RSICC CODE PACKAGE PSR-455

RSICC CODE PACKAGE PSR-455

1. NAME and TITLE of CODE PACKAGE

MONTEBURNS 2.0: Automated, Multi-Step Monte Carlo Burnup Code System.

2. CONTRIBUTOR

Los Alamos National Laboratory, Los Alamos, New Mexico.

3. CODING LANGUAGE and COMPUTER

Fortran 77 and Perl; will work on Sun Solaris, HP Unix and WindowsNT PC systems; VMS systems are not yet fully tested (P00455MNYCP02).

4. NATURE OF PROBLEM SOLVED

MONTEBURNS Version 2 calculates coupled neutronic/isotopic results for nuclear systems and produces a large number of criticality and burnup results based on various material feed/removal specifications, power(s), and time intervals. MONTEBURNS is a fully automated tool that links the LANL MCNP Monte Carlo transport code with a radioactive decay and burnup code. Highlights on changes to Version 2 are listed in the transmittal letter. Along with other minor improvements in MONTEBURNS Version 2, the option was added to use CINDER90 instead of ORIGEN2 as the depletion/decay part of the system. CINDER90 is a multi-group depletion code developed at LANL and is not currently available from RSICC. This MONTEBURNS release was tested with various combinations of CCC-715/MCNPX 2.4.0, CCC-710/MCNP5, CCC-700/MCNP4C, CCC-371/ORIGEN2.2, ORIGEN2.1 and CINDER90. Perl is required software and is not included in this distribution. MCNP, ORIGEN2, and CINDER90 are not included.

5. METHOD of SOLUTION

MONTEBURNS processes input from the user that specifies the system geometry, initial material compositions, feed/removal specifications, and other code-specific parameters. Various results from MCNP, ORIGEN2, and other calculations are then output successively as the code runs. The principle function of MONTEBURNS is to transfer one-group cross-section and flux values from MCNP to ORIGEN2, and then transfer the resulting material compositions (after irradiation and/or decay) from ORIGEN2 back to MCNP in a repeated, cyclic fashion (a simple predictor-corrector method is used during this process).

6. RESTRICTIONS or LIMITATIONS

The basic requirement of the code is that the user have working versions of PERL, MCNP, and either CINDER90, ORIGEN2.1, or ORIGEN2.2. The code is fairly versatile and allows any number of irradiation (burn steps) to occur, up to 49 materials to be irradiated, and material to be added or removed at each step. More detailed information about limitation is in Section 8.0 of the MONTEBURNS User’s Manual (LA-UR-99-4999).

The run time for MONTEBURNS highly depends on the complexity and run time associated with the MCNP input file and the number of burn steps desired. MCNP is typically run once for each burn step. The minimum run time should be a bit longer than the amount of time it takes to run MCNP for the specific input deck specified multiplied by the number of burn steps (however, this may be increased by certain input parameters). Each of the 5 test cases may take up to 1‑2 hours each on a Sun Ultra 60.

The code has been successfully implemented on a Sun Solaris SparcStation, HP workstation, and a Windows NT system. Further, it was designed to work on any PC or UNIX machine, and possibly even a VMS system (although this has not yet been fully tested and may require modifications).

The main part of the code was written in Fortran 77; but the interface between MCNP, ORIGEN2, and monteb was written in Perl. It has been thoroughly tested on Sun Solaris and HP Unix workstations and on personal computers running Windows2000. A PC executable compiled with Digital Developer Studio Version 6.0 (Update A) under Windows 2000 is included. The system would require modifications to run on Windows95 or 98.

No non-standard options are necessary other than a platform that has a working version of MCNP and ORIGEN2.1. MCNP and ORIGEN are available from RSICC but are not included in the MONTEBURNS package. Perl is not included but can be downloaded; see www.perl.com. At RSICC, this release was tested on a Pentium IV running Windows 2000 and on an AMD Athlon MP 2000 PC running RedHat Linux 7 with The Portland Group compiler.

D. L. Poston, and H. R. Trellue, “User’s Manual, Version 2.0 for MONTEBURNS Version 1.0,” LA-UR-99-4999 (September 1999).

The package is transmitted on a CD with PDF versions of the references listed above and a GNU compressed Unix tar file that includes the MONTEBURNS Fortran source, PC executable, Perl script, and test cases. WinZIP 8.0 or later is required to extract the files under Windows.