The military says a preliminary study has concluded the public is not at risk from depleted uranium at the Pohakuloa Training Area on the Big Island.

The Army conducted the study as part of its licensing application to the Nuclear Regulatory Commission for a site-specific environmental radiation monitoring plan.

According to the report, only three pieces of the radioactive material have been found at Pohakuloa and it is thought the remainder, if any, likely fell into cracks in the lava.

The presence of depleted uranium at the training area was confirmed by the Army in 2007.

After years of denials of using the material in the islands, the Army said soldiers training in Hawai'i fired 714 spotting rounds containing depleted uranium in the 1960s.