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| Start date | Report date | Site | Reporting criterion | System | Event description | |
|---|---|---|---|---|---|---|
| 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 40897 | 24 July 2004 17:00:00 | San Onofre | 10 CFR 72.75(c)(1), ISFSI Defect | On July 24, 2004, at about 1000 PDT, SCE (Southern California Edison) personnel were tightening two seismic restraint bolts on Advanced Horizontal Storage Module (AHSM) Number 10 at the Unit 1 ISFSI (Independent Fuel Storage Installation) when one of the bolts failed. SCE had placed the storage canister into AHSM No. 10 on July 18, 2004 and was tightening the restraint as specified in the final safety analysis report, after the module had reached thermal equilibrium. SCE plans to replace the failed bolt with another bolt manufactured under the same Certificate of Compliance and will tighten the seismic restraints within the period allowed by the FSAR (one week from initial placement of the storage canister). SCE's evaluation of the failed bolt is ongoing. SCE has notified the NRC resident inspectors about this occurrence and will provide them with a copy of this report. |