Daya Bay more modern, safer than Fukushima, says nuclear expert

PUBLISHED : Thursday, 17 March, 2011, 12:00am
UPDATED : Monday, 03 October, 2016, 5:52pm

The Daya Bay nuclear power plant in Guangdong has a better design than the troubled plants in Japan, which should give Hong Kong and mainland authorities more time to cope with the risk of radiation leakage in a Fukushima-like nuclear crisis, a nuclear specialist said.

Although nuclear plants in Fukushima and Daya Bay were all broadly categorised as second-generation technology, the Hong Kong-area plant had stronger layers protecting the reactors, Professor Woo Chung-ho of Polytechnic University said.

Authorities would therefore have more time to handle the possible risks of explosions and the spread of radiation, he said.

Hong Kong is 60 kilometres from the Daya Bay plant and imports 70 per cent of its output.

'As the containment walls of the Daya Bay reactors can stand much higher pressure than those at Fukushima, it would take longer for the steam and hydrogen accumulating inside reactors to explode,' Woo said.

The Daya Bay plant, developed in the 1970s with French technology, uses pressurised water to carry away the heat generated from the reactors to the steam generators. In order to cope with the pressure, the reactors' protective layers are at least twice the thickness of those in the Fukushima plant, which uses US technology from the 1960s.

The new nuclear station in Lingao, built next to the existing plant in Daya Bay and operating since 2002, is categorised as second-plus generation with improved technology.

The reactors in Fukushima have in operation for 40 years. Those in Daya Bay, 17 years.

With the protective layers of at least two reactors in Fukushima presumed damaged, there were questions in Hong Kong yesterday about the possible spread of radiation.

'I don't think Hongkongers should panic at this stage, given the favourable wind direction,' Woo said. 'If we really need to do something, we should take this chance to improve the accountability of the nuclear power company.'

Secretary for Security Ambrose Lee Siu-kwong said in a legislative meeting that the city was unlikely to suffer an accident similar to Japan's.

'First of all, the chance of Daya Bay being hit by a massive earthquake is very low,' he said. 'Moreover, the design of the nuclear plant in Daya Bay is different from the one in Japan. And I believe that the Daya Bay plant will learn a lesson from the Japanese incident.'

Lee said there was a contingency plan for the city in the event of an accident happening at the plant. This information was available on the Security Bureau website.

'And there are rescue and evacuation exercises held in MTR and other government organisations,' he said. 'Do we need an exercise for the whole community? We will discuss it later to see if we really need it.'

Yuan Xilu , deputy director general of the department of development planning under the National Development and Reform Commission, said the nuclear power plant crisis in Japan would serve as an alert for countries using nuclear energy.

'But the broad direction of raising the proportion of nuclear energy in the nation's electricity supply will remain unchanged,' he said. 'The long-term strategy was decided after lengthy discussion and studies.'

The mainland has 13 nuclear power reactors in operation and more than 25 under construction.

Yuan said newly built nuclear plants on the mainland adopted third-generation technology, which would help them avoid the problems experienced in Japan.

The troubled Japanese reactors used man-made power sources, such as diesel engines, to pump water to cool the reactors. Third-generation reactors used forces like gravity to deliver water automatically.