Re: Would a system to dispose waste by dumping it into the sun be a good idea?

There are some advantages to your proposal.  The chief advantage is that, 
once vaporized in the sun's atmosphere, the nuclear waste would simply 
cease to exist.  And, of course, it would no longer be on Earth to cause 
problems.  Unfortunately, there are some disadvantages to this method that 
make it impractical and unlikely to be used.

The biggest factor is cost.  It costs from tens to hundreds of millions of 
dollars to put a satellite into orbit that weighs a few tons.  It costs 
much more to boost a payload out of orbit because it takes more energy to 
escape the earth's gravity, and we'd be looking at disposing of material 
weighing much more than the proposed space station.  It's unlikely that 
the nuclear power industry or government would be willing to pay so much 
money to dispose of radioactive waste.

The other factor is public opposition to such launches.  Many space probes 
have been launched that use radioactive materials for power.  Every time 
this happens, there are objections and protests by environmental groups, 
even though there is almost no chance of an accident.  I think it is very 
likely that any attempts to dispose of nuclear waste by launching it into 
space would be very strongly opposed by these groups.  Also, we would have 
to make many launches each year, which would make for even more protests.

The bottom line is that, while launching radioactive waste into the sun 
would certainly destroy it, it's likely to be much too expensive to be 
practical, and many people would oppose any such plan.  So, we're just 
going to have to find a place on earth for it!