Range of Applicability and Bias Determination for Postclosure Criticality of Commercial Spent Nuclear Fuel

The purpose of this calculation report, Range of Applicability and Bias Determination for Postclosure Criticality of Commercial Spent Nuclear Fuel, is to validate the computational method used to perform postclosure criticality calculations. The validation process applies the criticality analysis methodology approach documented in Section 3.5 of the Disposal Criticality Analysis Methodology Topical Report. The application systems for this validation consist of waste packages containing transport, aging, and disposal canisters (TAD) loaded with commercial spent nuclear fuel (CSNF) of varying assembly types, initial enrichments, and burnup values that are expected from the waste stream and of varying degree of internal component degradation that may occur over the 10,000-year regulatory time period. The criticality computational tool being evaluated is the general-purpose Monte Carlo N-Particle (MCNP) transport code. The nuclear cross-section data distributed with MCNP 5.1.40 and used to model the various physical processes are based primarily on the Evaluated Nuclear Data File/B Version VI (ENDF/B-VI) library. Criticality calculation bias and bias uncertainty and lower bound tolerance limit (LBTL) functions for CSNF waste packages are determined based on the guidance in ANSI/ANS 8.1-1998 (Ref. 4) and ANSI/ANS 8.17-2004 (Ref. 5), as described in Section 3.5.3 of Ref. 1. The development of this report is consistent with Test Plan for: Range of Applicability and Bias Determination for Postclosure Criticality. This calculation report has been developed in support of licensing activities for the proposed repository at Yucca Mountain, Nevada, and the results of the calculation may be used in the criticality evaluation for CSNF waste packages based on a conceptual TAD canister

Romanian Organic and Conventional Red Grapes Vineyards as Potential Sources of High Value-Added Products, in a Circular Economy Approach

The use of natural ingredients with active functions has been intensively studied in the last years, as a consequence to consumer preferences for organic products. Application of circular economy principles determined a significant research activity in the viticulture field. The use or re-use of vines parts for so-called nutraceuticals or other consumer-goods applications, are basically centered on their phytochemical and microbiological characterization. Eurostat updates ranks Romania fifth among the EU member states, with a total area under vines of 183,717 hectares. Characterization of four Vitis vinifera L. varieties, out of which one pure Romanian variety (Feteasca Neagra), cultivated in organic and conventional vineyards, together with pedoclimatic conditions have been provided. Data on phytochemical parameters and antimicrobial activity of extracts obtained from different anatomic parts of grapes were included. Analytical protocols and techniques applied were presented, together with data and results interpretation. Several chemometric algorithms have been used as complementary tools for interpretation of the instrumental analytical data

Automated variance reduction for Monte Carlo shielding analyses with MCNP

Variance reduction techniques are employed in Monte Carlo analyses to increase the number of particles in the space phase of interest and thereby lower the variance of statistical estimation. Variance reduction parameters are required to perform Monte Carlo calculations. It is well known that adjoint solutions, even approximate ones, are excellent biasing functions that can significantly increase the efficiency of a Monte Carlo calculation. In this study, an automated method of generating Monte Carlo variance reduction parameters, and of implementing the source energy biasing and the weight window technique in MCNP shielding calculations has been developed. The method is based on the approach used in the SAS4 module of the SCALE code system, which derives the biasing parameters from an adjoint one-dimensional Discrete Ordinates calculation. Unlike SAS4 that determines the radial and axial dose rates of a spent fuel cask in separate calculations, the present method provides energy and spatial biasing parameters for the entire system that optimize the simulation of particle transport towards all external surfaces of a spent fuel cask. The energy and spatial biasing parameters are synthesized from the adjoint fluxes of three one-dimensional Discrete Ordinates adjoint calculations. Additionally, the present method accommodates multiple source regions, such as the photon sources in light-water reactor spent nuclear fuel assemblies, in one calculation. With this automated method, detailed and accurate dose rate maps for photons, neutrons, and secondary photons outside spent fuel casks or other containers can be efficiently determined with minimal efforts.Mechanical Engineerin

Propagation of Isotopic Bias and Uncertainty to Criticality Safety Analyses of PWR Waste Packages

Burnup credit methodology is economically advantageous because significantly higher loading capacity may be achieved for spent nuclear fuel (SNF) casks based on this methodology as compared to the loading capacity based on a fresh fuel assumption. However, the criticality safety analysis for establishing the loading curve based on burnup credit becomes increasingly complex as more parameters accounting for spent fuel isotopic compositions are introduced to the safety analysis. The safety analysis requires validation of both depletion and criticality calculation methods. Validation of a neutronic-depletion code consists of quantifying the bias and the uncertainty associated with the bias in predicted SNF compositions caused by cross-section data uncertainty and by approximations in the calculational method. The validation is based on comparison between radiochemical assay (RCA) data and calculated isotopic concentrations for fuel samples representative of SNF inventory. The criticality analysis methodology for commercial SNF disposal allows burnup credit for 14 actinides and 15 fission product isotopes in SNF compositions. The neutronic-depletion method for disposal criticality analysis employing burnup credit is the two-dimensional (2-D) depletion sequence TRITON (Transport Rigor Implemented with Time-dependent Operation for Neutronic depletion)/NEWT (New ESC-based Weighting Transport code) and the 44GROUPNDF5 crosssection library in the Standardized Computer Analysis for Licensing Evaluation (SCALE 5.1) code system. The SCALE 44GROUPNDF5 cross section library is based on the Evaluated Nuclear Data File/B Version V (ENDF/B-V) library. The criticality calculation code for disposal criticality analysis employing burnup credit is General Monte Carlo N-Particle (MCNP) Transport Code. The purpose of this calculation report is to determine the bias on the calculated effective neutron multiplication factor, k{sub eff}, due to the bias and bias uncertainty associated with predicted spent fuel compositions (i.e., determine the penalty in reactivity due to isotopic composition bias and uncertainty) for use in disposal criticality analysis employing burnup credit. The method used in this calculation to propagate the isotopic bias and bias-uncertainty values to k{sub eff} is the Monte Carlo uncertainty sampling method. The development of this report is consistent with 'Test Plan for: Isotopic Validation for Postclosure Criticality of Commercial Spent Nuclear Fuel'. This calculation report has been developed in support of burnup credit activities for the proposed repository at Yucca Mountain, Nevada, and provides a methodology that can be applied to other criticality safety applications employing burnup credit

SCALE 5.1 Predictions of PWR Spent Nuclear Fuel Isotopic Compositions

The purpose of this calculation report is to document the comparison to measurement of the isotopic concentrations for pressurized water reactor (PWR) spent nuclear fuel determined with the Standardized Computer Analysis for Licensing Evaluation (SCALE) 5.1 (Ref. ) epletion calculation method. Specifically, the depletion computer code and the cross-section library being evaluated are the twodimensional (2-D) transport and depletion module, TRITON/NEWT,2, 3 and the 44GROUPNDF5 (Ref. 4) cross-section library, respectively, in the SCALE .1 code system

Phytochemical profiles, antioxidant and antibacterial activities of grape (Vitis vinifera L.) seeds and skin from organic and conventional vineyards

The therapeutic benefits of extracts obtained from different red grape fractions were thoroughly studied, however, data regarding the comparison of phytochemical extracts prepared from the same varieties coming from organic versus conventional management systems are rather lacking. The present study aimed at comparing some of the phytochemical characteristics and antimicrobial activity of hydroalcoholic (50% v/v) extracts obtained from four varieties of red grapes cultivated respectively in organic and conventional vineyards. Total flavonoid content, total phenolic compounds, and antioxidant activity were determined by molecular absorption spectroscopy. Antimicrobial activity of the studied extracts was evaluated against common bacterial strains isolated from different habitats according to specific lab procedures. The analyses were performed in solid broths by applying the disk diffusion method, which allowed for the simultaneous determination of the spectrum of the sensitivity of the tested bacteria as well as the values of the minimum inhibition concentration (MIC). It was found that favorable antagonistic activities against the tested bacteria strains were exhibited by the hydroalcoholic extracts from the seeds of the organic varieties, respectively the skin of the conventional varieties.Performan¸tă ¸si excelen¸tă în cercetarea multidisciplinară (PerExcel) | Ref. CNFIS-FDI-039

Study of the chemical composition of sweet sorghum stalks depleted in carbohydrates with applications in obtaining bioethanol

Sweet sorghum is a great energy crop that shows the benefits to ecosystems, energy and economics, being a valuable source of energy of the category 1st, 2nd and 3rd. bioethanol generation. Purpose of the paper is to study the chemical composition of sweet sorghum stalks depleted in carbohydrates with applications in obtaining ethanol. It shows appreciable compositional values of free sugars, starch, cellulose, hemicellulose and lignin. All these components can be easily made available as fermentable carbohydrates leading to the production of products with high economic value (bioethanol)

A microbial survey of the museal airborne fungal biodeteriogens

El Patrimonio cultural material está expuesto a múltiples factores ambientales de riesgo que pueden afectar a su integridad y función cultural. Estos factores pueden ser físicos, químicos y también microbiológicos. El biodeterioro producido por hongos es un conocido causante de daño estético y estructural de los materiales, con un efecto mayor en el caso de deposición inadecuada o accidentes, como inundaciones o fugas de agua. Al mismo tiempo, la contaminación del aire con diferentes esporas de hongos puede constituir un factor de riesgo para la seguridad de los bienes patrimoniales. El rastreo de la biocontaminación aérea en museos tiene una doble utilidad: protección de la salud de los trabajadores en el museo ante bio-aerosoles peligrosos y el control de la presencia de agentes biodeteriorantes capaces de descomponer las piezas del museo. El presente documento presenta la metodología utilizada para la detección de especies de hongos en el aire de un museo etnográfico en Rumania, tanto en salas de almacenamiento, como de exposición. Los resultados preliminares muestran un predominio de géneros de hongos con actividad celulolítica reconocida, tales como Aspergillus, Penicillium y Cladosporium y una correlación directa entre los valores de temperatura y humedad con la concentración y los tipos de hongos presentes en el aire. Además, los medios de cultivo utilizados para el aislamiento de las especies fúngicas del aire se mostraron como un factor importante en la metodología de aislamiento.Tangible cultural heritage is exposed to multiple environmental risk factors able to affect its integrity and cultural function. Such factors are physical, chemical and also microbiological. Fungal biodeterioration is known to cause aesthetical and structural damage to materials, the effect increasing in the case of improper depositing or accidents like floods or water leakage. At the same time, air contamination with different fungal spores can add more a risking factor for heritage goods safety. Tracing of air biocontamination has a double significance: protection of museum` workers health from hazardous bio-aerosols and the control of the presence of biodeteriogens able to decompose museum pieces. The present paper will present the methodology used for the detection of the fungal species in the air of an ethnographical museum in Romania, in storage rooms, as well as in exposition rooms. Preliminary results show the predominance of fungal genera with known cellulolytic activity, such as Aspergillus, Penicillium and Cladosporium and direct correlation between the values of temperature and humidity and the concentration and types of air cultivable fungal species. Further more, the culture media used for the isolation of the air fungal species proved to be an important factor in the isolation methodology

Adsorption of Sb (III) on Oxidized Exfoliated Graphite Nanoplatelets

In this work, Sb (III) adsorption on oxidized exfoliated graphite nanoplatelets (ox-xGnP) was evaluated for the first time, to the best of our knowledge. The ox-xGnP were characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), Brunauer⁻Emmet⁻Teller (BET) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM) equipped with energy-dispersive X-ray spectroscopy (EDX), and Zeta potential analysis. The adsorption parameters, such as pH and contact time, were optimized, and the best adsorption capacity obtained was 8.91 mg g−1 at pH = 7.0, 1.0 mg ox-xGnP/100 mL solution, T = 293 K, 1.0 mg L−1, Sb (III), 25 min contact time. The best correlation of the kinetic data was described by a pseudo-first-order kinetic model, with R2 = 0.999. The adsorption isotherms of Sb (III) onto ox-xGnP were best described by the Langmuir isotherm model. The thermodynamic parameters showed that the adsorption process was exothermic and spontaneous