ENS 44274
ENS Event | |
|---|---|
06:56 Jun 6, 2008 | |
| Title | Tech Spec Required Shutdown Due to Leak in Safety Injection Tank Vent Line |
| Event Description | On Thursday June 5, 2008 at 2356 MST Palo Verde Nuclear Station Unit 1 initiated a normal reactor shutdown to comply with condition C of Technical Specification (TS) LCO 3.5.1 and to facilitate a weld repair on a nitrogen leak found on the Safety Injection Tank (SIT) 1A vent line.
LCO 3.5.1 requires that all four SITs be operable in Modes 1 and 2. On June 5, 2008, at 0225 hours0.0026 days <br />0.0625 hours <br />3.720238e-4 weeks <br />8.56125e-5 months <br /> MST, Unit 1 entered Condition B which provides allowance for one SIT to be inoperable for a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period. The SIT will not be restored to operable status within the TS required 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period, therefore, Condition C will be applicable at 0225 MST on June 6 2008. Condition C requires shutdown to Mode 3 in six hours and to reduce pressurizer pressure to less than 1837 psia within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. On June 06 at 0148 hours0.00171 days <br />0.0411 hours <br />2.44709e-4 weeks <br />5.6314e-5 months <br /> MST, Unit 1 was manually tripped from approximately 20% power. The shutdown did not result in a release of radioactivity to the environment and did not adversely affect the safe operation of the plant or health and safety of the public. The primary plant is being stabilized in Mode 3 in forced circulation with both steam generators used for heat removal. Unit 1 is stable at normal operating temperature and pressure in Mode 3. S/G's are being feed via main feed. All other safety related systems are operable. Decay heat is via SBC system to the condenser. There is no impact on the other units. The licensee notified the NRC Resident Inspector. |
| Where | |
|---|---|
Palo Verde  Arizona (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown | |
| LER: | 05000528/LER-2008-003 |
| Time - Person (Reporting Time:+-1.27 h-0.0529 days <br />-0.00756 weeks <br />-0.00174 months <br />) | |
| Opened: | Brian Ferguson 05:40 Jun 6, 2008 |
| NRC Officer: | Joe O'Hara |
| Last Updated: | Jun 6, 2008 |
| 44274 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | Yes, Manual Scram |
| Before | Power Operation (100 %) |
| After | Hot Standby (0 %) |
WEEKMONTHYEARENS 506002014-11-06T18:16:0006 November 2014 18:16:00
[Table view]10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification Required Shutdown Due to Dropped Control Element Assembly ENS 496012013-12-03T06:24:0003 December 2013 06:24:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Tech Spec Required Shutdown Due to Dropped Control Element Assembly ENS 442742008-06-06T06:56:0006 June 2008 06:56:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Tech Spec Required Shutdown Due to Leak in Safety Injection Tank Vent Line ENS 438042007-11-24T05:26:00024 November 2007 05:26:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification Required Plant Shutdown Due to Inoperable Load Sequencer ENS 437362007-10-22T10:11:00022 October 2007 10:11:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Shutdown Due to Inoperable Steam Driven Auxiliary Feedwater Pump ENS 431732007-02-19T21:57:00019 February 2007 21:57:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Unit 2 Performed a Ts Required Shutdown ENS 428472006-09-19T08:05:00019 September 2006 08:05:00 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Pressurizer Heater Capacity Less than Tech Spec Limit ENS 424872006-04-10T19:33:00010 April 2006 19:33:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Unit 2 Entered a Ts Required Shutdown Due to Inoperable Auxiliary Feedwater Pumps ENS 420502005-10-11T23:02:00011 October 2005 23:02:00 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, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Tech Spec Required Shutdown of Both Unit 2 and 3 ENS 419392005-08-22T23:05:00022 August 2005 23:05:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification Shutdown Due to Core Protection Calculator System (Cpcs) Software Not Consistent with System Design Requirements. ENS 419132005-08-12T07:19:00012 August 2005 07:19:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Plant Entered Lco Action Statement 3.8.1 to Be in Mode 5 Due to Unit 1 "B" Diesel Gen. Being Declared Inoperable ENS 415022005-03-18T22:00:00018 March 2005 22:00:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specification Required Shutdown Due to Inoperable Diesel Generator ENS 413892005-02-09T08:04:0009 February 2005 08:04:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown Technical Specifications Required Shutdown Due to Loss of Normal and Alternate Power to Safety Bus ENS 405032004-02-03T22:35:0003 February 2004 22:35:00 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown, 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Technical Specification Required Shutdown Due to Rcs Pressure Boundary Leakage 2014-11-06T18:16:00 | |