Paris, 6 February 1997
Some sixty specialists met under the aegis of the OECD Nuclear Energy Agency (OECD/NEA) in Cordoba, Spain, from 20 to 23 January 1997 to discuss progress in the regulation of long-lived radioactive waste.
Hosted by the Spanish Nuclear Safety Council (CSN) and the Spanish Radioactive Waste Agency (ENRESA), this international workshop made possible an in-depth exchange between those in charge of developing and implementing radioactive waste disposal systems, and those responsible for regulating these systems to ensure adequate safety.
In many OECD countries substantial resources are being devoted to developing radioactive waste disposal systems and the scientific and practical knowledge necessary to licence them. This is a particularly challenging task for long-lived radioactive wastes, such as spent nuclear fuel or high-level waste from the reprocessing of spent fuel, which need to be isolated from the biosphere for very long periods of time.
Establishing a sound licensing process and resolving the associated regulatory issues requires a multi-disciplinary approach in connection with which radiation and environmental protection, nuclear safety and waste management specialists play key roles. A mutual understanding and clear rules must also be established between those proposing and developing a disposal concept and those who must independently assess its acceptability from a safety standpoint.
The workshop contributed to a deeper understanding of the regulatory approaches followed in NEA member countries and of the differences which exist in national regulatory systems. In particular, it was noted that while safety criteria are often expressed using different units (dose or risk) in different countries, substantive differences do not exist from a long-term safety standpoint. In this respect, it was recognised that the main objective is to ensure that future generations are protected at least to the same level of safety as is acceptable today. Translating this objective into regulatory terms depends largely on national cultures and administrative situations. Similarly, the level of proof to be provided concerning very long-term safety of geologic disposal systems is a matter of judgement in view of the existence of unavoidable uncertainties concerning the future. The participation of the public in the decision-making process is also an important element of national policies, and has a strong influence on the way the regulatory process will be conducted.
Among the suggestions made by the participants regarding further work were the drafting of rigorous but practicable regulations; the treatment of various uncertainties such as the living habits of populations in the far future and the need to make reasonable assumptions concerning these habits; and the difficulty of dealing with long-term risk issues in the context of legal and public perception considerations. The discussions highlighted that, beyond the solid scientific basis required for safety assessment, the decision-making process must ultimately rely upon expert judgement and reasonable assurance considerations, through an open and transparent process allowing for public participation. The follow-up to the workshop will be discussed further during the first half of 1997 by the three sponsoring Committees of the NEA, namely the Committee on Nuclear Regulatory Activities (CNRA), the Committee on Radiation Protection and Public Health (CRPPH) and the Radioactive Waste Management Committee (RWMC).
In conclusion, the workshop met its objectives of promoting deeper understanding of the issues, comparing the requirements that regulators may set with the scope and depth of analyses which are currently feasible, and identifying issues and problems which require additional effort.