# Presentation: 945551

## MCNP / X  Merger

***John S. Hendricks***
***Gregg W. McKinney***
***H. Grady Hughes***
***Richard E. Prael***
***John T. Goorley***
***Los Alamos National Laboratory***
***Los Alamos, NM,87545, USA***
***ANS Annual Meeting***
***Anaheim, CA ***
***June 8 - 12, 2008***
- LA-UR-08-3475

## MCNP / X Merger Outline

- Merger Project
- Demonstration
- Implications

## MCNP / X Merger MCNP - a history of integrating codes

***MCNP / X Merger***** ****MCNP - a history of integrating codes**

**1940**

**1970**

**1980**

**1960**

**1950**

**1990**

## MCNP / X Merger MCNP / X – continued history of integrating codes

**4A, 4B**

**MCNP4C**

**LAHET**

**CEM**

**INCL**

**Cinder90**

**LAQGSM**

**MCNPX**

***MCNP / X Merger***** ****MCNP / X ****– continued history of integrating codes**

**2000**

**2005**

**2010**

**MCNP5**

**1995**

**MCNP6**

## MCNP / X MergerOverview

- Goal – combine all features of MCNP5 and MCNPX into a single code to be released as MCNP6
- Level of support: $3M
- FY07: 2.5 FTE
- FY08: 2.0 FTE
- FY09: 2.0 FTE
- Strategy: Integrate MCNPX capabilities into MCNP5 / 6 subroutine by subroutine
- Planned Milestones:
- MCNP6 at MCNP / MCNPX workshops (May 2008)
- Alpha (internal release): October 2008
- Beta (limited external release): April 2009
- RSICC Release: October 2009

## MCNP / X MergerChallenges

- ~ 1000 subroutines in 9 directories
- ~500 new subroutines in 8 sub-directories
- ~400 subroutines & modules in MCNP6
- ~400 subroutines in MCNPX /mcnpf/ directory
- ~  55 new MCNPX subroutines
- ~200 subroutines nearly the same as MCNP5
- ~150 subroutines require careful merging
- Phased approach with building & testing after each step

## MCNP / X MergerChallenges – 2 Teams / 2 Cultures

***MCNP5 Team***
- Jeremy Sweezy
- J. Tim Goorley
- Tom Booth
- Forrest B. Brown
- Jeff Bull
- Avneet Sood
- Roger Martz
- Art Forster
- Richard Prael
- Stepan Mashnik
- Tony Zukaitis

***MCNPX Team***
- Gregg W. McKinney
- Laurie S. Waters
- Joseph W. Durkee
- Jay Elson
- Michael L. Fensin
- John S. Hendricks
- Michael R. James
- Russell C. Johns
- Denise B. Pelowitz
- Franz X. Gallmeier
- M. William Johnson

## MCNP / X Merger Challenges - MCNPX 2.6.0 (April 2008)

*Integrates:** *CEM03, CINDER90, LAQGSM*** ***
***Extends MCNPX***
*Beyond 34 particles to 2205 heavy ions;*
*Beyond static nuclides to decaying & emitting;*
*Beyond fixed materials to burnup / depletion / transmutation & dynamic materials;*
*New variance reduction, sources, tallies, graphics, data*
***http://mcnpx.lanl.gov ***

## MCNP / X MergerChallenges - MCNPX 2.6.0 – Additional Capabilities

- Long file names;
- Tally stop on precision;
- Charged ions from neutron capture in table range (in addition to light-ion recoil from elastic);
- Weight-window MESH angles in radians and degrees;
- Piping PTRAK results;
- Spherical GRIDCONV;
- Proton step size control: HSTEP on M card;
- New photon emission data: PHTLIB;
- New S(α,β) scattering law;
- Differential data tallies extended to table physics;
- Separate printout/calculation of induced fission multiplicity;
- Interrupts in electron tracking;
- Extend ZAID identifiers;
- Neutron models produce light (A<4) nuclei <100 MeV;
- Additional enhancements and corrections.

## MCNP / X MergerChallenges – MCNP5 – Additional Capabilities

- Shannon Entropy for criticality convergence diagnostics;
- Pulse-height tallies with variance reduction, including DXTRAN;
- Electron physics enhancements;
- Long file names;
- Mesh tallies;
- Angles in radians and degrees;
- Prompt fission multiplicity;
- Supplemental random number generators;
- Extensive benchmark test set;
- Additional enhancements and corrections.

## MCNP / X MergerStrategy

- Phase 1
- 	Move MCNPX variables to MCNP6
- 	(reconcile particles, common, etc.)
- Phase 2
- 	First half of IMCN (card reading)
- Phase 3
- 	Second half of IMCN
- 	(geometry, tallies materials)
- Phase 4
- 	XACT (Read / process cross sections,
- 	proton library, heating)
- Phase 5
- 	MCRUN - particle transport

- Phase 6
- 	MCRUN – sources and tallies
- Phase 7
- 	Tally and cross section plots
- Phase 8
- 	Geometry plot
- Phase 9
- 	MCNPX 26 C, D, E, F, ... upgrade
- Phase 10
- 	Debug
- 	Quality control
- 	Documentation

## MCNP / X Merger Outline

- Merger Project
- Demonstration
- Implications

## MCNP / X MergerDemonstration – Proton Cross Section Plot

## MCNP / X Merger Demonstration – Photonuclear cross section plot

## MCNP / X Merger Demonstration- Geometry plot – new interactive buttons

## MCNP / X Merger Demonstration- Geometry plot – ijk indices

## MCNP / X Merger Outline

- Merger Project
- Demonstration
- Implications

## Secrets of MCNP / X Success

- It’s Free & Available
- Almost
- It Works
- Gets right answers
- It Meets Your Needs
- Repository of physics knowledge
- Reasonably easy to use

## Essentials for MCNP6 Success (prioritized)

**Leadership:**
- Jeremy E. Sweezy, Gregg W. McKinney,
- J. Tim Goorley, Laurie S. Waters
**Quality:**
- MCNPX Beta Testers
- MCNP4 / MCNPX Expert Code Review & Integration
- MCNP5 Benchmarks
- MCNP5 & MCNPX Extended Regression Test Sets
**Value**
- Free Availability
- Documentation, _*interactive*_* *Workshops
**Features** – new capabilities

## MCNP / X Merger Outline

- Merger Project – *major undertaking*
- Demonstration – *works - mostly*
- Implications – *can succeed if it embodies the best of both MCNP5/X*