Hong Kong authorities have stressed that an operational glitch at a nuclear plant in neighbouring Shenzhen involving the closure of a cooling water isolation valve earlier this week posed no risk to public health or the environment. The Security Bureau said on Sunday that Guangdong’s Nuclear Emergency Committee Office had notified it of an operational event at Ling Ao Nuclear Power Station in mainland China, that occurred last Thursday. The plant, about 50km (31 miles) north of urban Hong Kong,.