Source: Science and Technology Daily
In recent years, human beings have become increasingly dependent on energy.However, non-renewable resources such as coal, oil and natural gas are not inexhaustible.Is it possible to solve mankind’s energy shortage once and for all?As nuclear technology matures, controlled nuclear fusion reactors, known as “artificial sun” and “ultimate energy for mankind”, may provide mankind with a steady supply of clean energy for future generations.The principle behind the technology is that deuterium and tritium produce fusion reactions at high temperatures and pressures, and generate large amounts of heat for power generation.
Recently, shenzhen university, professor Chen and zhang wei feldspar team and nuclear group in southwest of nuclear physics research institute, for the first time put forward and realized based on integration of 3 d printing free design and forming complex porous structure is lithium silicate ceramic pieces, is expected to replace traditional microspheres bed structure, become a new generation of tritium production devices, show important application prospect.The results have been published in additive Manufacturing.
The artificial sun is a step closer to the ultimate energy source
Since the discovery of nuclear reaction, people have been exploring the effective use of nuclear energy.Nuclear energy can be released through three nuclear reactions.Among them, nuclear fission refers to the fission of heavier nucleus to release binding energy, such as atomic bomb explosion;Fusion is when lighter nuclei come together to release binding energy, such as in a hydrogen bomb explosion;Nuclear decay is the spontaneous release of energy by the nucleus, which is usually a slow process and of a lower order of magnitude.
Today, controlled nuclear fission is commercially available, with nuclear reactors producing about 16 percent of the world’s electricity and nine countries generating more than 40 percent of their energy.But the safety risks of nuclear power generation remain a lingering shadow.Moreover, the heavy metals such as uranium needed for fission are scarce on Earth, and conventional fission reactors produce highly radioactive nuclear waste.
That’s why a growing number of scientists and energy experts are turning to fusion.Fusion is based primarily on hydrogen isotopes — deuterium and tritium.Deuterium can be obtained in seawater and contains about 30 milligrams per liter of water.A 1,000-megawatt fusion power plant would consume only 304 kilograms of deuterium a year, enough to power humans for billions of years.
However, tritium is almost never found in nature and requires a continuous catalytic reaction between helium and lithium ceramics.As an important component of magnetic confined fusion reactor, solid tritium producing cladding is one of the core problems to be solved before the commercial application of fusion energy.
Currently, the preferred tritium breeder material for scientists around the world is lithium orthosilicate (Li4SiO4). The popular method is to react lithium silicate ceramics with helium to produce tritium.The ceramic components that do this are called tritium producing units.
Conventional tritium producing units of lithium ceramics typically make lithium silicate into microspheres about 1 mm in diameter and pile them up to form a bed structure in which helium can be injected into the Spaces between the spheres.However, the filling rate of the tritium producing unit is limited and cannot be regulated freely.In addition, the stress concentration caused by the stacking of microspheres is easy to cause deformation and cracking of the tritium producing unit structure, which becomes the constraint to the structure and uniform stability of the ball bed.Once the tritium producing unit fails, the fusion reactor cannot run smoothly.So scientists have been trying to optimize the structure of the tritium producing units.