Safety assessment of VVER-440's

VVER plants play an important role for electricity supply in Eastern Europe. For the smaller of these reactors, the VVER-440's, the technical concept dates back to the fifties. Thus, the question arises how their safety compares to that of modern nuclear power plants. This subject has now received broad interest also in Western Europe. In the former GDR four VVER-440/V-230 units were operated and an equal number of VVER-440/V-213 facilities constructed at the site Greifswald. Thus, the safety of VVER-440 plants became a relevant issue in the FRG. In early 1990, the Gesellschaft fuer Reaktorsicherheit (GRS) was contracted by the Federal Ministry for Environment Conservation and Reactor Safety (BMU) to assess the safety of the Greifswald units 1-4 with V-230 reactors. The analysis was performed in cooperation with GDR's SAAS (Staatliches Amt fuer Atomsicherheit und Strahlenschutz). The French organization IPSN took also part. The investigation, which reveived strong support by scientific and technical experts from the USSR, was completed in mid 1990. Two IAEA assessments of safety significant event team (ASSET) missions provided complementary information about the safety of these units