ENS 52342
From kanterella
Jump to navigation
Jump to search
ENS Event | |
|---|---|
14:34 Nov 2, 2016 | |
| Title | Unanalyzed Condition for Control Rod Drop Accident at Low Power |
| Event Description | On November 2, 2016, while performing a re-evaluation of the radiological consequences of the Fermi 2 control rod drop accident (CRDA), DTE Electric Company (DTE) identified a non-conservatism in the current Fermi 2 design and licensing basis of the CRDA. As described in the Updated Final Safety Analysis Report (UFSAR) Section 15.4.9, the current design and licensing basis assumes that the post-CRDA release pathway consists of carryover with steam to the turbine condenser. The re-evaluation has identified that a forced release from the gland seal exhausters (GSEs) could also occur which could result in post-CRDA radiological consequences that exceed the current 10 CFR 100.11 offsite dose limits and Standard Review Plan 6.4 (General Design Criterion 19) main control room dose limits when operating at low power conditions.
The unanalyzed condition described above only applies to low power operating conditions (i.e. less than 10% power) since the fuel damage postulated as a result of a CRDA is only credible under low power operating conditions when an individual control rod worth is high. Fermi 2 is currently at 97% power and, therefore, the plant condition is currently bounded by the design and licensing basis such that the condition currently does not exist and no immediate actions are required. However, Fermi 2 has operated at low power levels several times in the past three years. Those periods of operation at low power represent unanalyzed conditions that significantly degraded plant safety since the occurrence of a CRDA during those periods could have resulted in offsite and main control room doses exceeding regulatory limits. Therefore, this 8-hour notification is being reported in accordance with 10 CFR 50.72(b)(3)(ii)(B). There was no adverse impact to public health and safety or to plant employees. The licensee has notified the NRC Resident Inspector. |
| Where | |
|---|---|
Fermi  Michigan (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition | |
| Time - Person (Reporting Time:+0.52 h0.0217 days <br />0.0031 weeks <br />7.12296e-4 months <br />) | |
| Opened: | Greg Miller 15:05 Nov 2, 2016 |
| NRC Officer: | John Shoemaker |
| Last Updated: | Nov 2, 2016 |
| 52342 - 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 52342\u003C/a\u003E - \u003Ca href=\"/Fermi\" title=\"Fermi\"\u003EFermi\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EUnanalyzed Condition for Control Rod Drop Accident at Low Power\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 52342 - Fermi\n","link":"","lat":41.96295277777778,"lon":-83.25779444444444,"icon":"/w/images/5/5b/DTE_Energy_icon.png"}],"imageoverlays":null} | |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (97 %) |
| After | Power Operation (97 %) |
WEEKMONTHYEARENS 552312021-05-03T13:30:0003 May 2021 13:30:00
[Table view]10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition ENS 537122018-11-01T04:00:0001 November 2018 04:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition En Revision Imported Date 12/31/2018 ENS 536742018-10-19T04:00:00019 October 2018 04:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Low Pressure Core Injection Pumps Incapable of Automatic Startup ENS 527242017-05-02T21:00:0002 May 2017 21:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition for Combustion Turbine Generator Configuration ENS 523422016-11-02T14:34:0002 November 2016 14:34:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition for Control Rod Drop Accident at Low Power ENS 522142016-08-31T23:50:00031 August 2016 23:50:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition with a Potential Tornado ENS 522022016-08-25T20:29:00025 August 2016 20:29:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Mechanical Draft Cooling Tower Declared Inoperable ENS 514402015-10-02T12:25:0002 October 2015 12:25:00 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 Loose Safety Relief Valve Discharge Flange Bolts ENS 422242005-12-23T03:25:00023 December 2005 03:25:00 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 Eecw Temperature Control Valve Not Fully Open ENS 418472005-07-18T02:31:00018 July 2005 02:31:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition of Maintenance Bus Tie Breakers ENS 418162005-06-30T23:31:00030 June 2005 23:31:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Unanalyzed Condition Related to the Standby Feedwater Pumps and Control Circuits ENS 417142005-05-18T22:50:00018 May 2005 22:50:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Identification of Design and Operating Procedure Deficiencies Related to Appendix R Events ENS 415512005-03-30T21:00:00030 March 2005 21:00:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition Identification of Design and Operating Procedure Deficiencies 2021-05-03T13:30:00 | |
Retrieved from "https://kanterella.com/w/index.php?title=ENS_52342&oldid=420792"