ML19317D752
| ML19317D752 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 03/25/1977 |
| From: | DUKE POWER CO. |
| To: | |
| Shared Package | |
| ML19317D749 | List: |
| References | |
| RO-269-77-05, RO-269-77-5, NUDOCS 7912100518 | |
| Download: ML19317D752 (2) | |
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DUKE POWER COMPAhT 000 NEE UNIT 1 4p Report No.: R0-269/77-5 Report Date: March 25, 1977 Occurrence Date: February 23, 1977 Facility: Oconee Unit 1, Seneca, South Carolina Identification of Occurrence: Reactor protective system setpoint not recali-brated promptly after technical specification change Conditions Prior to Occurrence: Unit at 100 percent full power Description of Occurrence:
On February 4, 1977, the NRC approved amendment No. 37 for Facility Operating License DPR-38. The amendment, which increased the flux / flow trip setpoint in the Oconee Technical Specifications from 1.055 to 1.07 by eliminating the reactor internals vent valve flow penalty, was effective on the day of issu-ance.
On February 23, 1977, during review of the amendment, it was determined that although the new " Protection System Maximum Allowable Setpoints" curve generally provided more operating flexibility in comparison with the previous limits on flux - imbalance - flow, a small portion of the amended curve was more< conservative than the former technical specification limit.
New RPS calibration data was calculated and approved by February 25, 1977.
Recali-bration of the RPS was completed on March 3, 1977.
Therefore, the RPS flux /
flow trip setpoints for the Oconee Unit 1 RPS was less conservative than specified in Technical Specification 2.3, as amended by amendment No. 37, for approximately 27 days.
Apparent Cause of Occurrence:
The incident was caused by delays incurred between issuance of an amendment and implementation of the amendment, due to the length of time necessary to formally receive, distribute and implement certain types of technical speci-fication changes.
Analysis of Occurrence:
Amendment No. 37 to Facility Operating License DPR-38 increased the flux /
flow trip setpoint of the Reactor Protective System from 1.055 to 1.07.
The operating curve generated utilizing the former setpoint of 1.055 was therefore predominantly more conservative than the amended operating curve.
Reactor operational safety limits were not adversely affected by this incident. It is concluded that the health and safety of the public were not affected.
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Corrective Action:
The PfS was recalibrated to reflect the amended flux / flow trip setpoint by March 3, 1977. To prevent recurrence of this incident, the method of handling technical specification changes has been reviewed and a recommendation has been made to the NRC by letter dated March T's,1977 to establish a formal policy on the issuance of technical specification changes which will allow time for proper implementation of the changes.
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