ML19312C811
| ML19312C811 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 11/15/1976 |
| From: | DUKE POWER CO. |
| To: | |
| Shared Package | |
| ML19312C810 | List: |
| References | |
| RO-287-76-19, NUDOCS 8001090625 | |
| Download: ML19312C811 (1) | |
Text
,
'N
<~
DUKE POWER COMPANY OCONEE UNIT 3 Report No.: R0-287/76-19 Report Date: November 15, 1976 Occurrence Date: November 1, 1976 Facility: Oconee Unit 3, Seneca, South Carolina Identification of Occurrence: High pressure injection stop-check valves closed while reactor above 3500F Conditions Prior to Occurrence: Unit in heatup Description of Occurrence:
On November 1, 1976, during cooldown of the reactor coolant system for repair of valve 3RC-1, the high pressure injection system stop-check valves in the "B" train, 3HP-152 and 3HP-153,were discovered closed.
This candition had existed for a period of eleven and one-half hours during which the "B" HPI train was required to be operable by Oconee Technical Specification 3.3.2.
Upon discovery valves 3HP-152 and 153 were prouptly opened.
Designation of Apparent Cause of Occurrence:
Following any major shutdown and prior to establishing seal flow to the HPI pumps and reactor heatup, an examination of the valves associated with the HPI system is made. Utilizing a checklist, this procedure verifies that the components of each train are in correct position.
On October 27, 1976, prior to heatup following the Unit 3 refueling outage, valves 3HP-152 and 153 were inspected pursuant to this procedure and initialed as being open.
There is no evidence that indicates that these valves were repositioned after this inspection. Therefore this incident has been attributed to a personnel error in ascertaining the proper valve position during this initial inspection.
Analysis of Occurrence:
The mispositioned valves were discovered prior to criticality and returned to the correct position.
It is considered that since the reactor was sub-critical during this period, the reactor coolant temperature and pressure conditions were below the normal operating conditions, and due to the short period of time this~ condition existed, the probability of an incident re-j quiring the HPI system was exceedingly remote.
However, if the HPI system had been required, the redundant HPI train was operable and has full capa-bility of performing the ES ' function of the system.
It is, therefore, concluded that the health and safety of the public was not adversely affected by this incident.
Corrective Action:
Upon discovery,' the valves in question were promptly placed in the correct ES position, and the HPI checklist was completely rerun to assure that no further j
discrepancies existed. This incident and methods for determining valve posi-tions were also reviewed with all personnel.
It is felt that no further cor-rective action is necessary.
700/03oM5
_