Power supplier describes incident as 'minor' and below level-zero

Power supplier and experts assured the public Tuesday that there is no threat to public safety arising from an incident at Daya Bay nuclear power plant.

The nuclear leakage fear was ignited by a report from Washington-based Radio Free Asia Monday, saying that the plant experienced an abnormality in Unit 2 on May 23 resulting in the release of a large amount of radioactive iodine into the atmosphere.

Hong Kong's No 1 electricity supplier CLP Holdings, which owns 25 percent of the plant, denied the allegation. The company issued a statement saying that only a small increase in radioactive substances was found in the cooling water at the unit. The level of radioactivity has remained stable and initial assessment indicated the increase was caused by leakage from a fuel rod.

"The reactor cooling water is sealed in completely and isolated from the external environment, thus causing no impact on the public," it said.

Richard Lancaster, managing director for CLP Power Hong Kong, called the incident a minor operational matter.

He explained that the leakage took place in the heart of the nuclear reactor, which has a steel casing 200-millimeters thick and a solid reinforced concrete structure to prevent leakage of nuclear materials.

"There's no risk of leakage at all and there has been no leakage at all," he said.

He said the incident didn't even register levels high enough to meet the standard for "level zero" on the International Nuclear Event Scale. Level zero, the lowest on the scale, denotes an event without safety implications. Such an event may entail a blown fuse on an electrical circuit not related to the safety operation of a nuclear plant.

"The incident I described to you wasn't even rated as level zero," he said.

Nevertheless, the incident has been reported to China's National Nuclear Safety Administration and a Hong Kong-based consultative committee monitoring the nuclear plant has been notified, he said.

The University of Hong Kong's John Leung Kon-chong shared the view that a minor fuel rod leakage would not impact the environment, because it was contained in the reactor.

Radioactive gas was released into the atmosphere, but it poses no public health risk because concentrations are low, he said.

The Hong Kong Observatory set up a Radiation Monitoring Network (RMN) consisting of 10 radiation monitoring stations to monitor environmental radiation levels. The RMN measurement has not shown any abnormality between May 23 and June 13, according to a statement by Hong Kong's Security Bureau.

While no problems were found in the air, the observatory will check samples of food and water, John Chan, acting senior scientific officer of the Hong Kong Observatory, told Bloomberg.

"Basically if there's nothing in the air, it's unlikely we'll find high readings somewhere else," Chan said.

The Daya Bay Nuclear Power Station, located about 50 kilometers from Hong Kong, has been in commercial operation since 1994 and generates 10 billion kilowatt-hours of electricity a year for Hong Kong and Guangdong Province. The nuclear plant was operating as normally Tuesday.

China Daily

(HK Edition 06/16/2010 page1)