Wed, Jun 27, 2012 - Page 8 News List

Cracks in nuclear policy beg questions

By Pan Han-shen 潘翰聲

In the past, the power load at Taiwan’s nuclear power plants was diminished when a tropical storm or typhoon approached to avoid any negative weather impact on the plants. However, when Tropical Storm Talim neared Taiwan last week, the No. 1 reactor at the Guosheng Nuclear Power Plant in Wanli District (萬里), New Taipei City (新北市), was instead reactivated the night before the storm arrived. Why the rush to reactivate?

Early last month, I was invited to attend a public hearing organized by the legislature’s Education and Culture Committee to discuss the broken anchor bolts at the No. 1 Guosheng reactor. After the report on the anchor bolt investigation was made public, it had been reviewed by Wu Cheng-chung (吳政忠), a professor in the Institute of Applied Mechanics at National Taiwan University, and other experts. They found that in addition to the seven broken bolts, there were also 29 cracked bolts. Despite this, the Atomic Energy Council (AEC) decided that the reactor could safely operate for another 18 months.

Later, it was also discovered that two of the nine welds on the same reactor’s core shroud had developed cracks and that these cracks had been expanding, from 20cm to 30cm long. The AEC then made a hasty decision to allow the reactivation of the No. 1 reactor. The government said that the same thing happens to boiling-water reactors in other countries, but actually when a similar problem occurred at a power plant in Germany, it was decided that the plant should be scrapped. In Japan, a nuclear disaster occurred at the Fukushima Dai-ichi power plant, where cracks in the core shroud had existed for decades. Who will take responsibility if that kind of disaster happens here?

Imagine that a visual inspection of an aircraft reveals that seven of the bolts holding the engines in place have failed. Common sense dictates that they should be replaced immediately. Then imagine that further inspection reveals that 30 percent of all the engine’s bolts are cracked, and while passengers are clamoring to have all the bolts replaced, it is also discovered that the cracks in the engine block have expanded. However, the captain just says: “We have held these cracks together with big clamps over the past few years, so I can guarantee that flying back will not be a problem,” and the airplane takes off. That is basically what is happening at the Guosheng plant.

At the public hearing, the AEC was extremely displeased with Taiwan Power Co’s (Taipower) report and said that “this is not a root cause analysis.” A real root cause analysis would not merely point out why the anchor bolts are so brittle that they cannot withstand a blow, but rather why the reactor was vibrating so violently when it was shut down — it would show the origin of the force that caused the blow that cracked the bolts. If earthquake instruments 5m outside the reactor measured vibrations of 0.29G, and an extrapolation of that value shows that vibrations inside the reactor could be as high as 2.4G, then what the public really would like to know is why Taipower and the AEC waved the incident away by saying the measuring equipment was faulty.

The government casts anti-nuclear activists as emotional and lacking in expertise, but when government officials themselves come under pressure, they also resort to various unprofessional and unscientific explanations. If we cannot determine why the core shroud has cracked, and since there is a power redundancy of 20 percent to 30 percent even during peak use hours, then one cannot help wondering why the government was in such a hurry to reactivate the reactor at Guosheng in the middle of a tropical storm. It would be interesting to hear the government give a civilized explanation for this.

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