nuka cola quantum
From thar Wasteland Survival Guide:
'In 2077, a new version called Nuka-Cola Quantum was introduced. Accordin' to yonder advertisements, it had twice ye calories, twice te' carbohydrates, twice thar caffeine 'n twice yonder taste. To make it stand out more on ye shelves 'n to give it an extra kick, ye Quantum included a mild radioactive strontium isotope (and an eighteenth fruit flavor - pomegranate). ye effect was a drink that not only boosted yer energy, but also glowed with a bright blue light. Whilst no ill effects were recorded by ye Grub 'n Drug Administration, ye isotope also caused ye drinker's urine to glow.'