05000237/LER-2015-002, Regarding 2C ERV Failed to Actuate During Extent of Condition Testing
| ML15097A008 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 04/03/2015 |
| From: | Marik S Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| SVPLTR 15-0028 LER 15-002-00 | |
| Download: ML15097A008 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 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 |
| 2372015002R00 - NRC Website | |
text
Exe!Lon Generations, Dresden Nuclear Power Station 6500 North Dresden Road Morris. IL 60450 815 942 2920 Telephone www.exeloncorp.com 10 CFR 50.73 SVPLTR # 15-0028 April 03, 2015 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-1 9 NRC Docket No. 50-237
Subject:
Licensee Event Report 237/2015-002-00, 2C ERV Failed to Actuate during Extent of Condition Testing Enclosed is Licensee Event Report 237/2015-002-00, "2C ERV Failed to Actuate during Extent of Condition Testing." This is an interim report which describes events which are being reported in accordance with 10 CFR 50.73(a)(2)(i)(B), any operation or condition which was prohibited by Technical Specifications.
There are no regulatory commitments contained in this submittal.
Should you have any questions concerning this letter, please contact Mr. Bruce Franzen at (815) 416-2800.
Respectfully, Shane M. Mani Site Vice President Dresden Nuclear Power Station Enclosure: Licensee Event Report 237/2015-002-00 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: 01/31/2017 (02-2014)
Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />.
Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by LICENSEE EVENT REPORT (LER) intemet e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and (See Page 2 for required number of Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC sfor each block) 20503. If a means used to impose an information collection does not display a currently valid OMB digits/characters fcontrol number, the NRC may 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 2C ERV Failed to Actuate during Extent of Condition Testing
- 5. EVENT DATE
- 6. LER NUMBER
[
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONT A
YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR FACILITY NAME DOCKET NUMBER NUMBER NO.
FACILITY NAME DOCKET NUMBER
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
El 20.2201(b)
El 20.2203(a)(3)(i)
[]
50.73(a)(2)(i)(C)
[]
50.73(a)(2)(vii) 4l 20.2201(d)
El 20.2203(a)(3)(ii)
[I 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
E] 20.2203(a)(1)
El 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B) 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL El 20.2203(a)(2)(ii)
El 50.36(c)(1)(ii)(A)
E] 50.73(a)(2)(iv)(A)
E] 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)
El 20.2203(a)(2)(iv)
E] 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71(a)(5) 0E 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)
[
50.73(a)(2)(i)(B)
[]
50.73(a)(2)(v)(D)
Specity in Abstract below or in
_____________NRC___FoNRCmorm36A
- 12. LICENSEE CONTACT FOR THIS LER LICENSEE CONTACT TELEPHONE NUMBER (Include Area Code)
Bruce Franzen - Regulatory Assurance Manager 1815-416-2800CAUSE I
SYSTEM ICOMPONENT I MANU-REPORTABLE II CUE SSMANU-REPORTABLE FACTURER TO EPIX
CAUSE
SYSTEM COMPONENT FACTURER TO EPIX X
SB RV D243 Y
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR SUBMISSION YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
[E NO DATE 05 15 15 ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On February 7, 2015, with the reactor in mode 4, an Electromatic Relief Valve (ERV) actuator failed to open during the performance of an extent of condition testing. The testing involved an operator manually actuating the ERV from the main control room with operators and engineers staged in the field. However, when the demand signal was given, the 2C actuator plunger did not move and the valve did not open.
Initial corrective actions involved replacement of all four ERVs with an upgraded design.
This failure has been preliminarily determined to be of very low safety significance.
This event is being reported under 10 CFR 50.73(a)(2)(i)(B) "Any operation or condition which was prohibited by the plant's Technical Specifications."
rhe cause of the failure is under investigation.
NRC FORM 366 (02-2014)
PLANT AND SYSTEM IDENTIFICATION
Dresden Nuclear Power Station (DNPS), Unit 2, is a General Electric Company Boiling Water Reactor with a licensed maximum power level of 2957 megawatts thermal. The Energy Industry Identification System codes used in the text are identified as [XX].
A.
Plant Conditions Prior to Event:
Unit: 02 Event Date: 02-07-2015 Event Time: 12:29 CST Reactor Mode: 4 Mode Name: Cold Shutdown Power Level: 000 percent B.
Description of Event
On February 7, 2015, with the reactor in mode 4, an Electromatic Relief Valve (ERV) [RV] actuator failed to open during the performance of an extent of condition testing. The testing involved an operator manually actuating the ERV from the main control room with engineers staged in the field.
However, when the demand signal was given, the 2C actuator plunger did not move and the valve did not open.
Initial corrective actions involved replacement of all four Unit 2 ERVs with an upgraded design. This completes the replacement of all ERVs for Dresden Unit 2 and 3.
This failure has been preliminarily determined to be of very low safety significance This event is being reported under 10 CFR 50.73(a)(2)(i)(B) "Any operation or condition which was prohibited by the plant's Technical Specifications."
C.
Cause of Event
Exelon Powerlabs, LLC, has provided an initial report outlining the autopsy performed on the failed actuator. This autopsy is being included in the ongoing root cause investigation.
D.
Safety Analysis
The ERVs are used, in conjunction with Low Pressure Coolant Injection (LPCI) [BO], as a back-up to the High Pressure Coolant Injection (HPCI) [BJ] system during a small area break loss of coolant accident. The ERVs are used with the SRVs and Target Rock for overpressure protection during Anticipated Transient Without Scram (ATWS) scenarios. Based upon the Dresden PSA notebook, success criteria can be met with one valve failing to operate.
As HPCI, the Isolation Condenser (BL], the remaining three ERVs, the Target Rock relief valve, and eight safety relief valves were available; this failure is of very low safety significance.
E.
Corrective Actions
Replacement of the four Unit 2 ERV actuators with an improved design Additional corrective actions will be through a root cause investigation.
F.
Previous Occurrences
Previous Occurrences will be determined by the root cause investigation.
G.
Component Failure Data
Manufacturer Model S/N Type Dresser Industries 1525VX-3-OS108 DA39300 Relief Valve