‘Big One’ will halve Tokyo power supply

Disaster panel details hazards of feared quake


A massive earthquake in Tokyo will heavily damage its power, telecommunications and waterworks infrastructure and cut off electricity to half of the people served by Tokyo Electric Power Co., the government’s disaster panel estimates.

In response to the extensive damage projected, utilities and other firms responsible for maintaining vital social infrastructure are coordinating with local governments to prepare for the long-dreaded Big One hitting Tokyo.

The tremors will force the capital’s thermal power plants to be suspended in rapid succession, depriving some 12.2 million Tepco customers of power, according to the Central Disaster Management Council.

As a result, troubled Tepco’s capacity is expected to fall to about half of what it needs in the summertime, when demand usually peaks at over 50 million kw, even if electricity procured from other utilities is included.

This brings up the problem of Japan’s quirky bipolar transmission frequencies. Since the electricity frequency is 50 hertz in eastern Japan and 60 hertz in the west, only 1.2 million kw can be transferred between the two regions. That’s enough to be generated by a single nuclear reactor.

A plan is under way to boost the conversion capacity to 2.1 million kw by fiscal 2020, but cross-region transfers will only have a limited effect in alleviating power shortages in Tokyo.

Failure to quickly repair damaged or shut-down thermal plants will force the capital to resort to the same rolling blackouts put into use after the March 2011 Great East Japan Earthquake disrupted power supply in Tokyo.

The panel recently issued a report stating that there is a 70 percent chance of an earthquake with a magnitude of around 7 hitting the Tokyo metropolitan area “in the next 30 years.” The report echoes similar reports with similar probabilities issued nearly 30 years ago that never state when the 30-year period begins and ends.

The University of Tokyo said in 2012, however, that the chances of a magnitude-7 quake hitting the capital are 70 percent in four years and 98 percent in the next 30 years.

Petroleum products such as gasoline have already been set aside as part of national and private stockpiling efforts, but the panel predicts that a disaster will trigger a surge in demand for gas and diesel oil for emergency transportation purposes, as well as for kerosene for heating use. In the meantime, supply of the fuels would be held up by transportation havoc as the blackout renders refueling impossible.

In the wake of March 2011, NTT East Corp. established a fuel-storage facility for power generators to ensure that government communications will continue working for at least six days even amid an outage.

On the first day of any disaster, fixed-line and mobile phone communications will be nearly nonexistent to the public because of blackouts, cable damage and carriers’ emergency restrictions on phone use.

Mobile phone email will likely see long delays, but social networking applications, such as Facebook and LINE, are likely to function as usual.

An official at NTT Docomo Inc. mostly concurred.

“There will be no problem with text communications on social networking sites, but we call for user restraint on video viewing because that would flood and disable the lines.”

In the immediate aftermath however, as many as 14.4 million residents mainly in central Tokyo might lose access to water.

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