Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where R. Gurriaran is active.

Publication


Featured researches published by R. Gurriaran.


Journal of Environmental Radioactivity | 2015

Spatial distributions of radionuclides deposited onto ground soil around the Fukushima Dai-ichi Nuclear Power Plant and their temporal change until December 2012.

Satoshi Mikami; Takeshi Maeyama; Yoshifumi Hoshide; Ryuichi Sakamoto; Shoji Sato; Naotoshi Okuda; Stéphanie Demongeot; R. Gurriaran; Yoshitomo Uwamino; Hiroaki Kato; Mamoru Fujiwara; Tetsuro Sato; Hiroshi Takemiya; Kimiaki Saito

Spatial distributions and temporal changes of radioactive fallout released by the Fukushima Dai-ichi Nuclear Power Plant accident have been investigated by two campaigns with three measurement schedules. The inventories (activities per unit area) of the radionuclides deposited onto ground soil were measured using portable gamma-ray spectrometers at nearly 1000 locations (at most) per measurement campaign. Distribution maps of the inventories of (134)Cs, (137)Cs, and (110m)Ag as of March, September, and December 2012 were constructed. No apparent temporal change of the radionuclide inventories was observed from March to December 2012. Weathering effects (e.g., horizontal mobility) were not noticeable during this period. Spatial dependence in the ratios of (134)Cs/(137)Cs and (110m)Ag/(137)Cs were observed in the Tohoku and Kanto regions. The detailed maps of (134)Cs and (137)Cs as of September 2012 and December 2012 were constructed using the relationship between the air dose rate and the inventory.


Environmental Science & Technology | 2011

Transfer of 131I from Fukushima to the vegetation and milk in France.

V. Parache; L. Pourcelot; S. Roussel-Debet; D. Orjollet; F. Leblanc; C. Soria; R. Gurriaran; Ph. Renaud; O. Masson

Iodine-131 and various other radionuclides were released into the atmosphere from the damaged Japanese reactors of Fukushima Dai-ichi from 12 to 22 March 2011. The contaminated air mass was detected in France after 24 March; samples of grass, vegetables, and milk have been analyzed for (131)I by the IRSN, considering the fact that few values of iodine-131 transfer parameters have been directly measured in situ, due to the radioactive decay of this isotope. Data are compared with calculated values according to the air iodine concentration. The apparent dry deposition velocity of iodine on grass is therefore estimated to range between 1 × 10(-3) and 5 × 10(-3) m s(-1) from site to site. In addition, the grass to milk transfer factors are 2.8 × 10(-2) and 3.6 × 10(-3) d L(-1) for goats and cows milk respectively. These parameters fit well with the current values usually considered for radioecological assessment.


Journal of Environmental Radioactivity | 2013

Fission product activity ratios measured at trace level over France during the Fukushima accident

A. de Vismes Ott; R. Gurriaran; X. Cagnat; Olivier Masson

The nuclear accident of Fukushima Dai-ichi (Japan) which occurred after the tsunami that impacted the northeast coasts of Japan on March 11th, 2011 led to significant releases of radionuclides into the atmosphere and resulted in the detection of those radionuclides at a global scale. In order to track airborne radionuclides from the damaged reactors and to survey their potential impact on the French territory, the French Institute of Radiation Protection and Nuclear Safety (Institut de Radioprotection et de Sureté Nucléaire IRSN) set up an enhanced surveillance system to give quick results as needed and later give quality trace level measurements. Radionuclides usually measured at trace levels such as (137)Cs and in a very sporadic way (131)I were reported. Radionuclides that we had never measured in air since the Chernobyl accident: (134)Cs, (136)Cs, the mother/daughter pairs (129m)Te-(129)Te and (132)Te-(132)I, and (140)La (from the mother-daughter pair (140)Ba- (140)La) were also reported. Except the (131)I/(137)Cs ratio, activity concentration ratios were constant. These ratios could be used to help source term assessment, or as data for transfer studies realized after the passage of contaminated air masses, typically using the (134)Cs/(137)Cs ratio.


Applied Radiation and Isotopes | 2016

Certified reference materials for radionuclides in Bikini Atoll sediment (IAEA-410) and Pacific Ocean sediment (IAEA-412).

M. K. Pham; P. van Beek; Fernando P. Carvalho; Elena Chamizo; D. Degering; C. Engeler; C. Gascó; R. Gurriaran; O. Hanley; A.V. Harms; Jürgen Herrmann; M. Hult; Yoshihiro Ikeuchi; C. Ilchmann; Günter Kanisch; G. Kis-Benedek; M. Kloster; M. Laubenstein; M. Llauradó; J.L. Mas; M. Nakano; Sven Poul Nielsen; I. Osvath; Pavel P. Povinec; U. Rieth; J. Schikowski; P. A. Smedley; Maria Suplińska; I. Sýkora; S. Tarjan

The preparation and characterization of certified reference materials (CRMs) for radionuclide content in sediments collected offshore of Bikini Atoll (IAEA-410) and in the open northwest Pacific Ocean (IAEA-412) are described and the results of the certification process are presented. The certified radionuclides include: (40)K, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (234)U, (238)U, (239)Pu, (239+240)Pu and (241)Am for IAEA-410 and (40)K, (137)Cs, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (235)U, (238)U, (239)Pu, (240)Pu and (239+240)Pu for IAEA-412. The CRMs can be used for quality assurance and quality control purposes in the analysis of radionuclides in sediments, for development and validation of analytical methods and for staff training.


Journal of Environmental Radioactivity | 2014

7Be, 210Pb and 137Cs concentrations in cloud water

L. Bourcier; Olivier Masson; P. Laj; Pascal Paulat; J. M. Pichon; P. Chausse; R. Gurriaran; K. Sellegri

Cloud water was sampled during 8 months, in 2008 and 2009, at the puy de Dome high-altitude atmospheric research station (France). The concentrations of (7)Be and (210)Pb, both naturally occurring radionuclides, and (137)Cs of anthropogenic origin, were determined. Those values are useful for a better knowledge of the aftermath cloud deposition and more generally for wet deposition assessment of radionuclides. This is of primary interest in case of a nuclear accident, especially considering (137)Cs deposition, both for high-altitude locations that are regularly embedded by clouds and also for lowlands where fog can occur. The (7)Be and (210)Pb average activity concentrations in cloud water found were 1.9±0.11 mBq m(-3) air and 140±10 μBq m(-3) air, respectively. For (137)Cs, the average concentration was 0.14±0.02 μBq m(-3) air. This very low-level is representative of the long term post-accidental background level. Indeed, for the studied period, the last accidental (137)Cs release was that of Chernobyl accident, in April 1986. To our knowledge this is the first data about (137)Cs reference level determination in cloud water. The comparison between cloud water and rain water concentrations showed a ratio cloud/rain ranging between 3.4 and 8.1, in agreement with previous studies performed on inorganic compounds. Scavenging efficiencies of aerosols by cloud droplets were also calculated with the additional aerosol concentrations routinely measured at the station and were quite low (0.13-0.40) compared to what has previously been observed for inorganic soluble ions.


Journal of Environmental Radioactivity | 2004

In situ metrology of 85Kr plumes released by the COGEMA La Hague nuclear reprocessing plant

R. Gurriaran; D Maro; P Bouisset; D Hebert; G Leclerc; D Mekhlouche; M Rozet; L. Solier

The IRSN (Institut de Radioprotection et de Sûreté Nucléaire, France) has started an in situ study of the behaviour of atmospheric releases close-by the COGEMA La Hague nuclear reprocessing plant. The study is designed to improve information on the dispersion of radioactive pollutants very close to the emission point--a 100 m height chimney. In this situation, close to the emission and height of the emission, Gaussian models generally used to predict the behaviour of atmospheric releases are not well adapted. The study is based on the characterisation of the 85Kr emitted during normal operations of the reprocessing process. Temporal and spatial variations of the plume shape were investigated with intensive in situ measurements. Live in situ techniques to measure the electrons and the photons emitted by the 85Kr have been implemented and will be described. Preliminary results showing the interest of the techniques were presented. Variations of the dose rates created by the photon flux of a plume were directly measured and correlated to other quantities.


Applied Radiation and Isotopes | 2017

Leda: A gamma-gamma coincidence spectrometer for the measurement of environment samples

H. Paradis; A. de Vismes Ott; X. Cagnat; F. Piquemal; R. Gurriaran

This paper presents a new gamma-gamma coincidence spectrometer to measure the radioactivity in environmental samples. This system, called Leda, is made of 2 HPGe and 1 NaI(Tl). The different analysis channels (single, in coincidence or in anti-coincidence) possible thanks to the digital electronics are described. Results obtained with environmental samples are shown. Despite its low efficiency, this method improves the detection limits for all emitters due to its very low background, and thus decreases the counting time.


Applied Radiation and Isotopes | 2016

Low level measurement of (60)Co by gamma ray spectrometry using γ-γ coincidence.

H. Paradis; A. de Vismes Ott; M. Luo; X. Cagnat; F. Piquemal; R. Gurriaran

This paper presents the latest development of the laboratory to measure the natural and artificial massic activities in environmental samples. The measurement method of coincident emitters by gamma-gamma coincidence using an anti-Compton device and its digital electronics is described. Results obtained with environmental samples are shown. Despite its low efficiency, this method decreases detection limits of (60)Co for certain samples compared to conventional gamma-ray spectrometry due to its very low background.


Journal of Environmental Radioactivity | 2018

Analysis of the relationship binding in situ gamma count rates and soil sample activities: Implication on radionuclide inventory and uncertainty estimates due to spatial variability

Huong Liên Nguyen; Chantal de Fouquet; Christelle Courbet; R. Gurriaran; V. Kashparov; Sviatoslav Levchuk; Evelyne Barker

The paper strives to identify through geostatistical simulations the parameters which build up a correlation between radionuclide activity concentrations measured on core samples and corresponding in situ total gamma count rates measured into boreholes drilled within the contaminated soil. This numerical exercise demonstrates that a linear relationship should exist between logarithmic values of in situ count rates and logarithmic values of activity concentrations when the contamination is strongly structured through space. A sensitivity analysis to some parameters (geostatistical range of the contamination structure, core sampling method, soil water content, multiple gamma-emitter contamination, etc.) is undertaken to identify which situations may impede the use of such a correlation. Then this approach is applied on Chernobyl measurements undertaken in 2015 and compared to the co-kriging method which considers the localization of the measurements and the additional measurements. It appears that co-kriging is a better estimator than linear regression, but the latter remains an acceptable way of estimating activity from gamma emitters and presents better results than lognormal regression. Therefore, total gamma logging measurements performed into boreholes of porous media contaminated by gamma-emitting radionuclides can be used for characterizing contamination and dealing with its spatial variability with the use of co-kriging.


Atmospheric Environment | 2010

Impact of an exceptional Saharan dust outbreak in France: PM10 and artificial radionuclides concentrations in air and in dust deposit

Olivier Masson; Damien Piga; R. Gurriaran; Donato D’Amico

Collaboration


Dive into the R. Gurriaran's collaboration.

Top Co-Authors

Avatar

X. Cagnat

Institut de radioprotection et de sûreté nucléaire

View shared research outputs
Top Co-Authors

Avatar

Frédérique Eyrolle

Institut de radioprotection et de sûreté nucléaire

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Olivier Masson

Institut de radioprotection et de sûreté nucléaire

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

A. de Vismes Ott

Institut de radioprotection et de sûreté nucléaire

View shared research outputs
Top Co-Authors

Avatar

C. Cossonnet

Institut de radioprotection et de sûreté nucléaire

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Mireille Provansal

Centre national de la recherche scientifique

View shared research outputs
Researchain Logo
Decentralizing Knowledge