WR-1
Encyclopedia
The WR-1 reactor was a research reactor
located at AECL
's Whiteshell Laboratories
, located near Pinawa, Manitoba
.
The 60 MWt WR-1 was designed and built by Canadian General Electric
, and first achieved criticality
in 1965. The reactor was built at a cost of $14.5 Million CDN . The original purpose of the unit was as a test reactor for a proposed organic-cooled CANDU power reactor. When that program ceased in 1972, WR-1 was used for irradiation
, experimentation and heating the WNRE site. WR-1 was shut down for the last time in 1985, was defuelled, and is now undergoing decommissioning.
by cool heavy water
in a large calandria vessel surrounding the fuel channels. The reactor did not use conventional control rods, but relied on control of the level of the heavy water moderator to adjust the power output. The reactor could be shut down quickly (SCRAM
) by rapid dumping of the moderator. The organic liquid, called OS-84, that was selected as a coolant in WR-1 is a mixture of terphenyl
s treated catalytically with hydrogen
to produce 40 percent saturated hydrocarbons. The terphenyls are petrochemical
derivatives that were readily available and were already in use as heat transfer media. Using an organic coolant meant the reactor was run at low operating pressures, and had very low corrosion
rates. The low corrosion rates allowed it to use metallic uranium and uranium carbide fuels, which corrode in water. The metallic fuel conducts heat better, so that a higher power core could be used in the same space.
The organic coolant also meant the reactor could be run at high temperatures, with outlet temperatures up to 425°C.
's large research reactors. The reactor is currently in an interim decommissioning stage, defuelled and largely disassembled. The site will be returned to Green Field status at the end of decommissioning.
Research reactor
Research reactors are nuclear reactors that serve primarily as a neutron source. They are also called non-power reactors, in contrast to power reactors that are used for electricity production, heat generation, or maritime propulsion.-Purpose:...
located at AECL
AECL
AECL is an acronym that can stand for:*Advanced Electronics Company Limited*Atomic Energy of Canada Limited*Australian Egg Corporation Limited...
's Whiteshell Laboratories
Whiteshell Laboratories
The Whiteshell Nuclear Research Establishment, now Whiteshell Laboratories, was established by the Government of Canada in 1963 as an AECL research laboratory in Pinawa, Manitoba...
, located near Pinawa, Manitoba
Manitoba
Manitoba is a Canadian prairie province with an area of . The province has over 110,000 lakes and has a largely continental climate because of its flat topography. Agriculture, mostly concentrated in the fertile southern and western parts of the province, is vital to the province's economy; other...
.
The 60 MWt WR-1 was designed and built by Canadian General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...
, and first achieved criticality
Critical mass
A critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties A critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The...
in 1965. The reactor was built at a cost of $14.5 Million CDN . The original purpose of the unit was as a test reactor for a proposed organic-cooled CANDU power reactor. When that program ceased in 1972, WR-1 was used for irradiation
Irradiation
Irradiation is the process by which an object is exposed to radiation. The exposure can originate from various sources, including natural sources. Most frequently the term refers to ionizing radiation, and to a level of radiation that will serve a specific purpose, rather than radiation exposure to...
, experimentation and heating the WNRE site. WR-1 was shut down for the last time in 1985, was defuelled, and is now undergoing decommissioning.
Design
The reactor had vertical fuel channels, was cooled by an organic liquid (an oil) rather than water. The neutrons were moderatedNeutron moderator
In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235....
by cool heavy water
Heavy water
Heavy water is water highly enriched in the hydrogen isotope deuterium; e.g., heavy water used in CANDU reactors is 99.75% enriched by hydrogen atom-fraction...
in a large calandria vessel surrounding the fuel channels. The reactor did not use conventional control rods, but relied on control of the level of the heavy water moderator to adjust the power output. The reactor could be shut down quickly (SCRAM
Scram
A scram or SCRAM is an emergency shutdown of a nuclear reactor – though the term has been extended to cover shutdowns of other complex operations, such as server farms and even large model railroads...
) by rapid dumping of the moderator. The organic liquid, called OS-84, that was selected as a coolant in WR-1 is a mixture of terphenyl
Terphenyl
Terphenyls are a group of closely related aromatic hydrocarbons. Also known as diphenylbenzenes or triphenyls, they consist of a central benzene ring substituted with two phenyl groups. The three isomers are ortho-terphenyl, meta-terphenyl, and para-terphenyl. Commercial grade terphenyl is...
s treated catalytically with hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
to produce 40 percent saturated hydrocarbons. The terphenyls are petrochemical
Petrochemical
Petrochemicals are chemical products derived from petroleum. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable sources such as corn or sugar cane....
derivatives that were readily available and were already in use as heat transfer media. Using an organic coolant meant the reactor was run at low operating pressures, and had very low corrosion
Corrosion
Corrosion is the disintegration of an engineered material into its constituent atoms due to chemical reactions with its surroundings. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen...
rates. The low corrosion rates allowed it to use metallic uranium and uranium carbide fuels, which corrode in water. The metallic fuel conducts heat better, so that a higher power core could be used in the same space.
The organic coolant also meant the reactor could be run at high temperatures, with outlet temperatures up to 425°C.
Status
WR1 was shut down for the last time ostensibly for economic reasons, onMay 17, 1985 although it was the youngest of AECLAtomic Energy of Canada Limited
Atomic Energy of Canada Limited or AECL is a Canadian federal Crown corporation and Canada's largest nuclear science and technology laboratory...
's large research reactors. The reactor is currently in an interim decommissioning stage, defuelled and largely disassembled. The site will be returned to Green Field status at the end of decommissioning.