05000341/LER-2024-002, Primary Containment Isolation Valve Declared Inoperable for a Period Prohibited by Technical Specifications
| ML24137A008 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 05/16/2024 |
| From: | Peter Dietrich DTE Electric Company |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| NRC-24-0035 LER 2024-002-00 | |
| Download: ML24137A008 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3412024002R00 - NRC Website | |
text
Peter Dietrich Senior Vice President and Chief Nuclear Officer DTE Electric Company 6400 N. Dixie Highway, Newport, MI 48166 Tel: 734.586.4153 Fax: 734.586.1431 Email: peter.dietrich@dteenergy.com May 16, 2024 10 CFR 50.73 NRC-24-0035 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 Fermi 2 Power Plant NRC Docket No. 50-341 NRC License No. NPF-43
Subject:
Licensee Event Report (LER) No. 2024-002 Sincerely, Peter Dietrich Senior Vice President and Chief Nuclear Officer Enclosure: Licensee Event Report No. 2024-002, Primary Containment Isolation Valve cc:
NRC Project Manager NRC Resident Office Regional Administrator, Region III DTE
Enclosure to NRC-24-0035 Fermi 2 NRC Docket No. 50-341 Operating License No. NPF-43
Abstract
At 1718 EDT on March 17, 2024, it was identified that E4150-F042, HPCI Booster Pump Suction from Suppression Pool Inboard Iso MOV, was not fully closing without holding down the pushbutton in the Main Control Room. The Primary Containment Isolation function (PCIV) of E4150-F042 was declared inoperable. This condition did not challenge the ability of Primary Containment to perform its overall safety function. On March 19th, actions were taken to replace the associated Closed Auxiliary Seal-in contact block and restore the PCIV function of E4150-F042. A Past Operability evaluation was conducted, which determined that upon a HPCI System steam line isolation signal from the HPCI control logic, E4150-F042 would not fully close. The PCIV function of E4150-F042 was declared inoperable for a period exceeding that which is allowable per TS 3.6.1.3. This condition is being reported under 10CFR50.73(a)(2)(i)(B), operation or condition which is prohibited by plant technical specifications.
There were no safety consequences or radiological releases associated with this event. The cause of the E4150-F042 not fully closing is due to the Closed Auxiliary Seal-in Contact failing to keep the close contactor coil energized due to high resistance across the electrical contacts.
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- 3. LER NUMBER YEAR SEQUENTIAL NUMBER REV NO.
052 050 On 03/19/2024 at 1039, the entire Closed Auxiliary Seal-in contact block was replaced. Following required testing, E4150-F042 was functioning as designed, and the E4150-F042 PCIV safety function was restored to operable status.
SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS
This Licensee Event Report (LER) is being made pursuant to 10CFR50.73(a)(2)(i)(B) as a condition or operation prohibited by technical specifications. There were no safety consequences or radiological releases associated with this event. At no time during this event was there a potential for endangering the public health and safety.
CAUSE OF THE EVENT
The cause for the failure of the Closed Auxiliary Seal-in contact to keep the close contactor coil energized due to high resistance across the electrical contacts was determined to be dirty contacts. The cause of the dirty contacts is unknown.
CORRECTIVE ACTIONS
The entire Closed Auxiliary Seal-In contact block was replaced.
PREVIOUS OCCURRENCES
None 3
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