DLC-0023 ZZ-CASK/F.

ZZ-CASK/F

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FORMAT: ANISN, DOT, MORSE

NUMBER OF GROUPS: 40 group set.

NUCLIDES: H, Be, B-10, C, N, O, Na, Mg, Al, Si, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Mo, Ta, W, Pb, 235U, 238U, 239Pu, and 240Pu.

ORIGIN: ENDF/B-2 library, although some data were taken from other sources.

WEIGHTING SPECTRUM: Representative of a water-uranium mixture.

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The data were designed for use in shielding analysis of PWR depleted uranium shipping casks. Results of such an analysis are given in ref. 2. The data were collapsed from a fine group structure using a weighting function representative of a water-uranium mixture (3). Thus, the application of this data for problems not similar to the shipping cask type should be done with caution.

The library was compiled for several elements that are commonly used for shielding calculations. The coupled P3 cross sections are given in the ANISN format which permits their usage in the discrete ordinates codes ANISN and DOT as well as the 3-dimensional Monte Carlo code MORSE. The data sets from which DLC-23 are derived are listed in ref.3.

The library contains data for H, Be, 10-B, C, N, O, Na, Mg, Al, Si, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Mo, Ta, W, Pb, 235U, 238U, 239Pu, and 240Pu.

The source for the neutron cross sections was primarily the ENDF/B-2 library, although some data were taken from other sources, when necessary, as indicated in ref.3.

The SUPERTOG code was used to generate resonance corrected fine group cross sections for 104 energy groups from ENDF/B library.

Single-level Breit-Wigner or multi-level Breit-Wigner resonance parameters were used by SUPERTOG to generate point cross sections for the resonance nuclides. Approximately 100 points per resolved resonance were used to integrate the point cross sections for the fine groups. In the unresolved resonance region 81 points per fine group were used for the integration. A 1/E spectral weighting function was used.

The multigroup neutron cross sections in a 22 energy group structure were obtained from the 104 group cross sections by averaging the various elemental cross sections across a fine group flux calculated by ANISN for a uranium-water mixture using fine group cross sections. This weighting function is given in ref.3.

The secondary gamma-ray production cross sections were calculated for an 18 group gamma energy structure by the MUG code. The multigroup neutron cross sections, the secondary gamma production cross sections, and the gamma-ray transport cross sections were coupled to form a 40 group set. This is the same 40 group structure as used by Straker for various shielding calculations and it is tabulated in ref.3.

Calculations of the neutron and gamma-ray fluence from several shielding problems have been performed and some results of these calculations are discussed in ref.2.

To read the CASK data from a card image tape and rewrite it on an unformatted tape requires 23 seconds on the IBM 360/91.
ZZ-CASK/F (DLC-0023/03): The library generator test case was executed by NEA-DB on IBM 370/168 in less than 5 CPU seconds.

LIBGEN - is a modified version of the library generation routine which is available in the ANISN code package. This version will read data from a card image tape, the mode by which CASK is distributed and write an unformatted tape for direct use with ANISN.

• G.W. Morrison, E.A. Straker, and R.H. Odegaarden: 'A Coupled Neutron and Gamma-Ray Multigroup Cross Section Library for Use in Shielding Calculations' Trans. Am. Nuc. Soc., 15, 535 (1972).

• G.W. Morrison, E.A. Straker, and R.H. Odegaarden: 'The Use of the MORSE Monte Carlo Code to Solve Shielding and Criticality Problems of Spent Fuel Casks' Trans. Am. Nucl. Soc., 15, 547 (1972).

• R.W. Roussin and J.B. Wright: 'Contents, Energy Group Structure, and Weighting Function Used for DLC-23/Cask' Informal Notes (1972).

Neutron Physics and Mathematics Divisions, ORNL, USA
Science Applications, Inc. Huntsville, Alabama, USA
Div. of Material Licensing, U.S.A.E.C., Washington, D.C., USA