Liberty Times: The government announced the construction of the plant’s No. 1 reactor “will not continue,” but still go through safety checks after which it will be “sealed up,” and that the construction of the No. 2 reactor will be “suspended.” Can these measures be carried out?
Ho Li-wei (賀立維): From a technical standpoint, whether it said “will not continue,” “sealed up” or need to “pass safety inspections,” all of these are just playing word games.
Even taking another five years, or 10 years, the Fourth Nuclear Power Plant [in Gongliao District (貢寮), New Taipei City] would not be completed because it has several inherent critical issues.
An incident reported in April 2002, where the contractors were found to have used inferior steel rebar in building the No. 1 reactor’s pedestal. More than a dozen people were indicted in that case. Construction of this quality could topple in a big earthquake. Even if it did not fall, much of its piping and wiring would be stretched, ripped apart and broken. This would cause many fatalities.
When nuclear fuel rods are inserted into the reactor, there might be no major problems immediately. Maybe they would happen after a few years of operation. Because the reactor will undergo physical contraction and dilation due to temperature variations, there is also the problem of material fatigue.
When a big earthquake hits, a tiny hairline fissure may extend open into a large fracture, which would be a big disaster.
There is also a major concern over penetration of the nuclear reactor containment wall. When fuel rods start the nuclear chain reaction, the rate is about 1 million reactions per second. The heat and radiation generated are constrained by a 1m-thick wall. Around the containment building are numerous vents. If these are built with inferior materials, are shoddily constructed or are not sealed to the required thickness, then radiation could leak out.
LT: President Ma Ying-jeou’s (馬英九) administration stressed the plant’s start-up operation will depend on the result of a public referendum. If the plant was sealed up, would it be possible for operations to restart?
Ho: Taiwan’s first, second and third nuclear power plants were turnkey projects by the contractor company. For example, if General Electric had already built 100 nuclear power plants, then Taiwan was its 101st plant. The project and its testing were standardized. However, construction of the Fourth Nuclear Power Plant was divided among different contractors.
The Ma administration said that after undergoing safety inspection, the plant will be sealed up. However, without inserting fuel rods, without producing steam, without power generation and without producing radiation, how do you conduct safety inspections? At the most, the plant’s structures can be checked to see if there are plastic bottles in the cement mixture. For most of the machinery and the electrical circuits, all that can be done is “cold testing.”
Nuclear fission produces steam from water; the reactor is known as a “nuclear steam generator.” Steam is needed to generate circulation, which rotates a turbine. Without the steam, how can you do testing?
Inspection is also needed to detect possible radiation leaks. When the fuel rod is bombarded with neutrons, the nuclear fission process produces gamma-ray radiation. Fuel rods have to be inserted to make radiation detection tests meaningful and to find any leaks in the plant. The reactor’s control rod is a powerful absorber of neutrons; it acts like the brake in a car. It is to prevent neutrons from starting a chain reaction. This also cannot be checked without starting operations at the plant.