Uncertainty quantification applied to the radiological characterization of radioactive waste.

This paper describes the process adopted at the European Organization for Nuclear Research (CERN) to quantify uncertainties affecting the characterization of very-low-level radioactive waste. Radioactive waste is a by-product of the operation of high-energy particle accelerators. Radioactive waste must be characterized to ensure its safe disposal in final repositories. Characterizing radioactive waste means establishing the list of radionuclides together with their activities. The estimated activity levels are compared to the limits given by the national authority of the waste disposal. The quantification of the uncertainty affecting the concentration of the radionuclides is therefore essential to estimate the acceptability of the waste in the final repository but also to control the sorting, volume reduction and packaging phases of the characterization process. The characterization method consists of estimating the activity of produced radionuclides either by experimental methods or statistical approaches. The uncertainties are estimated using classical statistical methods and uncertainty propagation. A mixed multivariate random vector is built to generate random input parameters for the activity calculations. The random vector is a robust tool to account for the unknown radiological history of legacy waste. This analytical technique is also particularly useful to generate random chemical compositions of materials when the trace element concentrations are not available or cannot be measured. The methodology was validated using a waste population of legacy copper activated at CERN. The methodology introduced here represents a first approach for the uncertainty quantification (UQ) of the characterization process of waste produced at particle accelerators.

[The role of cryo-application in certain types of exudative retinal detachment]. / Le rôle de la cryoapplication dans certains types de décollement rétinien exsudatif.

The authors describe a patient with exudative retinal detachment who presented characteristics of uveal effusion syndrome and of idiopathic central serous choroidopathy. The causes and current approaches to treatment are discussed.

[Complications with rifampicin treatment: one case with anuria (author's transl)]. / Les complications du traitement à la rifampicine. A propos d'un cas avec anurie.

The authors report a new case of acute renal insufficiency with Rifampicin. They evoke the clinical background which is characteristic of these anuric tubular nephritis. They recall the different complications with Rifampicin to which they can be associated and the different mechanisms which can be at the origin of this affection as well as the difficulties to reveal them. Then, they insist on the prevention of renal accidents within the frame of our present knowledge.

[Bronchial cytology of "occult" lung cancers (author's transl)]. / La cytologie bronchique des cancers "occultes" du poumon.

Having underlined the value of bronchial cytology for the early diagnosis of lung cancers, the authors report 7 observations concerning a particular clinical form: the "occult" lung cancer with a malignant cytological precession more or less in advance in relation with the radiological or fibroscopical data. Malignant cells can be found in sputum from 9 months to 8 years beforehand. All histological types can be seen but no cancer of the anaplasic type with small cells was identified either in this series or in the literature. The authors insist also on the difficulty in localizing these cancers in situ at a very early stage. They set apart the insufficiencies of the X-ray results in several observations and the limits of other investigating techniques (bronchography, scintigraphy, echotomography, ...). These tumours seem to have a mild evolutivity.

[Nieman-Pick disease revealed by a pulmonary miliary tuberculosis (author's transl)]. / Maladie de Niemann-Pick révélée par une miliaire pulmonaire.

A diagnosis of Niemann-Pick disease was made in a 26 years old man with chronic pulmonary miliary tuberculosis and splenomegaly. It was confirmed by the drop of sphingomyelinase level in leucocytes and fibroblasts of the skin. The authors showed the presence of foamy cells with sphingomyelin in the spleen and bone marrow. They underlined the value of dosing sphingomyelinase in leucocytes for diagnosis purposes. They also observed blue histocytes in the spleen and bone marrow, next to the foamy cells which are not specific of Niemann-Pick disease and can be found in numerous other affections. This pure visceral form with delayed development without neurological involvement, corresponds to the phenotype B of Crocker.

[Tumours or mediastinal pseudo-tumours of Castleman? One observation (author's transl)]. / Tumeurs ou pseudo-tumeurs médiastinales de Castleman? A propos d'une observation.

Through a routine examination a Castleman tumour of left hilary topography was discovered in a 30 years old man. No recurrence followed exeresis. With regard to this case, the authors underlined the infrequency of these tumours with no preferential mediastinal topography and its occurrence at any age. Diagnosis is often reached after surgery by histological analysis of the tumour which enabled the distinction in two types according to Flendrig: type I plasmocytic with inflammatory signs; type II hyalino-vascular without any inflammatory signs. Surgery usually advised is not without any drawbacks because of the vascularization of the tumour and its adherence to neighbouring organs. But Castleman tumours still set nosological problems and the debate remains opened on the question of a nodal origin or a true neo-formation.