Analysis Of The Startup Physics Tests Of A Vver-1200 Reactor With The Karate-1200 Code System

Two Generation III+ VVER-1200 units are planned to be built in Hungary. Investigation of core improvements made for the new reactor type has been done by the vendors. However, appropriate independent calculation tools are advantageous for the users, among others, for strengthening the safety level. Recently several new VVER reactors have been commissioned; among them three VVER-1200 units. To determine experimentally neutron-physics characteristics of those units, similar startup test programs were performed and extended with some new, unconventional measurements. Several experiments from the physical startup of a VVER-1200 were published recently. This contribution summarizes the experience gathered at MTA EK with the newly developed KARATE-1200 code system on the basis of the reactivity measurements obtained from the literature.