Abstract The neutron dose rate has been measured at different locations inside and outside of RP-0 reactor hall from Peruvian Institute of Nuclear Energy (IPEN); for which it was use a meted based on nuclear tracks detection leaves for charged particles produced by nuclear reaction between neutron and detector material. The used material went CR-39 polymer, to be insensitive to gamma radiation; The detection principle of neutrons is the reaction (n,p) with the nitrogen contained in air, the tracks become visible after chemical etching of polymer. The calibration of CR-39, it was carried out at the thermal column to have is a 95,5% of thermal flux, that is the what want to detect. As a result of polymer calibration, at thermal column, it was obtained the calibration factor that let obtain the value of neutron dose ((1,87 ± 0,19)x10-2 cm2 mSv), and known the irradiation time it was determ...