TOMSK, October 27. /TASS/. Scientists at Tomsk Polytechnic University (TPU) have found a way to synthesize fuel oxide compositions for high-temperature gas-cooled reactors, making them safe in case of an accident and synthesizing hydrogen left in them, associate professor of the Nuclear Fuel Cycle Department at TPU's Nuclear Engineering School Alexander Karengin told TASS on the sidelines of the "Hydrogen. Technologies. The Future" conference. 

"The development of hydrogen technology is coming to the forefront now. One of the main methods of its production is water electrolysis and steam conversion of methane. However, steam conversion requires huge energy inputs with half of the methane being burned to reach operating temperatures. High-temperature gas-cooled reactors could be the way out. But the nuclear fuel that is currently in use is not suitable for that," Karengin said.

TPU scientists used a grant from the Russian Science Foundation to solve the problem of finding fuel mixtures with the required characteristics. Based on the results of several hundred experiments, they selected the most promising method of fuel creation - one-stage plasma-chemical synthesis in the air plasma flow of fuel oxide compositions from dispersed water-organic nitrate solutions that include an organic component.

It allows fuel synthesis using a plasma flow that hits uranium in a special nitride solution with the addition of organics, particularly alcohol, and metals used as a matrix (e.g., magnesium). This method makes it possible to obtain a relatively inexpensive, but at the same time effective and combustible fuel, which will create the desired temperature in the fuel element without the risk of destruction. Thus, it will be possible to synthesize hydrogen with nuclear reactors.

Need for research

The scientist explained that in a high-temperature reactor with a gas cooling system, a methane-based gas mixture could be used to cool the fuel elements. The methane would be converted to much needed hydrogen under the influence of high temperature. However, a significant portion of nuclear power plants use ceramic pellets with uranium dioxide nuclear fuel or dispersed thorium-uranium fuel. During reactor operation, these fuel elements (fuel pellets) are heated, but due to their structure they do not conduct the temperature well - it reaches the required 1,250 degrees Celsius for fusion inside the pellet, while on the surface it’s only about 400 degrees. If you increase the temperature, the fuel cells will simply melt, so they constantly need to be cooled.

Hydrogen is considered one of the most promising fuels, which, in addition to being highly efficient, is not harmful to the environment. The International Hydrogen Council estimates that by 2050 hydrogen will account for 18% of the world's total energy demand.