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Japan to Restart Nuclear Reactors

Restart of Oi reactors ends country’s nuclear hiatus

2 min read
Japan to Restart Nuclear Reactors

The Japanese government Saturday ordered the restart of the1.18-gigawatt reactors 3 and 4 at the Oi nuclear plant in Fukui Prefecture, central Japan. The decision came just a couple of hours after Fukui governor Issei Nishikawa travelled to Tokyo to give his approval. Japan has been without any nuclear power since 5 May when the last of some 50 active reactors was shut down to undergo inspections and stress tests in the wake of the 11 March earthquake last year.

It took concerted government and utility lobbying to persuade Fukui local and prefectural government officials that reactivation was both necessary and safe. Nishikawa also spelled out preconditions to be met before he was willing to agree. The preconditions revolved around safety concerns, in particular the acquisition of local agreement on the restart and a public reassurance from the prime minister that the reactors were safe.

Pressured by business groups, Prime Minister Yoshihiko Noda held a press conference 8 June to stress the need to restart the reactors to prevent power shortages and likely social and business disruption. He said the nuclear industry had learned from the Fukushima nuclear accident. Kansai Electric Power Co. (KEPCO), the operator of the Oi plant, had instituted new government-ordered safety measures and was implementing others under deadline, including building a higher seawall to protect against tsunami, he told reporters. “By making maximum use of the knowledge gained so far,” said Noda, “we have confirmed that even if the nuclear power station was to lose all of its (conventional) sources of electricity, the reactor cores would not be damaged.”

Following Noda’s public appeal, the Fukui government’s own nuclear safety committee submitted a report endorsing KEPCO’s safety measures, while the mayor of Oi town, Shinobu Tokioka, also approved of the restart.  These events made it a relatively easy matter for the Fukui governor to give his consent, despite strong anti-nuclear opposition, which fears the restart will open the way to reactivation of the other twenty or so idled reactors, which like the two Oi reactors, have already passed their stress tests.

“But it’s impossible to restart the reactors immediately,” points out professor Keiji Miyazaki of the Osaka Science and Technology Center. He says it will take roughly two weeks to clean water and pipes in the No. 3 reactor system of impurities, to remove any unwanted air and to test valves and equipment. Then, after firing up Unit 3, “it will take a few days to gradually power it up (after which) the process must be repeated for Unit 4,” says Miyazaki. KEPCO says full output could be reached as early as 24 July.

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Smokey the AI

Smart image analysis algorithms, fed by cameras carried by drones and ground vehicles, can help power companies prevent forest fires

7 min read
Smokey the AI

The 2021 Dixie Fire in northern California is suspected of being caused by Pacific Gas & Electric's equipment. The fire is the second-largest in California history.

Robyn Beck/AFP/Getty Images

The 2020 fire season in the United States was the worst in at least 70 years, with some 4 million hectares burned on the west coast alone. These West Coast fires killed at least 37 people, destroyed hundreds of structures, caused nearly US $20 billion in damage, and filled the air with smoke that threatened the health of millions of people. And this was on top of a 2018 fire season that burned more than 700,000 hectares of land in California, and a 2019-to-2020 wildfire season in Australia that torched nearly 18 million hectares.

While some of these fires started from human carelessness—or arson—far too many were sparked and spread by the electrical power infrastructure and power lines. The California Department of Forestry and Fire Protection (Cal Fire) calculates that nearly 100,000 burned hectares of those 2018 California fires were the fault of the electric power infrastructure, including the devastating Camp Fire, which wiped out most of the town of Paradise. And in July of this year, Pacific Gas & Electric indicated that blown fuses on one of its utility poles may have sparked the Dixie Fire, which burned nearly 400,000 hectares.

Until these recent disasters, most people, even those living in vulnerable areas, didn't give much thought to the fire risk from the electrical infrastructure. Power companies trim trees and inspect lines on a regular—if not particularly frequent—basis.

However, the frequency of these inspections has changed little over the years, even though climate change is causing drier and hotter weather conditions that lead up to more intense wildfires. In addition, many key electrical components are beyond their shelf lives, including insulators, transformers, arrestors, and splices that are more than 40 years old. Many transmission towers, most built for a 40-year lifespan, are entering their final decade.

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