PNO-V-93-016, on 930828,plant Restarted After Refueling Outage That Proceeded Tube Rupture Event on 930314.Cause of Tube Rupture Was Due to Intergranular Attack.Unit 3 Operating at 100% Power
| ML20149D533 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 08/30/1993 |
| From: | Kirsch D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | |
| References | |
| PNO-V-93-016, PNO-V-93-16, NUDOCS 9309210060 | |
| Download: ML20149D533 (1) | |
ij August 30, 1993 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-V-93-016 This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by the Region V staff on this date.
Facility Licensee Emeraency Classification Arizona Public Service Co.
Notification of Unusual Event Palo Verde 2 Alert Wintersburg, Arizona Site Area Emergency Dockets: 50-529 General Emergency X Not Applicable
Subject:
PLANT RESTART AFTER REFUELING OUTAGE At 1:15 a.m.
(MST) on August 28, 1993, Palo Verde Unit 2 entered Mode 2 after the fourth refueling outage.
The outage, which commenced on March 19, 1993, was proceeded by a tube rupture event in the Number 2 steam generator on March 14.
During the outage, the licensee conducted i
extensive eddy current inspections of the Steam Generator tubes which resulted in plugging 74 and 175 tubes in steam generators 1 and 2 7 respectively.
The licensee concluded that the cause of the tube rupture was due to intergranular attack and stress corrosion cracking, probably stimulated by deposited chemicals and possibly assisted by the j
introduction of demineralizer resin into the steam generator.
]
A Confirmatory Action Letter (CAL), issued by the NRC to the licensee on June 4, 1993, was lifted in an NRC letter dated August 19, 1993.
The CAL confirmed commitments made by the licensee with respect to the tube rupture and investigation into the cause of the event.
Unit 2 will operate for six months and then be shut down for a mid-cycle steam generator eddy current inspection.
Palo Verde Unit 1 is operating at 65% power and is coasting down to begin a refueling outage on September 4, 1993.
Unit 3 is operating at 100%
power.
This information is current as of 9:00 a.m.
(PDT) August 27, 1993.
Contact:
Dennis Kirsch (510)975-0290 1
200040 ll0 9309210060 93083O['
][h PDR I&E PNO-V-93-016 PDR_
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