

A nuclear reactor produces both energy and neutrons. With the right conditions, those neutrons can be used to produce new isotopes.
In a thorium reactor, 232Th absorbs a neutron to become 233Th. This has a 22 minute half life, decaying to 233Pa, which itself has a 27 day half life, decaying to 233U. 233U is fissile and can be used as fuel for the reactor.
235U is also fissile and can be used for fuel, but this is generally obtained by processing natural uranium to select the <1% of the material that’s 233U. This process is called enrichment.
Plutonium breeder reactors make 239Pu by irradiating 238U to capture a neutron. This undergoes a similar decay process as in the thorium fuel cycle: 239U -> 239Np -> 239Pu.

I want to push back on this - quantum entanglement cannot be used to transmit information faster than the speed of light. The entanglement effect does allow for instantaneous correlations, but you can’t use those correlations to transmit information on their own.
For example, imagine Alice and Bob have a pair of entangled particles. The spins are anti-correlated, so if one is spin up the other is spin down. Alice measures the spin of her particle and sees its spin up. She now knows that Bob’s is spin down. She can learn this even if he is many light years away, without needing to communicate with him.
But what information was sent? If Alice or Bob wanted to communicate a simple “yes or no” to each other, how does knowing the spin of each others particles help?
What could happen is Alice and Bob could agree that spin up is yes, down is no. And Alice could measure her particles spin, then call Bob and say “my answer is the spin of your particle” to communicate “no”. This would be physically secure encryption of her answer which is a big advantage, but it is still communicated at classical speeds.
Actually methods of quantum cryptography are more complicated and involve measuring many entangled particles to prove that no one is intercepting the information.