SERPENT Tutorial & Guide

Continuous-energy Monte Carlo built for burnup, lattice physics, and multi-physics coupling. Practical tutorials from basic geometry to full-core depletion.

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Last Updated: April 2026

Why engineers choose Serpent

Developed by VTT, Serpent pairs high-fidelity transport with fast burnup and lattice-physics tooling.

Burnup-ready

Integrated depletion solver with detailed isotopic tracking and group constant generation for core simulators.

Efficient engine

Optimized algorithms and parallelism enable large lattice and core models without massive compute budgets.

Lattice physics output

Produce cross sections, diffusion coefficients, and perturbation data directly for deterministic workflows.

Flexible geometry

Rich CSG modeling with pin/lattice helpers plus CAD-based mesh imports for advanced studies.

Quick start guides

Installation Guide

Compile Serpent on Linux/WSL and configure cluster jobs.

First Simulation

Run your first Serpent calculation with clear commentary.

Materials & Compositions

Define isotopics, moderators, and S(α,β) options.

Geometry Modeling

Build pins, lattices, and repeated structures.

Sample Serpent Input

Here's a basic 17×17 PWR fuel assembly model demonstrating Serpent's input structure:

serpent
% --- Simple PWR fuel assembly model ---

% --- Materials:
mat fuel -10.4
92235.03c -0.04
92238.03c -0.96
8016.03c  -0.12

mat clad -6.55
40090.03c 1.0

mat water -1.0 moder lwtr 1001
1001.03c 2.0
8016.03c 1.0

% --- Geometry:
pin 1
fuel  0.4096
clad  0.4750
water

pin 2
water 0.6120

lat 10 1 0.0 0.0 17 17 1.26
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 2 1 1 2 1 1 2 1 1 1 1 1
1 1 1 2 1 1 1 1 1 1 1 1 1 2 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 2 1 1 2 1 1 2 1 1 2 1 1 2 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 2 1 1 2 1 1 2 1 1 2 1 1 2 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 2 1 1 2 1 1 2 1 1 2 1 1 2 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 2 1 1 1 1 1 1 1 1 1 2 1 1 1
1 1 1 1 1 2 1 1 2 1 1 2 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

surf 20 cuboid -10.71 10.71 -10.71 10.71 -1.0 1.0

cell 10 0 fill 10 -20
cell 20 0 outside      20

% --- Run parameters:
set pop 10000 100 40

Frequently Asked Questions

How do I obtain a Serpent license?
Licensing is handled by VTT. Academic institutions can request access through the official Serpent site, while commercial entities purchase supported seats that include updates and user support.
Which operating systems support Serpent?
Serpent compiles on Linux and runs on Windows via WSL2. Most production teams build on Linux clusters to take advantage of MPI scaling.
How does Serpent differ from MCNP or OpenMC?
Serpent specializes in reactor physics with integrated burnup, lattice physics, and perturbation capabilities. MCNP remains the general-purpose transport standard, and OpenMC focuses on a Python-first API.

Dive Into Serpent

Begin with surfaces and materials, then work up to burnup and multi-physics models.

Get Started →View Examples →