Determination of dissolution rates of spent fuel in carbonate solutions under different redox conditions with a flow-through experiment

ABSTRACTGaining a better understanding of the potential release behavior of water-soluble radionuclides is the focus of new laboratory spent fuel dissolution studies being planned in support of the Yucca Mountain Project. Previous studies have suggested that maximum release rates for actinide nuclides, which account for most of the long-term radioactivity in spent fuel, should be solubility-limited and should not depend on the characteristics or durability of the spent fuel waste form. Maximum actinide concentrations should be sufficiently low to meet the NRC annual release limits. Potential release rates for soluble nuclides such as 99Tc, 135Cs, 14C and 129I, which account for about 1-2% of the activity in spent fuel at 1000 years, are less certain and may depend on processes such as oxidation of the fuel in the repository air environment.Dissolution rates for several soluble nuclides have been measured from spent fuel specimens using static and semi-static methods. However, such tests do not provide a direct measurement of fuel matrix dissolution rates that may ultimately control soluble-nuclide release rates. Flow-through tests are being developed as a potential supplemental method for determining the matrix component of soluble-nuclide dissolution. Advantages and disadvantages of both semi-static and flow-through methods are discussed. Tests with fuel specimens representing a range of potential fuel states that may occur in the repository, including oxidized fuel, are proposed. Preliminary results from flow-through tests with unirradiated UO2 suggesting that matrix dissolution rates are very sensitive to water composition are also presented.

Download Full-text

Simultaneous Determination of Antidiabetic Thiazolidinediones Using Flow Through Voltammetric Sensor

Current Pharmaceutical Analysis ◽

10.2174/1573412910666140818215811 ◽

2014 ◽

Vol 10 (4) ◽

pp. 239-245 ◽

Cited By ~ 1

Author(s):

Lai-Hao Wang ◽

Yan-Lin Song

Keyword(s):

Simultaneous Determination ◽

Voltammetric Sensor ◽

Flow Through

Download Full-text

Determination of cross-sectional void fraction in a two-phase water flow through a PVC pipe

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/655/1/012024 ◽

2021 ◽

Vol 655 (1) ◽

pp. 012024

Author(s):

O.H. Ajesi ◽

M.B. Latif ◽

S.T. Gbenu ◽

C. A. Onumejor ◽

M. K. Fasasi ◽

...

Keyword(s):

Water Flow ◽

Void Fraction ◽

Two Phase ◽

Cross Sectional ◽

Flow Through ◽

Pvc Pipe ◽

Phase Water

Download Full-text

Experimental determination of noble gases and SF6, as tracers of CO2 flow through porous sandstone

Chemical Geology ◽

10.1016/j.chemgeo.2017.09.022 ◽

2018 ◽

Vol 480 ◽

pp. 93-104 ◽

Cited By ~ 11

Author(s):

R. Kilgallon ◽

S.M.V. Gilfillan ◽

K. Edlmann ◽

C.I. McDermott ◽

M. Naylor ◽

...

Keyword(s):

Experimental Determination ◽

Noble Gases ◽

Porous Sandstone ◽

Flow Through ◽

Co2 Flow

Download Full-text

A novel flow-through disk-based solid-phase extraction diffuse reflectance optrode. Application to preconcentration and determination of trace levels of nitrite

The Analyst ◽

10.1039/b104553a ◽

2001 ◽

Vol 126 (10) ◽

pp. 1740-1746 ◽

Cited By ~ 18

Author(s):

Manuel Miró ◽

José Manuel Estela ◽

Víctor Cerdà ◽

Wolfgang Frenzel

Keyword(s):

Solid Phase Extraction ◽

Diffuse Reflectance ◽

Solid Phase ◽

Phase Extraction ◽

Flow Through

Download Full-text

Flow-through pH-ISFET as detector in the determination of ammonia

Analytica Chimica Acta ◽

10.1016/s0003-2670(00)86396-5 ◽

1990 ◽

Vol 231 ◽

pp. 53-58 ◽

Cited By ~ 17

Author(s):

S. Alegret ◽

J. Alonso ◽

J. Bartroli ◽

M. del Valle ◽

N. Jaffrezic-Renault ◽

...

Keyword(s):

Flow Through

Download Full-text

Velocity Profiles of Liquid Flow Through Circular Tubes and How They Affect Flow Measurement

Journal of Solar Energy Engineering ◽

10.1115/1.2930494 ◽

1991 ◽

Vol 113 (3) ◽

pp. 206-210 ◽

Cited By ~ 1

Author(s):

D. Yogi Goswami

Keyword(s):

Transition Region ◽

Laser Doppler Velocimetry ◽

Flow Measurement ◽

Velocity Profiles ◽

Turbulent Regime ◽

Flow Meters ◽

Circular Tubes ◽

Flow Through ◽

Hydrogen Bubble Technique

This paper analyzes velocity profiles for flow through circular tubes in laminar, turbulent, and transition region flows and how they affect measurement by flow-meters. Experimental measurements of velocity profiles across the cross-section of straight circular tubes were made using laser doppler velocimetry. In addition, flow visualization was done using the hydrogen bubble technique. Velocity profiles in the laminar and the turbulent flow are quite predictable which allow the determination of meter factors for accurate flow measurement. However, the profiles can not be predicted at all in the transition region. Therefore, for the accuracy of the flowmeter, it must be ensured that the flow is completely in the laminar regime or completely in the turbulent regime. In the laminar flow a bend, even at a large distance, affects the meter factor. The paper also discusses some strategies to restructure the flow to avoid the transition region.

Download Full-text

The experimental determination of hydromagnesite precipitation rates at 22.5–75ºC

Mineralogical Magazine ◽

10.1180/minmag.2014.078.6.07 ◽

2014 ◽

Vol 78 (6) ◽

pp. 1405-1416 ◽

Cited By ~ 11

Author(s):

U.-N. Berninger ◽

G. Jordan ◽

J. Schott ◽

E. H. Oelkers

Keyword(s):

Low Temperature ◽

Experimental Determination ◽

Closed System ◽

Equilibrium Constants ◽

Magnesium Silicate ◽

Silicate Mineral ◽

Dissolution Rates ◽

Dissolution And Precipitation

Natural hydromagnesite (Mg5(CO3)4(OH)2·4H2O) dissolution and precipitation experiments were performed in closed-system reactors as a function of temperature from 22.5 to 75ºC and at 8.6 < pH < 10.7. The equilibrium constants for the reaction Mg5(CO3)4(OH)2·4H2O + 6H+ = 5Mg2+ + 4HCO3– + 6H2O were determined by bracketing the final fluid compositions obtained from the dissolution and precipitation experiments. The resulting constants were found to be 1033.7±0.9, 1030.5±0.5 and 1026.5±0.5 at 22.5, 50 and 75ºC, respectively. Whereas dissolution rates were too fast to be determined from the experiments, precipitation rates were slower and quantified. The resulting BET surface areanormalized hydromagnesite precipitation rates increase by a factor of ~2 with pH decreasing from 10.7 to 8.6. Measured rates are approximately two orders of magnitude faster than corresponding forsterite dissolution rates, suggesting that the overall rates of the low-temperature carbonation of olivine are controlled by the relatively sluggish dissolution of the magnesium silicate mineral.

Download Full-text