26 May 2012, PDF |
48 pages |
Ale BJM , Golbach GAM , Goos D , Ham K , Janssen LAM , Shield SR
RIVM Report 610066015
A so-called benchmark exercise was initiated in which the results of five sets of tools available in the Netherlands would be compared. In the benchmark exercise a quantified risk analysis was performed on a -hypothetical- non-existing hazardous establishment located on a randomly chosen location in the Netherlands. The plant was chosen as to cover many of the scenario's that will be part of a real analysis such as the release of flammable and toxic clouds; liquids, gases and liquefied gases; vessels and pipes etc. Using each participating method a complete risk analysis was performed. The participants were asked to perform a risk analysis according to the guidelines given in the coloured books. All participants however had deviations, sometimes due to the available software sometimes due to arguments of practicality, sometimes due to matters of principle. It should be noted that in practice, these differences between consultants using different (software) tools will also occur, as the application of the methods as described in the coloured books is not prescribed by law. It is not to be expected that the competent authorities will be able to detect these deviations nor that they would consistently insist that the coloured books are followed religiously. Not many differences were found in the consequences and frequencies used for those events that are listed in the coloured books. The less the methodology for the calculation of the effects of certain scenario's is established the larger the differences that were found between the results of the participants as could be expected. The results for all participants were found largely within one order of magnitude. Since the earlier benchmark exercises the situation with respect to the spread in the results has improved tremendously and more improvements are difficult if at all obtainable unless the application of the prescriptions of the coloured books is made a legal requirement.