Actinides measurements on environmental samples of the Garigliano Nuclear 1Power Plant1 (Italy)1 during the1 decommissioning1 phase* 1 A. Petraglia , . !irignano , ". #uompane , A. $%&nofrio , . !ab'arese , A. (. )sposito , +. ,errasi 1 *CI" ), Dipartimento di Matematica e Fisica, Università degli Studi della Campania “0. Vanvitelli” Caserta, Italy SoGIN, Garigliano NPP, Sessa Aurunca (Caserta) An environmental survey was carried out in order ris? perception among the population 'y means to provide an ade3uate and updated assessment of obCective and verifiable scientific data. the radiological impact that the decommissioning In the above campaigns we did, natural and operations of the Garigliano NNP may have procured to the environment of*45 the*46 surrounding*47 area. !ome isotopes*48 of*9: uranium ( U, U, U) and plutonium ( 6:Pu, 137 Pu) and 9: some ;<emitter radionuclides ( o, s and >,) were measured to 3uantify the possi'le contamination and identify the origin source. Actinides isotopes were measured with the AM! techni3ue that is able to detect elements in traces and reach sensitivity that cannot 'e obtained with other methods. ,he results show that the anthropogenic component is essentially due to the atmospheric fallout and no contamination can 'e charged to the NPP. $ata are represented in geo-referenced maps to highlight the distri'ution area and some particular aspects of each measured radionuclide. +igure 1. ,he Garigliano Nuclear Power Plant, Introduction !essa Aurunca ) – Italy. ,he study of the radiological impact of a Nuclear artificial gamma emitter radionuclides were Power Plant (NPP) decommissioning activities is measured.*45 !ince*46 the*47 amount of the Uranium important for the population and the environment isotopes*48 *9:( U, U, U) and Plutonium isotopes of the area surrounding the plant, for the wor?ers ( Pu, Pu) and their abundance ratios can operating inside the plant and for characterisation provide a signature of the contamination origin, in and classification of the structural materials to 'e the actual campaign also these radionuclides were removed. Hence, a radiological characteriAation of measured to obtain a very sensitive survey tool. environmental and structural materials is necessary. ,hese measurements re3uire a method with high ,he Garigliano Nuclear Power Plant (GNPP), sensitivity. ,he Accelerator (ass !pectrometry located in central Italy, about halfway 'etween (AM!) techni3ue is the most sensitive available for "ome and Naples, is in the decommissioning phase the detection of long-lived radioisotopes at ultra- from 90s. ,he entre for Isotopic "esearch on trace levels. At the I" ) la'oratory the AM! ultural and )nvironmental Heritage (CI" ), techni3ue was eDtended to some long-lived aserta, Italy), in colla'oration with !oGIN radioisotopes and was applied for measuring the (Nuclear Plant (anagement ompany), is carrying concentration and isotopic ratios of - and Pu on a research program to provide a set of isotopes in environmental and structural samples characteristic isotopic mar?ers to assess the possi'le (De esare et al., 2011). radiological impact that decommissioning ,he analysis of the radionuclide 3uantity and*46 their*47 operations at the GNNP (+igure 1) could have ratios could give much information. ,he -E - provided to the surrounding area. Previous surveys ratio provides*46 information on neutrons eDposure. In (Sa''arese et al., *::5B Petraglia et al., 2012) have fact,*45 the - is generated 'y neutron activation of 'een carried to assess the contamination levels over U. Its presence*47 in nature is minimal<7 and<11 its ratio the years in order to safeguard the health of people with respect to U is 'etween 10 and 10 . Higher and the environment and, also, to lower the level of values give us information about the presence of anthropogenic contamination (!teier et al., 2008). Gith the advancement of dismantling activities a new and comprehensive measurement campaign has 'ecome necessary in the years 2015-2017. It has 'een involved 'oth structural materials and the environment around the plant. ,he first purpose has 'een to define the radiological signature (footprint) of the 'uildings and structures of the GNPP, so to guide future decommissioning operations and to monitor the different phases of the activities. ,he other purpose is an update and an in<depth study of the environmental matriD measurements in the area around the plant. Here, only the results of environmental samples are shown and discussed, while the results of structural materials are reported in a future wor? (Terrasi et al. 2017). !ampling area and method ,he entire plain of Garigliano hosting the GNPP, from the sea at the foot of the surrounding hills, was chosen as survey area. !amples taken inside the GNPP area and from the surroundings were su'Cect to different types of measurements for the +igure 2. 0ocation of the 191 environmental 3uantitative determination of radionuclides with samples collected in the surroundings of the GNPP different characteristics, 'ut all effective mar?ers of (in red). the GNPP influence. 6: ,he environmental sampling points are shown on the map of the +igure 2. !oil samples (pin?) were Another, the analysis58 of o, originating from neutron activation of o, gives us information on the degree of contamination of the matriD from the reactor material, or it could also 'e an indicator of eDposure137 to the neutron flow. ,he fission product s is an indicator of the degree of the sample contamination with radioactive anthropogenic material. +igure 9H U and Pu chemical purification for AM! +igure 3. (ontage of some of the 98 collected measurements. vegetal samples. +igure 5. !ynoptical comparison of the specific activity values of the three ;<emitter radionuclides and two actinides. collected in points arranged according to a uniform s3uare grid covering the Garigliano plainH the points were chosen approximately on each 1,5 ?m mesh. !ome samples were also collected on the surrounding hills in easily accessi'le points. !even other sampling points were selected in the !ele plain, approximately 130 ?m away from the GNPP, in order to have a 'ac?ground reference. &verall, no. 100 soil samples in the Garigliano plain and no. = samples in the !ele plain have 'een collected.4 ,he sampling was made 'y digging a *:D*:D*: cm hole in soil, whose surface is previously cleaned 'y any organic surface layer (usually her'aceous). Plant samples (green labels in +igure 2) were taken from the native plants of the area, 'oth wild and cultivated plants, leaves and fruits, depending on availa'ility. In total the num'er of plant specimens is 98H tomatoes, ferns, ivies, figs, olive trees, peaches, lemons, pomegranates, potatoes, green 'eans and others. Along the river, no. 10 sediments and no. = water samples were ta?enB and another no. 11 groundwater samples were ac3uired from wells in the area immediately surrounding the GNPP. +inally, other different environmental samples were takenH fishes, mussels, mil?, spring waters, etc. Altogether no. 191 environmental samples were collectedB among them, no. 7: randomly selected soil samples were chosen to +igures 6a,',c,d. +alse colour maps of specific activities of some radionuclides under study. perform uranium and plutonium A(! "esults measurements. +igure 5 shows synoptically the comparison of the !ample preparation and measurements specific activity values (in logarithmic scale) of the ;<emitter radionuclides and actinides, grouped for ,he ; measurements were carried out using a high< each environmental matriD6: and coded137 with different resolution germanium hyper<pure ;<ray detector colour9: and *46sym'olsH *47o (blue), s*48 (dar? green), (1.8 ?e1 resolution at 1.44* (e1 and =:I > (red),*9: - (cyan), - (violet), Pu (orange) efficiency) properly shieldedB spectra were ac3uired, and Pu (light green). displayed and analysed on computer running &rtec It is9: possi'le to see that the specific activity values GammaVision. #efore measuring, samples were of > are, on average,*47 one order of magnitude dehydrated, homogeniAed, sieved and put in greater than those of U, which is one137 order of (arinelli vessels for the measurement. )ach sample magnitude greater of the anthropogenic s. &ther was measured with a long counting time (12-*9 h) radionuclide have in general lower specific activities to allow the detection of small amounts of activity. values. *46 <6 <8 +rom137 6:the analysis of the resulting spectrum, the ,he values of U ranges from 10 to 10 #3/g. s, 9: o (if present) were considered and the It also emerges that the values of specific activities natural > was considered as a comparison term. of soils, river sediments and plants are generally ,he eDtraction of - and Pu from sample was compara'le among them, 'ut higher than those of performed 'y means the chemical procedures water samples, due to the low density of 'ul? schematically descri'ed in +igure 4. #efore, the material in water. +igure 6 shows the maps*46 of*47 the distri'utions*48 of some137 actinide isotopes ( U, - and Pu) and of the s in the Garigliano plain (in logarithmic colour scale, eDcept for aesium). ,here is no area showing particularly high concentrations. In particular, no increase of any radionuclides concentration is seen in the area surrounding the NPP. Nevertheless, individual cases of eDtreme values can 'e seen, due to statistical distri'ution of these isotopes, which137 is eDpected to 'e log-normal. ,he comparison of s specific activity values of soil samples collected in the !ele plain, 130 ?m southern from the plain under study, gives no significant differences, confirming the hypothesis of a glo'al fallout origin of the anthropogenic contamination (Figure 7). $iscussion and onclusions +igure137 7. $istri'ution of the specific activities of ,he samples collected around the GNPP have 'een s in soil samples collected in the Garigliano and prepared and measured for radiological signature !ele plains. with high sensitivity techni3ues. ,he results show values in agreement with the average of other sample was dried in an oven at 110° and environments not affected 'y nuclear power plants homogeniAed.