----- One of the arguments most frequently raised by objectors to nuclear power production is the spectrum of the hazard from the nuc.lear waste. In the public's perception one of the most dangerous features of this waste is the threat to future generations due to the long life of the radio-emitting nuclides. People's concern for this hazard seems to be greater than that for other types of toxic wastes, widely produced and released to the environment (heavy metals, PCBs, arsenic etc.) though these might last even longer. In fact public attitude toward risk depends very strongly on the nature of the risk, as clearly illustrated ill the initial papers of these proceedings. On this basis it appears that tile safety of the nuclear practice, including waste disposal, cannot be assessed only by comparison with other practices or risks. For this reason the analysts have accepted the challenge of investigating the long term safety of this type of waste, taking it much further than for many other known pollution problems affecting mankind. Moreover, for one of the first times lhis is being dulle IJi2fure disp,)sal. The c,)ntributiolls tu these pruceedillljs attempt to describe the specific nature of this type of assessment, pi esent ing Ilew developments which have been made in the field. These include the recourse to system variability analysis, the use of natural and archaeulugical analogues and predictive geology.

Section 1 - Risk perception and risk policy.- Understanding public risk perception.- Decision making based on risk analysis: coping with uncertainty and incomplete data.- Section 2 - From reactor safety to disposal safety.- Probabilistic risk assessment in the nuclear sector: From reactor safety to disposal safety.- Section 3 - The analyst's answer: methodologies and methods.- An introduction to systems variability analysis.- Techniques for uncertainty and sensitivity analyses.- Applications of system variability analysis codes.- The role of the code intercomparison exercises: activities of the PSAC group.- Risk calculation in long term prediction.- Section 4 - The word to the geologists: what if...?.- The use of predictive geology in the analysis of repository evolution. Description of the relevant natural phenomena.- Impact of glaciation on geological disposal: The problem of prediction and the challenge of modelling.- Section 5 - Some worked examples.- The time dimension in risk analysis.- Evaluation of the risk associated with disposal of radioactive wastes: the deterministic approach.- The sub-seabed disposal safety assessment: a worked example.- Performance Assessment of Geological Isolation Systems (PAGIS).- Section 6 - A smart approach: using natural and archaeological analogues.- Applying natural analogues in predictive performance assessment - Part 1.- Applying natural analogues in predictive performance assessment - Part 2.