  We investigate both the systematic and statistical uncertainties associated
with theoretical nuclear reaction rates of relevance during the i-process and
explore their impact on the i-process elemental production, and subsequently on
the surface enrichment, for a low-mass low-metallicity star during the early
AGB phase. We use the TALYS reaction code (Koning et al. 2023) to estimate both
the model and parameter uncertainties affecting the photon strength function
and the nuclear level densities, hence the radiative neutron capture rates. The
STAREVOL code (Siess et al. 2006) is used to determine the impact of nuclear
uncertainties on the i-process nucleosynthesis in a 1 $M_{\odot}$ [Fe/H] = -
2.5 model star during the proton ingestion event in the early AGB phase. A
large nuclear network of 1160 species coherently coupled to the transport
processes is solved to follow the i-process nucleosynthesis. We find that the
non-correlated parameter uncertainties lead the surface abundances
uncertainties of element with $Z\geq 40$ to range between 0.5 and 1.0 dex, with
odd-$Z$ elements displaying higher uncertainties. The correlated model
uncertainties are of the same order of magnitude, and both model and parameter
uncertainties have an important impact on potential observable tracers such as
Eu and La. Both the correlated model and uncorrelated parameter uncertainties
need to be estimated coherently before being propagated to astrophysical
observables through multi-zone stellar evolution models. Many reactions are
found to affect the i-process predictions and will require improved nuclear
models guided by experimental constraints. Priority should be given to the
reactions influencing the observable tracers.
