Sorry about that, my day or two turned into a week or two
I've reviewed the savegame and here is what I see;
Daily Petroleum Demand is 9M Barrels. Of this demand, ~ 3.7M is used by the population. Another 3.8M is used for making industrial goods. 1.6M barrels are being used for the production of electricity. I got these numbers from the Production department <F7>, select Petroleum, from the second panel select Consumption/Usage
For Electricity, 32% of your power needs are provided by cities which are consuming your 1.6B barrels of oil. I got this from the popup industry screen by double clicking a power plant
You're daily Petroleum production is only 7 million so you'll be forced to import. By turning on your deactivated nuclear plant and setting industrial goods to demand instead of capacity decreased Petroleum demand to 8.1M. It also reduced your reliance on Petroleum for power (1.1M instead of 1.6B and 28% instead of 32%). Since you have 3.6 years stock of military goods you could turn off military goods production to further reduce your raw material needs while you build more nuclear power plants (of course, that will make you reliant on Uranium imports).
Either way, the math all looks fine.