Basic results of the Russian WWER-1000 surveillance program

The surveillance test results of the reactor pressure vessels (RPV) of three Russian WWER-1000 type units designated Units 1, 2 and 3 are given and the embrittlement rates compared to those predicted by the Russian Regulatory Guide. The surveillance materials properties measured by manufacturers of the RPVs are reviewed. The chemical compositions indicate low impurity contents (copper and phosphorus) but nickel contents up to 1.9 wt.% in some welds. The Charpy test results were available for the surveillance base and weld metals and the heat-affected zone (HAZ) of the three units. Dependence of the radiation behavior of WWER-1000 RPV steels on metallurgical variables and the damage dose is considered. The trend curves for the steels under investigation are proposed.