This paper presents the concept of such compensation under the form of a two-bismuth loaded plastic scintillator system: a detection scintillator interacts with photon and fast neutron radiation and is covered with metal gadolinium as a thermal neutron absorber, while an identical compensation scintillator covered with terbium solely interacts with the photon and fast neutron part of incident radiation. The authors describe the simulation-based scaling of the sensors and insulation of measurement channels, the synthesis of bismuth-loaded plastic scintillators, the experimental energy calibration of these scintillators, the nonlinear smoothing of the raw counting signals and the setting of a hypothesis test to discriminate the signal generated by the radiative signature of thermal neutron captures in gadolinium from statistical fluctuations over the compensation of both independent channels.