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進入《TAIPEI TIMES 焦點》 Defects found at nuclear plants a threat: legislator
The Guosheng Nuclear Power Plant in New Taipei City’s Wanli District is pictured on Oct. 30, 2012. Photo: Wang Min-wei, Taipei Times
WARNING: An expert said a large earthquake could fracture pipelines inside unstable containment buildings and potentially cause a nuclear disaster
By Chen Wei-han / Staff reporter
About a hundred welding defects have been found in steel linings at the Ma-anshan Nuclear Power Plant in Pingtung County and the Guosheng Nuclear Power Plant in New Taipei City’s Wanli District （萬里） after decades of operation, with nuclear experts warning the defects could cause a radiation leak or even a nuclear disaster.
In a question-and-answer session at the legislature in Taipei on Thursday, Democratic Progressive Party Legislator Cheng Li-chun （鄭麗君） said 53 joints of the support frames inside reactor No. 1 and 54 joints inside reactor No. 2 at the Pingtung plant were wrongly welded or not welded at all, and accused the Atomic Energy Council （AEC） of negligence.
Cheng said the welding defects were first discovered during a pre-overhaul inspection of the Pingtung plant in 2013, questioning whether the structural integrity of the plant had been compromised and whether a large earthquake could shatter pipes and conduits inside the reactor.
He asked why the council and Taiwan Power Co （Taipower, 台電） — the plant’s operator — only discovered the faults 30 years after the plant started operations.
Atomic Energy Council Minister Tsai Chuen-horng （蔡春鴻） said the welding inspection was not on scheduled inspections until 2013 when similar defects were discovered at the yet to be completed Fourth Nuclear Power Plant in New Taipei City’s Gongliao District （貢寮）.
The maintenance of the reactor cores was the priority task during annual overhauls, while support frames — frames that support cables and conduits — are arranged at the periphery of the containment building and should not have significant safety implications, Tsai said, adding that the Pingtung plant had survived several large earthquakes unharmed.
In a statement issued yesterday, the council said that more than 40 similar welding defects had also been found at the Guosheng plant.
The inner surface of the nuclear reactor containment building is covered with a steel lining to reduce radiation leakage and preformed panels are installed over the lining to support frames without damaging the steel lining, the council said, adding that although some weldings were defective on the preformed panels, the structural integrity of the containment building and the strength of the support frames were not affected.
The plants have passed integrated leakage rate tests and no structural damage has been discovered, the council said, adding that it would still require Taipower to correct the problems.
However, former Institute of Nuclear Energy Research researcher He Li-wei （賀立維） said that every nuclear reactor containment building is a lifetime structure and cannot be modified in any way after the reactor starts operations.
A large-scale quake, such as the 921 Earthquake in 1999, could fracture the pipelines inside a structurally unstable containment building, leading to a breakdown of the cooling and control systems and potentially a nuclear disaster, He said.
新聞來源：TAIPEI TIMES
