Japan assesses older nuclear plants

online.wsj.com

TOKYO--Japan is grappling with the question of whether older nuclear reactors are more prone to spinning out of control when a disaster hits, as the nation pushes to restart units for the first time since last year's accident in Fukushima.

The Japanese government, which has held a series of hearings on the matter this year with an expert panel, concluded age wasn't a factor in the meltdown of three reactors at the Fukushima Daiichi plant following the devastating earthquake and tsunami in March 2011. All three reactors went online in the 1970s. The government said bolts, pipes and other important parts used in safety equipment such as cooling systems had been regularly replaced, making the age of the reactors less relevant.

A number of critics have expressed concern with the findings, saying that the government's investigations weren't broad enough, and that it ignored comments even from critical members of the panel. The government has been pressing to avert expected energy shortages over the summer by restarting some of Japan's 50 reactors, nearly all of which are now shut down while it reviews their safety. Some 60% of those reactors started operations in the 1970s or 1980s--a similar proportion to that seen globally.

On Wednesday, the government said it expects electricity shortages in Tokyo as well as in the Kansai and Kyushu regions this summer, which is shaping up to be the country's first peak-demand season without nuclear power since 1965. nuclear power generated 11% of Japan's power supply this past August, according to industry data. The loss of that power makes the potential for shortages greater this year than last, despite efforts by utilities to boost non-nuclear generation.

In a preliminary report, the government's national policy unit projected a 5% shortage for Tokyo and 4% shortages for Kansai and Kyushu. The forecast is based on data from last summer and on supply-capacity figures submitted by utilities. It takes into account the possible resumption of power-saving programs in place last summer, which were estimated to have trimmed typical demand levels by around 10%.


Read More…