Whiteshell Laboratories – Manitoba’S Contribution to Nuclear Engineering in Canada
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Whiteshell Laboratories – Manitoba’s Contribution to Nuclear Engineering in Canada Prepared By Chris Saunders, P. Eng. and Ray Sochaski, P.Eng; Life Member Atomic Energy of Canada Limited (AECL) established a role in Manitoba in 1963 when the Whiteshell Nuclear J.L. Gray Research Establishment (WNRE; later renamed Whiteshell James Lorne Gray was born in Brandon, Laboratories) first took shape. WNRE was Canada’s second Manitoba in 1913. After nuclear science research and development laboratory and public school in the first facility of its kind in western Canada. Through its Winnipeg, he graduated years of operation, the people of the WNRE made with a Masters in Mechanical Engineering significant contributions to the science and engineering from the University of knowledge of Canada’s nuclear industry. This article Saskatchewan in 1938. He highlights just a few of these many accomplishments. joined the Royal Canadian Air Force in 1939. In the Beginning Mr. Gray’s scientific career began at the National Research In the late 1950s AECL’s managers thought Chalk River Council in 1948. He was assigned to the “Chalk River” Laboratories (CRL) was nearing the saturation point. A project. He advanced to become President of AECL in 1958. For the next 16 years he led the corporation through quick survey indicated that three provinces were lacking an impressive growth period that saw Canada become a federal research facilities: Newfoundland, Alberta and leader in nuclear engineering and technologies. Manitoba. Newfoundland, it was felt was not an option at Mr. Gray was appointed a Companion of the Order of the time, having joined Canada less than ten years Canada in 1969 and was awarded the Professional previously in 1949. Alberta had no need of atomic energy, Engineers Gold Medal by the Association of Professional blessed as it was with abundant oil and gas. So it would be Engineers of Ontario in 1973. Manitoba. AECL wanted this new research laboratory to develop the organically cooled reactor. A preliminary survey went forward under the supervision of Shawinigan Engineering. AECL president J.L. Gray journeyed to Manitoba to meet with premier Duff Roblin. In November, 1959, he reported progress to the board: a probable site near the Seven Sisters Falls on the Winnipeg River; and an opinion by the federal government's housing agency that a new town would be developed. Negotiations with Manitoba were complicated. The new research centre would not be costless for the province. It would have to look after some of the infrastructure, such as roads and a bridge across the Winnipeg River, as well as housekeeping details. With help from the federal government, an agreement was approved by cabinet on July 21, 1960 and the Whiteshell Nuclear Research Establishment (WNRE) was born. Whiteshell Nuclear Research Establishment in 1965 1 Final agreement was reached on joint facilities, between AECL and Manitoba, just as the company was finalizing their plans for demonstrating organic cooled reactors. It was called simply OTR for Organic Test Reactor. A design would be ready for the start of the construction season in April 1962. Whiteshell Reactor #1 – A Manitoba Milestone The Whiteshell Reactor #1 (WR-1), WNRE’s signature facility, was built starting in 1962. The 60 Megawatt reactor was designed and built by Canadian General Electric for $14.5 million in only three years. By June 1965, WR-1 was substantially complete. WR-1 was built to test the concept of using an organic fluid to cool the reactor. The expected advantage was that they they can operate hotter and at lower pressures than water-cooled reactors. This was because the organic coolant had a lower vapour pressure than water. Higher operating temperatures increase the thermal efficiency of the attached turbine system (the amount of electricity produced divided by the amount of heat produced in the reactor core). Lower pressures reduce maintenance costs and pressure vessel design requirements. It allowed WR-1designers to use thinner-walled pressure tubes, which reduced the number of neutrons absorbed in the tubes, giving the reactor a high Construction in 1964 2 neutron flux. The reactor had vertical fuel channels. Neutrons were moderated by heavy water in a large calandria vessel surrounding the fuel channels. This calandria was a stainless steel tank approximately 5 m high and 2.75 m in diameter. Fifty-four aluminum tubes penetrate the calandria vessel. Pressure tubes, which contained the fuel and circulating organic coolant, were located inside these calandria tubes. The fuel was compacted and sintered uranium dioxide, slightly enriched to provide a useful neutron flux (2.4% U-235 in natural uranium, clad in zirconium-2.5% niobium alloy). The vessel was divided into an upper and lower section. The upper section contained the fuel and, when the reactor was operating, the heavy water moderator. The lower section contained helium gas and collected the moderator spillage from the upper section. The reactor control system maintained the moderator level in the upper section by varying the differential helium Installing the Reactor Vessel pressure between the two reactor sections. When the reactor tripped, the helium gas pressure in the lower section was equalized with the upper section allowing the lower section to rapidly receive the moderator from the upper section and drain to the moderator dump tank. The annuli between the fuel channels and the calandria tubes were purged with CO2 gas to insulate the hot fuel channels from the moderator. Sampling of the CO2 gas provided a means of detecting moderator or organic coolant leaks between the fuel channel and calandria tube. The reactor was surrounded by heavy concrete shielding (> 2 m thick), which formed the reactor vault walls. Heavy concrete (density of 3,500 kg/m3) was also used in the vicinity of the upper and lower access rooms and the shutdown shields. Stepped pipe chases through the concrete provided access for heavy water and helium lines and for the reactor vault exhaust duct. There were also three penetrations for the ion chambers. The inner surfaces of the concrete walls were cooled by embedded cooling coils. The top deck plates provide an operational shield between the upper access space and the reactor hall. The deck plates also supported the fuel transfer flask and provided the necessary radiation shielding during fuelling operations. It consisted of two rotating plates and an outer WR-1’s Fuel Transfer Flask 3 stationary ring. The plates were comprised of cast steel (0.45 m thick) topped by wood fibre hardboard (Masonite; 9 cm thick) and a steel cover plate (0.5 cm thick). The inner (small) rotating plate was supported by the large rotating plate on large ball bearings. The large plate was similarly supported on the stationary outer ring, which, in turn, was supported by the shielding walls of the upper access space. The rotating plates were driven by pinion gears located on the stationary ring and on the large rotating plate, which meshed with gears located at the outer periphery of the large and small rotating plates, respectively. The small rotating plate had two holes for fuelling operations and periscope viewing in the upper access space. The Primary Heat Transport System (PHT) was designed to remove the heat produced in the reactor core. The system was divided into three circuits. The removed heat was dissipated to the Winnipeg River through Whiteshell’s WR-1 Reactor three conventional tube-and-shell heat exchangers. River water was used as the secondary coolant. The PHT system had three similar circuits to achieve flexibility for experimental research. To the outside world the most noticeable feature of the WR-1 reactor was the ventilation stack. The stack was known as the "stank" - a combination emergency coolant tank and ventilation stack. WR-1 Control Room 4 The WR-1 reactor was housed in a building that had 7 floors, 5 of which were below grade. The building was divided into two areas: the lower 4 levels (with restricted access) contained shutdown reactor components, while the upper 3 floors provided office space or laboratory space for experimental programs. The reliability of the WR-1 safety systems was achieved by means of instrument triplication, parameter duplication and frequent testing. Each trip parameter was monitored by three independent sets of instrumentation. Used fuel, irradiated fuel channels and equipment could be safely transferred from the reactor to water-filled storage facilities. After the fuel or equipment had been cleaned or decayed sufficiently, it would be transferred to long-term site storage. WR-1 Operations – Dick Meeker and Phil Roy Experimental Loops A unique feature of WR-1 was its four experimental loops and one out-of-reactor hydraulic test loop. Each in-reactor loop consisted of a fuelled test section in a reactor lattice position and piping equipment and instrumentation in an adjacent loop room to maintain required operating conditions of flow, pressure and temperature in the test section. A fuel position was converted to a loop by disconnecting the inlet and outlet feeders from the PHT and connecting the feeders to the loop inlet and outlet piping. The out-of- reactor hydraulic test facility was capable of handling full-sized fuel channels and fuel assemblies. The loop consisted of a circulation pump, a pressurizing pump, three test sections, three electric heaters, a make-up tank/degassifier, a condenser circuit, a purification circuit, a loop cooler, piping and instrumentation. Frank Orvec and Alex Robertson in WR-1 Control Room 5 November 1, 1965 – Manitoba History WR-1 commissioning proceeded smoothly. As might F.W. Gilbert be expected with a new reactor design, some Fred Gilbert was the forefather modifications were required in the pre-critical phase to of AECL in Manitoba.