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The Determination of Uranium in Urine by Delayed Neutron Counting; Dosage de l'Uranium dans l'Urine par Comptage des Neutrons Differes; Opredelenie soderzhaniya urana v moche putem scheta zapazdyvayushchikh nejtronov; Determinacion del Uranio Contenido en la Orina por Recuento de Neutrones Retardados

Abstract

For this method {sup 235}U is assayed by counting delayed neutrons emitted following the fission of {sup 235}U in the sample with thermal neutrons. The three groups of neutrons of interest have half-lives of 55.72, 22.72 and 6.22 s. A 100-ml sample of urine is evaporated to dryness on a water bath. The residue is transferred with about 4-5 ml of water to a 1-oz polythene bottle which is then heat sealed. The sample bottle is put into a ''rabbit'' and sent through a pneumatic tube system to the HERALD reactor core where it is irradiated in a thermal flux of 3.94 x 10{sup 12} n cm{sup 2}/s. The sample automatically returns to the laboratory after 60 s irradiation where the sample bottle is transferred to the counter. This counter is switched on 25 s after the sample has left the reactor and counts the sample for 1 min. Blank samples consist of urine from persons occupationally unexposed to uranium and the calibration standard is a known amount of {sup 235}U (as natural uranium). The limit of detection is 0.020 pCi of 93% enriched uranium (0.007 of the maximum permissible body- burden) and 0.036 {mu}g of natural uranium per 100  More>>
Authors:
Brookes, I. R. [1] 
  1. Atomic Weapons Research Establishment, Aldermaston, Berks. (United Kingdom)
Publication Date:
Oct 15, 1965
Product Type:
Conference
Report Number:
IAEA-SM-61/6
Resource Relation:
Conference: Symposium on Radioisotope Sample Measurement Techniques in Medicine and Biology, Vienna (Austria), 24-28 May 1965; Other Information: 4 refs., 3 tabs., 6 figs.; Related Information: In: Radioisotope Sample Measurement Techniques in Medicine and Biology. Proceedings of the Symposium on Radioisotope Sample Measurement Techniques| 741 p.
Subject:
07 ISOTOPES AND RADIATION SOURCES; CALIBRATION STANDARDS; DELAYED NEUTRONS; EMISSION; ENRICHED URANIUM; HALF-LIFE; HERALD REACTOR; IRRADIATION; MAXIMUM PERMISSIBLE BODY BURDEN; NATURAL URANIUM; PLUTONIUM 239; POLYETHYLENES; THERMAL NEUTRONS; URANIUM 235; URINE
OSTI ID:
22127278
Research Organizations:
International Atomic Energy Agency, Vienna (Austria)
Country of Origin:
IAEA
Language:
English
Other Identifying Numbers:
Other: ISSN 0074-1884; TRN: XA13M2482082357
Submitting Site:
INIS
Size:
page(s) 265-280
Announcement Date:
Sep 12, 2013

Citation Formats

Brookes, I. R. The Determination of Uranium in Urine by Delayed Neutron Counting; Dosage de l'Uranium dans l'Urine par Comptage des Neutrons Differes; Opredelenie soderzhaniya urana v moche putem scheta zapazdyvayushchikh nejtronov; Determinacion del Uranio Contenido en la Orina por Recuento de Neutrones Retardados. IAEA: N. p., 1965. Web.
Brookes, I. R. The Determination of Uranium in Urine by Delayed Neutron Counting; Dosage de l'Uranium dans l'Urine par Comptage des Neutrons Differes; Opredelenie soderzhaniya urana v moche putem scheta zapazdyvayushchikh nejtronov; Determinacion del Uranio Contenido en la Orina por Recuento de Neutrones Retardados. IAEA.
Brookes, I. R. 1965. "The Determination of Uranium in Urine by Delayed Neutron Counting; Dosage de l'Uranium dans l'Urine par Comptage des Neutrons Differes; Opredelenie soderzhaniya urana v moche putem scheta zapazdyvayushchikh nejtronov; Determinacion del Uranio Contenido en la Orina por Recuento de Neutrones Retardados." IAEA.
@misc{etde_22127278,
title = {The Determination of Uranium in Urine by Delayed Neutron Counting; Dosage de l'Uranium dans l'Urine par Comptage des Neutrons Differes; Opredelenie soderzhaniya urana v moche putem scheta zapazdyvayushchikh nejtronov; Determinacion del Uranio Contenido en la Orina por Recuento de Neutrones Retardados}
author = {Brookes, I. R.}
abstractNote = {For this method {sup 235}U is assayed by counting delayed neutrons emitted following the fission of {sup 235}U in the sample with thermal neutrons. The three groups of neutrons of interest have half-lives of 55.72, 22.72 and 6.22 s. A 100-ml sample of urine is evaporated to dryness on a water bath. The residue is transferred with about 4-5 ml of water to a 1-oz polythene bottle which is then heat sealed. The sample bottle is put into a ''rabbit'' and sent through a pneumatic tube system to the HERALD reactor core where it is irradiated in a thermal flux of 3.94 x 10{sup 12} n cm{sup 2}/s. The sample automatically returns to the laboratory after 60 s irradiation where the sample bottle is transferred to the counter. This counter is switched on 25 s after the sample has left the reactor and counts the sample for 1 min. Blank samples consist of urine from persons occupationally unexposed to uranium and the calibration standard is a known amount of {sup 235}U (as natural uranium). The limit of detection is 0.020 pCi of 93% enriched uranium (0.007 of the maximum permissible body- burden) and 0.036 {mu}g of natural uranium per 100 ml of urine. The limit of detection is governed by the magnitude of the blank count. The main component of the blank is the response of the counter to {gamma}-radiation from activation products in irradiated urine. The counting and irradiation cycle takes about 3 Vulgar-Fraction-One-Half min and 50 samples at one time may be evaporated and bottled in the working day. Interference from {sup 239}Pu is likely to be negligible for the purposes of urine analysis. (author) [French] U methode decrite consiste a doser l'uranium-235 d'un echantillon en comptant les neutrons differes emis lors de la fission de {sup 235}U par neutrons thermiques. Les trois groupes de neutrons qui presentent un interet ont des periodes de 55,72, 22, 72 et 6, 22 s. On fait evaporer 100 ml d'urine au bain-marie. Le residu est transvase avec 4 a 5 ml d'eau dans un flacon en polyethylene d'une capacite de 2,85 cl, qui est scelle a chaud. Le flacon contenant l'echantillon est enferme dans un tube et envoye par un systeme pneumatique dans le coeur du reacteur HERALD ou il est irradie par un fieux de neutrons thermiques de 3,94 * 10{sup 12}n/cm{sup 2}s. Apres une irradiation de 1 min, l'echantillon retourne automatiquement au laboratoire ou le flacon contenant l'echantillon est place dans un compteur a neutrons. Ce compteur est mis en marche 25 s apres que l'echantillon a quitte le reacteur et compte l'echantillon pendant 1 min. Les echantillons temoins se composent d'urine provenant de personnes qui ne sont pas professionnellement exposees a l'uranium; l'etalon est une quantite connue de {sup 235}U (sous forme d'uranium naturel). La limite de detection est de 0,020 pCi d'uranium enrichi a 93% ou de 0,026 {mu}g d'uranium naturel (0,007 de la charge corporelle maximale admissible) et de 0,036 {mu}g d'uranium naturel pour 100 ml d'urine. Elle depend du nombre de coups correspondant aux temoins. La composante principale du temoin est la reponse du compteur aux rayons gamma emis par les produits d'activation que l'urine irradiee contient. Il faut 3,5 min environ pour irradier et compter un echantillon et l'on peut, au cours d'une journee de travail, faire evaporer et traiter 50 echantillons pour les mettre en flacons. Pour les analyses d'urine, l'influence de {sup 239}Pu peut etre consideree comme negligeable. (author) [Spanish] Con arreglo al metodo del autor, el uranio-235 se determina por recuento de los neutrones retardados emitidos a raiz de la fision por neutrones termicos del {sup 235}U contenido en la muestra. Los tres grupos de neutrones que se consideran tienen periodos de 55, 72, 22, 72 y 6, 22 s, respectivamente. En un bano Maria se evaporan a sequedad 100 mi de orina. El residuo se pasa con unos 4 a 5 mi de agua a un frasco de polietileno de 1 onza, que se cierra seguidamente por soldadura termica. El frasco con la muestra se coloca en un recipiente adecuado y se introduce por un sistema de tubos neumaticos en el nucleo del reactor HERALD, donde es irradiado en un flujo termico de 3,94 * 10{sup 12}n/cm{sup 2} s, aproximadamente. Al cabo de 1 min de irradiacion la muestra vuelve automaticamente al laboratorio, donde el frasco que la.contiene se coloca en el contador neutronico que se conecta a los 25 s de haber salido la muestra del reactor. La muestra se recuenta durante 1 min. Las muestras testigo consisten en orina de personas no expuestas profesionalmente al uranio, y el patron de calibracion, en una cantidad conocida de {sup 235}U (en forma de uranio natural). El limite de deteccion es de 0,020 pCi de uranio enriquecido al 93% (0,007 de la carga corporal maxima admisible) y 0,036 {mu}g de uranio natural por 100 mi de orina. El limite de deteccion depende de la' actividad de la muestra testigo determinada por recuento. La actividad principal de la muestra testigo se debe a los emisores gamma formados por irradiacion de la orina. El ciclo de irradiacion y recuento dura unos 3,5 min y en una jornada de trabajo se pueden evaporar y envasar 50 muestras. A los efectos del analisis de orina, es despreciable la interferencia del {sup 239}Pu. (author) [Russian] Pri jetom metode soderzhanie urana-235 opredeljaetsja putem scheta zapazdyvajushhih nejtronov, ispuskaemyh posle delenija urana-235 v obrazce teplovymi nejtronami. Tri gruppy nejtronov, predstavljajushhie interes, imejut periody poluraspada 55,72, 22,72 i 6,22 sek. 100 ml mochi isparjajut do suhogo ostatka v vodjanoj vanne. Ostatok pomeshhajut v. polijetilenovuju butylku vesom v odnu unciju vmeste primerno s 4 - 5 ml, a zatem butylku zapaivajut v gorjachem sostojanii. Butylku s obrazcom pomeshhajut v kontejner i napravljajut cherez sistemu pnevmaticheskih trub v aktivnuju zonu reaktora HERALD,gde ona obluchaetsja v potoke teplovyh nejtronov, sostavljajushhem priblizitel'no 3,94 * 10{sup 12} n/sm{sup 2} sek. Posle obluchenija v techenie odnoj minuty obrazec avtomaticheski vozvrashhaetsja v laboratoriju, gde butylku s obrazcom pomeshhajut k schetchiku nejtronov. Schetchik vkljuchajut cherez 25 sek posle togo, kak obrazec izvlechen iz reaktora i izmerjajut aktivnost' obrazca v techenie odnoj minuty. Kontrol'nye obrazcy sostojat iz mochi lic, ne podvergavshihsja professional'nomu oblucheniju uranom, a kalibrovochnyj standart sostoit iz izvestnogo kolichestva urana-235 (v vide prirodnogo urana). Predel obnaruzhenija sostavljaet 0,020 pikokjuri urana 93%-go obogashhenija (0,007 maksimal'no dopustimogo soderzhanija v organizme) i 0,036 mkg prirodnogo urana na 100 ml mochi. On opredeljaetsja velichinoj scheta izluchenija ot kontrol'nogo obrazca. Osnovnym komponentom dlja kontrol'nogo obrazca javljaetsja reakcija schetchika na gamma-izluchenie produktov aktivacii v obluchennoj moche. Schet i obluchenie odnogo obrazca zanimajut okolo 3,5 minut, i 50 obrazcov odnovremenno mozhno vyparit' i upakovat' v butylki v techenie rabochego dnja. Vlijaniem plutonija-239 pri analize mochi mozhno, po-vidimomu, prenebrech'. (author)}
place = {IAEA}
year = {1965}
month = {Oct}
}