In terms of priorities it doesn't make any sense at all to me though. It's hard to get the global population to care and act about what the GLOBAL state of the planet will be by the end of the century. So I really could not care less if by accident a few people dug a hole in tens of thousand of years at the wrong place and it created an issue. It's not like the whole human population would meet at this same spot and quickly dig a hole deep enough together so that they all get radiated...
Also, if you do decide to leave a message anyway, you'll just have to make it interpretable to a human, not to any possible "creature". 10 000 years is nothing on evolutionary time scales, so it will still just be us humans around, (or nobody at all, if we happen to go extinct first).
As it is, even with that subsidy financing plants is basically impossible without more subsidies. Bill Gates' new reactor startup required taxpayers to fund 50% of it to even exist.
All solved issues - nuclear energy is a matter of political will at this point.