ENS 40368
ENS Event | |
|---|---|
22:58 Dec 2, 2003 | |
| Title | Manual Scram Due to Low Reactor Water Feed Pump Suction Pressure |
| Event Description | On December 2, 2003, at 1658, a manual scram was inserted from 88% power, which is the maximum power due to the plant being in coastdown. The manual scram was inserted due to feedwater suction pressure being below the trip set point for the operation of the Turbine Driven Reactor Feed Pumps and Reactor Pressure Vessel water level trending down. The initiating event was the loss of the 480V Unit Sub 1I. All plant systems operated normally on the scram with the exception of those systems that lost power due to the tripping of 480V Unit Sub 1I.
The plant is shutdown at 0% power in Mode 3, maintaining pressure between 800 and 1065 psig, and reactor water level between level 3 and 8. Troubleshooting is in progress on the cause of the loss of the 480V Unit Sub 1I." Plant is identifying the loads lost during the loss of the 480V Unit Sub 1I and the cause of the low feedwater suction pressure. No additional specified system actuations occurred. No SRVs lifted and the electrical plant lineup is stable and in a normal lineup for plant conditions with the exception of the lost 480V bus. The licensee has notified the NRC Resident Inspector.
As a consequence of the manual reactor scram inserted at 1658 CST, reactor water lowered to Level 3. This level is a valid RPS actuation and containment isolation signal [Groups 2, 3 and 20]. These actuations are being reported consistent with 10CFR50.72(b)(3)(iv)(A). The Level 3 RPS actuation is expected during a high power reactor scram. Additionally, on December 2, 2003, at 1935 CST, a Level 3 RPS actuation reoccurred while transferring reactor coolant makeup from the Motor Driven Reactor Feed (MDRFP) to a Condensate/Condensate Booster Pump pair. Reactor pressure was being lowered to the discharge pressure of the Condensate/Condensate Booster pumps. This Level 3 is a valid RPS actuation and containment isolation signal. These actuations are being reported consistent with 10CFR50.72(b)(3)(iv)(A). The plant is shutdown at 0% power in Mode 3, maintaining pressure between 550 and 750 psig, and reactor water level between level 3 and 8. Troubleshooting is in progress on the cause of the loss of the 480V Unit Sub 1I. Both of these events will be reported as a single Licensee Event Report (LER). The plant continues to remove decay heat via the turbine bypass valves to the main condenser. The licensee will notify the NRC Resident Inspector. Notified R3DO Bruce Burgess. |
| Where | |
|---|---|
Clinton  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
| Time - Person (Reporting Time:+-3.35 h-0.14 days <br />-0.0199 weeks <br />-0.00459 months <br />) | |
| Opened: | Doug Hunter 19:37 Dec 2, 2003 |
| NRC Officer: | Jeff Rotton |
| Last Updated: | Dec 2, 2003 |
| 40368 - 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 40368\u003C/a\u003E - \u003Ca href=\"/Clinton\" title=\"Clinton\"\u003EClinton\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EManual Scram Due to Low Reactor Water Feed Pump Suction Pressure\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 40368 - Clinton\n","link":"","lat":40.17286111111111,"lon":-88.8332,"icon":"/w/images/b/be/Constellation_icon.png"}],"imageoverlays":null} | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | Yes, Manual Scram |
| Before | Power Operation (88 %) |
| After | Hot Shutdown (0 %) |
Clinton with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
WEEKMONTHYEARENS 563282023-02-01T05:43:0001 February 2023 05:43:00
[Table view]10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Scram Due to Turbine Trip ENS 541972019-08-03T07:26:0003 August 2019 07:26:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge En Revision Imported Date 8/7/2019 ENS 536982018-10-28T05:00:00028 October 2018 05:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram During a Reactor Shutdown ENS 536232018-09-26T05:00:00026 September 2018 05:00:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Undervoltage Condition Initiates an Automatic Start of the Diesel Generator ENS 531102017-12-09T19:48:0009 December 2017 19:48:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 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, 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material Manual Reactor Scram Due to Loss of Division 1 Ac Power to Numerous Components ENS 528002017-06-11T03:56:00011 June 2017 03:56:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Loss of Feedwater Heating ENS 527772017-05-31T01:38:00031 May 2017 01:38:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram ENS 499582014-03-26T00:42:00026 March 2014 00:42:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Loss of Condenser Vacuum ENS 496322013-12-13T23:57:00013 December 2013 23:57:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Trip During Feed Pump Swap ENS 496172013-12-09T02:27:0009 December 2013 02:27:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material Manual Scram Due to Loss of Division 1 480 Vac Power Causing Loss of Instrument Air to Containment and Scram Air Header ENS 489742013-04-26T13:55:00026 April 2013 13:55:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Rapidly Decreasing Level in the Ehc Oil Reservoir ENS 488122013-03-07T13:56:0007 March 2013 13:56:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram on Generator Trip/Turbine Trip ENS 475332011-12-18T15:30:00018 December 2011 15:30:00 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Loss of Rhr Cooling Due to Incorrect Reactor Water Level Indication ENS 474892011-11-29T23:28:00029 November 2011 23:28:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Unit Experienced an Automatic Reactor Scram During a Planned Shutdown ENS 454332009-10-15T10:37:00015 October 2009 10:37:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Reactor Recirculation Pump Trip ENS 439762008-02-11T04:07:00011 February 2008 04:07:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Manual Reactor Scram Due to Increasing Reactor Vessel Level ENS 428072006-08-27T22:05:00027 August 2006 22:05:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Reactor Trip Due to Reactor High Water Level ENS 424302006-03-20T10:53:00020 March 2006 10:53:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Main Turbine Trip Caused Reactor Scram ENS 408692004-07-14T05:45:00014 July 2004 05:45:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Rps and Containment Isolation Actuation Due to Low Rpv Level ENS 408682004-07-13T21:10:00013 July 2004 21:10:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Automatic Reactor Scram Due to Possible Adverse Weather ENS 406042004-03-23T01:31:00023 March 2004 01:31:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation Reactor Scram from 93% Power Due to Generator Trip ENS 403682003-12-02T22:58:0002 December 2003 22:58:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Scram Due to Low Reactor Water Feed Pump Suction Pressure 2023-02-01T05:43:00 | |