[en] Short communication

[en] For determination, nitrogen is bubbled through a solution containing radioactive Kr, Xe, Rn or another aerogen in addition to the substance determined. A continuous or intermittent addition of the titrating solution results in the release of reaction heat, thus increasing the temperature of the reaction mixture, which releases a radioactive gas. Upon reaching the equivalence point, the cold titrating reagent cools the reaction mixture, thus reducing the radioactive substance release. The equivalence point lies at the point of intersection of the extended linear parts of the curve of the dependence of released radioactivity on the volume of the titrating solution added. (M.K.)

[en] Field experiments were performed in Brittany to assess the washout coefficient Λ for molecular iodine. During each run, a few grams of non-radioactive iodine were released from a 12 meters telescopic mast, and the rain was sampled at a short distance downwind along complete transversal sections of the plume. The amount of iodine in each sample was determined by ionic chromatography to calculate the washout coefficient. In most cases, the results obtained (a few 10^-5 s^-1) are not so different as expected from the theoretical values assuming a complete solubility of iodine in rainwater. (author)

No abstract available

[en] An incident at the Department of Energy's Waste Isolation Pilot Plant (WIPP) in 2014 resulted in the release of radioactive material into the environment. Initially, it was known that at least one drum in WIPP, identified as drum 68660, was involved. However, questions remained. Could the air-monitor isotopic ratios measured in WIPP at the time of the release be explained by materials in drum 68660 or were other drums involved? Could internal conditions in drum 68660 have caused the breach? What were the implications for 68660's sister drum? These questions needed to be answered as quickly as possible. Here, this analysis, which was completed in three weeks, combined combinatorics and uncertainty analysis to provide scientists with the timely evidence they needed to either answer these important questions or to design experiments to answer them.

[en] Dispersion conditions are often inhomogeneous and instationary because of the local presence of disturbing influences. Experimental investigations in a wind tunnel allow the analysis of these disturbed dispersion conditions. Thus a realistic calculation of the atmospheric diffusion of emitted radioactive substances is possible. (author)

[en] A brief review of the work of Farmer is followed by a discussion of methods that can be used to derive quantitative safety criteria for nuclear installations in respect of normal operational and accidental releases of radionuclides

[en] ''Radio release (RR)'' technique has been found in various applications in analysis for long time ago, but not yet adapted in a continuous analyzer. This paper will describe our first development in merging the RR method to a new continuous technique, namely flow injection analysis (FIA). Instrumentation and the application of RR for vanadium determination by FIA will be discussed

[en] The air transport of radioactive materials has a very low accident risk (1000 times lower per kilometer than road) but potentially severe consequences. It is necessary to use reinforced packages. This communication examines the consequences of a severe accident to see what quantities released could be acceptably controlled. The example here is PuO₂ from reprocessed PWR fuel. Several criteria are taken into account (stochastic and non-stochastic effects, evacuation, decontamination). A value between 10 and 100 g of PuO₂ is the maximum limit for a 'manageable' release. If a package has a capacity for greater quantities, more resistant packaging should be considered. The IAEA regulation is being modified; the maximum considered quantity per package will be in the order of 20 g. (author)

[en] The monitoring is described of cement mix solidification using the radiometric emanation method. Changes in the structure and inner surface of the material can be studied directly by monitoring the release rate of a radioactive inert gas (eg., radon). The mother isotope whose decay results in radon release is incorporated in the material. The measuring equipment consists of a duct of the carrier gas entraining the released radon from the sample, of a measuring pathway in which the sample is inserted, and of a chamber containing an alpha detector. The chamber is linked to a pulse counter. The method was compared with the pulsed ultrasound method and was found to have a number of advantages, i.e., it allows the accurate determination the start and the end of solidification, monitoring hydratation processes, it can fully be automated and may be also used for small samples. (M.S.)