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[en] The present work describes the procedure carried out for the preliminary determination of neutron flux parameters for the nuclear research reactor IAN-R1 (RNI IAN-R1) through the not covered triple monitor method in the nucleus peripheral irradiation position. Using this method, the thermal flux value (φth), the epithermal neutron flux symmetry factor (α) and the ratio between thermal neutron fluxes with respect to the epithermal neutron flux (f) were estimated. Those parameters were obtained by irradiating zirconium (Zr) monitors and a gold-aluminum alloy monitors (Au-Al 0.1% Au), which were irradiated at the G3 and G4 irradiation positions of the RNI IAN-R1. The following values were found for the parameters estimated at an operating power of 30 kW, φth= 2,1 * 1011 cm2 s-1 (variance CV 4%), α = 0,02 (CV 83 %), and f =67 (CV 8 %). The high variance in α could be explained if we consider that the method only uses 3 capture reactions to describe the epithermal neutron spectrum. The variance could be improved by application of multimonitor methods for neutron flux characterization.
[en] A brief description of the radiological applications available with high intensity radiation sources is made, preceded by a short historical review of the gamma irradiation plant of the Instituto de Asuntos Nucleares. The most important researches carried out, the services given to industry, hospitals, universities and infrastructure are mentioned. Finally, some of the publications realized in the last years are summarized
[en] This document presents a historical description of the nuclear research reactor IAN-R1. A contextualization is made about the origin of the reactor within the framework of the Atoms for Peace program, including the technical characteristics and the initial configuration of the core, which was replaced by nuclear fuel MTR technology (90 %) to a new fuel type TRIGA (20 %) (acronyms of material testing reactor and training, research, isotopes, general atomics respectively). In the same way, the characteristics of the two modernization that have been made to the instrumentation and control are presented, the first oriented to the installation of three nuclear channels two of wide range and one power channel, renovation of the control console and the installation of the data acquisition system (DAC) cabinet. The second modernization, which corresponds to the new instrumentation and control of the reactor, is oriented to the change of the control console which supports the control and supervision servers, a nuclear channel NP-1000, printer, four screens of the human interface machine HMI, keyboard of the bar handling system and two keyboards for each of the servers. In addition, the DAC was replaced by the instrumentation cabinet, which includes the reactor protection systems, the redundant control system and the supervision system. The instrumentation and control is characterized by the use of the Ethernet standard to achieve inter-connectivity of the systems, programming of the human machine interface (HMI) using open source code Java, and multi platform, logical separation of functions plying concepts of distributed control and modularity, redundancy, unique failure criteria and independence. The use of the reactor is shown, referring to the irradiation facilities available for irradiation of materials to be studied using the neutron activation analysis (NAA) technique. Likewise, irradiation is planned to support the use of the fission fingerprint dating technique, research and support to educational institutions through technical conferences and a visit to the nuclear facility.
[en] From 1961 the use of nuclear energy in the industrial field in Colombia has a big advance. Today nuclear isotopes are used by private companies in this kind of application the Area of Industrial Applications and Metallurgy was the institution section that has trained and has transferred the technology needed for this purpose
[en] In this paper, the parameters thermal to epithermal neutron flux ratio (f) and thermal neutron flux (θth) are estimated (assuming α = 0) for the periphery irradiation positions (G3-G4) available at Nuclear Research Reactor IAN-R1 that belongs to the Colombian Geological Survey. This estimation was performed by measuring the induced activity, from neutron capture reactions (n, y) in two reference soils, which were irradiated (n = 4) together with Al-Au monitors. Four reference capture reactions were considered in soils, which involve isotopes of elements with certified mass fraction and 1/v behavior for cross section variation in the range of thermal neutron energy. An average value of 33 (CV = 9%) for f was found, considering 8 positions in the irradiation container; this value is comparable with measurements reported for periphery irradiation channels of TRIGA type reactors. The average thermal neutron flux determined for the 8 position of the container resulted in 1,5 *1011 ncm-2 s-1 (CV = 4 %).