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Fusion Engineering and Design 85 (2010) 1966–1969

Contents lists available at ScienceDirect

Fusion Engineering and Design

journa l homepage: www.e lsev ier .com/ locate / fusengdes

urrent status of design and engineering analysis of Indian LLCB TBM

aritosh Chaudhuri ∗, Chandan Danani, Vilas Chaudhari, R. Srinivasan,. Rajendra Kumar, S.P. Deshpande

nstitute for Plasma Research, Bhat, Gandhinagar 382428, Gujarat, India

r t i c l e i n f o

rticle history:vailable online 16 August 2010

eywords:EMO

a b s t r a c t

One of the key missions of the international thermonuclear experimental reactor (ITER) is to test andvalidate the various design concepts of tritium breeding blankets relevant to a power-producing reactorlike DEMO. India has developed two breeding blanket concepts such as, lead lithium cooled ceramicbreeder (LLCB) and helium cooled ceramic breeder (HCCB) for its DEMO. LLCB concept will be tested in

TERreeding blanketLCBhermal-hydraulics

ITER where Li2TiO3 ceramic breeder (CB) in the form of packed pebble beds is used as a tritium breedingmaterial and PbLi eutectic is used as multiplier, breeder, and coolant for the CB zones. A detail engineeringdesign and analysis has been executed for the LLCB TBM to optimize the flow parameters for helium andPbLi circuits, to estimate the temperature distribution in the various breeding zones and to ensure thethermal design limits for structural material and temperature window in ceramic breeder for effectivetritium extraction. The detailed thermo-hydraulic CFD using Fluent and FE simulation studies will also

r.

be discussed in this pape

. Introduction

India has proposed lead–lithium cooled ceramic breeder (LLCB)lanket concept for its DEMO, considering its forte in liquid metalechnologies and strong experience in diverse scientific areas rel-vant to blanket development. The LLCB TBM will be tested fromay 1 operation of ITER in one-half of a designated ITER port. LLCBlanket concept is distinct from other concepts as it inherits the fea-ures of both solid and liquid type concepts [1]. It consists of lithiumitanate as ceramic breeder (CB) material in the form of packed peb-le beds and PbLi eutectic as multiplier, breeder, and coolant for theB zones. Reduced activation ferritic martensitic steel (RAFMS) issed as the structural material for first wall (FW) which is activelyooled by helium (He) gas. The high pressure helium (He) coolingircuit is used for active cooling of FW structure. The tritium pro-uced in the ceramic breeder zones is extracted by low-pressureurge helium circuit at 1.2 bar + 0.1% of hydrogen to enhance the

sotope exchange of H and T. The tritium produced in the PbLi circuits extracted separately by an external system.

2-D thermal-hydraulic simulation studies using ANSYS has been

erformed based on the heat load obtained from neutronics cal-ulations to confirm heat removal and structural integrity underarious ITER heat load conditions [2,3]. In this study also the conju-ate heat transfer analysis using Fluent code along with the PbLi and

∗ Corresponding author. Tel.: +91 79 23962184; fax: +91 79 23962277.E-mail address: paritosh@ipr.res.in (Paritosh Chaudhuri).

920-3796/$ – see front matter © 2010 Elsevier B.V. All rights reserved.oi:10.1016/j.fusengdes.2010.07.003

© 2010 Elsevier B.V. All rights reserved.

CB zones has been performed to evaluate and optimize the coolantflow requirement for LLCB TBM. Conceptual design of the ancillarysystems, such as helium cooling system (HCS), tritium extractionsystem (TES) and coolant purification system (CPS), etc. is underprogress. The conjugate heat transfer model using Fluent code forcombined analysis of FW along with the PbLi and CB zones hasbeen considered. The details of the performance analysis and cur-rent status of design and engineering analysis of LLCB TBM will bepresented in this paper.

2. LLCB TBM design

The overall dimensions of the LLCB TBM are 1.66 m (pol) ×0.484 m (tor) × 0.534 m (rad). Fig. 1 shows the different compo-nents of LLCB TBM includes the FW, top, bottom, and back plateand the ceramic breeder assembly inside the module. PbLi eutecticis flowing around all CB zones extracts heat from them as well asthe heat generated within it as shown in Fig. 2. This figure shows thedetails of all five CB zones and the path of six PbLi channels aroundthese CB zones. The PbLi flow velocity is moderate enough suchthat its self generated heat and the heat transferred from ceramicbreeder bed is extracted effectively. Effectively there is no separatehelium cooling in the interface RAFMS plates between the PbLi and

ceramic breeder.

The FW is designed to withstand the energetic particle fluxesand heat fluxes from the plasma, high thermal and mechani-cal stresses and magnetic forces during plasma disruptions. TheFW of TBM is coated with 2 mm beryllium as the plasma facing

Paritosh Chaudhuri et al. / Fusion Engineering and Design 85 (2010) 1966–1969 1967

Fig. 1. Different components of LLCB TBM module.

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Fig. 2. Schematic of

aterial on the plasma facing side of the FW structure. The FWtructure is actively cooled by helium gas flowing through theooling channels which are running in radial–toroidal–radial direc-ion and designed to withstand the He pressure of 8 MPa. The heatransfer coefficients (HTC) obtained form the correlations revealedhat required cooling could be achieved by artificially rough-ned surface towards the plasma side wall of He cooling channelhich helps to keep the RAFMS temperatures below the allowable

imit.

. Performance analysis

.1. Neutronic analysis

Neutronic calculations for LLCB TBM blanket have been carriedut to estimate tritium production rate and radial profiles of nucleareating in the blanket. The nuclear heat deposited in the TBM has

een calculated for evaluating the thermal-hydraulic performancef the TBM. Radial profile of power density and the heat depositedn LLCB TBM are shown in Fig. 3. This figure shows the power densi-ies and the heat deposited in different zones in radial direction ofLCB module like Be, FW structure, 1st PbLi channel, RAFMS plate

view of LLCB TBM.

between 1st PbLi channel and the 1st CB zone, 1st CB zone, RAFMSplate between 1st CB zone and 2nd PbLi channel, etc. The nomen-clature of different zones in LLCB module is mentioned in Fig. 2. Thetotal heat deposited in the LLCB TBM is 0. 0.857 MW which com-prises of heat flux on FW is ∼0.241 MW and neutronic heat loadon entire LLCB module is ∼0.616 MW). The details of the neutronicanalysis can be obtained in Ref. [4].

3.2. Thermal-hydraulic analysis

The FE simulation of FW steady state thermal-hydraulic andstructural study has been carried out using ANSYS [5]. The heat loadon LLCB is the surface heat flux on the FW (average: 0.3 MW/m2, andpeak: 0.5 MW/m2) and the nuclear heat deposition on every com-ponent in the TBM module were used as inputs for thermal analysisand design. Fig. 4 shows the temperature distribution on full FWpoloidal length and 2-D cross sectional view of temperature pro-

file on two FW cooling channel. The maximum temperature of Beand RAFMS due to peak heat flux of 0.5 MW/m2 are 505 and 496 ◦Crespectively. For the average heat flux of 0.3 MW/m2 on FW thesetemperatures reduces down to 443 and 437 ◦C respectively. Thetemperature data obtained from above thermal-hydraulic analysis

1968 Paritosh Chaudhuri et al. / Fusion Engineering and Design 85 (2010) 1966–1969

Fig. 3. Radial profile of power density and the heat deposited in LLCB TBM.

Fig. 4. Temperature profile on FW for LLCB TBM heat fluxes.

Fig. 5. (a) Temperature contour in LLCB TBM, (b) temperature contour in PbLi loop only.

Paritosh Chaudhuri et al. / Fusion Engineeri

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ig. 6. Radial temperature profile in different CB zones for PbLi velocity of 0.1 m/s.

s used as the input for the thermal-stress analysis. The maximumtress on FW is 251 MPa at the fillet region, as compared with theield strength is ∼400 MPa at 510 ◦C. This stress value is below theermissible limits for the requirements of structure strength regu-

ations according to the 3Sm rules of ASME code for the boiler andressure vessel [6].

.3. 2-D CFD analysis

2-D CFD analysis has been carried out using FLUENT6.3 [7] tostimate the temperature distribution in different PbLi channels,ll CB zones and other materials inside the module. Fig. 5 showshe radial temperature profile in all PbLi channels PbLi velocity of.1 m/s (Fig. 5a) and temperature profile in all different CB zoneslong with the for PbLi channels are shown in Fig. 5b. It shows theemperature variation in all five vertical CB zones and six verti-al PbLi channels. Fig. 6 shows how the temperatures of differentB zones vary radially within their radial thickness. It shows that

he peak temperature of ceramic breeder occurs at 5th CB zone∼492 ◦C). The minimum and maximum temperature in all CBones lies between 485 and 492 ◦C. Analysis has also been carriedut for different PbLi inlet flow velocities to optimize the flow foreeping the PbLi, FMS and CB zones within their temperature limits.

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ng and Design 85 (2010) 1966–1969 1969

4. Conclusions

In this study the thermal-hydraulic and flow analyses have beencarried out for different PbLi inlet flow velocities to optimize theflow for keeping the PbLi, FMS and CB zones within their tempera-ture limits. It has been seen that for the PbLi velocity of 0.1 m/s, theall CB zone3s in the LLCB modules can be kept within their speci-fied temperature window. The results of thermo-hydraulic analysisshow that the coolant flow parameters and the corresponding per-formance of TBM are satisfactory. Further 3-D thermal-hydraulicand flow analyses are required in order to final optimization theLLCB TBM design. Structural design of the TBM is under progress,based on this, the final performance analysis need to be carried out.Various R&D activities such as PbLi loop technologies, tritium tech-nologies and manufacturing feasibility studies of the LLCB TBM isalso under progress. Different mock-ups of FW will be fabricatedto validate the design. An experimental high pressure helium loopwill be built in order to prove the thermo-hydraulic capability ofthe TBM to test mock-ups under similar conditions to ITER TBM.Design, analysis, and optimization of process integration and safetyanalysis for LLCB TBM system are initiated. Mechanical design ofthe process system for the PbLi cooling loop, high pressure heliumcooling loop and the helium purge gas loop along with the safetyanalysis and associated auxiliary systems of LLCB TBM are underprogress.

References

1] E. Rajendra Kumar, C. Danani, I. Sandeep, Ch. Chakrapani, N. Ravi Pragash, V.Chaudhari, et al., Preliminary design of Indian Test Blanket Module for ITER,Fusion Engineering and Design 83 (2008) 1169–1172.

2] Paritosh Chaudhuri, C. Danani, V. Chaudhari, C. Chakrapani, R. Srinivasan, I.Sandeep, et al., Thermal-hydraulic and thermo-structural analysis of first wallfor Indian DEMO blanket module, Fusion Engineering and Design 84 (2009)573–577.

3] Paritosh Chaudhuri, Status of engineering design & analysis for Indian TBMs, in:Presented at ITER TBWG-20 Meeting, November 5–7, Aix-en-Provence, France,2008.

4] Design Description Document for ‘Indian Lead–Lithium cooled Ceramic Breeder

(LLCB) Blanket’; version—1.0, Report to the ITER Test Blanket Working Group(TBWG), April 2008.

5] ANSYS® Release 10.0, ANSYS Inc.6] Am. Soc. of Mech. Engg., ASME, Boiler and Pressure Vessel Code, Section—III,

2004.7] Fluent, Users Guide 6.3, Fluent Inc, 2006.