FAST NEUTRON ATTENUATION IN LARGE IRON AND SODIUM COLUMNS
In nuclear power reactor projects the knowledge of the attenuation of fast neutron fluxes at large penetration depths is of great importance. The JRC focussed its interest on iron and sodium which play a particularly important role in advanced reactor projects. Two mock-ups were prepared for this purpose: one assembly made of iron plates forming a block of 145 X 145 X 130 cm**3 and one consisting of containers filled with sodium composed to a column of 390 cm length with a cross section of 2.7 m**2. Longitudinal and transversal flux profiles were determined with threshold and resonance detectors under Cd. These measurements have been compared with detailed flux calculations obtained by the Monte Carlo code TIMOC, using the EURLIB4 library in its 100 group structure and two point detector options based on the "last collision" and the "once more collided estimator" concept. In a first analysis flux measurements in the empty channel served for the calibration of the neutron source in terms of intensity and spatial distribution. On this basis the comparison of sulphur activation measurements in sodium showed an excellent agreement with calculations even at long distances from the source. Calculations modelling the other measurements are not yet completed but first comparisons look again quite promising.
Bibliographic Reference: 9TH EUROPEAN TRIGA USERS CONFERENCE, CASACCIA, ROMA (ITALY), OCT. 7-9, 1986 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907 MENTIONING PAPER E 32909 ORA
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Record Number: 1989125057600 / Last updated on: 1987-11-01
Available languages: en