Japanese officials say they're reviewing suspiciously high radiation measurements around the Fukushima Daiichi nuclear plant, while the U.S. military has been called in to help with a final intensive search for bodies from the March 11 tsunami and earthquake.

The Nuclear and Industrial Safety Agency said Friday that measurements released on the previous two days — including one that indicated radiation in groundwater was 10,000 times the government's standard — seemed suspiciously high.

TEPCO workers experimentally spray adhesive synthetic resin over the ground at the power plant to prevent the spread of radioactive material. (TEPCO/Associated Press )

Tokyo Electric Power Co. (TEPCO) has repeatedly made mistakes in analyzing radiation levels, and the nuclear agency said it is considering a review of all radiation data collected since the tsunami.

The uncertainty has fuelled fears that the health risks are being downplayed, and cast doubt on the company's ability to respond effectively to the crisis. TEPCO has not been able to stabilize the plant's dangerously overheating reactors since cooling systems were knocked out in the tsunami.

Among the measurements called into question was TEPCO's groundwater reading on Thursday, said Hidehiko Nishiyama, a spokesman for the Japanese safety agency.

Seawater and air concentrations from this week also are under review, he said.

"We have suspected their isotope analysis, and we will wait for the new results," Nishiyama said, adding that the agency thinks the numbers may be too high.

TEPCO has conceded that there appears to be an error in the computer program used to analyze the data and that recent figures may be inaccurate. The company has indicated they are probably too high, but has also said that the figures may be correct, despite the glitch.

The safety agency has suggested it might order a complete review of all radiation data collected since a March 11 tsunami disabled the plant.

Though the size of more recent leaks is now unclear, it appears radiation is still streaming out of the plant, underscoring TEPCO's inability to get it under control. The company has increasingly asked for international help in its uphill battle to keep reactors cool.

A U.S. construction company is currently retrofitting two gigantic pumps — described as the largest such equipment in the world — to send to the stricken plant next week.

They will initially be used to pump water to try to cool damaged reactors, but are also capable of pumping concrete, should a decision to entomb the reactors be made.

The company, Wisconsin-based Putzmeister America Inc., made similar machines that were used to encase the site of the Chornobyl nuclear disaster in 1986 in concrete.

On Friday, TEPCO workers sprayed 400 litres of a resin solution near the No. 4 reactor to prevent the spread of radioactive materials by wind and rain. About 60,000 litres of the resin, which solidifies into a coating, will be sprayed over a period of two weeks if the procedure is judged a success, Kyodo News reported.

Search for bodies intensified until Sunday

Japanese and U.S. military ships and helicopters trolled the coastline looking for bodies Friday, part of an intensive three-day search to find those swept out to sea nearly three weeks ago.

Altogether, 25,000 soldiers and members of Japan's Self Defence Forces, 120 helicopters, and 65 ships will continue searching through Sunday. If U.S. forces spot bodies, they will point them out to the Japanese military rather than try to retrieve them.

So far, more than 11,700 deaths have been confirmed, and more than 16,000 are still missing after the disaster, which officials fear may have killed some 25,000 people.

Many bodies swept out to sea may never be found. Public affairs official Yoshiyuki Kotake said search activities would be more limited after this Sunday.

During Friday's search, 32 bodies were recovered.

Concern for groundwater contamination

Seiki Kawagoe, an environmental science professor at Tohoku University, said radioactive substances were unlikely to contaminate drinking water.

But there are two ways radioactivity could eventually affect drinking water if concentrations were high enough.

The other concern is that contaminated water from the plant could seep into underground waterways and eventually into rivers used for drinking water. Tomohiro Mogamiya, an official with the Ministry of Health, Labour and Welfare's water supply division, said that was "extremely unlikely" since groundwater would flow toward the ocean, and the plant is right on the coast.

Members of the Japan Self-Defence Force carry the body of a victim found amid the rubble in Noribu, northern Japan, Thursday. (Carlos Barria/Reuters)

There are two nearby filtration plants for drinking water, and both have been shut down because they are just inside the exclusion zone. One takes water from the Kido River, to the south, and another takes it from groundwater below Odaka, to the north. Both are several kilometres from the coast, and therefore on higher ground.

"When people return to the area we will test the water to make sure it is safe," said Masato Ishikawa, an official with the Fukushima prefecture's food and sanitation division.

Evacuees frustrated

Radiation concerns have rattled the Japanese public, already struggling to return to normal life after the earthquake-borne tsunami pulverized hundreds of kilometres of the northeastern coast.

Three weeks after the disaster in one of the most connected countries in the world, 260,000 households still do no have running water and 170,000 do not have electricity.

Hundreds of thousands more people are living in evacuation centres, most because they lost their homes in the tsunami. But others have been forced to leave their houses near the plant because of radiation concerns.

Rescue workers sail a boat past stranded ships in Kesennuma, Miyagi prefecture, Thursday. (Damir Sagolj/Reuters)

Residents, angry with the slow progress of the effort, have started violating evacuation orders around the plant and are sneaking back to gather belongings from their homes.

Fukushima officials have put up posters in all evacuation centres urging residents not to violate the cordon, but are also urging the government to organize group trips for people.

"There is no doubt in my mind that it is dangerous in there," said Kazuko Hirohara, a 52-year-old nurse from Minami Soma. "I just wish they would have thought about safety before they ruined our lives."