**1. NAME AND TITLE**

PRIMEDANA-2: Collapses Multigroup Cross Sections and Obtains Reaction Parameters by
Solving Transport or Diffusion Equations.

**AUXILIARY ROUTINES**

TEMPO: Produces effective cross sections for COLAPS, MED or ANALITS.

COLAPS: Collapses multigroup cross sections.

MEDS: Multigroup one-dimensional code for neutron physics computation of multizone fast breeders.

ANALITS: Source iteration method of solving multigroup diffusion equation.

**DATA LIBRARIES**

BNAB-78: 26 neutron group cross section library.

BNAB-64: 26 neutron group cross section library.

**2. CONTRIBUTOR**

Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia,
Bulgaria.

**3. CODING LANGUAGE AND COMPUTER**

Fortran IV; EC 1040 and IBM 3081.

**4. NATURE OF PROBLEM SOLVED**

PRIMEDANA-2 is a modular code system for neutron physics calculations of fast reactors.

**5. METHOD OF SOLUTION**

PRIMEDANA-2 prepares effective multigroup microscopic and macroscopic cross sections for
compositions characteristic of fast neutron reactors. The shielding factor approach is used. Optionally
the multigroup cross section library can be collapsed to a few-group cross section library. The
multigroup diffusion equation is solved using the method of the central finite differences and/or a new
semi-analytical method.

**6. RESTRICTIONS OR LIMITATIONS**

None noted.

**7. TYPICAL RUNNING TIME**

Sample cases execute in less than one minute on the IBM.

**8. COMPUTER HARDWARE REQUIREMENTS**

PRIMEDANA-2 was developed on the EC 1040 and runs on the IBM 360/370 and IBM 3081
computers.

**9. COMPUTER SOFTWARE REQUIREMENTS**

A Fortran IV compiler is required.

**10. REFERENCE**

J. D. Jordanov and P. P. Groudev, "User's Guide for PRIMEDANA-2 System," Institute for
Nuclear Research and Nuclear Energy, Bulgaria (1988).

**11. CONTENTS OF CODE PACKAGE**

Included are the referenced document and one (1.2MB) DOS diskette which contains the source
code, sample problem input and output, and cross section libraries.

**12. DATE OF ABSTRACT**

July 1986; revised October 1987, April 1989 and November 1989.

**KEYWORDS: ** NEUTRON; CROSS SECTION PROCESSING