A crack in the head would is considered a impossible accident. It would bypass every safety system in the plant. There is no question there would be a meltdown. They would quickly lose all indications of water level. This is worst than the "hole in the head" at David Besse because it is a head weld.
Something is funny with this? It doesn't seem probable all these cracks and indications would show up in one testing interval. Did they use a updated UT device? There has been a lot of NRC discussions with the accuracy of UT testing. Did the changes with these discussion lead to better UT testing. The implication are these flaws and cracks for many years, the new UT testing just showed them. What implication nationwide-how many non detected cracks and flaws are active at other plants.
The UT identified 19 indications, 9 of which are not acceptable per ASME Section XI, 2001 Edition, 2003 Addenda, Paragraph IWB-3510.
Power Reactor | Event Number: 53354 |
Facility: BRAIDWOOD Region: 3 State: IL Unit: [1] [ ] [ ] RX Type: [1] W-4-LP,[2] W-4-LP NRC Notified By: RICH ROWE HQ OPS Officer: DONG HWA PARK |
Notification Date: 04/20/2018 Notification Time: 22:22 [ET] Event Date: 04/20/2018 Event Time: 17:30 [CDT] Last Update Date: 04/20/2018 |
Emergency Class: NON EMERGENCY 10 CFR Section: 50.72(b)(3)(ii)(A) - DEGRADED CONDITION |
Person (Organization): KENNETH RIEMER (R3DO) |
Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
1 | N | N | 0 | Refueling | 0 | Refueling |
Event Text
DEGRADED REACTOR VESSEL HEAD
"On Friday, April 20, 2018 at 1730 CDT, during the Braidwood Station Unit 1 refueling outage (A1R20), a scheduled ultrasonic test (UT) was performed on the top head to upper center disc weld of the Unit 1 reactor head. The UT identified 19 indications, 9 of which are not acceptable per ASME Section XI, 2001 Edition, 2003 Addenda, Paragraph IWB-3510. "This event is reportable under 10 CFR 50.72(b)(3)(ii)(A) for 'Any event or condition that results in the condition of the nuclear power plant, including its principal safety barriers, being seriously degraded'. "The licensee notified the NRC Resident Inspector." |
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