Japan nuclear plant operator missed inspections

Japan's nuclear safety agency says the operator of the country's troubled nuclear complex repeatedly failed to make crucial inspections of equipment in the weeks before it was crippled by the earthquake and tsunami.

In a report released nine days before the disasters, the agency criticised Tokyo Electric Power Company for not inspecting 33 pieces of equipment at the Fukushima Dai-ichi plant.

Among the machinery the utility missed were back-up generators, pumps and other parts of cooling systems which the tsunami later swamped, leading to the plant's overheating and the release of radioactive gas.

Even before the crisis, Tokyo Electric has been the target of criticism for maintenance lapses at its plants.

In the aftermath of the disaster the safety agency has pointed to one mistake - backup generators were stored in the basement and so were easily swamped.

Utility companies often skip inspections because they do not want to take equipment offline outside of scheduled maintenance periods. Nuclear safety officials have declined to say that the failures in the report or the location of the backup generators contributed to the current crisis.

"For now, we cannot immediately link this to the latest accident. We still have to wait for thorough investigation after we manage to settle the crisis," an agency official said.

Overall the report adds to a disturbing catalogue of safety, maintenance and other lapses by Tokyo Electric, Japan's wealthiest utility with influence over the safety agency that is supposed to regulate it.

The safety agency report was a follow-up for other Tokyo Electric transgressions. Another nuclear plant run by the utility, Kashiwazaki Kariwa, experienced previously what was one of Japan's worst nuclear accidents, when an earthquake in 2007 caused malfunctions - fires, burst pipes, leaks of radioactive water spills - and led to at least eight deaths.

After Tokyo Electric missed 117 inspections at Kashiwazaki, the nuclear safety agency late last year ordered it to conduct a company-wide review of its inspection systems. In response, Tokyo Electric reported that it skipped 54 separate inspections, the 33 at Fukushima Dai-ichi - whose Unit 1 is one of Japan's oldest reactors in operation - and the rest at the nearby Fukushima Daini. The latter plant shut down and was quickly brought under control after the earthquake and tsunami.

The March 2 report said that the missed inspections did not present an immediate risk to safety and gave Tokyo Electric until June 2 to respond.