A few weeks ago, smart alecks opined that as the radioactive dust settled on the recent Japanese tsunami and earthquake, it was time to reassess the role of nuclear energy in generating power. The reality is that nuclear power isn’t going away. China now has 13 operating reactors and another 27 under construction. India operates 20 reactors, has four under construction, and plans to build 20 more. South Korea has seven reactors either planned or under construction. And the list goes on.
As troubling as events in Japan may be, it’s unlikely they will cause a change of heart about nuclear energy in countries that need reliable electrical power. There are simply no existing alternatives for supplying base-load power — that needed to meet minimum customer demands — other than coal or natural gas, both of which are environmentally and logistically problematic. The intermittent nature of renewable sources make them impractical for supplying base-load power.
And Japan’s nuclear problems aren’t so much an argument for other forms of energy as they are an illustration of why the nuclear industry has evolved away from 1960s-era reactor designs. The GE-Hitachi reactors at the source of the difficulties have been upgraded continually, but their fundamental engineering took place over 40 years ago. As the world found out after the Japanese tsunami, the cooling systems on those reactors depend on electrically powered pumps: No electricity, no reactor cooling.
The modular reactors on the drawing boards today avoid such weak points. Examples include the thorium reactor we covered last year and the travelingwave reactor from TerraPower LLC, which we profiled in our recent future technology issue. As explained by TerraPower CEO John Gilleland, “We’ve done tests on a traveling wave reactor where we’ve completely shut off the cooling. You can see the temperature rise only very slowly because there is so much thermal inertia. This is unlike some kinds of reactors where you only have a minute or two to take action. There have also been experiments at the full-scale test facility in Washington state which involved stopping the flow of coolant. Negative temperature coefficients just caused the reactor to shut down.”
As we pointed out in our article, it is unlikely the first traveling-wave or any other modular reactor will be built on U. S. soil. “There is no urgency for this in the U. S., and though the Nuclear Regulatory Commission is a very competent organization, they are not funded to handle advanced reactors (such as the traveling-wave type),” says Gilleland.
We learned from the nuclear problems in Japan that even some of the oldest nuclear-containment structures can withstand one of the largest earthquakes in recorded history. But another lesson is that the time has come to amp up our efforts directed toward advanced nuclear technology. The faster the world moves to advanced reactor designs, the more quickly reactor makers can avoid such wisecracks as appeared on Japanese blogs recently, referring to the U. S.- designed Fukushima Daiichi reactors as the third nuclear attack on Japan.
— Leland Teschler, Editor
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