Sosa Vera, Cristian D. (2021) Diseño de un sistema de dosimetría física para situaciones rutinarias y accidentales en reactores de investigación / Design of a physical dosimetry system for routine and accidental situation in research reactors. Maestría en Ingeniería, Universidad Nacional de Cuyo, Instituto Balseiro.
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Resumen en español
La dosimetría en campos mixtos gamma-neutrón es todavía un desafío debido a la dificultad de discriminar experimentalmente la dosis de cada componente. Para este propósito, usualmente se emplea el par de dosímetros termoluminiscentes 7"LiF: Mg, Ti (TLD-700) y 6"LiF: Mg, Ti (TLD-600). Debido a que el TLD-600 es mucho más sensible a neutrones térmicos que el TLD-700 y que ambos tienen aproximadamente la misma sensibilidad a fotones, la diferencia de las lecturas de ambos tipos de TLD puede dar información de la componente neutrónica del campo mixto. En este trabajo fue estudiado el sistema dosimétrico personal gamma-neutrón utilizado en la División Protección Radiológica del Centro Atómico Bariloche. La respuesta del dosímetro en términos de dosis equivalente personal, Hp(10), fue analizada para diferentes mediciones. Se utilizaron fuentes gamma de 137"Cs y 60"Co, mientras que para generar el campo gamma-neutrón, se usó una fuente de 241"AmBe"9. La actividad de esta última fue verificada, previo a su uso, por un método absoluto de activación de una hojuela de indio y espectrometría gamma de alta resolución. La lectura del TLD-700 pudo ser relacionada a la dosis gamma aplicando el factor de calibración gamma obtenido (0,17 ± 6% [mSv/nC]). Respecto a la dosis de neutrones, con el dosímetro estudiado se puede detectar la presencia de neutrones, pero no así cuantificar las dosis. Se concluye que, para obtener factores de calibración de neutrones, sería necesario cambiar la sala de irradiaciones por una que genere menor dispersión de neutrones. Adicionalmente, el dosímetro necesita ser modificado para diferenciar los neutrones incidentes de los de albedo (retrodispersados en el fantoma). En este trabajo se propuso un diseño de dosímetro de albedo en base a las recomendaciones del Reporte 66 de la ICRU, y una serie de pruebas para evaluar su desempeño en base a la norma ISO 21909.
Resumen en inglés
Mixed neutron-gamma field dosimetry still stands a challenge because of the difficulty to experimentally discriminate the dose from each field component. For this purpose, the pair of thermoluminescent dosemeters 7"LiF: Mg, Ti (TLD-700) and 6"LiF: Mg, Ti (TLD-600) are usually chosen. Since the TLD-600 is much more sensitive to thermal neutrons than the TLD-700 and that both have approximately the same photons sensitivity, the difference in the readings of both types of TLD can give information on the neutron component of the mixed field. In this work, the system applied for neutron-gamma personal dosimetry used in the Radiological Protection Division of the Bariloche Atomic Center was studied. The dosemeter response in terms of the personal equivalent dose, Hp(10), was analysed from different measurements. 137"Cs and 60"Co sources were used to generate the gamma radiation field, while a 241"AmBe"9 source was used to generate the gamma-neutron field. The latter´s activity was previously verified by an absolute method of activation of an indium foil and high-resolution gamma spectrometry. The TLD-700 reading could be linked to the gamma dose by applying the gamma calibration factor obtained (0.17 ± 6% [mSv/nC]). Regarding the neutron dose, with the tested dosemeter the presence of neutron doses can be detected, but not quantified. It is concluded that, in order to obtain neutron calibration factors, it would be necessary to change the irradiation room for one that generates less neutron scattering. In addition, the dosemeter needs to be modified to differentiate the incident neutrons from those of albedo (backscattered in the phantom). In this work, an albedo dosimeter design was proposed based on the recommendations of ICRU Report 66, and a series of tests to evaluate its performance based on the ISO 21909 standard.
| Tipo de objeto: | Tesis (Maestría en Ingeniería) |
|---|---|
| Palabras Clave: | Dosimetry; Dosimetría; Thermoluminescent dosemeters; Dosímetros termoluminiscentes; Research reactors; Reactores de investigación; [Radioprotection; Radioprotección; Mixed fields; Campos mixtos] |
| Referencias: | [1] ICRP, “ICRP Publication 103: The 2007 Recommendations of the International Commission on Radiological Protection,” Ann. ICRP, vol. 37, no. 2–4, 2007. [2] H. W. Julius, “Individual Monitoring for External Radiation, Some Conceptual and Practical Aspects,” Proceedings of the 9th International Congress of the IRPA. 1996. [3] W. G. Alberts et al., “Report 66,” J. Int. Comm. Radiat. Units Meas., vol. 1, no. 3, p. NP-NP, Oct. 2001, doi: 10.1093/jicru/1.3.report66. [4] ISO, “ISO 8529-1: Reference neutron radiations- Part 1: Characteristics and methods of production.” Switzerland, 2001. [5] ISO, “ISO 4037-1: X and gamma reference radiation for calibrating dosemeters and doserate meters and for determining their response as a function of photon energy - Part 1: Radiation characteristics and production methods.” Switzerland, 1996. [6] ISO, “ISO 21909: Passive personal neutron dosemeters - Performance and test requirements.” Switzerland, 2005. [7] ICRU, “Report 57,” J. Int. Comm. Radiat. Units Meas., vol. os29, no. 2, p. NP-NP, Aug. 1998, doi: 10.1093/jicru/os29.2.Report57. [8] C. A. Correa and M. A. Bisauta, “Evaluation of personal integrating dosimeters.” Accessed: Apr. 06, 2021. [Online]. Available: https://inis.iaea.org/search/search.aspx?orig_q=RN:39117955. [9] ARN, “Norma básica de seguridad radiológica,” vol. 4. AR 10.1.1, 2019. [10] M. Marques Martins, “Desenvolvimento e caracterização de um sistema de monitoração individual de nêutrons tipo albedo de duas componentes usando detectores termoluminescentes.” Tesis (Doctorado en Ciencias de la Ingeniería Nuclear). Universidad Federal de Río de Janeiro, 2008. [11] G. Portal, W. G. Cross, G. Dietze, J. R. Harvey, and R. B. Schwartz, “Report 47,” J. Int. Comm. Radiat. Units Meas., vol. os24, no. 2, p. NP-NP, Apr. 1992, doi: 10.1093/jicru/os24.2.Report47. [12] J. . Douglas, “The applications of TL materials in neutron dosimetry,” United Kingdom Atomic energy Authority, no. AERE-R-9196. Oxfordshire, 1978. [13] J. Böhm, V. N. Lebedev, and J. C. McDonald, “Performance Testing of Dosimetry Services and Its Regulatory Aspects,” Radiat. Prot. Dosimetry, vol. 54, no. 3–4, pp. 311–319, Jul. 1994, doi: 10.1093/oxfordjournals.rpd.a082356. [14] P. Andres, “Deconvolución computarizada de la curva glow de dosímetros termoluminiscentes. Aplicación en dosimetría personal y ambiental.” Tesis (Maestría en Física Médica). Universidad Nacional de Cuyo, 2009. [15] T. A. Cavalieri, V. A. Castro, and P. T. D. Siqueira, “Differences in TLD 600 and TLD 700 glow curves derived from distict mixed gamma/neutron field irradiations.” Accessed: Apr. 06, 2021. [Online]. Available: https://inis.iaea.org/search/search.aspx?orig_q=RN:45084463. [16] S. Furuta, Y. and Tanaka, “Response of 6LiF and 7LiF thermoluminescence dosimeters to fast neutrons,” Nucl. Instrum. Met., vol. 104, no. 2, pp. 365–374, 1972. [17] N. Wingate, C. L., Tochilin, E. and Goldstein, “Response of LiF to neutrons and charged particles,” Proc. Int. Conf. Lumin. Dosim., 1967. [18] Kastner J.; Oltman B. G.; Tedeschi P., “Response of LiF to fast neutrons,” Health Phys., vol. 12, no. 8, pp. 1125–1128, 1966. [19] ICRU, “Report 26,” J. Int. Comm. Radiat. Units Meas., vol. os14, no. 1, p. NP-NP, Aug. 1976, doi: 10.1093/jicru/os14.1.Report26. [20] ISO, “ISO 8529-2: Reference neutron radiations. Part 2: Calibration fundamentals of radiation protection devices related to the basic quantities characterizing the radiation field,” Switzerland, 2000. [21] IAEA, Measurement Uncertainty, no. 1585. Vienna: International Atomic Energy Agency, 2008. [22] C. Furetta, Handbook of Thermoluminescence. WORLD SCIENTIFIC, 2003. [23] IAEA, “Research Reactors Database.” https://nucleus.iaea.org/RRDB/RR/ReactorSearch.aspx (accessed Apr. 06, 2021). [24] T. Hamidouche, A. Bousbia-Salah, E. K. Si-Ahmed, and F. D’Auria, “Overview of accident analysis in nuclear research reactors,” Prog. Nucl. Energy, vol. 50, no. 1, pp. 7–14, 2008, doi: 10.1016/j.pnucene.2007.11.089. [25] ARN, “Criterios radiológicos relativos a accidentes en reactores de investigación,” vol. 2. AR 4.1.3, 2002. [26] F. D’Auria and S. Bousbia-Salah, “Accident analysis in research reactors.” Accessed: Apr. 06, 2021. [Online]. Available: https://inis.iaea.org/search/search.aspx?orig_q=RN:38111546. [27] F. C. Difilippo, “Analysis of a fatal accident in a highly enriched uranium facility,” Ann. Nucl. Energy, vol. 85, pp. 909–916, 2015, doi: 10.1016/j.anucene.2015.07.009. [28] M. S. Hodges and C. E. Sanders, “Nuclear criticality accident safety, near misses and classification,” Prog. Nucl. Energy, vol. 76, pp. 88–99, 2014, doi: 10.1016/j.pnucene.2014.05.018. [29] IAEA, “Norma de Seguridad: Seguridad de los reactores de investigación.” OIEA, Viena, 2017. [30] D. Singh, R. C. Bhatt, and U. Madhvanath, “A simple dosimetry system for nuclear accidents,” Int. J. Appl. Radiat. Isot., vol. 28, no. 5, pp. 513–519, 1977, doi: 10.1016/0020-708X(77)90187-9. [31] ARN, “Factores dosimétricos para irradiación externa y contaminación interna , y niveles de intervención para alimentos,” ARN No 36/02. Guía AR 1, 2003. [32] ISO, “ISO 8529-3: Reference neutron radiations. Part 3: Calibration of area and personal dosimeters and determination of their response as a function of neutron energy and angle of incidence,” Switzerland, 1998. [33] J. R. Taylor, An introduction to Error Analysis, Second Edi. California: University Science Books, 1997. [34] T. Haninger and G. Fehrenbacher, “Neutron dosimetry with TL albedo dosemeters at high energy accelerators,” Radiat. Prot. Dosimetry, vol. 125, no. 1–4, pp. 361–363, 2007, doi: 10.1093/rpd/ncm188. [35] J. A. Douglas and M. Marshall, “The response of some TL albedo neutron dosimeters.,” Health Phys., vol. 35, no. 2, pp. 315–324, Aug. 1978, doi: 10.1097/00004032-197808000-00015. [36] ISO, “ISO-14146: Radiation protection - Criteria and performance limits for periodic evaluation of processors of personal dosemeter for X and gamma radiation,” Switzerland, 2000. [37] R. Cruz Suárez, H. Schuhmacher, J. L. Pochat, A. Zimbal, and K. Mrabit, “Intercomparison on measurements of the quantity personal dose equivalent Hp(d) in mixed (neutron-gamma) fields--an IAEA project.,” Radiat. Prot. Dosimetry, vol. 125, no. 1–4, pp. 61–68, 2007, doi: 10.1093/rpd/ncm325. |
| Materias: | Ingeniería nuclear |
| Divisiones: | Gcia. de área de Energía Nuclear > Gcia. de Ingeniería Nuclear > Protección radiológica |
| Código ID: | 990 |
| Depositado Por: | Marisa G. Velazco Aldao |
| Depositado En: | 15 Oct 2021 12:44 |
| Última Modificación: | 15 Oct 2021 14:39 |
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