Joint Research Collaboration Statement
The UK’s Science and Technology Facilities Council (STFC) Hartree Centre, IBM, the multinational information technology company, and Gexcon, a world-leading company in the field of safety and risk management, have agreed to collaboratively work towards the development of improved methodologies in the areas of probabilistic explosion risk assessment and equivalent flammable cloud methods.
Under the UK-Government funded IROR (Innovation Return on Research) programme, the STFC Hartree Centre and IBM Research are collaboratively engaged in developing digital assets in several industrial relevant areas. Along with Gexcon’s depth of experience in advanced dispersion, explosion, and fire modelling, they will bring the best of each organization’s R&D capabilities together to improve and standardize the methods used in the industry.
Studies conducted by regulators and other industry bodies have highlighted a potential lack of consistency in explosion modelling results and reliance upon expert judgment in the Explosion Risk Assessment (ERA) process, both of which present cause for concern. These are primarily due to the uncertainties that are inherent with the techniques used, especially where statistical data (such as wind probability, leak frequency, and ignition probability) with its own associated uncertainties are used to provide input. Additional sources of uncertainty arise both from the modelling techniques used to determine the consequences from a release and the subsequent ignition leading to an explosion, along with the engineering judgment that is required in order to select the most appropriate scenarios that will be considered.
Furthermore, equivalent flammable cloud methods to represent the volume of flammable gas are used as a pragmatic means of reducing the computational cost associated with generating overpressure exceedance curves through an explosion modelling Quantitative Risk Assessment (QRA) using Computational Fluid Dynamics (CFD). FLACS supports the ‘frozen cloud concept’ by being able to produce output (e.g. Q8, Q9) for several mix values (based on leak and ventilation rates ratios) in a single simulation. Published studies investigating these methods have drawn quite different conclusions, with the Q9 approach leading either to significant under-prediction of overpressures or giving overpressures that were in broad agreement with the experimental data.
This joint research project aims to explore approaches to assess the impact of uncertainty in the model inputs on probabilities of occurrence of dangerous phenomena. The main aim is to develop a computationally efficient numerical method that can deliver accurate approximations of statistical quantities of interest even in high-dimensional scenarios, i.e. in problems with multiple sources of uncertainty.
To address the issues raised above, and considering the implications of the outcomes of this joint project, Gexcon, STFC, and IBM Research intend to engage proactively with all relevant stakeholders (including the HSE, HSL and relevant industry bodies such as OGUK) in order to investigate and promote new methodologies with an aim to improve and develop good practice guidelines. These would provide more consistent modelling guidance and input parameters within the ERA to help provide greater transparency in the process and to harmonize results across the industry.