This article proposes an assessment of the ingestion doses potentially received by peopleliving in the Japanese areas most severely affected by the radioactive deposits due to theFukushima nuclear accident. The assessment distinguishes two consecutive periods: thefirst 2 months (March 15th to May 15th 2011) and the rest of the year 2011, according tothe two main foodstuff contamination periods identified (Renaud et al.,2013). On the basis of the worst-case hypothesis that can reasonably be made, theestimated doses are much lower than they might have been in other circumstances, onaccount of generally moderate levels of contamination for most foods, early evacuation ofthe most severely affected areas and the consumption bans ordered by the Japaneseauthorities. Thus, a single ingestion of 100 g of leafy vegetables in the early days by aone-year-old child living in non-evacuated localities near Iitate and Kawamata could haveled to an equivalent dose to the thyroid of about 25 mSv; and to a thyroid dose of about140 mSv for the rather unrealistic scenario of a daily consumption. Because of the rapiddecrease in the contamination of vegetables and a much weaker contamination of othercrops, and thanks to measures taken by the authorities (prohibition of consumption, use ofcertain fodder, etc.), the ingestion doses potentially received during the remainder ofthe year 2011 are estimated to be below 1 mSv. In the event that sales limits would havebeen ignored, only repeated consumption of mushrooms would have led to doses above thatlevel. Even with the worst-case hypotheses, the doses potentially caused by ingestion aremuch lower than those resulting from outdoor exposure to radioactive deposits:approximately several millisieverts in a year for the population living in thenon-evacuated localities near Iitate and Kawamata.

During and after the Fukushima accident, the IRSN collected and interpreted the resultsof radiological measurements performed on foodstuffs of terrestrial origin published byJapan's Ministry of Health between mid-March 2011 and July 2012. Analysis of the findingsshows that the accident's date, livestock-rearing practices and the deposits'characteristics had a decisive influence. The fact that radioactive fallout occurred veryearly in the growing and breeding season largely explains the moderate contamination ofmost foodstuffs of terrestrial origin, notably in the areas with the largest deposits. Inthe case of dairy products and meat, feeding imported fodder to livestock in stables, acommon practice in Japan, compounded the calendar effect. Measurements published in Japanhave also borne out the particular sensitivity of mushrooms, including cultivated species,and game.

In 2011 the IRSN conducted several assessments of atmosphericradioactive releases due to the Fukushima Daiichi NPP accident (March11, 2011) and of their impact on Japan’s terrestrial environment.They were based on the IRSN’s emergency management tools and onthe abundant information and technical data gradually publishedin Japan. According to these assessments, the main release phaselasted from March 12 to 25, 2011 and impacted Japanese land in twoevents, the first on 15 and 16 March, in which the main radioactivedeposits were formed, and the second from March 20 to 23, whichwas less significant. The highest amounts of radioactive deposits werefound in an area extending upwards of several tens of kilometersnorthwest of the plant. Lower amounts were discontinuously scatteredin an area extending up to over 250 km away. Initially composedmainly of short-lived radionuclides, the deposits’ activity sharplydecreased in the subsequent weeks. Since the summer of 2011, cesium-134and cesium-137 have become the residual deposits’ main components.According to IRSN estimates, in the absence of protection, the dosesdue to exposure to the radioactive plume during the atmosphericrelease phase may have been potentially higher for people who remainedin coastal areas up to several tens of kilometers north and southof the damaged plant. Thereafter, people living up to 50 km northwestof the plant, outside the 20-km emergency evacuation zone, were potentiallymost vulnerable to residual radioactive deposits over time.

The French Decree of 25 May 2005 [4] relative to activities using naturally occurring radioactive materials (NORM) not used because of their radioactive properties imposes that the operators assess effective doses received by workers and populations. To date, about sixty studies have been submitted to the French public authorities. Within this context, the French public authorities asked IRSN to develop a tool for evaluating the quality and the comprehensiveness of these studies and for identifying industrial plants with radiological protection problems. This tool is aimed at helping the regional representatives of French public authorities in their duty to analyse these studies. The aim of this presentation is to illustrate the application of the tool developed by IRSN and to present the French feedback.

From the beginning of 2002, Troyes prefecture has initiated a study about the management of a nuclear crisis caused by an accident at the Nogent-sur-Seine nuclear power plant. Several working groups were created, notably the `Decontamination of soil and food chain' group. The first results of this group, which involves the District Agricultural and Forestry Department, the Farming Chamber, the Institute for Radiological Protection and Nuclear Safety and the Veterinary Division are presented here. The scenario that had been developed for the accident considers the release of 3 radionuclides (131I, 134Cs and 137Cs) in the environment. The scale of the crisis didn't require the evacuation and the sheltering of the population during the emergency phase. The consequences on the local agricultural products (cereal, sugar beet, vine, milk, cow meat ...) have been assessed up to 50 km and different strategies of agricultural countermeasures have been studied regarding to the local constraints (soil types, surfaces and quantities concerned) and to the consequences of their implementation (waste types and quantities, costs). Then, decision-making diagrams summed up the technical results and allowed to deepen the global thought.


This paper is intended to present the experience feedback of the IRSN's involvement in the reflection on the management of a nuclear crisis. It sums up some results of the French FARMING working group, corresponding to the mobilization of a wide range of Agricultural Technical Institutes and to the appraisal of a compendium of agricultural countermeasures for the rehabilitation of rural contaminated territories in post accidental situations. Indeed, in France, since a few years, this problem has been almost exclusively considered by radiation protection experts, with no involvement of the other concerned actors. But according to the weight of the agro industrial sector in this country and to the problems related to the management of contaminated food in post accidental situations, the cooperation between radiation protection experts and agro industrial stakeholders appeared more and more necessary. Indeed, above all, farmers and other local actors would take a significant part to the rehabilitation actions from the short term to long term of a nuclear crisis period and then share the responsibilities of the crisis management. The working group has therefore opened new debates at the national level and valuable results have been obtained from the meetings at technical and strategic levels.

Radiological impact assessment of very low-level radioactive waste management pathways.Two approaches are currently being adopted for the management of very low-level waste (VLLW): disposal insurface facilities and, for some categories of VLL waste, the implementation of treatment and utilisationchannels. In this paper, the orders of magnitude of the radiological consequences which may result fromthese two options are discussed, in a matter of a description rather than a comparison. As regards disposal, radiological impact is presented through a generic case, along with the uncertainties stemmingfrom the variability of the parameters associated with its design, as well as those associated with thegeosphere and the biosphere. In the case of treatment and utilisation channels, such as disposal orrecycling of VLL waste oils or VLL wastes containing asbestos, the assessment of radiological consequencesdeals with the public exposure and with the occupational exposure on the basis of a stage-by-stagebreakdown of the industrial process.

>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.