Summary

Generation IV reactors (Gen IV) are a set of advanced nuclear reactor designs aiming to improve on safety, sustainability, and efficiency of the previous Generation III and Generation II reactors currently in service. There are six reactors designs currently in R&D: high-temperature gas-cooled reactor (HTGR), very-high-temperature reactor (VHTR), molten-salt reactor (MSR), supercritical-water-cooled reactor (SCWR), gas-cooled fast reactor (GFR), sodium-cooled fast reactor (SFR), and lead-cooled fast reactor (LFR).

Viability (3)

All of the six designs are at different stages of the R&D process. All six have progressed past proof of concept and fall between proof of performance and proof of operations. Progress is coming from China with a working HTGR prototype and Russia has a LFR scheduled for completion in 2026. Commercial viability is yet unproven nuclear utility, based on experiences with prototypes, that an advanced design can be built on time, within budget, and operated at a profit.

Drivers (3)

The drivers for nuclear power generally are as a low-carbon reliable power source. All six Gen IV designs are driven for the need to improve Gen III reactors in terms of sustainability, economics, safety, reliability and proliferation-resistance to make adoption faster and easier. In particular, the most popular and cheapest low carbon sources are unable to deliver consistent electricity or generate very high heat outputs. Both of which are required to decarbonise electricity generation and heavy industry.

Novelty (2)

Gen IV reactors compete with other types of energy sources on safety, reliability, sustainability, efficiency and cost. Nuclear is highly efficient and reliable making it an ideal candidate for baseload electricity generation. It also generates high temperatures making it useful for applications that need high temperatures like heavy industry. Although CCUS and biomass are alternatives to solve the same problem.

Diffusion (2)

Gen IV will face the same barriers to adoption as Small Modular Reactors (SMRs) including licensing, cost, radioactive waste, public safety concerns. Gen IV will however be safer, have higher yields, and use materials with a shorter half-life. However the competition for electricity generation and especially the cost advantage of solar/wind and batteries will make adoption difficult. There is greater potential as a heat source for decarbonisation of high heat applications although this is not how Gen IV is positioned today.

Impact (3) High certainty

It’s hard to make a high impact case for Gen IV with so many competing cheaper low-carbon energy sources for electricity generation with a 20 year head start. Reliability will likely be solved by batteries by the time Gen IV arrives. As a high heat source Gen IV holds promise but would compete with CCUS which may have a 10 year head-start and other decarbonisation methods for heavy industry including new materials.

Timing (2025-2030) High certainty

The Generation IV International Forum which is coordinating R&D has a roadmap for commercialisation of at least one reactor design by 2040. However the urgent need for low carbon baseload energy will likely deliver a working reactor in the 2030s probably in China or Russia first. The repositioning of nuclear as a heat source not for electricity generation will drive public investment in the early 2020s.