Performance comparison of dry and vapour suppression containments

Variation of peak pressure and post accident heat removal load with various ratios of volume of dry well to that of wet well of vapour suppression type containment is studied. Variation is evaluated in terms of equivalent dry containment for which two parameters, namely, containment efficiency for pressure suppression and containment efficiency for energy dump are defined and investigated. An efficient pressure suppression system requires a low dry well to wet well ratio combined with a high vent floor area. Practical considerations impose restraints on these parameters. The above studies help to arrive at optimum containment design for given restraints. A sample problem of one million cft of containment volume, chosen as a representative of PHWR, has been solved and results are presented. (M.G.B.)