The now destroyed No. 4 reactor building at TEPCO's Fukushima Daiichi nuclear power plant, pictured on May 26, 2012.

Story highlights

TEPCO says "severe accident measures" were taken in 2002, but nothing further was done

Part of the reason was a concern over spreading anxiety "in the sitting community"

TEPCO adds that the measures could also "add momentum to anti-nuclear movements"

CNN  — 

The operator of a Japanese nuclear power plant where a catastrophic accident was set off last year by a massive earthquake and tsunami acknowledged Friday that it had played down safety risks at the facility out of fear that they would lead to a plant shutdown.

The Tokyo Electric Power Company, known as TEPCO, said in a report that “severe accident measures” were taken in 2002, which included “containment venting and power supply cross-ties between units,” but additional measures were never put in place.

Read more: Japan’s nuclear fight intensifies

Part of the reason, the report said, was a concern that implementing the new safety measures “could spread concern in the sitting community that there is a problem with the safety of current plants.”

TEPCO added that taking such measures could also add to “public anxiety and add momentum to anti-nuclear movements.”

Friday’s report represents some of the operator’s most definitive language to date about its lack of preparation in protecting the Fukushima Daiichi power plant, which ultimately spewed radiation and displaced tens of thousands of residents from the surrounding area in the worst nuclear accident since the 1986 Chernobyl disaster in Ukraine.

Read more: Japan restarts first nuclear plant since Fukushima shutdown

“There was a latent fear that plant shutdown would be required until severe accident measures were put in place,” the report said. “It was possible to diversify safety systems by referencing severe accident measures taken in other countries.”

In the past year, TEPCO has come under intense scrutiny for not aggressively seeking answers to the underlining causes of what prompted the disaster.

The Japanese government said in an earlier report that the operator’s and the nuclear regulator’s actions to prepare for disasters were “insufficient,” and called the response to the crisis “inadequate.”

CNN’s Pierre Meilhan contributed to this report