The May 23 event at Daya Bay Nuclear Power Station was a minor operational incident with no effect on public safety, public health or the environment, Secretary for Security Ambrose Lee says.

He told legislators today the low-level incident meant the Hong Kong Nuclear Investment Company did not activate the notification mechanism. He said the current notification mechanism is effective; however, it will be reviewed to strengthen co-ordination between concerned parties.

"There are two aspects of the current notification mechanism. On one hand, the operator of the power station will notify the company of any licensing operational event. The company submits monthly reports of licensing operational events to its board members, which include representatives of the Environment Bureau and the Security Bureau. The company also uploads such information on its website for the public's reference.

"On the other hand, the Hong Kong Government and Guangdong authorities have established an official notification channel. In case of a contingency event or accident at the plant, the power station operator will inform Guangdong [authorities] immediately. The office will notify Hong Kong authorities in accordance with the contingency notification arrangements agreed between the two sides."

The Daya Bay Nuclear Power Operations & Management Company has formed an expert group to investigate the incident. The Government will monitor the situation.