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Abstract Integral source-term analyses are performed using MELCOR for a PWR Station Blackout (SBO) sequence leading to induced steam generator tube rupture (SGTR). In the absence of any mitigation measures, such a sequence can result in a containment bypass where the radioactive materials can be released directly to the environment. In some SGTR scenarios flooding of the faulted SG secondary side with water can mitigate the accident escalation and also the release of aerosol-borne and volatile radioactive materials. Data on the efficiency of aerosol scrubbing in an SG tube bundle were obtained in the international ARTIST project. In this paper ARTIST data are used directly with parametric MELCOR analyses of a mitigated SGTR sequence to provide more realistic estimates of the releases to environment in such a type of scenario or similar. Comparison is made with predictions using the default scrubbing model in MELCOR, as a representative of the aerosol scrubbing models in current integral codes. Specifically, simulations are performed for an unmitigated sequence and 2 cases where the SG secondary was refilled at different times after the tube rupture. The results, reflecting the experimental observations from ARTIST, demonstrate enhanced aerosol retention in the highly turbulent two-phase flow conditions caused by the complex geometry of the SG secondary side. This effect is not captured by any of the models currently available. The underlying physics remains only partly understood, indicating need for further studies to support a more mechanistic treatment of the retention process.

The urban microclimate (UMC) can strongly affect the building energy demand. In this paper, the impact of the UMC on the space heating and cooling energy demand of buildings is analysed for typical office buildings in street canyon configurations, using detailed building energy simulations (BES). Convective aspects of the UMC are modelled using computational fluid dynamics (CFD) and data are transferred to BES, either by convective heat transfer coefficients or by directly coupling CFD and BES. Measured urban heat island intensities are additionally considered. Comparisons to stand-alone buildings show the large influence of the urban situation. We then outline multi-scale modelling concepts to consider UMC effects at larger urban scales, using a city energy simulation model and an adapted UMC model.

Experimental data characterizing indoor electric and magnetic fields radiated by power line communication (PLC) systems and used for the calculation of a local transfer function (coupling factor) are presented. It is shown that the indirect determination of electric field using magnetic field measurements and assuming a plane wave approximation may result in an underestimation of the electric field. Additionally, it is shown that the radiated field magnitudes vary significantly as a function of the position of the observation point and of the network load. A first evaluation of the indoor electromagnetic field radiated by PLC systems using NEC2 is presented and compared with experimental data.

We propose a merchant-regulatory framework to promote investment in the European natural gas network infrastructure based on a price cap over two-part tariffs. As suggested by Vogelsang (J Regul Econ 20:141–165, 2001) and Hogan et al. (J Regul Econ 38:113–143, 2010), a profit maximizing network operator facing this regulatory constraint will intertemporally rebalance the variable and fixed part of its two-part tariff so as to expand the congested pipelines, and converge to the Ramsey-Boiteaux equilibrium. We confirm this with actual data from the European natural gas market by comparing the bi-level price-cap model with different reference cases. We analyze the performance of the regulatory approach under different market scenarios, and identify relevant aspects that need to be addressed if the approach were to be implemented.

Empirical validation of building energy simulation tools is an important component in assessing the reliability of the simulation software. An experiment performed in conjunction with the International Energy Agency's Task 34/Annex 43 was used to assess the performance of four building energy simulation codes used to model an outdoor test cell with a glazing unit. The experiment was run for a 20-day period during October 2004, and experimental cooling powers were compared with predictions from (1) EnergyPlus, (2) DOE-2.1E, (3) TRNSYS-TUD, and (4) ESP-r. Detailed code inputs for optical and thermophysical properties as well as the impact of thermal bridges were quantified through experiments and simulations; numerous statistical parameters and sensitivity analyses were implemented to facilitate a thorough comparison of predicted and experimental cooling powers. The mean percentage differences for all four codes were: 1.9% for EnergyPlus, −3.6% for DOE-2.1E, −6.2% for TRNSYS-TUD, and 3.1% for ESP-r. The implications of various modeling procedures as well as a detailed discussion of the results are provided, specifically concerning the sensitivity of the code cooling power predictions to the selection of convective heat transfer coefficients and algorithms.

A simple framework for environmental life-cycle assessment (LCA) based on physical measures is presented and applied to the comparison of long-distance energy transport systems, including high-voltage alternating and direct current transmission lines, pipelines for gas and oil, inland waterway, road and rail transportation. Quantitative indicators for fossil-energy consumption, air-emission impacts, land use, audible noise impacts, and visual impacts are developed. These can be used in the context of existing planning or decision making instruments, such as integrated resource planning, technology assessment, LCA, regional planning, line and power plant siting. To reduce all information to a single indicator, the concept of the equivalent impacted area is introduced for land use, audible noise and visual impacts. It is shown that pipelines are the environmentally most favourable option in the case of oil and gas transport. In the case of coal transport, early conversion to electricity and transmission by high-voltage lines can lead to significant impact reductions compared to coal transport with barges and trains. For long transport distances, high-voltage direct current lines yield particularly good results.