Six Russian SMR designs16 January 2019
Russian N.A. Dollezhal Research & Development Institute of Power Engineering (Nikiet) has developed a number of SMRs based on earlier power plant designs. In an interview with NEI, Denis Kulikov, Nikiet’s chief designer of reactor facilities for small nuclear power plants, offers an overview.
Nikiet is working on a variety of small modular reactor designs based on traditional integral pressurised water reactors and high-temperature gas-cooled reactor technology. The range of generated electric power is 1-100MW, with a typical 60-year operating life.
One of Nikiet’s proposed transportable designs is the 1MWe (6MWt) Vityaz modular plant, for decentralised power. Vityaz is a functional and ready-to-operate nuclear power plant comprising four transportable modules with a weight of up to 60t, deployed on high-mobility wheeled platforms. It is based on an integral water-cooled water- moderated reactor. Electricity is generated by two turbine-generators, and heat supply by cogeneration is also possible. Most of the engineering approaches employed have been adopted from facilities already in operation.
The ATGOR gas-cooled reactor is at the heart of an even more compact design for a combined transportable small plant. The power unit can include up to six parallel commercial gas-turbine engines with two independent heat sources - a nuclear reactor and a start-up diesel fuelled combustor. This provides for a shorter start-up time.
Some small standardised nuclear plants are based on the Shelf reactor. The SNPP generates 6.6MW of electric power and has a thermal power of 28MW. The basic version was developed in 2010, and offered underwater deployment of the power capsule with an integrated turbine-generator plant. Later, following a potential customer requests, land-based designs were developed. Deployment of Shelf requires no major research or technology development activities. Once an agreement with a customer is signed and the technical assignment approved, it would take an estimated five years to finalise the design development, licensing, construction and commissioning.
Unitherm, a reactor with a capacity of 30MWt or 6.6MWe, is based on Nikiet’s experience in designing marine nuclear installations. For maximum radiation safety three circuits transport heat from the core. The reactor, with passive safety systems and devices, offers long-term periods of standalone unattended load-following operation using centralised regional monitoring for its support facilities. The reactor is capable of operating for up to 25 years without refuelling.
The NIKA-330 reactor is intended for use as part of a 100MWe nuclear plant. It comprises an integral reactor with a core life of 4.5 years, excluding outages for maintenance. All primary circuit components not requiring in-service maintenance, including the pressurizer, are installed inside the reactor vessel. Its passive safety features do not require any direct operator intervention for at least 72 hours following an accident.
Karat-45, a small tank-type boiling water reactor (BWR) with a rated power of 45MWe, is an independent cogeneration plant for producing electric power, steam and hot water. The larger Karat-100 has a power output of 360MWt or 100MWe. The design includes natural circulation in its core cooling system for heat removal in all operational modes and incorporates passive safety systems for enhanced safety and reliability. A prototype direct-cycle BWR has been working for 50 years.
These reactors are at different stages of design. Some, such as Shelf, have their detailed designs completed. Nikiet has a number of potential buyers for the technology in Russia and we are now working towards building a prototype. A pilot reactor for demonstration and testing will be also required for international customers.