ML19257B256
| ML19257B256 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 01/07/1980 |
| From: | Tierney F NORTHERN STATES POWER CO. |
| To: | |
| References | |
| NUDOCS 8001150420 | |
| Download: ML19257B256 (1) | |
Text
Ni3D NORTHERN STATES POWER COMPANY PRAIRIE ISLAND NUCLEAR GENE'PATING PLANT RR #2 Welch,. TIN 55089 January 7, 1980 Mr. James G. Keppler, Director Region III Of fice of Inspection and Enforcement US Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137 Attention:
R. F. Warnick Reportable Occurrence No. 80-1 At 0600 hours0.00694 days <br />0.167 hours <br />9.920635e-4 weeks <br />2.283e-4 months <br /> on January 6,1980, with. Unit 1 at 100% power, both trains of caustic addition (to the containment spray system) were found valved out.
The valves were 1::raediately reopened.
Preliminary investigation shows the valves were closed aistakenly at about 2330 hours0.027 days <br />0.647 hours <br />0.00385 weeks <br />8.86565e-4 months <br /> on January 3rd, during Unit 2 cooldown for refueling. The containment spray system itself was operable throughout the period.
The analysis in the Prairie Island Final Safety Analysis Report Section 6.4. 3 shows that caustic addition is not needed to prevent stress corrosion crack-ing in systems wetted by boric acid solutions. Also, the containment spray system (with caustic addition) is said to be effective in scrubbing fission products from the post-accident containment atmosphere; but no credit is taken for this scrubbing action in the analysis of the design basis accident. Ilence,
it is felt that the risk to the health and safety of the public was minimal.
An investigation of the occurrence is continuing.
Sincerely, F. P. Tierney, Jr.
Plant Manager Prairie Island Nuclear Plant FPT/jd cc: L
- 0. Mayer Director, MIPC (2) c/o Distribution Services Branch, DDC, ADM jJgg }j}
C. D. Feierabend 8
0 SI t Nd f
8001150