ML19312C185
| ML19312C185 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 06/12/1975 |
| From: | DUKE POWER CO. |
| To: | |
| Shared Package | |
| ML19312C181 | List: |
| References | |
| RO-269-75-06, RO-269-75-6, NUDOCS 7912100675 | |
| Download: ML19312C185 (2) | |
Text
_
~
3,;. T :; - ' " :x. %
... q, - -
gg/Lagh_g[
DUKE POWER COMPANY OCONEE UNIT 1 Report No.:
UE-269/75-6 Repor; Date:
June 12, 1975 d
Event Date: May 14, 1975 Facility: Oconee Unit 1, Seneca, South Carolina Identification of Event: Valve operation on an incorrect unit Conditions Prior to Event: Oconee Units 1 and 2 at 100 percent full power Description of Event:
On May 14, 1975, during replacement of the Oconee Unit 2 purification demineralizer resin, the drain valve for Unit 1 purification demineralizer was inadvertently opened instead of the drain valve for Unit 2 purification demineralizer. The Control Operator immediately identified a decreasing level in the Unit 1 Letdown Storage Tank (LDST). Monitoring of various tanks and process radiation instrumentation revealed that the spent resin storage tank level was increasing.
The Unit 1 purification demineralizer drain valve was shut, and the leakage isolated.
Designation of Apparent Cause of Event:
Valves at the Oconee Nuclear Station are normally identified through the use of black identification tags.
In this instance, the valve had been labeled with a marker, which had subsequently been wetted, making it difficult to distinguish whether the valves were for Unit 1 or Unit 2.
The apparent cause of this event was failure by the operator to adequately identify the valve which he operated. The condition of the valve identifier was a contributing cause to this error.
Analysis of Event:
This incident resulted in the purification demineralizer drain valve being opened on the wrong unit, with the resultant bleed of reactor coolant letdown from the high pressure injection system. The decreasing letdown storage tank level was detected before an alarm occurred, and was promptly isolated. The resin sluice line and the spent resin storage tank were monitore' during this evolution, and no increases in radiation level were detected. Therefore, little, if any, resin had been transferred from the purification demineralizer.
lt is concluded that the health and safety of the public were not affected by this incident.
7912100 ((6-
.s
=>
s.
~
2-Corrective Action:
New identification tags for these valves have been manufactured and have been installed. The Utility Operator involved in this incident has been instructed as to the importance of ensuring that the correct valves have been identified prior to their manipulation.
4 s