Full-scale tests of ICMS for VVER-1200 during commissioning Novovoronezh NPP-2 unit-1: features and results related to the coolant temperature monitoring at a core entrance

28th Symposium of AER on VVER Reactor Physics and Reactor Safety (2018, Olomouc, Czechia)
[4] Core surveillance and monitoring


Iu. Saunin, A. Dobrotvorski, A. Semenikhin, R. Zubcov, S. Ryasny (JSC Atomtechenergo)


The primary circuit coolant temperature at a core entrance is one of the key parameters during operation of NPP power units with VVER. These parameters are used to monitor and operate according to the requirements of power units safe operation regulations. Therefore, as much attention as their importance is given for the full-scale testing of ICMS during commissioning and operating. Based on the results of full-scale ICMS tests during commissioning Novovoronezh NPP-2 Unit-1 it is informed about the first practical experience of the coolant temperature monitoring at a core entrance of VVER-1200 reactor using thermocouples in the in-core detectors assemblies of KNIT type.

Data about fulfilled tests at all stages of commissioning are given and the main results of the performed analysis are shown. The reliability problems of information obtained by means of the considered method of monitoring are presented and the made decisions during commissioning are noted.