Royal Dutch Shell has controlled a leak at its Pulau Bukom refining and petrochemical complex in Singapore, and operations have not been affected, according to company sources. The small leak occurred last week as further details were not revealed further. The Bukom site, Shell's largest wholly-owned plant, has a 500,000 bpd refinery and a steam cracker that produces more than 900,000 tpa of ethylene. Shell also reported a leak at one of the units at the Bukom site in January this year. It is not clear if the incidents are related.