05000334/LER-2021-001, Regarding Containment Isolation Valve Found Restrained Open Resulting in Condition Prohibited by Technical Specifications
| ML21187A275 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 07/06/2021 |
| From: | Grabnar J Energy Harbor Corp |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-21-168 LER 2021-001-00 | |
| Download: ML21187A275 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3342021001R00 - NRC Website | |
text
111f21 energy
harbor John J. Grabnar Site Vice President July 6, 2021 L-21-168 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
SUBJECT:
Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 LER 2021-001-00 10 CFR 50.73 Beaver Valley Power Station P.O. Box 4 Shippingport, PA 15077 724-682-5234 Fax. 724-643-8069 Enclosed is Licensee Event Report (LER) 2021-001-00, "Containment Isolation Valve Found Restrained Open Resulting in Condition Prohibited by Technical Specifications."
This event is being reported in accordance with 10 CFR 50. 73(a)(2)(i)(B).
There are no regulatory commitments contained in this submittal. Any actions described in this document represent intended or planned actions and are described for information only.
If there are any questions or if additional information is required, please contact Mr. Steve Sawtschenko, Manager, Regulatory Compliance and Emergency Response, at 724-682-4284.
Sincerely, John J. Grabnar Enclosure: Beaver Valley Power Station, Unit 1 LER 2021-001-00 cc:
Mr. D. C. Lew, NRC Region I Administrator NRC Senior Resident Inspector Ms. S. Goetz, NRC Project Manager INPO Records Center (via INPO Industry Reporting and Information System)
Mr. L. Winker (BRP/DEP)
Enclosure L-21-168 Beaver Valley Power Station, Unit 1 LER 2021-001-00
Abstract
Beaver Valley Power Station, Unit 1 334 4
Containment Isolation Valve Found Restrained Open Resulting in Condition Prohibited by Technical Specifications 05 08 2021 2021 001 00 07 06 2021 3
0 Steve Sawtschenko, Manager, Regulatory Compliance and Emergency Response 724-682-4284 On May 8, 2021, during startup from the 27th Beaver Valley Power Station, Unit 1 (BVPS-1) refueling outage, BVPS-1 entered Mode 4 and then Mode 3 without satisfying Technical Specification (TS) 3.6.3, Containment Isolation Valves, Limiting Conditions for Operation as required by LCO 3.0.1 and LCO 3.0.4. TS 3.6.3 LCO requires containment isolation valves be operable in Modes 1, 2, 3 and 4. TS LCO 3.0.1 requires that LCOs be met during Modes or other specified conditions in the Applicability. TS LCO 3.0.4 requires that with an LCO not met, entry into a Mode of applicability shall only be made when the associated actions to be entered permit continued operation in the Mode for an unlimited period of time or when a risk assessment has been performed determining that entry into the Mode is acceptable. Contrary to LCO 3.0.4, while in Mode 3, it was discovered that containment isolation check valve 1QS-4 (quench spray pump discharge check valve) was inoperable. The check valve was inadvertently left open during performance of a loop seal fill procedure while in Mode 5.
The root cause was determined to be a loss of configuration control of 1QS-4 due to human performance errors by the Operations supervisor. The corrective action is to revise the loop fill procedure to direct that the check valves are added to the containment penetration log when being restrained open. This event is being reported under 10 CFR 50.73(a)(2)(i)(B) for operation or condition prohibited by TS.Page of 05000-
- 3. LER NUMBER YEAR SEQUENTIAL NUMBER REV NO.
CAUSE OF EVENT (Continued)
Following the attempt to fill the loop seal, Operations requested NDE to evaluate the level in the loop seals with NDE confirming that both train A and B loop seals were satisfactory. Once determined that both loop seals were satisfactory, due to conflicting priorities, the restoration steps that should have been performed in accordance with 1OM-13.4.O were not performed.
On day shift May 3, 2021, the BVPS lead NDE inspector determined that the train B loop seal needed to be refilled, and Operations attempted to refill this loop seal. At this point, the operating crew believed 1QS-4 to be in its NSA position.
Rather than restraining 1QS-4 open, they elected to open MOV-1QS-101B such that the RWST would provide enough static head to open 1QS-4 and fill the loop seal. This was properly documented in the logs. The loop seal was later determined by NDE to be satisfactory. Between the determination that the loops seals were satisfactory on May 2, 2021 and the final disposition of the train B loop seal, the working copy of the procedure which indicated the steps were not yet complete for 1OM-13.4.O was misplaced. At this time, since the working procedure had been misplaced, the Operations supervisor assumed that all steps had been completed and that 1QS-4 was therefore in its NSA position.
ANALYSIS OF EVENT
Since BVPS-1 entered Mode 4 and then Mode 3 with 1QS-4 inoperable, and without meeting the requirements of LCO 3.0.4, this is reportable under 10 CFR 50.73(a)(2)(i)(B) for operation or condition prohibited by TS.
The risk impact of having the quench spray pump discharge check valve 1QS-4 in the open position when it is required to be closed is negligible. The Probabilistic Risk Analysis (PRA) only models 1QS-4 for its function to open and provide quench spray flow following a Containment Isolation Phase B (CIB) signal, and this function was not impacted by the valve being restrained open. The containment isolation function of 1QS-4 is not modeled in the PRA since the valve is required to open and supply quench spray flow into containment in a severe accident. Additionally, the likelihood of an accident generating CIB conditions while the plant remained in Modes 4 and 3 is very small, and if it were to occur the existing recovery procedures include steps to close the outside containment isolation valve (MOV-1QS-101B) for this penetration once quench spray flow is no longer required, to prevent any potential release through this line. Therefore, this event had very low safety significance.
CORRECTIVE ACTIONS
Completed Actions:
Operations removed the restraint and returned 1QS-4 to NSA on May 8, 2021.
Planned Actions:
Revise 1OM-13.4.O to direct that valves 1QS-3/1QS-4 are added to the containment penetration log when being restrained open.
PREVIOUS SIMILAR EVENTS
A review of the previous three years identified that no similar events have occurred at BVPS.
CR-2021-03771 4
4 Beaver Valley Power Station, Unit 1 00334 2021 001 00