05000237/LER-2017-002-01, Regarding Primary Containment Inboard and Outboard Feedwater Isolation Valves Exceed Leakage
| ML18052A487 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 02/15/2018 |
| From: | Karaba P Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 18-0004 LER 2017-002-01 | |
| Download: ML18052A487 (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)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(v), Loss of Safety Function 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)(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)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) |
| 2372017002R01 - NRC Website | |
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~* Exelon Generation SVPL TR # 18-0004 February 15, 2018 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Dresden Nuclear Power Station, Unit 2 Renewed Facility Operating License Nos. DPR-19 NRC Docket No. 50-237 Dresden Nuclear Power Station 6500 North Dresden Road Morris, IL 60450 10 CFR 50.73
Subject:
Licensee Event Report 237/2017-002-01, Unit 2 Primary Containment Inboard.
and Outboard Feedwater Isolation Valves Exceed Leakage Enclosed is Licensee Event Report 237/2017-002-01, "Primary Containment Inboard and Outboard Feedwater Isolation Valves Exceed Leakage." This report describes events which are being reported in accordance with 1 O CFR 50.73(a)(2)(i)(B), "Any operation or condition which was prohibited by the plant's Technical Specifications," in accordance with 1 O CFR 50.73(a)(2)(ii)(A), "Any event or condition that resulted in the condition of the nuclear power plant, including its principal safety barriers, being seriously degraded," and in accordance with 10 CFR 50.73(a)(2)(v)(C), "Any event or condition that could have prevented the fulfillment of the safety function of... systems that are needed to control the release of radioactive material." This is a supplement to Revision O of LEA 237/2017-002.
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, Peter J Karaba Site Vice President Dresden Nuclear Power Station Enclosure Licensee Event Report 237/2017-002-01 cc:
Regional Administrator-NRC Region Ill NRC Senior Resident Inspector - Dresden Nuclear Power Station
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB: NO. 3150-0104 EXPIRES: 03/31/2020 (04-2017)
, the http://www.nrc.Qov/readinQ-rm/doc-collections/nureQs/staff/sr1022/r3/)
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 Primary Containment Inboard and Outboard Feedwater Isolation Valves Exceed Leakage Limits
- 5. EVENT DATE
- 6. LEA NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED YEAR I SEQUENTIAL I REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR NUMBER NO.
MONTH DAY YEAR N/A N/A FACILITY NAME DOCKET NUMBER 11 01 2017 2017 - 002 01 02 15 2018 N/A N/A
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
D 20.2201(b)
D 20.2203(a)(3)(i>
~ 50. 73(a)(2)(ii)(A)
D 50.73(a)(2)(viii)(A)
D 20.2201 (d)
D 20.2203(a)(3)(ii)
D 50.73(a)(2)(ii)(B)
D 50.73(a)(2)(viii)(B) 5 D 20.2203(a)(1>
D 20.2203(a)(4>
D 5o. 13(a)(2)(iii)
D 50.73(a)(2)(ix)(A)
D 20.2203(a)(2)(i)
D 50.36(c)(1 )(i)(A)
D 50.73(a)(2)(iv)(A)
D 50.73(a)(2)(x)
- 10. POWER LEVEL D 20.2203(a)(2)(n>
D 50.36(c)(1 )(ii)(A)
D 50.73(a)(2)(v)(A)
D 13_11(a)(4)
D 20.2203(a)(2)(rn>
D 5o.3e(c)(2)
D 50.73(a)(2)(v)(B)
D 13.11(a)(5)
D 20.2203(a)(2)(iv)
D 5o.4e(a)(3)(n>
~ 50.73(a)(2)(v)(C)
D 13.11(a)(1>
0 D 20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A)
D 50.73(a)(2)(v)(D)
D 13.11(a)(2)(il D 20.2203(a)(2)(vi)
~ 50.73(a)(2)(i)(B)
D 50.73(a)(2)(vii)
D 13_11(a)(2)(ii)
,,~1:r*,,.
}".} '.s;:
D 50.73(a)(2)(i)(C)
D OTHER Specify in Abstract below or in D.
Safety Analysis
The FW Primary Containment Isolation Valves (PCIV) provide containment isolation to control fission product release and provide reactor coolant pressure boundary isolation in the event of a FW line break.
It was conservatively determined that the unit was susceptible to a FW line breach outside of Primary Containment with the FW PCIVs failed. Dresden's Updated Final Safety Analysis Report (UFSAR) describes any FW breach in the Reactor Building as being bounded by the effects of a main steam line breach. The low probability of pipe rupture and location of the potential FW line breach inside the Reactor Building minimize the risk significance of the two PCIVs failures. The impact to the Core Damage Frequency and Large Early Release Frequency has been determined to be non-risk significant.
E.
Corrective Actions
The immediate corrective actions included replacing valve internals and installed larger test taps for improved testing. Corrective actions from previous occurrences are being implemented for all susceptible valves to prevent recurrence of this type of event.
F.
Previous Occurrences
G.
A search was performed to show previous occurrences for this event, with the following results:
LER 249/2000-004-01 dated 2/15/2001 : Dresden Unit 3 - TS Non Compliance due to Primary Containment Inboard and Outboard FW Isolation Valves Exceeding LLRT Allowable Limits LER 249/2000-005-01 dated 3/16/2001: Dresden Unit 3 - TS Non Compliance due to Primary Containment B Inboard and Outboard Main Steam Isolation Valves Exceeding LLRT Allowable Limits Station Issue Report 1135779 dated 11/04/2010: Dresden Unit 3 - D3R21 LLRT failures of two FW check valves. An Equipment Apparent Cause Analysis was performed.
Station Issue Report 1288720 dated 11/10/2011: Dresden Unit 2 - D2R22 LLRT failures of all FW check valves. A Root Cause Analysis was performed.
LER 237/2013-005-00 dated 1/13/2014: Dresden Unit 2 - Primary Containment Inboard and Outboard Feed Water Isolation Valves Exceed Leakage Limits
Component Failure Data
The check valves are tilting disc check valves, Crane model L973. Page _3_ of _3_