ENS 44306
ENS Event | |
|---|---|
19:12 Jun 18, 2008 | |
| Title | 24-Hr Certificate of Compliance Violation Report |
| Event Description | Entergy discovered on June 18, 2008 at 1412 that, due to an error in the Cask Loader Database, four spent fuel casks were loaded in a manner not in compliance with the Certificate of Compliance (CofC). As discussed below, this event is not safety significant since all cask design limits (e.g., heat load, radiation levels, and criticality) continue to be met although some specific spent fuel assemblies loaded were outside of the conservative individual fuel assembly limits specified in the CofC.
Specifically, during a data update of the Cask Loader Database, it was discovered that four HI-STORM 100 model casks had been loaded with spent fuel bundles that exceeded the Certificate of Compliance (CoC) limits. The four casks involved are F16D003AD, F16D003AE, F16D003AF, and F16D003AG. Verification of the database has determined that 34 of fuel assemblies loaded in these four casks exceeded the maximum allowed Decay Heat per Fuel Storage Location Limit and/or the Fuel Burnup Limit as specified in the CofC Section 2.4 when the assemblies were loaded into the casks. This condition is reportable in accordance with CofC Section 22. CAUSE: The preliminary cause is an error in the Cask Loader Database. The database had incorrect bundle exposures for these assemblies. The Cask Loader Database is used to select fuel to load in each cask. The assembly exposures in the Cask Loader Database are used to ensure assemblies selected for loading into fuel casks meet the applicable exposure and cooling time limits provided in the Certificate of Compliance. SAFETY SIGNIFICANCE: It has been verified that currently the decay heat loads for all assemblies are less than the CofC limits. All casks are below the cask total heat load limit of 28.19 kW and all cooling features for the casks are functioning properly. Since the total heat loads in the casks are below the required limits, the structural integrity of the casks is not challenged. A preliminary evaluation of the as loaded configurations was performed on the four casks. This evaluation concludes that fuel cladding in the affected casks is not adversely affected since the fuel cladding temperature will not exceed the fuel cladding design limit of 400 degrees centigrade. Furthermore, the fuel assembly exposure assumed in the dose calculations bounds the exposure of the loaded fuel assemblies. Radiation levels of stored casks are within Cask Technical Specification limits and there are no radiation anomalies. Reactivity parameters are not affected by the errors identified. There has been no impact on occupational dose and all surveillance parameters are within acceptance limits. All four casks are currently considered operable and performing their intended safety function. The licensee informed the NRC Resident Inspector. |
| Where | |
|---|---|
Grand Gulf  Mississippi (NRC Region 4) | |
| Reporting | |
| Other Unspec Reqmnt | |
| Time - Person (Reporting Time:+17.77 h0.74 days <br />0.106 weeks <br />0.0243 months <br />) | |
| Opened: | Ricky Patterson 12:58 Jun 19, 2008 |
| NRC Officer: | Steve Sandin |
| Last Updated: | Jun 19, 2008 |
| 44306 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 443062008-06-18T19:12:00018 June 2008 19:12:00
[Table view]Other Unspec Reqmnt 24-Hr Certificate of Compliance Violation Report 2008-06-18T19:12:00 | |