Page 84 - Neutrons for Sciences and Society

Neutrons for Science
Our study has revealed that the design objectives can be
met by both the H2O and the D2O cooled version. There are many features common to both versions. There are, however, characteristic differences: the H2O version has a simpler cooling circuit, offers simpler fuel handling and is less expensive; it will also be somewhat simpler to operate. The D2O version has a larger high‐flux volume available for experiments and somewhat lower backgrounds. The fuel is at a lower temperature level, making a later increase of flux and power possible, and the problem of the core shroud67 is less severe. The fuel cycle costs will be slightly lower, partly due to lower power, partly due to the longer duration of the fuel cycle. On the basis of the results of this study, the steering committee of the project will make a decision on the coolant medium within the very near future. After this, the preliminary design can be rapidly completed and it is hoped to pass some design contracts to industry in the not to distant future. Scheduled completion date for the reactor is late 1971.
There are no definitive conclusions but Dautray and Beckurts, supported by Kouts, the father of the Brookhaven reactor, favoured the heavy water option that is best for the users. This choice led to severe criticism from the CENG towards Dautray, but was afterwards supported by Horowitz.
This was not yet the final choice, and at its first meeting, the steering committee on 19 January 1967 again had a debate on the subject. The Germans insisted on the aim of realising the best possible reactor, which was with heavy water cooling. The
67 This is the barrier which separates the light water coolant at 12 bars from the reflector of heavy water at about atmospheric pressure.
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