June 15 (Bloomberg) -- China’s Daya Bay nuclear power plant had a “very small leakage” from a fuel rod last month that has been contained, CLP Holdings Ltd., Hong Kong’s biggest electricity supplier, said in a statement.

A “small increase” in radioactive substances were detected in cooling water at the plant’s Unit 2 on May 23, according to the statement sent today. “The reactor cooling water is sealed in completely and isolated from the external environment, thus causing no impact to the public,” it said.

is located 50 kilometers (31 miles) from Hong Kong’s Tsim Sha Tsui district. The facility has been in commercial operation since 1994 and generates 10 billion kilowatt-hours of electricity a year to Hong Kong and Guangdong Province, according to the website of the Hong Kong Nuclear Investment Company Ltd., a CLP unit that owns 25 percent of the plant. State-owned Guangdong Nuclear Investment Co. owns the remaining 75 percent.

CLP released its statement in response to a report on Radio Free Asia. The electricity supplier said that while the event was “below the rating” for the International Nuclear Event Scale that would require it to be reported, it had notified China’s National Nuclear Safety Administration, a central government agency, and the Daya Bay Nuclear Safety Consultative Committee, made up of Hong Kong legislators and academics.

Plant operators reported the incident to Chinese officials on May 24, CLP spokesman Justin Lui said by telephone.

“This is just like any other operating incident in the plant, the information is reported, we have been very transparent in the way we handled the information here,” said Richard Lancaster, managing director for CLP Power Hong Kong Ltd. in a phone interview on Bloomberg Television.

Operations Unaffected

Calls to lawmaker Raymond Ho Chung-tai, chairman of the Hong Kong consultative committee, weren’t immediately returned.

Operations at the power plant were unaffected, CLP said.

The Hong Kong Observatory has set up 10 radiation monitoring stations to keep track of environmental radiation levels, according to Hong Kong’s Security Bureau. The monitors haven’t shown abnormal readings since May 23, the government said in a statement.

While no problems were found in the air, the Observatory will check samples of food and water, said John Chan, Acting Senior Scientific Officer of the Hong Kong Observatory.

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

CLP said a task force of nuclear experts was formed to investigate the situation.

The 1986 nuclear disaster at Chernobyl atomic station in the Ukraine sparked protests in Hong Kong against the Daya Bay plant in the mid-1980s. Environmental activists were concerned about the risks of building a plant close to Hong Kong.

CLP Holdings fell as much as 1.2 percent in intraday trading in Hong Kong to HK$54.75, and was at HK$55.40 at the exchange’s midday break. The shares have risen 5.2 percent this year compared with an 8.2 percent decline in the benchmark Hang Seng Index.

--With assistance from Wing-gar Cheng. Editors: Dirk Beveridge, Ang Bee Lin.

To contact the reporter on this story: Debra Mao at dmao5@bloomberg.net

To contact the editor responsible for this story: Douglas Wong at dwong19@bloomberg.net