Laser radiation: ocular risks and safety standards.The risk for biological tissues to be damaged by a laser beam is mainly determined by their optical properties. Laser radiations emitted in ultraviolet and infrared B and C represent a hazard for theanterior segment of the eye. Depending the wavelength, laser radiation is absorbed by the cornea, thelens or both. The lower damage thresholds are reported at the retinal level, in the spectral range of 400to 1 400 nm. The exposure limit values, recommended by laser safety standards, are evaluated withwavelength, exposure duration, pulse repetition frequency and the size of the visual angle subtending thesource. The fast evolution of laser products induces a continuous revision of guidelines. Next revisionof European standard EN 60825-1/A2 will include subnanosecond limit values, changes in the continuouswave exposure limits and a new classification of laser products susceptible to be in agreement with nextANSI and FDA/CDRH laser safety standards.

Protection quantities in external dosimetry.This paper summarises the main recommendations from the last publications of ICRP and ICRU on protection and operational quantities. The objective is to focus on the relationship of these quantitiesfor radiological protection monitoringpurposes, and to analyse the behaviour of the instrumentation used for the measurement of dose equivalentscoming from external photon and electron radiations.

Emergency treatment of pulmonary contaminations by transuranium elements. A new galenic form of Na3CaDTPA.The emergency treatment of pulmonary contamination by plutonium and transuranium elements needs the early use of a chelator, the Na3CaDTPA under monocalcic trisodic form. The local administration ofthe active principle is carried out by an appliance, the Spinhaler$^{\circledR}$, which delivers theactive principle under micronised form without any propelled gas. The French Military Health Service isthe manufacturer which produces this treatment and has studied a modification of the galenic form ofNa3CaDTPA to improve the intrapulmonary distribution. This treatment, without any secondary effect, isproposed even for a presumed pulmonary contamination. Its easy use allows an early administration for alarge number of people supposed to be contaminated. However, it cannot take the place of the other formsof treatment, especially intraveinous, which needs a medical prescription in case of an establishedcontamination.

>Methodology for rehabilitation strategies evaluation aid after an accident: application and results.Post-accidental management is a matter for an optimisation process in a multicriteria context, which has to combine quantitative parameters as well as qualitative parameters. In order to fit with thisproblematic, a methodological work has been realised at IPSN, in the context of the Becquerel nationalexercise, which has simulated a Borax type accident on an experimental reactor. The methodology consistsin making a systematic evaluation of indicators in order to provide intercomparating data for manyrehabilitation strategies. Thus, each strategy is evaluated on the one hand in terms of radiological benefit and on the other hand, in terms ofincidences such as duration of realisation, materials and human means, workers doses, amount of generatedwastes. In this context, calculations highlighted the importance of counter-measures aiming at reducingthe external exposure, which is the dominating exposure pathway. The counter-measures aimed at reducingthe dose by ingestion lead to a reduction of specific activity are then useful mainly in regard to thelimits of commercialisation. This work is a first and useful contribution to the clarification of thepost-accidental rehabilitation problem. It has also put the light on three important needs: formalisationof counter-measures and gathering into a data base, adaptation of calculation tools to make their useeasier, and improvement of the knowledge of the operational considerations for the interventions.

Effect of organic acids on 241 americium and 237 neptunium desorption from an acidic cultivated soil.Naturally occurring organic substances have been recognised as one important factor affecting the behaviour in the environment of transuranic actinides. This experimental study aims at evaluating if some naturally occurring carboxylic acids (vanillic, citric, lactic, oxalic) would affect 241Am or237Np availability in an acidic agricultural soil. Data show that these acids enhance the desorptionof americium and neptunium from the soil, with a noticeable effect of citric acid. The fraction desorbedis multiplied by more than 10 for 0.1 M citric acid, and by 3 or 4 with other acids, in relation withthe complexation of radionuclides with these acids. The desorption increases with molar concentration ofthe acids because of the decrease of pH in acidified soils, except for oxalic acid. The soil moistureconditions seem to affect the desorption results: the percentage desorbed is approximately 10 times lowerfor batch experiments (saturated conditions) than for centrifugation corresponding to unsaturated soilconditions. These preliminary data are mainly qualitative, but they show that it could be interesting totake into account more realistic physico-chemical conditions when measuring desorption ratios forcultivated soils.

Irradiation of unknown pregnancy: review of 17 cases.The article summarizes the analysis of 47 cases of pregnant women who did not know their pregnancy and had undergone one or more diagnostic radiological examinations. We distinguished two groups. The firstgroup G1 consisting of 12 women whose exposure to radiation had been focused under diaphragmatic regionand occurred during the critical period of organogenesis with a gonadal dose estimated to range 12 to 52mGy. A therapeutic abortion had been recommended to these women. The second group G2 consisting of 35women whose exposure to radiation interested directly or indirectly the above diaphragmatic region withdose lower than 10 mGy. To these women, a recommendation to continue their pregnancy had been given. Weinvestigated only 17 pregnant women issues; 7 from G1 et 10 from G2. We noted that there were nospontaneous abortion or major abnormalities or malignant diseases. However, 4 minor abnormalities wereidentified among the examined children sample: facial dysmorphism, anus atresia, hypospadias and harelip.These anomalies could not be attributed to the irradiation effects because the conceptus received verylow doses during the minimal risk gestation period. We believe that the malformations observed may beattributed to congenital malformation risk.

1999 occupational dosimetry in EDF's nuclear power plants: comments and analyse.The year 1999 ended with rather positive results concerning worker dosimetry, which is constantly decreasing. The targeted objective for the year 2000 (1.2 man.Sv per reactor) was already attained in 1999(1.17 man.Sv). However, even though the 1 300 MWe level still continues to progress, the 900 MWe level seems to marking time. In the case ofindividual dosimetry, even though it remained stable on the whole, nonetheless the number of workers themost strongly exposed decreased very much. These advancements should be considered as a part of theactions committed not only within the scope of optimization, but also in the reduction of shutdown periodsfor refueling, the extension of the fuel cycle (loading 1/4 of a core) and the revision of the maintenancepolicy (implementation of the optimization of reliability oriented maintenance). 1999 was the year whenthe initial effects of the "cleanliness"plan launched in 1998 were noted. This plan has already allowedimproving notably the situation in terms of contamination in the transport of spent fuel. However, theexposure incident which occurred at Tricastin, as well as other minor malfunctions, incite in us prudenceand more rigor in the performance of operations related to radiation protection.