ENS 51861
ENS Event | |
|---|---|
12:35 Apr 11, 2016 | |
| Title | Reactor Pressure Bounday Leakage |
| Event Description | The following event description is based on information currently available. If through subsequent reviews of this event additional information is identified that is pertinent to this event or alters the information being provided at this time a follow-up notification will be made via the ENS or under the reporting requirements of 10CFR50.73.
At approximately 2335 [MST] on April 10, 2016, while performing planned routine visual examinations of Unit 1 components in the Containment Building, engineering personnel identified white residue on the piping instrument nozzle for the reactor coolant system (RCS) 2B cold leg resistance temperature detector, 1JRCET121Y. The white residue was dry and no active leakage was noted on the instrument nozzle. Preliminary chemical analysis for radionuclide and boron content of the white residue determined the existence of boron and the isotopic content was consistent with RCS fluid. At 0535 [MST] on April 11, 2016, it was determined the residue resulted from RCS pressure boundary leakage, based on results of the chemical analysis and additional examination of the piping and instrument nozzle by qualified engineering personnel. Technical Specifications Limiting Condition of Operation (LCO) 3.4.14 permits no RCS pressure boundary leakage and therefore, the discovery of leakage from the instrument nozzle represents a degradation of a principal safety barrier. This notification is being made for a degraded condition pursuant to the requirements of 10CFR 50.72(b)(3)(ii)(A). The unit has been shut down for its 19th refueling outage since 4/9/16 at 0000. The NRC resident inspectors have been informed of this condition. |
| Where | |
|---|---|
Palo Verde  Arizona (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded | |
| LER: | 05000528/LER-2016-001 |
| Time - Person (Reporting Time:+3.03 h0.126 days <br />0.018 weeks <br />0.00415 months <br />) | |
| Opened: | Kyle Rosek 15:37 Apr 11, 2016 |
| NRC Officer: | Vince Klco |
| Last Updated: | Apr 11, 2016 |
| 51861 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Cold Shutdown (0 %) |
| After | Cold Shutdown (0 %) |
WEEKMONTHYEARENS 567852023-10-09T22:07:0009 October 2023 22:07:00
[Table view]10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Reactor Coolant System Pressure Boundary Degraded ENS 523092016-10-20T01:30:00020 October 2016 01:30:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Safety Injection Piping Weld Flaw ENS 519102016-05-05T12:00:0005 May 2016 12:00:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded High Pressure Safety Injection Valve Bonnet Leakage Identified During Refueling Outage ENS 518612016-04-11T12:35:00011 April 2016 12:35:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Reactor Pressure Bounday Leakage ENS 509682015-04-08T10:30:0008 April 2015 10:30:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Reactor Coolant System Pressure Boundary Leakage Identified ENS 494162013-10-07T09:19:0007 October 2013 09:19:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Potential Reactor Coolant System Pressure Boundary Leakage Identified ENS 428862006-10-07T18:40:0007 October 2006 18:40:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Axial Indications Identified on Pressure Boundry ENS 417832005-06-17T18:00:00017 June 2005 18:00:00 10 CFR 21.21, 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Potential Degraded Condition Due to Pressurizer Heater Element Non-Conformance ENS 416292005-04-23T07:00:00023 April 2005 07:00:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Discovered Two Axial Indications on Inside Diameter of Reactor Vessel Head Penetration ENS 405562004-02-29T07:00:00029 February 2004 07:00:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Boric Acid Residue Found on Pressurizer Heater Sleeve 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 ENS 397142003-03-29T11:00:00029 March 2003 11:00:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded 2023-10-09T22:07:00 | |