Updated 8.55am

THE OPERATOR OF the Japanese Fukushima nuclear plant is considering bailing water out of the reactors as radiation is so high, Reuters reports.

Three workers at the plant were exposed to high levels of radiation on Thursday, officials reported. It has now emerged that they were exposed to 10,000 times the amount of safe radiation.

This could mean that the crucial containment vessel for nuclear fuel has been ruptured, which in turn could signal a serious reversal after days of progress in containing radiation leaks.

“The contaminated water had 10,000 times the amount of radiation as would be found in water circulating from a normally operating reactor,” Reuters reports Japanese nuclear agency official Hidehiko Nishiyama as saying.

“It is possible that there is damage to the reactor.”

Two Japanese travellers who arrived in China from Tokyo have been hospitalised after being found to have ‘severe’ radiation levels.

ABC News reports that China’s general administration of quality supervision, inspection and quarantine said that the two were found to have radiation levels that “seriously exceeded limits” when they arrived in the city of Wuxi in Eastern China on Wednesday.

However, according to China’s customs body, the duo do not present a risk to others.

Japanese nuclear safety officials said today that they suspect that the reactor core at one unit of the troubled FukushimaDai-ichi nuclear power plant may have breached, raising the possibility of more severe contamination to the environment.

Hidehiko Nishiyama, a spokesman for the nuclear safety agency, commented that it is possible that somewhere at the reactor may have been damaged but their data suggests the reactor retains certain containment functions, implying that the damage may have occurred in Unit 3′s reactor core but that it was limited.

Officials say the damage could instead have happened in other equipment, including piping or the spent fuel pool.

This reactor is perhaps the most troubled at the six-unit site, and holds 170 tons of radioactive fuel in its core.

Although previous radioactive emissions have come from intentional venting of small amounts of steam to prevent the core from bursting, releases from a breach could allow uncontrolled quantities of radioactive contaminants to escape.

Operators stopped work Friday at units 1 through 3 to check on radiation levels.

Meanwhile, radioactive contamination has been found in vegetables grown near the Fukushima plant.

Singapore’s Agri-Food and Veterinary Authority said that it found small levels of contamination in samples of Japanese mustard, parsley and two other plants imported from the prefectures of Tochigi, Ibaraki, Chiba and Ehime.

However the levels of radioactive contamination were small enough that the short-term consumption of those foods wouldn’t pose a health hazard.

The AVA has added food imports from Chiba and Ehime to a ban already in place on the sale of milk, milk products, fruits, vegetables, seafood and meat from Fukushima, Ibaraki, Tochigi and Gunma prefectures.

- Additional reporting by AP