The 50th Anniversary of the WWR-K Research Reactor

Abstract

The WWR-K is a multipurpose research reactor in the Republic of Kazakhstan. The WWR-K reactor was started up for the first time on October 30, 1967, under the direction of B.T. Dubovsky, V.N. Okolovicha, G.A. Batyrbekova, L.A. Yurovsky, and A.I. Maslova. The WWR-K research reactor is a water-water reactor of a heterogeneous type with a thermal neutron spectrum, a rated capacity of 10 MW, and a 36% enrichment of uranium-235. The reactor operated without any accidents until 1988. After the Chernobyl accident, the USSR Gospromatomnadzor decided to suspend the operation of the WWR-K reactor in October 1988 until the requirements for ensuring safe operation of the reactor under high seismicity conditions were met. Specialists at the Institute of Nuclear Physics endeavored to increase the seismic safety of the reactor and to provide for its safe operation in conditions of high seismicity. In 1998, the operation of the WWRK reactor was resumed with the permitted power of 6 MW. Prior to the collapse of the USSR, the main purposes of the WWR-K reactor were testing the thermionic reactor-converter elements, neutron activation analysis, studies of ultracold neutrons, studies of inert gas plasma parameters, and studies of the electroionization of CO2 and CO lasers. In 2003, a feasibility study was begun for the conversion of the reactor to lowenriched fuel with preservation of operational and experimental capabilities. As a result, a new fuel assembly, WWR-KN, was designed on its basis—a compact core, which allows improving the characteristics of the reactor. During the period from 2011 to 2013, the life-cycle tests of three test assemblies were conducted; on the basis of the test results, the WWR-KN FA was recommended for the conversion of the WWR-K reactor. In the first half of 2016, successful physical and power startups of the WWR-K reactor with low-enriched fuel were carried out. As a result of the conversion, the thermal neutron flux in the center of the core was doubled. The main current purposes of the WWR-K reactor are the following • testing fuel and structural materials of reactors of the fourth generation; • testing fusion reactor materials; • producing radioisotopes for medicine and industry; • neutron activation analysis.