First one reactor exploded, then another and now a third has gone. Newspapers all over the world are carrying one single, horrifying word on their front pages: \’Meltdown\’.
The news this morning has been stark. A third reactor at the Japanese plant has now been rocked by an explosion. Officials now fear that the explosion could have caused a crack to develop in the reactor core allowing radiation to escape into the atmosphere. A commentator on Yahoo who lives in Japan has reportedly heard on the Japanese news that the explosion blew off the roof and walls of reactor 2, which are constructed from 2 metre thick concrete. Apparently the news item also reported that the second explosion sent a huge chunk of concrete flying through the wall of reactor 2. A fire was also reported to be raging through reactor 4 but according to the International Atomic Energy Association (IAEA) this has now been extinguished.
According to the Bellingham Herald, Japanese officials are now starting to admit that they have a very serious problem on their hands. Yesterday they told the Japanese people that the threat from radioactive fallout has increased dramatically because the explosions at the plant may have breached a reactor\’s inner containment vessel. \”Radiation levels around the compound have risen to fairly high levels,\” said Naoto Kan, the Japanese Prime Minister during a morning news conference this morning. He also warned that \”there is a danger of even higher radiation levels.\”
Kan reported yesterday that 400 millisieverts of radiation were detected at the plant at around 10.30. This is about 20 times the amount of radiation that a nuclear worker is allowed to be exposed to annually. The official advice is that anyone within an 18-mile radius of the plant should stay indoors. It seems that everyone within a 12 mile radius have been evacuated, nevertheless officials maintain that swift action should be able to minimise the effect on human health according to a report on the BBC News website this morning.
At the moment, according to Professor Gerry Thomas, from Manchester University, providing the Japanese authorities act quickly there should be no danger of this incident turning into a second Chernobyl. Nevertheless, the Japanese website Nikkei.com reported on Saturday that the first explosion was due to a meltdown of the rods inside the reactor on the basis that radioactive cesium and iodine were detected immediately outside the plant. This has been rejected by others as being somewhat premature although according to Yahoo News Japanese officials admitted to reporters late on Monday that this could indeed by happening. Apparently the chief government spokesman has told reporters that there were signs that rods in all three stricken reactors, all of which had lost their cooling systems, were melting. \”Although we cannot directly check it, it\’s highly likely happening,\” Chief Cabinet Secretary Yukio Edano is supposed to have told reporters. Japan has now asked the IAEA for help.
So, this is the situation that has greeted the world this morning. But what actually is a \’meltdown\’? Could such a thing happen in the UK? Is nuclear power such a good thing after all?
A meltdown is a particular type of nuclear accident which involves damage to the reactor core from overheating, primarily as a result of the reactor cooling system, such that the fuel rods within the core overheat and melt, either partially or completely. This is what appears to be happening in Japan at present. A meltdown can occur either from a loss of pressure or a loss of coolant and also if a fire is started within the reactor. The Japanese incident is due to a loss of coolant and is known as a \’loss of coolant accident\’ (LOCA). The coolant is usually deionized water, an inert gas or liquid sodium.
The famous \’Three Mile Island\’ accident in 1979 was due to a combination of factors all of which led to core damage, while at Chernobyl in 1986 operator error or a faulty shutdown system led to overheating and the rapid conversion of the coolant into steam. This subsequently led to overpressure within the reactor pressure vessel and an explosion. Luckily the lower part of the reactor remained intact but the fuel rods melted and flowed into the basement of the containment building where it congealed into a solid mass of melted reactor fuel which was subsequently dubbed \’the elephants foot\’. There have been other meltdowns around the world, including at Sellafield (then called Windscale) in northern England in 1957.
When the earthquake hit in Japan, control rods were activated in order to stop power generation, however the cooling system failed, the water inside the reactor stopped circulating and began to boil turning into steam. When all the water had boiled away, the rods, exposed to air, began to heat even more which melted their castings made from zirconium alloy. The alloy reacted with the steam thereby creating volatile hydrogen gas. Despite the attempts by engineers to vent the hydrogen, it exploded which blew the roof off the outer building. The latest plan is to swamp the reactors with sea water to cool them down and also to use boronic acid in order to hamper nuclear reactions.
There are many reasons why nuclear power is a very bad idea, beside the risk of meltdown. To begin with, nuclear power generation is extremely costly.The Florida Power and Light Company for example once estimated the cost of a new reactor plant and arrived at a figure of between $12 and $18 billion dollars, just for one project. It follows therefore that a programme of building numerous nuclear plants would quite easily run into trillions of dollars, which is complete madness in normal times never mind during a recession.
Secondly, nuclear power has been cited as an alternative to middle eastern oil. This suggestion is complete nonsense since we use oil to drive our motor cars and to produce consumer goods not to produce electricity.Furthermore, nuclear power, or rather the fuel it relies upon for generation, will, like oil, peak. A report released by the IAEA in 2001 concluded that uranium supplies could fail to meet demand as early 2026. After that, there is the similar problem to that currently being experienced by the oil industry, new reserves might be discovered but any certainty that they will be will remain entirely speculative.
Leakage of radiation from nuclear power plants is a sever contaminant of groundwater and such leaks have occurred around many nuclear plants in the past. Risks to water supplies are also inherent in the mining of uranium and titanium which the nuclear industry relies upon to fuel its reactors.
Nuclear materials are extremly dangerous throughout the entire process of mining raw materials, processing into energy and storage of waste. The waste is extremely difficult to get rid of and can\’t be contained securely. Selenium 79 for example, which is one of the products of Uranium nuclear fission, will take 327,000 years for half of it it to decay (its \’half-life\’). The radiation emitted by Selenium 79 is minor in terms of its potential to damage human health in comparison to some other materials which are far worse and take just as long to decay.
Nuclear power does nothing to combat climate change. Admittedly a nuclear plant itself does not emit as much carbon pollution as a coal-fired plant, but this is countered by the fact that the entire process of constructing a nuclear plant and mining the fuel for nuclear power generation emits equivalent or perhaps greater levels of carbon.
Exposure to radiation can be deadly. It can induce radiation sickness which can cause nausea and vomiting followed by headaches, diarrhoea and fever. As the level of exposure increases, potentially more serious symptoms such as internal organ failure can follow. Exposure to a level of about four grays will kill about half of all the healthy adults in an exposed population while long term risks can include cancer and genetic mutation.
Nuclear power plants are target No 1 for terrorists. In 2005 for example the Australian authorities arrested 18 Islamic militants for plotting to blow up Australia\’s only nuclear power plant. Meanwhile, the US Nuclear Regulatory Commission has found that more than half of American nuclear plants would fail to prevent an attack on their facilities. The Oxford Research Group has identified various ways in which nuclear is attractive to terrorists. First, theres the risk that they can steal fissile material and turn it into a primitive nuclear bomb. Secondly, they may try to attack a nuclear plant. Terrorists could also target the tanks at Sellafield which hold high level nuclear waste and they could also attack plutonium storage facilities which are dotted around the UK. They could also attack transportation carrying nuclear material in transit. In a report to the Parliamentary Environmental Audit Committee in 2005 the Oxford Research Group estimated that the explosion at Chernobyl released about 4% the amount of radiation that would be emitted as a result of an attack on the cooling towers at Sellafield.
Finally there is the issue of time. Scientists have already concluded that we have 10 to 12 years at best before we start to run the risk of runaway climate change. It takes at least ten years to construct just a single nuclear power plant. Nuclear only supplies around 3.6% of UK electricity and as explained above, the process of supplying fuel and constructing power plants does emit carbon.
It is clear therefore relying on nuclear to solve our energy problems is flawed at best, and may possibly be even an insane idea for all the reasons outlined above.
It is time to ditch nuclear as a mad and dangerous relic of a misguided past.
Bellingham Herald Tuesday March 15th 2011
BBC News Online
Green Energy Works: UK Green Party website.