Napoleon Sarko added nuclear troubles to his problems. Three workers have died after an explosion at a nuclear site in Southern France. The Centraco site is a nuclear waste treatment center north of Avignon. Ten other people were injured in the explosion. An investigation has been opened to determine the exact cause of the blast of an oven used to melt radioactive metallic waste. Nuclear energy accounts for as much as 80 percent of electricity production in France.
Following the Japanese reactor crisis in March, Fourth Reich leaders agreed to run stress tests on how their nuclear power plants would withstand earthquakes, flooding or terrorist attacks, and pledged to make the results public. But Sarko refused to shut down any French reactor. The International Atomic Energy Agency said it is now in close contact with French authorities.
Hoi polloi fear that a nuclear reactor might become an atomic bomb. But this is impossible. Reactor grade uranium is 5% U-235 that produces slow chain reaction. In order to get to bomb grade uranium, the kind that will explode with an instantaneous chain reaction, uranium must be enriched to 90% U-235. http://venitism.blogspot.com
With energy prices so high, nuclear reactors bring windfall profits! On the other hand, a reactor can melt down. This is what happened at Three Mile Island. A valve stuck open and a series of mistakes led the operators to think the core was overflowing when it was actually short of cooling water. They further drained the core and about a third of the core melted from the excess heat. Americans were at shock and awe, because they were not sure what was happening. At the end, the melted fuel stayed within the reactor vessel.
Critics had predicted a China syndrome where the molten core would melt down into the earth where it would hit groundwater, causing a steam explosion that would spray radioactive material across a huge area. Three Mile Island was an industrial accident, but no one was injured. This was not the case at Chernobyl, where a cheap Soviet design did not provide a concrete containment structure around the reactor vessel. A stupid mistake set fire to the carbon moderator, which controls the flow of neutrons. The result was a four-day fire that spewed radioactive debris around the world. More fallout fell on Harrisburg, Pennsylvania, from Chernobyl than from Three Mile Island! http://venitism.blogspot.com
Nuclear power is risky for investors, because it ties up more capital for longer periods of time than its main competitor, natural-gas-fired generation. Nuclear power makes economic sense only if natural gas prices are very high. Then, over time, the high initial costs of nuclear power would be offset by nuclear power's lower fuel costs. Renewable energies should supply half of all energy needs by 2050 and that nuclear and coal power would continue until supplies could be met entirely by clean energy.
Western nuclear reactors are 100% safe, but not the Eastern nuclear reactors. With the earthquake aftermath focusing on Fukushima power plant and possible worst-case scenarios, the question of safety in nuclear energy has returned to the forefront of many people's minds around the world. Japanese Prime Minister Naoto Kan recently announced that his government will be starting from scratch with its energy plans and the country's reliance on nuclear power following the crisis.
The Fukushima reactor has long held the potential for an incident of this nature, being an old power plant with a flawed design, which doesn't reflect contemporary nuclear capability. The safety standards that these old reactors were built to are nothing like today's standards. Fukushima is the second oldest Boiling Water Reactor (BWR) in the world, completed in 1971. Some of these early models have a weak design. At the very time you need the containment facility to protect you, when the core is overheating, you have to vent pressure and consequently possible radiation to prevent explosion.
The earthquake didn't damage the reactors themselves, but did take out mains electricity. The ensuing tsunami knocked out the diesel generators and other back-up systems that were used to pump water around the core, keeping it cool. Once that power failed, the core overheated and was critically damaged a mere 26 hours after the tidal wave hit.
Common cause is the initiating event which triggers a domino effect that inevitably leads to core damage. In this case, tsunami hits, grid goes down, batteries fail, cooling pump stops, core damage results. You can't have a reactor which destroys itself within 26 hours when all you need to do is pump water in – this is unacceptable. More batteries, more diverse pumping systems, whatever the cost. If all you have to do is get water into the reactor and heat out, then that's what you've got to do!
Nuclear engineering has come a long way since the construction of the Fukushima plant. Modern reactor design has focused on the threat from external hazards during the last 20 years: Earthquake, terrorism, plane crash, flooding, and so on. Safety systems, such as the pump and generators that went down at Fukushima, are now built to the same robust standards as the reactors, preventing the potential for a common cause cascade of failure.
When the Fukushima plant was built forty years ago, core damage frequency was predicted as once in every 1,000 reactor years. Following the meltdown at Three Mile Island in the US in 1979, reactors were modified to reduce the likelihood of core damage to at least one in 10,000 years.
The trend has continued to increase dramatically. Plants from the 80's and 90's such as Sizewell in the UK have an expected core damage of once every 100,000 years, and the new generation of nuclear plants are being built to once every 1 million years, as good as we can do. Japan is home to the first 3rd generation advanced reactors, which have been operating since 1996.
But this still leaves the question of what to do with old reactors such as Fukushima, and how to address the worldwide perception of nuclear power following coverage of such disasters in a media-saturated age, which tap into the public fear of nuclear radiation still prevalent from the Cold War and tragedies like Chernobyl.
For Japan, a heavily industrialised island nation with very little natural energy resources, there are no easy answers. The Japanese committed to nuclear power because they had no other option. Post-Fukushima, all they can do in the short term is import gas and fossil fuels. The only way they'll reassure the public about nuclear energy is if they don't care about past energy policy, and they need to look at everything on its merits right now as they stand.
This openness in communication to the public from governments and the nuclear industry is crucial, on a local and global level. In nuclear, what happens in one country affects everyone else. The Japanese haven't yet been open enough with the global community; they need to get more international people involved. The industry needs to be seen to be learning from this, the only way we can progress effectively is by being open and responsive.
Fukushima is a thorny problem, but this is not the time to shy away from these issues. As an industry, nuclear engineers need to learn from this and make things substantially better, not just a little bit better. They learned a hell of a lot about operating and designing reactors from Three Mile Island. The game is to learn from accidents – making these so remote that the public can trust nuclear to generate the energy we need. You don't live without risk. The question is what you do about it in these situations. You either give up or you tackle things and make progress. http://venitism.blogspot.com
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