05000237/LER-2011-001, Regarding Loss of Containment Cooling Service Water System Due to Stop Log Installation
| ML11207A071 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 07/18/2011 |
| From: | Czufin D Exelon Generation Co, Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| SVPLTR # 11-0033 LER 11-001-00 | |
| Download: ML11207A071 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 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)(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 |
| 2372011001R00 - NRC Website | |
text
Exeltono Exelon Generation Company, LLC www.exeloncorp.com Dresden Nuclear Power Station 65oo North Dresden Road Morris, IL 60450-9765 10 CFR 50.73 SVPLTR # 11-0033 July 18, 2011 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Dresden Nuclear Power Station, Unit 2 and Unit 3 Renewed Facility Operating License No. DPR-19 and DPR -25 NRC Docket No. 50-237 and 50-249 Subject: Licensee Event Report 237/2011-001-00, Loss of Containment Cooling Service Water System due to Stop Log Installation Enclosed is Licensee Event Report 237/2011-001-01, Loss of Containment Cooling Service Water System due to Stop Log Installation, which is a final report. This event is being reported in accordance with 10 CFR 50.73(a)(2)(v)(B), "Any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to remove residual heat."
There are no regulatory commitments contained in this submittal.
Should you have any questions concerning this letter, please contact Mr. Dennis Leggett at (815) 416-2800.
Respectfully, David Cz Site Vice President Dresden Nuclear Power Station Enclosure cc:
Regional Administrator - NRC Region III NRC Senior Resident Inspector - Dresden Nuclear Power Station
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013 (10-2010)
, the NRC may digits/characters for each block) not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Dresden Nuclear Power Station, Unit 2 05000237 1 OF 3
- 4. TITLE Loss of Containment Cooling Service Water System due to Stop Log Installation
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR Dresden Unit 3 05000249 NUMBER NO.
FACILITY NAME DOCKET NUMBER 05 17 2011 2011 001 00 07 18 2011 N/A N/A
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
[o 20.2201(b)
[I 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
[I 50.73(a)(2)(vii)
El 20.2201(d)
[I 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
El 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
[I 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A) 0l 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL 5j 20.2203(a)(2)(ii)
[I 50.36(c)(1)(ii)(A)
El 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
[I 20.2203(a)(2)(iii)
El 50.36(c)(2)
[3 50.73(a)(2)(v)(A)
-] 73.71(a)(4) 100 C] 20.2203(a)(2)(iv)
[I 50.46(a)(3)(ii) 0 50.73(a)(2)(v)(B)
El 73.71 (a)(5)
[: 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 The CCSW system was inoperable for less than 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. Even though the plant's TS allow both subsystems to be inoperable for a specified period of time, the condition results in a loss of function for the CCSW system. Therefore this condition is reportable pursuant to 10 CFR 50.73(a)(2)(v)(B), "Any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to remove residual heat."
C.
Cause of Event
A subsequent investigation was performed to determine the cause of this event. The investigation determined that the cause of the event was a failure of the FLS and maintenance planner to use the appropriate technical human performance, maintenance behaviors and standards associated with the work package revision process. In this case, the work instructions were revised without obtaining the appropriate reviews.
Additionally, there was a lack of administrative barriers in place that would prevent both stop logs from being installed concurrently without prior approval. The stop logs have historically been controlled through maintenance work package instructions.
D.
Safety Analysis
The CCSW system provides cooling water to the containment cooling heat exchangers. CCSW provides both pressure and temperature control for the primary containment in the event of anticipated transients or accident conditions. TS 3.7.1 allows both CCSW subsystems to be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. The 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> completion time is acceptable due to the low probability of a design basis accident during this period of time.
The CCSW system was inoperable for less than 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. Since the probability of occurrence of a design basis accident was low in this case, the health and safety of the public was not compromised as a result of this event.
E.
Corrective Actions
The stop logs were immediately removed.
Dresden Maintenance is developing training to reinforce the role of owner and gatekeeper with the work planners.
Dresden Operations is evaluating the implementation of administrative controls for the stop logs.
Dresden Maintenance is developing and performing a dynamic learning activity to observe the behavior of work planners during the work package revision process.
Training Requests are being developed to evaluate the need for maintenance personnel receiving Technical Human Performance training.
F.
Previous Occurrences
A review of DNPS Licensee Event Reports (LERs) for the last three years did not identify any LERs associated with Losses of Safety Function of the CCSW system.