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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  • This article was downloaded by: [Eindhoven Technical University]On: 22 November 2014, At: 12:22Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: MortimerHouse, 37-41 Mortimer Street, London W1T 3JH, UK

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    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 & 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.

    To cite this article: Takeshi Tsukada, Koichi Uozumi, Takatoshi Hijikata, Tadafumi Koyama, Keiji Ishikawa, Shoichi Ono,Shunichi Suzuki, Mark S. Denton, Rich Keenan & 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

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  • Journal of Nuclear Science and Technology, 2014Vol. 51, Nos. 78, 886893, http://dx.doi.org/10.1080/00223131.2014.921582

    ARTICLE

    Early construction and operation of the highly contaminated water treatment system in FukushimaDaiichi Nuclear Power Station (I) ion exchange properties of KURION herschelite

    in simulating contaminated water

    Takeshi Tsukadaa, Koichi Uozumia, Takatoshi Hijikataa, Tadafumi Koyamaa, Keiji Ishikawab, Shoichi Onob,Shunichi Suzukib, Mark S. Dentonc, Rich Keenanc and Gaetan Bonhommec

    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,

    2020 Main Street, Suite 300, Irvine, CA, USA

    (Received 10 January 2014; accepted final version for publication 23 April 2014)

    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.

    Keywords: herschlite; ion exchange; adsorption; Langmuir-type equation; Cs; contaminated water; FukushimaDaiichi Nuclear Power Station

    1. Introduction

    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.

    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

    Corresponding author. Email: tsukada@criepi.denken.or.jp

    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.

    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.

    C 2014 Atomic Energy Society of Japan. All rights reserved.

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    http://dx.doi.org/10.1080/00223131.2014.921582mailto:tsukada@criepi.denken.or.jp

  • Journal of Nuclear Science and Technology, Volume 51, Nos. 78, JulyAugust 2014 887

    Figure 1. Diagram of water treatment system for highly con-taminated water accumulated in Fukushima Daiichi NPS.

    Fundamental data on the herschelite-type zeolite,whichwas applied using theKURIONdecontaminationsystem, were indispensable for estimating the system de-sign proposed by KURION.

    2. Overview of the contaminated water treatmentsystem in Fukushima Daiichi Nuclear PowerStation

    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].

    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,

    Figure 2. Schematic of Cs adsorption instrument inFukushima Daiichi NPS.

    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.

    3. Experimental

    3.1. MaterialsAll kinds of media applied to the Cs absorption in-

    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.

    3.2. SolutionThe radioactivities of Cs-134 and Cs-137 in the con-

    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.

    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.

    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.

    Additionally, no information was available on thetype or amount of oil in the contaminated water. There-fore, some solutions were prepared by gradually mixing

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  • 888 T. Tsukada et al.

    water with commercial turbine oil (FBK turbine oil, JXNipponOil &EnergyCorporation) or heavy oil (MarineT103, JX Nippon Oil & 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.

    3.3. Adsorption test methodThe procedure for the batch-type adsorption test was

    as follows:

    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.

    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.

    After mixing, the sample solution was separatedfrom herschelite using a filter of 0.45mpore size.

    The Cs concentration in the solution was mea-sured using an atomic absorption spectrometer(Thermo Fisher Scientific, S4).

    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.

    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.

    4. Results

    4.1. Cs adsorption properties of each herschelitein pure water and seawater

    The Cs loading (Q) in hershelite was calculated fromthe Cs concentrations of the solution before and aftercontact with hershelite using the following equation:

    Q = (C0 C1) V/M(mmol/g), (1)

    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).

    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.

    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,

    Figure 3. Cs loading as function of equilibrium Cs concen-tration for KURION herschelite in pure water.

    Figure 4. Cs loading as function of equilibrium Cs concen-tration for KURION herschelite in seawater (3.4 wt% salt).

    respectively.

    Kd = Q/C1 (ml/g). (2)

    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

    Figure 5. Distribution coefficient (Kd) for Cs as function ofequilibriumCs concentration forKURIONherschelite in purewater.

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  • Journal of Nuclear Science and Technology, Volume 51, Nos. 78, JulyAugust 2014 889

    Figure 6. Distribution coefficient (Kd) for Cs as function ofequilibrium Cs concentration for KURION herschelite in sea-water (3.4 wt% salt).

    difference further widens with decreasing equilibriumconcentration. Although the Cs loadings are in theorder of H > SMZ > AGH in pure water, H and AGHcan load almost the same amount of Cs in the seawater.Additionally, the difference between H and SMZ wassmaller in the seawater.

    The KURION decontamination system was de-signed such that almost all Cs in the contaminated wateris removed by H. The obtained Kd values of H in purewater were varied from 6.2 103 to 6.7 104 at eachequilibrium concentration from 2.4 107 to 1.2 104mmol/ml, as shown in Figure 5. On the other hand,the reported Kd values of IE-96 zeolite are varied from7.6 103 to 4.6 104 at each equilibrium concentrationfrom 1.2 1010 to 5.2 105 mmol/ml [10]. IE-96 ze-olite was adopted in Cs removal in the contaminatedwater treatment facility in TMI. Therefore, it was con-firmed thatKURIONHherschelite has almost the sameperformance in pure water as IE-96 zeolite.

    The fundamental performance of the process pro-posed by KURION had to be evaluated in Japan atan early stage in the facility design consideration. Inparticular, our major concern was determining theamount of zeolite necessary and the number of spentzeolite columns that would be generated. From theviewpoint of facility operation, the radiation dose fromzeolite columns has to be evaluated in order to protectthe operators.

    As mentioned above, the Cs concentration in thecontaminated water is estimated to be 12 ppm (7.5 106 to 1.5 105 mmol/ml). Figure 4 shows that 1 g ofH herschelite can load 1.0 103 to 1.0 102 mmolof Cs in equilibrium with the contaminated water. Her-schelite near the inlet of the solution in the column isalways in contact with the contaminated water contain-ing sea salt. Thus, themaximum total Cs loading per onecolumn is estimated from above the Cs loading per 1 gof zeolite and the amount of the zeolite in the column.Using the evaluated maximum Cs loading, tentative es-timations of the amount of herschelite necessary or thenumber of generated spent columns were made.

    Figure 7. Cs loading as function of equilibrium Cs concen-tration for H herschelite in several sea salt containing solution.(Dashed lines: Results of calculation using Langmuir equationfor each sea salt content).

    To confirm the safety aspect of the KURION sys-tem, we also evaluated the total radiation dose or heatgeneration rate by a simplified method when the Cs con-centration in the column is equal to the maximal Csloading.

    4.2. Effect of sea salt contents on adsorptionThe Cs loadings of H herschelite in the solutions

    with various sea salt contents are shown in Figure 7. Thedata in pure water (0.0 wt%) and seawater (3.4 wt%) aresame as those of H herschelite in Figures 3 and 4, re-spectively. The sea salt dissolved in the solution has anegative effect on the Cs loading if the concentration ofthe sea salt is relatively high. Since there is little differ-ence between the Cs loadings in the pure water (0.0 wt%)and seawater (0.034 wt%), the effects of sea salt can beignored if the seawater is diluted 100-fold.

    The ion exchange capacity, which corresponds to themaximum loading in Figure 7, is estimated to be about2.0 mmol/g for H herschelite at an equilibrium Cs con-centration higher than 1.0 102 mmol/ml, regardlessof the sea salt content. Compared with the Na concen-tration of 0.47 mmol/ml in the 3.4 wt% sea salt solu-tion, the Cs ion exchange capacity of H herschelite is notaffected by Na ions of a 50 times higher concentrationthan the Cs ions.

    The ion exchange capacity of H herschelite is almostthe same as that of IE-96, which is 2.02.5 meq/g (in theCs case, meq = mmol) in the commercial catalog [11].

    From Figure 4, it was assumed that the sea salt con-tent would have the same effect on the Cs loadings ofAGH and H herschelite. As for SMZ, the adsorptionperformance in the seawater was not examined in detail,because SMZ was replaced with Si sand immediately af-ter the start of the full-scale operation [12].

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  • 890 T. Tsukada et al.

    Figure 8. Effect of dissolved oil on Cs adsorption behaviorof H herschelite.

    4.3. Effect of oil content on adsorption behaviorThe effects of the amount of oil dissolved in the so-

    lution on the Cs loading of H herschelite are shown inFigure 8 with comparison of the data obtained for thenormal pure water and seawater. At a low Cs concen-tration in pure water, the oil content in the solution af-fects the Cs loading to some degree. However, it wasconcluded that the oil content has little impact on the Csadsorption behavior of H herschelite both in pure waterand seawater.

    The amounts of oil dissolved in pure water and sea-water were measured by the Japanese Industrial Stan-dards (JIS) method, in which the oil in the solution isextracted into carbon tetrachloride and the amount ofextracted oil is analyzed. The amount of oil in carbontetrachloride wasmeasured by infrared absorption spec-troscopy (Thermo Fisher Scientific, Nicolet iS FT-IR).

    Regardless of the volume ratio of the aqueous solu-tion to the oil phase, 10200 ppm turbine oil was foundto dissolve in pure water and seawater after a 3-day con-tact with turbine oil, and a similar amount of oil isexpected to dissolve in the actual contaminated water.Therefore, if suspended oil particles are removed usingfiltration or an SMZ (or silica sand) column, the remain-ing oil in the contaminated water has little effect on theCs adsorption performance on H herschelite.

    4.4. Cs adsorption properties of KHKH is prepared by precipitating KCCF within pores

    or on surface of H herschelite in order to enhance its Csadsorption [8]. The results of Cs loading for KH in thesolutions with various sea salt contents under batch typeadsorption conditions are shown in Figure 9. At an equi-librium concentration lower than 1.0 105 mmol/ml,more Cs can be loaded on KH than on H herschelite,which is shown in Figure 7.

    Figure 9. Cs loading as function of equilibrium Cs concen-tration for KH in several sea salt containing solutions.

    5. Discussion

    5.1. Adsorption isotherm equation for simulationcode

    Adsorption isotherm equations are essential in de-veloping a simulation code for the zeolite column, whichhas been developed aiming at evaluating the perfor-mance and predicting the operating conditions [13]. Sev-eral standard isotherm equations are already proposedfor the zeolite column applied to the radioactive solu-tion treatment [14]. We tried to make the adsorptionisotherm equation, which can be applied to a zeolite col-umn system designed byKURIONusing the present ad-sorption data.

    The contaminated water accumulated at FukushimaDaiichi NPS, initially contained sea salt at a relativelyhigh concentration, but this concentration decreasedgradually with the injection of pure water into the re-actor. In the simulation code, the change in the sea saltconcentration in the contaminated water must be moni-tored, and the effect of sea salt on the adsorption behav-ior must also be evaluated appropriately.

    Among well-known isotherm equations, the follow-ing Langmuir-type equation shown as Equation (3)was adopted, because the flat shape of the adsorp-tion isotherm at higher concentrations can be expressedeasily:

    Q = a1 C1/(1+ b1 C1), (3)

    where Q is the amount of Cs absorbed, a1 is the a coef-ficient, b1 is the b coefficient and Cl is the concentrationof Cs in solution.

    Using the data-sets of the Cs loading for different seasalt concentrations shown in Figure 7, individual Lang-muir equations for H herschelite were adopted for thesolutions containing 0.0 (pure water), 0.034, 0.34, 1.0,

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  • Journal of Nuclear Science and Technology, Volume 51, Nos. 78, JulyAugust 2014 891

    Table 1. Langmuir coefficients for H herschelite at varioussea salt concentrations.

    Langmuir coefficient

    Sea salt (wt%) a1 b1

    0.0 (5.6 0.3) 104 (3.0 0.1) 1040.034 (2.8 0.1) 104 (1.6 0.1) 1040.34 (4.0 0.2) 103 (2.0 0.1) 1031.0 (1.3 0.1) 103 (7.8 0.4) 1022.0 (7.8 0.4) 102 (4.6 0.2) 1023.4 (4.7 0.2) 102 (2.7 0.1) 102

    2.0 and 3.4 wt% of sea salt. The a1 and b1 coefficients ofthe Langmuir equation for each sea salt concentrationare estimated by regression analysis, and the estimatedvalues are listed in Table 1. The adsorption isothermsestimated using the Langmuir equations are shown inFigure 7 and compared with the adsorption data. At ar-bitrary sea salt concentrations between 0.0 and 3.4 wt%,

    Table 2. Langmuir coefficients of KCCF site in two-siteLangmuir equation for KH at each sea salt concentration.

    Langmuir coefficient

    Sea salt (wt%) a2 b2

    0.34 (6.9 0.3) 104 (3.4 0.2) 1061.0 (2.4 0.1) 104 (1.2 0.1) 1062.0 (1.5 0.1) 104 (7.4 0.4) 1053.4 (1.1 0.1) 104 (5.6 0.3) 105

    Note: a2/b2 = 0.02.

    the coefficients a1 and b1 in the Langmuir equation arecalculated by linear interpolation [13].

    5.2. Isotherm equation model of KHAt an equilibrium Cs concentration lower than

    1.0 105 mmol/ml, KH can load more Cs than H her-schelite, as described in Section 4.4, and the amounts

    Figure 10. Comparison between Cs loading data and adsorption isotherms estimated using two-site Langmuir equation for KH.

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  • 892 T. Tsukada et al.

    of Cs loading by H and KH are almost same at anequilibrium Cs concentration of more than 1.0 104mmol/ml.

    It is assumed that Cs ions may be exchanged at twodifferent kinds of ion-exchange site: the KCCF site andthe original site of H herschelite. It is also assumed thatthe ion exchange at the KCCF site may be predominantat lower equilibrium Cs concentration and that this siteis saturated at an equilibrium Cs concentration of morethan 1.0 105 mmol/ml.

    On this basis, the following two-site Langmuir equa-tion model is used for KH:

    Q = a1 C1/(1+ b1 C1)+ a2 C1/(1+ b2 C1).(4)

    The Langmuir coefficients a1 and b1 are assumedto be the same as those in Equation (3) derived fromthe H herschelite data. The coefficients a2 and b2 areestimated using only the KH data obtained at anequilibrium Cs concentration lower than 1.0 105mmol/ml. However, owing to the limit of Cs detectionby the atomic absorption spectrometer, only two orthree data-sets were obtained at an equilibrium Csconcentration below 1.0 105 mmol/ml. Here, it isassumed that the saturated Cs loading at the KCCFsite is 0.02 mmol/g at an equilibrium Cs concentrationabove 1.0 105 mmol/ml. With this assumption, therelation between a2 and b2 can be fixed, because thesaturated Cs loading corresponds to a2/b2 = 0.02 inthe Langmuir equation. Moreover, one more data-set,that is, the Cs loading of 0.02 mmol/g at an equilibriumCs concentration of 1.0 105 mmol/ml, can be intro-duced when the Langmuir equation coefficient a2 foreach sea salt concentration is estimated by regressionanalysis.

    The estimated a2 and b2 values for each sea saltconcentration are listed in Table 2. The adsorptionisotherms estimated using the first term of the two-siteLangmuir equation with only a1 and b1 and using thesecond term with only a2 and b2 are shown in Figure 10(a)(d), respectively, for each sea salt content. The sum-mation of all the Cs loadings obtained using the first andsecond terms of the two-site Langmuir equation showsgood agreement with the obtained data for KH.

    Therefore, it can be concluded that the two-siteLangmuir equationmodel is applicable to the estimationof the Cs adsorption behavior of KH.

    6. Conclusions

    KURION herschelite-type zeolite was adopted forCs removal in the radioactive waste water treatment fa-cility at Fukushima Daiichi NPS. The adsorption prop-erties of various kinds of KURION herschelite were ex-amined in Japan and used as basic data for the designdiscussion. Since the contaminated water contained sea-

    water and oils such as turbine oil, the effects of sea saltand dissolved oil content on Cs adsorption behaviorwere examined closely.

    The Cs loading of H herschelite in the seawater wasfound to decrease to nearly 1/10th of that in pure wa-ter. It was, however, concluded that KURION hersche-lite has sufficient adsorption capacity to remove Cs fromthe contaminated water by the proposed process. The ef-fect of dissolved oil could be ignored, because very littleamount of oil remains in the seawater. To develop a sim-ulation code that can analyze the adsorption behavioror predict the operation conditions of the actual decon-tamination system, necessary parameters and relationalexpression were also evaluated. Thus, Langmuir equa-tions that can be applied to the measurement of Cs ad-sorption isotherms in the sea salt containing water weredeveloped for H herschelite. Additionally, it was foundthat a two-site Langmuir equation can be applied to theanalysis of KCCF-added KH, because KCCF functionsas another ion-exchange site in addition to the normalsite of H herschelite.

    AcknowledgementsThe authors express their many thanks to Mr S. Sakuno,

    Mr R. Sagawa andMr N. Yahagi for their support in the anal-ysis.

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    [5] Uozumi K, IizukaM,Kinoshita K, Tsukada T, KoyamaT. Development of salt and metal waste treatmenttechnology for pyroprocess in CRIEPI (paper no.387026). Proceedings of GLOBAL 2011; 2011 Dec 1116; Makuhari, Chiba.

    [6] Tokyo Electric Power Company: Overview of decontam-ination instruments (adsorption tower)[Internet]. Tokyo:2011 June 17. Available from: http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts 110617 04-e.pdf

    [7] Tokyo Electric Power Company: Cesium decontamina-tion instrument diagram (Valve Status in H4 skid)[Internet]. Tokyo: 2011 June 23. Available from: http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts110623 01-e.pdf

    [8] Denton MS, Bostick WD. Development and testing oftwo novel and vitrification compatible classes of ionspecific media for application on the hanford waste

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  • Journal of Nuclear Science and Technology, Volume 51, Nos. 78, JulyAugust 2014 893

    treatment plant supplemental pretreatment and sec-ondary waste streams 11001. WM 2011 Conference;2011 Feb 27Mar 3; Phoenix, AZ.

    [9] Website of Tokyo Electric Power Company. http://www.tepco.co.jp/nu/fukushima-np/images/handouts 11042502-j.pdf. Japanese.

    [10] Brown GN, Carson KJ, DesChane JR, Elovich RJ. Per-formance evaluation of 24 ion exchange materials forremoving cesium and strontium from actual and sim-ulated N-reactor storage basin water. Richland (WA):Pacific Northwest National Laboratory; 1977. (PNNL-11711,UC-2030).

    [11] Product Information of INOVS IE-96 Ion Exchanger.UPO commercial catalog UOP Molecular Sieve SalesOffice (2/24/97).

    [12] Website of the Nuclear and Industrial Safety Agency atthe Ministry of Economy. Available from: http://www.meti.go.jp/earthquake/nuclear/pdf/20110816nisa2.pdf.Japanese.

    [13] Inagaki K, Hijikata T, Tsukada T, Koyama T, IshikawaK, Ono S, Suzuki S. Early construction and opera-tion of the highly contaminated water treatment sys-tem in Fukushima Daiichi nuclear power station (III) A unique simulation code to evaluate time-dependentCs adsorption/desorption behavior in column system. JNucl Sci Technol. 2014 (this issue).

    [14] Robinson SM, Kent TE, ArnoldWD, Parrott JR Jr. Thedevelopment of a zeolite system for upgrade of the pro-cess waste treatment plant. Oak Ridge (TN): Oak RidgeNational Laboratory; 1993. (ORNLM-12063).

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    Abstract1. Introduction2. Overview of the contaminated water treatment system in Fukushima Daiichi Nuclear Power Station3. Experimental3.1. Materials3.2. Solution3.3. Adsorption test method

    4. Results4.1. Cs adsorption properties of each herschelite in pure water and seawater4.2. Effect of sea salt contents on adsorption4.3. Effect of oil content on adsorption behavior4.4. Cs adsorption properties of KH

    5. Discussion5.1. Adsorption isotherm equation for simulation code5.2. Isotherm equation model of KH

    6. ConclusionsAcknowledgementsReferences

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