**1. NAME AND TITLE OF DATA LIBRARY**

SAIL: 23 Neutron, 17 Gamma-Ray Group ALBEDO DATA for Concrete and Steel,
Based on DOT 1-1/2-D Calculations using DLC-31/FEWG1 Data.

**2. NAME AND TITLE OF DATA RETRIEVAL PROGRAMS**

No retrieval program is in the package.

**3. CONTRIBUTOR**

Science Applications, Inc., La Jolla, California.

**4. HISTORICAL BACKGROUND AND INFORMATION**

Albedo techniques for solving radiation transport problems have been applied in varying degrees of sophistication since the 1950s. The procedures used ranged from simple single scattering approximations in which only simple geometries were treated to the application of detailed three-dimensional Monte Carlo procedures which required large computers and extensive data bases of albedo and cross section information. Development of these techniques and extension of the procedures to other problems came to a near standstill in the early 1970s.

Interest in albedo data and the solution of radiation transport problems using the albedo concept
has renewed recently. This interest is centered around the need to accurately predict the streaming
of radiation, particularly fast neutrons, in the cavity region of light water reactors (LWRs) and the
transport of this radiation to the operating floor of these plants.

**5. APPLICATION OF THE DATA**

Analysis of the radiation streaming problem by using any of the several multi-dimensional Monte
Carlo procedures which have been developed is possible. However, the walls of the cavity, the
pressure vessel, and other structures and equipment in the containment are quite thick relative to the
mean free path of the radiation involved. Therefore, the Monte Carlo procedure must not only solve
the streaming problem in the cavity but must also determine the effective reflection properties of the
structural materials. The motive for using albedo technique for performing the multi-dimensional
Monte Carlo analyses is the potential for decreasing the amount of computer time required to analyze
the problem where the primary path for the radiation reaching the dose point is by a series of
"reflections" from wall materials and subsequent transport through air or void regions. The choice of
the albedo concept for treating the "reflection" of the radiation from the walls allows the analyst to
avoid the consideration of the treatment of the actual transport in the wall material.

**6. SOURCE AND SCOPE OF DATA**

The data base was developed and refined by Science Applications, Inc. (SAI). The data was contributed by SAI to the Electric Power Research Institute (EPRI) as part of a participation in the LWR Pressure Vessel Dosimetry research program. It also contains a data library, a small data conversion code, and a code for collapsing the data base into a smaller data set. The data contained in the library are able to be interfaced with computerized procedures as well as hand calculational techniques.

SAIL contains data for two types of materials, Ordinary Concrete (Type 04) and Low Carbon Steel
(A533B). These can be considered the two key materials for application to streaming problems. The
data in the library provide information for neutrons and gamma-rays incident on these materials at
various angles. The albedo data then provide the exiting distributions for neutrons and gamma-rays
as well as secondary gamma rays produced by neutron interactions in these materials.

**7. DISCUSSION OF THE DATA RETRIEVAL PROGRAM**

Not applicable.

**8. DATA FORMAT AND COMPUTER**

Fortran IV; IBM 370.

**9. TYPICAL RUNNING TIME**

This information not available.

**10. REFERENCE**

G. L. Simmons, T. E. Albert, M. L. Gritzner, and H. Till, "The SAI/EPRI Albedo Information
Library," SAI-013-79-525-LJ (January 1979).

**11. CONTENTS OF LIBRARY**

Included are the referenced document and one (1.2MB) DOS diskette which contains the source
codes written in Fortran IV, concrete and steel Albedo and CRUNCH card data, and TAPER and
CRUNCH output.

**12. DATE OF ABSTRACT**

March 1985.

**KEYWORDS: ** ALBEDO DATA