“rejecting 2000 megawatt hours of waste heat per hour of operation.””
No the proper units are MWh per hour
A 1 gigawatt nuclear reactor electric is rejecting 2/3s of its 3 gigawatt thermal output. Every second it is producing 3000 megawatts of heat 2/3 of that end up as 40C condenser water.
2000 megawatts per second over an hour period is 2000megawatt hours of heat. So yes what I said is accurate 2000MWh per hour or 48,000 megawatt hours worth of heat per day. MWh is a unit of energy not power.
2000MWh is also 7200 gigajoules which is what the amount of waste heat that would be produced in a single hour of operation of a typical 1GWe reactor.
48GWh per day is another way to say it.