Sorption of cesium by strontium-impregnated nuclear grade graphite at high temperature
Of the fission product nuclides generated in a typical high temperature gas-cooled reactor (HTGR), cesium exhibits the most complex transport behavior and is of primary interest, along with strontium, because of the health hazards associated with the potential release of /sup 137/Cs and /sup 90/Sr. Both of these elements are known to interact strongly with HTGR fuel element matrix and core structural graphites, exhibiting a Freundlich-type sorption behavior. In view of the fundamental interest and practical importance of assessing the behavior of cesium in nuclear grade graphite, the vapor pressure of cesium was determined as a function of cesium and strontium concentration in the reference nuclear graphite H-451. Cesium sorption isotherms were obtained at less than monolayer coverage using the pseudo-isopiestic method over the temperature range of 1073 to 1373 K and cesium vapor pressure range of 1 x 10/sup -4/ to 10 Pa. Cesium sorption isotherms were also obtained at 1273 K over a similar vapor pressure range for H-451 graphite diffusion-impregnated with strontium to concentrations ranging from 0.59 to 7.81 mmol Sr/kg graphite. The elements were tagged with /sup 137/Cs and /sup 85/Sr, and their concentrations in the graphite samples were monitored in situ. The kinetics of cesium sorption and desorption required three to 15 days to establish near-equilibrium concentrations on the graphite. Results of three models, formulated previously by Haire and Zumwalt (1973) to predict mixed-component sorption for sorbates that individually conform to Freundlich behavior, were compared with the observed equilibrium sorption behavior of cesium.
- Research Organization:
- North Carolina State Univ., Raleigh (USA)
- OSTI ID:
- 5567014
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Sorption of graphites at high temperatures. Progress report, February 1, 1976--January 31, 1977
Sorption of graphites at high temperatures. Final report, February 1, 1977-June 30, 1978. [800 to 1100/sup 0/C; pseudo-isopiestic method]
Related Subjects
CESIUM
SORPTION
GRAPHITE
SORPTIVE PROPERTIES
STRONTIUM ADDITIONS
TRACER TECHNIQUES
VAPOR PRESSURE
ALKALI METALS
ALLOYS
CARBON
ELEMENTAL MINERALS
ELEMENTS
ISOTOPE APPLICATIONS
METALS
MINERALS
NONMETALS
PHYSICAL PROPERTIES
STRONTIUM ALLOYS
SURFACE PROPERTIES
THERMODYNAMIC PROPERTIES
360603* - Materials- Properties