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Event Notification Report for May 03, 2021

U.S. Nuclear Regulatory Commission
Operations Center

EVENT REPORTS FOR
05/02/2021 - 05/03/2021

Agreement State
Event Number: 55208
Rep Org: CALIFORNIA RADIATION CONTROL PRGM
Licensee: The Regents of the University of California, UC Davis
Region: 4
City: Sacramento   State: CA
County:
License #: 1334-57
Agreement: Y
Docket:
NRC Notified By: Robert Greger
HQ OPS Officer: Brian P. Smith
Notification Date: 04/22/2021
Notification Time: 20:45 [ET]
Event Date: 03/11/2020
Event Time: 00:00 [PDT]
Last Update Date: 04/22/2021
Emergency Class: Non Emergency
10 CFR Section:
Agreement State
Person (Organization):
RAY AZUA (R4DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
Event Text
EN Revision Imported Date: 5/3/2021

EN Revision Text: AGREEMENT STATE - PATIENT UNDERDOSE

The following report was received via e-mail from the California Department of Public Health - Radiation Health Branch [CDPH-RHB]:

"On March 13, 2020, the licensee radiation safety officer (RSO) contacted CDPH-RHB to report a medical event which occurred on March 11, 2020, and was discovered on March 13, 2020. The licensee reported that a patient was prescribed 200 mCi of I-131 NaI for the treatment of thyroid cancer, but received only 60 mCi on the day of therapy (March 11, 2020). The 200 mCi dose was divided into two capsules and the patient was unintentionally only provided one of the two capsules in a medicine cup by the authorized user. The second capsule was reportedly stuck in the shipping vial which the authorized user thought he had emptied. The 140 mCi I-131 capsule was returned to the radiopharmacy in the shipping vial and pig. This error was discovered when the radiopharmacy contacted the licensee on March 13, 2020 to inform them of the capsule's presence in the returned vial. The Medical Director of Nuclear Medicine was immediately notified, who in turn, notified the RSO. The referring physician was also notified on March 13, 2020 and took responsibility for notifying the patient. A subsequent dosage was administered to complete the therapeutic treatment.

"This medical event was initially reported to CDPH-RHB by telephone on March 13, 2020 and by written report dated March 27, 2020. However, CDPH-RHB does not believe that the medical event was reported to the NRC at that time. A recent inspection by CDPH-RHB brought this medical event to their current attention."

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.


Agreement State
Event Number: 55209
Rep Org: GEORGIA RADIOACTIVE MATERIAL PGM
Licensee: NOVA Engineering and Environmental LLC
Region: 1
City:   State: GA
County:
License #: GA 1323-1
Agreement: Y
Docket:
NRC Notified By: IRENE BENNETT
HQ OPS Officer: Rodney Clagg
Notification Date: 04/23/2021
Notification Time: 08:38 [ET]
Event Date: 04/21/2021
Event Time: 00:00 [EDT]
Last Update Date: 04/23/2021
Emergency Class: Non Emergency
10 CFR Section:
Agreement State
Person (Organization):
FRANK ARNER (R1DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
ILTAB (EMAIL)
Event Text
EN Revision Imported Date: 5/4/2021

EN Revision Text: AGREEMENT STATE REPORT - STOLEN RADIOLOGICAL DEVICE

The following was received via email from the State of Georgia.

"[The licensee] called and reported a gauge stolen off the back of one of their work trucks on April 22, 2021. The technician responsible for the gauge was working on the Augusta Airport project. The gauge was left locked and chained in the back of his truck in the motel parking lot overnight. The technician last saw the gauge at 1900 EDT on April 21, 2021. When [the technician] went to the truck [on April 22, 2021] the chain and lock had been cut and the gauge removed. The local Sheriff has been informed and the case number is 21-112409. This has been assigned and more information is forthcoming.

Troxler Model Number: 3400
Serial Number: 22667
Activity: Cs-137 (10mCi); Am-241/Be (40 mCi)

Georgia Radioactive Materials Program NMED Report Incident # 40


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


Agreement State
Event Number: 55210
Rep Org: FLORIDA BUREAU OF RADIATION CONTROL
Licensee: Advent Health
Region: 2
City: Altamonte Springs   State: FL
County:
License #: 2897-1
Agreement: Y
Docket:
NRC Notified By: Matt Senison
HQ OPS Officer: Thomas Kendzia
Notification Date: 04/23/2021
Notification Time: 14:34 [ET]
Event Date: 03/26/2021
Event Time: 00:00 [EDT]
Last Update Date: 04/23/2021
Emergency Class: Non Emergency
10 CFR Section:
Agreement State
Person (Organization):
ARNER, FRANK (R1DO)
NMSS_EVENTS_NOTIFICATION, (EMAIL)
ILTAB, (EMAIL)
Event Text
EN Revision Imported Date: 5/3/2021

EN Revision Text: AGREEMENT STATE REPORT - LOST RADIOLOGICAL DEVICE
The following was received by email from the state of Florida:

"On March 26, 2021, a Co-57 reference vial was left by NMT (Advent Health) with ammo cases in the hotlab for pickup by Jubiliant pharmacy. On March 29, 2021, NMT noted the vial was gone, and later inquired of Jubiliant for transfer paperwork. Jubiliant denied picking up the source. Advent Health has conducted a thorough investigation and search for source and has contacted Jubiliant several more times and have not found the source. Source calibration certificate 07-21-2017, 5.51 mCi [Mfg - Benchmark, Model BM06E, serial # BM06057E17200109]. Jubiliant manager [was contacted]. Advent Health will send in a written report."

Florida Incident Number: FL21-048

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


Hospital
Event Number: 55211
Rep Org: Saint Louis University Hospital
Licensee: Saint Louis University Hospital
Region: 3
City: Saint Louis   State: MO
County:
License #: 24-00196-07
Agreement: N
Docket:
NRC Notified By: Mark Haenchen
HQ OPS Officer: Thomas Kendzia
Notification Date: 04/23/2021
Notification Time: 19:33 [ET]
Event Date: 04/23/2021
Event Time: 12:20 [CDT]
Last Update Date: 04/23/2021
Emergency Class: Non Emergency
10 CFR Section:
35.3045(a)(1) - Dose <> Prescribed Dosage
Person (Organization):
PETERSON, HIRONORI (R3DO)
NMSS_EVENTS_NOTIFICATION, (EMAIL)
O'DOWD (R3)
Event Text
EN Revision Imported Date: 5/3/2021

EN Revision Text: UNDER DOSE DELIVERED DURING MEDICAL TREATMENT

The Radiation Safety Officer for the Saint Louis University Hospital called in and emailed the following notification:

"At approximately 1220 CDT on April 23, 2021, Y-90 SIR-Sphere was being administered to a patient. The prescribed dose [for the liver] was 43.2 mCi, the measured dose to be administered was 46.7 mCi, but due to a clog in the catheter, only a calculated 4.53 mCi dose was administered to the patient. Because this exceeds +/- 20 percent of the intended dose, we determined a medical event had occurred. There was no harm to the patient, and a follow-up dose is planned for Monday, April 26, 2021.

"Preliminary Determination of Cause: The cause of the medical event was believed to be clogging of the catheter, but the exact reason for the resistance was undetermined. When the resistance was encountered, the procedure was stopped by the administering physician, with the intention of terminating the procedure, resulting in an administered dose variance greater than +/- 20 percent of the prescribed dose, and thus determined to be a medical event.

"Additional Details:
 The Nuclear Medicine Technologist drew the dose per standard operating procedure. The procedure checklist was read and the dose administration set up was normal. All steps to prevent clumping of microspheres were followed.
 During the administration, the dose was agitated and attempted to be delivered. There was resistance on the plunger during the administration. The physician stated that the catheter was clogged. The procedure was stopped, with the intention to terminate the procedure, and to administer a second dose at a later time.
 The physician disconnected the A-line from the patient catheter. This caused the backpressure to expel the beads onto the administration table and the floor covering. The disposable covering of these surfaces were collected and disposed of in radioactive waste. The Interventional Radiology Suite was surveyed and released, with all wipe tests and G-M survey meter readings at background."

Licensee notified R3 NRC Inspector (O'DOWD)

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.


Agreement State
Event Number: 55214
Rep Org: WA OFFICE OF RADIATION PROTECTION
Licensee: Virginia Mason Franciscan Health
Region: 4
City: Seattle   State: WA
County:
License #: WN-M048-1
Agreement: Y
Docket:
NRC Notified By: Tristan Hay
HQ OPS Officer: Kerby Scales
Notification Date: 04/26/2021
Notification Time: 15:15 [ET]
Event Date: 04/16/2021
Event Time: 00:00 [PDT]
Last Update Date: 04/26/2021
Emergency Class: Non Emergency
10 CFR Section:
Agreement State
Person (Organization):
PROULX, DAVID (R4DO)
NMSS_EVENTS_NOTIFICATION, (EMAIL)
Event Text
EN Revision Imported Date: 5/4/2021

EN Revision Text: AGREEMENT STATE REPORT - PATIENT UNDERDOSE

The following is a summary of an email received the State of Washington:

The licensee reported a medical event involving an underdose administration of Y-90 Theraspheres on April 16, 2021. The event resulted in an underdose to the liver. Two vials of Y-90 were to be delivered to two different locations in the liver, however surveys after injection of both vials revealed not all activity in vials made it into the patient. The planned activity for each dose was 0.79 GBq. Post treatment measurement of percent dose delivered for dose `A' and dose `B' was 60 percent and 76 percent, respectively. Gamma camera imagining confirmed no Y-90 Theraspheres in the dose-vial. However, imaging visualized activity retained in the delivery tubing. Routine post-imaging demonstrated microsphere distribution in liver segments 4A and 4B. The activity delivered was 0.465 GBq and 0.594 GBq, respectively.

Washington State Incident Number WA-21-008.

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.


Part 21
Event Number: 55223
Rep Org: Paragon Energy Solutions
Licensee: Paragon Energy Solutions
Region: 4
City: Fort Worth   State: TX
County:
License #:
Agreement: N
Docket:
NRC Notified By: Tracy Bolt
HQ OPS Officer: Joanna Bridge
Notification Date: 04/29/2021
Notification Time: 19:52 [ET]
Event Date: 03/29/2021
Event Time: 00:00 [CDT]
Last Update Date: 05/03/2021
Emergency Class: Non Emergency
10 CFR Section:
21.21(d)(3)(i) - Defects And Noncompliance
Person (Organization):
SCHROEDER, DAN (R1DO)
MILLER, MARK (R2DO)
RIEMER, KENNETH (R3DO)
PROULX, DAVID (R4DO)
NMSS_EVENTS_NOTIFICATION, (EMAIL)
Event Text
EN Revision Imported Date: 5/4/2021

EN Revision Text: PART 21 - FAILURE OF SIZE 1 AND 2 FREEDOM SERIES FULL VOLTAGE REVERSING STARTERS

The following is a summary of information received from Paragon Energy Solutions:

On 3/29/2021, Dominion - North Anna Station has identified instances where size 1 and 2 starters have failed to function as expected in assemblies that were originally supplied by Nuclear Logistics LLC (NLI). The mechanical interlock exhibited binding that prevented the contactor from closing when energized. The identified failed starters are utilized in an application of operating Motor Operated Valves (MOV). This is an intermittent duty application.

The issue was identified on Eaton Starter Model AN56DN*, AN56GN*, CN55DN*, CN55GN* style starters and contactors with supplied date codes T4514 (week 45 of year 2014) and T4215 (week 42 of year 2015). Paragon is in the process of identifying the date codes to provide the specific information to the identified plants.

The following plants were supplied starters from September 2014 through October 2018: Beaver Valley, Columbia, Ergytech, Harris, Millstone, NEK KRSKO, North Anna, Prairie Island.

The component design that exhibited the failure was revised by the original equipment manufacturer (Eaton) in October 2018. There have been no reported failures of the interlock mechanism in vintages manufactured before September 2014 or after October 2018.

These recommendations are based on the specific application: The reversing starters and reversing contactors are typically wired in a configuration that will electrically lock out one of the contactors when the other one is being energized to prevent both contactors from being energized at the same time. Therefore, the mechanical interlock is not required to prevent both contactors from being closed at the same time when the electrical interlock configuration is being implemented. In this scenario, the mechanical interlocks are not required and can be removed.

The motor control centers that contain the mechanical interlock should be monitored to ensure that there is no binding during operation.

The evaluation being performed by Paragon is expected to be completed by May 29, 2021.

Tracy Bolt
Chief Nuclear Officer, CNO
817-284-0077
Paragon Energy Solutions, LLC
7410 Pebble Drive
Ft. Worth, TX 76118

* * * UPDATE ON AT 1559 EDT ON 5/3/2021 FROM TRACY BOLT TO BRIAN LIN * * *
The following revision was received from Paragon Energy Solutions via email and corrects the identified date code and includes the size and serial number of the starter that failed:

The issue was identified on supplied Size 1, 73262-025-00028 (Date Code: T4515 - 45th week of 2015) and Size 2, 73262-028-00001 (Date Code: T4215 - 42nd week of 2015).

Notified R1DO (Young), R2DO (Miller), R3DO (Orlikowski), R4DO (Deese), NMSS Events Notification, and Part 21 Group via email.


Power Reactor
Event Number: 55224
Facility: Peach Bottom
Region: 1     State: PA
Unit: [2] [] []
RX Type: [2] GE-4,[3] GE-4
NRC Notified By: Matthew George
HQ OPS Officer: Ossy Font
Notification Date: 04/30/2021
Notification Time: 07:38 [ET]
Event Date: 04/29/2021
Event Time: 23:54 [EDT]
Last Update Date: 04/30/2021
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(v)(D) - Accident Mitigation
Person (Organization):
SCHROEDER, DAN (R1)
Power Reactor Unit Info
Unit SCRAM Code RX Crit Initial PWR Initial RX Mode Current PWR Current RX Mode
2 N Y 100 Power Operation 100 Power Operation
Event Text
HIGH PRESSURE COOLANT INJECTION (HPCI) DECLARED INOPERABLE

"On 4/29/21 at 2354 [EDT], an alarm was received for U2 HPCI Inverter Power Failure. [It was] identified that the High Pressure Coolant Injection (HPCI) flow controller had lost power due to a failure of an inverter. Without the flow controller, HPCI would not auto start to mitigate the consequences of an accident; thus, HPCI was declared inoperable. All other emergency core cooling systems and reactor core isolation cooling (RCIC) system remain operable.

"HPCI is a single train system with no redundant equipment in the same system; therefore, this failure is reportable as an event or condition that could have prevented fulfillment of a safety function needed to mitigate the consequences of an accident per 10CFR50.72(b)(3)(v)(d).

"The NRC Resident has been informed of this notification."


Power Reactor
Event Number: 55229
Facility: Catawba
Region: 2     State: SC
Unit: [2] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Scott Milton
HQ OPS Officer: Joanna Bridge
Notification Date: 05/01/2021
Notification Time: 15:39 [ET]
Event Date: 05/01/2021
Event Time: 07:55 [EDT]
Last Update Date: 05/01/2021
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
Person (Organization):
MILLER, MARK (R2)
Power Reactor Unit Info
Unit SCRAM Code RX Crit Initial PWR Initial RX Mode Current PWR Current RX Mode
2 A N 0 Hot Standby 0 Hot Standby
Event Text
AUTOMATIC REACTOR TRIP AND ACTUATION OF THE AUXILIARY FEEDWATER SYSTEM

"At 0755 EDT, on May 1, 2021, with Unit 2 in Mode 3 at 0 percent (not critical) power, the reactor trip breakers opened during heat-up activities. The trip was not complex, with all systems responding normally post-trip. At 1013 EDT, on May 1, 2021, with Unit 2 in Mode 3 at 0 percent power, an actuation of the Auxiliary Feedwater (AFW) System occurred. The loss of both main feedwater pump turbines caused an AFW auto-start. The 2A and 2B motor driven auxiliary feedwater (MDAFW) pumps automatically started as designed when the loss of both main feedwater pumps signal was received. The cause of the actuation is still being evaluated.

"Operations responded and stabilized the plant. Decay heat is being removed by the steam generators and discharging steam to the condenser. Unit 1 is not affected.

"Due to the Reactor Protection System (RPS) actuation while not critical and the actuation of the AFW system, this event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A).

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


Fuel Cycle Facility
Event Number: 55216
Facility: Global Nuclear Fuel - Americas
Region: 2     State: NC
Unit: [] [] []
RX Type: Uranium Fuel Fabrication
Comments: Leu Conversion (Uf6 To Uo2)
Leu Fabrication
Lwr Commerical Fuel
NRC Notified By: Philip Ollis
HQ OPS Officer: Brian Lin
Notification Date: 04/27/2021
Notification Time: 16:21 [ET]
Event Date: 04/26/2021
Event Time: 18:22 [EDT]
Last Update Date: 04/27/2021
Emergency Class: Non Emergency
10 CFR Section:
PART 70 APP A (c) - Offsite Notification/News Rel
Person (Organization):
NMSS_EVENTS_NOTIFICATION (EMAIL)
MILLER, MARK (R2DO)
Event Text
EN Revision Imported Date: 5/4/2021

EN Revision Text: OFFSITE NOTIFICATION

"At approximately 1822 EDT on April 26th, the New Hanover County Deputy Fire Marshal was notified that the outer fire doors on the first and third floor of the Dry Conversion Process (DCP) elevator shaft malfunctioned and were left in the open position to allow for the elevator repair contractor to observe the issue. The DCP elevator is located on the South wall of DCP which is a credited fire barrier. A fire watch was initiated and maintained until the elevator doors were restored to service at approximately 1330 EDT on April 27th. The New Hanover County Fire Marshal was notified at 1410 EDT that the doors were returned to operational status and that the fire watch had been terminated. Because the New Hanover County Deputy Fire Marshall was notified, a concurrent notification to the NRC Operations Center is being made per 10 CFR 70, Appendix A(c)."

NRC Region 2 and the North Carolina Radiation Protection Office will be notified of this event.


Agreement State
Event Number: 55217
Rep Org: ARIZONA DEPT OF HEALTH SERVICES
Licensee: Ninyo & Moore
Region: 4
City: Phoenix   State: AZ
County:
License #: 07-460
Agreement: Y
Docket:
NRC Notified By: Brian Goretzki
HQ OPS Officer: Brian Lin
Notification Date: 04/27/2021
Notification Time: 18:48 [ET]
Event Date: 04/26/2021
Event Time: 00:00 []
Last Update Date: 04/27/2021
Emergency Class: Non Emergency
10 CFR Section:
Agreement State
Person (Organization):
PROULX, DAVID (R4DO)
NMSS_EVENTS_NOTIFICATION, (EMAIL)
ILTAB, (EMAIL)
CNSNS (MEXICO), - (EMAIL)
Event Text
EN Revision Imported Date: 5/4/2021

EN Revision Text: AGREEMENT STATE REPORT - STOLEN GAUGE

The following information was received from the Arizona Department of Health Services (the Department) via email:

"The Department received notification from the licensee that a portable gauge was stolen. A technician locked a portable gauge in the back of a truck and the truck was locked inside the users garage at their home overnight. When the gauge user came out to go to work the next day, the chain had been cut and the gauge and the gauge transport box were missing. The gauge is a Troxler 3430, Serial Number 34160, containing approximately 8 millicuries of Cesium-137 and 40 millicuries of Americium-241:Beryllium. A police report has been filed. The Department has requested additional information and continues to investigate the event."

Arizona Incident No.: 21-004

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


Fuel Cycle Facility
Event Number: 55218
Facility: Nuclear Fuel Services Inc.
Region: 2     State: TN
Unit: [] [] []
RX Type: Uranium Fuel Fabrication
Comments: Heu Conversion & Scrap Recovery
Naval Reactor Fuel Cycle
Leu Scrap Recovery
NRC Notified By: Nick Brown
HQ OPS Officer: Brian Lin
Notification Date: 04/27/2021
Notification Time: 19:36 [ET]
Event Date: 04/27/2021
Event Time: 17:30 [EDT]
Last Update Date: 04/27/2021
Emergency Class: Non Emergency
10 CFR Section:
PART 70 APP A (c) - Offsite Notification/News Rel
Person (Organization):
MILLER, MARK (R2DO)
PROULX, DAVID (R4DO)
NMSS_EVENTS_NOTIFICATION, (EMAIL)
FUELS GROUP, - (EMAIL)
Event Text
EN Revision Imported Date: 5/4/2021

EN Revision Text: CONCURRENT REPORT - IMMEDIATE REPORT TO THE TEXAS DEPARTMENT OF STATE HEALTH SERVICES

"Low level waste shipment bound for WCS [(Waste Control Specialists)], Andrews, Texas was involved in a minor traffic accident. The trailer sustained light damage to the rear of the trailer. No damage to the shipment contents was identified during visual inspection. Driver was released by the officer working the accident. Accident occurred near Dallas, Texas. The licensee notified the NRC Resident Inspector."


Power Reactor
Event Number: 55231
Facility: Fermi
Region: 3     State: MI
Unit: [2] [] []
RX Type: [2] GE-4
NRC Notified By: Jeff Myers
HQ OPS Officer: Brian Lin
Notification Date: 05/03/2021
Notification Time: 15:39 [ET]
Event Date: 05/03/2021
Event Time: 09:30 [EDT]
Last Update Date: 05/03/2021
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(ii)(B) - Unanalyzed Condition
Person (Organization):
ORLIKOWSKI, ROBERT (R3)
Power Reactor Unit Info
Unit SCRAM Code RX Crit Initial PWR Initial RX Mode Current PWR Current RX Mode
2 N Y 100 Power Operation 100 Power Operation
Event Text
UNANALYZED CONDITION
"At 0930 EDT on 5/3/2021, it was determined that during entries into the Fermi 2 Reactor Building Steam Tunnel (RBST) on 4/17/2021, 4/18/2021, and 4/21/2021 that the door was not controlled according to site procedures. The RBST door is credited as a hazard barrier for various high-energy line break (HELB) scenarios. On the identified dates, the RBST door was left open for brief periods during maintenance related activities in the RBST. This condition is not bounded by existing analyses as the door is assumed to be closed throughout a HELB event. The time period that the door was open was less than one hour in each case, as stay times in the room are inherently limited by industrial and radiological conditions. Individuals remained in the area to close the door if needed, but existing analyses do not address the ability to perform those actions under all HELB scenarios.

"There is no impact to the health and safety of the public or plant personnel as the door is currently closed and latched and access into the area has been restricted to normal ingress and egress per site procedures, which ensures consistency with existing analyses. Therefore, this event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(ii)(B). Investigation into the cause is ongoing. Preliminary review of the extent of this condition identified entries into the RBST on other occasions during the past three years where the conditions may also have not been bounded by existing analyses. The additional occasions where the door may have been held open were on 9/22/2018 (MODE 3), 10/26/2018 (MODE 1 ), 11/2/2018 (MODE 1), and 3/21/2020 (MODE 3). Each of these instances was also less than one hour with the exception of the occurrence beginning on 10/26/2018 which lasted approximately 10 hours to support packing leak repairs on a HPCI [High Pressure Coolant Injection] Outboard Isolation Valve."

The licensee notified the NRC Resident Inspector.