Risk assessment studies in connection with the new gas-fired power plant installations identified the presence of the LNG tanker as the main “hazardous” source, posing the biggest risks of a major accident.
But according to an assessment of the studies conducted for the main regulatory safety entities, particularly the Occupational Health and Safety Authority and the Civil Protection Department, none of the accident scenarios studied “exhibit risks of unacceptable levels” and the majority would be “within the broadly acceptable risk area” according to international standards.
The installations for the new gas-fired plant.“A limited number of floating storage unit [LNG tanker] major-accident scenarios exhibit a risk level of disastrous consequences with remote probability,” the reports say.
The process identified as the most prone to accidents refers particularly to the ship-to-ship transfer of LNG onto the tanker and the carriage of liquid gas through a pipeline to the jetty until it reaches the regasification unit on shore.
This is the process where a possible leak of gas can happen.
Still, according to various studies, an accident in this area will not have major effects on the civil populations surrounding the power station and should be contained to the areas within the boundaries of the Delimara power station compound.
However, the safety authorities are not taking any chances and have recommended a number of additional measures to be included as conditions and binding terms on the operators of the power plant as part of the operational permit before commissioning starts.
The process identified as the most prone to accidents refers particularly to the ship-to-ship transfer of LNG onto the tanker
Among other things, it is recommended that a new, detailed study, known as an FSU rollover, be carried out by Electrogas to specify incubation times, excess boil-off gas rates and tank pressure build up. This has to be submitted before the start of operations.
The regulatory authorities also want the development of a specific operational procedure to “detect, monitor and avoid LNG stratification and to prevent and avoid rollover and venting of FSU tanks in the port, prior to an LNG transfer”.
The Environment and Resources Authority is being urged to insist with the operators – Enemalta and Electrogas – to provide a final version of an external emergency plan, including procedures to be adopted by the port authorities and, in particularl to determine exclusion zones for other vessels next to the FSU in all its positions, including when it is attached to the storm mooring system in case of bad weather conditions.
According to the studies submitted by the ERA as part of the 30-day-long public consultation, the massive LNG tanker will mostly be berthed along the jetty supplying liquid gas to the new regasification terminal.
However, in case of inclement weather, which is predicted to happen at least three times a year, the tanker will be winched off further out at sea through a new safety mooring system.
The refilling operation of the tanker will occur once every six weeks through an identical massive LNG tanker.
This will not be a straightforward operation and is estimated to take five days each time, as the refilling exercise has to be done in two separate instalments.
The studies identify the ship-to-ship refilling exercise as the most dangerous of the whole operation, where further safety precautions are to kick in.
The latest version of the safety report published by the ERA was completed on Tuesday.