ENS 50509
ENS Event | |
|---|---|
18:08 Oct 4, 2014 | |
| Title | Containment Leak Rate Exceeds Acceptance Criteria |
| Event Description | The total as-found Minimum Pathway Leakage Rate for the Primary Containment exceeded Level 1 acceptance criteria. Acceptance criteria of 321 (Standard Liters per Minute) SLM was not met. This criteria is equivalent to 1.0 La, the maximum allowable Primary Containment Leakage rate as prescribed by Technical Specification 5.5.6.c.1.
This is reportable under 10CFR50.72(b)(3)(ii)(A) as 'The condition of the nuclear power plant, including its principal safety barriers, being seriously degraded .. ' All other Level 1 acceptance criteria were met. All as-left containment leakage requirements for startup have been met. The licensee will notify the NRC Resident Inspector.
On October 4, 2014, FitzPatrick reported that the total as-found containment minimum pathway leak rate exceeded the maximum allowable containment leak rate per the containment leakage rate testing program. This was primarily due to the drywell exhaust Penetration X26A/B. Penetration X26A/B Local Leak Rate Testing (LLRT) results were initially indeterminate, and therefore conservatively assumed to exceed the primary containment leakage acceptance criteria. The excessive leakage was assumed for Penetration X26A/B due to LLRT results for two (2) containment isolation valves (CIV). The subject CIVs are installed in series on Penetration X26A/B. The upstream valve is not isolable from primary containment, therefore, LLRT testing for these two CIVs is performed simultaneously via pressurization through a test connection between the two valves. During the LLRT, Penetration X26A/B was pressurized to 44.42 psig. The required test pressure for this penetration is 45.3 psig. As the required test pressure was not achieved, the LLRT results were initially indeterminate. Excessive leakage was conservatively assigned to the penetration resulting in the failure of the primary containment leakage acceptance criteria. This condition (failure of the primary containment leakage acceptance criteria) was determined to be reportable pursuant to 10 CFR 50.72(b)(3)(ii)(A) as a condition of the nuclear power plant, including its principle safety barriers, being seriously degraded. A subsequent engineering evaluation addressed the leakage for Penetration X26A/B, and concluded that the LLRT test results did not reflect failure of the primary containment leakage acceptance criteria. The installed configuration prevents testing these valves individually; however, troubleshooting activities indicated no detectable leakage through the downstream valve. The upstream valve was removed and inspected. The results of the inspection confirmed that all LLRT leakage was attributable to the upstream valve. Following maintenance activities, the valve was reinstalled and Penetration X26A/B was retested. The post-maintenance LLRT resulted in a total leakage of 0.078 SLM for Penetration X26A/B. The resultant total primary containment leakage rate determined on a minimum pathway basis was below the operability limits of 192 and 321 SLM (0.6 La and 1.0 La, respectively). Primary containment remained operable throughout Cycle 21; no degraded condition existed. Therefore, this [event notification] is being retracted. The licensee has notified the NRC Resident Inspector. Notified R1DO (Dentel) |
| Where | |
|---|---|
FitzPatrick  New York (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded | |
| Time - Person (Reporting Time:+3.9 h0.163 days <br />0.0232 weeks <br />0.00534 months <br />) | |
| Opened: | David Richardson 22:02 Oct 4, 2014 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Dec 2, 2014 |
| 50509 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Cold Shutdown (0 %) |
| After | Cold Shutdown (0 %) |
WEEKMONTHYEARENS 525032017-01-22T19:00:00022 January 2017 19:00:00
[Table view]10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Weld Defect Found During a Shutdown Inspection ENS 524902017-01-14T11:13:00014 January 2017 11:13:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Degraded Condition Due to Through-Wall Leak ENS 505092014-10-04T18:08:0004 October 2014 18:08:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Containment Leak Rate Exceeds Acceptance Criteria ENS 445162008-09-23T19:00:00023 September 2008 19:00:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Degraded Condition Due to Recirc Nozzle Weld Axial Crack ENS 425492006-05-04T02:30:0004 May 2006 02:30:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Rcic Declared Inoperable Due to Degraded Flow Instrument ENS 418152005-06-30T23:29:00030 June 2005 23:29:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown, 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Primary Containment Inoperable Due to Small Crack in Torus 2017-01-22T19:00:00 | |