05000354/LER-2016-001, Regarding High Pressure Coolant Injection System Found to Be Inoperable During Testing
| ML16278A094 | |
| Person / Time | |
|---|---|
| Site: | Hope Creek  |
| Issue date: | 10/04/2016 |
| From: | Casulli E Public Service Enterprise Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LR-N16-0176 LER 16-001-00 | |
| Download: ML16278A094 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 3542016001R00 - NRC Website | |
text
PSEG Nuclear LLC P.0. Box 236, Hancocks Bridge, New Jersey 08038-0236 LR-N16-0176 OCT 0 4 2016 United States Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-001 Hope Creek Generating Station Unit 1 Renewed Facility Operating License No. NPF-57 Docket No. 50-354 11Sf~G Nuclear LLC 10CFR50.73
Subject:
Licensee Event Report 2016-001-00, High Pressure Coolant Injection System Found to be Inoperable During Testing.
In accordance with the requirements of 10 CFR 50.73(a)(2)(v)(D), PSEG Nuclear LLC is submitting the enclosed Licensee Event Report (LER) Number 2016-001-00, High Pressure Coolant Injection System Found to be Inoperable During Testing.
If you have any questions or require additional information, please contact Mr. Thomas MacEwen at (856) 339-1097.
There are no regulatory commitments contained in this letter.
Sincerely, Edward T Casulli Plant Manager Hope Creek Generating Station ttm Attachment: Licensee Event Report 2016-001-00
LR-N16-0176 Page 2 Document Control Desk cc:
Mr. Daniel Dorman, Regional Administrator-Region I, NRC Ms. Carleen Parker, Project Manager-US NRC 10CFR50.73 Mr. Justin Hawkins, NRC Senior Resident Inspector-Hope Creek (X24)
Mr. Patrick Mulligan, Manager IV, NJBNE Mr. Thomas MacEwen, Hope Creek Commitment Tracking Coordinator (H02)
Mr. Lee Marabella - Corporate Commitment Tracking Coordinator (N21)
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 01/31/2017 (02-2014)
- ~J'IJ
- .!\\t-(f~
, the NRC may not conduct or sponsor, and a person is not required to respond to, the Information collection.
- 6. LER NUMBER
- 3. PAGE YEAR I
SEQUENTIAL I REVISION NUMBER NUMBER 3 OF4 2016
- - 001
- - 000 No specific cause was identified. However, there is industry operating experience that the reset spring may relax over time, reducing the preload on the reset mechanism. Relaxation of the reset spring is considered to be the most probable cause.
SAFETY CONSEQUENCES AND IMPLICATIONS
This event resulted in inoperability of the single train HPCI system, resulting in the inability of the HPCI system to perform its required safety function to mitigate the consequences of an accident. The HPCI system is part of the Emergency Core Cooling System (ECCS), and is specifically intended for a small break in the reactor coolant pressure boundary (RCPB) that does not result in rapid depressurization of the reactor vessel. The system was found in a condition in which it remained capable of Injecting water into the reactor vessel, however because of the momentary trip and reset, the system would not have met the full flow injection time limit of 35 seconds.
In the event that the HPCI system fails, the Automatic Depressurization System (ADS) {SB} uses a number of the reactor safety/relief valves to reduce reactor vessel pressure during small or isolated breaks. When reactor vessel pressure is reduced to within the design capability of the low pressure systems (Core Spray {BM} and Low Pressure Coolant Injection {BO} ), these systems provide reactor vessel coolant inventory makeup, so that acceptable post-accident reactor core coolant temperatures are maintained.
During the time period between the last successful HPCI test on March 1, 2016 to until the condition was discovered on April 7, 2016, the following ECCS systems were unavailable for scheduled maintenance:
- The B Low Pressure Coolant Injection (LPCI) system was unavailable due to planned maintenance from March 8, 2016 at 0300 until March 9, 2016 at 2140.
- The B Core Spray subsystem was unavailable due to planned maintenance from March 22, 2016 at 0300 until March 23, 2016 at 2337.
ECCS logic requires at least one Core Spray subsystem or one LPCI pump be operating in order for the ADS to depressurize the reactor vessel and restore core cooling. At no time during the period of HPCI unavailability was the combination of operable low pressure ECCS pumps less than the required number for ADS system operation.
During the time period that the HPCI system was unavailable, sufficient systems were available to provide the required safety functions needed to protect the health and safety of the public.
SAFETY SYSTEM FUNCTIONAL FAILURE This condition is a safety system functional failure as defined in NEI 99-02, Revision 7, Regulatory Assessment Performance Indicator Guideline.
PREVIOUS EVENTS A review of events at Hope Creek for the past three years was performed to determine if any similar events had occurred. No similar events were identified.
CORRECTIVE ACTIONS
APPROVED BY OMB: NO. 3150-0104 EXPIRES: 01/31/2017
, the NRC may not conduct or sponsor, and a person is not required to respond to, the Information collection.
- 6. LER NUMBER
- 3. PAGE YEAR I
SEQUENTIAL I REVISION NUMBER NUMBER 4 OF4 2016
- 001
- 000 The over-speed assembly reset spring was reset to 3.5 lbs., which is within the proper pre-load band.
The preventative maintenance strategy for HPCI will be reviewed and revised as necessary to include periodic replacement of the over-speed assembly reset spring.
Other corrective actions are being tracked in the licensee's Corrective Action Program.
COMMITMENTS
This LER contains no regulatory commitments.