  Scintillating NaI(Tl) crystals are used for various rare decay experiments,
such as dark matter searches. The hygroscopicity of NaI(Tl) crystal makes the
construction of crystal detectors in these experiments challenging and requires
a tight encapsulation to prevent from air contact. More importantly, in a low
radioactivity measurement, identification of external radiations and surface
contamination is crucial to characterize the origin of total crystal
radioactivities. Studies for NaI(Tl) crystal encapsulation with active organic
scintillator vetoes have been performed to mitigate the above-mentioned issues
simultaneously. A bare crystal is directly coupled with liquid and plastic
scintillators to tag external radiations that penetrate from the outer part of
the crystal. We report the pulse shape discrimination for organic scintillator
pulses from those of the crystal scintillator in a single detector setup which
makes external gammas identifiable and long-term stability tests of the
detector setup.
