PVIS-4: Pressure Vessel Irradiation Source.

VTT Processes, FI-02044 VTT, Finland through the OECD Nuclear Energy Agency Data Bank, Issy-les-Moulineaux, France.

Fortran 77; Linux, Unix (C00798MNYCP00).

The program prepares a fixed neutron source distribution in radial, (r,theta), (r,z) or (r,theta,z) geometry for ANISN, DORT or TORT. The user can input the source distribution in some relatively compact form (typically a few variables defining the spectrum, 10 values for the axial source distribution and, for the horizontal distribution, the values at the center and corners of each of the outermost fuel bundles and the average value for each interior bundle). The program then creates the required source arrays, such as 96*, 97* and 98* arrays for DORT.

Each required operation is performed by a separate module (a set of subprograms).

HORIHX or HORISQ takes a source distribution in the transverse plane, given at the center and corners of each fuel bundle in hexagonal or square geometry, and transforms it into (r,theta) or radial geometry. In the latter case, the output distribution may be averaged in the azimuthal direction or azimuthal maxima may be obtained.

FOUR takes an axial distribution, specified as a histogram, and approximates this with a Fourier series. This is then used to obtain a histogram distribution for a different axial mesh.

SQPIN takes a 3-D pinwise distribution in square geometry and transforms it into a radial, (r,theta), (r,z) or (r,theta,z) distribution.

FISPEC calculates a groupwise energy spectrum from any of several different functional forms. Several components with different forms may be combined into one spectrum.

COMBI combines the space and energy distributions prepared by the other modules and presents the result in a format appropriate for the SN programs in the DOORS system.

At present a reactor core of hexagonal fuel bundles must have 30- or 60-degree symmetry, a core of square bundles must have 45- or 90-degree symmetry (except if the sqpin option is used). Other core geometries are not supported for the input distribution. Only cylindrical geometry is supported for the output source distribution.

A few seconds on most computers.

Linux/Unix environments. PVIS-4 was tested at RSICC on Red Hat Linux using Intel 11.1.064 and GNU 4.5.1 Fortran Compilers, Windows 7 using Intel 11.1 Fortran and MacOS using Intel 12.0.1 and GNU 4.5.1 Fortran compilers.

Requires a Fortran 77 compiler, Linux/Unix based shell scripts.

**a. Documentation
included in package:**

“PVIS-4 - A Program Intended to Prepare a Fixed Fission Source for Pressure Vessel Irradiation Calculations with ANISN, DORT or TORT in Hexagonal or Square Geometry,” VTT Energy Technical Report RFD-2/99 (1999).

The package will be transmitted on a CD in a .tar file and contains source, sample input and output, and reference materials.

July 2012.

**KEYWORDS:** PRESSURE VESSEL EMBRITTLEMENT, SOURCE
STRENGTH, THREE DIMENSIONS, TWO DIMENSIONS