Download or read book Comparison of Fission Product Release Predictions Using PARFUME with Results from the AGR 1 Safety Tests written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book HTR 2014 Paper Comparison of Fission Product Release Predictions Using PARFUME with Results from the AGR 1 Safety Tests written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Safety tests were conducted on fourteen fuel compacts from AGR-1, the first irradiation experiment of the Advanced Gas Reactor (AGR) Fuel Development and Qualification program, at temperatures ranging from 1600 to 1800°C to determine fission product release at temperatures that bound reactor accident conditions. The PARFUME (PARticle FUel ModEl) code was used to predict the release of fission products silver, cesium, strontium, and krypton from fuel compacts containing tristructural isotropic (TRISO) coated particles during the safety tests, and the predicted values were compared with experimental results. Preliminary comparisons between PARFUME predictions and post-irradiation examination (PIE) results of the safety tests show an overall over-prediction of the fractional release of these fission products, which is largely attributed to an over-estimation of the diffusivities used in the modeling of fission product transport in TRISO-coated particles. Correction factors to these diffusivities were assessed for silver and cesium in order to enable a better match between the modeling predictions and the safety testing results. In the case of strontium, correction factors could not be assessed because potential release during the safety tests could not be distinguished from matrix content released during irradiation. In the case of krypton, all the coating layers are partly retentive and the available data did not allow to determine their respective retention powers, hence preventing to derive any correction factors.

Download or read book Comparison of Fission Product Release Predictions Using PARFUME with Results from the AGR 1 Irradiation Experiment written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report documents comparisons between post-irradiation examination measurements and model predictions of silver (Ag), cesium (Cs), and strontium (Sr) release from selected tristructural isotropic (TRISO) fuel particles and compacts during the first irradiation test of the Advanced Gas Reactor program that occurred from December 2006 to November 2009 in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). The modeling was performed using the particle fuel model computer code PARFUME (PARticle FUel ModEl) developed at INL. PARFUME is an advanced gas-cooled reactor fuel performance modeling and analysis code (Miller 2009). It has been developed as an integrated mechanistic code that evaluates the thermal, mechanical, and physico-chemical behavior of fuel particles during irradiation to determine the failure probability of a population of fuel particles given the particle-to-particle statistical variations in physical dimensions and material properties that arise from the fuel fabrication process, accounting for all viable mechanisms that can lead to particle failure. The code also determines the diffusion of fission products from the fuel through the particle coating layers, and through the fuel matrix to the coolant boundary. The subsequent release of fission products is calculated at the compact level (release of fission products from the compact) but it can be assessed at the particle level by adjusting the diffusivity in the fuel matrix to very high values. Furthermore, the diffusivity of each layer can be individually set to a high value (typically 10-6 m2/s) to simulate a failed layer with no capability of fission product retention. In this study, the comparison to PIE focused on fission product release and because of the lack of failure in the irradiation, the probability of particle failure was not calculated. During the AGR-1 irradiation campaign, the fuel kernel produced and released fission products, which migrated through the successive layers of the TRISO-coated particle and potentially through the compact matrix. The release of these fission products was measured in PIE and modeled with PARFUME.

Download or read book HTR 2014 Paper Comparison of Fission Product Release Predictions Using PARFUME with Results from the AGR 1 Irradiation Experiment written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The PARFUME (PARticle FUel ModEl) code was used to predict fission product release from tristructural isotropic (TRISO) coated fuel particles and compacts during the first irradiation experiment (AGR-1) of the Advanced Gas Reactor Fuel Development and Qualification program. The PARFUME model for the AGR-1 experiment used the fuel compact volume average temperature for each of the 620 days of irradiation to calculate the release of fission products silver, cesium, and strontium from a representative particle for a select number of AGR-1 compacts. Post-irradiation examination (PIE) measurements provided data on release of fission products from fuel compacts and fuel particles, and retention of fission products in the compacts outside of the SiC layer. PARFUME-predicted fractional release of these fission products was determined and compared to the PIE measurements. Results show an overall over-prediction of the fractional release of cesium by PARFUME. For particles with failed silicon carbide (SiC) layers, the over-prediction is by a factor of about two, corresponding to an over-estimation of the diffusivity in uranium oxycarbide (UCO) by a factor of about 100. For intact particles, whose release is much lower, the over-prediction is by an average of about an order of magnitude, which could additionally be attributed to an over-estimated diffusivity in SiC by about 30%. The release of strontium from intact particles is also over-estimated by PARFUME, which also points towards an over-estimated diffusivity of strontium in either SiC or UCO, or possibly both. The measured strontium fractional release from intact particles varied considerably from compact to compact, making it difficult to assess the effective over-estimation of the diffusivities. Furthermore, the release of strontium from particles with failed SiC is difficult to observe experimentally due to the release from intact particles, preventing any conclusions to be made on the accuracy or validity of the PARFUME predictions and the modeled diffusivity of strontium in UCO. In the case of silver, the comparisons between PARFUME and PIE are better than for cesium and strontium. They show a trend of over-prediction at low burnup and under-prediction at high burnup. PARFUME has limitations in the modeling of the temporal and spatial distributions of the temperature and burnup across the compacts, which affects the accuracy of its predictions. Nevertheless, the comparisons lie in the same order of magnitude.

Download or read book Field Studies of Fission Product Inhalation written by Robert G. Thomas and published by . This book was released on 1959 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A comparison of the fission product release predictions of MATREL and FASTGRASS during a severe reactor accident written by A. J. Manley and published by . This book was released on 1985 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fission Product Behavior Analytical Development Program written by S. G. Forbes and published by . This book was released on 1969 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Data Summary Report for Fission Product Release Test VI 1 written by and published by . This book was released on 1989 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Kinetics of Fission Product Release Prior to Fuel Slumping written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the primary physical/chemical models recently incorporated into a mechanistic code (FASTGRASS) for the estimation of fission product release from fuel, and compares predicted results with test data. The theory of noble gas behavior is discussed in relation to its effect on the release behavior of I, Cs, Te, Ba, and Sr. The behavior of these fission products in the presence of fuel liquefaction/dissolution and oxidation grain-growth phenomena is presented, as is the chemistry of Sr, Ba, I, and Cs. Comparison of code predictions with data indicates the following trends. Fission product release behavior from solid strongly depends on fuel microstructure, irradiation history, time at temperature, and internal fuel rod chemistry. Fuel liquefaction/dissolution, fracturing, and oxidation also exert a pronounced effect on release during fuel rod degradation. For very low burnup fuel appreciable fission product retention in previously liquefied fuel can occur due to the low concentration of fission products, and the limited growth of bubbles in the liquefied material. 24 refs., 13 figs., 9 tabs.

Download or read book Assessment of Improved Fission product Transport Models in VICTORIA Against the ORNL HI and VI Tests written by and published by . This book was released on 1991 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: New models for the release of fission-products from fuel have recently been incorporated into a comprehensive code, VICTORIA, for the prediction of radionuclide behavior under severe reactor accident conditions as an alternative to a simple Booth diffusion calculation. It is widely known that the Booth model has severe limitations when used under conditions of changing temperature and power. A new transport model based on a two node diffusive flow formulation has been implemented into VICTORIA. In addition to the diffusive flow model, other mechanisms such as grain growth, grain boundary sweeping and intergranular bubble behavior are taken into account. These physically based models focus on fission-product behavior in intact fuel geometries. While the VICTORIA program is primarily concerned with the behavior of severely degraded fuel geometries, the capability for accurately characterizing fission-product release from intact fuel must be demonstrated before other geometries can be reliably modeled. Results of VICTORIA simulations are compared with the results of in-cell heating tests on irradiated fuel. The fission-product transport models involved in these simulations are assessed and their predictive capability examined. 10 refs., 7 figs., 2 tabs.

Download or read book Comparison of fission gas release data with Supatrice 2 predictions at S G H W R fuel ratings written by C. B. Cowking and published by . This book was released on 1968 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling of Fission Products Release Using Fuzzy Reasoning written by Adel Abdelrahman and published by LAP Lambert Academic Publishing. This book was released on 2014-03 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fuzzy reasoning is used to model the fractional release of fission products under severe accidents conditions comparing with the data from out of pile experiments conducted in special annealing furnaces, performed on specimens of spent nuclear fuel with high burn up. The physical phenomena of interest are migration of fission products from the severe damaged fuel matrix and its microstructure grains with associated phenomena of sweeping of fission products from inter-granular and intra-granular sites, the increase of grain size on the account of annihilation of smaller grains during high temperature annealing, and a coalescence of pores. These phenomena can be viewed and imaged as global mass transfer of imaginary packages carrying the fission products with time. So incorporating the Package Flow Model PFM to represent the migration of the imaginary fission product packages of grains, bubbles or, pores with adjusted size during the annealing tests. The predicted values have shown a good agreement with the experimental data set from ORNL VI and HI tests, CRL experiments and, CEA experiments.

Download or read book Fission Product Behavior During the PBF Severe Fuel Damage Test 1 1 written by Jack K. Hartwell and published by . This book was released on 1987 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fission product release Signatures for LWR Fuel Rods Failed During PCM and RIA Transients written by and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper discusses fission product release from light-water-reactor-type fuel rods to the coolant loop during design basis accident tests. One of the tests was a power-cooling-mismatch test in which a single fuel rod was operated in film boiling beyond failure. Other tests discussed include reactivity initiated accident (RIA) tests, in which the fuel rods failed as a result of power bursts that produced radial-average peak fuel enthalpies ranging from 250 to 350 cal/g. One of the RIA tests used two previously irradiated fuel rods. On-line gamma spectroscopic measurements of short-lived fission products, and important aspects of fission product behavior observed during the tests, are discussed. Time-dependent release fractions for short-lived fission products are compared with release fractions suggested by: the Reactor Safety Study; NRC Regulatory Guides; and measurements from the Three Mile Island accident. Iodine behavior observed during the tests is discussed, and fuel powdering is identified as a source of particulate fission product activity, the latter of which is neglected for most accident analyses.

Download or read book A comparison of measured fission gas releases for Windscale AGR fuel irradiated above 18 GWd tU with those predicted using the computer code MINIPAT D written by N. Beatham and published by . This book was released on 1982 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Grain Boundary Sweeping and Dissolution Effects on Fission Product Behavior Under Severe Fuel Damage Accident Conditions written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The theoretical FASTGRASS-VFP model has been used in the interpretation of fission gas, iodine, tellurium, and cesium release from severe-fuel-damage (SFD) tests performed in the PBF reactor in Idaho. A theory of grain boundary sweeping of gas bubbles, gas bubble behavior during fuel liquefaction (destruction of grain boundaries due to formation of a U-rich melt phase), and during U-Zr eutectic melting has been included within the FASTGRASS-VFP formalism. The grain-boundary-sweeping theory considers the interaction between the moving grain boundary and two distinct size classes of bubbles, those on grain faces and on grain edges. The theory of the effects of fuel liquefaction and U-Zr eutectic melting on fission product behavior considers the migration and coalescence of fission gas bubbles in either molten uranium, or a zircaloy-uranium eutectic melt. The FASTGRASS-VFP predictions, measured release rates from the above tests, and previously published release rates are compared and differences between fission product behavior in trace-irradiated and in normally irradiated fuel are highlighted.

Download or read book Analysis of Fission Product Behavior in the Saclay Spitfire Loop Test SSL 1 HTGR written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The behavior of the fission metal cesium and the fission gases krypton and xenon in the Saclay Spitfire Loop SSL-1 test has been compared to that predicted using General Atomic reference data and computer code models. This is the first in a series of analyses planned in order to provide quantitative validation of HTGR fission product design methods. In this analysis, the first attempt to rigorously verify fission product design methods, the FIPERQ code was used to model the diffusion of cesium graphite and release to the coolant stream. The comparisons showed that the cesium profile shape in the graphite web and the partition coefficient between fuel rod matrix material and fuel element graphite were correctly modeled, although the overall release was significantly underpredicted. Uncertainties in the source term (fissile particle failure fraction) and total release to the coolant precluded an accurate appraisal of the validity of FIPERQ. However, several recommendations are presented to improve the applicability of future in-pile test data for the validation of fission metal release codes. The half-life dependence of fission gas release during irradiation was found to be in good agreement with the model used in the reference design materials, providing assurance that this aspect of the fission gas release predictions is properly modeled.