Blindaje A Neutrones

Development of New Materials for Neutron Radiation Protection
Caruncho-Rodado, J.M. (1); Fuentes-Vázquez, V.(1); Calvo, A. (1); Gómez-Rodríguez, F. (2);
González-Soto, X. (2); González-Castaño, D.M. (2); Dacuña, B. (3); Lorente, A. (4); Gallego, E. (4)
(1)

(2)

Arraela, S.L., Polígono Vilar do Colo, 15621, Cabanas, A Coruña, Spain

Grupo de Investigación en Radiofísica, Departamento deFísica de Partículas,
Facultade de Física, Universidade de Santiago de Compostela, Spain
(3)

(4)

RIAIDT, Universidade de Santiago de Compostela, Spain

Departamento de Ingeniería Nuclear, Escuela Superior de Ingenieros Industriales,
Universidad Politécnica de Madrid, Spain

Abstract
The Arraela S.L. company has developed two new materials to be used as shielding against
neutronradiation: CONTEK®RNH1 and CONTEK®RNB1. Physicochemical test were performed
on them, as well as a theoretical study of attenuation and backscattering of neutron beams of
different energies using the Monte Carlo simulation technique (MC).
CONTEK®RNH1 and CONTEK®RNB1 combine different materials that allow for both fast
neutrons brake and thermal neutron capture. On the one hand, both contain a highamount of
hydrogen (effective neutron moderator) in their structure: the former, above 2 percent
(weight) in the form of crystallized water, and the second about 7 percent (weight). On the
other hand, the mineral with which both are manufactured contains high levels of boron,
which has a great capacity for absorption of thermal neutrons.
Keywords: neutron, radiological protection, hydrogen,boron.

1. Introduction
The Arraela S.L. company has developed two new products to be used as shielding against
neutron radiation, under the brand names CONTEK®RNH1 and CONTEK®RNB1. The purpose of
this study was to analyze and characterize the behavior of both materials against neutron
radiation beams. Physicochemical tests were carried out in the RIAIDT of University of Santiago
deCompostela (USC). Simulations using the Monte Carlo method (MC) were carried out by
Grupo de Investigación en Radiofísica at USC. The neutron attenuation re sults obtained for the
two products, CONTEK®RNH1 and CONTEK®RNB1, have been compared with other materials
commonly used to slow neutron radiation, such as conventional concrete , to determine the
efficiency gains.

2. Materials and methodsCONTEK®RNH1 is a concrete product whose main mineral compound has high boron contents,
resulting in considerable neutron absorption [1]. In addition, this material contains high
crystallized water contents, which means it has a large fraction of H, a key element in stopping
and thermalizing fast neutrons [1]. The chemical composition of th e product can be seen in
Table 1:
Element
H
B
C
ONa
Al
S
Si
Ca

% Weight
2.3
12.7
0.3
60.3
0.4
0.4
0.2
3.0
20.3

Table 1. Chemical analysis of CONTEK® RNH1 obtained by experimental measurements made at RIAIDT (USC).

CONTEK®RNB1, like CONTEK®RNH1, is a material whose main mineral compound has high in
boron. As mentioned above, the high content of this element m eans the material has a high

neutron absorption capacity. Thismaterial has in its structure, and as a binder, a high amount
of hydrocarbons, resulting in a high content of H, a key element in stopping and thermaliz ing
fast neutrons. The elemental analysis of this material is shown in Table 2:

Element
H
B
O
S
Ca

% Weight
2.4
15.4
61.9
0.6
19.7

Table 2. Chemical analysis of CONTEK® RNB1.

MCNPX 2.6.0 calculations were performed tomeasure the attenuation of fered by the two
types of bricks of different thicknesses. It became a model for an 241Am-Be source and a typical
radiotherapy treatment room, a bunker with a simple maze. The geometry and the atomic
composition of the tested materials were reproduced. The attenuation properties of the two
materials were simulated both for an 241Am-Be source and for thermal neutrons,...