The Nuclear Power Demonstration (NPD) reactor at Rolphton, ON, was Canada’s first venture into electricity production from nuclear fission. Discussions on the possible construction of a power-producing reactor began in late 1952 and by mid-1953 had reached a point where Ontario Hydro were considering a proposal to build a 5 MWe station “in the vicinity of Chalk River”. In 1954 a Nuclear Power Branch was established at Chalk River. It was headed by H.A. Smith of the Hydro-Electric Power Commission of Ontario (HEPCO) and staffed by a combination of engineers from AECL and five other Canadian utilities. Later that year an agreement was reached to form a partnership between AECL, HEPCO and Canadian General Electric (CGE) for the construction of the facility.
The first decision to be made was the location of the reactor. This turned out to be the simplest of the many important questions to be solved. A site near Rolphton, ON, just downstream of HEPCO’s recently-built Des Joachims hydro-electric dam, was chosen and the ground-breaking ceremony was held in September 1956.
The next major decisions were much more difficult to resolve. They involved not only the type of reactor, the type of fuel, the materials to be used, final output power and economic problems as costs seemed to be spiraling as the design developed. By mid-1956 a design emerged that would see a reactor the would be enclosed in a large, thick-walled (13 cm) steel-alloy vessel with vertical fuel rods. This reactor was known as Nuclear Power Demonstration (NPD) and construction began with a ceremonial sod-turning on September 19, 1956.
This was not, however, to be the final design. Changes, determined in part by information learned during the irradiation of US nuclear-submarine fuel in the NRX reactor at Chalk River, were afoot that led to the initial design being literally “turned-on-its-side”. A new design, championed by W.B. Lewis, emerged: a horizontal calandria with pressure tubes for the fuel, which would be assembled in bundles and incorporating on-line refueling. This was– basically the CANDU design, and the design power was increased to 20 MWe.
No more major design changes were introduced after the decision to proceed with the horizontal pressure-tube design and construction proceeded with a majority of the large components being built by CGE in Peterborough, ON, and arriving in Rolphton in a large highway convoy in 1961. Construction was finally completed, first criticality (operation)was on April 11, 1962, and first nuclear-generated electricity was fed to the Ontario grid on June 4, 1962.
By 1987 NPD had been in operation for 25 years, despite a 1962-predicted lifetime of only 10 years. In addition to providing electrical power to the Ontario grid system, it had provided answers to of a wide range of questions regarding materials that would be incorporated into the larger CANDU reactors. In addition, it had provided an excellent training ground for the many nuclear operators needed to operate Ontario’s expanding nuclear fleet. At this point the question arose as to how long this small unit should continue to operate.
