The department had offered 48 tours for the public to register for on a first-come, first-serve basis. The registration opened early Monday, but by 6 p.m., all 2,000 spots were filled.
There's still hope for people looking for a spot. Newly available seats will be posted shortly before each tour when cancellations are received.
All registration is on the Internet at www.hanford.gov. The tours start April 2.