Pickering in the six years since Three Mile Island made headlines with a radiation spill, the nuclear power station has become one of the biggest tourist attractions in Pennsylvania, spawning a sideline industry in nuclear joke T-shirts and bumper stickers. In Ontario, Pickering Generating Station, 32 kilometres to the east of Metro Toronto, has had its own much publicized accident. But you won’t find the jokes here. Instead, Ontario Hydro encourages people to visit the plant in the hope that it can convince them that a nuclear reactor is not really a dangerous thing to have in your own back yard – at least if it is a Candu. Walking right into a nuclear reactor and the station’s main control room are the highlights of a fascinating look at the plant’s operations.
Casual visitors are invited to drop in at the Visitors’ Centre, which is open seven days a week and has an array of displays of the hands-on kind at the Ontario Science Centre. Youngsters immediately gravitate toward computer games such as Dream Home and Hangman, which dispense trivial facts as the players push buttons. Learning that a radio consumes 48 cents worth of electricity (or 12 kilowatt hours) a year may not provide the same thrills as a round of Pac-Man, but on a recent mid-week visit there were crowds of school children around every game, eager to try the electronic quizzes.
Cartoons and film shorts present both a humorous history of energy consumption and a physics lesson in the makeup of heavy water, which, one learns, is literally heavier because of an extra neutron in the hydrogen atom.
By simply making a telephone reservation, visitors can arrange to join one of the Saturday morning tours through the station. Age is the only restriction – everyone must be at least 18 to join a group of about a dozen people who get a look at the very heart of the operation. Hard hats, steel-toed shoes and safety glasses, all provided by Hydro, are donned after an introductory film or slide show has prepared them with some rudimentary facts about how the power station works.
As we entered the station, guide Jack Muir, the media and community relations officer, explained that the station was divided into three zones, each signifying a progressively greater likelihood of radioactivity, from none in zone one (largely an office area) to the most in zone three in the immediate vicinity of the reactors. Before passing from one area to another all workers and visitors are required to have their hands and feet monitored by a geiger counter.
Cleanliness seems to be a compulsion here. The first room we see is a laundry. Floors are constantly being wiped. “That is because radioactivity appears in the form of water vapor and dust,” Mr. Muir explained. Workers who must handle radioactive machinery wear balloon-like suits of yellow plastic that are supplied with a flow of fresh air.
Pickering’s Candu reactors are fuelled by cylindrical bundles of natural uranium which are estimated to have roughly one- fifth the radioactivity of the enriched fuel used in many U.S. reactors. Unstable uranium atoms split spontaneously, sending particles flying apart. As they collide with other atoms they create heat. When a moderator, such as the heavy water used in the Candu, is used to slow down the speeding neutrons, it produces a chain reaction. The heat generated by all this activity is collected in heavy water circulating through the fuel tubes. In a boiler heat from the heavy water passes into ordinary water which turns to steam that powers a turbine.
The last of Pickering’s eight nuclear reactors is nearing completion and visitors who come before April will have a chance to walk inside reactor number eight before it goes into operation. Surrounded by 1.2- metre-thick walls of reinforced concrete designed to withstand the impact of a jumbo jet crash, the reactors consume fuel which is inserted, by machine, into tubes. Inside reactor number eight visitors can see the pressurized tubes which, when filled, will hold 4,680 fuel bundles, each weighing 22 kilograms. Fuel loading machines allow the bundles to be removed or added without shutting down the reactor. “Much like putting another log on the fire,” said Mr. Muir.
Used fuel bundles are highly radioactive when they are removed from the reactor and must be stored in a protective bay. At Pickering the bay looks like a giant swimming pool, painted blue and filled with demineralized water. The 30- metre-long pool is estimated to be large enough to hold all the fuel bundles that will be used until 1996.
Questions about spills and the risk of radioactivity get reassuring replies. Mr. Muir explained that reactors one and two remain shut down since an accident in August, 1983, but he was quick to point out that, unlike Three Mile Island, there was no equipment damage, beyond the initial crack in one tube. At Pickering, radioactive fuel and heavy water have been removed and the reactor has been cleansed with a mild acid “similar to what is in a grapefruit.” Three Mile Island has not yet been decontaminated.
The tour’s biggest surprise came not in learning about nuclear reactors, but finding that any visitor who has signed up for the tour can enter the station’s main control room and get a close-up look at its expanse of monitors and controls. Four operators, one for each reactor, are always on duty testing safety systems and recording any work done. Visitors are permitted to take photographs, providing they don’t use a flash. THE TAB The Pickering station makes for an interesting and cheap outing from Toronto. Take Highway 401 east and turn off at the Brock Road exit. Motorists are invited to drop in for a look around the Visitors’ Centre. Adults can book a free tour of the station by calling 839-0465.
A car isn’t necessary to reach the plant. Pickering Transit buses run between the GO train station and the plant. Cross-country skiers may want to bring along their equipment to ski at the plant park. Burns’ night Robbie Burns’ birthday will be celebrated Jan. 26 at Hamilton’s Dundurn Castle with an evening of Scottish country dancing, Highland dancing, a piper, fiddler and an address delivered to the haggis. An informal tour of the castle which includes the kitchens will provide an opportunity to sample some Scottish fare.