Note: a further comment has been provided by Rudo de Ruijter, Independent researcher,
Link added in Comments below.
“Die ich rief, die Geister,
From the spirits that I called,
werd'ich nun nicht los.
Master, now deliver me!”
Goethe, The Sorcerer’s Apprentice
- Renewable resources must NOT be used faster than they grow or can be regenerated
- NON-renewable resources (e.g. oil, gas) may be used only to the extent that renewable resources can NOT be made available.
- To ‘switch off’ an atomic power station, or to take it off-line in more technical parlance, requires the careful gradual insertion of control rods among the fuel rods in order to slow down the chain reaction of the nuclear fission process.
- During this process, the first 20 to 30 hours are extremely critical because the heat produced is no longer withdrawn by steam for power generation and the fuel rods get hotter. An increased cooling effort is required, not only with water but also with special coolants to keep the fission process within manageable limits.
- After this initial period continual cooling of the reactor is a more normal routine. [the working temperature of a nuclear reactor is around 800ºC. It is claimed that the switch-off process can be routinely mastered].
- This requires some remarks about the Chernobyl accident. The operators of the plant wanted to simulate an emergency, disconnected several safety systems in order to test what might happen and how one would need to react.
- During this emergency exercise, which also involved temporary reduction in cooling systems, the reactor over-heated to an extent that the control rods were no longer able to slow down the reaction and the rated heat output was exceeded by a factor 100.
- This emergency exercise was carried out over several days so that changing teams of operators were put to test in a shift system.
- The fuel rods in nuclear reactors generally last for five years producing power in accordance with their design specification through nuclear fission, i.e. they boil water which powers steam turbines which in turn drive generators which finally produce the actual electricity.
- At the end of their useful life the spent fuel rods are retrieved by robots from the reaction vessel and must be stored in cooling basins within the reactor building because of their high temperature of about 800ºC. The on-site cooling period varies between one and five years. Once cooled, these spent fuel rods were then (until 2005) transported to La Hague in France or to Sellafield in the UK to be reprocessed, i.e. 1-5% of the residual uranium are chemically extracted for use in new fuel rods.
- To stay briefly with reprocessing: the remaining nuclear waste (95-99% of spent fuel rods) remains highly radioactive and is fused with borate glass at a temperature of 1100ºC and poured into stainless steel tubes and sealed by welding; these cocoons have a diameter of 40cm and are 1.40m long.
- The waste products in a fuel rod represent about 90-99%, the remaining 1-10% yield during reprocessing uranium and plutonium for re-use as fuel rods.
- A nuclear power station with an output of 1,300MWp (the size of recent German power stations) produces about 50m3 per year of low heat producing radioactive waste,
- During reprocessing, a further 10m3 of low heat producing radioactive waste arise
- In addition app. 3m3 highly radioactive fission products need to be dealt with
- German nuclear power stations produce 450t/year of highly radioactive spent fuel rods
- Worldwide, 12,000t/year of highly radioactive waste are produced; by the end of 2010 a total of 800,000t has accrued, of which 70,000t in the US alone.
- In Germany, the costs for dealing with nuclear waste are exempt from the general principle of the originator being liable for safe removal or storage. The result is that the taxpayer instead has to bear these costs, e.g. € 3million for nuclear waste transports alone, not to mention any other measures for dealing with the sheer never-ending problems with nuclear waste.
- For a German NPS with an output of 1,300MW the total radioactive ‘inventory’ has only a marginally higher radioactive content than a SINGLE Castor container.
- The content of a single HAW CC is the approximate equivalent of 20% of the nuclear inventory released during the Chernobyl accident.
- The Gorleben storage depot for cocoons is licenced to contain the radioactive inventory of 2,000 HAW CCs (that’s 56,000 cocoons).
- A single unshielded HAW cocoon has a surface radiation power which is lethal for humans within 60 seconds at a distance of 1.00m.