05000325/LER-2024-001, Primary Containment Penetration Local Leak Rate Testing Failure
| ML24102A123 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 04/10/2024 |
| From: | Krakuszeski J Duke Energy Progress |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| RA-24-0074 LER 2024-001-00 | |
| Download: ML24102A123 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 3252024001R00 - NRC Website | |
text
U.S. Nuclear Regulatory Commission Page 2 of 2 cc (with enclosure):
Ms. Laura Dudes, NRC Regional Administrator, Region II Mr. Luke Haeg, NRC Project Manager Mr. Gale Smith, NRC Senior Resident Inspector
Abstract
At approximately 08:37 Eastern Standard Time (EST), on February 17, 2024, with Unit 1 in Mode 5 at 0% power during a planned refueling outage, it was determined that the Unit 1 primary containment leakage rate did not meet the 10 CFR 50, Appendix J, requirements, as specified in Technical Specification 5.5.12, due to the as-found Local Leak Rate Testing (LLRT) results of the Reactor Core Isolation Cooling (RCIC) turbine steam supply line penetration (part of the containment boundary).
Both the inboard and outboard primary containment isolation valves in this line would not pressurize during LLRT.
The inboard and outboard RCIC turbine steam supply line primary containment isolation valves were repaired during the refueling outage. Subsequent LLRT of this containment penetration was satisfactory.
There was no impact on the health and safety of the public or plant personnel. This event is being reported in accordance with 10 CFR 50.73(a)(2)(ii)(A) due to a degraded primary containment isolation boundary, and 10 CFR 50.73(a)(2)(v)(C) since this event could have prevented the fulfillment of the safety function of primary containment.
(See Page 2 for required number of digits/characters for each block)
(See NUREG-1022, R.3 for instruction and guidance for completing this form http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1022/r3/)
Corrective Actions
The inboard and outboard RCIC turbine steam supply line primary containment isolation valves were repaired during the refueling outage. Subsequent LLRT of this containment penetration was satisfactory. In addition, the as-left ILRT was satisfactory.
The subject valves are double disc gate valves that are planned to be replaced with a new design. The current plan is to replace these valves prior to startup from the 2028 refueling outage.
Any changes to corrective actions or completion schedules will be made in accordance with the sites corrective action program.
Previous Similar Events
No previous similar events have occurred within the past 20 years in which the inboard and outboard containment isolation valves in the same containment penetration would not pressurize during LLRT.
Commitments
No regulatory commitments are contained in this report.