ML17345B291
| ML17345B291 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 09/26/1983 |
| From: | Heltemes C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | John Marshall ARKANSAS POWER & LIGHT CO. |
| Shared Package | |
| ML17345B286 | List: |
| References | |
| NUDOCS 8310060194 | |
| Download: ML17345B291 (4) | |
Text
SKP 26 Arkansas Power and Light Company ATTN:
John Marshall, t1anager Licensing P.O.
Box 551 Little Rock, Arkansas 72203 Gentlemen:
Subject:
Case Study Report - Low Temperature Overpressure Events At Turkey Point Unit 4 On November 28 and 29, 1981 during the filling and venting process while restarting the reactor after a refueling outage, two overpressure events occurred at Turkey Point Unit 4 which exceeded by a factor of two the technical specification limits.
Both trains of the overpressure protection system were inoperable and operator actions were required to mitigate the pressure transients to prevent a more severe pressure excursion.
The safety significance of the events is the possibility of the reactor vessel failure by brittle fracture as a consequence of the overpressure transients during low temperature operation.
These overpressurization transients were the first events to occur at an operating pressurized water reactor which exceeded the technical specification limits since the WRC staff resolved the generic issue of low temperature overpressure transients in 1979.
The events were identified to Congress as Abnormal Occurrences which indicate that the events involved a major reduction in the degree of protection to the public health and safety.
Because of the safety significance of the
- events, AEOD performed a detailed case study of the event sequences, the causes and the corrective actions taken, and the generic implications of the events.
A preliminary report of our investigation is.enclosed.
The purpose of this letter is to provide you with the opportunity to review the report, particularly with regar d to its completeness and accuracy, prior to the issuance of the AEOD final report.
Changes to the findings, con-clusions and recommendations will be considered only if the underlying information concerning the details of plant design, systems operation or event sequence is in error.
Therefore, comments are being solicited on the technical accuracy of the report.
The findings, conclusions, and recommenso dations are provided for your information in order that you understand the significance AEOD places on this event and therefore obtain a more complete picture of the total report.
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You will note that the filling and venting method at Arkansas Nuclear One is described as an exemplary"practice which excludes water solid operation.
The report suggests that the details of the procedure be provided to other operating PWRs in cooperation with the Institute For Nuclear Power Operation.
We would appreciate specific comments on the accuracy of the filling and venting operation and whether the suggestion for transferring the technology to other plants may be acceptable to you.
As you may know, AEOD reports do not represent an official HRC position or the position of the responsible HRC program office.
Our reports are one input to an ongoing review and evaluation process, and any recommendation contained in our final report will be considered and perhaps modified or eliminated by the responsible NRC office.
A copy of the preliminary report and this letter are being placed in the Public Document Room at 1717 H Street, H.W., Washington, D.C.
20555.
If you have any questions regarding this matter, please feel free to contact Wayne Lanning of my staff.
Hr. Lanning can be reached at 301/492-4433.
Sincerely,
Enclosure:
As stated C. J. Heltemes, Jr'., Director Office for Analysis and Evaluation
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