Lifetime of automated control system of technological processes of nuclear power unit and its updating

For the analysis of their physical lifetime, components of automated technological process control systems at WWER nuclear power plants are divided into three categories, viz., irreparable equipment, equipment reparable during unit shutdown, and equipment reparable during the unit operation. Conditions for the innovation and upgrading of automated control systems at Czechoslovak WWER-440 nuclear power plants are discussed. Presumably, at the Bohunice V-2 and the Dukovany nuclear power plants the innovation of these systems will proceed in a manner similar to that applied at the Loviisa nuclear power plant in Finland. The decision concerning the global upgrading should be postponed until experience is gained with the new automated control system that will be installed at the first unit of the Mochovce nuclear power plant. The upgrading of the automated control systems at the two Bohunice V-1 power plant units poses specific problems, particularly with respect to the assessment of the true physical lifetime of the technological equipment and to the finding of the best approach to the upgrading. (Z.M.). 2 figs