The WR-1 organic-cooled research reactor was built starting in 1963, at the new Atomic Energy of Canada Limited (AECL) Whiteshell Nuclear Research Establishment (WNRE, but now named Whiteshell Laboratories).   The WNRE site was built along the Winnipeg River, 100 km east-northeast of Winnipeg (The Winnipeg River does not flow past Winnipeg, but meanders from the Lake of the Woods to Lake Winnipeg).

The 60 MW (thermal) WR-1 research reactor was designed and built by Canadian General Electric for $14.5 million.   The reactor was unique, in that it had vertical fuel channels, and the fuel was cooled by an organic liquid (an oil) rather than water.   The neutrons were moderated by cool heavy water in a large calandria vessel surrounding the fuel channels.   The reactor first achieved criticality on November 1 1965, and was used as a test reactor for the proposed organic-cooled CANDU power reactor.   When that program ceased in 1972,   WR­1 was used for irradiation, experimentation and heating the WNRE site.

The reactor was a busy place, usually working around the clock.   It had an availability (the amount of time it was available to operate) of 85% over its lifetime, which was (and is) exceptionally high for a research reactor.   Using an organic coolant meant the reactor was run at low operating pressures, and had very low corrosion rates.   The organic coolant also meant the reactor could be run at high temperatures, with outlet temperatures up to 425^oC (!)

WR­1 was shut down for the last time on May 17 1985, ostensibly for economic reasons, although it was the youngest of AECL's large research reactors.   The reactor is no more, or at least not much remains.   It has been defuelled and largely disassembled. The reactor is in an interim decommissioning stage - monitored safe storage - awaiting the passage of a few more years for the radiation fields (from the activated piping in the core) to decrease further before the removal of fuel channels and the calandria vessel.   The final result will be either a "green-field" site or a building for non-radioactive industrial use.

The various auxiliary rooms were converted to offices such as my own, which is about 25 m from the reactor core.   The control room is half its former size, and now only contains monitoring instruments.   An operator is on site during the day, and on call at night and weekends - a continuous operator presence is no longer required since the reactor is defuelled and in long-term monitored storage.   The reactor hall is closed with the lights off, so one cannot normally view the huge vertical fuelling machine nor stand on the deck plate directly over the core.

One of the large concrete heat exchanger rooms found a new lease on life as the Large-Scale Gas Mixing Facility.   All the old reactor piping was removed from room, the flooring and ventilation were rearranged, and the walls were cleaned and repainted.   Instrumentation, gas feed lines, a steam supply and a control room were added.   The result is a unique laboratory for studying gas mixing in a large volume with a controlled environment.   This is important research, to understand how steam and light gases would mix and condense inside a reactor containment building under postulated reactor accident conditions.   The facility, with its thick concrete walls, simulates a reactor containment building, with respect to gas mixing and steam condensation.   The facility is within the larger reactor building, so the environment outside the facility is controlled; a controlled environment is always an asset in research!

To the outside world the most noticeable change in the WR-1 reactor is the ventilation stack.   The stack was known as the "stank" - a combination emergency coolant tank and ventilation stack - but the tank part (the ball at the top) was removed a few years ago, after WR-1 had been defuelled and disassembled.   It was checked for any contamination, then released for scrap.   I believe it became a storage bin on someone's farm. The stank is shown on page 1 of the technical description of WR-1.

The legacy of the successful WR-1 reactor is that organic coolants are still being considered for future reactor designs - they can operate hotter and at lower pressures than water-cooled reactors.   Higher operating temperatures would increase the thermal efficiency of power reactors (the amount of electricity produced divided by the amount of heat produced in the reactor core).   Lower pressures would reduce maintenance costs and pressure vessel design requirements.   Also, the moderator-dump concept used in WR-1 lives on in Canada's next research reactor - the Irradiation Research Facility (IRF).

A public brochure, updated in March 1982, is found at the following four sites:

A) WR-1 Whiteshell Reactor No. 1

B) WR-1: Unique Among Research Reactors

C) WR-1 Design Details

D) Fact Sheet: WR-1 Reactor

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