Energy From Thorium Discussion Forum

A new form of logic:
http://unews.utah.edu/news_releases/radiation-resistant-circuits-from-mechanical-parts/

This logic is much larger and slower than semiconductor electronics. But surely it would be useful in monitoring and controlling the on-line processing of the hot and radioactive reactor salt!

This stuff has no moving parts and IIRC has been in continuous use in high-radiation environments for decades.

My brother designed a series of plastic molds for fluidic logic. This was thirty or more years ago.
They used low-pressure compressed air, and were interconnected by rubber hose.
Indicators were little balls of fluff in transparent tubes.
The technology can do anything electronics does, maybe a bit slower.
I think if it had been discovered in 1820, Babbage might have used it instead of mechanisms.

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

Robots and remote controlled equipment could be in general a big opportunity for nuclear. It could work in high radioactive environments as doing maintenance close to a running reactors, work with contaminated structures (Fukushima) or reprocessing units.

The bad thing is that electronics gets smaller and smaller and even a few neutrons and gamma can disturb it. I woud not wonder if electronics becomes more and more sensitive to the radiation in aircrafts (cosmic radiation) flying in high altitudes.

Fluid logic and mechanical computers are an alternative. The bad thing is that no one else than nuclear and space technology (high cosmic radiation) needs it.

Does anyone know if NASA is working on the topic as well?
Is someone working on electronics resistant to radioactivity?

Solid state circuitry also works when you have transisters the size of the old 80286 or larger. The bigger the feature, the less sensitive. The Japanese have the problem that they are trying to fit VERY capable robots thru very small openings.

_________________
DRJ : Engineer - NAVSEA : (Retired)

Space-rated electronics are well-known. These resist cosmic rays, even solar storms.

They are also garbage compared to newer, less radiation-resistant, electronics.

Space rated CPU's (not necessarily those mixed hard/soft core FPGA rigs) are also around 486 class in terms of capability, due to process size (so gates are more rad hard), and processor design is still in the realm of human verifiable (gate count)

Vacuum-channel transistors are the same size as FETs, resist radiation (they are "tubes", scaled-down) don't need crystalline semiconductors, and run 10x faster.
And also, they don't need plate heaters or hard vacuums.
https://www.nasa.gov/ames-partnerships/technology/technology-opportunity-nanostructure-based-vacuum-channel-transistor

In most cases (certainly for stationary apps) it is more practical to shield the electronics rather than try to harden them.

Cyril, you're totally right. Even in a space-rated reactor, the controls would probably be conventional electronics on the shadow side of a shadow shield. Maybe the structural beam holding the reactor would shield the electronics, too.