ML023570253

Talking Points for Ta Briefiing on 03/14/02

ML023570253
Person / Time
Site:	Davis Besse
Issue date:	03/14/2002
From:	NRC/RGN-III
To:
References
BL-01-001
Download: ML023570253 (1)

Text

Davis-Besse Reactor Vessel Head Talking points for TA briefing on 3/14/02 Licensee was requested to respond to Bulletin 2001-01, "Circumferential Cracking of Reactor Pressure Vessel Head Penetration Nozzles," dated 8/3/01. Refueling outage originally scheduled for 3131/02, but based on discussions regarding justification for operation beyond 12/31/01, the licensee committed to a shutdown beginning on 2/16/02 along with other commitments to reduce the risk of operation until then. This was contained in a letter dated 11/30/02. Based on the information in the letter the NRC determined that there was sufficient justification for operation to continue until 2/16/02 and this was documented in a letter to the licensee, dated 12/4/01.

The licensee began their refueling outage on 2/16/02. Through the Bulletin 2001-01 inspections, they identified one potential axial through wall indication on nozzle #3 on February 27 and similar indications on both nozzle #1 and #2 on March 4. Two other nozzles, #5 and #47 also showed indications, although not through wall. The licensee reported the through wall indications to the NRC according to 10 CFR 50.72. After all 69 nozzles were inspected, the licensee initiated repair plans, which included machining the weld and nozzle material for each of the 5 nozzles.

During repair efforts on nozzle #3 on March 5, the licensee identified a void adjacent to the nozzle. Subsequent investigation of the void revealed that it is approximately 10"X8" wide and as deep as 6 1/4" through the 6 5/8" thick vessel head. For a section of approximately 4"X5", the vessel head was reduced to only the thickness of the stainless steel cladding material (3/8"). The licensee reported this condition to the NRC on 3/8102 according to 10 CFR 50.72.

The licensee initiated several teams to investigate the issue. There was a root cause team and a separate repair team established immediately. The licensee has held daily calls with the NRC to provide a status update. The licensee has 2 members of the NEI Materials Reliability Program on site to evaluate generic implications. The licensee is also performing a risk assessment of the as-found condition.

The Region had a metallurgical specialist on site at the time as part of the Bulletin follow-up inspection. The resident inspectors also followed up on the licensee's initial inspection findings. The Region Ill office initiated plans for a special inspection on March 8, 2002. These plans were changed to an Augmented Inspection Team (AIT) on March 11, after more information was available regarding the extent of damage to the reactor vessel head.

The Region issued a PN on March 8, 2002 and issued a Press Release on March 12, 2002 to announce the start of an Augmented Inspection Team (AIT). The AIT entrance was held on March 12, 2002.

The licensee sent in a commitment letter on March 12 and the Region issued a CAL on March 13.

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