What’s the waste product? This is a nuclear reaction we’re talking about here. Since it’s fusion, basically reproducing the sun.
Helios is the Greek Sun god, whom the Romans called Sol. Most often, people viewed or portrayed Helios as a mighty charioteer, driving his flaming chariot (or gleaming horses) from east to west across the sky each day. - http://www.greekmyths-greekmythology.com/helios-sun-god/. . . and the physical product of the fusion of heavy hydrogen is - heliumI wouldn’t trouble myself too much about the environmental impact of a few tons of helium - it’s inert and, if released, promptly sequesters itself by ascending to the top of the atmosphere, well out of the way of any living creature.