The International Atomic Energy Agency (IAEA) is an independent international organization with headquarters in Vienna and a membership of 130 states. The IAEA's most important task in the security policy sector is the verification of international agreements prohibiting the military use of nuclear energy, the most prominent such agreements being the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). To fulfill this task, the IAEA concludes Safeguards Agreements with the individual states and undertakes about 2,500 inspections per year. Concerning the future of the organization, one thing seems certain: the nuclear agenda will rather grow than shrink. The risks of nuclear weapons and nuclear power plants will remain; the latter may very well be aggravated through a rising demand for electricity, especially in developing countries, on the one hand, and the growing destruction of the planet's eco-system on the other. Keywords: International Atomic Energy Agency (IAEA); Non-Proliferation of Nuclear Weapons; safeguards agreements; security policy sector

IAEA – International Atomic Energy Agency

Environmental Context.Atmospheric aerosols play an important role in determining the earth’s radiative budget, climate change and air quality levels. Much effort has been spent on quantifying the impact of aerosols on climate change; however, the largest gap in our knowledge relates to quantifying natural aerosol systems and the new particle formation process associated with these systems. The marine aerosol system is of particular interest due to the 70% ocean coverage of the earth’s surface. Coastal new particle formation events are though to be more frequent and of stronger intensity compared with open ocean events and thus have been studied in detail to identify possible processes leading to open ocean new particle production. Abstract.New particle formation via secondary gas-to-particle conversion processes over the oceans is one of the main mechanisms controlling the marine aerosol number population; however, despite extensive effort over the years, this phenomenon is still not well quantified. Coastal new particle formation events are more frequent than open ocean events and consequently have been studied in greater detail. This review article summarizes the recent studies into coastal new particle formation events and summarizes the linkage of these events to iodine emissions and ultimate particle formation via iodine oxide nucleation processes. The current state of knowledge may be summarized by concluding that, in general, coastal nucleation events are driven by biogenic emissions of iodine vapours that undergo rapid chemical reactions to produce condensable iodine oxides leading to nucleation and growth of new particles. The primary source of the condensable iodine vapours is thought to be molecular iodine (I2). The role of iodine oxides in open-ocean new particle production still remains an open question and is the most pressing next step to undertake.

Coastal New Particle Formation: A Review of the Current State-Of-The-Art

LWR severe accident simulation: synthesis of the results and interpretation of the first Phebus FP experiment FPT0

ASTEC V2 severe accident integral code main features, current V2.0 modelling status, perspectives

In the aftermath of a nuclear reactor accident, understanding the release of fission products from the fuel is key.

Predicting material release during a nuclear reactor accident

Recent investigations of iodine behavior under radiolytic conditions have demonstrated that kinetics, not thermodynamics, will govern iodine speciation and partitioning under conditions typical of those expected in a reactor containment during an accident. In the presence of radiation, iodine volatility is orders of magnitude higher than that expected based on thermodynamic calculations. Kinetic studies have contributed extensively to the existing database of iodine chemistry and have several implications for modeling iodine behavior for safety analyses. For example, as a result of these investigations, many uncertainties in the iodine database, such as those regarding thermal oxidation of iodine, which were formerly regarded as reactor safety issues, are now considered to be relatively unimportant. In contrast, previously unconsidered factors, such as the effect on aqueous chemistry of impurities originating from surfaces, are now recognized as playing major roles in determining iodine volatility. An updated review of the existing literature regarding iodine behavior is provided, with a focus on recent developments. A critical evaluation of the data in the context of developing a model for iodine behavior under reactor accident conditions is also provided.

The Chemistry of Iodine in Containment

Organic impurities in containment water, originating from various painted structural surfaces and organic containment materials, could have a significant impact on iodine volatility following an ac...

The Interaction of Iodine with Organic Material in Containment

Iodine–paint interactions during nuclear reactor severe accidents

The main outcomes of the OECD Behaviour of Iodine (BIP) Project

Previous experimental work led to the development of a kinetic model that can be used to quantify iodine sorption behavior on a stainless steel surface The kinetic model, based on the mechanism proposed in earlier work, consists of four chemical reactions The model has reproduced the time-dependent adsorbed iodine concentration data on the coupons observed under various atmospheric conditions and different cycles of loading and purging The iodine adsorption kinetics were then incorporated into a mass transport equation to simulate iodine sorption behavior from a flowing air stream through a length of stainless steel tubing Discussed are the model, the simulation results, and their implications regarding the calibration of iodine transmission through long stainless steel sampling lines used for radiological monitoring of airborne iodine in a reactor containment building following an accident

Glenn A. Glowa

Papers

The Chemistry of Iodine in Containment

The Interaction of Iodine with Organic Material in Containment

Iodine–paint interactions during nuclear reactor severe accidents

The main outcomes of the OECD Behaviour of Iodine (BIP) Project

Kinetics of gaseous iodine uptake onto stainless steel during iodine-assisted corrosion