05000333/LER-2023-001, Primary Containment Isolation System Isolation Due to Initiation of Main Condenser Fire Protection Foam System
| ML23109A246 | |
| Person / Time | |
|---|---|
| Site: | FitzPatrick  |
| Issue date: | 04/19/2023 |
| From: | Timothy Peter Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| JAFP-23-0017 LER 2023-001-00 | |
| Download: ML23109A246 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation |
| 3332023001R00 - NRC Website | |
text
Constellation.
JAFP-23-0017 April 19, 2023 United States Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555-0001 James A. FltzPatrlck NPP P.O. Box 110 Lycoming. NY 13093 Timothy C. Peter Site Vice President-JAF James A. FitzPatrick Nuclear Power Plant Renewed Facility Operating License No. DPR-059 NRC Docket No. 50-333
Subject:
Dear Sir or Madam:
LER: 2023-001-00, Primary Containment Isolation System Isolation due to Initiation of Main Condenser Fire Protection Foam System This report is being submitted pursuant to 10 CFR 50.73(a)(2)(iv)(A).
There are no new regulatory commitments contained in this report.
Questions concerning this report may be addressed to Mr. Mark Hawes, Regulatory Assurance Manager (Acting), at (315) 349-6659.
Tim Site Vice President TCP/MH/pa
Enclosure:
LER: 2023-001-00, Primary Containment Isolation System Isolation due to Initiation of Main Condenser Fire Protection Foam System cc:
USNRC, Region I Administrator USNRC, Project Manager USNRC, Resident Inspector INPO Records Center (IRIS)
NRC FORM 366 (08-2020)
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (03-14-2023)
APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/2023
- 1. Facility Name James A. FitzPatrick Nuclear Power Plant 050
- 2. Docket Number 05000333
- 3. Page 1 OF 3 052
- 4. Title Primary Containment Isolation System Isolation due to Initiation of Main Condenser Fire Protection Foam System
- 5. Event Date
- 6. LER Number
- 7. Report Date
- 8. Other Facilities Involved
Month
Day
Year
Year Sequential Number Revision No.
Month Day Year Facility Name N/A 050 Docket Number N/A 02 19 2023 2023 - 001 - 00 04 20 2023 Facility Name N/A 052 Docket Number N/A
- 9. Operating Mode 1
- 10. Power Level 100 Month Day Year No Yes (If yes, complete 15. Expected Submission date)
Abstract (Limit to 1560 spaces, i.e., approximately 15 single-spaced typewritten lines)
At 0105 EST on February 19, 2023, with the James A. FitzPatrick Nuclear Power Plant (JAF) at 100 percent power, a High Main Steam Line Radiation signal initiated a primary containment isolation valve closure signal in multiple systems. During the performance of FPP-3.25 Fire Protection Manifold #5 Sprinkler System Main Drain and Water Flow Alarm Test, the main condenser foam system was inadvertently initiated, resulting in firefighting foam intrusion into a sump which migrated to the main condenser and eventually to the reactor coolant system. The cause was determined to be a human performance related error during testing.
Corrective actions include conducting human performance training and evaluations and hardening of the impacted plant sump system.
(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/)
(See Page 3 for required number of digits/characters for each block)
LICENSEE EVENT REPORT (LER)
=
Background===
James A. FitzPatrick Nuclear Power Plant (JAF) has two firefighting foam systems: the main condenser foam system [EIIS identifier: KQ], which is the subject of this event, and the High Pressure Coolant Injection (HPCI) foam System. The purpose of main condenser foam system is to provide fire extinguishment for the Main Condenser Liquid Holding Pit. The foam system was provided on the basis that the oil from any major turbine oil leak would drain to the pit and a foam system would be effective in fire extinguishment in a confined pit area.
Inside the same building, the turbine building equipment drain sump [WK], also known as the low conductivity sump, is designed to collect, and hold leakage from turbine building equipment drains. During power operation, the low conductivity water in the sump is drawn into the main condenser [SD] with vacuum drag.
This water is combined with main condenser condensate water and returned to the Reactor Coolant System (RCS) [AB]. Two pumps are also available to move water out of the sump to the condenser or radwaste treatment.
Event Description
On February 18, 2023, at 23:00, with the JAF at 100 percent power, a scheduled test began for FPP-3.25, Fire Protection Manifold #5 Sprinkler System Main Drain and Water Flow Alarm Test. The purpose of the test is to demonstrate water supply is available to the sprinkler system supplied from Manifold #5 and to demonstrate operability of the waterflow alarm. The step in the procedure being performed by the control room stated to Press Acknowledge button at Panel FPP and verify Red CONDENSER PIT FOAM SYS light is on, and alarm bell is off; however, the operator depressed the main condenser foam system initiation pushbutton instead of the acknowledge pushbutton, at 00:42 on February 19.
The foam system injected, per design, into the Main Condenser Liquid Holding Pit and a foam/water mixture migrated to the nearby turbine building equipment drain sump. The main condenser vacuum drag drew the foam/water mixture out of the sump into the main condenser hotwell which was then introduced into the RCS via the condensate and feedwater system [JB].
At 01:06, Main Steam Line Hi-Hi radiation actuated Primary Containment Isolation System (PCIS) [JM]
Group 1 isolation signal. Reactor Water Recirculation (RWR) [AD] sample valve 02-2AOV-39 and 02-2AOV-40 closed. The isolation signal also isolated the normally closed Main Steam Line Drain System [SB] and Condenser Air Removal System [SH].
At 01:14, Operators isolated the high conductivity sump vacuum drag flow path and aligned it to radwaste.
This stopped the intrusion of high conductivity foam into the condenser. Conductivity, off-gas radiation, and main steam line radiation then returned to pre-transient values.
This event was reported in accordance with 10 CFR 50.72(b)(3)(iv)(A) via ENS 56373. This report is submitted in accordance 10 CFR 50.73(a)(2)(iv)(A). U.S. NUCLEAR REGULATORY COMMISSION (03-14-2023)
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/2023
- 1. FACILITY NAME 050
- 2. DOCKET NUMBER
- 3. LER NUMBER James A. FitzPatrick Nuclear Power Plant 05000333 YEAR SEQUENTIAL NUMBER REV NO.
052 2023
- - 001
- - 00 Page 3 of 3 (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/)
Event Analysis
The initiation of the main condenser foam system resulted in high conductivity water/foam mixture accumulating in the Main Condenser Liquid Holding Pit flooded the turbine building equipment drain sump.
Through the vacuum drag process, the sump contents were drawn into the main condenser, mixed with condensate water, and then introduced into the reactor coolant.
Fire foam contains organic compounds which breakdown in the presence of radiation in the reactor. One by-product, Oxygen-16, becomes activated by a neutron and decays into the isotope Nitrogen-16. Nitrogen-16 has a very short half-life of 7.13 seconds. When it decays, the radiation was detected by the Main Steam radiation monitors and resulted in the Main Steam Line Hi-Hi radiation signal. The signal is designed to detect potential fuel failures or a postulated Control Rod Drop Accident. However, the increase in Nitrogen-16 was much larger than the background level designed for during normal full power operation. The radiation increase during this event was temporary and returned to normal levels when the turbine building equipment drain sump was isolated from the main condenser.
Cause
The cause of this event was a failure of the Operator to self-check when performing the task resulting in a human performance error and the wrong pushbutton being depressed.
Similar Events
No similar events were identified at JAF.
Corrective Actions
Completed Actions Physical Plant: Sealed the openings on the top of the turbine building equipment drain sump and installed a berm around the sump.
Barrier Control: Placed signage on fire protection panel door requiring permission to open the door.
Performance Management: Qualifications were removed from the operator and remediation along with further evaluation completed.
Planned Actions Perform a human performance evaluation with Reactor Operators and Equipment Operators. Determine training needs based on the results of the evaluation.
Safety Significance
Nuclear safety - There were no actual radiological consequences. The Nitrogen-16, produced as a result of the water/fire foam mix being introduced reactor coolant system, decayed quickly, and has a short half-life of just over 7 seconds. The Offgas System [WF] is designed to hold up isotopes in piping where it has time to decay to very low levels.
References Issue Report - IR 04555544, Inadvertent Initiation of Condenser Foam, dated February 19, 2023