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| Start date | Report date | Site | Reporting criterion | System | Event description | |
|---|---|---|---|---|---|---|
| ENS 54075 | 20 May 2019 22:33:00 | Summer | 10 CFR 72.75(d)(1), ISFSI Safety System Functional Failure | At approximately 1833 EDT on 5/20/2019, VC Summer Nuclear Station identified a potential missed surveillance of the Spent Fuel Storage Canister Heat Removal System Surveillance Requirement (SR) 3.1.2. This is a surveillance requirement in the Holtec CoC No. 1032 Amendment 0, Revision 1 for the HI-STORM FW. It was identified that the station suspended verifying all overpack inlets and outlets were free of blockage from solid debris or floodwater every 24 hours and began utilizing the alternate surveillance method of installed temperature monitoring equipment. However, this monitoring equipment had not been declared operable from the completion of the Dry Cask Storage Campaign on April 11, 2019. This surveillance was last performed satisfactorily on May 15, 2019. The station has documented this missed surveillance in the Corrective Action Program under CR-19-01866. The NRC Senior Resident has been notified. The licensee stated that the temperature monitoring equipment while not operable, was functional. The licensee successfully performed the surveillance requirement on 5/21/2019.
ENS Event Number 54075, made on May 21, 2019, is being retracted. NRC Notification 54075 was made to ensure the 24-Hour Non-Emergency reporting requirement of 10 CFR 72.75(d)(1)(i) was met for a potential missed surveillance of the Spent Fuel Storage Canister Heat Removal System Surveillance Requirement (SR) 3.1.2. On June 4, 2019, a Past Operability Evaluation determined the temperature monitoring equipment, utilized to complete the Technical Specification Surveillance 3.1.2, was operable during the time period of 5/16/2019-5/21/2019. The station performed satisfactory calibration checks on the temperature monitoring equipment and had not experienced any significant weather events capable of producing vent blockage (i.e. flood, tornado, snow storm, etc.). Therefore, utilizing the installed temperature monitoring equipment is not considered a missed surveillance of SR 3.1.2 and renders this event not reportable under 10 CFR 72.75(d)(1)(i). VCSNS's evaluation of this event is documented in the Corrective Action Program in Condition Report (CR-19-01866). The licensee has notified the NRC Resident Inspector. Notified R2DO (Rose) and NMSS Events Notification (email). | ||
| ENS 53858 | 1 February 2019 22:05:00 | Southern California Edison Company | 10 CFR 72.75(d)(1), ISFSI Safety System Functional Failure | EN Revision Text: NO SEISMIC ANALYSIS FOR CANISTER TRANSPORT PROCESS During follow-up reviews resulting from the Aug. 3, 2018 canister downloading event (EN#53605), Southern California Edison (SCE) became aware of a condition where, during short periods of the canister transport process, the Vertical Cask Transporter (VCT) could have been operated without a supporting seismic analysis while transporting loaded canisters for storage. SCE has decided to conservatively report this issue. The VCT is a mobile gantry crane that is used to transport and download fuel canisters into an Independent Spent Fuel Storage Installation (ISFSI) enclosure. Twenty-nine canisters have been downloaded into the San Onofre nuclear plant ISFSI in this manner since January, 2018. The Holtec UMAX Certificate of Compliance requires that lifting of a loaded spent fuel canister must be performed with redundant (i.e., single-failure-proof) load drop protection features. Inherent in the definition is the ability to withstand seismic loading. SCE identified that although applicable rigging and downloading procedures were followed, a supporting seismic analysis should be developed for the short duration periods in the process where the canisters are transitioned to rigging. Southern California Edison has directed its vendor, Holtec, to perform this further seismic analysis. While the additional analysis may conclude that the VCT is stable and functional during these transitioning periods, SCE will work with the vendor should modifications to the canister transport process become necessary. SCE is making this notification in accordance with the requirements of 10 CFR 72.75(d)(1). There was no seismic event that resulted in damage to the VCT or a spent fuel canister during the fuel transfer campaign. All 29 spent fuel canisters are currently in safe storage within the ISFSI.
On 4/2/19, Southern California Edison (SCE) is retracting San Onofre Nuclear Generating Station (SONGS) Event Report 53858 dated February 2, 2019 for the Independent Spent Fuel Storage Installation (ISFSI). SCE conservatively submitted the event report under 72.75(d)(1) after it was initially determined the Vertical Cask Transporter (VCT) may have been operated for short periods of time during the canister transport process without a supporting seismic evaluation, contrary to the requirements of the Certification of Compliance (COC). A revision to the calculation by the vendor has subsequently confirmed the transport process and VCT operation met the seismic requirements of the Holtec COC. Therefore, Event Report No. 53858 is retracted. Notified R4DO (Gaddy) and via E-mail IRD MOC (Kennedy) and NMSS Events Notification E-mail group. | ||
| ENS 53798 | 19 December 2018 08:00:00 | Southern California Edison Company | 10 CFR 72.75(d)(1), ISFSI Safety System Functional Failure | As part of the reviews following the August 3rd 2018 canister downloading event (EN#53605), SCE has identified events where the HI-PORT may have been operated outside the analytical assumptions of the seismic analysis while transporting a loaded canister in the HI-TRAC. SCE has decided to conservatively report this issue. The HI-PORT is subject to requirements in the Certificate of Compliance that result in seismic restrictions on center of gravity and proximity to structures that could adversely affect the function of the HI-PORT along the haul route. SCE has concluded that during previous movements of loaded spent fuel canisters during 2018, the HI-PORT likely exceeded these procedural and analytical limits in some cases. Additional analysis is underway that may conclude that damage to the HI-PORT would not occur under these conditions. Nevertheless, this situation is being reported in accordance with 10CFR72.75(d)(1) for an important to safety component that was disabled or failed to function. There was no seismic event that resulted in damage to the HI-PORT during the fuel transfer campaign. All 29 spent fuel canisters are currently in safe storage within the ISFSI. NRC Region IV will be notified as SONGS does not have a NRC Resident Inspector. | ||
| ENS 53605 | 3 August 2018 08:00:00 | Southern California Edison Company | 10 CFR 72.75(d)(1), ISFSI Safety System Functional Failure | On Friday, August 3, (2018,) at approximately 1245 PST, Holtec International (a contractor for Southern California Edison (SCE)) was lowering a Multi-Purpose Canister (MPC) loaded with spent fuel into the Cavity Enclosure Container (CEC) of the SONGS Holtec UMAX Independent Spent Fuel Storage Installation (ISFSI) for purposes of dry storage. The canister was suspended from a Holtec Vertical Cask Transporter (VCT). During the download, the canister encountered an interference with the CEC divider shell and became bound in place. As a result, the downloader slings of the VCT became slack while the MPC was resting partially inside the CEC. Once Holtec became aware of the situation, the VCT towers were raised in order to restore tension in the rigging and to raise the MPC. The VCT was then adjusted, and the MPC was then safely lowered into the CEC and the rigging was disengaged. There was no effect on the integrity of the canister or release of radioactive material as a result of this event. This event meets the reporting criteria of 10CFR72.75(d)(1) in that the VCT, which is an important-to-safety component, was placed in a configuration which defeated its ability to perform its safety function. The VCT and associated rigging are described in Certificate of Compliance 1040, Technical Specification 5.2.c.3, which requires that lifting equipment shall have redundant drop protection features which prevent uncontrolled lowering of the load. By placing the VCT in the configuration of this event, the single-failure proof nature of the lifting devices was defeated. The VCT was no longer capable of mitigating the consequence of an accident, and there was no redundant equipment available and operable to perform the required safety function. SCE made an original determination that the event did not require a report. However, SCE contacted the NRC (Region IV) on Monday August 6th and again on Tuesday August 7th to provide details of the event. It has now been determined that the event is reportable under 10CFR72.75(d)(1) and this late report is being made. Licensee notified RIV (Simpson). | ||
| ENS 50787 | 4 February 2015 01:01:00 | Zion | 10 CFR 72.75(d)(1), ISFSI Safety System Functional Failure | On 2/3/2015 at 1901 (CST), equipment important to safety failed to function as designed: 33 NAC MAGNASTOR systems containing Spent Nuclear Fuel, and 1 NAC MAGNASTOR system containing GTCC (Greater than Class C) waste, had air inlet vent partial blockage, totaling 50 percent or greater, due to environmental conditions, i.e., snow. (Please Note, no VCC systems reached full blockage.) NO personnel radiation exposure. Actions Taken lAW the NAC FSAR, Rev. 5, which included actions to immediately return the systems to less than 50 percent blockage and ongoing maintenance activities to return all systems to full operability. Additional information: 1. On 2/4/2015 at 0445 hrs. All 34 failed systems were restored to less than 50 percent blockage. 2. lAW the NAC FSAR we have 30 days from time of discovery to return each system to full operability. 3. A report will be followed up within 60 days per 10 CFR 72.75.g The licensee will notify the NRC Inspector and the State of Illinois.
This phone notification is being made to retract an earlier '24 Hour Report' made on February 4, 2015 at 1815 CST, NRC event #50787. On February 4, 2015 at 1810 CST, Zion Station notified NRC that on February 3, 2015 at 1901 CST, Equipment Important To Safety failed to function as designed that being 33 NAC MAGNASTOR systems containing Spent Nuclear Fuel and 1 NAC MAGNASTOR containing GTCC waste had their Inlet vents partially blocked, totaling 50% or greater, due to environmental conditions, i.e. Snow. This appeared to meet criteria of Non-Emergency notification under 10 CFR 72.75d(1)(i). NAC International has provided documentation stating we have 58 hours to perform the immediate action to unblock the VCC vents to greater than 50% and 30 days to completely unblock all the vents. This documentation is attached to this notification. Upon further review by Exelon Management, Zion Solutions Management and NAC, using criteria established in Sections 4.3.7.1 and 12.2.2 of the SER for CoC 72-1031, Amendment 0, no limits were exceeded. Actions were immediately initiated to restore the 34 failed systems to less than 50% blockage and were completed in less than 10 Hours. This is well within the 58 hour SAR basis. This is the basis for retracting the notification. Based on the above, (the licensee) management concludes this event does not meet the 24-hour reporting criteria established in 10 CFR 72.75d(1)(i). The R3DO(Pelke) was notified. | ||
| ENS 49263 | 10 August 2013 09:30:00 | Ppl Susquehanna Llc | 10 CFR 72.75(c)(2), ISFSI Degradation 10 CFR 72.75(d)(1), ISFSI Safety System Functional Failure | |||
| ENS 48965 | 24 April 2013 17:02:00 | Pacific Gas & Electric | 10 CFR 72.75(d)(1), ISFSI Safety System Functional Failure | On April 24, 2013, at 09:02 PDT, Diablo Canyon Power Plant (DCPP) determined that the loading procedure for the independent spent fuel storage installation (ISFSI) multi-purpose canisters (MPCs) placed the MPCs in an unanalyzed condition. The procedure (approved for use in 2009) contained steps to install vent caps on the MPC vents while the MPC contained an air/water mixture. This placed the MPC in an isolated condition without any relief path while water was in the MPC (a condition previously not analyzed in the DCPP ISFSI FSAR). The MPC vents that prevent MPC over pressurization were disabled while the vent caps were installed with no alternative over pressurization protection provided, therefore the condition is a 24-hour reportable event under 10 CFR 72.75(d)(1). This process was used for 23 casks, beginning in 2009. The amount of time each cask was isolated was approximately 40 - 60 minutes. DCPP expects that no appreciable MPC pressure increase occurred, since the MPC contains an air void, and the activity is performed expeditiously. Based on engineering judgment, a conservative evaluation of the potential pressure rise during this period shows an increase of less than 2 psig. Since the MPC is vented prior to isolation, a 2 psig increase does not challenge the MPC design pressure of 100 psig. Therefore, there is no reason to believe that the integrity of any of the 23 previously loaded MPCs has been challenged at the DCPP ISFSI. This evaluation will be confirmed and documented in a formal calculation as part of issue resolution. The licensee has notified the NRC Resident Inspector. | ||
| ENS 47406 | 3 November 2011 16:39:00 | Fort Saint Vrain | 10 CFR 72.75(d)(1), ISFSI Safety System Functional Failure | At 1009 (all times MDT) today, 11/3/11, a Security Officer performing routine rounds noted 95-100% blockage on the inlet screens at the Fort St. Vrain Independent Spent Fuel Storage Installation (FSV ISFSI). The FSV ISFSI is located near Platteville, Colorado. The FSV ISFSI safely stores used fuel from the Fort St. Vrain Nuclear Generating Station (FSV NGS). The NGS has been decommissioned and released for unrestricted use. The fuel is stored at the ISFSI under NRC license SNM-2504. The inlet screens are in place to provide a cooling path for the used fuel. The Security Officer immediately notified the Emergency Coordinator, who directed the screens to be cleared of the blockage at 1010. The blockage was removed at 1021, at which time the event was terminated. The blockage was caused by frost, which built up due to dense fog, high humidity, and low temperatures. Removal was accomplished by lightly hitting the screens by hand. No further action is necessary. Per FSV ISFSI Limiting Condition for Operation (LCO) 3.1, inlet screen blockage which equals or exceeds 95 percent must be cleared within 24 hours. The blockage was cleared in 12 minutes. Thus the REQUIRED ACTION was satisfactorily completed, and the CONDITION was exited. Per the FSV ISFSI Emergency Plan Implementing Procedure (EPI)-102, Emergency Action Level 1NE.6, 95% or greater blockage of the inlet screens constitutes a 1 hour NON-EMERGENCY event. Required notifications were made by the Warning Communications Center (WCC) in Idaho. There was no increase in building temperature during this event. | ||
| ENS 46391 | 3 November 2010 13:13:00 | Cooper | 10 CFR 72.75(d)(1), ISFSI Safety System Functional Failure | At 0813 (CDT), the Cooper Nuclear Station (CNS) Control Room (CR) received a report of a partial neutron water shield drain down on the Dry Fuel On-site Transfer Cask (TC). The TC, with a loaded Dry Storage Cask (DSC), was located in the Reactor Building (RB) Railroad Airlock area. Final preparations were being completed prior to transferring the DSC to Horizontal Storage Module (HSM) 2A. The RB and south side of the Administration Building were cleared of unnecessary personnel. No abnormally elevated RB area radiological readings were noted on CR indication. Local indication in the (Railroad) Airlock from portable radiation monitors indicated abnormally high readings due to the drain down. At 0819 (CDT), CNS entered Abnormal Procedure 5.1 RAD, Building Radiation Trouble. Surveys indicate the top of the TC had readings of about 130 mR/hr neutron at 30cm, which is above the normal readings of 2 mR/hr. Surveys of the bottom portion of the TC indicated a neutron dose rate of 10 mR/hr at 30cm. Actions per 5.1 RAD were subsequently performed. An emergency declaration was not required, because no confinement boundary was adversely affected and neutron levels did not meet a factor of 1,000 over normal levels. Since dose rates were no greater than noted above, and because neutron dose was being directed upward due to the shielding loss being in the upper portion of transfer cask, the Technical Support Center (TSC), which is located in the Administration Building, was determined to support habitability. Furthermore the TSC is provided with additional shielding for personnel protection during an event. This is being reported as a 24 hour report under 10 CFR 72.75(d) for an important to safety fuel storage equipment that failed to function as designed when required to prevent releases, prevent exposures in excess of regulatory limits, or mitigate the consequences of an accident and no redundant equipment was available or operable to perform the required safety function. The cause of the drain down is under investigation. The licensee notified the NRC Resident Inspector. |