Design and verification of the shielding around the new Neutron Standards Laboratory (LPN) at CIEMAT.
The construction of the new Neutron Standards Laboratory at CIEMAT (Laboratorio de Patrones Neutrónicos) has been finalised and is ready to provide service. The facility is an ∼8 m×8 m×8 m irradiation vault, following the International Organization for Standardization 8529 recommendations. It relies on several neutron sources: a 5-GBq (5.8× 10(8) s(-1)) (252)Cf source and two (241)Am-Be neutron sources (185 and 11.1 GBq). The irradiation point is located 4 m over the ground level and in the geometrical centre of the room. Each neutron source can be moved remotely from its storage position inside a water pool to the irradiation point. Prior to this, an important task to design the neutron shielding and to choose the most appropriate materials has been developed by the Radiological Security Unit and the Ionizing Radiations Metrology Laboratory. MCNPX was chosen to simulate the irradiation facility. With this information the walls were built with a thickness of 125 cm. Special attention was put on the weak points (main door, air conditioning system, etc.) so that the ambient dose outside the facility was below the regulatory limits. Finally, the Radiation Protection Unit carried out a set of measurements in specific points around the installation with an LB6411 neutron monitor and a Reuter-Stokes high-pressure ion chamber to verify experimentally the results of the simulation.
Ionizing Radiations Metrology Laboratory (LMRI), CIEMAT, Av. Complutense 40, E-28040, Madrid, España roberto.mendez@ciemat.es.
R
R
Méndez-Villafañe
Ionizing Radiations Metrology Laboratory (LMRI), CIEMAT, Av. Complutense 40, E-28040, Madrid, España.
J E
JE
Guerrero
Ionizing Radiations Metrology Laboratory (LMRI), CIEMAT, Av. Complutense 40, E-28040, Madrid, España.
M
M
Embid
Licensing and Radiological Safety Unit, CIEMAT, Av. Complutense 40, E-28040, Madrid, España.
R
R
Fernández
Licensing and Radiological Safety Unit, CIEMAT, Av. Complutense 40, E-28040, Madrid, España.
R
R
Grandio
Radiation Protection Unit, CIEMAT, Av. Complutense 40, E-28040, Madrid, España.
P
P
Pérez-Cejuela
Radiation Protection Unit, CIEMAT, Av. Complutense 40, E-28040, Madrid, España.
J L
JL
Márquez
Nuclear Innovation Unit, CIEMAT, Av. Complutense 40, E-28040, Madrid, España.
F
F
Alvarez
SEA Ingeniería, Las Rozas, 28290 Madrid, España.
P
P
Ortego
D000388:Air; D000576:Americium; D001608:Beryllium; D002138:Calibration; D002142:Californium; D003198:Computer Simulation; D004867:Equipment Design; D005160:Facility Design and Construction; D005720:Gamma Rays; D009010:Monte Carlo Method; D009502:Neutrons; D010315:Particle Accelerators; D011829:Radiation Dosage; D011835:Radiation Protection / Q000295:instrumentation* / Q000379:methods*; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods*; D013030:Spain; D014867:Water
D014867:Water; D002142:Californium; D001608:Beryllium; D000576:Americium