The Jinshan reactor 2 goes offline with a transmission line collapse.
The last remaining operational nuclear reactor in Northern Taiwan – Jinshan Nuclear Power Plant (NPP 1) reactor 2 – was automatically shut down after one of the main transmission line towers at the plant collapsed during torrential rains on June 3. Taiwan Power Co. (Taipower) spokesman Frank Lin said in an interview that the reactor will remain offline indefinitely until an investigation reveals more details about the cause of the collapse.
When the tower went down amid a severe downpour that dumped some 500 millimeters of rain on the area, it triggered an automatic shutdown procedure. Lin emphasized that the shutdown was a safeguard built into the system and that the reactor was not at risk.
“The transmission tower collapse caused the reactor to automatically trip – it’s a safety protection mechanism,” Lin explains. He adds that Taipower will inspect all of the transmission line towers to ensure that the incident is not repeated.
The impact of the reactor shutdown will have minimal impact on Taiwan’s power supply. Jinshan NPP 1 is composed of twin 636-megawatt (MW) reactors, each generating some 1.5% of Taiwan’s total power needs. But Jinshan reactor 1 (Jinshan-1) had in 2014 sparked safety concerns. The Legislative Yuan has declined to authorize the reactor’s restart, even though the Atomic Energy Council (AEC), the nation’s regulatory body for nuclear power, has given its okay.
Meanwhile, Jinshan-2 – which is licensed to operate until June 15, 2019 – was scheduled for shutdown on June 10, only a week after the incident, since lack of space in the cooling pools prevents the reactor from being refueled.
The unit could conceivably be started up again if Taipower is able to shift some of the spent fuel to dry cask storage. Facilities for dry cask storage at Jinshan NPP 1 and Kuosheng have already been constructed by Taipower and approved by the AEC and the Environmental Protection Administration, but the New Taipei City government has refused to let them become operational. Without clearing space in the cooling pools, the spent fuel in the reactors cannot be unloaded and replaced with fresh fuel, effectively necessitating a shutdown.
Taiwan has three functional nuclear power plants: Jinshan NPP 1, Kuosheng NPP 2, both located in New Taipei City, and Maanshan NPP 3, located in southern Taiwan’s Pingtung County. Construction of the controversial Longmen NPP 4 was never completed and successive Taiwan governments have continued to mothball the plant. With the shutdown of Jinshan-2, northern Taiwan currently has no operating nuclear power reactors, while only reactor 1 at Maanshan is in operation, as Maanshan-2 is temporarily offline for refueling.
Nuclear energy at the moment supplies just 3% of Taiwan’s total electricity needs, down from 4.5% before the shutdown of Jinshan-2, and a sharp decrease from the 19% in 2014, according to Taipower data.
Fossil fuels at present supply some 90% of Taiwan’s total power needs, of which 40% is fueled by coal, 44% by natural gas, and the rest mostly oil and a small proportion of diesel.
The ruling Democratic Progressive Party has long vowed to eliminate nuclear power from Taiwan, and the nation’s Electricity Act has been amended to require that all nuclear power operations cease by 2025 when Maanshan-2 is scheduled to be retired. But while the government initially said that each reactor will be operated through to the end of its licensure, for most of them that is unlikely to be the case.
Both of the 985MW reactors at Kuosheng are currently offline. Kuosheng-2 was taken offline on May 30, 2016, after a fire in a cable forced the reactor to shut down. As with Jinshan-2, the AEC has investigated the incident and approved a restart, but the Legislative Yuan has withheld its consent.
Yet even if Kuosheng-2 and Jinshan-1 were restarted immediately, neither would be likely to continue operating until the end of its licensure due to the lack of storage capacity for spent fuel.
Spent fuel cooling pools are located within the reactor housing and are designed as short-term storage for an expected five years. However, as no midterm storage has been permitted in Taiwan, the cooling pools have in fact become long-term storage. Fuel in the Jinshan power plant cooling pools dates to the late 1970s, while the Kuosheng cooling pools began accumulating spent fuel in the early 1980s.
Taipower is in the process of renovating the loading pool at Kuosheng-2, which is currently offline due to the saturation of its cooling pools, in a move to make refueling possible. Normally the purpose of a loading pool is to allow spent fuel to be unloaded for transport to medium-term storage (which has never happened in Taiwan). Last August, Taipower applied to the AEC for permission to convert the loading pool to spent fuel storage pools. The application was finally approved in April and the construction phase of the NT$300 billion project has already been completed. The construction must be inspected and approved by the AEC before a restart can occur, followed by further approvals before the reactor can start generating power.
According to Lin, Taipower submitted its application to the AEC to restart Kuosheng-2 on June 1. Taipower hopes that the 985MW reactor will be back online by the end of June, although that development could yet be stymied by the Legislative Yuan. New Power Party (NPP) Legislator Huang Kuo-chang was joined by environmental groups in raising questions recently regarding the approval process of the project and has demanded that it be halted.
Meanwhile, the refueling process at Maanshan-2 will be completed before the end of the month, which will raise nuclear power’s total share of Taiwan’s power generation to 6%.