2017 - A year of meltdown-proof nuclear reactor

[Plazma Inferno!]

2017 will be a year of the Rooster, according to Chinese calendar. But it could also be a year of the first meltdown-proof nuclear reactor in the world.
China’s Nuclear Engineering Construction Corporation plans to start up a high-temperature, gas-cooled pebble-bed nuclear plant next year in Shandong province, south of Beijing. The twin 105-megawatt reactors—so-called Generation IV reactors that would be immune to meltdown—would be the first of their type built at commercial scale in the world. Plan is that the reactors go critical in November 2017.

https://www.technologyreview.com/s/...e-a-meltdown-proof-nuclear-reactor-next-year/

 

[Edont Knoff]

The tricky part in there is to keep the pebbles (and their coating) intact and avoid them to become stuck. But the concept is great, the gas-cooled variants even have a higher efficiency than the water-cooled reactors.

Germany once had a reactor of similar type for research and development, but if I remember correctly the pebbles several times got stuck and some broke, releasing radioactive contents into the cooling system.

https://en.wikipedia.org/wiki/AVR_reactor

Well, this is an old story by now. And even that the ruin of that reactor is very hard to clean up (they expect to need 60 more years for it), I always found this concept to be very interesting. The higher temperature allows some other uses as well, using the reactor as a heat source for metallurgy and chemistry, thus saving fossil fuels, and reducing the CO2 production. Using the heat directly for industrial processes boosts the efficiency further, the production of electricity from heat sources is always limited in efficiency.

It is a particularly clean heat if the cooling gas is helium or another inert gas, which makes it even more useful compared to high temperature gases produced with flames. A pity that the best reactors were limited to a little below 1000°C so far, but rising that will require quite different materials for construction, above that, the range where steel begins to soften begins.

A ceramic core, producing ~2000°C would help tremendously in high quality alloy production and also many chemical processes.

PS: Chinese calendar year 2017 element is fire - very fitting

 

[Edont Knoff]

https://www.technologyreview.com/s/...e-a-meltdown-proof-nuclear-reactor-next-year/

[QUOTE]
Several other advanced-reactor projects are under way in China, including work on a molten-salt reactor fueled by thorium rather than uranium (a collaboration with Oak Ridge National Laboratory, where the technology originated in the 1960s), a traveling-wave reactor (in collaboration with TerraPower, the startup funded by Bill Gates), and a sodium-cooled fast reactor being built by the Chinese Institute for Atomic Energy
[/QUOTE]

Wow. The world talks, China does.

A molten salt reactor sure is very intersting as well, and might have similar advantages as the pepple pile type - the ability to produce very high working temperatures. Just the molten salt is way more difficult to handle than inert gases, but even safer, since the natural state (earth surface temperatures) is solid, and so it won't travel far, as opposed to gases, even conceal all sort of nuclear waste from a broken reactor core in a safe way (depending on the salt used. But there are quite neutral, almost inert salts). At least for a while, giving emergency teams time to find solutions how to deal with an damaged reactor.

The sodium cooled variant deems me highly dangerous though. Sodium catches fire if getting wet, hot sodium will burn instantly when in contact with air, the smoke from buring sodium is very dangerous to human lungs (and also skin, not to mention the eyes). Still it is a good cooling agent, and a breeder reactor solves the need to mine more and more uranium ore. Fast neutrons also have applications in technology and medicine, so even that this is not a particularly safe reactor variant, it is a very interesting one.