The detached pipe was connected to a desalination system, Tepco said, which was being used to treat toxic water before storage in tanks.
Tokyo Electric Power Company (Tepco) said the company was measuring the radiation level that the workers were exposed to, the BBC reports.
Meanwhile, a senior official from Japan's Nuclear Regulation Authority (NRA) said the workers had not received a troubling dosage of radiation as they were wearing protective gear.
According to the report, the workers were exposed to beta decay radiation and its particles are very weakly penetrating.
NRA also confirmed that no water splashed in the faces of the clean-up staff, so there was little chance of contamination being ingested by them.
Fukushima was badly damaged by the earthquake and tsunami disaster of March 2011, in which cooling systems for reactors were knocked out, causing meltdowns at three of them.
The plant has been hit by a series of toxic water leaks in recent months, the report added.
--ANI (Posted on 10-10-2013)