The VNIIEF Research Center in Sarov, one of Russia's nuclear weapon laboratories, is planning to open production of medical isotopes on an Argus-M reactor, which is a modified version of the Argus aqueous homogeneous reactor at the Kurchatov Institute. That reactor was converted to LEU in 2014. The reactor in Sarov will also use LEU.
At the public hearing on the Argus-M reactor project, held in July 2017 in Sarov, Rosatom presented its estimate of the status of the Mo-99 market and provided some information about the isotope production in Russia.
According to Rosatom estimate, market shares of the key Mo-99 producers are as follows: ANSTO (Australia) - 10%, Nordion (Canada) - 20%, Mallinckrodt (Netherlands) - 31%, NTP (South Africa) - 20%, IRE (Belgium) - 14%. Rosatom's own share in Mo-99 production is 4%.
Until recently, the main Mo-99 producer in Russia was the Obninsk branch of the Karpov NIFKhI, which produces about 170 Ci/week. There were also two "regional producers" - the Khlopin Radium Institute (St-Petersburg) and the Tomsk Polytechnic Institute. Several years ago production of the isotope began at NIIAR in Dimitrovgrad.
According to Rosatom, three out of four producers (NIIAR, Tomsk, and NIFKhI) use HEU reactors, two out of four (NIFKhI and NIIAR) use HEU targets. NIFKhI and NIIAR use fission fragments technology, Tomsk an the Khlopin Radium Institute use neutron activation.
The reactor at the Obninsk branch of NIFKhI is the VVR-Ts, the reactor in Tomsk is IRT-T. NIIAR apparently uses several reactors to irradiate the targets. The Khlopin Institute does not operate a reactor. It irradiates Mo-98 targets in RBMK reactor of the Leningrad Nuclear Power Plant.
UPDATE: At an IAEA meeting "Opportunities and Approaches for Supplying Molybdenum-99 and Associated Medical Isotopes to Global Markets" held in July 2017 in Vienna, Rosatom representative presented a different set of numbers. The production capacity of the NIFKhI in Obninsk is said to be 350 Ci/week, that of NIIAR - 1000 Ci/week.
It should be also noted that Nordion stopped producing Mo-99 in 2016. Taking these corrected numbers into account, Russia's production capacity is closer to the 12% of the global capacity and 25% of the global demand. (Thanks to Alan Kuperman for the correction.)