period of public hearings and study by an Ontario government all-party committee finished in 1986 with the decision to proceed with the project, which had then risen to $7 billion in actual and committed costs. The final cost was $14.4 billion CAD, almost double the initial construction budget. The project was adversely affected by declining electricity demand forecasts, mounting debt of Ontario Hydro, and the Chernobyl disaster which necessitated safety reviews in mid-construction. Each delay incurred interest charges on debt, which ultimately accounted for 70% of the cost overruns. Inflation during 1977 to 1981 was 46 percent, according to Canada's Consumer Price index. In addition interest rates were running at 20 percent. Improper choice of equipment and a six-month labour stoppage of electrical workers also yielded some of these costs and delays. Discussion of who is to blame for the costs and subsequent debts associated with Darlington often arise during provincial election campaigns, and are often mentioned in anti-nuclear literature. Refurbishment project On October 14, 2016, OPG began Canada’s largest clean infrastructure project – the refurbishment of all four of Darlington’s reactors. According to the Conference Board of Canada, the $12.8 billion investment will generate $14.9 billion in economic benefits to Ontario, including thousands of construction jobs at Darlington and at some 60 Ontario companies supplying components for the work. The project is scheduled for completion by 2026, and will ensure safe plant operation through 2055. The first reactor to be refurbished was Unit 2. In March 2020, it was announced that the refurbishment of Unit 2 was complete, and in April 2020, the reactor achieved criticality for the first time since being reassembled. The reactor was reconnected to the grid in June. New build proposal In 2006, OPG started the federal approvals process to build new nuclear units at the site of its Darlington Nuclear Station. The project proposal involved the construction and operation of up to four nuclear units, with capacity of up to 4,800 MW. A request for proposals (RFP) process for design and construction resulted in bids from Areva NP, Westinghouse, and Atomic Energy of Canada Limited (AECL). In June 2009, the Government of Ontario put the RFP process on hold, citing unexpectedly high bids, and the uncertainty surrounding the future of the only compliant bidder (AECL). In August 2011, the three-member Joint Review Panel (mandated by the Ontario Ministry of the Environment and the Canadian