Nuclear Fusion is often presented as the Holy Grail of electricity production. This website shows why it is very difficult to achieve and why it may never be a reality.
Two possibilities for nuclear power generation exist, one in operation for 70 years, fission, and one which has been in development for the same period, fusion. Features of fusion and fission power production are compared showing advantages claimed by fusion advocates are exaggerated.
To achieve a gain in energy output, fusion reactors must attain certain conditions of plasma temperature; plasma density and confinement time. These quantities enter the "Triple Product" which is used to compare progress of already constructed fusion devices with that required for an actual fusion power reactor.
After decades of research, most efforts towards fusion power are based on magnetic confinement fusion with tokamak devices. The ITER machine, in construction since 2007, is the latest such device and it is planned to follow on with a number of demonstration fusion power plants before the final goal of commercial fusion power plants.
This page presents the many immense challenges for tokamak fusion power plants using deuterium-tritium fuel. Some of the problems discussed for a commercial reactor may be insurmountable.
The materials in a reactor must survive damage from the enormous flux of neutrons emitted from the fusion reactions. This problem is as yet unsolved and requires extensive R&D using test facilities which are not yet available.
The neutrons from fusion reactions make certain materials radioactive via neutron activation. This will produce large volumes of radioactive waste which must be managed for 100s or even 1000s of years.
The supply of tritium is the biggest challenge for the mainstream approaches to fusion power. Because of radioactive decay (half-life 12 years) the quantity of tritium naturally occurring is small and essentially all tritium supplies come from CANDU fission reactors. In a few decades most of these special reactors will stop operations and the global supply of tritium will decay away before commercial fusion reactors can be brought into operation.
The Breeder Blanket is the most critical and complicated component of a fusion reactor because of the dual functions of heat extraction and tritium breeding. Much remains to be done for the decision on the optimum technology and this also necessitates a test facility.
The divertor is the device which implements the exhaust of the plasma at the end on a confinement cycle. The limiter scraps the edge off the plasma in disruptions and complements the role of the divertor. These components have the highest radiation damage in the tokamak because of the high dose of neutrons they receive.
Superconducting magnets are the core enabling technology for magnetic confinement fusion reactors. The reliability of the magnets is essential for the operation of a fusion power plant.
The reliability of components in a fusion reactor is essential to give high availabilities to generate electricity. Because of the complexity of reactor systems, there is concern that the availability of fusion reactors will in fact be low.
For current fusion projects, the physical size of the tokamak and the complexity of the associated systems required for operations, raise doubts that commercial reactors of even bigger scale could ever be viable.
Safety is often evoked to suggest that fission is preferable to fusion. Risks from fusion reactors are different from fission reactors, however significant risks do exist for fusion power plants.
The cost of fusion, relative to other electricity sources, will be the primary decider for commercial power. Estimates from literature are presented, together with new estimates, based on simple arguments. The conclusion is that the cost of fusion must be 5 -10 times more than fission.
Two aspects of R&D for fusion reactor, materials and tritium breeding, need special test facilities which do not exist yet, despite pleas from engineers for decades. The situation for these facilities seems to reflect a lack of realism from some funding organizations. These facilities must play a major role in the next steps of fusion developments.
After ITER, plans diverge around the world for arriving at commercial fusion power. Given the conclusion of this website is that the technology will never work, arguing about details of schedule is rather academic.
The mainstream approach toward commercial fusion reactor has major "show-stoppers". This page summarizes problems discussed throughout this website.
Fusion power only really makes sense if it has clear advantages over fission power. Fusion advocates claim this is the case, but this page summarizes the arguments that fusion has, in fact, no significant advantages over fission.
Alternative approaches exist to the mainstream methodology of magnetic confinement fusion with tokamaks and D-T fuel. As on this website, many experts have concluded the mainstream approach will never work and have launched new fusion activities based on private finance. These new approaches include innovations to magnetic confinement fusion as well as inertial confinement fusion and hybrid techniques.
This website has come to the conclusion that the mainstream fusion approach will never come to fruition with an economy of commercial fusion power plants. Following this, a page was introduced detailing alternative approaches. On this page a final conclusion is given expressing the opinion of the author on the whole fusion enterprise.