The device, part of a sensor used in mining, is believed to have fallen off the back of a truck while in transit.
The authorities in Western Australia are searching for a dangerously radioactive capsule, which they believe fell off a truck while being transported.
But they have a problem: The capsule is smaller than a penny, while the search zone is a stretch of vast desert highway about as long as California’s coastline.
The capsule, a small silver cylinder measuring 0.3 inches by 0.2 inches, came from a Rio Tinto mine and formed a part of a sensor used in mining. The sensor had been put onto a truck and driven from the mine, near Newman in the remote north of Western Australia, to Perth, the state’s capital, on a trip that took several days.
The capsule, which contains a small amount of cesium-137, is dangerously radioactive, according to the authorities. An hour of exposure at about a meter away is the equivalent of having 10 X-rays, and prolonged contact can cause skin burns, acute radiation sickness and cancer, they said.
The truck carrying the sensor arrived in Perth on Jan. 16. On Friday, nearly two weeks later, the authorities called an emergency news conference to alert the public that the capsule had disappeared somewhere along the 1,400-kilometer, or 870-mile, journey.
“We want the public to be alert to the possibility of finding the small capsule and the risks,” David Gill, a chief superintendent for the Western Australia emergency services department, said at a news conference on Friday.
The state’s chief health officer, Dr. Andrew Robertson, warned the public to stay at least five meters away from the capsule if they spot it.
The authorities have acknowledged that they have a vast distance to cover, and that the search is likely to take “weeks not days.” But they hope it will be a little easier than looking for a needle in a haystack.
“What we are not doing is trying to find a tiny little device by eyesight,” Darryl Ray, the acting superintendent for Western Australia’s Department of Fire and Emergency Services, said at a news conference on Saturday. “We are using the radiation detectors to locate the gamma rays, using the meters, that will help us then locate the small device.”
The news of a misplaced radioactive cylinder had many on the internet making the joke: Is Homer Simpson to blame?
The capsule was not lost through cartoonish buffoonery, but through an almost cinematic series of events.
According to the authorities, the sensor containing the capsule was placed inside a wooden box, which was screwed onto a pallet and placed in the back of a flatbed truck.
They believe that vibrations from the truck caused the sensor to shake apart and also dislodged a mounting bolt, leaving a hole in the bottom of the box. The capsule is believed to have fallen out of the sensor, through the bolt-hole, onto the surface of the truck, and bounced off into the road.
Although the truck made the journey from Jan. 12 to Jan. 16, the capsule was not discovered to be missing until Jan. 25. The box that the sensor was stored in was “completely secure on arrival,” when it arrived in Perth, where it was put into protective storage, Dr. Robertson, the public health official, said on Friday. It was only when the box was unpacked for inspection for the first time on Jan. 25 that the capsule was discovered missing, he added.
When the box was opened, it was discovered that the sensor had “broken apart,” Dr. Robertson told a local radio station. “It was literally in pieces.”
Dr. Robertson added that the authorities were alerted late on Jan. 25 and that they spent the next day scouring all of the probable places the capsule could be, like the pickup and drop-off sites, before making the decision to notify the public.
The police believe the disappearance was an accident, and there is no evidence that the box was tampered with after arriving in Perth, he said. But he added that it was unusual for a sensor, or gauge, to fall apart and that the authorities would investigate how the situation had been handled.
“These gauges are designed to be robust and to be used in industrial settings where they may be exposed to weather and vibration,” Dr. Robertson said at a news conference on Saturday, “so it is unusual for a gauge to come apart like this one has.”
Rio Tinto, one of the country’s largest mining corporations, said in a statement that it learned the capsule was missing on Jan. 25 from the contractor it had hired to handle and package the capsule before it was transported.