Special neutron measurement results from spectral positions of the Jülich FKS steel irradiation capsules

For the German project "Forschungsvorhaben Komponentensicherheit" (FKS, i. e., Structural Integrity of Components) steel specimen irradiations have been carried out in the Jülich Merlin-type reactor (FRJ-1). The neutron monitoring to these irradiations is described in a German report (Jul-2087). In this context, some special considerations and results are given here, i. e., an experimental investigation of the fast neutron spectrum variation over a thick steel plate (in a special dosimetry test experiment); a comparison of the outcome of this investigation with the results from other FKS participants; and finally, the evaluation of the neutron exposure expressed in displacements per atom (dpa) in the centre of that steel plate