  Type I X-ray bursts are the result of an unstable thermonuclear burning of
accreting matter on the neutron star (NS) surface. The quick release of
energetic X-ray photons during such bursts interacts with the surrounding
accretion disk, which raises the accretion rate due to Poynting-Robertson drag
and, thus, a fraction of the burst emission is reflected. We analyzed two
photospheric radius expansion bursts in the NS low-mass X-ray binary 4U
1636--536 that took place in 2017, using data from Neutron star Interior
Composition Explorer. The time-resolved burst spectra showed clear deviations
from a blackbody model. The spectral fitting can be significantly improved by
introducing either the enhanced persistent emission (the $f_a$ model) or the
reflection from the accretion disk (the \texttt{relxillNS} model). The $f_a$
model provides a higher blackbody temperature and higher burst flux compared
with the \texttt{relxillNS} model. The peak fluxes of two bursts from the $f_a$
model, $4.36\times10^{-8}~\mathrm{erg~cm^{-2}~s^{-1}}$ and
$9.10\times10^{-8}~\mathrm{erg~cm^{-2}~s^{-1}}$, are slightly higher than the
Eddington limits of mixed hydrogen-helium and pure helium bursts from previous
observations, respectively. When the disk reflections have been taken into
account simultaneously, the peak fluxes are lower to match the preferred
values. We find evidence to support the finding that both the
Poynting-Robertson drag and disk reflection have been appeared during these two
X-ray bursts. Moreover, the disk reflection may contribute $\sim20-30\%$ of the
total burst emissions.
