in groups of three which can be individually valved out of the heat transport loop, as can the 16 pumps per reactor, with 4 being spare. At Bruce, the number of steam generators and coolant pumps was reduced to 8 and 4 respectively, without any spare pumps, thereby simplifying the piping. The Bruce system permits reactor power level to be adjusted more quickly and easily. Construction costs Bruce A was projected to cost billion (1969), and actually cost $1.8 billion (1978), a 100% over-run. Bruce B was projected to cost $3.9 billion (1976), and actually cost $6 billion (1989) in "dollars of the year," a 50% over-run. These figures are better than for Pickering B or Darlington (at 350%, not accounting for inflation). Cost of generated electricity In 2010, Bruce Power was paid approximately $60 million for contracted, but unused power. On 1 January 2016, Bruce Power began receiving a single contracted price for all output from the site of per megawatt-hour (MWh). This price is partially adjusted annually to account for inflation and wage growth, with additional monthly fuel cost adjustments, and it includes a small payment for Bruce's unique ability to curtail up to 2400 MW of generation (total across all eight units – up to 300 MW per individual unit) via steam bypass operation during periods of surplus generation. During the course of the refurbishment of Units 3–6, the price will be raised in steps to cover individual reactor refurbishment costs, with each increase starting 12 months prior to the start of each individual refurbishment. Each increase will last only until that unit's refurbishment costs, which are fixed prior to refurbishment start, have been recovered. The average price per MWh that will be paid to Bruce Power for all electricity generated from 2016 to 2064 (covering the entire refurbishment period for Units 3–6 plus the entire expected remaining post-refurbishment lifetimes of all eight Bruce Power reactors (including the two that were already refurbished) was estimated to be approximately /MWh in 2017 dollars by the Financial Accountability Office of Ontario. In contrast, the estimated average price of nuclear electricity from all three Ontario nuclear plants during that same 2016–2064 period was estimated to be /MWh in 2017 dollars, the 2017–2018 unit cost of Ontario nuclear power was /MWh, and the current price of electricity for "most residential and small business customers" was /MWh (prior to the Fair Hydro