Radiography with neutrons can yield important information not obtainable by more traditional methods. In contrast to X-rays as the major tool of visual non-destructive testing, neutrons can be attenuated by light materials like water, hydrocarbons, boron, penetrate through heavy materials like steel, lead, uranium, distinguish between different isotopes of certain elements, supply high quality radiographs of highly radioactive components. These advantages have led to multiple applications of neutron radiography since 1955, both for non-nuclear and nuclear problems of quality assurance. The required neutron beams originate from radioisotopic sources, accelerator targets, or research reactors. Energy "tailoring" which strongly influences the interaction with certain materials adds to the versatility of the method. Since about 1970 norms and standards have been introduced and reviewed both in Europe (Birmingham, September 1973) and the United States (Gaithersburg, February 1975). The first world conference on neutron radiography will take place in December 1981, in San Diego, U.S.A. . In Europe the interested laboratories inside the European Community have entered into systematic collaboration through the Neutron Radiography Working Group (NRWGl. since May 1979. This Handbook has been compiled as one of the common tasks undertaken by the Group. Its principal authors are J.C. Domanus (Ris0 National Laboratory). and R.S. Matfield (Joint Research Centre, Ispra) Major contributions have been received from R. Liesenborgs (SCK/CEN Mol) R. Barbalat (CEN Saclayl.

Ouverts a I'ensemble de la communaute internationale, les symposia ASTM-EURATOM sur la dosimetrie des rayonnements de reilcteur traitent de tous les sujets de dosimetrie dans tous les systemes a neutron: dosimetrie des experiences en reacteur, codes d'ajustement, precision, etalons et intercomparaison, donnees nucleaires, techniques de mesure, correlation de dommages radio-induits, echauffement nucleaire, etc ...appliques principalement aujourd'hui aux problemes des reacteurs a eau legere, des reacteurs a neutrons rapides et aux systemes a fusion. Les travaux en dosimetrie, tout comme I'ensemble du domaine de I'energie atomique, sont moins caracterises aujourd'hui par des idees scientifiques franchement nouvelles que par la necessite d'echange, de cooperation, de collaboration, appliques a la satisfaction de besoins de type industriel ou quasi-industriel. L'organisation de nos symposia a suivi cette evolution.Nombre de ceux qui y ont participe ont un souvenir emu du ler symposium a Petten en 1975, qui fut une reussite complete.L'organisation et Ie devouement du CCR de Petten y avait beaucoup contribue. Et puis, aussi, c'etait un commencement, c'etait Ie premier de nos symposia ...Les symposia suivants, alternativement aux USA et en EUROPE, a rythme sensiblement bi-annuel, ont du faire face progressivement a un besoin plus grand d'echange et de discussion par petits groupes, ainsi qu'a afflux croissant de propositions de communications de valeur. L'organisation a du s'adapter en consequence. Ce 5eme sy~posium ASTM- EURATOM represente, de part sa belle reussite, une etape importante de cette evolution et un garant de la maturation correspondante.

Radiography with neutrons can yield important information not obtainable by more traditional methods. In contrast to X-rays as the major tool of visual non-destructive testing, neutrons can be attenuated by light materials like water, hydrocarbons, boron, penetrate through heavy materials like steel, lead, uranium, distinguish between different isotopes of certain elements, supply high quality radiographs of highly radioactive components. These advantages have led to multiple applications of neutron radiography since 1955, both for non-nuclear and nuclear problems of quality assurance. The required neutron beams originate from radioisotopic sources, accelerator targets, or research reactors. Energy "tailoring" which strongly influences the interaction with certain materials adds to the versatility of the method. Since about 1970 norms and standards have been introduced and reviewed both in Europe (Birmingham, September 1973) and the United States (Gaithersburg, February 1975). The first world conference on neutron radiography will take place in December 1981, in San Diego, U.S.A. . In Europe the interested laboratories inside the European Community have entered into systematic collaboration through the Neutron Radiography Working Group (NRWGl. since May 1979. This Handbook has been compiled as one of the common tasks undertaken by the Group. Its principal authors are J.C. Domanus (Ris0 National Laboratory). and R.S. Matfield (Joint Research Centre, Ispra) Major contributions have been received from R. Liesenborgs (SCK/CEN Mol) R. Barbalat (CEN Saclayl.

The International Topical Meeting on Irradiation Technology took place two the Neutron and its Applications (Cambridge, weeks after the Conference on th U. K.) marking the 50 anniversary of the discovery of the neutron. The application of neutrons from research reactors for materials testing requires a large variety of irradiation devices (vehicles) and their out-of-pile control and recording equipment. The in-pile sections are sophisticated in design and assem bly, expensive, and consumable. There have been only a few international con ferences on irradiation testing, the last one being limited to fast breeder reactor work (Jackson, Wyoming, September 1973). In 1982, however, two conferences picked up similar topics -the ANS Conference on Fast, Thermal, and Fusion Reactor Experiments (Salt Lake City, Utah, April 1982), -the Grenoble meeting (these proceedings). Overlapping has been avoided by putting the accent of the U.S. conference on fast reactor work, and on thermal reactor experiments at Grenoble. Put to gether, both conferences ligned up more than 130 papers in this very specialised field, demonstrating a high level of technological development as opposed to a decreasing number of large materials testing reactors available. The editors wish to acknowledge the flawless organisation of the meeting by CEN de Grenoble and the personal commitment of CEN staff to its success. Special thanks go to F. Merchie andJ.F. Veyrat of the Service des Piles. P. von der Hardt H. R6ttger XIII P. von der Hardt and H. Rottger (eds.), Irradiation Technology, xiii."

Proceedings of the Second World Conference, Paris, France, June 16-20, 1986