Published 1990 | Version v1
Miscellaneous Metadata-only

The disequilibrium between 238U and 226Ra in the uranium determination in phosphorite

Creators

  • 1. Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear

Description

In this work, the dificults in radiometric determination of 235U and 238U isotopes by spectrometry are discussed. Techniques of measure were developed aiming to minimize problems relative to equilibrium condition. The radioactive equilibrium condition of uranium and its decay products were investigated by the 226Ra/235U relation and by the 234Th concentration. These two technique providing the uranium radiometric determination in spite of the equilibrium condition. The 226Ra/235U relation in a phosphate samples are showed. The contribution of 226Ra in the 226Ra-235U photopeak was investigated too. The precision of process was tested with intercomparison samples provided by CNEN. (author)

Availability note (English)

Available from the Library of the Comissao Nacional de Energia Nuclear, RJ, Brazil.

Abstract (Portuguese)

Neste trabalho discutem-se as dificuldades encontradas na determinacao radiometrica dos isotopos 235U e 238U, por espectrometria gama. Desenvolveram-se tecnicas de medidas que minimizaram os problemas de condicao de equilibrio. 234Th e 235U foram os radionuclideos escolhidos para determinacao da concentracao do uranio. Para investigar a condicao de equilibrio radioativo entre o uranio e seus produtos de decaimento, utilizaram-se duas maneiras: na primeira verificou-se a relacao 226Ra/235U e na segunda o 234Th. A combinacao destes metodos proporcionou a determinacao radiometrica independente da condicao de equilibrio. Os valores da relacao 226Ra/235U em amostras de fosfato e de uma amostra padrao da IAEA, sao apresentados. Investigou-se, tambem, a contribuicao do 226Ra no fotopico composto 226Ra-235U. Amostras de intercomparacao fornecidas pela CNEN, foram usadas para testar a precisao do metodo. (autor)

Additional details

Additional titles

Original title (Portuguese)
Analise do desequilibrio entre o

Publishing Information

Imprint Pagination
11 p.

Conference

Title
3. General Brazilian Congress of Nuclear Energy.
Dates
22-27 Jul 1990.
Place
Rio de Janeiro, RJ (Brazil).

INIS

Country of Publication
Brazil
Country of Input or Organization
Brazil
INIS RN
22002086
Subject category
S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY;
Resource subtype / Literary indicator
Conference, Non-conventional Literature
Descriptors DEI
NUCLEAR DECAY; PHOSPHATE ROCKS; RADIOMETRIC ANALYSIS; URANIUM
Descriptors DEC
ACTINIDES; CHEMICAL ANALYSIS; DECAY; ELEMENTS; METALS; QUANTITATIVE CHEMICAL ANALYSIS; ROCKS; SEDIMENTARY ROCKS