**1. NAME AND TITLE**

ALBEMO: Albedo Monte Carlo Code System.

**2. CONTRIBUTOR**

INTERATOM, Bensberg, Federal Republic of Germany, via the OECD Nuclear Energy Data
Bank, Gif-sur-Yvette, France.

**3. CODING LANGUAGE AND COMPUTER**

FORTRAN IV; CDC 6400/6600.

**4. NATURE OF PROBLEM SOLVED**

ALBEMO calculates the transport of particles (neutrons or gamma-rays) through cavities such
as multiple bent pipe ducts or the distribution of particles within empty spaces of large volume.
Using a combination of albedo and Monte Carlo methods, it can also be used to calculate the
distribution of heat radiation.

**5. METHOD OF SOLUTION**

ALBEMO is a Monte Carlo code system using the albedo concept. It utilizes a data library
with reflection coefficients for determining the energy moderation and, for gamma-rays only, the
reflection angle depending on the angle of entry. For reflected neutrons, a cosine-shaped angular
distribution is assumed. The data library is produced by a one-dimensional Monte Carlo code.
Implementing the albedo concept, ALBEMO assumes that the reflected particles are re-emitted at
the same spot where they entered a wall. At any place of the geometry, detector planes can be
defined, where the energy and particle fluxes are computed. Provision is made for splitting as a
variance-reducing technique.

**6. RESTRICTIONS OR LIMITATIONS**

Calculations with ALBEMO are accurate, if the dimensions of the empty spaces are large in
relation to the migration lengths of the particles within adjacent walls. ALBEMO can only be used
for reflection problems. Transmitted particles cannot be considered. X-Y-Z geometry is utilized.

**7. TYPICAL RUNNING TIME**

No study has been made by RSIC of typical running times for ALBEMO.

**8. COMPUTER HARDWARE REQUIREMENTS**

ALBEMO runs on standard CDC 6400 or 6600 equipment.

**9. COMPUTER SOFTWARE REQUIREMENTS**

A FORTRAN IV compiler is required.

**10. REFERENCES**

K. Muller and H. Vossebrecker, "ALBEMO, A Program for the Calculation of the Radiation Transport in Void Volumes with Reflecting Walls," INTERATOM ITB 75.10 (ORNL-tr-4008) (February 1975).

D. Luigs, "Instruction Notes on the System Library," INTERATOM Memo Nr. D-A 395 (August 1970).

R. Vogt, "Description of the Sub-Program DRUKAS," INTERATOM Memo Nr. 33.798.2
(November 1974).

**11. CONTENTS OF CODE PACKAGE**

Included are the referenced documents and one (1.2MB) DOS diskette which contains the
source code and sample problem input and output.

**12. DATE OF ABSTRACT**

October 1978; revised March 1982, January 1983, January 1985.

**KEYWORDS: ** MONTE CARLO; NEUTRON; ALBEDO; GAMMA-RAY; COMPLEX
GEOMETRY; DUCT GEOMETRY; CAVITY