ML25052A166

MD 8.3 Evaluation for Hope Creek - D EDG Water in Lube Oil

ML25052A166
Person / Time
Site:	Hope Creek
Issue date:	02/21/2025
From:	Nicole Warnek, Blake Welling Division of Operating Reactors
To:
References
ML25122A007 IR 05000354/2025050
Download: ML25052A166 (1)

Text

Issue Date: 12/14/23 E1-1 0309 Decision Documentation for Reactive Inspection (Deterministic and Risk Criteria Analyzed)

PLANT: Hope Creek EVENT DATE:

February 19, 2025 EVALUATION DATE:

February 20, 2025 Brief Description of the Significant Operational Event or Degraded Condition:

On February 19, 2025, during a D Emergency Diesel Generator (EDG) preventative maintenance outage, following completion of a maintenance run, lube oil samples were taken with visible water present. Specifically, samples taken at the crankcase and rocker arm lube oil tank sample points were milky in appearance, indicating water in the sample. A sample taken at the lube oil heat exchanger (shell/oil side) sample point showed predominately water initially and then lube oil with a milky appearance, indicating water in the sample.

The licensee sent oil samples to an offsite vendor and is awaiting results to determine the amount of water intrusion and validate the water source. However, initial sample results analyzed at the site on February 20 showed > 13,000 ppm water in the samples from the D EDG crankcase and lube oil heat exchanger, which is above the 1000 ppm limit fault limit for the lube oil. Additionally, initial visual indication, specifically a lack of pink color of the water in the samples, indicated that it was from the Safety Auxiliaries Cooling System (SACS) vice the D EDG jacket water system, which has a corrosion inhibitor added that produces a pinkish hue to the water.

At 1542 on February 20, 2025, Hope Creek declared the D EDG inoperable due to the water levels present in the lube oil. (Note: the EDG was already inoperable for the maintenance window, which began on February 19, 2025.) The licensees troubleshooting is focused on the EDG lube oil heat exchanger, which is the only SACS / lube oil interface. Subsequent testing results by the licensee confirmed SACS as the source of the water in the lube oil system.

A similar water intrusion event occurred previously, on January 31, 2025. Specifically, at 0735 on January 31, an alarm was received on the D EDG for high lube oil filter differential pressure (dP), resulting in the licensee declaring the EDG inoperable. The licensee had taken a crankcase oil sample 8 days prior, on January 23. Results obtained from the vendor on January 31 indicated high water content that was identified as SACS. Subsequent investigation by the licensee was unable to identify a definitive cause; however, eddy current testing on the lube oil heat exchanger identified minor indications on 5 tubes, which were then plugged. Follow on testing did not show further indications of leakage into the D EDG lube oil system. Following restoration activities, a post-maintenance run, and surveillance testing, the D EDG was declared operable at approximately 1700 on February 9, 2025.

The February 19, 2025, water intrusion into the D EDG lube oil constitutes a repetitive failure of the D EDG. The exact cause of water intrusion into the lube oil is unknown; however, the degraded condition may have existed for an extended period of time, starting prior to the initial water sample taken on January 23, 2025, and extending through the recent discovery of water on February 19, 2025.

Issue Date: 12/14/23 E1-2 0309 Y/N DETERMINISTIC CRITERIA N

a. Involved operations that exceeded, or were not included in, the design bases of the facility Remarks: No design bases were exceeded during these events.

N

b. Involved a major deficiency in design, construction, or operation having potential generic safety implications Remarks: There was no identified design, construction or operation having potential generic safety implications.

N

c. Led to a significant loss of integrity of the fuel, primary coolant pressure boundary, or primary containment boundary of a nuclear reactor Remarks: There was no impact or challenge on the integrity of the fuel or primary containment boundary.

N

d. Led to the loss of a safety function or multiple failures in systems used to mitigate an actual event Remarks: These events did not lead to loss of a safety function or cause failures in multiple systems used to mitigate an actual event.

N

e. Involved possible adverse generic implications Remarks: There are no adverse generic implications.

N

f. Involved significant unexpected system interactions Remarks: There were no significant unexpected system interactions.

Y

g. Involved repetitive failures or events involving safety-related equipment or deficiencies in operations Remarks: The safety-related D EDG experienced repetitive failures due to water intrusion into the lube oil system within a one-month period. On January 31, 2025, the D EDG was declared inoperable due to high lube oil differential pressure caused by a SACS leak into the lube oil system. Following repair and restoration to operable status on February 9, 2025, the D EDG was again declared inoperable on February 20, 2025, due to a water leak into the lube oil, also from SACS. Based on the information available at this time, both failures would likely have prevented the D EDG from achieving its safety-related function during an event.

N

h. Involved questions or concerns pertaining to licensee operational performance Remarks: There are no questions or concerns pertaining to licensee operational performance.

Issue Date: 12/14/23 E1-3 0309 CONDITIONAL RISK ASSESSMENT RISK ANALYSIS BY: C. Bickett/F. Arner DATE: 02/20/2025 The SRAs used the Hope Creek SPAR model (Version 8.81) and SAPHIRE (Version 8.2.12) to assess this condition, with the following assumptions and adjustments:

Assumptions Given current information, the SRAs assumed the accumulation of water in the lube oil only occurred while the EDG was running. Therefore, the SRAs modeled failure of the D EDG as a failure to run.

More inspection is required to determine the exposure time of the degraded condition for the D EDG. Because of this uncertainty, for this analysis, the SRAs assumed the exposure time started on 01/23/2025, which was the date of the original D EDG crankcase oil sample that was out of specification due to high water content. The exposure time(s) associated with any potential performance deficiencies evaluated as part of the significance determination process could be longer.

The SRAs considered that the D EDG was inoperable for the entire duration of the A EDG maintenance window (i.e., 01/27/2025 00:00 - 01/31/2025 20:21)

The SRAs considered the 10K107 air compressor unavailable (out of service due to high vibration since 12/24/2024).

The SRAs assumed an end date of 02/20/2025, but risk continues to accrue as PSEG troubleshoots and repairs this condition at power.

SPAR Model Adjustments Set the D EDG fail-to-run basic event to TRUE to model the degraded condition For the period where the A EDG was out of service for a maintenance window, set the A EDG test and maintenance basic event to TRUE.

Set the 10K107 air compressor test and maintenance basic event to TRUE.

Added modeling for the AOT diesel generator and removed the gas turbine generator from the model Added credit for operator action to crosstie of instrument air to the primary containment instrument gas system Added credit for operator action to crosstie of the safety auxiliaries cooling system Updated loss of offsite power initiating event frequencies to 2021 data (INL/RPT 68809)

Adjusted common cause failure to account for the D EDG failure to run with the A EDG in a test and maintenance condition Risk Assessment The SRAs did not have an estimate for fire risk with only the D EDG out of service.

However, during the Notice of Enforcement Discretion call on January 31, 2025, PSEG stated that for 28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br />, with both the A and D EDGs out of service, fire risk would be 2.8E-7/yr. Assuming the D EDG was inoperable for the entire duration of the A EDG maintenance window, the SRAs estimated the fire risk for this condition to be approximately

~9.2E-7/yr.

Using the fire information above, and the Hope Creek SPAR model to quantify internal event risk, the SRAs determined that the total estimated incremental conditional core damage

Issue Date: 12/14/23 E1-4 0309 probability (ICCDP or CDP) was at least ~ 3E-6. There is uncertainty in this result, as it does not include fire risk for periods when just the D EDG was out of service, and overall risk could be higher depending on the cause of the degraded condition and how long the condition existed. Additionally, the SRAs assumed an end date of 02/20/2025, but risk continues to accrue as PSEG troubleshoots and repairs this condition at power. Therefore, based on the assumptions described above, the SRAs concluded that this event falls at least within the no additional inspection/special inspection overlap region (1E-6 to 5E-6).

RESPONSE DECISION USING THE ABOVE INFORMATION AND OTHER KEY ELEMENTS OF CONSIDERATION AS APPROPRIATE, DOCUMENT THE RESPONSE DECISION TO THE EVENT OR CONDITION, AND THE BASIS FOR THAT DECISION DECISION AND DETAILS OF THE BASIS FOR THE DECISION:

The Division of Operating Reactor Safety (DORS), Projects Branch 3, and the regional SRAs, recommend performing a Special Inspection at Hope Creek.

Based on the repetitive failures involving safety-related equipment, specifically the D EDG failures on January 31 and February 20, 2025, one of the IMC 0309 Deterministic Screening Criteria for Risk Assessment are met. Conditional Risk Assessment has been completed showing an estimated incremental conditional core damage probability (ICCDP or CDP) of at least ~ 3E-6 which falls at least within the no additional inspection/special inspection overlap region (1E-6 to 5E-6).

Uncertainty currently exists with respect to the duration of the degraded condition. A special inspection will allow for an independent and timely assessment of the most recent D EDG failure, including an in-depth understanding of licensees troubleshooting efforts and other performance aspects associated with this event. It will also allow the region to ascertain whether Hope Creek implemented adequate troubleshooting efforts and corrective actions associated with the previous failure of the D EDG.

BRANCH CHIEF REVIEW:

DIVISION DIRECTOR REVIEW:

ADAMS ACCESSION NUMBER: ML25052A166 EVENT NOTIFICATION REPORT NUMBER (as applicable): N/A E-mail to NRR_Reactive_Inspection@nrc.gov NICOLE WARNEK Digitally signed by NICOLE WARNEK Date: 2025.02.21 14:10:07 -05'00' BLAKE WELLING Digitally signed by BLAKE WELLING Date: 2025.02.21 14:15:47 -05'00'

Issue Date: 12/14/23 E2-1 0309 Decision Documentation for Reactive Inspection (Deterministic-only Criteria Analyzed)

PLANT: Hope Creek EVENT DATE:

February 19, 2025 EVALUATION DATE:

February 20, 2025 Brief Description of the Significant Operational Event or Degraded Condition:

Refer to Enclosure 1.

REACTOR SAFETY Y/N IIT Deterministic Criteria N

Led to a Site Area Emergency Remarks: The event did not lead to a site area emergency.

N Exceeded a safety limit of the licensee's technical specifications Remarks: No Technical Specification safety limits were exceeded.

N Involved circumstances sufficiently complex, unique, or not well enough understood, or involved safeguards concerns, or involved characteristics the investigation of which would best serve the needs and interests of the Commission Remarks: The event did not involve circumstances sufficiently complex, unique, or not well enough understood, or involved safeguards concerns, or involved characteristics the investigation of which would best serve the needs and interests of the Commission.

Y/N SI Deterministic Criteria N

Significant failure to implement the emergency preparedness program during an actual event, including the failure to classify, notify, or augment onsite personnel Remarks: There was no declared event.

N Involved significant deficiencies in operational performance which resulted in degrading, challenging, or disabling a safety function or resulted in placing the plant in an unanalyzed condition for which available risk assessment methods do not provide an adequate or reasonable estimate of risk.

Remarks: The events did not involve an unanalyzed condition or disabling of a safety system function.

Issue Date: 12/14/23 E2-2 0309 RADIATION SAFETY Y/N IIT Deterministic Criteria N

Led to a significant radiological release (levels of radiation or concentrations of radioactive material in excess of 10 times any applicable limit in the license or 10 times the concentrations specified in 10 CFR Part 20, Appendix B, Table 2, when averaged over a year) of byproduct, source, or special nuclear material to unrestricted areas Remarks: This event did not involve a radiological release N

Led to a significant occupational exposure or significant exposure to a member of the public. In both cases, significant is defined as five times the applicable regulatory limit (except for shallow-dose equivalent to the skin or extremities from discrete radioactive particles)

Remarks: This event did not involve an occupational exposure or exposure to a member of the public.

N Involved the deliberate misuse of byproduct, source, or special nuclear material from its intended or authorized use, which resulted in the exposure of a significant number of individuals Remarks: This event did not involve the misuse of byproduct, source, or SNM.

N Involved byproduct, source, or special nuclear material, which may have resulted in a fatality Remarks: This event did not involve the misuse of byproduct, source, or SNM.

N Involved circumstances sufficiently complex, unique, or not well enough understood, or involved safeguards concerns, or involved characteristics the investigation of which would best serve the needs and interests of the Commission Remarks: This event did not involve circumstances sufficiently complex, unique, or not well enough understood, or involved safeguards concerns, or involve characteristics the investigation of which would best serve the needs and interests of the Commission.

Y/N AIT Deterministic Criteria N

Led to a radiological release of byproduct, source, or special nuclear material to unrestricted areas that resulted in occupational exposure or exposure to a member of the public in excess of the applicable regulatory limit (except for shallow-dose equivalent to the skin or extremities from discrete radioactive particles)

Remarks: This event did not involve a radiological release.

N Involved the deliberate misuse of byproduct, source, or special nuclear material from its intended or authorized use and had the potential to cause an exposure of greater than 5 rem to an individual or 500 mrem to an embryo or fetus

Issue Date: 12/14/23 E2-3 0309 Remarks: This event did not involve the misuse of byproduct, source, or SNM.

N Involved the failure of radioactive material packaging that resulted in external radiation levels exceeding 10 rads/hr or contamination of the packaging exceeding 1000 times the applicable limits specified in 10 CFR 71.87 Remarks: This event did not involve the failure or RAM packaging.

N Involved the failure of the dam for mill tailings with substantial release of tailings material and solution off site Remarks: This event did not involve the failure of the dam for mill tailings.

Y/N SI Deterministic Criteria N

May have led to an exposure in excess of the applicable regulatory limits, other than via the radiological release of byproduct, source, or special nuclear material to the unrestricted area; specifically:

occupational exposure in excess of the regulatory limits in 10 CFR 20.1201 exposure to an embryo/fetus in excess of the regulatory limits in 10 CFR 20.1208 exposure to a member of the public in excess of the regulatory limits in 10 CFR 20.1301 Remarks: This event would not have led to an exposure in excess of regulatory limits.

N May have led to an unplanned occupational exposure in excess of 40 percent of the applicable regulatory limit (excluding shallow-dose equivalent to the skin or extremities from discrete radioactive particles)

Remarks: This event would not have led to an unplanned occupational exposure.

N Led to unplanned changes in restricted area dose rates in excess of 20 rem per hour in an area where personnel were present or which is accessible to personnel Remarks: This event did not involve unplanned changes in dose rates.

N Led to unplanned changes in restricted area airborne radioactivity levels in excess of 500 DAC in an area where personnel were present or which is accessible to personnel and where the airborne radioactivity level was not promptly recognized and/or appropriate actions were not taken in a timely manner Remarks: This event did not involve unplanned changes in restricted area airborne radioactivity levels.

N Led to an uncontrolled, unplanned, or abnormal release of radioactive material to the unrestricted area:

for which the extent of the offsite contamination is unknown; or, that may have resulted in a dose to a member of the public from loss of radioactive material control in excess of 25 mrem (10 CFR 20.1301(e)); or,

Issue Date: 12/14/23 E2-4 0309 that may have resulted in an exposure to a member of the public from effluents in excess of the ALARA guidelines contained in Appendix I to 10 CFR Part 50 Remarks: This event did not involve a release of RAM.

N Led to a large (typically greater than 100,000 gallons), unplanned release of radioactive liquid inside the restricted area that has the potential for ground-water, or offsite, contamination Remarks: This event did not involve a release of radioactive liquid.

N Involved the failure of radioactive material packaging that resulted in external radiation levels exceeding 5 times the accessible area dose rate limits specified in 10 CFR Part 71, or 50 times the contamination limits specified in 49 CFR Part 173 Remarks: This event did not involve the failure of RAM packaging.

N Involved an emergency or non-emergency event or situation, related to the health and safety of the public or on-site personnel or protection of the environment, for which a 10 CFR 50.72 report has been submitted that is expected to cause significant, heightened public or government concern Remarks: This event did not involve an emergency or non-emergency event or situation, related to the health and safety of the public or on-site personnel or protection of the environment, for which a 10 CFR 50.72 report has been submitted that is expected to cause significant, heightened public or government concern.

SAFEGUARDS/SECURITY Y/N IIT Deterministic Criteria N

Involved circumstances sufficiently complex, unique, or not well enough understood, or involved safeguards concerns, or involved characteristics the investigation of which would best serve the needs and interests of the Commission Remarks: This event did not involve circumstances sufficiently complex, unique, or not well enough understood, or involved safeguards concerns, or involved characteristics the investigation of which would best serve the needs and interests of the Commission N

Failure of licensee significant safety equipment or adverse impact on licensee operations as a result of a safeguards initiated event (e.g., tampering).

Remarks: This event did not involve a failure of licensee significant safety equipment or adverse impact on licensee operations as a result of a safeguards initiated event.

N Actual intrusion into the protected area.

Remarks: This event did not involve actual intrusion into the PA.

Y/N AIT Deterministic Criteria Involved a significant infraction or repeated instances of safeguards infractions that

Issue Date: 12/14/23 E2-5 0309 N

demonstrate the ineffectiveness of facility security provisions Remarks: This event did not involve a significant infraction or repeated instances of safeguards infractions that demonstrate the ineffectiveness of facility security N

Involved repeated instances of inadequate nuclear material control and accounting provisions to protect against theft or diversions of nuclear material Remarks: This event did not involve repeated instances of inadequate nuclear material control and accounting provisions to protect against theft or diversions of nuclear material N

Confirmed tampering event involving significant safety or security equipment Remarks: This event did not involve confirmed tampering involving significant safety or security equipment N

Substantial failure in the licensees intrusion detection or package/personnel search procedures which results in a significant vulnerability or compromise of plant safety or security Remarks: This event did not involve substantial failure in the licensees intrusion detection or package/personnel search procedures which results in a significant vulnerability or compromise of plant safety or security Y/N SI Deterministic Criteria N

Involved inadequate nuclear material control and accounting provisions to protect against theft or diversion, as evidenced by inability to locate an item containing special nuclear material (such as an irradiated rod, rod piece, pellet, or instrument)

Remarks: This event did not involve inadequate nuclear material control and accounting provisions to protect against theft or diversion, as evidenced by inability to locate an item containing special nuclear material (such as an irradiated rod, rod piece, pellet, or instrument N

Involved a significant safeguards infraction that demonstrates the ineffectiveness of facility security provisions Remarks: This event did not involve a significant safeguards infraction that demonstrates the ineffectiveness of facility security provisions N

Confirmation of lost or stolen weapon Remarks: This event did not involve a lost or stolen weapon N

Unauthorized, actual non-accidental discharge of a weapon within the protected area Remarks: This event did not involve an unauthorized, actual non-accidental discharge of a weapon within the protected area N

Substantial failure of the intrusion detection system (not weather related)

Remarks: This event did not involve a failure of the intrusion detection system

Issue Date: 12/14/23 E2-6 0309 N

Failure to the licensees package/personnel search procedures which results in contraband or an unauthorized individual being introduced into the protected area Remarks: This event did not involve the licensees package/personnel search procedures resulting in contraband or an unauthorized individual being introduced into the protected area N

Potential tampering or vandalism event involving significant safety or security equipment where questions remain regarding licensee performance/response or a need exists to independently assess the licensees conclusion that tampering or vandalism was not a factor in the condition(s) identified Remarks: This event did not involve potential tampering or vandalism

Issue Date: 12/14/23 E2-7 0309 RESPONSE DECISION USING THE ABOVE INFORMATION AND OTHER KEY ELEMENTS OF CONSIDERATION AS APPROPRIATE, DOCUMENT THE RESPONSE DECISION TO THE EVENT OR CONDITION, AND THE BASIS FOR THAT DECISION DECISION AND DETAILS OF THE BASIS FOR THE DECISION:

None of the deterministic criteria were met for Enclosure 2.

A special inspection is recommended in accordance with the results documented in. Specifically, one deterministic criterion was met (g. Involved repetitive failures or events involving safety-related equipment or deficiencies in operations), and the total estimated incremental conditional core damage probability (ICCDP or CDP) for the event falls within the no additional inspection/special inspection overlap region (1E-6 to 5E-6).

Uncertainty currently exists with respect to the duration of the degraded condition. A special inspection will allow for an independent and timely assessment of the most recent D EDG failure, including an in-depth understanding of licensees troubleshooting efforts and other performance aspects associated with this event. It will also allow the region to ascertain whether Hope Creek implemented adequate troubleshooting efforts and corrective actions associated with the previous failure of the D EDG.

BRANCH CHIEF REVIEW:

DIVISION DIRECTOR REVIEW:

ADAMS ACCESSION NUMBER: ML25052A166 EVENT NOTIFICATION REPORT NUMBER (as applicable): N/A E-mail to NRR_Reactive_Inspection@nrc.gov NICOLE WARNEK Digitally signed by NICOLE WARNEK Date: 2025.02.21 14:10:41 -05'00' BLAKE WELLING Digitally signed by BLAKE WELLING Date: 2025.02.21 14:16:24 -05'00'