Russia’s PA Mayak plans to start-up new electric furnace EP-500/5 for vitrification of high-level waste (HLW) in September, according to the company’s Environmental Safety Report for 2015 published on August 2. Construction of the furnace and an increase in the storage space for vitrified HLW storage at PA Mayak are part of the Federal Target Programme “Nuclear and Radiation Safety”. The construction of the new furnace, the fifth in a series, was completed in December 2015and start-up is planned for September 2016.
Currently the four electric furnaces that operated previously are shut down and liquid HLW is sent to vessels for temporary storage, the report says. Over the entire operating period, these EP-500 electric furnaces (1987-2010) reprocessed 28,112 cubic metres of liquid HLW, produced 6,216t of glass, and vitrified 643m curies of HLW.
Earlier this year, new technology for commercial-scale single-cycle refining of plutonium was launched at Mayak’s radiochemical plant, which recycles used fuel. The basic plutonium refining (clean-up) technology, which has been used at the RT-1 reprocessing plant for years, has two cycles of treatment. The new recycling technology took more than five years of research, laboratory studies, bench and experimental tests to develop and implement, PA Mayak noted. In 2015, extended industrial tests were completed.
Yuli Tadevosyan, head of analytical laboratory of RT-1, said that the new technology “helped to eliminate routine measurements of intermediate-level process solutions”. He added: “For example, now we have stopped working with neptunium concentrates and, as a result, dose burdens to personnel have been reduced.” Konstantin Korchenkin, deputy chief engineer for science at RT-1, said the new technology had no analogues anywhere in the world. “The use of one refining cycle for plutonium removes one extraction section from the process, reduces consumption of some agents, significantly reduces intermediate-level waste and thus substantially increases RT-1’s process and environmental indicators,” he said.
Mayak in 2015 processed more than 200t of used fuel, up from less than 130t in previous years. In future it plans to increase this to 400t a year. Major modernisation is continuing. Mayak reprocesses fuel from VVER-440 reactors, research reactors and submarine reactors. In 2015, the plant achieved the first industrial processing of uranium-beryllium fuel.