ISSSD 2016 September 24 to 28th, 2016. Tuxtla Gutiérrez, Chiapas. México. _________________________________________________________________________________________________ Radiation Portal Monitor with 10B+ZnS(Ag) Neutron Detector Performance for the Detection of Special Nuclear Materials Karen A. Guzmán-García1,*, Hector Rene Vega-Carrillo2, Eduardo Gallego1/2 Juan Antonio González3, Roberto Méndez4, Alfredo Lorente1/3 & Sviatoslv Ibañez-Fernandez1/4 1Departamento de Ingeniería Energética, ETSI Industriales Universidad Politécnica de Madrid, C. José Gutiérrez Abascal 2, 28006 Madrid, Spain 2Unidad Académica de Estudios Nucleares, Universidad Autónoma de Zacatecas C. Ciprés No. 10 98060, Zacatecas, Zac. Mexico 3Laboratorio de Ingeniería Nuclear, ETSI Caminos Canales y puertos Universidad Politécnica de Madrid, C. Prof. Aranguren 3, 28040, Madrid Spain 4Laboratorio de Patrones neutrónicos. CIEMAT, Av. Complutense 40, 28040, Madrid Spain *email:
[email protected] Abstract In homeland security, neutron detection is used to prevent the smuggling of Special Nuclear Materials. Thermal neutrons are normally detected with 3He proportional counters, in the Radiation Portal Monitors, RPMs, however due to the 3He shortage new procedures are being studied. In this work Monte Carlo methods, using the MCNP6 code, have been used to study the neutron detection features of a 10B+ZnS(Ag) under real conditions inside of a RPM. The performance for neutron detection was carried out for 252Cf, 238U and 239Pu under different conditions. In order to mimic an actual situation occurring at border areas, a sample of SNM sited inside a vehicle was simulated and the RPM with 10B+ZnS(Ag) response was calculated. At 200 cm the 10B+ZnS(Ag) on RPM response is close to 2.5 cps-ng 252Cf, when the 252Cf neutron source is shielded with 0.5 cm-thick lead and 2.5 cm-thick polyethylene fulfilling the ANSI recommendations.