A measurement system for leak testing between primary and secondary cooling circuits of a nuclear power plant

A simple semi-automatic measurement arrangement using Hungarian-made instruments has been installed at Unit 2 of the Paks Nuclear Power Plant, Hungary. It can be used for measuring possible leakage between primary and secondary cooling sides at the steam generators. The cooled water sample of the secondary circuit taken from one of the six steam generators is conveyed by a sample changer automatically to high sensitivity NaI/Tl/ scintillation detectors that produce signals for a two-channel discriminator. The channels monitor 42K and 24Na activity, resp. The sensitivity of the system is about 10 Bq/l, depending on the background radiation. (R.P.) 3 refs.; 3 figs