Influence of materials interactions on Post-Accident Heat Removal containment transients

This paper has discussed calculations of the containment transients associated with a hypothetical reactor vessel melt-through incident. The calculations have emphasized the potential for release of large quantities of water from containment structural concrete. Test data on rate of release from thick wall steel lined concrete structures would be useful. Hydrogen generation in quantities sufficient to reach flammability limits in a containment building appears possible. However, there are reasons to believe hydrogen would not accumulate until the building became self-inerted by consumption of the oxygen originally present. Hydrogen-oxygen recombination would introduce additional heat into the RCB. Experimental data of autocatalytic hydrogen oxidation would help to confirm hydrogen behavior. The calculations discussed here conservatively treat rate of water release and formation of hydrogen. These conservatisms might be reduced through additional analytical and experimental work