Verification of the MC2-3 Gamma Library

Abstract

The new gamma library was generated based on the 94-group gamma structure, including delayed gamma and beta data, using the PreGAMMA and GenGAMMA codes with ENDF/B-VII.0 data. The new gamma library was first verified using the 2D benchmark problems that were introduced in the GAMSOR manual, showing that the neutron and gamma heatings from DIF3D were in good agreement with MCNP solutions within 5% even in the non-fuel regions of both cores with uranium or plutonium dominant fuel compositions. Similarly, the DIF3D power solutions for additional simpler 1D problems with 3 or 6 regions showed good agreement with MCNP solutions. Note that all DIF3D calculations were based on the 230group neutron and 94-group gamma data.For the EBR-II benchmark problem, the DIF3D solution with the new gamma library maintained good agreement in the power distribution with the MCNP solution, which is comparable to the DIF3D results with the current 21-group gamma library. The use of delayed gamma and beta data increased powers at the dummy assemblies by 26%, which appears to be reasonable. Further detailed verification tests may be necessary and, more importantly, validation tests are required against measurement data.

Verification and Validation Tests of the Gamma Library of the ARC Software Package (Rev.1)

“…First, to verify the gamma library data, 0D homogeneous problem was solved for every isotope in the MC 2 -3 gamma library. The 1D and 2D benchmark problems of the previous study [5] were analyzed again using the revised gamma library. In this report, only the 1D benchmark results are presented, since the 2D benchmark results is qualitatively the same as the 1D benchmark results.…”

“…In order to verify the data itself by excluding the transport calculation errors, an infinite homogeneous problem was solved for every isotope in the MC 2 -3 gamma library. The 1D benchmark problems developed in the previous study [5] were analyzed again to examine the performances of the revised gamma library and MC 2 -3 against the original version. As the final verification problem, the EBR-II SHRT Run 138B benchmark problem [6] was solved.…”

“…The four 1D benchmark problems developed in the previous study [5] were analyzed again to examine the performances of the revised gamma library and MC 2 -3 against the original version. The problems 1 and 2 were constructed based on a sodium cooled fast reactor with zirconium alloy fuel.…”

“…To verify the gamma library of MC 2 -3 and its generation procedure, a preliminary verification study was performed [5]. In this study, the EBR-II Shutdown Heat Removal Test (SHRT) benchmark problem [6] as well as simple zero-, one-, and two-dimensional (0D, 1D, and 2D) benchmark problems were analyzed.…”

“…This verification test against the MCNP results was performed for all the isotopes in the MC 2 -3 gamma library except for six minor isotopes, of which data are not available in the MCNP library or MC 2 -3 neutron library. The 1D and 2D benchmark problems devised in the previous report [5] were analyzed again to test the improvements due to the corrections of the utility programs and data processing errors.…”