05000528/LER-2025-001, Unit 1 Loss of High Pressure Safety Injection Safety Function
| ML25142A400 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 05/22/2025 |
| From: | Spina J Arizona Public Service Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| 102-08955-JLS/TR LER 2025-001-00 | |
| Download: ML25142A400 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| 5282025001R00 - NRC Website | |
text
10 CFR 50.73 A member of the STARS Alliance, LLC Callaway
- Diablo Canyon
- Palo Verde
- Wolf Creek Jennifer L. Spina Vice President Nuclear Regulatory & Oversight Palo Verde Nuclear Generating Station P.O. Box 52034 Phoenix, AZ 85072 Mail Station 7602 Tel: 623.393.4621 102-08955-JLS/TR May 22, 2025 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
Subject:
Palo Verde Nuclear Generating Station (PVNGS) Unit 1 Docket No. STN 50-528 / Renewed License No. NPF-41 Licensee Event Report 2025-001-00 Enclosed, please find the Licensee Event Report (LER) 50-528/2025-001-00 that has been prepared and submitted pursuant to 10 CFR 50.73. This LER reports an event in which Unit 1 had a loss of safety function due to both trains of high pressure safety injection being declared inoperable and subsequent entry into Technical Specification Limiting Condition for Operation 3.0.3.
In accordance with 10 CFR 50.4, copies of this LER are being forwarded to the Nuclear Regulatory Commission (NRC) Regional Office, NRC Region IV, and the Senior Resident Inspector.
No new commitments are being made to the NRC by this letter.
Should you need further information regarding this submittal, please contact Matthew S. Cox, Department Leader, Nuclear Regulatory Affairs, at (623) 393-5753.
Sincerely, JLS/TR/cr Enclosure: Unit 1 Licensee Event Report 2025-001-00 cc:
J. Monninger NRC Region IV Regional Administrator W. T. Orders NRC NRR Project Manager for PVNGS A. Tran NRC Acting Senior Resident Inspector for PVNGS Spina, Jennifer (Z08962)
Digitally signed by Spina, Jennifer (Z08962)
Date: 2025.05.22 13:37:02 -07'00'
ENCLOSURE Unit 1 Licensee Event Report 2025-001-00
NRC FORM 366 (04-02-2024)
U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)
(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/)
APPROVED BY OMB: NO. 3150-0104 EXPIRES: 04/30/2027
- 1. Facility Name 052 050
- 2. Docket Number
- 3. Page 1 OF
- 4. Title
- 5. Event Date Month Day Year
- 6. LER Number Year Sequential Number Revision No.
- 7. Report Date Month Day Year
- 8. Other Facilities Involved Facility Name Facility Name Docket Number Docket Number
- 9. Operating Mode
- 10. Power Level 050 052
Month Day Year Palo Verde Nuclear Generating Station (PVNGS) Unit 1
00528 4
Unit 1 Loss of High Pressure Safety Injection Safety Function 03 28 2025 2025 001 00 05 22 2025 1
100
Matthew S. Cox, Department Leader, Nuclear Regulatory Affairs (623) 393-5753
16. Abstract (Limit to 1326 spaces, i.e., approximately 13 single-spaced typewritten lines)
On March 28, 2025, at 0106 Mountain Standard Time, while the Train B High Pressure Safety Injection (HPSI) was inoperable for planned Unit 1 outage preparation activities, control room staff declared Train A HPSI inoperable because of an unexpected Train A Essential Chilled Water (EC) chiller low compressor oil temperature. This combination of both A and B HPSI trains being declared inoperable resulted in entry into Technical Specification (TS) Limiting Condition for Operation (LCO) 3.0.3 and a loss of the high-pressure injection safety function.
The cause of this event was that control room staff did not recognize that there was an equipment issue that affected the operability of the Train A HPSI before declaring the Train B HPSI inoperable for planned outage SUHSDUDWLRQactivities. Once control room staff became aware of the Train A HPSI inoperability, Train B HPSI was returned to its normal lineup and TS LCO 3.0.3 was exited, precluding a plant shutdown.
No similar events have been reported by PVNGS in the last three years.Page of
- 3. LER NUMBER YEAR SEQUENTIAL NUMBER REV NO.
052 050 6.CAUSE OF THE EVENT:
The direct cause of this event was that control room staff did not recognize that there was an equipment issue that affected the operability of the Train A HPSI before declaring the Train B HPSI inoperable for planned outage activities.
The apparent cause of this event is less than adequate communication.
7.CORRECTIVE ACTIONS:
IMMEDIATE CORRECTIVE ACTION
Once control room staff became aware of the Train A HPSI inoperability, Train B HPSI was returned to its normal lineup.
CORRECTIVE ACTIONS IDENTIFIED DURING EVALUATION:
Development of briefings to reinforce the communication practices outlined in conduct of operations procedures and to familiarize Operations personnel with the causes of this event.
8.PREVIOUS SIMILAR EVENTS:
No similar events have been reported by PVNGS in the last three years due to the same initial cause.
4 4
Palo Verde Nuclear Generating Station (PVNGS) Unit 1 00528 2025 001 00