How did a radioactive capsule go missing in Australia and how dangerous is it?
Australian authorities are mounting an extensive search for a tiny radioactive capsule believed to have fallen out of a road train - a truck with multiple trailers - that travelled 1,400 km in Western Australia. Here's what you need to know:
WHAT IS IT?
The silver capsule is just 6 mm in diameter and 8 mm long and was part of a gauge used to measure the density of iron ore feed at Rio Tinto's RIO.AX remote Gudai-Darri mine.
HOW DID IT GO MISSING?
The gauge, packaged by a specialist contractor, was picked up from the mine on Jan. 12, by a separate logistics company. When it was unpacked on Jan. 25, it was found broken apart, with one of its four mounting bolts as well as screws and the capsule missing.
Authorities suspect vibrations from the road train caused the gauge to break apart and the capsule fell out.
HOW DANGEROUS IS THE CAPSULE?
Filled with Caesium-137, it emits radiation equal to 10 X-rays an hour. Authorities have issued a radiation alert for large parts of Western Australia and if it is spotted, recommend that people stay at least five metres (16.5 feet) away as exposure could cause radiation burns or sickness.
But just driving past it is believed to be of relatively low risk.
WHAT DOES THE SEARCH INVOLVE?
The road train travelled from the mine in the state's remote Kimberley region and arrived at a storage facility in the suburbs of Perth on Jan. 16.
Search crews are traveling north and south along the state's Great Northern Highway as well as other sections of the road train's journey with specialized radiation detection equipment. The Department of Fire and Emergency Services said on Monday it will take five days to cover the road train's route. It said on Tuesday that more than 660 km had been searched so far.
The search involves at least five other government agencies including the Department of Defence, the police, the Australian Nuclear and Science Technology Organisation and the Australian Radiation Protection and Nuclear Safety Agency.
(Reporting by Melanie Burton and Lewis Jackson; Editing by Edwina Gibbs)
CTVNews.ca Top Stories
Biden and Trudeau announce updates on clean energy, migration and defence
U.S President Joe Biden and Prime Minister Justin Trudeau have announced updates on a number of cross-border issues, after a day of meetings on Parliament Hill.

LIVE UPDATES | Watch live coverage of U.S. President Joe Biden's trip to Canada
As Joe Biden makes his first trip to Canada as president of the United States, CTVNews.ca is offering live coverage of the leader's visit. Follow our live blog on CTVNews.ca and the CTV News app for the latest updates.
Incredible photos show northern lights dancing across much of Canada
Sky-gazers and shutterbugs across much of Canada were treated to a spectacular display of northern lights Thursday night and into Friday morning.
Ontario crypto king kidnapped, tortured in an attempt to get millions in ransom, documents say
Ontario’s self-described crypto king was allegedly abducted, tortured, and beaten for days as his kidnappers looked to solicit millions in ransom, his father told a court in December.
Eugene Levy, Sarah Polley, Jean Chretien, the two Michaels among guests at Biden gala dinner
Notable people will be in attendance at Friday’s gala dinner with U.S. President Joe Biden, hosted by Prime Minister Justin Trudeau and his wife at the Canadian Aviation and Space Museum, including former prime ministers and celebrities.
Sophie Gregoire Trudeau introduces Jill Biden to curling during Ottawa visit
The first lady of the United States got a sweeping introduction to Canadian sports culture in Ottawa Friday as Sophie Gregoire Trudeau took Jill Biden to the curling rink for her first trip to Ottawa.
U.S.-Canada migration deal aims to end walk-around crossings
The immigration deal announced Friday by U.S. President Joe Biden and Prime Minister Justin Trudeau aims to shut down a process that has enabled tens of thousands of immigrants from across the world to move between the two countries along a back road between New York state and Quebec.
W5 Investigates | 'Canadians should be very concerned about their drinking water': W5 investigates asbestos cement pipes
W5 investigates aging asbestos pipes across Canada and the potential health hazards if it ends up in your tap water. Watch W5's 'Something in the Water' Saturday at 7 p.m. on CTV.
Gwyneth Paltrow expected to testify in ski collision trial
Gwyneth Paltrow is expected to testify Friday in a trial over a 2016 ski collision at a Utah ski resort, where a man claims that the movie star's recklessness caused broken ribs, brain damage and lasting physical injuries.