Russia Unveils Detailed Plans To Build 21 New Nuclear Power Units By 2030

[FBaggins]

13. Do you really not get it?

How exactly are the highly unstable atoms that are the source of the radioactivity suddenly rendered radioactively stable?

Who said that they are? The most "unstable" elements (that is... the ones with the most activity) a seperated from the rest. See your next error.

The point of reprocessing is to remove some of the most unstable and long lived isotopes

Those are contradictory cases. Try again please.

then concentrate and immobilise them in a matrix that can be "safely" stored

Well... no actually. The point of reprocessing is to recover usable fissile material to use as fuel, and then break out the bulk of the material that is not the "most unstable" (because that's easy to deal with)... leaving a small amount of the dangerous waste. Then some paths involve trying to immobilise that remaining waste... but most of the goal of reprocessing is achieved even if they never do that. Far less waste needing storage and fuel available for the next cycle.

As to reactors lasting for decades you will be aware that all reactors have problems with metal failure, both welds and bulk metal, due to the high levels of radioactivity altering the structure of the metal itself.

Actually... I'd bet that she knows a great deal more about it than you appear to. Neutron embrittlement is reversible and is certainly not a problem for all parts of a reactor.

You will also be aware that the pumps and turbines of all power stations have to be replaced at regular intervals because because they cannot be guaranteed to work for decades.

That's a normal part of plant maintenance and is assumed in the longer lifespan estimates.