Activation Analysis of the Reactor Pressure Vessel of HTR-PM Reactor Using FLUKA Code

Activation products are the primary radiation source in the maintenance of the reactor pressure vessel (RPV) of High temperature reactor pebble-bed module (HTR-PM). In order to properly plan the maintenance and reduce the related occupational exposure, it is important to correctly evaluate the activation of the impurities in the metal material of HTR-PM’s RPV. In this study, activation of the material of HTR-PM’s RPV is performed using both FLUKA program and experimental formula. Based on the impurity control limit in the technical specification, various impurity nuclides are taken into account. The specific activities of activated radionuclides calculated by the two methods after 40 years irradiation and at the shutdown time are compared. It is demonstrated that FLUKA and experimental formula are in agreement. Also primary contributory activation products at 30 days, 1 year, 5 years and 10 years after the shutdown time are listed.