Expected behavior
Building a Deuterium Power Plant on a planet it is expected that it is using deuterium as fuel. So deuterium should be consumed if the power plant is producing energy.
Actual behavior
A Deuterium Power Plant is only lowering the deuterium production of the deuterium synthesizers. It is not consuming any deuterium if none is produced on the same planet.
How to reproduce
Look at your ressources screen and watch the deuterium production of the Deuterium Synthesizer and the deuterium consumption of the Deuterium Power Plant. The displayed netto production rate - the difference of the two - will be added to your deuterium reservoir. If you lower the production rate of the synthesizer to 0% usually your netto production rate will become negative, but the level of your reservoir will stay at the same , so no deuterium is consumed.
Recording Of The Bug
Production at 100%
Production at 50%
As you see, the net production is lower now.
Production at 0%
As you see, the nett production is negative now.
Production a few seconds alater, still at 0% production rate.
As you see, the inventory of metall and crystal has increased, while the inventory of deuterium has not lowered, despite the fact that net production is negativ.