detect leakage of refrigerant to the receiver tank. The tests performed following this infrequent maintenance item were unable to detect the presence of leakage internal to the system from the turbopak to the receiver tank.
A contributing cause of this event was that the task to shut 1 CY-7 was poorly performed by the non-licensed operator. There were no unusual characteristics of the work location that directly contributed to this event.
Another contributing cause was that there is no periodic monitoring of receiver tank level performed that would allow detection of refrigerant transfer leading to loss of chiller function.
Ill.
SAFETY SIGNIFICANCE
The failure of the B ESCW chiller to start and run reliably prevented the 'B' train chiller from providing nominal 44 degree F inlet chilled water to cooling coils in the Air-Handling units associated with plant safety systems.
This condition is reportable under 10 CFR 50.73.a.2.i.B as a condition prohibited by Technical Specifications.
During the period of 10/23/07 through 11/5/07, the 'A' ESCW system was in operation and fully functioning to supply all required loads.
Potential Safety Consequences:
If a Design Basis Accident had occurred between 10/23/07 at 09:55 through 11/5/07 at 19:16, the 'B' ESCW train would not have been capable of performing its safety related functions. The corresponding consequences of having 'B' ESCW incapable of performing safety related functions are minimized by the existence of the 100% capacity redundant 'A' ESCW train. The 'A' ESCW train, which includes the 'A' chiller, was in service and fully functional during this time period.
IV. CORRECTIVE ACTIONS
The most practical means of preventing recurrence of the root cause of this failure is to revise two procedures to require an evacuation test of the receiver tank following refrigerant transfers. Successful completion of this test will ensure that leakage from the turbopak to the receiver will not occur.
There are three corrective actions to address the failure to fully shut 1CY-7. The first corrective action is to coach the individual responsible and all independent verifiers involved on expected performance and work practices. An additional corrective action is specified to revise the Operating Procedure to specify tight closure of 1CY-7 and to provide caution statements informing the operator of the consequences of leakage past 1CY-
- 7. The third corrective action is to brief the entire operations staff regarding the lessons learned from this investigation The corrective action to address the lack of monitoring is to revise the system Trending Basis Document to monitor receiver tank level once per day on Reactor Auxiliary Building (RAB) operator rounds. The RAB operator rounds will also be revised to add the monitoring requirement.
V.
PREVIOUS SIMILAR EVENTS
There are two previous similar events that resulted in ESCW system being inoperable for a period longer than allowed by Technical Specifications. While the events are somewhat similar in nature, the corrective actions taken could not be expected to prevent an event such as the trip on 11/5/2007.