The company in charge of the ruined Fukushima No. 1 nuclear plant revealed Thursday it needed new ideas to design robots capable of surviving the high levels of radiation inside the site's reactors, which were damaged in a 2011 earthquake and its resulting tsunami.

The Tokyo Electric Power Company (Tepco) has hit a new obstacle since being tasked with cleaning up the worst nuclear incident since the 1986 Chernobyl disaster in the Soviet Union. The exploratory robot, specially designed to navigate the underwater sections of the reactor, died last month after being exposed to "unimaginable" levels of radiation nearly nine times more potent than the previous highest dose recorded. Naohiro Masuda, president of Tepco's Fukushima Daiichi Decommissioning project, told reporters that the company had to rethink its methods in order to examine and extract the hazardous material stuck in the plant's second reactor.

“We should think out of the box so we can examine the bottom of the core and how melted fuel debris spread out,” Masuda said, according to the Japan Times.

Tepco's Fukushima No. 1 nuclear plant began operations in 1971 and was severely damaged by a deadly March 2011 earthquake and tsunami that killed over 15,000 people in Japan. The massive release of radiation forced the government to evacuate about 160,000 people and establish a 310-square mile exclusion zone deemed uninhabitable. Tepco has since embarked on an estimated $188 billion cleanup process that has included the treatment of contaminated water dumped on the site to prevent three out of six reactors from melting down completely.

Tepco reportedly was scheduled to send another waterproof robot into the site's first reactor in the coming weeks as researchers searched for a solution to enter the third reactor. Despite the setbacks in reactor two, the company said it wished to remain on schedule, beginning work in 2021.