Scientists Downplay Radiation Threat from Uranium Ore Stored at Grand Canyon

The East Entrance sign welcomes visitors to Grand Canyon National Park. As the park enters its busy season, some seasonal workers say they are being turned away because of a new Park Service rule. (Photo by Michael Quinn/National Park Service)

GRAND CANYON – Grand Canyon National Park’s safety, health and wellness manager caused a stir this week when he reported that three buckets of uranium ore stored in the park’s museum collections building had exposed visitors and staff to radiation for years.

Scientists, however, say unprocessed ore poses little danger unless exposed at very close range for long periods of time.

The buckets of uranium ore, along with samples of many other minerals found at the Grand Canyon, have been stored in the collections building, which visitors can tour by appointment, for two decades. Discovered last summer, the ore was removed from the building and dumped at “the site of its origin,” according to the safety manager’s report.

Uranium at the park was heavily mined during the Cold War. Grand Canyon’s former science director, Martha Hahn, said it’s everywhere. When she lived at the park, she had to move because inspectors found it in her house.

“To say that it was sitting out there and children and employees and everyone is in danger and nobody knew about it seems a little far-fetched to me because there were plenty of safety inspections done in the past,” Hahn said.

The park has spent millions of dollars cleaning up the Orphan Mine, which is 2 miles northwest of Grand Canyon Village on the South Rim. The topsoil has been removed, and the milling site has been fenced off.

The Orphan Mine, which opened on the South Rim in 1906, is 2 miles from Grand Canyon Village. It may be where workers last summer dumped three buckets of uranium ore that had been discovered in the park’s museum collections building. (Photo courtesy National Park Service)

As for the buckets of ore, Grand Canyon senior advisor Jan Balsom said the park is coordinating an independent inspection with the Occupational Safety and Health Administration, the Arizona Department of Health Services and other agencies.

“I don’t want to sound cavalier about it at all because we’re really concerned about risks of uranium in the environment and in our water supplies across the board, which is why we’re hoping for a permanent withdrawal from mining in the area,” Balsam said. “The couple buckets of samples of unprocessed rock aren’t the same sort of threat in my mind. They’re different. And we’re addressing it again. This’ll be the third or fourth team that’s come in in the last six months.”

One thing they plan to find out in the inspection is where the buckets of ore were dumped last summer. “Site of its origin” could mean the Orphan Mine, which opened in 1906.