  CONUS is a novel experiment aiming at detecting elastic neutrino nucleus
scattering in the fully coherent regime using high-purity Germanium (Ge)
detectors and a reactor as antineutrino ($\bar\nu$) source. The detector setup
is installed at the commercial nuclear power plant in Brokdorf, Germany, at a
very small distance to the reactor core in order to guarantee a high flux of
more than 10$^{13}\bar\nu$/(s$\cdot$cm$^2$). For the experiment, a good
understanding of neutron-induced background events is required, as the neutron
recoil signals can mimic the predicted neutrino interactions. Especially
neutron-induced events correlated with the thermal power generation are
troublesome for CONUS. On-site measurements revealed the presence of a thermal
power correlated, highly thermalized neutron field with a fluence rate of
(745$\pm$30)cm$^{-2}$d$^{-1}$. These neutrons that are produced by nuclear
fission inside the reactor core, are reduced by a factor of $\sim$10$^{20}$ on
their way to the CONUS shield. With a high-purity Ge detector without shield
the $\gamma$-ray background was examined including highly thermal power
correlated $^{16}$N decay products as well as $\gamma$-lines from neutron
capture. Using the measured neutron spectrum as input, it was shown, with the
help of Monte Carlo simulations, that the thermal power correlated field is
successfully mitigated by the installed CONUS shield. The reactor-induced
background contribution in the region of interest is exceeded by the expected
signal by at least one order of magnitude assuming a realistic ionization
quenching factor of 0.2.
