ENS 40684
ENS Event | |
|---|---|
22:30 Apr 18, 2004 | |
| Title | Residual Heat Removal System Isolation Due to a Rise in Reactor Pressure |
| Event Description | At 1830 hours0.0212 days <br />0.508 hours <br />0.00303 weeks <br />6.96315e-4 months <br /> on 18 April 2004, Nine Mile Point Unit 2 was restoring from reactor pressure vessel leakage test.
Reactor pressure was ~82 psi, temperature ~178 degrees, reactor level was solid with both reactor recirculation pumps running in slow speed per the leak test procedure. 'B' residual heat removal system was being warmed up in preparation for going in to service. Reactor water cleanup reject from the vessel was secured to maintain RPV [Reactor Pressure Vessel] pressure stable in order to provide driving head for flow through the residual heat removal discharge line to radwaste. The line is warmed up from the reactor, back through the Shutdown cooling isolation valve, to radwaste prior to placing shutdown cooling in service. When warm-up criteria are met, the operating procedure directs securing flow. When flow was secured, this effectively isolated the solid reactor vessel, resulting in a rise in reactor pressure. Pressure peaked at ~146 psi before operators established reactor water cleanup reject flow. When RPV pressure reached 128 psi, the residual heat removal system isolation was automatically initiated as designed. The shutdown cooling injection valve, which was open to support piping warm-up, closed as designed. All other shutdown cooling valves were closed prior to the event per the warm-up lineup. RPV is currently depressurized with shutdown cooling in service. All systems are functioning as expected. The licensee notified the NRC Resident Inspector.
The following is a retraction of ENS Notification #40684: On April 18, 2004, Nine Mile Point Unit 2 reported Residual Heat Removal Shutdown Cooling System isolated due to a pressure spike while warming up the piping. The shutdown cooling injection valve, which was open to support piping warm-up, closed as designed. All other shutdown cooling valves were closed prior to the event per the warm-up lineup. Accordingly, Control Room personnel conservatively initiated ENS reporting under 10CFR50.72(b)(3)(iv)(A) in response to the valid containment isolation signal. Subsequent analysis has concluded that, although the isolation signal was valid, it was not a general containment isolation signal (i.e., the isolation signal only involved the shutdown cooling system) and the shutdown cooling function of the Residual Heat Removal System is not listed under 10CFR50.72(b)(3)(iv)(B) as a system that is required to be reportable. This system isolation does not meet the reporting requirements of 10CFR50.72(b)(3)(iv)(A). Therefore, this notification made on April 18, 2004, is being retracted. The NRC Resident Inspector was notified. NRC R1DO (Ron Bellamy) notified. |
| Where | |
|---|---|
Nine Mile Point  New York (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
| Time - Person (Reporting Time:+1.25 h0.0521 days <br />0.00744 weeks <br />0.00171 months <br />) | |
| Opened: | David Richardson 23:45 Apr 18, 2004 |
| NRC Officer: | Arlon Costa |
| Last Updated: | Jun 1, 2004 |
| 40684 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Cold Shutdown (0 %) |
| After | Cold Shutdown (0 %) |
WEEKMONTHYEARENS 573342024-09-23T11:20:00023 September 2024 11:20:00
[Table view]10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Automatic Reactor Scram Due Turbine Trip ENS 570042024-03-04T00:42:0004 March 2024 00:42:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram Due to Main Turbine Trip on LOW Condenser Vacuum ENS 567102023-09-02T10:32:0002 September 2023 10:32:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Automatic Reactor Scram Due to Feedwater Transient ENS 560892022-09-04T20:39:0004 September 2022 20:39:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Specified System Activation ENS 558212022-04-05T06:23:0005 April 2022 06:23:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge Scram on LOW Level ENS 540352019-04-29T20:33:00029 April 2019 20:33:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Scram Due to Power Oscillations and High Pressure Coolant Injection System Initiation ENS 539982019-04-14T04:03:00014 April 2019 04:03:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram and Specified System Actuation ENS 533952018-05-10T06:48:00010 May 2018 06:48:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Valid Emergency Diesel Start on Partial Loss of Offsite Power ENS 529502017-09-06T15:57:0006 September 2017 15:57:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram on Low Reactor Vessel Water Level ENS 524252016-12-10T13:48:00010 December 2016 13:48:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Scram Due to High Main Turbine Vibrations ENS 513692015-09-04T13:16:0004 September 2015 13:16:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unplanned Automatic Scram and Specified System Actuations Due to Msiv Closure ENS 498322014-02-16T17:16:00016 February 2014 17:16:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Unit 2 Experienced a Partial Loss of Offsite Power with Autostart of Division I and III Edgs ENS 485902012-12-13T21:30:00013 December 2012 21:30:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification Required Shutdown Due to Primary Containment System Declared Inoperable ENS 484812012-11-06T05:06:0006 November 2012 05:06:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation High Pressure Coolant Injection Actuation Signal ENS 484772012-11-03T12:23:0003 November 2012 12:23:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Scram on Low Reactor Water Level ENS 484562012-10-30T01:00:00030 October 2012 01:00:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Initiation of Emergency Diesel Generator Due to Loss of One Off-Site Power Source ENS 484532012-10-29T04:00:00029 October 2012 04:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Rps Actuation While Critical Due to Generator Load Reject ENS 483232012-09-20T13:23:00020 September 2012 13:23:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Scram and High Pressure Coolant Injection System Initiation ENS 481102012-07-17T15:18:00017 July 2012 15:18:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram Due to High Neutron Flux ENS 468082011-05-03T00:51:0003 May 2011 00:51:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Reactor Scram ENS 464092010-11-10T15:56:00010 November 2010 15:56:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unplanned Automatic Scram and High Pressure Coolant Injection System Initiation During Testing ENS 454122009-10-05T15:58:0005 October 2009 15:58:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Scram and High Pressure Coolant Injection Following a Loss of Feedwater Level Control ENS 449822009-04-10T09:38:00010 April 2009 09:38:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation High Pressure Coolant Injection Automatic Initiation Due to Turbine Trip ENS 449232009-03-21T05:21:00021 March 2009 05:21:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation High Pressure Coolant Injection System Initiation Following Planned Manual Scram ENS 445982008-10-24T01:26:00024 October 2008 01:26:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Manual Reactor Scram Due to Loss of the Electronic Pressure Regulator ENS 442062008-05-13T12:25:00013 May 2008 12:25:00 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unusual Event Declared Due to Loss of Offsite Power ENS 426332006-06-12T17:02:00012 June 2006 17:02:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Hpci Inititation Signal Due to Turbine Trip Signal During Startup ENS 419272005-08-18T13:49:00018 August 2005 13:49:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Automatic Scram Due to Loss of a Power Board ENS 415842005-04-10T10:00:00010 April 2005 10:00:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Scram Signal Resulting from Failure of a Supply Valve to the Scram Air Header ENS 409982004-08-30T12:35:00030 August 2004 12:35:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unit 1 Manually Scrammed Due to Oscillating Reactor Vessel Water Level ENS 407192004-05-02T06:17:0002 May 2004 06:17:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Manual Scram Due to Rising Torus Temperature Due to Stuck Open Erv ENS 406842004-04-18T22:30:00018 April 2004 22:30:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Residual Heat Removal System Isolation Due to a Rise in Reactor Pressure ENS 403222003-11-14T02:49:00014 November 2003 02:49:00 10 CFR 50.72(b)(3)(iv)(A), System Actuation Loss of 115 Kv Line Results in Emergency Diesel Generator Auto-Start 2024-09-23T11:20:00 | |