Related Experiment Video
Updated: Jul 17, 2026
08:57
VacuSIP, an Improved InEx Method for In Situ Measurement of Particulate and Dissolved Compounds Processed by Active Suspension Feeders
Published on: August 3, 2016
11.0K
From routine sample measurements in CEA to the Oklo phenomenon
1Commisariat à l'énergie Atomique et aux énergies alternatives (CEA), Cadarache, France.
Radiation Protection Dosimetry
|November 7, 2023
Summary
In 1972, a slight uranium-235 deficit was detected during natural uranium enrichment analysis. This prompted a comprehensive investigation into uranium mining and processing stages.
Area of Science:
- Nuclear Chemistry
- Analytical Chemistry
- Geochemistry
Background:
- In 1972, analysts at the Pierrelatte plant identified a minor discrepancy in the uranium-235 (235U) isotope abundance.
- The observed 235U enrichment level was 0.7171, falling short of the expected 0.7202.
Purpose of the Study:
- To investigate the cause of the slight 235U deficit.
- To conduct a broad analytical campaign across all stages of uranium production.
Main Methods:
- Extensive analysis of uranium samples from various mines.
- Examination of uranium at all stages of elaboration and processing.
- Utilized mass spectrometry for precise isotopic analysis at the CEA Central Analytical Laboratory.
Main Results:
- Confirmed a slight but consistent deficit in 235U across different samples.
- Identified potential variations in isotopic composition originating from different mining sources or processing steps.
Conclusions:
- The comprehensive analysis campaign was initiated to understand the source of the isotopic anomaly.
- Further investigation was recommended to pinpoint the exact cause of the 235U deficit in natural uranium destined for enrichment.
Related Concept Videos
01:19Calorimetry
When objects at different temperatures are placed in contact with each other but isolated from everything else, they attain thermal equilibrium. A container that prevents heat transfer in or out is called a calorimeter, and the use of a calorimeter to make measurements is called calorimetry. Generally, these measurements involve heat or specific heat capacity. The term "calorimetry problem" is used for any problem where the specified objects are thermally isolated from their surroundings. An...
01:21Atomic Absorption Spectroscopy: Lab
For AAS measurements, samples must be introduced as clear solutions, often requiring extensive preliminary treatment to dissolve materials like soils, animal tissues, and minerals. Common methods for sample preparation include treatment with hot mineral acids, wet ashing, combustion in closed containers, high-temperature ashing, or fusion with reagents.
Solutions containing organic solvents, such as low-molecular-mass alcohols, esters, or ketones, enhance absorbances by increasing nebulizer...
Solutions containing organic solvents, such as low-molecular-mass alcohols, esters, or ketones, enhance absorbances by increasing nebulizer...
01:20Atomic Emission Spectroscopy: Overview
Atomic emission spectroscopy (AES) is an analytical technique used to determine the elemental composition of a sample by analyzing the light emitted from excited atoms. In AES, atoms in a sample are excited to higher energy levels by thermal energy from high-temperature sources, such as plasma, arcs, or sparks. When these excited atoms return to lower energy states, they emit light at specific wavelengths characteristic of each element. The resulting atomic emission spectrum, which consists of...
01:22Atomic Emission Spectroscopy: Instrumentation
The instrumentation of atomic emission spectrometry (AES) involves various components, including atomization devices that convert samples into gas-phase atoms and ions. There are two main types of atomization devices: continuous and discrete atomizers. Continuous atomizers, like plasmas and flames, introduce samples in a constant stream, while discrete atomizers inject individual samples using syringes or autosamplers. The most common discrete atomizer is the electrothermal atomizer.
01:29Atomic Emission Spectroscopy: Lab
AES is a powerful analytical technique, especially effective when used with plasma sources, producing abundant spectra in characteristic emission lines. The Inductively Coupled Plasma (ICP), in particular, yields superior quantitative analytical data due to its high stability, low noise, low background, and minimal interferences under optimal experimental conditions. However, newer air-operated microwave sources are emerging as promising alternatives that could be more cost-effective than...
01:26Applications of EMF Measurements
Electromotive force (EMF) measurements have a broad range of applications in various fields, including chemistry and physics. The electrochemical series, an arrangement of elements in order of their standard electrode potentials, can be determined through EMF measurements. Elements with lower standard potentials can reduce ions of elements with higher standard potentials.The standard cell potential, E°, allows for the calculation of the standard reaction Gibbs energy, ΔG°, and the equilibrium...