Slashdot Mirror
Japan's Last Nuclear Reactor Shuts Down
AmiMoJo writes "Japan's last active reactor is shutting down today, leaving the country without nuclear energy for the first time since 1970. All 50 commercial reactors in the country are now offline. 19 have completed stress tests but there is little prospect of them being restarted due to heavy opposition from local governments. Meanwhile activists in Tokyo celebrated the shutdown and asked the government to admit that nuclear power was no longer needed in Japan and to concentrate on safety. If this summer turns out to be as hot as 2010 some areas could be asked to make 15% power savings to avoid shortages, while other areas will be unaffected due to savings already made."
According to this Fukushima 4's fuel was removed soon after the disaster and therefore has been shut down for some time.
The activists have a point. The reactor designs are relatively unsafe compared to modern designs, though it took a hell of a lot of punishment to show it.
Here's hoping Japan makes the switch to thorium.
Except the Activist are against the building of newer safer designs.
This comment is very far off.
Unlike molten salt reactors, a class of fast breeders utilize liquid sodium, which reacts violently with water- and has been a bit of a problem (very costly) when heat-exchangers, reheaters, and similar equipment fails.
Molten salt reactors, like the one prototyped at Oak Ridge National Laboratories back in the 60s, ran for years. The corrosion issue stems from the inadvertent production of tritium (from an undesired isotope of lithium in some formulations of the salt) which can combine with the fluorine (Liquid Fluoride Thorium Reactor/LFTR) to produce a strong acid. These and other problems appear to have very viable solutions (from listening to the relevant scientists and engineers), and should not be used to disparage the technology.
To compare this fission technology that has already been demonstrated in principle with a prototype, to fusion which has not even achieved break-even demonstrates a serious lack of understanding of the issues involved. The primary advantages of the molten salt reactor to energy production are the following:
- based on fission which is a well-understood phenomena; U-233 liquid-fueled reactor already demonstrated in principle decades ago (found to be very reliable)
- a liquid fuel system that operates at low pressure and high temperature which allows for very high levels of safety and efficiency
- the above which contribute to the high likelihood of low-cost reactors
- low cost reactors will dramatically lower the cost of carbon-free energy
- high temperatures allow for more efficient cogeneration; example: ammonia synthesis which could be used as an energy carrier on the scale of petroleum, which would address both concerns about fuel supply and carbon emissions
- high temperatures also allow for the use of dry cooling (as opposed to "wet" cooling which uses a lot of water), necessary for an efficient thermodynamic cycle
- thorium fuel is about as abundant as lead (3-4 times more abundant as uranium), and so very low cost
- fissile startup requirements are minimal (less than a tonne of 20% enriched U-235 is possible)
- system is very proliferation resistant (lots of technical details in the specifics)
The disadvantages:
- we must face our fear of nuclear energy
- more R&D (substantially less than $10 billion) will be required before this technology is a commercial reality
- bureaucratic and industry resistance to a new technology (they've already committed themselves to something else which is not suited for solving our systemic problems)
- the general public remains woefully ignorant of the risks it is facing by foregoing nuclear energy
The potential is that we have a nuclear system that is so safe and efficient that it may have the convenience, but at lower cost, than modern and ubiquitous natural gas plants. We are looking at perhaps the greatest technology humanity has ever developed, at best critical to our transition to a sustainable existence, and at worst, an essential technological step to reduce the risk we currently face. The United States may lack the technical leadership to step into a new era of low-cost carbon-free energy, but its rivals are seriously looking at this approach (China is apparently putting around $100 million annually into this), and if it proves viable on a commercial scale (all signs so far showing absolutely "yes"), the US will be left behind. It is difficult to overstate the importance of this issue to national security. Our economic well-being is dependent upon the cost and convenience of energy, and "farming" low-density energy sources dramatically increases our risk in this area. Lower the cost of energy and you will facilitate wealth creation, otherwise we face recession and decline.
They want modern clean technology like wind and geothermal.
Instead of just guessing what they want why not try simply listening to them.
Though, I'm not originally from here, I live in Japan. You have absolutely no idea what you are talking about.
I talk to Japanese people every day. They are against nuclear power. At best, people don't mind wind power. At least most people don't actively complain about the new windmills being put up (and there are a lot going up). But nobody is calling for them as far as I can tell. But people here do NOT want geothermal. There is a fear that it will somehow destroy the onsens (hot springs). This is a major problem, because we have *no* domestic base load generation capacity except geothermal. Even now, as far as I can tell, there is *no* move to find new geothermal wells.
There is, unfortunately, a media fuelled misconception that solar power will solve all the problems. Granted, where I live, it is quite feasible to run most of your house on solar power. But we still need base load generation and we don't have it.
Don't get me wrong. As far as I'm concerned, nuclear was only a stop gap for Japan. It gave us some time to sort out new technologies. It's not like Japan has a domestic supply of nuclear fuel. But by shutting down all the reactors, it really puts the pinch on. I just hope we end up going the right direction in the end...