About the GIF

Frequently asked questions: Generation IV defined

I've heard a lot about Generation IV reactors. What are they and what are Generation II and III reactors?

Most reactors currently in operation are Light Water Reactors (LWR) of Generation II or, for the more recently constructed plants, Generation III design. Generation IV (Gen-IV) reactors are innovative reactors that will enable nuclear energy to meet the energy needs of the future while also complying with the concept of sustainable development, in particular relating to more efficient use of uranium and optimised management of nuclear waste. Gen-IV reactors will also exhibit enhanced safety, competitiveness and proliferation resistance. However, it will take two or three decades to bring such systems to industrial maturity. Read more...

So, in what ways will Generation IV reactors be different from today's reactors? Does this mean that present day reactors are unsafe, unsustainable and dirty?

(Has Gen-IV got anything to do with nuclear fusion? But why should we back both generation IV and fusion ... if fusion is successful, won't this make Gen-IV obsolete?)

Compared with present day LWRs, Gen-IV reactors will mainly offer greatly increased uranium resource sustainability, reduced high-level radioactive waste production and the possibility of cogeneration of electricity and process heat. Existing nuclear power plants are operated to high and internationally accepted levels of safety, and Gen-IV reactors should reach safety levels at least as high as those of Gen-III reactors. Fusion energy is still a long way off and will reach the stage of commercial exploitation later than Gen-IV. Nevertheless, when this time comes it will be a welcome contributor, along with fission energy, to the world's future low carbon energy needs. Read more...

Will Generation IV reactors help us to achieve our ambitious CO2 reduction targets, improve security of energy supply/competitiveness?

In the longer term, Gen-IV systems will help to reduce CO2 emissions and to improve security of energy supply at a stabilised affordable cost, within a context of increased sustainability compared with present reactor designs. In the shorter term, economic and environmental benefits can be assured through continued operation of existing plants and by the construction of Gen-III reactors. Read more...

So, Generation IV means widespread use of fast breeder reactors and therefore reprocessing ... but won't this mean we need more large reprocessing plants like at La Hague and Sellafield, leading to more low-level radioactive waste and increased radioactive effluent discharges to the environment?

These new reprocessing plants will enable all the minor actinides produced in the reactor to be recycled back into fresh fuel ... this might be good to reduce the proliferation risk, but won't this lead to increased radiation exposure of workers in both the reprocessing and fuel fabrication plants?

But surely we cannot recycle everything...exactly how much highly toxic radioactive waste will be produced each year by a typical Generation IV reactor, and how does this compare with current reactors? Won't this mean we'll still need to find a solution to long-term management of such waste, e.g. construction and operation of geological disposal facilities?

Long-term uranium resource sustainability requires the introduction of the fast breeder fuel cycle, which means as well as the reactors themselves, appropriate fuel recycling (or reprocessing) plants must also be available. However, these must be operated to strictly enforced high levels of safety, workforce protection and environmental norms, in particular relating to discharge of radioactive effluents. Gen-IV reactors will still produce quantities of radioactive waste that require long-term management in geological disposal facilities. However, quantities and radiotoxicity will be less than from current designs. In the case of fast reactors, this waste will be limited to fission products since the minor actinides would have been recycled. Read more...

The availability and extent of uranium reserves and the associated cost is a controversial issue; is there any impact on the deployment strategy of Generation-IV systems?

Clearly the availability of uranium reserves is one of the drivers for the development of fast reactors, which constitute an important element of Generation-IV systems. However, this is not the only driver for Generation-IV technology as a whole. Other aspects such as waste management, safety, competitiveness, proliferation resistance and co-generation of heat and electricity also play an important part. In the end, the promise of Generation-IV technology is that it will offer many advantages in a number of areas, irrespective of the extent of uranium reserves. Read more...

Watch an Introduction to Generation IV Nuclear Energy Systems and the International Forum (requires Adobe Flash Player, or download in pdf format, 1.2 mb)

Download an Overview of the GIF (pdf, 161 kb)

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