A top nuclear industry executive has called for priority to be given to nuclear power as China's power supply, ensuring that nuclear power plants are a primary source and their output is not adjusted to meet fluctuations in demand.

He Yu, chairman of China General Nuclear Power Corp, also suggests further construction and usage of a connected patchwork of grids across provinces and regions to ensure the consistent supply of the clean energy.

"Not given full play, nuclear reactors are constantly and sometimes consistently shut down like other power units, when the region's electric grid is at or beyond capacity," said He, who is attending the annual session of the National Committee of the Chinese People's Political Consultative Conference.

"The country has set strict security measures for nuclear development, which means that the sector requires more investment while nuclear projects require a longer construction period."

China's power-generation showed signs of a glut as early as 2013 before hitting a high in 2015, and overcapacity is likely to continue for another five years as demand growth slows, according to IHS Market Inc.

Many of the plants are going to be much less utilized than what they had initially been planned for, despite the growing power demand, it said.

China had 35 nuclear power reactors in operation with a total installed capacity of 33.6 GW by the end of 2016, accounting for 2 percent of the country's overall installed electricity capacity, said He.

China added about 8 GW of nuclear power capacity last year, boosting its installed capacity to about 34 GW, according to BMI Research, which provides macroeconomic, industry and financial market analysis.

Nuclear power is expected to reach 58 GW by the end of the decade, the National Development and Reform Commission said in December in its 2016-20 development plan for the power industry.

He said China wasted a total 46.2 billion kilowatt-hours of power last year, a waste of 19 percent as its power industry was capable of generating 242.8 billion kilowatt-hours that year.

The suspension of nuclear reactors also leads to a waste of uranium resources, the reactor fuel, while increasing the difficulties and cost of nuclear waste disposal, he said.

He said many countries, including the United States, Russia, the United Kingdom and South Korea, are taking nuclear power as a baseload supply, and none of them would have their reactors suspended when there are fluctuations in energy demand.

"Nuclear energy plays an irreplaceable role in China's energy security, helping to reduce air pollution caused by coal-fired power generation," he said.

"China's energy sector has been dominated by coal, accounting for 64 percent of primary energy use, far above the global average of around 30 percent,"

The government has vowed to make renewable energy play an integral role in sustainable development, boosting the amount of non-fossil energy to 15 percent by 2020 and 20 percent by 2030, with coal consumption reduced to 62 percent of energy use by 2020.

Wang Binghua, chairman of State Power Investment Corp, and Wang Shoujun, president of the State-owned China Nuclear Engineering Group Co, who are also attending the annual session of the CPPCC National Committee, also called for nuclear power plants to be a primary source of energy supply.

An analyst said nuclear energy are not supposed to be shut down due to fluctuations in energy demand.

"It is far from ideal not to maximize the loads of nuclear reactors, as the general traditional convention or view is that it is not good to lower and then raise the load factors for nuclear reactors frequently from a safety perspective," said Joseph Jacobelli, a senior analyst with Asia utilities and infrastructure research at Bloomberg Intelligence.