The Independent: China unveils meltdown-proof nuclear power plant (Pebble Bed Reactor) in clean energy breakthrough

[OKIsItJustMe]

https://www.independent.co.uk/climate-change/news/china-nuclear-reactor-power-plant-meltdown-proof-b2586374.html

China unveils meltdown-proof nuclear power plant in clean energy breakthrough
Materials used in reactor can withstand very high temperatures without melting

Stuti Mishra 2 days ago (sic)

China has unveiled the world’s first meltdown-proof nuclear power plant, achieving a groundbreaking and potentially transformative feat in the field of nuclear energy.

The plant, developed by researchers at Tsinghua University, represents a major leap forward in nuclear energy safety, which has been under scrutiny since the catastrophic meltdown at the Fukushima nuclear plant in Japan over a decade ago.

…

The new Chinese plant uses an innovative design called a "pebble-bed reactor” to mitigate the risk of meltdown.

Unlike most reactors that use water to cool down, it uses helium gas, which can handle much higher temperatures.

…

Fron concept to reality in just over… ¾’s of a century…

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

… It was in that role, in 1947, that Daniels conceived the pebble bed reactor, a reactor design in which helium rises through fissioning uranium oxide or carbide pebbles, cooling them by carrying away heat for power production. …

[NNadir]

1. The Journalists responsible for this article should really have done their homework.

A "pebble bed" type reactor operated in Germany between 1967 to 1988, the AVR, a relatively small scale reactor, but nonetheless the operable technology is hardly new. The AVR operated on a helium Brayton cycle. The "pebbles" were exactly the same as "modern" pebbles, layered silicon carbide with uranium carbide and graphite.

The thermal expansion of silicon carbide leaves subject to cracking exposing the graphite layers. There is some (minor) risk that the fuel, exposed to air at high temperatures, will burn. It may be "melt proof" but it is not fire proof.

It is absolutely essential that we be able to recycle used nuclear fuels. Doing so with the silicon carbide system will prove, I think, somewhat problematic.

Helium gas is not sustainable. Within several generations, all of the world supply will be obtained from decay of short lived actinides like curium, americium and some isotopes of plutonium. All helium released into the atmosphere ultimately boils off into space, since under normal Maxwell Boltzmann distribution conditions, a significant portion of the atoms, owing to their light weight, exceed the planetary escape velocity.

A more modern, and, I think, more interesting variant of the pebble bed concept does not rely on a gaseous coolant although it can run under Brayton conditions. It is the Kairos reactor, under development in the United States, the Brainchild, more or less of UC Berkeley's Per Petersen. In this case the "pebbles" are immersed in a molten salt (good old FLIBE, if I recall correctly).

The Kairos company recently received approval to build a test reactor at Oak Ridge National Lab.

The worst nuclear reactor, even the graphite moderated RBMK type of which Chernobyl was an example, is safer than the best fossil fuel plant.

The Chinese are serious innovators in nuclear engineering, and in general, I approve of their explorations. This said this reactor type is not new, nor is it necessarily superior to existing reactor technologies. Nuclear power cannot be made "safer" because it is already extraordinarily safe in spite of all the selective attention it draws. No other form of energy on the scale of nuclear has a better safety profile than nuclear energy does. It doesn't need to be risk free to be vastly superior to everything else. It only needs to be vastly superior to everything else, which it is.

In comparison, by the way, to extreme global heating, the much ballyhooed Fukushima is hardly a "catastrophe."

As for the news item, it rather demonstrates that one may be challenged to get a degree (or a job) in journalism if one has passed a college level science course with a grade of C or better.