THE Secretary for Security, Alistair Asprey, has written to legislator Christine Loh Kung-wai telling her that he will ensure that any manager to be appointed at the Daya Bay nuclear power plant is competent. He was responding to a letter from Ms Loh, vice-chairman of the Legislative Council environmental affairs panel, in which she called reports of a change of manager ''extremely disturbing''. The reports had stated that a deputy station manager at the Chinese plant, Fan Heming, was expected to be the first mainland chief despite having no nuclear experience. French operator Electricite de France (EdF) and the Hong Kong Nuclear Investment Company (HKNIC) can nominate the station manager until 1999. But incoming EdF station manager Pierre Decaix said that he expected to hand over to his mainland deputy within three years, raising fears the French might pull out sooner than expected. HKNIC chairman Ross Sayers said: ''Mr Decaix was recently appointed as station manager . . . under a two-year contract with an option to extend for a further year. I expect him to remain until the end of his contract.'' Ms Loh had asked what role the Government could play in ensuring personnel were fully qualified. Mr Asprey and Secretary for Economic Services Gordon Siu are on the HKNIC board. Mr Asprey's letter said: ''I can assure you that Gordon Siu Kwing-chue and I, through HKNIC, will ensure that, at the appropriate time, anyone who is to be considered for appointment as station manager has the necessary experience and qualifications for the job.'' He also said that he had asked HKNIC to forward to Ms Loh information on ''the types of qualifications normally required of a nuclear power station manager''. ''HKNIC takes a very active interest in safety matters . . .''