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| Start date | Report date | Site | Reporting criterion | System | Event description | |
|---|---|---|---|---|---|---|
| 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 46373 | 27 October 2010 15:07:00 | Peach Bottom | 10 CFR 72.75(c)(2), ISFSI Degradation | On 10/27/10, at 1107 (EDT), troubleshooting of Independent Spent Fuel Storage Installation (ISFSI) Cask TN-68-01 identified that a helium leak exists in the cask lid sealing area at a leak rate greater than allowed by ISFSI Cask Technical Specification Section 3.1.3, Cask Helium Leak Rate. TS 3.1.3 limits the Cask Helium Leak Rate to 1.0 E-O5 ref-cc/sec. The cask was in LOADING OPERATIONS and is currently located within the (Peach Bottom Atomic Power Station) PBAPS Unit 2 containment building. Preliminary review indicates that a leak exists in the Cask Main Lid Outer Closure Seal. The cask will be repaired and tested prior to returning the cask to the Independent Spent Fuel Storage Installation (ISFSI). No release of radiation occurred as a result of this issue. This report is being submitted pursuant to 10CFR 72.75(c)(2) as a result of a reduction in the effectiveness of the cask confinement system. The Certificate of Compliance for this cask is 1027 (Amendment 0). The NRC Resident Inspector has been informed. | ||
| ENS 46353 | 22 October 2010 14:58:00 | Peach Bottom | 10 CFR 72.75(c)(1), ISFSI Defect 10 CFR 72.75(c)(2), ISFSI Degradation | On 10/22/10, at 1058 EDT, a troubleshooting of Independent Spent Fuel Storage Installation (ISFSI) Cask TN-50-A indicated that a leak existed in the cask lid sealing area at a rate greater than allowed by ISFSI Cask Technical Specification (TS) Section 3.1.3, Cask Helium Leak Rate. TS 3.1.3 limits the Cask Helium Leak Rate to 1.0 E-05 ref-cc/sec. The cask is currently in unloading operations and is located within the Peach Bottom Atomic Power Station Unit 3 containment building. Preliminary review indicates that a leak exists at the weld plug that provides sealing of the drilled interseal passageway associated with the drain port penetration of the cask lid. This leak effectively provides a bypass of the main lid outer confinement seal. This report if being submitted pursuant to 10CFR72.75(c)(1) as a result of a material defect in a weld in the cask main lid. This report is also being submitted pursuant to 10CFR72.75 (c) (2) as a result of a resolution in the effectiveness of the cask confinement system. The Certificate of Compliance for this cask is 1027 (Amendment 1). The NRC Resident Inspector has been informed of this notification.
On 10/27/10, at 1107 (EDT), troubleshooting of Independent Spent Fuel Storage Installation (ISFSI) Cask TN-68-01 identified that a helium leak exists in the cask lid sealing area at a leak rate greater than allowed by ISFSI Cask Technical Specification Section 3.1.3, Cask Helium Leak Rate. TS 3.1.3 limits the Cask Helium Leak Rate to 1.0 E-O5 ref-cc/sec. The cask was in LOADING OPERATIONS and is currently located within the (Peach Bottom Atomic Power Station) PBAPS Unit 2 containment building. Preliminary review indicates that a leak exists in the Cask Main Lid Outer Closure Seal. The cask will be repaired and tested prior to returning the cask to the Independent Spent Fuel Storage Installation (ISFSI). No release of radiation occurred as a result of this issue. This report is being submitted pursuant to 10CFR 72.75(c)(2) as a result of a reduction in the effectiveness of the cask confinement system. The Certificate of Compliance for this cask is 1027 (Amendment 0). The NRC Resident Inspector has been informed. Notified R1DO (Caruso), NRR EO (Thorp), NMSS EO (Lorson), and IRD (Grant). | ||
| ENS 41089 | 4 October 2004 21:30:00 | Haddam Neck | 10 CFR 72.75(c)(2), ISFSI Degradation | A significant reduction in the effectiveness of any spent fuel storage confinement system during use This reportability notification addresses a potential unanalyzed condition of 18 Transportable Storage Canisters (TSCs) which are loaded with spent nuclear fuel (SNF). Seventeen of these TSCs are stored in Vertical Concrete Casks (VCCs) at the Haddam Neck Plant Independent Spent Fuel Storage Installation (ISFSI). One TSC is currently in transport operations and will be transferred to the ISFSI in the near future. SNF clad temperature is affected by changes in the TSC internal environment that are encountered during fuel transfer operations. In order to maintain SNF clad temperatures within the analyzed limits, the time duration of certain fuel transfer activities are limited (for example, time in dewatering phase, time in vacuum drying phase and time in helium backfill phase). The canister dewatering section of CY procedures allowed multiple blowdowns of the TSC while in the dewatering time clock. This is contrary to the NAC thermal analysis which assumes a water environment in the canister during the dewatering period. It appears that this condition is not consistent with current analysis assumptions and is therefore a potential unanalyzed condition. NAC International (holder of the C of C) has been advised of this condition and is analyzing the TSC loading conditions. VCC outlet temperatures are within acceptable limits and there is no evidence of unusual radiation exposure in the ISFSI environs. |