Event Notification Report for August 23, 2024

EN Revision Imported Date: 8/23/2024

EN Revision Text: PART 21 - HPCI RUPTURE DISC NOT WITHIN TECHNICAL REQUIREMENTS

The following information was provided by the licensee via phone and email:

"Tennessee Valley Authority (TVA) completed an engineering evaluation for a Fike Metal Products 16-inch rupture disc, part number 16-CPV-C, which had failed in March 2024 during an event previously reported to the NRC as Event Notification 57036 and Licensee Event Report 260/2024-002-00.

"The evaluation determined that the failure of the rupture disc constituted a failure to comply by a basic component which resulted in a substantial safety hazard.

"The rupture disc was procured as a non-safety related item from Fike Corporation and commercially dedicated by Paragon Energy Solutions. The disc was supplied to TVA in a satisfactory condition meeting all acceptance criteria. During a routine flowrate surveillance test, the high-pressure coolant injection (HPCI) inner rupture disc developed a hole which caused the Unit 2 HPCI turbine to trip. This resulted in [Browns Ferry Unit 2] entering Technical Specification (TS) Limiting Condition for Operation (LCO) 3.5.1 Condition `C', which is a 14-day shutdown LCO. Per HPCI system design criteria, turbine casing protection disc rupture pressure shall be at 175 psig plus 1 or minus 10 psig and the rupture discs shall be sized for a flow capacity of 600,000 pounds per hour at 200 psig, minimum. The failed HPCI inner rupture disc did not experience pressures above 45 psig since being installed; therefore, the HPCI turbine inner rupture disc did not meet its technical requirements.

"On July 23, 2024, the Browns Ferry Nuclear Plant Site Vice President was notified of the requirement to report this event under 10 CFR 21.21. This is a non-emergency notification required by 10 CFR 21.21(d)(3)(i). A written notification in accordance with 10 CFR 21.21(d)(3)(ii) will be provided within 30 days."

The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:

Both Fike Corporation and Paragon Energy Solutions have been informed of the HPCI inner rupture disc not meeting technical requirements. Known potentially affected plants include Browns Ferry Units 1, 2, and 3.

* * * RETRACTION ON 08/22/24 AT 1522 EDT FROM CHASE HENSLEY TO JOSUE RAMIREZ * * *

The following information was provided by the licensee via phone and email:

"The purpose of this notification is to retract a previous event notification, EN 57245, reported on 7/25/24.
"Continued evaluation has concluded that the failure of the disc was not the result of a failure to comply by a basic component, therefore, the NRC non-emergency 10 CFR 21.21 (d) report was not required and the NRC EN 57245 can be retracted.
"The licensee has notified the NRC Resident Inspector."

Notified R2DO (Masters) and Part 21/50.55 Reactors group (Email).

AGREEMENT STATE REPORT - DAMAGED RADIOGRAPHY CAMERA

The following was received from the Pennsylvania Bureau of Radiation Protection (the Department) via email:

"On August 15, 2024, the licensee notified the Department of a disabled device. It is reportable per 10 CFR 34.101(a)(2) and 30.50(b)(2).

"On July 31, 2024, the licensee reported damage to a QSA 880D (serial number D14778, source serial number FC2203), camera containing 38 curies of Ir-192. The licensee was on site performing weld inspections for a client. After the second exposure, the source did not return to the shielded position. The technicians on site called the radiation safety officer (RSO) and established a restricted area around the source. They also notified the client to keep their personnel away from the area. The RSO arrived on site and was able to retrieve the source. The licensee staff determined that the technicians on site did not receive any overexposure. The RSO received 451 mR during the source retrieval. The badges have been sent to Landauer for verification. The equipment was taken out of service for repair."

PA Event Report Identification Number: PA240017

AGREEMENT STATE REPORT - POSSIBLE DAMAGED PORTABLE GAUGE

The following information was provided by the Virginia Department of Health, Office of Radiologic Health (RMP) via email:

"At approximately 1100 EDT on 8/16/2024, RMP was notified of an incident involving a portable nuclear gauge. At approximately 0900, at a deep trench construction site in Fairfax, a CPN International gauge model MC-1, containing 10 mCi Cs-137 and 50 mCi Am-241, was dropped approximately 15 feet when a rope pulley system slipped. The authorized user notified the radiation safety officer (RSO) who arrived on site and then they notified the RMP.

"Per the RSO, the gauge fell onto dirt at the bottom of a trench. The device landed flat onto the base of the gauge. The gauge functions and is operational. The rod handle was retracted and locked at the time, and the source remained retracted in the shielded position. The RSO obtained survey readings of 0.4 mR/h at 1 meter from the gauge. The gauge was placed in its transportation box, secured in the back of a pickup truck, and transported back to the licensee's office for secure storage. A leak test was obtained and analysis indicates there is no leakage. The gauge will be sent for assessment by an authorized dealer.

"RMP will follow up with an investigation."


THIS MATERIAL EVENT CONTAINS A 'Less than Cat 3' LEVEL OF RADIOACTIVE MATERIAL

Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf

CONTROL ROOM VENTILATION INOPERABLE

The following information was provided by the licensee via email and phone:

"At 2001 EDT on 8/20/2024, it was discovered that both trains of the control room ventilation system were simultaneously inoperable. Due to this inoperability, the system was in a condition that could have prevented the fulfillment of a safety function; therefore, this condition is being reported as an eight-hour notification per 10 CFR 50.72(b)(3)(v).

"There is no impact on the health and safety of the public or plant personnel. The NRC resident inspector has been notified.

"One train of control room ventilation was restored to operable status at 2107 EDT on 8/20/2024."

The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:

While performing canister maintenance on train B, it was discovered that the dampener for train A failed to close. Train B was restored at the conclusion of maintenance.


* * * UPDATE ON 08/21/24 AT 1648 EDT FROM LAUREN ANDERSON TO JOSUE RAMIREZ * * *

The following information was provided by the licensee via email and phone:

"This event is also reportable per 10 CFR 50.72(b)(3)(xiii), loss of emergency assessment capability, as the technical support center facility is located inside the control room envelope."

Notified R2DO (Masters)

CONTROL ROOM FILTRATION SYSTEMS INOPERABLE

The following information was provided by the licensee via fax or email:

"At 2010 CDT on 08/20/2024, with Unit 2 in Mode 1 at 100% power, Train B Essential Chiller was unable to maintain the Chilled Water Outlet Temperature in the required band. Train B Essential Chilled Water and the associated cooled components were declared inoperable. Train B Control Room Makeup and Cleanup Filtration System was declared inoperable due to the unavailability of cooling. Train C Control Room Makeup and Cleanup Filtration System was previously inoperable for planned maintenance for reasons other than loss of cooling. This resulted in the inoperability of two of the three 50-percent capacity safety trains required for accident mitigation.

"This event is reportable under 10 CFR 50.72(b)(3)(v)(D) as a condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident.

"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."

The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:

Train C has been placed back in service and is awaiting testing to verify its ability to perform its safety function. Testing is expected to be completed by 1500 CDT on 08/21/2024. Plant is on a 72 hr S/D clock until restoration is verified.

SECONDARY CONTAINMENT BOUNDARY INOPERABLE

The following information was provided by the licensee via fax and phone:

"At 1200 EDT on 8/21/2024, with Millstone unit 3 in mode 1 at 100 percent power, it was discovered that the secondary containment boundary was inoperable while maintenance activities on the system were in progress. Therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(C) and (D).
"There is no impact on the health and safety of the public and plant personnel. The NRC Resident Inspector has been notified.
"Unit 3 continues to operate in mode 1 at 100 percent power with actions in progress to restore the system to operable within the technical specification allowed outage time. There has been no impact to unit 2, which remains at 100 percent power.

"The state of Connecticut and local towns were notified."