Radiation problems of functional testing of nuclear power plant equipment at an electrophysical installation of the INR of NAS of Ukraine

Abstract.

Purpose. The purpose of the research is the creation of a domestic research complex for operational complex qualification tests of equipment samples of the Ukrainian power units. It is shown that it is advisable to create such a complex on the basis of the radiation installation of the Institute of Nuclear Research of the National Academy of Sciences of Ukraine with a powerful electron accelerator of 4 MeV, subject to the modernization of radiation protection.
Methods. The method and program of measures developed to measure the intensity of radiation fields in the premises of the INR of NAS of Ukraine experimental installation and in adjacent territories in the generation modes of intense electron fluxes, bremsstrahlung gamma radiation and mixed gamma electron radiation fields similar to the conditions of nuclear reactor pressure zones are discussed. A list of associated effects affecting the radiation situation in the premises of the facility and in the surrounding area during irradiation of critical equipment with a high content of heavy metals has been theoretically investigated. The expected intensity and spectrum of bremsstrahlung and scattered gamma radiation has been established.
Results. The necessity of carrying out experimental studies of real radiation fields in various modes of functional radiation studies of equipment has been substantiated. A program of radio monitoring has been developed through a dosimeter system in the reconnaissance chamber of an INR facility, technological rooms and beyond. An optimal list of sensors for radiation monitoring dosimeters has been selected and substantiated in the mode of irradiation of critical equipment important to NPP safety, primarily electrical engineering (for example, electric actuators of type M 76341, cables, germprojects, insulators). The current problems of developing certification technologies and qualifying critical equipment for pressurized nuclear power plants using specialized radiation stands capable of simulating (reproducing)
in a complex all the components of operational factors and recording the entire list of technical parameters characterizing the object of research are investigated.
Conclusions. The perspective directions of improving the certification technology and qualification of critical equipment of the nuclear power plant containment area are investigated. It has been established that the condition for obtaining correct results is the use of specialized radiation stands capable of modeling in a complex all components of operational factors and recording the entire list of technical parameters characterizing the object of research. It has been proven that with the improvement of the biological radiation protection system, the installation can be used to simulate radiation fields in the hermetic zones of nuclear reactors and carry out functional radiation tests of nuclear power plant components, with dimensions up to 800 mm. The necessity of experimental studies of real radiation fields in various modes of functional radiation research of equipment is substantiated

Keywords: qualification of NPP’s equipment, radiation fields, bremsstrahlung, radiation monitoring, radiation protection

10.24144/2415-8038.2019.45.61-72