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

ABBN-90: Multigroup Constant Set for Calculation of Neutron and Photon Radiation Fields and Functionals, Including the CONSYST2 Program.

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

CONSYST2: ABBN-90 retrieval code for preparation of group constants for other applications.

**3. CONTRIBUTORS**

Institute of Physics and Power Engineering, Obninsk, Russia.

ABBN, Ltd., Obninsk, Russia.

**4. HISTORICAL BACKGROUND AND INFORMATION**

ABBN-64 was the first version of the ABBN group constant set. Resonance self-shielding effects were taken into account for many nuclei and in a wide energy region. ABBN-64 was used mainly for reactor calculations.

The next ABBN version included subgroup representations of resonance structures. The anysotropy of classic scattering was taken into account in the P5-approximation. This set was based on the updated data for fuel materials. It included data of photon production and photon transport constants. The set was retrieved by the ARAMACO-2F code and was used for fast reactor and shielding calculations.

ABBN-78 was the third ABBN group constant set. It was based on the microscopic neutron data published in 1977. ABBN-78 was adjusted to the set of evaluated experiments on fast critical assemblies and contains the group constant covariance matrices. ABBN-78 was operated by the ARAMACO-S1 code.

ABBN-90 is the newer ABBN group constants version. It is based on the FOND-2 library (File of Evaluated Neutron Data) and includes data from BROND-2, ENDF/B-VI, JENDL-3 libraries, and some other sources. Calculational results by using ABBN-90 were proven in a wide set of fast and thermal critical experiments and in some shielding benchmarks.

**5. APPLICATION OF THE DATA**

ABBN-90 is recommended for neutronics calculations of nuclear reactors of all spectral types, for radiation shielding calculations, calculation of blankets of thermonuclear devices and targets of electronuclear installations, nuclear reactor material activity calculations and designing radionuclide production devices, neutron and photon radiation field calculations, medical applications, etc.

**6. SOURCE AND SCOPE OF DATA**

ABBN-90 includes group constants for nearly all chemical elements, all long-lived actinides, all important fission product nuclides and for many isotopes which may be used in a separated form (as N-15) or as burning absorber (as Gd-157). Basic data were selected from BROND-2, ENDF/B-VI and JENDL-3 evaluated nuclear data libraries by physical considerations (comparing with experiments, studying the fullness of reactions, etc.) and taking into consideration the date of evaluation. The majority of the data files were modified and data were converted to the group constant format by the GRUCON4 and PSR-171/NJOY91 codes.

The ABBN-90 set presents group constants for 28 neutron energy groups (from the thermal to 15 MeV) and for 15 photon groups. For some important reactor materials the 299 group constant set is also available. The 299 and the 28 data are processed by the CONSYST2 code simultaneously. Resonance self-shielding effects are taken into account by using Bondarenko self-shielding factors. Nikolaev's subgroup (optimized multiband) parameters are also included in the constant set and may be used in cases when the spatial dependence of group constants is essential. The ABBN-90 group constants are presented in formatted tables and can be easily read by man and computer.

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

Success in using the ABBN-90 group constants with CONSYST2 essentially depends on the right adaptation of this system to the special user problem. It maybe necessary to consult with the authors for special adaptations of the data. Lahey F77L/EM32 V5.1 was used to create the executables included in the package. The CONSYST code of the CONSYST2 Data Code System communicates the ABBN-90 group constants with such transport cods as ANISN and DOT. This retrieval code permits also using of the ABBN-90 data in Monte-Carlo calculations. The CONSYST2 Data Code System was specially designed for converting the ABBN-90 data to various applicational fields.

**8. DATA FORMAT AND COMPUTER**

As formatted file of 128 elements plus 8 special files. IBM PC's and compatibles, ASCII; CONVEX, and CYBER computers.

**9. TYPICAL RUNNING TIME**

CONSYST2 processed 25 physical regions, 20 nuclides, and 28 groups into P5-anisotropy ANISN format in 50 seconds on a PC 386/387.

**10. REFERENCES**

**a. Documentation included in package:**

G. N. Manturov, "CONSYST2 Abstract" (April 1995).

M. N. Nikolaev, A. M. Tsibulia, G. N. Manturov, "New Russian Group Constants System ABBN-90 and CONSYST2 Data Code Retrieval System" (1990).

G. N. Manturov, M. N. Nikolaev, A. M. Tsibulia, "Description of Applying the New Russian Group Constant System the ABBN-93/MULTIC and the CONSYST2 Data Code System in Monte-Karlo Calculations with the TRAMO FZR Code (FORAN Fortran Code): USER GUIDE" (December 1993).

**b. Background Information:**

V. V. Sinitsa, "Code for Group Constants Calculations with Evaluated Nuclear Data Libraries," Voprosy Atomnoy Nauki I Techniki, Issue Jadernye Constanty 5(59), M., p. 34 (1984) (Russian).

L. P. Abagyan, N. O. Bazazyants, I. I. Bondarenko, M. N. Nikolaev, "Group Constants for Nuclear Reactor Calculations," Consultants Bureau, N.Y., U.S.A. (1964).

M. N. Nikolaev, V. M. Khokhlov, "System of Subgroup Constants," Bulleten Informationnogo Centra po Jadernym Dannym: Issue 4, M., p. 420 (1967) (Rus., CNIIAI).

N. O. Bazazyants, A. S. Zabrodskaya, M. N. Nikolaev, "Group Parameters of the Neutron Scattering Anistropy," Jadernye Constanty, Issue 8, Part 2, M., p. 3 (1972) (Rus., CNIIAI).

N. O. Bazazyants, et al., "ARAMACO-2F: Code System for Providing of Radiation Transport Calculation in Reactor and Shielding by Group Constants," M. (1976) (Rus., IPM AN USSR).

L. P. Abagyan, N. O. Bazazyants, M. N. Nikolaev, A. M. Tsibulia, "Group Constants for Reactor and Shielding Calculations," (Rus. Gruppovye Konstanty dlya Rascheta Reactorov I Zaschity), M., Energoizdat (1981).

**11. CONTENTS OF LIBRARY**

The referenced documents in 10.a, the ABBN-90 data library, FORTRAN source for the retrieval programs, executables, and sample input/output are included in the package. The package is transmitted on three 1.44 MB DOS diskettes in compressed form.

**12. DATE OF ABSTRACT**

September 1995.

**KEYWORDS:** MULTIGROUP CROSS SECTIONS; MICROCOMPUTER; GAMMA-RAY
CROSS SECTIONS; NEUTRON CROSS SECTIONS; COUPLED NEUTRON-GAMMA-RAY CROSS SECTIONS