Thermal and epithermal neutron fluence rates in the irradiation facilities of the TRIGA IPR-R1 nuclear reactor

Abstract

The TRIGA IPR-R1 nuclear reactor at the Centro de Desenvolvimento da Tecnologia Nuclear CDTN/CNEN, Belo Horizonte, Brazil, has three irradiation facilities: a rotary specimen rack outside the reactor core with 40 irradiation channels which provide large scale isotope irradiation; the central tube placed at the center of the reactor core which permits sample irradiation with maximum neutron flux, as well as neutron beam extraction; a pneumatic transfer tube which makes possible the analysis of short half-life radioisotopes. The aim of this work is to evaluate the thermal and epithermal neutron fluence rates in the three irradiation facilities of the IPR-R1. Al-0.1%Au reference materials were irradiated bare and Cd-covered, at 100 kW thermal power, and gamma spectrometry was applied with an HPGe detector. For the rotary specimen rack, the values obtained for thermal and epithermal neutron fluence rates are (8.2 ± 0.2) × 10 11 n.cm −2 .s −1 and (3.5 ± 0.1) × 10 10 n.cm −2 .s −1 , respectively. For the pneumatic transfer tube and the central tube, epithermal neutron fluence rate values are respectively (3.3 ± 0.2) ×10 9 n.cm −2 .s −1 and (2.6 ± 0.1) x 10 11 n.cm −2 .s −1 . For these facilities, thermal neutron fluence rate values are (2.5 ± 0.2) × 10 11 n.cm −2 .s −1 and (2.8 ± 0.1) × 10 12 n.cm −2 .s −1 , respectively. Knowledge of these parameters will be fundamental in the planning of sample irradiation for analysis or radioisotope production in a more accurate way.

Poly(Vinyl Alcohol)/Collagen/Hydroxyapatite Nanoparticles Hybrid System Containing Yttrium-90 as a Potential Agent to Treat Osteosarcoma

“…The liquid (I.HA-Y) was analyzed by atomic emission spectrometry method with inductively coupled plasma (ICP-AES, Spectroflame-Spectro Analytical Instruments, Germany) to determinate the amount of yttrium incorporated on mesoporous HA nanoparticles. The powder was used to value the release kinetics assays during variable times (12,24,48, 72, 96 and 120 hours). Each solution was filtered using swinex system and analyzed by ICP-AES to value the amount of yttrium released from HA nanoparticles.…”

“…The yttrium activation potential by (n, γ) nuclear reaction of 89 YCl 3 (131.9 mg) was calculated following the literature [23,24] for neutron activation on TRIGA IPR-R1 nuclear reactor sited on CDTN/CNEN, Belo Horizonte, Brazil. Equation 1was feed with TRIGA reactor constants:…”

Implementación del método del triple monitor para la caracterización del flujo neutrónico del reactor nuclear de investigación IAN-R1

“…De acuerdo con lo planteado por De Corte y colaboradores [13], usando este set de monitores, y considerando que el flujo de neutrones en la región epitérmica presenta la dependencia con la energía del neutrón indicada en (4), el parámetro α puede ser calculado de acuerdo con lo indicado en (5).…”

“…En la literatura se describen tres metodologías básicas para realizar la calibración experimental de los canales de irradiación: 1) el método de relación de cadmio multimonitor, 2) el método de tres monitores no cubiertos (típicamente 197 Au, 94,96 Zr), y 3) el método de multimonitor cubierto con Cd [3,[5][6][7]. Aunque otras alternativas también han sido exploradas, como el uso de un sistema multimonitor de (Au, Cr, Mo) [8], cada una de estas metodologías implica la irradiación de sistemas de múltiples monitores y estrictas rutinas de medición, con el fin de obtener una menor incertidumbre en la estadística de conteo de los fotones emitidos por los radionúclidos formados durante el proceso de captura de neutrones.…”

Evaluation of hela cell lineage response to β radiation from Holmium-166 embedded in ceramic seeds

“…Reactor irradiation and theoretical and experimental activity measurements A set of the seeds containing Ho-165 was irradiated in a TRIGA type, 100 kW research reactor, IPR-R1 with neutron fluxes of 2.8x10 12 n/cm².s (thermal) and 2.6x10 11 n/cm².s (epithermal) (Zangirolami et al, 2010). It is important to consider the epithermal neutron flux in induced theoretical activity evaluation because the neutron absorption cross section for Ho-165 in this range of energy is higher than that for thermal neutrons.…”