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On April 23, 2012, during the Braidwood St … On April 23, 2012, during the Braidwood Station Unit 1 refueling outage, it was determined that the results of planned ultrasonic (UT) examinations performed on one penetration (Penetration No. 69) did not meet the applicable acceptance criteria, requiring repair prior to returning the reactor pressure vessel head to service. A portion of the indication was conservatively assumed to be within the J-groove weld. At the time of the examination, the Braidwood Station Unit 1 reactor pressure vessel head was classified as a low susceptibility head. The cause of the recordable indication is attributed to Primary Water Stress Corrosion Cracking. The examinations were being performed to meet the requirements of 10 CFR 50.55a(g)(6)(ii)(D) and ASME Code Case N-729-1, to ensure the structural integrity of the reactor pressure vessel head pressure boundary. All of the remaining penetrations have been examined during the current refueling outage. Repairs to Penetration No. 69 were completed prior to commencing startup. No other repairs were required.</br>This is reportable pursuant to 10 CFR 50.72(b)(3)(ii)(A) since the as found indication did not meet the applicable acceptance criteria referenced in ASME Code Case N-729-1 to remain in-service without repair.</br>The NRC Resident Inspector has been notified.</br>As a result of a follow-up review, at 0600 CDT on 05/18/12, the licensee determined this was an 8 hour reportable event while Unit 1 was in Mode 4. The licensee did not determine this was a reportable event immediately after the UT was conducted on April 23, 2012. The unit is currently in Mode 3. </br>Reactor Vessel Head Penetration No. 69 is a control rod penetration. Reactor Coolant Leakage test are satisfactory and there are no indications of boron buildup on the Reactor Vessel Head. Control rod testing has not yet been performed.ol rod testing has not yet been performed. +
06:00:00, 23 April 2012 +
47,934 +
12:50:00, 18 May 2012 +
06:00:00, 23 April 2012 +
On April 23, 2012, during the Braidwood St … On April 23, 2012, during the Braidwood Station Unit 1 refueling outage, it was determined that the results of planned ultrasonic (UT) examinations performed on one penetration (Penetration No. 69) did not meet the applicable acceptance criteria, requiring repair prior to returning the reactor pressure vessel head to service. A portion of the indication was conservatively assumed to be within the J-groove weld. At the time of the examination, the Braidwood Station Unit 1 reactor pressure vessel head was classified as a low susceptibility head. The cause of the recordable indication is attributed to Primary Water Stress Corrosion Cracking. The examinations were being performed to meet the requirements of 10 CFR 50.55a(g)(6)(ii)(D) and ASME Code Case N-729-1, to ensure the structural integrity of the reactor pressure vessel head pressure boundary. All of the remaining penetrations have been examined during the current refueling outage. Repairs to Penetration No. 69 were completed prior to commencing startup. No other repairs were required.</br>This is reportable pursuant to 10 CFR 50.72(b)(3)(ii)(A) since the as found indication did not meet the applicable acceptance criteria referenced in ASME Code Case N-729-1 to remain in-service without repair.</br>The NRC Resident Inspector has been notified.</br>As a result of a follow-up review, at 0600 CDT on 05/18/12, the licensee determined this was an 8 hour reportable event while Unit 1 was in Mode 4. The licensee did not determine this was a reportable event immediately after the UT was conducted on April 23, 2012. The unit is currently in Mode 3. </br>Reactor Vessel Head Penetration No. 69 is a control rod penetration. Reactor Coolant Leakage test are satisfactory and there are no indications of boron buildup on the Reactor Vessel Head. Control rod testing has not yet been performed.ol rod testing has not yet been performed. +
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00:00:00, 18 May 2012 +
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02:04:07, 2 March 2018 +
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25.285 d (606.83 hours, 3.612 weeks, 0.831 months) +
06:00:00, 23 April 2012 +
Ultrasonic Examination Results in an Indication on the Reactor Pressure Vessel Head Penetration +
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