* Chinese nuclear power expansion slowed after Fukushima
* First AP1000 due to start late 2017, 4 yrs behind first timeline
* As others withdraw, China could become nuclear power leader
* CNNC remains interested in taking stake in France's New Areva
By Chen Aizhu
BEIJING, March 17 (Reuters) - China needs to speed up building planned nuclear reactors and make quick new approvals over the next few years to meet a target for 2020 and keep projects rolling beyond that, an ex-chairman of China National Nuclear Corporation said.
CNNC aims to start up around November this year - nearly four years behind an original timeline - the world's first Westinghouse AP1000 reactor, said former chairman Sun Qin in an interview this week.
China currently operates 35 nuclear reactors, which supply 3 percent of China's total power use, and it is building another 31 units as part of an ambitious programme to put a total of 58 gigawatts into operation by 2020.
Several former top nuclear powers, including Germany and Switzerland, announced plans to withdraw from the sector in the wake of Japan's Fukushima nuclear disaster of 2011, the world's worst since Chernobyl. With Japan and the United States also scaling back on nuclear, China could emerge in the next decade as the most significant developer of nuclear-fired power if it accelerates its building schedules.
"The successful start-up of AP1000 will boost industry morale ... and will be replicated along the coast as we've planned a series of both AP1000, and (Areva's) EPR reactors," Sun said.
Delays at so-called third-generation reactors, both the Westinghouse AP1000 and French state firm Areva's European Pressurised Reactor (EPR), have dragged on China's pace of nuclear power development for the past few years, after Beijing had already suspended new project approvals for three years following the Fukushima meltdowns.
At the world's maiden AP1000 project in the eastern province of Zhejiang, developed by Westinghouse and its struggling Japanese parent Toshiba, delays for the fine-tuning of designs have inflated costs of the first two reactors by at least 10-20 percent, said Sun, who retired last December after working in the industry for over 30 years.
Sun didn't give the initial cost estimates, but state media reported in 2009 the first two reactors then cost 40 billion yuan ($5.8 billion).
Beijing will need to approve six to eight new reactors a year between 2018 and 2020, to accelerate post-2020 development, said Sun, adding that another slowdown would waste China's recently developed nuclear equipment manufacturing capacity.