Oklo's stock has already soared this year, but a long runway for nuclear innovation could mean its story is just getting started.If you're just noticing nuclear stock Oklo (OKLO +4.96%), you might be looking at its year-to-date performance through burning eyes.The stock is up over 450% on the year, putting the company's market cap at about $18 billion. Investors might balk at a stock that's already seen such extraordinary gains, let alone a company like Oklo, which has no revenue and no reactor in operation ...