News: RIO UPDATE 1-Rio Tinto to probe incident of missing radioactive capsule

(Adds details on background, search operation)

Feb 1 (Reuters) - Rio Tinto Ltd (RIO) said on Wednesday it will investigate how a radioactive capsule used to measure iron ore feed at its mine in the Pilbara region was lost in the vast Outback after authorities located it following a week-long search.

Authorities in Western Australia undertook an extensive search operation for a small silver radioactive capsule after a contractor hired by the miner lost the coin-sized gauge when in transit, sparking a radiation alert across parts of the state.

Filled with Caesium-137, the gauge emits radiation equal to 10 X-rays an hour.

The Anglo-Australian miner said it will investigate the incident thoroughly to ensure a situation of this sort does not repeat.

"As part of our investigation, we will be assessing whether our processes and protocols, including the use of specialist contractors to package and transport radioactive materials, are appropriate," Rio's Iron Ore Chief Executive Simon Trott said.

The search to find the capsule used to measure the density of iron ore feed from Rio's Gudai-Darri mine in the state's remote Kimberley region involved at least six government agencies including the Department of Defence, the police and the Australian Nuclear and Science Technology Organisation.