Abstract
According to the international standards ISO 16924, EN 13645 and NFPA 52, LNG fuelling stations need to include a means of containing spilled LNG in order to reduce the possible consequences of a spill. This can be accomplished by placing the LNG-containing installations inside a bund or by draining spills to a retention area remote from the storage area. In some standards, however, an exception to this requirement is provided. The ISO 16924 standard states, for example, that containment of LNG spills from the storage tank and associated equipment is not required if it is demonstrated that the consequences of LNG spills can be safely mitigated without the use of a containment. The EN 13645 standard specifies, on the other hand, that a containment system must only be provided if leaks of flammable liquids are considered to be a possible scenario. As a result of this ambiguity in international standards, local legislation will sometimes prescribe that the construction of a bund or equivalent containment system on LNG fuelling stations is not required, while it is mandatory in other European regions. In this paper, the effectiveness of a bund or containment system on LNG fuelling stations is assessed based on consequence and risk calculations. However, the paper will also point out some pitfalls that occur when using standard risk calculations to assess the effectiveness of safety measures such as a bund.
