Flux-difference methods, homogeneous systems

Cross-section sets for Assembly 6A were generated in the manner described in Ref. 3 using ENDF/B Version 1 i.e., MC homogeneous cross sections, corrected tor resonance spatial self-shielding in U and D, and wei ited with the unit-cell fluxes. The keff of the unitcell calculated with 1-D, Sn (n > 16) and the anisotropic option (Pt only) was 1% greater than that calculated In the same manner with the transport approximation. This difference disappeared, however, when the transverse dimension was made Infinite this indicated that the decrease in leakage associated with the use of S total Instead of S transport was responsible for this difference. Similar difference in keff between the two methods was found for the as-built system. 

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