The U.S. Department of Energy is planning one whale of a birthday bash for the Idaho National Engineering Laboratory's 40th birthday, including a sit-down dinner for up to 20,000 at Idaho State University's Holt Arena.

The INEL, formerly the National Reactor Testing Station, marks its birthday as May 18, 1949, when the Atomic Energy Commission opened its first office in Idaho Falls. Four decades later, the INEL is one of the largest employers in state, with about 10,000 employees.DOE has announced a month-long slate of activities in May to celebrate INEL's anniversary, including a catered dinner at Holt Arena for all INEL employees, including retirees and part-time workers and their guests.

The banquet, scheduled for May 25, will feature a program looking at site history. It will include taped interviews with former Atomic Energy Commission, Energy Research and Development Administration and DOE officials.

Site contractors are springing for the bash and will provide tickets to their employees.

"We wanted to try to get all of our employees at the site involved in one activity where they could all get together," said Nick Nichols, a spokesman for the Department of Energy. "(Holt Arena) was the biggest place we could find."

While DOE officials don't expect all 10,000 employees and their guests to attend, Nichols expects "several thousand people" to come to the catered affair.