DENVER -- The Transportation Security Administration said a security screener at Denver International Airport has been reprimanded for taking a ride through an X-ray machine used to check carry-on luggage.

While the TSA won't say why it happened, other workers said the employee wanted to go through X-ray so that he could see what was inside his brain.

TSA spokesman Mike Fierberg said it happened about three months ago while the screener was working at a passenger checkpoint. He won't release the screener's name or the punishment.

Fierberg says no passengers or aircraft were endangered but the behavior was unprofessional.

As for why it happened, Fierberg said, "I cannot ascribe any sort of motive to why anyone would do this."

He won't comment about the machine's effect on a human body but the machine's manufacturer told reporters that the radiation is minimal, about 50 times less than the exposure received during a chest X-ray.

Fierberg said it doesn't even damage low-speed film.

Critics question TSA's management skills and supervision for allowing such a thing to happen.

"We expect more from our screeners and, by and large, they are a highly trained work force," Fierberg said.