scholarly journals FY-1984 annual report: spent fuel and UO/sub 2/ source term evaluation results

1986 ◽  
Author(s):  
W.J. Gray ◽  
G.L. McVay
Keyword(s):  
Source Term ◽  
Annual Report ◽  
Spent Fuel ◽  
Term Evaluation

Analysis Of Congruent Matrix Release, Precipitation, And Time-Distributed Containment Failure On Spent Fuel Performance

1987 ◽  
Vol 112 ◽  
Author(s):  
Michael J. Apted ◽  
David W. Engel
Keyword(s):  
Source Term ◽  
Spent Fuel ◽  
Release Rates ◽  
Waste Package ◽  
Regulatory Limits ◽  
Lower Solubility ◽  
Fractional Abundance ◽  
Congruent Dissolution ◽  
Cesium 137 ◽  
Term Evaluation

AbstractThe Analytical Repository Source-Term (AREST) code has been developed for source-term evaluation of spent fuel as a final waste form in geologic repositories. AREST contains a set of analytical equations for the timedependent diffusional mass transport of both solubility-limited and inventory-limited radionuclides from a spent fuel in a failed container surrounded by a shell of packing or other porous material imbedded in a porous host rock. Three factors that affect release performance are examined: 1) congruent dissolution of the UO2 matrix, 2) chemical instability of the UO2 matrix, with precipitation of a more stable uranium phase within the waste package, and 3) the attenuation of release rate by distribution of containment failures with time.For congruent matrix dissolution, the release rates of included nuclides are proportional to the product of solubility-limited release of uranium and the fractional abundance of the nuclide. For certain conditions, congruent release rates are calculated to be up to 10 orders of magnitude lower than release rates assuming individual solubility-limits. Precipitation of a more stable, lower solubility uranium phase within the waste package is shown to increase release rates from the UO2 matrix compared to the non-precipitation case, in agreement with previous calculations. During the first 300 to 1000 years after repository closure, the distribution of containment failures with time will act to attenuate the peak average release rates of soluble, longlived nuclides, such as iodine-129, to values smaller than release rates below regulatory limits. However, for soluble nuclides with short half-lives, such as cesium-137, a broader distribution of containment failure with constant mean time of failure can actually cause an increase In the peak average release rates.

scholarly journals SNS source term evaluation program. Annual report

1974 ◽  
Author(s):  
D.K. Craig ◽  
W.C. Cannon ◽  
R.E. Filipy ◽  
D.D. Mahlum ◽  
V.H. Smith
Keyword(s):  
Source Term ◽  
Annual Report ◽  
Evaluation Program ◽  
Term Evaluation

Evaluation of source term parameters for spent fuel disposal in foreign countries

2016 ◽  
Vol 23 (1) ◽  
pp. 31-54
Author(s):  
Masanobu NAGATA ◽  
Takahiro CHIKAZAWA ◽  
Kuniaki AKAHORI ◽  
Akira KITAMURA ◽  
Yukio TACHI
Keyword(s):  
Source Term ◽  
Spent Fuel ◽  
Foreign Countries

Verification of Source Term Analysis System for Decommissioning Wastes From a CANDU Reactor

2010 ◽  
Author(s):  
Dong-Keun Cho ◽  
GwangMin Sun ◽  
JongWon Choi ◽  
Donghyeun Hwang ◽  
Hak-Soo Kim ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Source Term ◽  
Core Model ◽  
Code System ◽  
Structural Components ◽  
Evaluation Tool ◽  
Chemical Assay ◽  
Term Evaluation ◽  
Analysis System ◽  
Term Analysis

There are now twenty commercial nuclear power reactors operating as of May 2010 in South Korea. As nuclear capacity becomes higher and installations age, the Korean government and industry have launched R&D to estimate appropriate decommissioning costs of power reactors. In this paper, MCNP/ORIGEN2 code system which is being developed as a source term evaluation tool was verified by comparing the estimated nuclide inventory from MCNP/ORIGEN2 simulation with the measured nuclide inventory from chemical assay in an irradiated pressure tube discharged from Wolsong Unit 1 in 1994. Equilibrium core model of Wolsoung unit 1 was used as a neutron source to activate in-core and ex-core structural components. As a result, the estimated values from the analysis system agreed with measured data within 20% difference. Therefore, it can be concluded that MCNP/ORIGEN system could be a reliable tool to estimate source terms of decommissioning wastes from CANDU reactor, although this system assumes constant flux irradiation and snapshot equilibrium core model as a reference core.

scholarly journals An Automated SeaFAST ICP-DRC-MS Method for the Determination of 90Sr in Spent Nuclear Fuel Leachates

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1429 ◽  
Author(s):  
Víctor Vicente Vilas ◽  
Sylvain Millet ◽  
Miguel Sandow ◽  
Luis Iglesias Pérez ◽  
Daniel Serrano-Purroy ◽  
...  
Keyword(s):  
Nuclear Fuel ◽  
Safety Assessment ◽  
Analytical Approach ◽  
Source Term ◽  
Spent Nuclear Fuel ◽  
Spent Fuel ◽  
Chemical Purification ◽  
Radiochemical Method ◽  
Good Agreement

To reduce uncertainties in determining the source term and evolving condition of spent nuclear fuel is fundamental to the safety assessment. ß-emitting nuclides pose a challenging task for reliable, quantitative determination because both radiometric and mass spectrometric methodologies require prior chemical purification for the removal of interfering activity and isobars, respectively. A method for the determination of 90Sr at trace levels in nuclear spent fuel leachate samples without sophisticated and time-consuming procedures has been established. The analytical approach uses a commercially available automated pre-concentration device (SeaFAST) coupled to an ICP-DRC-MS. The method shows good performances with regard to reproducibility, precision, and LOD reducing the total time of analysis for each sample to 12.5 min. The comparison between the developed method and the classical radiochemical method shows a good agreement when taking into account the associated uncertainties.

Source Term Evaluation for Accident Transients in the Experimental Fusion Facility ITER

2015 ◽  
Vol 67 (3) ◽  
pp. 627-630 ◽  
Author(s):  
F. Virot ◽  
M. Barrachin ◽  
F. Cousin
Keyword(s):  
Source Term ◽  
Term Evaluation ◽  
Experimental Fusion
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