Published June 1979 | Version v1
Journal article Metadata-only

A polarographic determination of technetium for the irradiated nuclear fuels

Creators

  • 1. Institut National des Sciences et Techniques Nucleaires (INSTN), Centre d'Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)
  • 2. Paris-6 Univ., 75 (France)
  • 3. Ecole Nationale Superieure de Chimie, 75 - Paris (France)

Description

The electrochemical behaviour of pertechnetate TcO4- is examined as a function of pH in various media: NO3-, ethylenediaminetetraacetate, diethylenetriaminopentaacetate, phosphate, pyrophosphate and tripolyphosphate by polarography and controlled potential coulometry. The reduction step Tc(VII)/Tc(III) gives a diffusion-controlled wave for 1 < pH < 7 to 9 according to the nature of the complexing agent. The disproportionation of Tc(III) which appears at pH4 in non-complexing media is observed only for pH > 9 in complexing media, because of the stabilization of the + III oxidation state. Polarographic data permit the determination of Tc concentration in solutions of nuclear fuels after precipitation of the main interfering elements in basic media. The best results are obtained in phosphate buffered media (PO43-/HPO42- 0.1 M) in presence of chromate CrO43-. The sensitivity limit of pulse polarography is 10-6 M

Abstract (French)

Le comportement electrochimique du pertechnetate TcO4- est examine en fonction du pH dans differents milieux: NO3-, ethylenediaminetetraacetate, diethylenetriaminopentaacetate, phosphate, pyrophosphate et tripolyphosphate par polarographie et par coulometrie a potentiel controle. On montre que l'etape de reduction Tc(VII)/(Tc(III) presente une vague controlee par la diffusion de TcO4- depuis pH 1 jusqu'a pH 7 a 9 en milieu complexant. La dismutation de Tc(III), qui apparait des pH 4 en milieu non complexant, n'est observee qu'a pH > 9 en milieu complexant du fait de la stabilisation du degre d'oxydation + III. Les donnees polarographiques permettent la mise au point d'un dosage du technetium applicable aux solutions d'attaque des combustibles nucleaires apres precipitation des elements interferants sous forme d'hydroxyde. Le dosage peut etre effectue en milieu nitrate si la solution ne contient pas d'ions CrO42-. En presence de chromate, le dosage est realisable en milieu phosphate (tampon PO43-/HPO42- 0,1 M). La limite de sensibilite en polarographie a impulsions est de l'ordre de 106- M

Additional details

Additional titles

Original title (French)
Polarographie du technetium: application a la mise au point d'un dosage dans les solutions d'attaque de combustibles nucleaires irradies

Publishing Information

Journal Title
Analusis
Journal Volume
7
Journal Issue
6
Series
Analusis.
Journal Page Range
294-301
ISSN
0365-4877

INIS

Country of Publication
France
Country of Input or Organization
France
INIS RN
11512899
Subject category
S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; S11: NUCLEAR FUEL CYCLE AND FUEL MATERIALS;
Resource subtype / Literary indicator
Numerical Data
Descriptors DEI
DTPA; EDTA; EXPERIMENTAL DATA; GRAPHS; NITRATES; PERTECHNETATES; PH VALUE; PHOSPHATES; POLAROGRAPHY; QUANTITATIVE CHEMICAL ANALYSIS; REDUCTION; REPROCESSING
Descriptors DEC
AMINO ACIDS; CARBOXYLIC ACIDS; CHELATING AGENTS; CHEMICAL ANALYSIS; CHEMICAL REACTIONS; DATA; DATA FORMS; INFORMATION; NITROGEN COMPOUNDS; NUMERICAL DATA; ORGANIC ACIDS; ORGANIC COMPOUNDS; OXYGEN COMPOUNDS; PHOSPHORUS COMPOUNDS; SEPARATION PROCESSES; TECHNETIUM COMPOUNDS; TRANSITION ELEMENT COMPOUNDS