Neutronphysical measurements at the start-up of the first block of the Paks nuclear power plant

The physical start-up of the first block of the Paks nuclear power plant was accomplished according to the previous program. Good agreement of the calculation with the measurements could be found in different fields including the determination of the criticalities, that of the symmetries of the reactor core, the differential and integral worths of the control rods, and the reactivity coefficients. The construction principle of the temporary measuring system and the applied modifications are discussed in detail. (V.N.)