Activation Analysis for a He/LiPb dual Coolant Blanket for DEMO Reactor

The objective of the Spanish national project TECNO_FUS is to generate a conceptual design of a DCLL (Dual-Coolant Lithium-Lead) blanket for the DEMO fusion reactor. The dually-cooled breeding zone is composed of He/Pb-15.7 6Li and SiC as liquid metal flow channel inserts. Structural materials are ferritic-martensitic steel (Eurofer-97) for the blanket and austenitic steel (316LN) for the Vacuum Vessel (VV). The goal of this work is to analyze the radioactive waste production by the neutron-induced activation and the back-end of the blanket and the VV (SS316LN) materials (Eurofer, SiC, LiPb, and SS316LN). Furthermore, the radioactive waste production in the cryostat (SS316LN) and the bioshielding (concrete) has been estimated. Following the current approach to the back-end of the materials in fusion facilities, the radioactive waste has been subdivided according to the activity-level classification (EW, exempted waste, LILW, low and intermediate level waste, and HLW, high level waste) and according to the radiological complexity of operations (handling and cooling). The activation calculations have been carried out with the ACAB code

Comparative analysis of the alkyl breakdown products from soil humic acids by thermal and wet chemical degradation methods

6 pages. Comunicación presentada al citado simposio, celebrado del 17-20 de septiembre, 2002, en Leoben (Austria).Total amounts and distribution patterns of alkyl degradation compounds were analyzed in soil humic acids isolated from a variety of continental Mediterranean ecosystems in Central Spain. Soil physical and chemical characteristics, humic acid composition and biomarker assemblages were studied in 16 representative, undisturbed or degraded forest ecosystems including broad-leaved autochthonous forests, bush formations, cultures, pastures and pine forests. The humic acid fraction of these soils was previously characterized by routine spectroscopic methods (UV-visible, FTIR, 13C and 15N CPMAS NMR). In the present study qualitative and quantitative features of the alkyl domain of humic acids are examined by comparing the structural information provided by independent destructive techniques, with special emphasis on the mild alkaline degradation (sodium perborate) and thermal degradation by Curie-point pyrolysis.Peer reviewe

Waste Management Assessment of Candidate Materials for HiPER Reaction Chamber

One of the critical decisions in the HiPER project is to select the most appropriate material for the reaction chamber. Within this framework, we investigate the performance of different steel alloys with respect to waste management. The capabilities of commercial steels, both austenitic and ferritic/martensitic, compared to reduced-activation ferritic/martensitic steels are evaluated as for different waste management strategies (near surface burial, clearance, hands-on and remote recycling). The examined materials are: SS304, SS316, mod.9Cr-1Mo and HT9 and EUROFER. Real impurities concentrations are taken into account, and their impact is analyzed. In the study, we have assumed the most exigent HiPER 4a irradiation scenario. Commercial steels revealed to be a suitable choice for the HiPER reaction chamber, as far as their waste management options do not differ significantly from those of the reduced activation ferritic steel case. We found that for mod.9Cr-1Mo and EUROFER hands-on recycling is already possible after a cooling time shorter than 50 years and that shallow-land burial is practicable for all the steel alloys studied. The impurities present in the real heats affects the cooling time for manual recycling but not significantly. Shallow-land burial feasibility is not perturbed by the presence of impurities in the real commercial heats. Moreover, the impact of activation cross section uncertainties on the waste management assessment of the irradiated steels has been analyzed, and it is found to be of no practical significance to determine eligibility of the considered steels for the HIPER 4a reaction chamber

Dose rates evaluation of HiPER facility

During the operation of the HiPER first engineering facility, up to 1.2 × 105 MJ/yr of fusion neutrons yields are foreseen. This irradiation level could be distributed in 100 MJ detonations, accounting up to 100 detonations in a single burst, with 10 Hz repetition rate. A burst would take place every month. The dose rates are computed and different concrete shields are evaluated within the target bay. During the operation of the facility the entrance is forbidden inside the bioshield. Between bursts, manual maintenance might be performed inside the bioshield but outside the final optics assembly (FOA) shield. Inside the FOA shield the residual dose rates are so high that only remote maintenance is allowed. The FOA shield reduces the delivered dose rate to optics in a factor of 30.3

Impact of different correlation structures in cross-section covariance matrices on the inventory and inventory-related parameters

At present, cross section correlation data are very poorly known. This work can be helpful to evaluate the effort that the international community should devote to the improvement of correlation data for inventory prediction in nuclear systems. Our purpose is to assess the impact of different correlation structures on the uncertainties in relevant fuel cycle and repository parameters, using fixed variances/diagonal values in the cross section covariance matrices. At this stage, only correlation in energy is taken into account, and no correlation among different types of nuclear reactions or different isotopes is considered. To accomplish this goal, the inventory code ACAB is used to estimate the uncertainties in the actinide concentrations of the irradiated fuel, related decay heat and dose (radiotoxicity) in a representative ADS irradiation scenario. It is shown that the nature of the introduced correlations is very relevant to estimate the overall uncertainty in those parameters, and then, the need of more scientifically based correlation data is clearly justified

Application of persulfate salts for enhancing UV disinfection in marine waters

Over the years, industrial activities that generate high salinity effluents have been intensifying; this has relevant potential for causing organic and microbiological pollution which damages both human and ocean health. The development of new regulations, such as ballast water convention, encourage the development of treatment systems that can be feasible for treating seawater effluents. Accordingly, an approach based on the UV activation of persulfate salts has been assessed. In this scenario, two different persulfate sources (S2O82− and HSO5−) were evaluated under UV-C irradiation for disinfection purposes. An optimization process was performed with low chemical doses ( E. coli > E. faecalis ≈ Marine Heterotrophic Bacteria. With an evaluation of regrowth after treatment, greater cell damage was detected with the addition of persulfate salts. The major ability of regrowth for marine bacteria encourages the use of a residual disinfectant after disinfection processes

Studies of a Self Cooled Lead Lithium blanket for HiPER Reactor

Within the frame of the HiPER reactor, we propose and study a Self Cooled Lead Lithium blanket with two different cooling arrangements of the system First Wall – Blanket for the HiPER reactor: Integrated First Wall Blanket and Separated First Wall Blanket. We compare the two arrangements in terms of power cycle efficiency, operation flexibility in out-off-normal situations and proper cooling and acceptable corrosion. The Separated First Wall Blanket arrangement is superior in all of them, and it is selected as the advantageous proposal for the HiPER reactor blanket. However, it still has to be improved from the standpoint of proper cooling and corrosion rate

Los centros de fitness de la ciudad de Zaragoza

El objetivo de este trabajo es describir de forma detallada las características de los centros de fitness de la ciudad de Zaragoza (España). Un total de 19 centros participaron en el estudio y sus direcciones técnicas o equipos de coordinación, previo contacto telefónico, cumplimentaron un cuestionario creado al efecto, utilizando la herramienta Google Drive. Entre las variables del estudio se encuentran la superficie de los centros, antigüedad, número de trabajadores, cuota mensual, actividades ofertadas, actividades preferidas por los usuarios, tipos de sala de entrenamiento, realización de valoraciones funcionales o adaptación para personas con discapacidad