05000237/LER-2016-002, Regarding HPCI Inlet Steam Drain Pot Piping Leak Resulting in HPCI Inoperability
| ML16201A235 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 07/15/2016 |
| From: | Karaba P Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 16-0036 LER 16-002-00 | |
| Download: ML16201A235 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v), Loss of Safety Function 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)(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)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) |
| LER closed by | |
| IR 05000237/2016003 (24 October 2016) | |
| 2372016002R00 - NRC Website | |
text
Exelon Generation SVPL TR # 16-0036 July 15, 2016 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 Generating Station 6500 North Dresden Road Morris, IL 60450 www.exeloncorp.com 10 CFR 50.73
Subject:
Licensee Event Report 237/2016-002-00, Unit 2 HPCI Inlet Steam Drain Pot Piping Leak Resulting in HPCI lnoperability Enclosed is Licensee Event Report 237/2016-002-00, "Unit 2 HPCI Inlet Steam Drain Pot Piping Leak Resulting in HPCI lnoperability". This interim report describes events which are being reported in accordance with 1 O CFR 50.73(a)(2)(v)(D), "Any event or condition that could have prevented the fulfillment of the safety function of... systems that are needed to mitigate the consequences of an accident".
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 237/2016-002-00 cc:
Regional Administrator-NRC Region Ill NRC Senior Resident Inspector-Dresden Nuclear Power Station
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 (11-2015)
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, 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 4
- 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 05000 FACILITY NAME DOCKET NUMBER 05 16 2016 2016 - 002
- - 00 07 15 16 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
D 20.2201 (bl D 20.22os(a)(s)(il 0 50.73(a)(2)(ii)(A) 0 50.73(a)(2)(viii)(A) 1 D 20.2201 (dl D 20.22os(a)(s)(iil 0 50.73(a)(2)(ii)(B) 0 50.73(a)(2)(viii)(B)
D 20.22os(a)(1 l D 20.22os(a)(4l D so.1s(a)(2)(iii) 0 50.73(a)(2)(ix)(A)
D 20.22os(a)(2)(i) 0 50.36(c)(1)(i)(A) 0 50.73(a)(2)(iv)(A) 0 50.73(a)(2)(x)
- 10. POWER LEVEL D 20.22os(a)(2)(ii) 0 50.36(c)(1 )(ii)(A) 0 50.73(a)(2)(v)(A)
D 1s.11 (a)(4l D 20.22os(a)(2)(iiil D so.s6(c)(2) 0 S0.73(a)(2)(v)(B)
D 1s.11(a)(s) 0 20.2203(a)(2)(iv)
D so.46(a)(3J(ii) 0 50.73(a)(2)(v)(C)
D 1s.11(a)(1) 100 0 20.2203(a)(2)(v) 0 50.73(a)(2)(i)(A)
[gl 50.73(a)(2)(v)(D)
D 1s.11(a)(2)(i) 0 20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B) 0 50.73(a)(2)(vii)
D 1s.11(a)(2)(ii)
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0 50.73(a)(2)(i)(C)
D OTHER Specify in Abstract below or in performing each of the functions required by the safety analysis. The Isolation Condenser [BL] and Automatic Depressurization System [JE] remained in service and were capable of removing heat from containment while the vessel is at high pressure and lowering vessel pressure to allow for the low pressure systems to inject. Division I of LPCI remained capable of injection along with both divisions of Core Spray [BM].
Additionally, the Torus Cooling function of LPCI remained available as the primary ~
method of heat removal from primary containment. The torus cooling function of LPCI provides the conne.ction to the ultimate heat sink which was available throughout the evolution.
Additional impacts to the safety analysis will be identified during the investigation.
E.
Corrective Actions
The degraded elbow was replaced with stainless steel material. The replacement of the remaining sections of chrome moly piping and fittings identified previously was verified as completed. The replacement of the remaining sections of chrome moly piping and fittings with stainless steel material was scheduled. Ultrasonic inspections were performed to determine the Extent of Condition.
Additional Corrective Actions may be created during the investigation.
F.
Previous Occurrences
In 2012, two through-wall steam leaks were identified on the line upstream of the AOV-2-2301-29 and 3-2301-29 valves with one leak on each unit. Actions were created and completed to perform inspections on all HPCI steam drain elbows in the turbine building that had not previously been replaced with stainless steel material. A sample of elbows in the reactor building was also inspected to verify the assumption that degradation was due to liquid droplet impingement.
In 2011, a through-wall leak occurred on the AOV 2-2301-29 valve. The cause of this event was Liquid Impingement Erosion.
In 2007, a through-wall leak occurred on a 90 degree elbow in HPCI piping located upstream of the AOV 2-2301-29 valve. The cause of this event was Liquid Impingement Erosion. The elbow was replaced with like for like chrome moly material.
In 2007, a through-wall leak occurred in HPCI piping located downstream of 3-2301-55 valves.
The cause of this event was Flow Accelerated Corrosion as a result of carbon steel pipe.
I Additional operating experience will be reviewed during the investigation.
G.
Component Failure Data
Manufacturer Model N/A N/A S/N None YEAR 2016.
Type SEQUENTIAL NUMBER 002 1 inch chrome moly elbow piping Additional information may be determined during the investigation. REV NO.
00