\section{ALEPH2 update verification}\label{alephVal}
ALEPH2 has been updated from version 2.5, which was used for calculations of the LBE source term for the MYRRHA design revision 1.6, to the latest version 2.8. The verification of the latest ALEPH2 release for the LBE source term calculations was carried out as a part of this work and it consists of comparing the old outputs with a simulation using the new ALEPH2 version. Neutron and proton spectra were both taken from neutronic simulations of the the MYRRHA sub-critical core for the Design Revision 1.6,  to not introduce a bias due to the reactor core updates.
\begin{figure}[h]
\centering
\includegraphics[width=0.84\textwidth]{images/plots/LBE/ref.png}
\caption{Comparison between two ALEPH2 versions of the major contributors activity after 1 irradiation cycle and after 40 years of operation.}\label{ref_aleph}
\end{figure}
The major contributors to the activity are compared and their deviations are shown in Fig. \ref{ref_aleph}. The variations are lower than 1\% for the nuclides taken into account so we can conclude that the updates in the code do not affect the results for this specific case study.
\begin{center}
\fbox{\begin{minipage}{0.98\textwidth}
The ALEPH2 code update from version 2.5 to version 2.8 affects the LBE nuclide inventory predictions by less than 1\%. 
\end{minipage}
}
\end{center}