G. Federici ITER JWS Garching.


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Materials Choice and Building Outline of ITER PFCs. G. Federici ITER JWS Garching. Plot Highlights of PFC configuration and material choice Disintegration amid transient warmth loads Staying open inquiries Outline. 2 nd SOL and Divertor Material science ITPA Meeting,
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Materials Selection and Engineering Design of ITER PFCs G. Federici ITER JWS Garching Outline Highlights of PFC configuration & material determination Erosion amid transient warmth burdens Remaining open inquiries Summary 2 nd SOL and Divertor Physics ITPA Meeting, Ioffe Institute, St. Petersburg - July 14-17, 2003 G. Federici, ITER

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ITER Rationale for material determination Present decision: 3 distinct materials G. Federici, ITER

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Strike focuses 0.56 2.35 1.34 4.23 3.47 ITER Divertor outline loads/lifetime Total power Q  150 MW Nominal surface warmth loads q = 10 MW/m 2 , ï\' = 400-500 sec, N = 3000 cycles (1 st div.) Transient warmth load q = 20 MW/m 2 , ï\' = 10 sec, N = 300 cycles (i.e., 10%) Disruption heat load Q = 10-100 MJ/m 2 , ï\' = 0.1  10 ms, N = 300 occasion (i.e., 10%) Ion flux parameters J = 10 21 - 10 24 m - 2 s - 1 , E = 10-100 eV Neutron load J (E>0.1MeV)  10 18 m - 2 s - 1 , D = ~0.1 dpa Other factors electromagnetic burdens (P  4 M Pa ), H environment, and so forth. W/m 2 Code reenactment of surface warmth flux on divertor G. Federici, ITER

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ITER Design get together/support The PFCs and tape body consolidate to give satisfactory protecting to the vessel and the curls. The divertor includes 54 tapes introduced in ITER by means of 3 equi-divided taking care of ports. Every tape comprises of a tape body onto which are mounted 3 PFCs. These PFCs can be traded in hot cell with a specific end goal to repair or to change the geometry of the divertor. A few complete trades are predicted amid the life of ITER. The tapes are precisely situated in the vessel such that each PFCs is adjusted inside ±2mm to regard to the PFCs on neighboring tapes. G. Federici, ITER

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Initial operation technique Current method is to at first introduce CFC on the objectives ITER Tungsten has still instabilities because of melt layer misfortune amid disturbances and ‘large’ ELMs. Keep up choice to change to an all-W divertor, former or amid T-operation. This alternative will be considered on the off chance that we don\'t succeed in alleviating the impacts of T co-testimony ( should be to be resolved amid D-stage ): Design moderation/temperature customizing. Blended material impacts (=> need to utilize existing tokamaks ). we come up short in creating dependable and compelling procedures of in-situ tritium evacuation, which should be illustrated/tried in tokamaks. there is generous advancement in relieving warmth burdens amid interruptions and ELMs. W CFC Urgent requirement for improvement PMI diagnostics to be tried approved in existing tokamaks and amid right on time operation with D in ITER. G. Federici, ITER

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ITER First-divider configuration loads/lifetime Total power Q  690 MW Surface warmth loads q = 0.25 MW/m 2 (avg.) 0.5 max. ï\' = 400-500 sec, N = 30000 cycles Disruption heat load None. VDEs: q = 60 MW/m 2 , ï\' = 300 ms N=300 cycles (1%), Neutron load 0.56 MW/m 2 (avg.)/0.78 (max) D = ~1 dpa. 412 cover modules connected to the vessel . ~4.5 t/module RH requirement. steel protecting piece isolate first divider boards. G. Federici, ITER

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ITER Design get together/upkeep Separate first-divider to minimize the operational waste Each sweeping module is joined with a changeless water cooling complex by two channels. The FW part repairable and/or replaceable in hot-cell. The modules are kept up by an extraordinary remotely determined in-vessel transporter embedded through the central port. G. Federici, ITER

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ITER Separate first-divider ideas The FW has 4 or 6 separate boards relying upon the choice decided for FW connection. Choice A: connection with jolts and little shear ribs to bolster EM loads and to avoid sliding because of warm extension. Choice B: focal pillar connection joined with the shield hinder on the back side . G. Federici, ITER

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ITER Remote taking care of arrangement taking into account requirement for booked and unscheduled upkeep and alterations, probability for support, and effect on operations and accessibility Divertor is Class 1: Requires planned support or substitution. Part outline and RH hardware and strategies, advanced to guarantee undertaking consummation inside of a base time. Practicality of upkeep undertakings exhibited with R&D amid EDA. Showing utilizing genuine parts amid beginning gathering before dynamic period of operation is exceptionally attractive. Cover is Class 2: Do not require booked but rather likely unscheduled or extremely rare support. Segments are intended for full remote repair or substitution however “minimisation of repair is subordinate to thought on atomic execution and reliability”. Plausibility of support errands halfway exhibited with R&D amid EDA. Show utilizing genuine segments amid beginning gathering before dynamic period of operation is attractive. G. Federici, ITER

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ITER Maintenance time gauges In-vessel parts are expelled from the VV by 4 tropical ports, 3 divertor ports and (?) upper ports (EC and diagnostics). Divertor tape renovation 18 tapes - > 1 RH port => 2 months (7 working day/week, 2 (8 hrs) wk shifts/day, 1 barrel transporter (8 hrs/shift/day). 3 RH ports in arrangement ==> 6 months Replacement of 1 single flawed tape ≤ 2 months !! Cover support Replacement of some shield modules is likely because of nearby harm. Substitution of the full first divider is in no time not foreseen, but rather ought to be practical. 1 cover module: 25 days 1 toroidal row: 32-151 days * All sweeping modules: 276-916 days * Depends on # of conveyed IVT. Current outline strategy: little number of extra parts. G. Federici, ITER

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Critical PFC outline/operation issues ITER Heat burdens and disintegration amid sort I ELMs Ongoing energetic ITPA exertion, EU PWI team Heat burdens and disintegration amid warm extinguish disturbances and VDEs Ongoing vivacious ITPA exertion, EU PWI team Hydrocarbon transport/T codeposition in remote zones and evacuation Surveys in tokamaks (EU PWI team) Identify source and sinks. Testimony examples and reliance on operation parameters. Arrangement of fumes. Research facility reenactments (EFDA, EU PWI team) Sticking of radicals. Impacts of temperature, H/C proportions, and so forth. Blending of materials (C/Be) G. Federici, ITER

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Heat burdens and disintegration amid sort I ELMs Tolerable ELMs in ITER set by materials: T plate ELM < physical points of confinement (evap., dissolving). ITER Temp. journeys amid ELMs=> no tightening!!! Discriminating parameters are: (1) vitality misfortune from platform, (2) part coming to the divertor, (3) wetted range, (4) term/state of ELM warmth beat. Learning of these amounts still questionable. Triang. ELMs, 0.3 ms, 1 MJ/m2 (1) BOL: 20 mm CFC, 10 mm W. (2) EOL: 2 mm CFC, 2 mm W. Just close surface ≤400âµm => Steep Temp. slopes G. Federici, ITER

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Tolerable ELM estimate countless >1 MJ/m 2 can\'t go on without serious consequences ITER In ITER: W ped ~ 100 MJ, n ped ~8x10 19 m - 3 , T ped ~3.5 keV, d w~10 cm =>low collisionality ( n * ped ~0.04) Scaling to ITER - D W ELM/W ped : n * ped : 15%-20% - > 15-20 MJ. t/: 10%-15% - > 10-15MJ. n ped/n GW : 4%-5% - > 4 - 5 MJ. 50-70% of vitality is kept in divertor; Wetted range: 4.5 - 9 m 2 with humble (~50%) widening; effect time > t/(~240 µs ): t IR/t/=1.5-3.1. CFC and W show comparable ELM disintegration lifetime. Lifetime for W relies on upon melt layer misfortune. Disintegration lifetime shorter if one utilize a measurable assessment of ELM parameters. More slanted divertor target performs better. Similarity of between ELM plasmas with sporadic W surface remains an issue. Extra plainly visible disintegration instruments because of high recurrence beating and high temperature journeys confined in the close surface (<400âµm). G. Federici, ITER

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A non-unimportant portion of the ELM vitality from the primary plasma achieves the principle chamber divider ITER D W ELM div ~ 50 – 80 % of D W ELM dia Despite limited l @ELM D W ELM div/D W ELM ~ 0.6 Where does the R est of D W ELM go ? Toroidal Asymmetries (most likely No) Main Chamber (presumably Yes) Transiently upgraded P RAD ELM (likely No) JET – Type I ELM G. Federici, ITER

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Effects of sort I ELMs at the fundamental chamber divider ITER Expect communication with projecting surfaces (~1 m 2 ) ==> middle of the road just 1-2 MJ relying upon span (if ≥ 1 ms no liquefying of W) G. Federici, ITER

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Thermal Quench Disruptions Only a small amount of the vitality achieves the divertor and is appropriated rather consistently. ITER Evolution of the surface temperature close and a long way from strike focuses in a D W th =5.6 MJ G. Matthews et al., nineteenth IAEA FEC 2002, Lyon To show up in Nucl. Combination. On the off chance that the JET results extrapolate to ITER then disturbances would not harm a W target. Be that as it may, it is not known right now where and by what forms the missing and warm an attractive energies are saved in the primary chamber. On the off chance that this vitality testimony is not adequately uniform, then extra harm to fundamental chamber parts may be normal. G. Federici, ITER

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ITER warm extinguish particulars Need to be returned to on the premise of the new discoveries (progressing) ITER Case 1 Case 2 If vitality stored in the divertor amid interruptions is < 40% of the warm vitality with a request\'s widening 20-30 times, vitality thickness at the objective stays beneath the dissolving edge for W. Some shallow liquefying can by the by occur a few times . Concern stays on whether era amid ELMs/disturbances of surface inconsistencies in tungsten because of liquefying, and in CFC because of fragile devastation, may shape problem areas amid ordinary operation

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