Modified CANDU Reactor MCR as an Early-Deployable Nuclear Workhorse

Abstract

Safe, simple and soon deployable are the imperatives for each SMR concept today. Only this SMR has the potential to become a nuclear workhorse in the fight against climate change if it is available soon, in large numbers and deployable worldwide. Therefore the assessment of the usefulness of an SMR concept must not only relate to the reactor itself. Only a holistic view of the entire nuclear fuel cycle with the given SMR as the central part between the front-end and back-end can lead to viable decisions. The IAEA lists more than 120 SMR concepts in its Handbook 2022. Time pressure is forcing us to critical selection of a promising reactor concept and to combine innovative solutions with tried and established technical and administrative networks. Against this background, the Modified CANDU Reactor (MCR) is proposed as additional SMR design. The MCR has two obvious modifications compared to the well-known and globally proven CANDU design: a) spherical fuel elements (pebbles) with ceramic cladding b) vertical arrangement of the pressure tubes. Intended for the generation of heat and electricity close to the consumer, the construction of a plant with MCR is preferably carried out underground close to the surface. The Herrenknecht VSM-shaft-tunnel technology is planned for the construction of the structures. For the transportation of irradiated fuel elements, (extended) interim storage and final disposal, technologies are proposed (Initial Barrier; TRIPLE C) that have already been published elsewhere. In order to provide a basis for further scientific and technical discussions, an attempt was made to incorporate the MCR concept into the existing CANDU SMR TM design. The resulting combined “overlapping” concept has not yet been discussed with the CANDU developing and operating countries. The authors hope for a fruitful discussion and are looking for future cooperation with the CANDU SMR TM manufacturer (CANDU Energy Inc. Canada), as well as with the countries that traditionally use CANDU reactors (China, India, South Korea) and Norway in future maybe too.