ML17345B288
| ML17345B288 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 09/26/1983 |
| From: | Heltemes C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Rossin D NUCLEAR SAFETY ANALYSIS CENTER |
| Shared Package | |
| ML17345B286 | List: |
| References | |
| NUDOCS 8310060179 | |
| Download: ML17345B288 (4) | |
Text
Hr. David Rossin Director Nuclear Safety Analysis Center 3412 Hillview Avenue P.O.
Box 10412 Palo Alto, California 94303
Dear ttr. Rossin:
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 over pressure protection system were inoperable and operator actions were required to mitigate the pressure transients to prevent a more severe pressure excur sion.
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 NRC 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 repor t of our investigation is enclosed.
The purpose of this letter is to provide you with the opportunity to review the report,. particularly with regard 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 recommen-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.
Me would welcome your comments either informally by phone or fonna'lly by 0
letter.
Since we wish. to finalize and issue the report shortly, we ask
. that any comrents you may wish to make be brought to our attention within 30 days from receipt of this letter.
83i00b0i79 83092b PDR 8
SURNAMEQ DATEI ADOCK 0500025i POR Il,
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2 As you may know, AEOD reports do not represent an official NRC position or the position of the responsible t<RC 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 HRC office.
A copy of the preliminary repor t and this letter are being placed in the Public Document Room at 1717 H Street, N.W., Washington, D.C.
20555.
If you have any questions regarding this matter, please feel free to contact Wayne Lanning of my staff.
tier. Lanning can be reached at 301/492-4433.
Sincerely, jsi
Enclosure:
As stated C. J. Heltemes, Jr., Director Office for Analysis and Evaluation
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