Regulators act after Wal-Mart loses radioactive signs

LITTLE ROCK -- At issue are glow-in-the-dark signs that contain tritium, a hydrogen isotope with a radioactive strength similar to that of material in many smoke alarms.

The Nuclear Regulatory Commission has not told any organization to stop using the signs, which it says are "inherently safe." And no special license or worker training is required to handle them.

But disregarding federal rules for disposing of the signs can lead to an expensive cleanup later because "a damaged or broken sign could cause minor radioactive contamination of the immediate vicinity," according to a fact sheet on the NRC website.

The NRC says tritium emits "low-energy beta radiation that cannot penetrate a sheet of paper or clothing. If inhaled, it leaves the body relatively quickly."

Wal-Mart spokeswoman Daphne Moore said the signs were used in about 4,500 Walmart facilities in the U.S. and Puerto Rico. Wal-Mart bought the missing ones between 2000 and 2007, when it built or remodeled thousands of Walmart, Sam's Club and Neighborhood Market stores in the U.S.

The NRC said Wal-Mart bought 70,000 of the signs in all.

The agency asked 61 entities from the Church of Jesus Christ of Latter Day Saints in Salt Lake City to the Outrigger Hotel in Honolulu — any buyer of more than 500 signs — to inventory them and report whether any could not be accounted for, according to the release.

"Wal-Mart's inability to account for all the tritium exit signs the company purchased demonstrates that organizations may not be fully aware of the regulatory requirements for owning these signs," said George Pangburn, NRC deputy director for Federal and State Materials and Environmental Management Programs.

The world's largest retailer said Tuesday it has checked all of its U.S. stores and removed any signs it found.