Determination of Pressure Vessel Neutron Fluence Spectra for a Low Leakage Rovno-3 Reactor Core Using Three Dimensional Monte Carlo Neutron Transport Calculations and Ex-vessel Neutron Activation Data


Determination of Pressure Vessel Neutron Fluence Spectra for a Low Leakage Rovno-3 Reactor Core Using Three Dimensional Monte Carlo Neutron Transport Calculations and Ex-vessel Neutron Activation Data

Barz, H.-U.; Böhmer, B.; Konheiser, J.; Stephan, I.; Borodkin, G.

Three dimensional Monte Carlo calculations considering all known geometrical and composition details were used for the determination not only of fluence integrals but also of fluence spectra with good statistical accuracy. This was possible by the application of own specially developed codes (TRAMO) and successfully modifying variance reduction on the basis of the weight window method (TRAWEI). Modern multigroup data sets were applied. For the real representation of fission sources the burn up and power history also for the fuel rods within the fuel assemblies was considered.
The investigation was accomplished for the irradiation period seven with a special low leakage loading of the reactor. During this period Russian and German detectors were irradiated in the ex-vessel cavity and analysed by advanced gamma spectrometric methods.
The reaction rates obtained with the calculated fluence spectra were compared with activation reaction rates measured in the ex-vessel cavity. Furthermore the calculated spectra were adjusted to the experimental reaction rates taking into account the variances and correlations of calculated input spectra, detector sensitivities and measurements. Using the adjustment code COSA2 based on the maximum likelihood method best estimate fluence spectra and fluence integrals could be provided.

  • Lecture (Conference)
    9th International Symposium on Reactor Dosimetry, Sept. 2-6, 1996, Prague
  • Contribution to proceedings
    in H.A. Abderrahim, P. D'hondt and B. Osmera (Ed.), Proceedings of the 9th International Symposium on Reactor Dosimetry, Prag (pp.58-66)

Permalink: https://www.hzdr.de/publications/Publ-760
Publ.-Id: 760