05000237/LER-2009-003, Emergency Diesel Generator Oil Leak
| ML092170143 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 08/03/2009 |
| From: | Hanley T Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| SVPLTR # 09-0034 LER 09-003-00 | |
| Download: ML092170143 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(v), Loss of Safety Function 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 |
| 2372009003R00 - NRC Website | |
text
Exel in.
Nuclear 10 CFR 50.73 SVPLTR # 09-0034 August 3, 2009 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Dresden Nuclear Power Station, Unit 2 Renewed Facility Operating License No. DPR-19
.NRC Docket No. 50-237
Subject:
Licensee Event Report 237/2009-003-00, "Emergency Diesel Generator Oil Leak" Enclosed is Licensee Event Report 237/2009-003-00, "Emergency Diesel Generator Oil Leak,"
for Dresden Nuclear Power Station, Unit 2. This event is being reported in accordance with 10 CFR 50.73(a)(2)(i)(B) and 10 CFR 50.73(a)(2)(v)(D). There are no regulatory commitments contained in this submittal.
Should you have any questions concerning this report, please contact Ms. Marri Marchionda-Palmer, Regulatory Assurance Manager, at (815) 416-2800.
Respectfully, Tim Hanley Site Vice President Dresden Nuclear Power Station Enclosure cc:
Regional Administrator - NRC Region III NRC Senior Resident Inspector - Dresden Nuclear Power Station
bcc:
Officer of Nuclear Facility Safety - IEMA - DNS Director - Licensing Manager - Licensing - Clinton, Dresden, and Quad Cities Stations Regulatory Assurance Manager - Dresden Nuclear Power Station Midwest Document Control Desk Licensing Plant Manager - Dresden Nuclear Power Station Regulatory Assurance Manager - Dresden Nuclear Power Station LER Coordinator - Dresden Nuclear Power Station INPO Coordinator - Dresden Nuclear Power Station Commitment Tracking Coordinator - Dresden Nuclear Power Station Dresden Regulatory Assurance, SVP File SVP Numerical File - SVPLTR # 09-0034 E-MAIL: LER Completed File electronic in L:\\8360\\8301\\237/180/2009-003
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/2010 19-2007)
, 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 (DNPS), Unit 2 05000237 1 OF 4
- 4. TITLE Emergency Diesel Generator Oil Leak
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED R
FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SENUEBENAL NEV MONTH DAY YEAR DNPS Unit 3 05000249 FACILITY NAME DOCKET NUMBER 06 02 2009 2009 - 003-00 08 03 2009 N/A N/A
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
[1 20.2201(b)
El 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
[I 50.73(a)(2)(vii)
El 20.2201 (d)
El 20.2203(a)(3)(ii)
[] 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A) 0l 20.2203(a)(1)
[I 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
El 20.2203(a)(2)(i)
E3 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii) 0l 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL 0l 20.2203(a)(2)(ii)
[I 50.36(c)(1)(ii)(A)
El 50.73(a)(2)(iv)(A) 0l 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
El 50.36(c)(2)
El 50.73(a)(2)(v)(A)
El 73.71 (a)(4) 100 [E
20.2203(a)(2)(iv)
[I 50.46(a)(3)(ii)
[I 50.73(a)(2)(v)(B)
El 73.71(a)(5)
[I 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
E3 50.73(a)(2)(v)(C)
El OTHER El 20.2203(a)(2)(vi)
[
50.73(a)(2)(i)(B) 0 50.73(a)(2)(v)(D)
Specify in Abstract below or in element, inspecting the element, then reinstalling the element and replacing the cap. There were no remarks in the work package regarding the presence of the plug (plastic or metallic) in the strainer cap. This was a missed opportunity to identify and remove the shipping plug.
On April 16, 2009, the Unit 2/3 EDG was run for post maintenance operability and on May 9, 2009, for the monthly operability surveillance, as required by the plant's TS. No leaks were noted from the strainer housing.
As no conditions were changed on the 2/3 EDG until the work window in April 13-16, 2009, the Unit 2/3 EDG remained capable of meeting the 24-hour surveillance requirement until the time of strainer inspection in the work window. It is believed that once the strainer was reassembled after the inspection, it had an increased probability of failure. Based on this, the Unit 2/3 EDG is considered to have been inoperable from the time it was returned to service on April 16, 2009, until its restoration to service after the strainer plug replacement on June 2, 2009. With the Unit 2/3 EDG inoperable, Units 2 and 3 were required to perform surveillance requirement (SR) 3.8.1.1, ("Verify correct breaker alignment and indicated power availability for each required offsite circuit.") within one hour.
However, this action was not completed and, as a result, TS 3.8.1.F.1 applied, requiring the affected Units to be in Mode 3 within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. This requirement was not met. Therefore, this event is reportable pursuant to 10 CFR 50.73(a)(2)(i)(B).
During the inoperability of the Unit 2/3 EDG, the redundant Units 2 and 3 EDGs were taken out of service for maintenance or testing on the following dates:
Unit 2 EDG taken out of service on April 20, 2009 and May 14, 2009 Unit 3 EDG taken out of service on April 28, 2009, May 26, 2009, and May 27, 2009 The Units 2 and 3 EDG approximate outage times on the above dates ranged between 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and 20 minutes and 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and 49 minutes. With two required EDGs inoperable, Technical Specification (TS) 3.8.1.E requires one of the required EDGs to be restored to operable status within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. As this requirement was not met, TS 3.8.1.F.1 again applied, requiring the affected Units to be in Mode 3 within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. However, in each case the out-of-service redundant EDG was restored to service within the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> period. Therefore, these outages are not reportable pursuant to 10 CFR 50.73(a)(2)(i)(B).
As stated above, the redundant Units 2 and 3 EDGs were unavailable for short periods of time concurrently with the inoperability of the Unit 2/3 EDG. This (minimally) impacted the ability of onsite emergency power to fulfill its safety function. This event is considered reportable per 10 CFR 50.73(a)(2)(v)(D).
(Note: Offsite power remained available during the inoperability of the Unit 2/3 EDG.)
C.
Cause of Event
The root cause of the event was determined to be inadequate purchase order description. As the result of the inadequate description, the vendor did not supply the Quality Level 1 part with a metallic
pressure retaining plug in the "Y" strainer blow off outlet.
Contributing causes were human performance weaknesses concerning receipt and installation of the strainer. As the result of these weaknesses, site personnel did not identify, or question the installation of, the plastic plug.
D.
Safety Analysis
The risk significance of the event was analyzed. The core damage probability (CDP) and Large Early Release probability (LERP) calculations showed, using conservative probabilistic risk assessment (PRA) model assumptions, that the installation of the plastic plug is non-risk significant.
The safety significance of this event is minimal. The "Y" strainer leak was detected in a timely manner and the consequences of the event had minimal impact on the health and safety of the public and reactor safety.
E.
Corrective Actions
Planned corrective actions include the following:
Revise the purchase order description of the "Y" strainer to include a pressure retaining pipe plug of appropriate material.
Provide job performance coaching for the individuals involved with ordering, receiving, and installing the strainer.
F.
Previous Occurrences
A review of the DNPS corrective action program database and the Operating Experience database for the past three years did not identify a similar occurrence at the station.
G.
Component Failure Data
Mueller Steam Specialty Model No. 352M "Y" strainer assembly