ENS 50639
From kanterella
Jump to navigation
Jump to search
ENS Event | |
|---|---|
17:00 Nov 25, 2014 | |
| Title | Non-Conservatisms in Methodology Used for Emergency Core Cooling System Performance Requirements |
| Event Description | On Tuesday, November 25, 2014, at 1200 EST, the FirstEnergy Nuclear Operating Company (FENOC) reviewed AREVA 10CFR50.46 Notification Letter FAB14-00625 for the Davis-Besse Nuclear Power Station (DBNPS). This letter indicates that certain non-conservatisms were discovered in the methodology application and inputs used by AREVA for nuclear fuel core configurations with Mark-B-HTP fuel when operated under certain conditions. When corrected, this increases the Peak Cladding Temperature (PCT) in excess of the value prescribed in 10CFR50.46(b)(1) under Loss of Coolant Accident (LOCA) conditions. The DBNPS reactor core contains Mark-B-HTP fuel. 10CFR50.46 paragraph (b) defines the acceptance criteria for the LOCA analysis process. The DBNPS licensing basis PCT is evaluated for compliance with and must not exceed the criterion prescribed in 10CFR50.46(b)(1).
AREVA had provided compensatory measures in terms of plant axial imbalance limits and Fq linear heat rate limits associated with reductions in LOCA linear heat rates so that the DBNPS operates within 50.46 limits. FENOC implemented the compensatory measures at the DBNPS on October 23, 2014, per AREVA recommendations, and as a result the errors reported have no impact on current plant operation or public health and safety. Preliminary analysis of past operating conditions indicate that the DBNPS did not exceed the 50.46(b)(1) criteria for PCT. This 8-hour notification is being reported in accordance with 10CFR50.72(b)(3)(ii)(B). Based on 50.46(a)(3)(ii) criteria, FENOC will submit a report within 30 days for the DBNPS. FENOC has notified the DBNPS NRC Senior Resident Inspector. |
| Where | |
|---|---|
Davis Besse  Ohio (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| LER: | 05000346/LER-2014-004 Regarding Deficiency in Loss of Coolant Accident Analysis Adversely Affected Predicted Peak Cladding Temperature |
| Time - Person (Reporting Time:+-0.47 h-0.0196 days <br />-0.0028 weeks <br />-6.43806e-4 months <br />) | |
| Opened: | Tom Phillips 16:32 Nov 25, 2014 |
| NRC Officer: | Daniel Mills |
| Last Updated: | Nov 25, 2014 |
| 50639 - NRC Website
Loading map... {"minzoom":false,"maxzoom":false,"mappingservice":"leaflet","width":"350px","height":"250px","centre":false,"title":"","label":"","icon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"zoom":6,"defzoom":14,"layers":["OpenStreetMap"],"image layers":[],"overlays":[],"resizable":false,"fullscreen":false,"scrollwheelzoom":true,"cluster":false,"clustermaxzoom":20,"clusterzoomonclick":true,"clustermaxradius":80,"clusterspiderfy":true,"geojson":"","clicktarget":"","imageLayers":[],"locations":[{"text":"\u003Cb\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003E\u003Ca class=\"mw-selflink selflink\"\u003EENS 50639\u003C/a\u003E - \u003Ca href=\"/Davis_Besse\" title=\"Davis Besse\"\u003EDavis Besse\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003ENon-Conservatisms in Methodology Used for Emergency Core Cooling System Performance Requirements\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 50639 - Davis Besse\n","link":"","lat":41.59545,"lon":-83.08950833333333,"icon":"/w/images/7/78/Cleveland_Electric_icon.png"}],"imageoverlays":null}       | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 573732024-10-10T14:45:00010 October 2024 14:45:00
[Table view]10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition ENS 553212021-06-22T16:08:00022 June 2021 16:08:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition High-Energy Line Break Door Unable to Be Latched ENS 528652017-07-20T16:30:00020 July 2017 16:30:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Potential Tornado Missile Vulnerabilities ENS 520102016-06-16T15:37:00016 June 2016 15:37:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition of Emergency Diesel Generator During Tornado Low Pressure ENS 506392014-11-25T17:00:00025 November 2014 17:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Non-Conservatisms in Methodology Used for Emergency Core Cooling System Performance Requirements ENS 498282014-02-14T08:25:00014 February 2014 08:25:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Shield Building Construction Opening ENS 470962011-07-26T20:00:00026 July 2011 20:00:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Conditions Involving the Safety Related Direct Current (Dc) System ENS 416982005-05-13T20:00:00013 May 2005 20:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition - Electrical Containment Penetration ENS 404572004-01-19T16:20:00019 January 2004 16:20:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Certain Plant Doors May Not Be Able to Withstand Pressure Created by Main Steam Line Break ENS 402562003-10-17T13:00:00017 October 2003 13:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Steam and Feedwater Rupture Control System Unanalyzed Condition at Davis Besse 2024-10-10T14:45:00 | |
Retrieved from "https://kanterella.com/w/index.php?title=ENS_50639&oldid=421883"