Beneficiary Organization Details

Kozloduy NPP (Bulgaria)
http://www.kznpp.org

Project Aims

• To define the actual conditions of the material of weld No 4;
• To evaluate the rest life time of the Reactor Pressure Vessel of Kozloduy Unit 1 on the basis of a minimum required data, to serve within a reasonable short time for decision making with respect to future operation of the plant for the Plant management and for the Bulgarian Nuclear Safety Authority.

Project Results

• Six samples were removed from the weld metal of weald seam No 4 in the region of maximum neutron flux for evaluation of material properties in the actual and annealed conditions. On the basis of these results, the Tk values were determined and compared with the allowed Tk values, given by thermo hydraulic and RPV integrity calculations of relevant PTS events;
• In addition it was performed accelerated irradiation in a host-reactor to get more precise information on the future material behaviour under irradiation and to develop a reliable basis for rest-life-time prediction of the RPV.

Further Project Results

Further information on the project results could be sought from the beneficiary organizations.