[en] The decommissioning of nuclear power plants and their supporting nuclear fuel cycle facilities after they have completed their useful functions can be accomplished with present-day technology, given the requirements and sufficient resources to do so. However, the magnitude of a decommissioning project is influenced by specific plant design features. Although nuclear facilities are designed and built to insure safe and economic operation, the selection of certain features could dictate the ease or difficulty encountered during decommissioning. The proceedings of this Specialist Meeting reflect the views of experts from various disciplines (civil and mechanical design, decontamination, radiological protection, waste management and operations) towards those considerations that can be taken at the design phase of a nuclear facility and which could have an important influence during decommissioning. The proceedings therefore represent a synthesis of the present thinking towards designing for decommissioning

[en] Replacement of the failed Acid Recovery Evaporator was completed in October 1979. Before dismantling of the evaporator, the equipment and pipes in acid recovery cell were decontaminated with HNO₃-NaOH, and subsequently with alkaline KMnO₄-HNO₃-EDTA. Dismantling of the evaporator was conducted for about 3 months with about 9 thousand man-days. The evaporator, cut into 7 pieces, was taken out from the cell, put in stainless steel containers and stored on the site. Our view obtained through above practice is presented for review of the designers of nuclear facilities

[en] The situation in Sweden regarding decommissioning of nuclear facilities is described as well as the different roles of the safety authorities. Complete removal of all radioactive material from a nuclear facility at decommissioning would probably be required. Of the two reactors shut down in Sweden, the research reactor R1 is now ready for final decommissioning. The Agesta nuclear power plant, shut down in 1974, may be subject for an international cooperation on decommissioning

[en] The paper presents ideas to aid the decommissioning of reactor systems having steel pressure vessels and separate concrete biological shields. The dismantlement of internal components are discussed, especially the handling of components which have no lifting attachments. The paper questions the current designs of concrete biological shields and makes suggestions for a more demountable type of structure. Difficulties in releasing nuts are discussed with a proposed nut design to aid cropping. The paper concludes with a suggestion for ensuring all new designs are submitted to a decommissioning assessment before construction commences

[en] Due to the activation of structural materials surrounding the reactor core, one should avoid unnecessary production of long-lived radionuclides. This paper shows that for the construction of future nuclear power plants, the contents of Co, N₂, Nb and Mo in the steel (reactor pressure vessel material and its internals) and of Eu, Ni, (Ho) and Co in the concrete for the biological shield, should be kept as low as possible

[en] Assessment of the requirements associated with decommissioning is made for cost and safety making comparison among those of construction, operation and decommissioning. Main principles of practice are easy access to facilities, easy separation of components, easy separation of contaminated parts from noncontaminated parts, and reduction in quantity of materials having contamination and induced activity. In practice now we are considering of a few points as follows: width of passage and angle of turning corner, free space around components, coated surface of concrete floor with impermeable paints, use of less induced materials for biological shield

[en] The paper presents some of the recommendations for the design and operation of new reprocessing plants, as concluded from the experience gained in the operation and decontamination of the Eurochemic multipurpose demonstrational reprocessing plant and the partial decommissioning of some of its facilities. After a short summary of the history of Eurochemic, some reflections are put forward on the factors that should be considered when selecting the basic process, designing and installing equipment, determining cell layouts, and planning plant operation

[en] Requirements to better decommissioning of nuclear power plants must be judged in regard to requirements to operation and safety. It turns out, that many requirements to decommissioning and operation are similar whereas some requirements to decommissioning and safety are opposite. In the past a lot of improvements in plant design until to basic changes in design concepts have been proposed to ameliorate or to facilitate decommissioning. Some of these proposals are evaluated in regard to the above mentioned requirements of operation and safety. It turns out that many of these proposals are not reasonable because they lead to deteriorations of safety or operation

[en] The final dismantlement of nuclear power stations could be made easier and less expensive by - making the suitable choice between otherwise comparable alternatives at the design stage; - introducing design changes mainly of a preparatory character for easing the processs of dismantlement. The paper discusses three examples of such choices or changes in the field of civil engineering of light water reactors

[en] This paper points out the aims to reach in order to facilitate the decommissioning of nuclear plants. Some technical steps within this goal are described. Connections between decommissioning requirements at the design stage and investments, safety and operation. The behavior of the different partners: operator, owner, safety authorities, designer and industrial architect is examined