Unit 1 of Taiwan’s Maanshan nuclear power plant has been permanently shut down and is now undergoing decommissioning, following the expiration of its 40-year operating license.
This move aligns with Taiwan’s nuclear phase-out policy and leaves the island with only one operational reactor.
Maanshan Unit 2: The Sole Remaining Reactor
The 936 MWe pressurized water reactor (PWR) ceased operations on July 27th and formally entered the decommissioning process on July 28th. Maanshan Unit 2, a 938 MWe PWR, now stands as Taiwan’s sole remaining active power reactor.
However, its operating license is also set to expire on May 17, 2025.
Decommissioning Application and Ongoing Debate
In July 2021, the state-run Taiwan Power Company (Taipower) submitted an application to the Atomic Energy Council to decommission both units of the Maanshan plant.
Existing legislation mandates that the utility must file a decommissioning application at least three years before ceasing energy production.
The closure of Maanshan 1 occurs amidst ongoing discussions among lawmakers regarding the potential extension of the operational life of Taiwan’s remaining nuclear facilities.
Impact on Taiwan’s Energy Mix
Prior to the closure of Maanshan 1, nuclear power contributed to around 5% of the island’s energy consumption, with coal and liquefied natural gas dominating the energy mix.
Taipower has indicated that with the decommissioning of this reactor, nuclear energy’s share of power generation will drop to 2.8%.
Taiwan’s Nuclear Phase-out Policy and Referendum
In 2016, the Democratic Progressive Party (DPP) was elected in Taiwan with a platform of achieving a “nuclear-free homeland” by 2025.
This policy entailed decommissioning Taiwan’s six operational power reactors upon the expiration of their 40-year licenses. Shortly after taking office, the DPP government passed an amendment to the Electricity Act, solidifying this phase-out policy.
The government aimed for an energy mix of 20% renewables, 50% liquefied natural gas, and 30% coal.
However, a referendum in November 2018 resulted in voters choosing to repeal the amendment. Despite this, the then-Minister of Economic Affairs, Shen Jong-chin, stated in January 2019 that there would be no extension or restarts of nuclear power plants due to various factors, including strong public opposition.
Previous Reactor Closures and Construction Delays
Unit 1 of Taiwan’s oldest nuclear plant, Chinshan, was shut down in December 2018, followed by Chinshan 2 in July 2019.
The 40-year operating license for Kuosheng 1 expired in December 2021, leading to its shutdown. However, due to a lack of storage capacity in the unit’s used fuel pool, Taipower had announced in May that it could only operate the reactor until June. Unit 2 of the Kuosheng plant was subsequently shut down in March 2023.
Construction of two units at the Lungmen plant began in 1999, but the project has faced political, legal, and regulatory delays. The completed Unit 1 was mothballed in July 2015, while construction of Unit 2 was suspended in April 2014.