  The investigation of the oscillation pattern induced by the sterile neutrinos
might determine the oscillation parameters, and at the same time, allow to
probe CPT symmetry in the leptonic sector through neutrino-antineutrino mass
inequality. We propose to use a large scintillation detector like JUNO or LENA
to detect electron neutrinos and electron antineutrinos from MCi electron
capture or beta decay sources. Our calculations indicate that such an
experiment is realistic and could be performed in parallel to the current
research plans for JUNO and RENO. Requiring at least 5$\sigma$ confidence level
and assuming the values of the oscillation parameters indicated by the current
global fit, we would be able to detect neutrino-antineutrino mass inequality of
the order of 0.5% or larger, which would imply a signal of CPT anomalies.
