Tokyo Electric Power Co., known also as Tepco, said radioactive alarms were triggered at a monitoring station outside the main operations base.
"The contamination measurement conducted through the exit monitor at the entrance control facility found out that two people, out of those who had been waiting for a bus in front of the main anti-earthquake building, had their bodies contaminated," the company said in a statement.
Tepco said the level of contamination was low, the workers were cleaned and later released.
"We are currently conducting a detailed investigation of the cause of their body contamination," the company said.
Four Japanese utility companies last month applied to nuclear regulators to determine if their 10 reactors meet safety requirements. New rules require operators to enact tough counter-terrorism measures, emergency procedures and leak-protection systems.
A magnitude-9 earthquake and tsunami crippled the Fukushima Daiichi nuclear power station in 2011. Tepco in July said it uncovered "high densities" of radioactive material in groundwater observation sites at the facility.