reSee.it - Tweets Saved By @whatisnuclear
@whatisnuclear - Nick Touran
Crazy story: in the early 1990s, the USA purchased 6 TOPAZ-II space nuclear reactors from the USSR/Russia and flew them to New Mexico for testing. These reactors had thermionic cells around each of their 37 fuel pins: "Thermionic Fuel Element"! (a 🧵...) https://t.co/ZedMp9PUFa
@whatisnuclear - Nick Touran
The 115 kWt reactors used 93% enriched annular UO₂ fuel elements, which transferred heat through a cesium gap, converting about 5% of the heat to electricity. Outside each pin, they had electromagnetically-pumped liquid metal sodium-potassium eutectic coolant. https://t.co/wu5X8dIiea
@whatisnuclear - Nick Touran
The pins were dispersed in a ZrH₁.₈₅ moderator. There were beryllium reflectors and beryllium control drums, each with a 116° strip of boron absorber. They had LiH radiation shielding. The reactors consumed 0.5 g of Cesium per day. https://t.co/5Hc5zwaAhF
@whatisnuclear - Nick Touran
In 1989, the TOPAZ lead came to Albuquerque and expressed interest in collaborating with the US. The US's space concept, the SP-100, was over budget and behind schedule, so the TOPAZ could be a good deal. A series of meetings followed. At one, a model of the reactor was shown. https://t.co/EaCQiPjEvB
@whatisnuclear - Nick Touran
On April 26, 1992, a C-141 and a C-130 came to pick up the first reactor. There was some trouble with identifying which of the 80+ crates had hazardous material, and at one point someone had to run to furniture stores to get some foam padding, but they got it loaded. However, the export officer at the St. Petersburg airport would not accept the export license because it had been signed by the USSR, which had in the meanwhile ceased to exist! More meetings were had and eventually a new license was approved. Airplane maintenance and air clearance rights persistent, but eventually the delivery was made! Another deliver of 4 more reactors was made in 1994.
@whatisnuclear - Nick Touran
The US did ground testing and planned to fly them. Ex-Soviet scientists came and helped at the University of New Mexico. Russian language training was provided. In the end, a flight test never happened due to budget constraints and anti-nuclear sentiment, though staff was proud of what they accomplished: "We were able to convince critics and openly hostile groups that NEPSTP could be carried out safely. I believe that the success of our approach will set a valuable standard for all future space reactor missions." I wonder if we can dust these off and fly them now!? (Links to source info and much more in the alt text of image)
@whatisnuclear - Nick Touran
BONUS: when the Soviets tried to take their conference model back out of the USA, the NRC banned it, saying that it would be an export. This was back when the NRC was a true pain in the ass. https://t.co/98cQTqpN7z
