An autoclave system for uranium oxide dissolution experiments

Mikko Nykyri

Research output: Book/ReportReportProfessional

Abstract

According to the decision in principle of the Council of State of Finland the nuclear energy producers must provide preparedness for carrying out the final disposal of spent nuclear fuel in Finland. By the present principal concept the spent fuel will be disposed deep into the granitic bedrock. A parameter needed by risk analysis models is the dissolution rate of the uranium oxide matrix in the fuel pellets. In order to approach conditions prevailing deep in the groundwater, an autoclave system for dissolution experiments was developed at the Technical Research Centre of Finland. The low oxygen content and high pressure at elevated temperatures are simulated in the system. 20 MPa and 100°C are the upper operation limits of pressure and temperature. Water can be changed in the experiment autoclave without remarkable pressure and temperature variations. This has been arranged by using three pressure vessels: a supply vessel, a dissolution vessel and a depletion vessel. The extreme vessels serve pressure balancing purposes during water exchange. The water is deoxygenated during a preparation phase in the supply vessel by flushing it with nitrogen gas. Polytetrafluoroethylene is the principal material in contact with the water. A redox electrode couple was developed for potential measurements inside the dissolution vessel. The reference electrode is of Ag/AgCl-type with saturated KC1 electrolyte. A platinum wire operates as a measuring electrode.
Original languageEnglish
Place of PublicationEspoo
PublisherVTT Technical Research Centre of Finland
Number of pages24
ISBN (Print)951-38-2288-5
Publication statusPublished - 1985
MoE publication typeD4 Published development or research report or study

Publication series

NameTiedotteita / Valtion teknillinen tutkimuskeskus
PublisherVTT
Volume452

Fingerprint

Autoclaves
Uranium
Dissolution
Oxides
Spent fuels
Pressure vessels
Electrodes
Water
Experiments
Nuclear fuels
Risk analysis
Polytetrafluoroethylenes
Nuclear energy
Contacts (fluid mechanics)
Temperature
Platinum
Groundwater
Electrolytes
Wire
Nitrogen

Keywords

  • autoclaves
  • uranium
  • oxides
  • dissolving

Cite this

Nykyri, M. (1985). An autoclave system for uranium oxide dissolution experiments. Espoo: VTT Technical Research Centre of Finland. Valtion teknillinen tutkimuskeskus. Tiedotteita, No. 452
Nykyri, Mikko. / An autoclave system for uranium oxide dissolution experiments. Espoo : VTT Technical Research Centre of Finland, 1985. 24 p. (Valtion teknillinen tutkimuskeskus. Tiedotteita; No. 452).
@book{d4b2aa5bcfa145cf9e2e19c0499d4e18,
title = "An autoclave system for uranium oxide dissolution experiments",
abstract = "According to the decision in principle of the Council of State of Finland the nuclear energy producers must provide preparedness for carrying out the final disposal of spent nuclear fuel in Finland. By the present principal concept the spent fuel will be disposed deep into the granitic bedrock. A parameter needed by risk analysis models is the dissolution rate of the uranium oxide matrix in the fuel pellets. In order to approach conditions prevailing deep in the groundwater, an autoclave system for dissolution experiments was developed at the Technical Research Centre of Finland. The low oxygen content and high pressure at elevated temperatures are simulated in the system. 20 MPa and 100°C are the upper operation limits of pressure and temperature. Water can be changed in the experiment autoclave without remarkable pressure and temperature variations. This has been arranged by using three pressure vessels: a supply vessel, a dissolution vessel and a depletion vessel. The extreme vessels serve pressure balancing purposes during water exchange. The water is deoxygenated during a preparation phase in the supply vessel by flushing it with nitrogen gas. Polytetrafluoroethylene is the principal material in contact with the water. A redox electrode couple was developed for potential measurements inside the dissolution vessel. The reference electrode is of Ag/AgCl-type with saturated KC1 electrolyte. A platinum wire operates as a measuring electrode.",
keywords = "autoclaves, uranium, oxides, dissolving",
author = "Mikko Nykyri",
year = "1985",
language = "English",
isbn = "951-38-2288-5",
series = "Tiedotteita / Valtion teknillinen tutkimuskeskus",
publisher = "VTT Technical Research Centre of Finland",
address = "Finland",

}

Nykyri, M 1985, An autoclave system for uranium oxide dissolution experiments. Valtion teknillinen tutkimuskeskus. Tiedotteita, no. 452, VTT Technical Research Centre of Finland, Espoo.

An autoclave system for uranium oxide dissolution experiments. / Nykyri, Mikko.

Espoo : VTT Technical Research Centre of Finland, 1985. 24 p. (Valtion teknillinen tutkimuskeskus. Tiedotteita; No. 452).

Research output: Book/ReportReportProfessional

TY - BOOK

T1 - An autoclave system for uranium oxide dissolution experiments

AU - Nykyri, Mikko

PY - 1985

Y1 - 1985

N2 - According to the decision in principle of the Council of State of Finland the nuclear energy producers must provide preparedness for carrying out the final disposal of spent nuclear fuel in Finland. By the present principal concept the spent fuel will be disposed deep into the granitic bedrock. A parameter needed by risk analysis models is the dissolution rate of the uranium oxide matrix in the fuel pellets. In order to approach conditions prevailing deep in the groundwater, an autoclave system for dissolution experiments was developed at the Technical Research Centre of Finland. The low oxygen content and high pressure at elevated temperatures are simulated in the system. 20 MPa and 100°C are the upper operation limits of pressure and temperature. Water can be changed in the experiment autoclave without remarkable pressure and temperature variations. This has been arranged by using three pressure vessels: a supply vessel, a dissolution vessel and a depletion vessel. The extreme vessels serve pressure balancing purposes during water exchange. The water is deoxygenated during a preparation phase in the supply vessel by flushing it with nitrogen gas. Polytetrafluoroethylene is the principal material in contact with the water. A redox electrode couple was developed for potential measurements inside the dissolution vessel. The reference electrode is of Ag/AgCl-type with saturated KC1 electrolyte. A platinum wire operates as a measuring electrode.

AB - According to the decision in principle of the Council of State of Finland the nuclear energy producers must provide preparedness for carrying out the final disposal of spent nuclear fuel in Finland. By the present principal concept the spent fuel will be disposed deep into the granitic bedrock. A parameter needed by risk analysis models is the dissolution rate of the uranium oxide matrix in the fuel pellets. In order to approach conditions prevailing deep in the groundwater, an autoclave system for dissolution experiments was developed at the Technical Research Centre of Finland. The low oxygen content and high pressure at elevated temperatures are simulated in the system. 20 MPa and 100°C are the upper operation limits of pressure and temperature. Water can be changed in the experiment autoclave without remarkable pressure and temperature variations. This has been arranged by using three pressure vessels: a supply vessel, a dissolution vessel and a depletion vessel. The extreme vessels serve pressure balancing purposes during water exchange. The water is deoxygenated during a preparation phase in the supply vessel by flushing it with nitrogen gas. Polytetrafluoroethylene is the principal material in contact with the water. A redox electrode couple was developed for potential measurements inside the dissolution vessel. The reference electrode is of Ag/AgCl-type with saturated KC1 electrolyte. A platinum wire operates as a measuring electrode.

KW - autoclaves

KW - uranium

KW - oxides

KW - dissolving

M3 - Report

SN - 951-38-2288-5

T3 - Tiedotteita / Valtion teknillinen tutkimuskeskus

BT - An autoclave system for uranium oxide dissolution experiments

PB - VTT Technical Research Centre of Finland

CY - Espoo

ER -

Nykyri M. An autoclave system for uranium oxide dissolution experiments. Espoo: VTT Technical Research Centre of Finland, 1985. 24 p. (Valtion teknillinen tutkimuskeskus. Tiedotteita; No. 452).