EXPERIMENTAL INVESTIGATION OF RADIATION EMBRITTLEMENT EFFECTS OF LOW COPPER REACTOR PRESSURE VESSEL STEELS

The radiation embrittlement of two types of low copper reactor pressure vessel steels is studied. The relation between the material damage embrittlement extent and irradiation parameters such as fast neutron flux、 fluence and temperature is investigated, so with the test data of SA508 3 steel irradiated in the test reactor to be correlated to PWR pressure vessel surveillance test data. The advanced instrumented impact test equipment and the method for treating test data with the hyperbolic tangent function ensure the accuracy of results. Instrumented charpy V notch data was converted into dynamic fracture toughness by means of semi empiric formula. This investigation provides reliable data on the material irradiation embrittlement for predicting lifetime of pressure vessels in operation or in design.