China's nuclear reactor technology achieves breakthrough or will eliminate melting risk
Source: Global Network Date: 2015-11-09
According to a report on the South China Morning Post website on November 4, Chinese scientists are one step closer to being able to operate a nuclear reactor without producing a chain reaction. On the one hand, the risk of melting can be eliminated, and on the other hand, piles of nuclear waste can be removed more quickly and safely.
All reactors today rely on chain reactions, but chain reactions can run out of control and cause a big bang, as happened in the Chernobyl disaster in Ukraine in 1986. Chain reactions also produce large amounts of radioactive waste, which takes millions of years to safely biodegrade.
Xuan reported that the Chinese research team is trying to solve these two problems with a new method, and they are exploring the use of proton beams in subcritical reactors.
Plutonium nuclear scientists have dreamed of building such a reactor for decades, but due to many scientific problems, this has been a theoretical construction so far.
China's research team uses external high-energy proton beams to initiate and maintain the nuclear fission process. As a result, as soon as the proton beam is interrupted, nuclear fuel stops burning. This eliminates the risk of chain reactions, which are currently used in reactors to maintain nuclear fission.
In addition, proton beams can generate neutrons fast enough to consume other fissionable materials, such as plutonium and waste from commercial reactors, after hitting the target. This is known as an important nuclear "waste disposal" measure.
Professor Pan Weimin, chief scientist of the accelerator-driven subcritical clean nuclear energy system (ADS) project of the Institute of High Energy Physics of the Chinese Academy of Sciences, said: "We are very excited. We have solved the problem of starting (reactor) 'engines' directly cold starting." Proton beam generation is likened to starting an old car engine on a cold day, because the difficulties are equal. Once started, it runs smoothly, but completing the initial "ignition takeoff" is not easy.
In order to successfully "start the engine", the Chinese research team successfully conducted an experiment in Beijing this October. According to the information released by the Chinese Academy of Sciences website, technically, they are able to stably accelerate a pulsed proton beam in excess of 10.4 milliamps to 6.05 megaelectron volts. Professor Pan said this meant they could achieve the initial "ignition takeoff" to start the subcritical reactor. This breakthrough cleared a major technical obstacle that prevented the construction of this reactor, which has so far remained on paper. "We built a brand new nuclear 'engine'," he said. "It's not running at full speed, but it's up and running."
Judging from the recent pace of technological development, Professor Pan expressed his confidence in building a new generation of power stations within ten years. But other Chinese researchers claim that his solution may not be the best, because there are other new reactor designs and methods. The concept of subcritical reactor was first proposed by American physicist Ernest Lawrence in the 1950s and attracted worldwide attention with the support of Carlo Rubia, one of the 1984 Nobel Prize winners in physics.
Xun reported that, but it turned out to be a difficult bone. In addition to the challenge of generating a strong and stable proton beam, there are many other structural and mechanical challenges to be overcome.