CLP should have immediately reported the incident. But even after it was exposed, the company chose to inform only a handful of news organisations and excluded those from the electronic media. Obviously, it was a damage-control measure as it tried to minimise news coverage and draw less public attention.

Chan Siu-hung, CLP corporate development director, described the leak as minor and said the company had not disclosed it immediately because it was insignificant.

The incident was classified as a level one accident on the scale of 0-7 set by the International Atomic Energy Agency. Only nuclear reactor accidents classified as level two or above are required to be reported to the public and international organisations immediately. Chan seems to believe that the company doesn't need to do more. This kind of attitude is unacceptable.

With Daya Bay located about 50 kilometres north of Hong Kong, many Hongkongers have been concerned about the risks of having a nuclear power plant located close by.

Before the plant was built in the 1980s, one million people signed a petition to try to block its construction, citing safety and environmental issues and the rights of Hong Kong residents. Many are now suspicious of the company's reporting system because it doesn't have to report all incidents.

Since 2000, there have been 15 level one nuclear incidents at the plant, the last in January 2007. If there were, say, significant radioactive leakage and the wind was blowing southwards, in our direction, the whole of Hong Kong would be affected.

Nuclear power is the cleanest form of energy available. It brings enormous benefits, as well as risks to people and the environment. The amount of ionising radiation the human body can withstand a year is equivalent to receiving 100 chest X-rays.

Some research studies have shown that, even without any leakage, workers at a nuclear power plant have a higher risk of dying from leukaemia or other types of cancer. The fact is the health effects of exposure to radiation in various forms as well as proximity to nuclear plants are extremely frightening. No nuclear incident is too minor to warrant reporting.

Besides Daya Bay, there is the Ling Ao nuclear power plant, which is located in Longgang district in Shenzhen, some 69 kilometres north of Hong Kong, and fully owned by the central government. And, our government is planning to build another nuclear plant in Guangdong.

There is no such thing as a safe nuclear plant. We can have all the safety measures in place, but we cannot remove the possibility of human error. Therefore, we need the government to implement a stricter monitoring system and a more transparent reporting mechanism.

The Daya Bay plant is 75 per cent owned by the Guangdong government, which appears to believe that reporting minor nuclear incidents would only cause unnecessary panic. It seems to have forgotten that Hong Kong buys 70 per cent of its supply and, being the major consumers, we have the right to information.

We need to remind our officials to be more vigilant in future and keep pressing for full disclosure of all incidents. Before we see any tangible improvement in the management of Daya Bay, we may need to shelve all future plans to build new nuclear plants.

Albert Cheng King-hon is a political commentator