Measurement of energy and directional distribution of neutron fluence inside a nuclear power plant

A detailed analysis of the neutron radiation field was performed at selected positions inside the Krümmel boiling water reactor. The measurements were performed with the PTB Bonner sphere spectrometer and with a newly developed directional neutron spectrometer based on silicon detectors mounted onto the surface of a 30 cm diameter polyethylene sphere. Both, angle-integrated and angle-differential spectral neutron fluences were determined in this way.