Thorium is not a solution
von REINHARD WOLFF Norway gives up plans to build a thorium reactor, after a study has shown. Safe and clean nuclear power is not with the fuel of uncleavable REINHARD WOLFF
Now Norway is so far. The local Radiation Protection Authority Statens Strålevern allow all plans for the construction of a thorium reactor, a rejection. Both Environment Minister Erik Sohlheim and Economy Minister Sylvia Brustad at the close.
The red-green government in Oslo in 2007 had been at Statens Strålevern commissioned a study. At that time, the strong lobby of thorium had started a debate about the supposed benefits of this technique, the state power company Statkraft initiated, to indicate interest for a reactor. Norwegen verfügt vermutlich über die drittreichsten Thorium-Vorkommen der Welt. Norway has probably the world's third richest thorium deposits in the world.
The Norwegian parliament has banned the construction of nuclear power plants 30 years ago by law. And it should remain under the present ruling of the Radiation Protection Authority probably. In their report Statens Strålevern examined the entire thorium fuel cycle from extraction to nuclear waste storage. Result: "Conventional reactors, regardless whether they are based on uranium and thorium fuel, lead to radioactive contamination of air and water, in both cases there is a significant accident risk, especially with regard to uncontrolled chain reactions and at worst a meltdown."
Reactors, which operate with thorium were so similar adverse environmental consequences and a similar risk as those with potential uranium fuel. Of thorium supporters just before the supposed safety as a core melt is brought into the argument field. The minerals from the radioactive metal thorium extracted Thorite is not fissionable. Thorium as fuel must therefore be supplied from outside neutrons to start the chain reaction producing energy and keep going. If this is set, it also stops the reaction.
According to the Radiation Protection Authority but does not mean that there is no risk of accident to a nuclear meltdown. Also for the removal of residual heat-functioning cooling systems were needed: "The probability of a meltdown is to be judged on uranium or thorium fuel immediately."
A thorium reactor while producing less and less long-lived nuclear waste than a nuclear power with uranium fuel rods. This is also more stable than conventional nuclear waste. But he radiates stronger, which complicates transport and storage.
The decisive point, however, the study shows that the thorium technology does not solve the nuclear waste problem. It adds even during operation of the reactor, a much higher radiation levels. Even the safety-thorium-use offer little advantage: Although only small amounts of plutonium fell on, and this is also for the production of nuclear weapons is not particularly interesting. But in the hands of terrorists could also thorium reactor for "non-peaceful purposes" are used.
The verdict is not much better for the hitherto existing only on paper thorium-concept Accelerator Driven System (ADS), a combination of a particle accelerator and a lead-cooled reactor from. It is true that the risk of a meltdown here really low, they say. The 8,000 to 10,000 tonnes of lead metal of his cooling system could absorb the residual heat from the core probably. But such a construction due to the combination with a particle accelerator as a whole is vulnerable. At the same time it will come to a radioactive contamination of the entire cooling system. There's also a completely clear whether this technique could be implemented in 20 or 30 years to economically acceptable cost.
"The debate should now be thorium is a closed chapter," Nils Bohmer, believes nuclear expert at the environmental organization Bellona, "Hopefully, the policy now busy with real solutions to the climate problem."