Radiation levels at Japan's Fukushima nuclear plant have reached such alarming levels that a robot sent to inspect and clean a damaged reactor had to be pulled back fearing damage to its system.

Reports emerged last week about how the radiation levels inside the containment vessel of reactor No. 2 at Fukushima reached an astonishing 530 sieverts per hour, a level high enough to kill a human within seconds. Now a Tokyo Electric Power Co (TEPCO) deployed robot suffered damages owing to these excessively high levels of radiation.

It was the first time that a robot had entered the reactor since the earthquake and tsunami disaster six years ago. It was sent inside to inspect and clean a passage of the damaged reactor, but just two hours into its deployment the camera began to fail.

The robot only covered a part of the course it was supposed to take while removing debris with a scraper. Had it entered deeper into the reactor it may have been completely destroyed. Its operators aborted the mission before losing complete control of the probe.

TEPCO was scheduled to send it a second robot, Scorpion, for the same task. But now they are examining the failed robot and will only then decide whether to deploy the robot further or not.

"We will further study Thursday's outcome before deciding on the deployment of the scorpion," said TEPCO spokesman Takahiro Kimoto.

The latest incident reflects a larger hoard of challenges in decommissioning the wrecked nuclear plant including the limitation of subsequent probes that may require more radiation-resistant cameras and other equipment according to Kimoto.

fukushima nuclar power station 2016
Fukushima nuclear power plant the day before the five-year anniversary of the earthquake and tsunami disaster. REUTERS/Kyodo

It is however, important to note that the radiation is well contained within the plant, and is not affecting regions nearby. There have been reports of no new leaks from the facility or radiation leaking into the air or sea. Since TEPCO's attempt is the first to get so close to the melted fuel it is likely to reflect even higher radiation readings.