ML20064F899
| ML20064F899 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 11/03/1978 |
| From: | TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML20064F898 | List: |
| References | |
| NUDOCS 7812050270 | |
| Download: ML20064F899 (1) | |
Text
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y ENCLOSURE SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 SEISMICALLY QUALIFIED PATH FOR MAKEUP TO SPENT FUEL STORACE FACILITY NOT PROVIDED NCR MEB 1010 FINAL REPORT j
Description of Deficiency In contradiction to TVA commitments in the response to Sequoyah Nuclear Plant (SNP) Final Safety Analysis Report (FSAR) Question 9.31, a permanent Seismic Category I makeup piping system from the refueling water storage tank (RWST) to the spent fuel storage pool was not provided.
Safety Implications Had the deficiency gone uncorrected, the safety of the plant could have been affected only if a large loss of inventory from the spent fuel pool occurred with a simultaneous loss of the required portions of all presently available makeup water sources.
These sources include the demineralized water system, the primary makeup water system, and the fire protection system. The response to SNP FSAR Question 9.12 contains more information concerning the qualifi-i cation of these water systems. Ilowever, regardless of the availability of makeup water, design provisions prevent large inventory loss from the spent fuel pool.
The pool is a Seismic Category I structure with a stainless steel liner.
If rupture of the liner occurs, a low-level alarm is annunciated in the main control room when the water level drops two inches below normal ninimum pool level.
Plug valves are installed in the pool leak chase system drains which may be used to terminate flow f rom the pool as a result of leakage. The pool cooling system is fully qualified and redundant. Therefore, inventory loss because of pool cooling system failure (with consequential pool heatup) is not considered possible.
Evaporation loss is not significant.
Based on this information, it is highly unlikely this deficiency would have adversely affected the safe eperation of the plant.
Correction Actior.
In order to comply with TVA commitments, a qualified ifne and necessary valves will be installed from the common discharge of the refueling water purification pumps (RWPP) to the seismically qualified spent fuel poel cooling loop.
All piping, valves, and pumps from the RWST to the common discharge of the RUPP will be seismically qualified. This corrective action will be completed before plant operation.
I 781205o 2.7 o
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