Event Notification Report for September 14, 2002
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
09/13/2002 - 09/14/2002
EVENT NUMBERS
39191
Power Reactor
Event Number: 39191
Facility: NORTH ANNA
Region: 2 State: VA
Unit: [] [2] []
RX Type: [1] W-3-LP,[2] W-3-LP
NRC Notified By: JOHNSTONE
HQ OPS Officer: JOHN MacKINNON
Region: 2 State: VA
Unit: [] [2] []
RX Type: [1] W-3-LP,[2] W-3-LP
NRC Notified By: JOHNSTONE
HQ OPS Officer: JOHN MacKINNON
Notification Date: 09/14/2002
Notification Time: 22:14 [ET]
Event Date: 09/14/2002
Event Time: 20:12 [EDT]
Last Update Date: 10/07/2002
Notification Time: 22:14 [ET]
Event Date: 09/14/2002
Event Time: 20:12 [EDT]
Last Update Date: 10/07/2002
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(A) - DEGRADED CONDITION
10 CFR Section:
50.72(b)(3)(ii)(A) - DEGRADED CONDITION
Person (Organization):
MIKE ERNSTES (R2)
WILLIAM DEAN (NRR)
MIKE ERNSTES (R2)
WILLIAM DEAN (NRR)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | N | 0 | Refueling | 0 | Refueling |
BORIC ACID RESIDUE DISCOVERED DURING A BARE HEAD INSPECTION OF THE REACTOR VESSEL HEAD
Two reactor vessel head penetrations on Unit 2 ( #21 and # 31) appear to have exhibited some amount of leakage during the past cycle of operation. This conclusion is based on the boric acid residue found at these locations during the bare head inspection. This is a preliminary finding, further NDE and Liquid Penetrant Inspections will be performed and a repair plan will be developed during this outage.
A inspection of the reactor vessel head was performed last year and no boric acid residue was noted.
The NRC Resident Inspector will be notified of this event by the licensee.
* * * UPDATE ON 10/07/02 @ 1647 FROM JOHNSTONE TO GOULD * * *
Preliminary results obtained during the fall refueling outage are as follows:
A bare head visual inspection resulted in the identification of two penetrations that appeared to have exhibited some amount of leakage (penetrations 21 and 31 as previously reported), four additional penetrations are suspected of leaking, and several penetrations are masked with boric acid residue (due to a conoseal leak) that made their status indeterminate. Inspection of 59 J-groove welds with eddy current (ET) was performed. The ET inspections identified at least one indication of greater than 6 mm in length in about 83% of the J-groove welds. Additionally six J-groove welds, on thermocouple locations that could not be interrogated by ET, were examined by liquid penetrant test (PT) and found to have rejectable (greater than 1/16'" linear) indications. Three of the penetrations with indications discovered by PT had been previously repaired with an embedded flaw technique that now is believed to have been improperly executed. All penetrations exhibiting leakage and suspected of leakage based on the bare head visual inspection had ET indications> 6 mm in length or rejectable PT indications. One of the suspected leaking penetrations was one of three previously repaired.
Thirty five penetration inspections from the tube ID utilizing an open housing ET and ultrasonic inspection (UT) probe have been conducted. Numerous axial and circumferential ID and OD indications have been found. Most of the OD indications lie in the penetration tube between the toe and the root of the J-groove weld. About 20% of the penetrations have tube OD circumferential "crack like" indications. All are located between the root and the penetration side toe of the J-groove weld. Penetration (54) has two OD circumferential tube indications, the most limiting being about 80 degrees and .226 inches deep (tube wall .62 inches). This penetration had no leakage. Penetration 54 is bounding for the inspections completed.
A boat sample from one suspected leaking penetration was obtained and sent to a vendor lab for analysis.
The NRC Resident Inspector will be notified.
Two reactor vessel head penetrations on Unit 2 ( #21 and # 31) appear to have exhibited some amount of leakage during the past cycle of operation. This conclusion is based on the boric acid residue found at these locations during the bare head inspection. This is a preliminary finding, further NDE and Liquid Penetrant Inspections will be performed and a repair plan will be developed during this outage.
A inspection of the reactor vessel head was performed last year and no boric acid residue was noted.
The NRC Resident Inspector will be notified of this event by the licensee.
* * * UPDATE ON 10/07/02 @ 1647 FROM JOHNSTONE TO GOULD * * *
Preliminary results obtained during the fall refueling outage are as follows:
A bare head visual inspection resulted in the identification of two penetrations that appeared to have exhibited some amount of leakage (penetrations 21 and 31 as previously reported), four additional penetrations are suspected of leaking, and several penetrations are masked with boric acid residue (due to a conoseal leak) that made their status indeterminate. Inspection of 59 J-groove welds with eddy current (ET) was performed. The ET inspections identified at least one indication of greater than 6 mm in length in about 83% of the J-groove welds. Additionally six J-groove welds, on thermocouple locations that could not be interrogated by ET, were examined by liquid penetrant test (PT) and found to have rejectable (greater than 1/16'" linear) indications. Three of the penetrations with indications discovered by PT had been previously repaired with an embedded flaw technique that now is believed to have been improperly executed. All penetrations exhibiting leakage and suspected of leakage based on the bare head visual inspection had ET indications> 6 mm in length or rejectable PT indications. One of the suspected leaking penetrations was one of three previously repaired.
Thirty five penetration inspections from the tube ID utilizing an open housing ET and ultrasonic inspection (UT) probe have been conducted. Numerous axial and circumferential ID and OD indications have been found. Most of the OD indications lie in the penetration tube between the toe and the root of the J-groove weld. About 20% of the penetrations have tube OD circumferential "crack like" indications. All are located between the root and the penetration side toe of the J-groove weld. Penetration (54) has two OD circumferential tube indications, the most limiting being about 80 degrees and .226 inches deep (tube wall .62 inches). This penetration had no leakage. Penetration 54 is bounding for the inspections completed.
A boat sample from one suspected leaking penetration was obtained and sent to a vendor lab for analysis.
The NRC Resident Inspector will be notified.