COMMENT: Martin,
Very long time reader and fan. I’m a physicist, I’ve spent years proving mathematically what you say about local weather change.
It’s apparent that humanity should embrace nuclear fission to switch fossil fuels as they slowly deplete and change into too costly.
Photo voltaic and wind are a joke, and sensible fusion is many a long time away. Sadly, so few folks perceive the physics, {that a} multitude of mis-conceptions cloud this subject, and few even acquired into your publish.
First, Thorium produces roughly the identical energy pound for pound as Uranium or Plutonium. However Thorium IS NOT FUEL, like Uranium 238 it’s FERTILE however not FISSILE: it can not ‘burn’ by itself. Nevertheless, Thorium 232 might be bred into the fissile isotope Uranium 233, which burns identical to Uranium 235. This breeding course of already occurs to Uranium 238 in our present reactors. It absorbs a neutron, and decays into Plutonium 239, which burns even higher than Uranium 235.
All our present reactors depend on enriched Uranium to function, which implies they burn solely 4% of their gasoline. However so-called quick breeder reactors might faucet into this huge provide of fertile isotopes, and breed and burn 100% of the gasoline. Simply burning it up utterly additionally makes the waste vastly much less harmful.
The physics of breeder reactors is well-understood, however we want engineering analysis to excellent a brand new technology of sensible secure breeder reactors. By far probably the most promising expertise is the Molten Salt Reactor, the place the reactor gasoline is a liquid that circulates from the ‘core’ by warmth exchangers, to provide steam like several reactor. It runs at atmospheric stress so it can not endure steam explosions, and if If something goes flawed, the gasoline might be emptied from the reactor by gravity, shutting it down in seconds.
Apparently, the person who developed our present reactors, Alvin Weinberg, instantly noticed how unsafe they had been. So within the 1950’s started creating the Molten Salt reactor. He constructed a number of which labored flawlessly. However the authorities shut his challenge down within the 1970’s. Now could be the time to resurrect his sensible design, and construct a technology of a lot safer, much less cheap and extra environment friendly fission reactors to energy humanity’s future.
REPLY:
Pressurized Heavy Water Reactors (PHWRs) fueled by uranium generate plutonium. That plutonium is then utilized by Deploy Quick Breeder Reactors (FBRs) to create fissile materials resembling uranium-233. The ultimate stage employs the Superior Heavy Water Reactor (AHWR) and different thorium-based fuels which can be designed to function on thorium-plutonium and thorium-uranium-233 blended oxide fuels. Thorium just isn’t gasoline, as one reader identified, however can change into fertile when became uranium-233.
Most present nuclear reactors are mild water reactors (LWRs) that use enriched uranium (usually about 3–5% U-235) as gasoline. These reactors extract lower than 1% of the vitality out there in pure uranium, as they primarily fission U-235 and depart the rather more ample U-238 largely unused. The declare that they burn solely 4% is broadly correct, however the true quantity is a bit nearer to 1% for once-through cycles, and as much as 4-5% for sure fashionable gasoline cycles.
Quick breeder reactors (FBRs) are designed to transform fertile isotopes (like U-238 or Th-232) into fissile isotopes (like Pu-239 or U-233), enabling them to extract practically all of the potential vitality from uranium or thorium. This could theoretically enhance gasoline utilization by an element of 100 in comparison with LWRs. In observe, FBRs can make the most of 60–70% of uranium’s potential vitality, with the rest being fission merchandise and a few unconverted fertile materials. Breeder reactors also can considerably cut back the amount and long-term radiotoxicity of nuclear waste, as most actinides are consumed, leaving primarily shorter-lived fission merchandise.
Alvin Weinberg led the event of the pressurized water reactor (PWR) and pioneered molten salt reactor analysis at Oak Ridge National Laboratory within the Nineteen Fifties and Sixties. The Molten Salt Reactor Experiment (MSRE) operated efficiently however was discontinued within the Nineteen Seventies resulting from shifting priorities and funding.
Alvin Weinberg believed that light-water reactors (LWRs) had been extraordinarily dangerous and recognized points with loss-of-coolant accidents (LOCA), core meltdowns, and containment breaches, in addition to insufficient scaling of containment constructions. The complicated nature added to the danger of human error. “Can we develop nuclear reactors whose security is deterministic, not probabilistic, and which, if developed, would meet the general public’s craving for assurance of security, not merely assurance of the chance of security?” he requested. His proposed reactor makes use of liquid sodium versus water as coolant, permitting the reactor to function at a decrease stress, lowering threat.
Former President John F. Kennedy believed that succeeding in producing a possible molten salt reactor was “very distant” after the US Air Pressure spent $1 billion ($7 billion in the present day) from 1946 to 1961 on the Plane Nuclear Propulsion program. The US authorities could have deserted plans to study molten salt nuclear reactors, however the Canadian, Indonesian, and Chinese language governments have invested tens of thousands and thousands into creating the expertise. None apart from Invoice Gates funded the nuclear enterprise Terrapower that has produced a molten chloride quick reactor, tying this into his local weather change marketing campaign.
China created the primary totally operational thorium molten salt reactor in 2024 and stays the one nation to have efficiently accomplished the challenge. This 12 months, the Chinese language authorities produced a live-refueled reactor and plans to assemble a bigger 10 MW model by 2030. China introduced its thorium discovery one month after scientists introduced their groundbreaking achievement.
So I stand corrected—China just isn’t on its solution to turning into the world’s main nuclear tremendous energy—China IS the world’s main nuclear tremendous energy.
