[en] The present position in fusion research is reviewed and discussed with relation to the requirements of an economic reactor. Meeting these requirements calls for a mission-oriented project of interdisciplinary character whose timely evolution from one with a research orientation, is a challenging management problem. The cost-effectiveness of future expenditure on fusion research is dependent upon acknowledging this challenge and realistically facing the difficult tasks which it presents. (U.K.)

No abstract available

[en] It is often said that the achievement of fusion power is a more difficult task than fission. In fission, fuel may be regarded as static. In contrast, fusion process is dynamic, and can only be started by the energy from some external source. The major difference between fusion and fission is that fusion yields about 20 MeV/neutron as compared with about 100 MeV/neutron in fission. The relative energy of several tens of keV and temperature higher than 100 M deg C are required. The basic concept of magnetic confinement is simple: the kinetic pressure of plasma, proportional to the product of density and temperature, is balanced by the pressure of a magnetic field, proportional to the square of the magnetic field intensity. Three approaches were considered to deal with this problem of poor longitudinal containment: a) fast linear pinch, b) close field lines (Tokamak, Reversed Field Pinch, Stellarator) and c) increase the magnetic field at each end of a solenoid (magnetic mirror). Most of the world fusion efforts have been devoted to study the systems with closed magnetic fields. The scale of experiments has influenced the progress of fusion researches. Advances in magnetic mirror research led to two new concepts; the first is the tandem mirror providing a long solenoid section. The second approach is the field reversed mirror. It is well to consider the benefits obtained from fusion power: fuel resources (primary fuel is Li), reaction products (²H and Li are not radioactive), nuclear runaway, active waste, and nuclear safeguards have advantage over nuclear fission. (Yamashita, S.)

[en] It is pointed out that plasma parameters for a fusion reactor have been fairly accurately defined for many years, and the real plasma physics objective must be to find the means of achieving and maintaining these specifiable parameters. There is good understanding of the generic technological problems: breading blankets and shields, radiation damage, heat transfer and methods of magnet design. The required plasma parameters for fusion self-heated reactors are established at ntausub(E) approximately 2.10¹⁴ cm^-3sec, plasma radius 1.5 to 3 m, wall loading 5 to 10 MW cm^-2, temperature 15 keV. Within this model plasma control by quasi-steady burn as a key problem is studied. It is emphasized that the future programme must interact more closely with engineering studies and should concentrate upon research which is relevant to reactor plasmas. (V.P.)

[en] The Fusion Programme in the Euratom--UKAEA Fusion Association is mainly one of plasma confinement studies in four major experimental areas. Conceptual studies of fusion reactors have been based upon the tokamak and the reversed field pinch. Particular attention has been given to the potential operating problems of toroidal fusion reactors in order to establish design principles which take note of the high availability essential in a power plant. Future plans for fusion power programmes are discussed and it is suggested that they are not obviously the quickest or most cost effective ways to establishing the credibility of fusion. It is proposed that a more aggressive programme which involved taking calculated risks could be quicker and cheaper. An additional, important advantage would be to attract into the fusion programme good engineers who feel the need to be motivated by action on a time scale less than the 30 to 50 years of much present planning

[en] An account is given of the beginning of fusion research at Harwell following early experiments at the Clarendon Laboratory and Imperial College, and which from 1948 became the Official Programme under the Atomic Energy Technical Committee. A significant event was the publication of the Lawson criteria in 1955. The design and construction of the ZETA device and the early experimental results are discussed. A new site at Culham was selected for all fusion work, and a new experiment to be known as the Intermediate Current Stability Experiment (ICSE) was proposed. Owing to budgetary constraints ICSE was cancelled in 1960. (U.K.)

No abstract available

[en] This article outlines some of the more general criteria to be used in assessing reactor potential. The interdependence of plasma and engineering parameters is considered. This demonstrated how it is the first wall power loading which is the critical parameter in assessing economic prospects. Taking some of the current conceptual designs of fusion reactors and raising the wall loading to the value needed to approach a competitive cost leads to a very challenging set of parameters. Although developed in terms of a tokamak they are figures which are applicable more generally to fusion reactors which are toroidal in form. It is not at all obvious that the tokamak could ever satisfy this criterion of economic viability, so we should not be using the parameters of existing tokamak reactor designs as the basis for assessing alternative approaches. We need to see whether there is an alternative sufficiently different as to offer a better chance of reaching these more onerous parameters. Unfortunately, so many of the alternatives differ only in magnetic geometry and their physical geometry leads to the same problems as faced by the tokamak. The traditional approach -- devising intriguing ''boxes'' for studying the confinement of plasma and then speculating on their reactor potential -- should give way to new initiatives. What we need in the fusion program is more ''reactor relevance pull'' and less ''plasma physics push'' when planning future activities

No abstract available

[en] The Study Group concentrated its work on the D-T reactor, the most likely first generation system and arguably the 'worst case' model. The only specifically nuclear hazard to persons outside a fusion power station, arises from the release of tritium to the environment. Excluding accidents, and subject to certain assumptions on reactor design, such releases will mainly affect populations near the power station and should be controllable within authorised levels. Other hazards exist which will affect the operating staff but not the general public. These arise from neutron activiation of the structure and tritium absorption in materials and contamination of waste. These hazards will be controlled by high standards of design and operation. It appears that the probability of a serious accidental release of tritium and the area of country affected depend strongly upon the hazard of a lithium fire. The full extent of the hazard and the cost of reducing the probability of the accident to an acceptable level cannot be estimated yet due to the lack of reactor designs. The Study Group has established in outline the major determinants of fusion reactor safety. To establish whether and how the requirements can be met is not possible without more information. Advanced techniques relevant to the principal problems of fusion safety - gas containment and fires in liquid metal systems - have already been developed in the development of fission reactors. Continuing re-appraisals of fusion reactor safety must be an integral part of fusion design. The recommendations of the Study Group emphasise this, and the necessity for basic physical data to aid both design and safety assessments. (author)