ML19345D820
| ML19345D820 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 11/05/1980 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19345D819 | List: |
| References | |
| NUDOCS 8012170477 | |
| Download: ML19345D820 (1) | |
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A UNITED STATES NUCLEAR REGULATORY COMMISSION y
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QMW,)aj SAFETY EVALUATION REPORT INADVERTENT SAFETY INJECTION DURING COOLCOW!(
DIVISI0N OF LICEN_ SING Inadvertent actuation of the emergency core cooling sys:em (ECCS) had occurre:!
ct a number of PWR facilities.
If, at the time of inadvertpt actuation, the reactor coolant system (RCS) pressure is less than the EC'.S discharge pressure and the RCS temperature is significantly above the ECCS watar temperature, than the regions of the injection nozzles can be subjected to ther.nal stresses.
We have performed analyses using conservative assurdticas to obtain an upoer
- bound for these stresses and conclude that a typical ne::le could withstanc at least fifty (50) injection events with the temperatt.re cifferential as high as about 500'F.
These results are consistent with these reporced by Wes -
inghouse on the Salem docket.
It is likely that a facility could withstand more than 50 inadvertent actuations of the ECCS because I) not all inadverte t actuations will result in cold water injection inte a ro:.ECS, 2) if inje::ica i
does occur, the temperature differential will nest likely te less than that assumed in our analyses, and 3) there is additional margin to failure because the ASME Code limit is itself conservative.
IE Circular 78-05 dated May 23, 1978 on this subject advised facility cwrers of soecific actions that could be taken mi.nimizing the fre:uency of inadvertant safety injections.
We conclude that no additional licensi.g a: tion is recci ed at this time.
It would be prudent, however, for facility :wners to cen:inus to monitor the frecuency of these events.
If a partic:1cr F4R facility sh=uid experience more than acout 25 inadvertent safety injections, taen a plan s,a:ific analysis should be considered.
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