Monte Carlo Analysis of HTTR with the MVP Statistical Geometry Model
The Japan Atomic Energy Research Institute high-temperature engineering test reactor (HTTR) is a block-type gas-cooled reactor, whose 290-cm-high, 230-cm-effective-diameter active core consists of 30 fuel columns and 7 control rod guide columns. Each fuel column is a hexagonal prism and consists of 5 fuel blocks and 4 graphite reflector blocks. Each fuel block includes 31 or 33 fuel rods. A fuel rod consists of a graphite sleeve containing 14 fuel compacts, each of which includes {approx}13 000 coated fuel particles (CFPs). The heterogeneity effect of CFPs and fuel rods, which strongly depends on U-enrichment, rod pitch, etc., should be taken into account for an accurate analysis. In order to evaluate the heterogeneity effect on the nuclear characteristics of the HTTR accurately, we used the MVP continuous energy Monte Carlo code. A great number of randomly distributed CFPs were treated by the statistical geometry model (STGM) without spoiling the advantage of the continuous energy method. In summary, the heterogeneity effect of CFPs and fuel rods is evaluated to be {approx}1%{Delta}k/kk' in the cold HTTR core by using the STGM of the MVP code with both the theoretical nearest-neighbor distribution and that from the high-cost MCRDF calculation. It is also found from the cell burnup calculations that the difference of k{sub {infinity}} caused by the heterogeneity is almost constant up to the maximum burnup of HTTR.
- Research Organization:
- Japan Atomic Energy Research Institute, Nakagun, Ibaraki-ken (JP)
- Sponsoring Organization:
- none (US)
- OSTI ID:
- 786833
- Report Number(s):
- none; ISSN 0003-018X; CODEN TANSAO; ISSN 0003-018X; CODEN TANSAO
- Country of Publication:
- United States
- Language:
- English
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