Effect of aging on the solubility and crystallinity of Np(IV) hydrous oxide
Description
Neptunium(IV) hydrous oxide (NpO/sub 2/ . xH/sub 2/O) was aged in aqueous suspensions with pH values ranging from 4 to 12. Initially amorphous NpO/sub 2/ . xH/sub 2/O developed strong X-ray diffraction peaks within one month that corresponded to crystalline NpO/sub 2/. The oxidation state analyses of the 1.8 nm filtered solutions showed the Np to be primarily present as Np(V). The solubility of NpO/sub 2/ . xH/sub 2/O in suspensions at pH values <8.5 followed the NpO/sub 2/ . xH/sub 2/O ↔ NpO/sub 2//sup +/ + e/sup -/ + xH/sub 2/O reaction with an apparent log K0 (after 200 days) of -10 +- 1. The results of the aqueous suspensions with pH values >8.5 were complicated by the partial conversion of the NpO/sub 2/ . xH/sub 2/O to an amorphous, oxidized Np solid, and possibly by Np aqueous speciation other than NpO/sub 2/OH0
Additional details
Publishing Information
- Publisher
- American Chemical Society.
- Imprint Place
- Washington, DC (USA)
- ISBN
- 0-8412-0827-1
- Imprint Title
- Geochemical behavior of disposed radioactive waste
- Journal Page Range
- p. 135-146.
Conference
- Title
- 185. American Chemical Society national meeting.
- Dates
- 20-25 Mar 1983.
- Place
- Seattle, WA (USA).
INIS
- Country of Publication
- United States
- Country of Input or Organization
- United States
- INIS RN
- 18095929
- Subject category
- S12: MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; S58: GEOSCIENCES; S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY;
- Resource subtype / Literary indicator
- Conference
- Descriptors DEI
- AMORPHOUS STATE; AQUEOUS SOLUTIONS; CRYSTALLIZATION; ENVIRONMENTAL TRANSPORT; FILTRATION; GEOCHEMISTRY; GROUND WATER; HIGH-LEVEL RADIOACTIVE WASTES; INTERACTIONS; NEPTUNIUM OXIDES; OXIDATION; PH VALUE; RADIOACTIVE WASTE DISPOSAL; RADIOECOLOGICAL CONCENTRATION; RADIONUCLIDE MIGRATION; SOLUBILITY; SUSPENSIONS; UNDERGROUND DISPOSAL; WATER CHEMISTRY; X-RAY DIFFRACTION
- Descriptors DEC
- ACTINIDE COMPOUNDS; CHALCOGENIDES; CHEMICAL REACTIONS; COHERENT SCATTERING; DIFFRACTION; DISPERSIONS; ECOLOGICAL CONCENTRATION; HOMOGENEOUS MIXTURES; HYDROGEN COMPOUNDS; MANAGEMENT; MASS TRANSFER; MATERIALS; MIXTURES; NEPTUNIUM COMPOUNDS; OXIDES; OXYGEN COMPOUNDS; PHASE TRANSFORMATIONS; POLAR SOLVENTS; RADIOACTIVE MATERIALS; RADIOACTIVE WASTES; SCATTERING; SEPARATION PROCESSES; SOLUTIONS; SOLVENTS; TRANSURANIUM COMPOUNDS; WASTE DISPOSAL; WASTE MANAGEMENT; WASTES; WATER; WATER TREATMENT