Early construction and operation of highly contaminated water treatment system in Fukushima Daiichi Nuclear Power Station (I) – Ion exchange properties of KURION herschelite in simulating contaminated water

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<ul><li><p>This article was downloaded by: [Eindhoven Technical University]On: 22 November 2014, At: 12:22Publisher: Taylor &amp; FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: MortimerHouse, 37-41 Mortimer Street, London W1T 3JH, UK</p><p>Journal of Nuclear Science and TechnologyPublication details, including instructions for authors and subscription information:http://www.tandfonline.com/loi/tnst20</p><p>Early construction and operation of highlycontaminated water treatment system in FukushimaDaiichi Nuclear Power Station (I) Ion exchangeproperties of KURION herschelite in simulatingcontaminated waterTakeshi Tsukadaa, Koichi Uozumia, Takatoshi Hijikataa, Tadafumi Koyamaa, KeijiIshikawab, Shoichi Onob, Shunichi Suzukib, Mark S. Dentonc, Rich Keenanc &amp; GatanBonhommeca Central Research Institute of Electric Power Industry, Nuclear Technology ResearchLaboratory, 2-11-1 Iwado-kita, Komae-shi, Tokyo 201-8511, Japanb Tokyo Electric Power Company, 1-1-3 Uchisaiwai-cho, Chiyoda-ku, Tokyo 100-8560,Japanc KURION, 2020 Main Street, Suite 300, Irvine, CA, USAPublished online: 19 Jun 2014.</p><p>To cite this article: Takeshi Tsukada, Koichi Uozumi, Takatoshi Hijikata, Tadafumi Koyama, Keiji Ishikawa, Shoichi Ono,Shunichi Suzuki, Mark S. Denton, Rich Keenan &amp; Gatan Bonhomme (2014) Early construction and operation of highlycontaminated water treatment system in Fukushima Daiichi Nuclear Power Station (I) Ion exchange properties ofKURION herschelite in simulating contaminated water, Journal of Nuclear Science and Technology, 51:7-8, 886-893, DOI:10.1080/00223131.2014.921582</p><p>To link to this article: http://dx.doi.org/10.1080/00223131.2014.921582</p><p>PLEASE SCROLL DOWN FOR ARTICLE</p><p>Taylor &amp; Francis makes every effort to ensure the accuracy of all the information (the Content) containedin the publications on our platform. However, Taylor &amp; Francis, our agents, and our licensors make norepresentations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose ofthe Content. Any opinions and views expressed in this publication are the opinions and views of the authors,and are not the views of or endorsed by Taylor &amp; Francis. The accuracy of the Content should not be reliedupon and should be independently verified with primary sources of information. Taylor and Francis shallnot be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and otherliabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to orarising out of the use of the Content.</p><p>This article may be used for research, teaching, and private study purposes. Any substantial or systematicreproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in anyform to anyone is expressly forbidden. Terms &amp; Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions</p><p>http://www.tandfonline.com/loi/tnst20http://www.tandfonline.com/action/showCitFormats?doi=10.1080/00223131.2014.921582http://dx.doi.org/10.1080/00223131.2014.921582http://www.tandfonline.com/page/terms-and-conditionshttp://www.tandfonline.com/page/terms-and-conditions</p></li><li><p>Journal of Nuclear Science and Technology, 2014Vol. 51, Nos. 78, 886893, http://dx.doi.org/10.1080/00223131.2014.921582</p><p>ARTICLE</p><p>Early construction and operation of the highly contaminated water treatment system in FukushimaDaiichi Nuclear Power Station (I) ion exchange properties of KURION herschelite</p><p>in simulating contaminated water</p><p>Takeshi Tsukadaa, Koichi Uozumia, Takatoshi Hijikataa, Tadafumi Koyamaa, Keiji Ishikawab, Shoichi Onob,Shunichi Suzukib, Mark S. Dentonc, Rich Keenanc and Gaetan Bonhommec</p><p>aCentral Research Institute of Electric Power Industry, Nuclear Technology Research Laboratory, 2-11-1 Iwado-kita, Komae-shi,Tokyo 201-8511, Japan; bTokyo Electric Power Company, 1-1-3 Uchisaiwai-cho, Chiyoda-ku, Tokyo 100-8560, Japan; cKURION,</p><p>2020 Main Street, Suite 300, Irvine, CA, USA</p><p>(Received 10 January 2014; accepted final version for publication 23 April 2014)</p><p>To support the design and operation of the decontamination system using KURION media for the treat-ment of highly contaminated water accumulated in Fukushima Daiichi Nuclear Power Station, CentralResearch Institute of Electric Power Industry has urgently carried out many kinds of research and devel-opment programs to support the operation of the decontamination system using columns filled with threekinds of KURION media (H, AGH and SMZ). Since the contaminated water at Fukushima Daiichi Nu-clear Power Station contained seawater and oil, the effects of sea salt and dissolved oil on Cs adsorptionbehavior were examined closely by batch type. The concentration of sea salt in the solutions was variedbetween 0.0 and 3.4 wt%. The Cs adsorption capacity of KURION herschelite in seawater decreased tonearly 1/10th of that in pure water, but it was still concluded that herschelite has sufficient adsorption ca-pacity to remove Cs from the contaminated water. The effect of dissolved oil could be ignored becauseof its low solubility in seawater. Langmuir-type adsorption isotherm equations, which can be applied forestimating Cs adsorption in sea salt containing water, were developed.</p><p>Keywords: herschlite; ion exchange; adsorption; Langmuir-type equation; Cs; contaminated water; FukushimaDaiichi Nuclear Power Station</p><p>1. Introduction</p><p>Since the accident at Fukushima Daiichi NuclearPower Station (NPS), the injection of cooling water intothe reactors has been continuous and a large amountof highly contaminated water leaked from the damagedreactors has been accumulated on the site. Radioactivematerials in the contaminated water should be separatedand the decontaminated water returned to the reactoras cooling water so that the accumulation of contami-nated water could beminimized and environmental con-tamination due to leakage of the contaminated waterprevented.</p><p>Among the radioactive elements in the contaminatedwater, Cs is one of the major sources of radiation emis-sion and, zeolite, which was used in the liquid wastetreatment after the Three Mile Island (TMI) Unit 2 ac-cident, is regarded as the best material for separating Csfrom the contaminated water by adsorption [1,2]. How-ever, the contaminatedwater at FukushimaDaiichi NPS</p><p>Corresponding author. Email: tsukada@criepi.denken.or.jp</p><p>contained a large amount of seawater because seawaterwas initially injected into the reactors as cooling wateras an emergency measure. Seawater also entered the tur-bine building as a result of tsunami, and heavy oil storedin tanks near the building as well as turbine oil also gotmixed with the contaminated water.</p><p>KURION herschelite-type zeolite was selected forthe radioactive wastewater treatment at FukushimaDaiichi NPS [3]. This zeolite was modified to exhibithigh Cs adsorption performance in highly concentratedNa solution; however, it was not known if herschelitewould work well in the seawater contaminated bythe oils. Therefore, in Japan, Tokyo Electric PowerCompany (TEPCO), Japan Atomic Energy Agency,Toshiba and Central Research Institute of ElectricPower Industry (CRIEPI) evaluated the performance ofKURION herschelite in the oil-contaminated seawaterusing several kinds of herschelite samples supplied byKURION.</p><p>C 2014 Atomic Energy Society of Japan. All rights reserved.</p><p>Dow</p><p>nloa</p><p>ded </p><p>by [</p><p>Ein</p><p>dhov</p><p>en T</p><p>echn</p><p>ical</p><p> Uni</p><p>vers</p><p>ity] </p><p>at 1</p><p>2:22</p><p> 22 </p><p>Nov</p><p>embe</p><p>r 20</p><p>14 </p><p>http://dx.doi.org/10.1080/00223131.2014.921582mailto:tsukada@criepi.denken.or.jp</p></li><li><p>Journal of Nuclear Science and Technology, Volume 51, Nos. 78, JulyAugust 2014 887</p><p>Figure 1. Diagram of water treatment system for highly con-taminated water accumulated in Fukushima Daiichi NPS.</p><p>Fundamental data on the herschelite-type zeolite,whichwas applied using theKURIONdecontaminationsystem, were indispensable for estimating the system de-sign proposed by KURION.</p><p>2. Overview of the contaminated water treatmentsystem in Fukushima Daiichi Nuclear PowerStation</p><p>The process flow diagram of the contaminated watertreatment system presented by TEPCO [4] is shown inFigure 1. As the water was contaminated with turbine oiland sea water, an oil separator and a desalination plantwere employed. A throughput as high as 1200 m3/dayof contaminated water was required depending on theamount of accumulated water and on the amount nec-essary to cool the damaged reactors. The system con-sisted of an oil separator installed by Toshiba, a cesiumadsorption device installed by KURION, a coagulat-ing sedimentation device installed by AREVA and a de-salination plant installed by Hitachi GE. CRIEPI wasasked to perform supporting research and developmenton theKURION adsorption system, in whichmost ofthe radioactive Cs was expected to be removed, becauseCRIEPI has extensive experience in developing zeolitecolumn systems for pyro-reprocessing, in which fissionproducts are removed from spent molten chloride saltused in electrorefining [5].</p><p>The system diagram of one unit of the Cs adsorptioninstrument is shown in Figure 2 [6]. The Cs adsorptioninstrument consisted of three skids, i.e., the surfactant-modified zeolite (SMZ) skid for removing oil and Te,</p><p>Figure 2. Schematic of Cs adsorption instrument inFukushima Daiichi NPS.</p><p>the H (herschelite) skid for removing Cs, and the silver-impregnated engineered herschelite (AGH) skid for re-moving I. TheH skid consisted of four columns, three ofwhich are in service and one is a spare containing freshmedia for the operation [7]. The Cs adsorption instru-ment consisted of four units operated in parallel. Sincea maximum throughput of 1200 m3/day was required,each unit should have a throughput of 12.5 m3/h.</p><p>3. Experimental</p><p>3.1. MaterialsAll kinds of media applied to the Cs absorption in-</p><p>struments were supplied by KURION, immediately af-ter the decision to adopt KURION system was made.Adsorption tests with SMZ, H and AGH produced byKURION [8] were carried out by CRIEPI. A surface-modified hereschlite (KH) by potassium hexacyanofer-rate (KCCF) was also used in the adsorption test.</p><p>3.2. SolutionThe radioactivities of Cs-134 and Cs-137 in the con-</p><p>taminated water sampled at the turbine building weresimilar at about 2.0 106 Bq/ml [9]. The total concen-tration of Cs in the contaminated water was calculatedto be about 1.0 wt. ppm on the basis of the specific ra-dioactivities of Cs-134 and Cs-137.</p><p>The initial Cs concentration in the solutions for thebatch-type adsorption test was determined so that thefinal Cs concentration in the solution in the equilibriumstate would remain in the range between 1.0 107 and1.0 101 mmol/ml. Then, the initial Cs concentrationwas set to be between 2 and 3000 ppm considering thesolution volume and the detection limit of Cs. As thesource of Cs, CsCl powder of 99.9% purity, purchasedfrom Wako Pure Chemical Industries, was dissolved ineach test solution.</p><p>Since there was initially no information on the seasalt concentration in the contaminated water, it was as-sumed that the contaminated water had a similar com-position to actual seawater in the most severe case. Inthe present study, instead of using actual seawater, sim-ulated seawater was prepared using commercial salt forsynthetic seawater named reef crystals (aquarium sys-tems). The composition of major elements (Na,Mg, Ca,K, Sr) in the synthetic seawater was found to be the sameas that of natural seawater in our ongoing another studyto estimate the effect of these elements on Cs adsorp-tion. The sea salt concentration in the solution was var-ied from 0.0 wt% (containing no sea water) to 3.4 wt%(corresponding to actual seawater) to evaluate the effectsof sea salt on the Cs adsorption properties of each her-schelite.</p><p>Additionally, no information was available on thetype or amount of oil in the contaminated water. There-fore, some solutions were prepared by gradually mixing</p><p>Dow</p><p>nloa</p><p>ded </p><p>by [</p><p>Ein</p><p>dhov</p><p>en T</p><p>echn</p><p>ical</p><p> Uni</p><p>vers</p><p>ity] </p><p>at 1</p><p>2:22</p><p> 22 </p><p>Nov</p><p>embe</p><p>r 20</p><p>14 </p></li><li><p>888 T. Tsukada et al.</p><p>water with commercial turbine oil (FBK turbine oil, JXNipponOil &amp;EnergyCorporation) or heavy oil (MarineT103, JX Nippon Oil &amp; Energy Corporation) in 200-mlglass bottles on a shaking table for 6 days. Then, appro-priate amount of CsCl was dissolved in the solutions foruse in the adsorption study.</p><p>3.3. Adsorption test methodThe procedure for the batch-type adsorption test was</p><p>as follows:</p><p> About 0.1 g of herschelite and 10 ml of eachsample solution were placed in a centrifugationtube, so that the solution volume/solid weight ra-tio (V/S) was 100 ml/g.</p><p> The tubes were fixed on a shaking table. Herschelite and a sample solution were mixed for72 h at about 60 cycles/min at room temperature.</p><p> After mixing, the sample solution was separatedfrom herschelite using a filter of 0.45mpore size.</p><p> The Cs concentration in the solution was mea-sured using an atomic absorption spectrometer(Thermo Fisher Scientific, S4).</p><p>The concentration of Cs in the analyzed solutionwasadjusted to be about 2.0 ppm and the atomic absorptionspectrometer can measure nearly 0.1 ppm. Thus eachdata might include 5% error.</p><p>Some adsorption tests were carried out for 14 days,and an equilibrium state was attained after 3 days (72 h).In some conditions, more than two test samples wereprepared and the replicate of the adsorption experimentswas confirmed from the obtained data.</p><p>4. Results</p><p>4.1. Cs adsorption properties of each herschelitein pure water and seawater</p><p>The Cs loading (Q) in hershelite was calculated fromthe Cs concentrations of the solution before and aftercontact with hershelite using the following equation:</p><p>Q = (C0 C1) V/M(mmol/g), (1)</p><p>whereC0 is the initial Cs concentration (mmol/ml) in theexperimental solution prior to contact, C1 is the equi-librium Cs concentration in the solution after contact(mmol/ml), V is the volume of solution (ml) and M isthe mass of herschelite (g).</p><p>The results of Q in each herschelite sample in theequilibrium state are shown in Figure 3 for pure waterand in Figure 4 for the seawater.</p><p>The distribution coefficient (Kd) is calculated fromthe Cs loading divided by the equilibrium Cs concentra-tion, as shown in Equation (2). The obtained Kd valuesare shown in Figures 5 and 6 for pure water and seawater,</p><p>Figure 3. Cs loading as function of equilibrium Cs concen-tration for KURION herschelite in pure water.</p><p>Figure 4. Cs loading as function of equilibrium Cs concen-tration for KURION herschelite in seawater (3.4 wt% salt).</p><p>respectively.</p><p>Kd = Q/C1 (ml/g). (2)</p><p>At an equilibrium concentration lower than 1.0 103 mmol/ml, the Cs loading of each herschelitesample is higher in pure water than in seawater, and the</p><p>Figure 5. Distribution coefficient (Kd) for Cs as function ofequilibriumCs concentration forKURIONherschelite in purewater.</p><p>Dow</p><p>nloa</p><p>ded </p><p>by [</p><p>Ein</p><p>dhov</p><p>en T</p><p>echn</p><p>ical</p><p> Uni</p><p>vers</p><p>ity] </p><p>at 1</p><p>2:22</p><p> 22 </p><p>Nov</p><p>embe</p><p>r 20</p><p>14 </p></li><li><p>Journal of Nuclear Science and Technology, Volume 51, Nos. 78, JulyAugust 2014 889</p><p>Figure 6. Distribution coefficient (Kd)...</p></li></ul>