By Mark Halper
Posting in Architecture
Uranium fueled, water cooled reactors won the day in the Cold War over safer alternatives like thorium and others that could still do to Big Nuclear what the Internet did to Big Telco and Media.
Today is the one-year anniversary of the earthquake and tsunami that tragically killed an estimated 19,000 people, wiped out entire towns and led to meltdowns at the Fukushima Daichii nuclear power station in northeast Japan.
Japan has subsequently shut down almost all of its 54 nuclear reactors, an understandable short term reaction but also one with considerable energy and economic consequences given that nuclear had supplied 30 percent of Japan's electricity.
The Fukushima Daichii plant melted down because it used an old-fashioned system that relied on external power to operate its reactors' cooling system. The backup in that system failed when the tsunami flattened the diesel generators that drove it.
The anniversary thus marks an obvious time to reflect on nuclear. The nuclear choice is not black and white. It's not a simple "yes" or "no" decision. Rather, it's a matter of "yes but." What the world should do is stick with nuclear as part of its CO2-light mix of energy generation, but move away from the conventional water-cooled, uranium fueled reactors that comprise nearly all of the 435 reactors that the World Nuclear Association says are operating on the planet today.
Granted, many, maybe even most of those 435 are not as prone to failure as was Fukushima. And the Big 3 reactor makers - Toshiba Westinghouse, GEH and Areva - are indeed moving toward safer designs that deploy "passive cooling" systems that do no rely on external power. But those improvements are bolt-ons to the basic water-cooled, uranium fueled design that took root in the 1960s, when the weapons-grade spent fuel that they produced appealed to the U.S. and the Soviet Union, two countries then caught up in a Cold War and intent on nuclear armament.
Here, is a quick look at alternative fuels and designs that would support a safer nuclear future, from the standpoint of both operational safety and weapons-grade waste. These technologies could be the same sort of disruptive force to Big Nuclear as the Skypes and Googles have been to Big Telecom and Media. They are the Betamax to the inferior VHS of conventional nuclear. Unlike Betamax, they should find longevity. They have been around for decades. In a back to the future play, now is their time. China is developing all of them. This is not a complete list, nor a thorough examination of each. For that, I could point you to my Kachan & Co. report, Emerging Nuclear Innovations - Picking global winners in a race to reinvent nuclear energy. Consider the following a good taster, and a handy pocket guide, of alternative nuclear:
Thorium. An alternative fuel to uranium. It's abundant. Its waste has little of the weapons proliferation risk associated with uranium and lasts for only hundreds of years, not the tens of thousands (or millions) associated with uranium. Deployable in conventional reactor designs. Some supporters like Kirk Sorensen, president of Huntsville, Ala.-based thorium reactor startup company Flibe Energy, believe that thorium operates best in a reactor design known as molten salt (see below). Oak Ridge National Laboratory built a molten salt thorium reactor in the 1960s, which could have become the industry standard had the U.S. government not settled on more weapons-friendly uranium during the Cold War. Thorium developers in China include a group called INET at Tsinghua University, and the China Academy of Sciences.
Molten Salt Reactors. MSRs use liquid (molten) fuel, not the solid fuel rods of today's reactors. This provides cooling advantages, because the coolant can travel with the fuel in a molten salt mix, reducing engineering of cooling system. MSRs tend to require less fuel, and less fuel enrichment. Flibe Energy and Ottawa Valley Research are working on MSRs.
Fast Neutron Reactors. Unlike conventional reactors, FNRs allow neutrons to travel fast through the reaction chamber. This potentially increases the efficiency of fuel, and increases what the industry calls fuel "burn-up." Fuel lasts much longer in an FNR than it does in a conventional reactors. FNRs can also tap, as fuel, the plutonium and long-lived "actinides" that today's reactors leave as dangerous, weapons-grade waste. The plutonium "breeder" reactor is a form of FNR, but FNRs do not have to be breeders (breeders produce more plutonium than they consume). Demonstrator FNRs have encountered various accidents, but when built and operated correctly, FNRs hold great potential. In theory they can run for 30 years or more without refueling; today's uranium rods last about 18 months. TerraPower, the Bill Gates-backed nuclear startup, is developing at type of FNR known as a traveling wave reactor. General Atomics in San Diego has a rival FNR design it calls the energy multiplier module, which can use spent fuel from other reactors. China plans to shift heavily to FNRs by 2050.
Pebble Bed Reactors. PBRs are a form of gas-cooled reactors. Gas picks up heat emitted by reactions in balls, or pebbles, of fuel. The gas runs through a heat exchanger to boil water, create steam and drive a turbine. QPower, a South African company, is investigating the use of helium as the coolant, and believes this will be far safer than today's water coolant. China is planning close to 20 PBRs.
Fusion. This has been the Holy Grail of nuclear power since at least the 1950s. It gave rise to the atomic energy catchphrase "too cheap to meter." Whereas conventional nuclear and all the alternatives above practice the fission of splitting atoms apart, fusion gets energy from putting atoms together. Typical development projects aim to fuse two isotopes of hydrogen - deuterium and tritium. Another type fuses standard hydrogen and boron. The great challenge of fusion is to get more energy out of the process than what goes in - and there has to be enough of an excess to be financially viable. Some of the best known fusion research projects are huge, expensive, international, government backed operations, such as the ITER tokamak in Cadarache, France, and the laser-based National Ignition Facility at Lawrence Livermore National Laboratory in California. They are still decades away from commercialization. But several startups include General Fusion, Helion Energy and Tri-Alpha could get there much sooner.
All of these technologies face an uphill battle against the entrenched powers of the water-cooled, uranium industry. They also face regulatory hurdles. Regulators like the Nuclear Regulatory Commission in the U.S. would take at least seven expensive years to approve the commercial deployment of a new fuel or reactor type. But that could speed up. When I last looked, President Obama's Blue Ribbon Commission on America's Nuclear Future was considering splitting the NRC so that a separate group would examine alternatives and expedite a sound review process. It's time to split from the past, and make that happen. It could help fuse a safe nuclear future.
Note: This version corrects an earlier version, which referred to the fusion company General Fusion as Nuclear Fusion. Apologies for the error. -- MH. (March 13, 4:15 a.m. PT)
Kirk Sorensen photo from Kirk Sorensen.
More from the Collateral Damage series:
- The plastic legacy of Great East Japan tsunami debris
- Q&A: Hitoshi Abe on design lessons from the Great East Japan earthquake
- Listen to Japan's 9.0 earthquake
- Asian Super Grid: How Japan's anti-nuclear plan could go nuclear
- A year after Fukushima, how life in Japan has changed
- In post-Japan quake & tsunami era, Noah offers emergency shelter
More nuclear options:
- Watch replay of nuclear's future, with dash of rare earth, political intrigue
- Why safe nuclear will rely on rare earth minerals
- Meet the future of nuclear power: 8 guys in China
- The new face of safe nuclear
- Emerging Nuclear Innovations - Picking global winners in a race to reinvent nuclear energy
Mar 10, 2012
U can use nuck??lear energy without the risks of nuclear power plants. Most of the heat in the earth comes from radioactive decay. This heat can be used in geothermal power plants. You don't need nuclear power plants any more, if you use renewable energies, including geothermal!
I see that nuclear is gaining a bit more traction lately - or maybe the publicity is being built up to generate a perception of new respectability for nuclear. I am unconvinced, at this time anyway, that any nuclear is safe, whether it be thorium, uranium or waste material. At this time I believe it is correct to say that the technology is still short of what is needed. I am concerned that nuclear is so easily portrayed as a "fix" for our energy issues. Fully deployed, it will certainly reduce our need for fossil-fuelled power generation - but if the lead time for say a "new" reactor is 15-20 years, wide scale deployment of the new reactors will take years. I was told once (sorry no source) that right now we would need ~100,000 nuclear reactors to totally displace coal. Sound a lot, and since I don't have a source, let's just say we need half that number. How many can we build per year? Can we build enough to slow down carbon dioxide sufficiently? I have my doubts. And if I am right, that logistically we are too late, nuclear is not a fix. We are betting on technology that has yet to be proven, so don't relax yet.
I believe the half-life of Harry Reid and his puppet Jackzo is much shorter than the half-life of the fission products, and even of the Yucca Mtn project, even though we are not happy to be manipulated like that.
Minor detail: fission adds a particle to an atom that makes it unstable and causes it to split into two or more smaller atoms (e.g. U235 + neutron ==> U236* (*=excess energy) ==>fissions Kr90 + Cs139 + 2.4 neutrons). Fusion takes two smaller atoms and makes at least one larger atom, but often a smaller particle comes out too (e.g. H2 + H3 ==> He4 + n) . For p-B11, it is H1 + B11 ==> C12* ==> Be8* + He4 ==> 3He4, so B11 is like U235 and C12* is like U236*, and 3He4's are all smaller than the original B11. The reasons this tends to be called fusion is that you need a fusion like reactor to get the two charged particles together (like fusion), and there is no self-sustaining reactions from excess neutrons, like most fission reactions. There might even be some desire to keep p-B11 separate from fission because of the bad connotation of fission as dangerous, and fusion as clean.
We have these different types of power plants, why not take away (I don't think you can just pull the plug though, lots of people will be affected since Big Oil will try and cut off expenses to maintain the high level of profit) all of the subsidies from oil and other destructive practices and funnel them into safer alternatives. People think that renewables is only limited to what my friend jokingly calls treehugging power (solar, wind, etc.). People need more education to make more informed decisions. Cheers, great article! Juan Miguel Ruiz GreenJoyment.com
Has anyone come up with the 10,000 year sign warning people (only our species ?), of the dangers we have already created? How can any warning sign communicate the dangers for the next 10.000 years. What language do we use to tell birds, animals, plants, wind, rain to stay away from the danger. Are there any efforts to neutralize our current uranium mess, or do we keep our minds & eyes closed and say "Oh well. - Lets move forward and hope that we can bury our problems for the next 10,000 year?"
The current predominant reactor design did not "take root" because it produced "weapons-grade spent fuel" as stated. The driving force for development of this concept was the nuclear submarine powerplant. The first commercial reactors (and most current reactors) were based on this design. Probably no weapons-grade material has been produced in these plants, but in special-purpose designs whose spent fuel could be removed after fairly short irradiation times.
The hurdles for nuclear power are many, from designs to the permit process. There are a couple of problems that still need to be addressed and those are a long term disposal facility and the decommisioning of old reactors. The current storage of spent fuel and waste has not changed; the Yucca mountain storage facility had problems both physical and political. There are very few alternative storage solutions beyond storing in the cooling tanks. Decommissioning a reactor takes a lot more time and expense than given when the reactor facility is proposed. Decommissioning a reactor is similar in concept to cleaning up asbestos contaminated buildings, both use stringent methods to contain the mess and also deal with the collected wastes. Decommissioning a reactor can take as long as a decade with similar problems with dealing with the radioactive wastes. The alternate nuclear technology may help get all of us through the end of the era of cheap oil. But, there needs to be a good answer to waste disposal and decommissioning.
lynn: One of the main benefits of molten salt reactors is that they will be able consume the long-term nuclear waste from conventional reactors as fuel, while producing only a minuscule amount of waste themselves. If you really hate nuclear waste then you would be clamoring for the roll-out of molten salt reactors. They will convert the waste you love to hate from a 300-century problem into a 300-year problem.