The frightening effects of the Japanese earthquake and tsunami on that country’s nuclear plants has renewed the debate over the safety of nuclear power. I’ve heard from some people who know something about nuclear power, and here’s what they’re saying.
Quick disclaimer. All of these guys are definitely pro-nuke.
One of them, futurist and trained scientist David Brin, wrote an essay in which he blames the harrowing damage to nuclear reactors to the incompetence of the company in charge.
“The negligence of the operating company – Tokyo Power, which has been cited for violations frequently in the past – is appalling!” he wrote.
Brin said the central problem rose from a series of failures following the tsunami that should have been anticipated.
“The tsunami easily overcame the sea walls surrounding the Fukushima plant. It swamped the diesel generators, which were placed in a low-lying area, apparently because of the misplaced confidence the sea walls would protect them… This was so avoidable,” he said.
Was Homer Simpson running Japan’s nuclear operation?
I spoke with two San Diego engineers with a focus on nuclear power. Ken Schultz is nuclear engineer for General Atomics and George Tynan is a professor of engineering science at UCSD.
Neither of them was as eager as Brin to lay the blame at the feet of Japanese operators. They agreed that the problems were partly due to outdated technology. Tynan also suggested the Japanese may have lacked the imagination you’d need to anticipate the perfect storm of natural disasters that Japan saw a week ago.
“It does look like they didn’t think of the possibility of combined disasters. All those things together; power loss, earthquake and tsunami,” he said. “But can you ever anticipate every possible curveball that nature can throw at you?”
Schultz said that hindsight is 20-20 and, in hindsight, the Japanese should have been better prepared. “But,” he said, “the plant was built to withstand the greatest earthquake Japan they’d ever had in Japan, and what came was four times larger.”
Passive Safety
One major problem with the Japanese reactors is they were built about 40 years ago. They reflected the technology and the safety approach of the time, which involved backup systems and backups to backups to keep the energy on and to keep the water pumps working, to cool the plant, in case of disaster. But what do you do when all of the generation systems fail, the fuel rods are burning up and meltdown is a threat?
Schultz and Tynan said there is a new technological answer to that question and it’s called “passive safety." Tynan said the idea is to design a plant in which it is physically impossible for a meltdown to occur.
Schultz said his company, General Atomics, has designed a completely passive safety system in which the plant shuts down automatically if coolant stops flowing and temperatures reach a certain level.
“So if you’re running along and something goes wrong, you just take your hands off the steering wheel, you coast to the curb and stop,” he said.
I should point out here that General Atomics has yet to apply its new engineering strategy to a power plant in the real world.
Schultz adds that other passive systems cool overheating plants with a supply of water that flows to the reactor core by using gravity, not power. The system is even able to re-condense steam that rises from the plant, so the water can be recycled and flow to the reactor once more.
The future of nukes
“I don’t think we humans have much alternative than to use nuclear power, given all of our needs and demands,” said Shultz.
Tynan agreed and added a climate change warning.
“If you talk to the climate scientists, (our energy supply) has to be 80 percent non-fossil by 2050,” he said. “And you can’t do that without nuclear energy.”
Insuring the safety of America’s nuclear plants lies with the Nuclear Regulatory Commission. A report, just out, from the Union of Concerned Scientists gave the NRC a mixed review. In some cases it was persistence and aggressive at rooting out dangerous safety practices at nuclear plants. In some cases they let stuff slide.
The Japan situations shows that you’ve got to imagine the worst and prepare for it. Let’s hope that’s the future of nuclear power, as global warming forces us to re-imagine our entire system of energy use.
