The PMK-NVH experimental facility and the phenomena to be investigated

The integral-type PMK-NVH test facility is a 1:2070 scaled model of the primary circuit of the WWER-type Paks Nuclear Power Plant. The operating pressure and temperature are 16 MPa and 623 K, respectively. The elevations are the same as in the plant. The scheduled time for the start-up is the end of 1984. The loop was designed for SB LOCA experiments above all, but operational transients can also be investigated. Paper presents the system description including instrumentation, control system and data acquisition. Some important phenomena to be expected from SB tests as they could be derived from pre-test calculations are also presented. The effect of the loop seals on the natural circulation, normal or reverse heat transfer in steam generators, core heat transfer at reduced primary circuit inventory are included. (orig.)