[en] This report describes the development of the nod-destructive nuclear material assay for ACP. The main story includes the design of ACP safeguards Neutron Counter(ASNC) by MCNP code and the test results of the prototype ASNC. The prototype ASNC is composed of 20 He-3 tubes, a high density PE, a Pb shield, a C neutron reflector and Cd neutron absorbers. Its mean neutron detection efficiency in z-axial direction is 19% and the error is 2%. These value satisfies the design criteria of 14% efficiency and 2% error. The ASNC test includes the measurement of the counting efficiency as increasing HV, the measurement of the counting efficiency and the error in z-axial direction and the HV test before/after the PDT threshold adjustment. The MCNP code calculation for the ASNC of the ACP Hot Cell is performed again because the metal ingot size is changed to 15 cm. From the MCNP code calculation, the counting efficiency is 21.7% and the error is 0.98% in z-axial direction