[en] The program to modernize IAN-R1 research reactor control and safety instrumentation has been carried out considering two main aspects: updating safety philosophy requirements and acquiring the newest reactor control instrumentation controlled by computer, following the present criteria internationally recognized, for safety and reliable reactor operations and the latest developments of nuclear electronic technology. The new IAN-R1 reactor instrumentation consist of two wide range neutron monitoring channels, commanded by microprocessor a data acquisition system and reactor control, (controlled by computers). The reactor control desk is providing through two displays; all safety and control signals to the reactor operators; furthermore some signals like reactor power, safety and period signals are also showed on digital bar graphics, which are hard wired directly from the neutron monitoring channels

[en] For some time the resins of ionic exchange were used for the chemical purification of water. Resins that have double function, are of special interest. They contain a cartridge, ionic channel and cationic channel. Cartridges with mixed channel resins for ionic exchange are used for purification of water in the IAN-R-1 reactor pool. After some time, cartridges lose their ionic exchange capacity and they must be replaced. This investigation is dealing with synthetic resins for ionic exchange, and focuses on standardisation of a method for separation of mixed channels. Favourable conditions were determined for the separation method and recovery of worn-out cartridges of resins for ionic exchange of mixed channel 'Barnstead supercartridges' for water purification

[en] This paper presents the neutronic analysis for the conversion of the 10 Kw IAN-R1 research reactor from HEU (90%) to LEU (20%). By changing the number of LEU plates per standard element, five different LEU prototype cores are found acceptable in excess reactivity, and deeper studies with the lowest and highest δK/K% are carried out

[en] The IAN-R1 reactor was furnished to the Government of Colombia under the 'Atoms for Peace' program by the U.S. Government. The reactor was constructed by Lockheed Aircraft Corporation and achieved initial critically at the Institute for Nuclear Studies in Bogota on 20 January, 1965. The reactor core consists of aluminum clad MTR-type plate fuel elements containing fully-enriched uranium (HEU). The reactor was initially designed to operate at a steady-state power level of 20-kW but has operated at 30-kW for the past several years. The principal applications of the reactor are radioisotope production, radiochemistry, neutron activation analysis, training, and neutron beam physics. Beginning in 1987, a program was initiated to upgrade and modernize the reactor facility. The modernization program has included replacement of the original instrumentation and control system with a new state-of-the-art microprocessor-driven digital system and addition of a new radiation monitoring system

[en] The IAN-R1 reactors has been operating by the Instituto de Asuntos Nucleares since early 1965. The reactor is used for the production of short lived radioisotopes, radiochemistry, neutron activation analysis and training. The power level is 30 kw. The reactor core consists of 16 HEU plate-type fuel elements, that have been in the core for over 26 years. At 1990 the instrumentation was replaced for a new control system with a microprocessor driven digital control console and data acquisition system. Last year it was installed a new radiation monitoring system and control rod drives with stepping motor drives. The future modifications of the reactor will include the core conversion to LEU and finally the increase of the power between 500 kw and 1 Mw

[en] Using the Monte Carlo Method a computer program has been developed to simulate the neutron radiation transport and determine the basic parameters in shielding calculations. The program has been tested comparing dose conversion factors with kerma factors issued by the international commission on radiation units and measurements (ICRU) on its report (No 26 of 1987) giving errors less than ten percent showing the goodness of the method. The program computer transmitted backscattered and absorbed flux on energy less on each collision. when neutrons are produced by region source with knowing energy; results are given like conversion factors and reliability of this program allows a wide application on radiological and medical physics

[en] Potato tubers Solatum tuberosum L. cv. Alpha were irradiated with 0.12 kgy and stored at room temperature. The endogenous hormones were extracted and determined using bioassay at dormant, budding and sprouting stages. The studied promoters were IAA, IAN, GA3 and Gibberellin like substances besides the inhibitors which included ABA and B-inhibitors. The results indicated that IAA was more sensitive to irradiation than IAN, GA3 but ABA was more stable than B-inhibitors during the dormancy. Irradiation decreased IAA and Gibberellin like substances and B-inhibitors but no change was observed in ABA content at dormant period. Irradiation caused a balance between promoters inhibitors at the end of tuber storage and after tubers sprouting