The development of life-cycle and risk assessment methodology using data from AWE Aldermaston
The research described in this thesis further develops Life-Cycle Assessment (LCA) methodology to include radiological releases to air, water and as waste. A new methodology has been developed to characterise radioactive aspects based on known effects to man and behaviour in the environment. Equivalency factors have been developed for nine radioisotopes (24'Am, 137Cs56 0Co, 239Pu52 41Pu53 HI 234U, 235U and 238U). A new LCA valuation method is developed for weighting environmental impacts in an Environmental Management System (EMS). A detailed LCA inventory of environmental burdens has been compiled from data from AWE Aldermaston and used as a case study to develop and demonstrate the methodologies developed in this work. As part of the research, the links between environmental aspects and impacts has been investigated using LCA, based on the high hazard facilities at AWE Aldermaston, which is a major industrial site. The case study also includes the contribution from vehicle use in the impact assessment. The results of this work have clearly identified which facilities and hence which processes are causing the most damaging environmental impact. New risk assessment methods are developed to quantify environmental accidents, that include revised consequence definitions that can be applied without the need for modelling and thus offer an economical alternative to existing methods. A new six-step screening methodology is presented to identify potential major accidents to the environment (MATTE) and to comply with the COMAH Regulations 1999. A method to prioritise MATTE scenarios has also been developed. The research has revealed that the current approach to significance assessment does not provide enough sophistication for sites as complex as AWE Aldermaston. The impacts of most concern are environmental irradiation, the generation of all categories of waste and global warming. The impacts associated with radioactive discharges (to air, water and as waste) are given the highest weighting largely reflecting the concern of the major stakeholder groups (local community, regulatory bodies and pressure groups). The methods proposed can be readily applied to any nuclear or chemical site.