Alert over tiny missing radioactive cylinder
www.canada.com Renata D'Aliesio The Edmonton Journal Saturday, January 25, 2003
EDMONTON - A dangerous radioactive cylinder smaller than a triple-A battery has gone missing, igniting a search stretching 600 kilometres from Alberta to Saskatchewan.
The silver metallic cylinder contains cesium 137, which emits gamma radiation and poses a serious health risk if it's near or held by someone for mere minutes. It was last seen Sunday at an oil-drilling site 35 kilometres southwest of the village of Pierceland in northwestern Saskatchewan.
Since then, the Tucker Wireline Services Canada truck carrying the cylinder has been to the company's branch in Leduc and to another oil-drilling site in Wandering River, about 50 kilometres north of Athabasca. It was in Wandering River on Tuesday that the cylinder was found to be missing.
The company has been looking for it ever since, but a search of Wandering River, Leduc, Pierceland and routes in between has turned up nothing, says Jeff Levack, sales manager at the company's Canadian head office in Calgary.
"It's a major concern," Levack said Friday. "The search is focusing along the highways, and in the bush where we were in Saskatchewan.
"Where we would really have a problem is if someone were to find the source, not know what it is, and pick it up and carry it around in their pocket."
The cylinder is used along with a five-metre-long tool to determine the density of rock within a hole drilled for oil. It should be kept in a secure case separate from the tool when it's not being used, said Carl Schumaker, a radiation safety expert at the University of Alberta.
"I think that the likelihood that somebody is going to receive a very high dose of radiation from the source is probably minimal simply because it's probably laying somewhere adrift," Schumaker said.
"The longer the time goes that it's not found, the more likely it is that somebody eventually is going to be exposed to it."
If someone were to pick up the cylinder, he or she wouldn't immediately know it was dangerous, Schumaker says. There are no warning marks, nor does the cylinder feel harmful when touched.
"Unlike a hot object, where you are going to feel the burn right away and you're going to drop it, a radiation burn would not happen immediately," Schumaker said. "It would take several hours, maybe several days or longer, before the skin would start to show the damage."
Aside from radiation burns, exposure to cesium 137 may also increase the risk of cancer. This can happen even without touching the cylinder, Schumaker said.
In terms of radiation measurement, the cylinder is rated at two Curies. By comparison, United States estimates of the radiation from the nuclear power-plant explosion at Chornobyl in 1986 have been in the range of three billion Curies.
Cesium 137 was found at Chornobyl after the accident.
Standing just a metre away from the cylinder for 10 minutes would expose a person to more radiation than is deemed safe for an entire year, Schumaker said.
This isn't the first time cylinders containing cesium 137 have gone astray in Canada. Since 1996, there have been three other incidents in which radioactive cylinders have been lost at oil sites, all in Alberta, said Michel Cleroux, spokesman for the Canadian Nuclear Safety Commission. In those cases, the cylinders were located at the sites where they were used before anyone was exposed to dangerous levels of cesium 137.
Tucker Wireline has brought in an outside expert to help its workers with the search. Levack said the company has hired the same man who worked with Canadian military officials in New Brunswick to locate six radioactive gauges. The gauges, which were mistakenly thrown out in 1998, were eventually found in scrap yards in New Brunswick and Quebec.
There have been no serious medical or environmental disasters connected to cesium 137 in Canada. The cylinder is not considered a risk to the environment.
But it has been linked to a nuclear disaster in Goiania, Brazil, where scavengers in 1987 dismantled an abandoned metal canister containing 1,400 Curies of cesium 137. It was days before anyone realized the canister's danger. Four people died from radiation exposure, while scores of others fell sick.
Tucker Wireline is hopeful its cylinder will be found. Levack says workers are using gamma-radiation detectors mounted on trucks to search for it.
"It's like looking for your car keys. You have two or three very obvious places and when they don't show up there you have to really start thinking," he said. "It seems like a large area that we're looking over, but it's really a thin band because the source is either on the locations where we were working or on the road somewhere in between."
The Canadian Nuclear Safety Commission has ordered the company to suspend work with radioactive materials.
Cleroux said anyone who finds the missing cylinder should call Tucker at 1-888-444-5647, or the RCMP.
There is a possibility the cylinder will never be found. If that's the case, it would pose a health risk for decades to come, Schumaker said. The half-life of cesium 137 is 30 years, which means it will take that long for it to lose half its strength.
Don McGladdery, a councillor with the county of Athabasca, said he doesn't believe residents should be greatly concerned about the missing cylinder.
"I'm sure they'll find it," the former engineer said. "These companies have the highest standards and it's unusual for them to lose something like this."
McGladdery said about 100 people live in the Wandering River area. The population of Pierceland is about 460.