Overview of EUROfusion PEX strategy, DTTs role and summary of ... · Overview of EUROfusion PEX strategy, DTTs role and summary of assessment reports DC. McDonald , T. Donné, X

Overview of EUROfusion PEX strategy,

DTTs role and summary of assessment

reports

DC. McDonald , T. Donné, X. Litaudon, M. Reinhart, M. Turnyanskiy, D. Borba

DC McDonald | Overview of EUROfusion PEX strategy | DTT Workshop, Frascati | 19 Jun 2017 | Page 2/19

1. European fusion roadmap prioritised plasma exhaust and alternative solutions for risk mitigation

− EFDA Fusion Electricity: A roadmap to the realisation of fusion energy

2. EUROfusion focused considerable effort on assessing alternative concepts at the proof of principle level

− Assessment of the DEMO compatibility of alternative plasma exhaust solutions

3. Two PEX Ad-Hoc Group reports defined EUROfusion strategy:

− Report of the Ad-Hoc Group on “Strategy for the Plasma Exhaust” (“PEX AHG”) – Phase 1

− Report of the Ad-Hoc Group on “Strategy for the Plasma Exhaust” (“PEX AHG”) – Phase 2

4. Call launched for PEX upgrades/new devices to enable implementation of the strategy. Response from beneficiaries:

− ENEA DTT Divertor Tokamak Test facility project proposal

− 9 other proposals for upgrades and new devices

5. PEX Assessment Panel assessed proposals

− Plasma Exhaust Assessment Panel Report (PEX Assessment Panel Report)

6. PEX upgrade strategy

− Report on PEX Upgrade Strategy

Steps in Plasma Exhaust strategy


• The plasma exhaust (Mission 2) executive summary

of the European fusion roadmap (2012) states:

− “A reliable solution to the problem of heat exhaust is probably the

main challenge towards the realisation of MCF.

− “The risk exists that the baseline strategy pursued in ITER

cannot be extrapolated to a FPP.

− “Hence, in parallel to the programme in support of the baseline

strategy, an aggressive programme of alternative solutions for

the divertor is necessary.

− “Some concepts are already being tested at the PoP level and

their technical feasibility in a FPP is being assessed.

− “Since the extrapolation from PoP devices to ITER/DEMO based

on modelling alone is considered too large, a dedicated test on

specifically upgraded existing facilities or on a dedicated Divertor

Tokamak Test (DTT) facility will be necessary”

1. European fusion roadmap (v1) on DTT


EU-DEMO

Consistent Concept

Commence Construction Electricity

Production Mission 4 – Tritium breeding Mission 5 – Safety Mission 6 - Integrated DEMO design

Scie

nce

& T

ech

no

logy

Bas

is fo

r fi

rst

FPP

s

Mission 8 – Stellarator

2050

Mission 7 – Lower cost, innovations

ITER Q = 10 Q = 5 long pulse

From draft revised Roadmap

Mission 3 – Materials MTR DONES

IFMIF

Towards stellarator FPP?

Mission 1 – Plasma scenarios Mission 2 – Heat exhaust

Mission 1 – Plasma scenarios Mission 2 – Heat exhaust

Mission 4-7 – Maximise ITER input to DEMO

2020 2030 2040 2017


• EUROfusion has significantly increased the European physics and R&D effort on plasma exhaust

− See talk of H Reimerdes

• Significant activity and resources were directed to alternative divertor concepts, through the dedicated Work Packages DTT1 and DTT2 and the supporting upgrades, experiments and analysis in WPPFC, WPMST1 and WPMST2

• A major milestone was the report

− Assessment of the DEMO compatibility of alternative plasma exhaust solutions

• This assessed the compatibility of the proposed alternatives with DEMO

• No show-stoppers for any of the concepts were found and the main costs and benefits for each were identified

• The report supported an ongoing R&D programme and recommended the necessary next steps

2. EUROfusion work on plasma exhaust (2014-)


See talk of H Zohm

• PEX AHG reports identified physics and technology gaps and developed a broad strategy for plasma exhaust within the four identified areas

− Area A: Conventional materials and PFUs

− Area B: Conventional divertor

− Area C: Alternative materials and PFUs

− Area D: Alternative divertors

• Within each area, the broad tasks and milestones required to address the physics and technology gaps were outlined developing the solutions at the levels of

− Proof of Principle

− Demonstration

− Qualification, including implementation on DEMO

• Broad dates for the tasks and milestones are indicated, in line with the DEMO design, construction and operation points and the schedules of ITER, JT-60SA etc

3. Outline of PEX AHG reports


3. PEX AHG strategy: alternative divertor configurations

Control detachment in MST&JET at high

Psep

Demonstrate exhaust in Q=10

scenario in MST/JET(DT)

Verify SOLDIV codes (incl. first principles transport elements)

Proof of principle phase

Demonstration phase

Systematic study of seed impurities

(MST&JET)

Interpretation with SOLDIV codes

(quantitative match)

Development of ITER and DEMO

compatible sensors for detachment

•Q

=10

exh

aust

sch

eme

read

y fo

r u

se in

ITER

•

Ass

ess

hig

h f

rad f

or

ITER

Q=5

(P A

UX u

pgr

ade)

an

d D

EMO

ED

A

Qualify detached divertor under

ITER Q=10 conditions

Verify full predictive SOLDIV

code

•H

igh

Pse

p d

iver

tor

dem

on

stra

ted

at

low

fra

d,c

ore

•A

sses

s h

igh

fra

d,c

ore

sce

nar

io f

or

DEM

O c

on

stru

ctio

n

Demonstrate high frad steady

state scenario in JT-60SA(W)

Verify first principles model for confinement

at high frad,core

Demonstrate high frad steady

state scenario in ITER Q=5

Verify coupled core-SOLDIV

model

Hig

h f

rad

co

re s

cen

ario

dem

on

stra

ted

at

inte

rmed

iate

Pse

p

Qualification phase

Develop high frad steady state scenario in

MST(W)&JT-60SA(C)

Characterise first wall loads in high frad,core

scenario (MSF, JET, JT-60SA)

Develop first principles model for confinement

at high frad,core

Experimental characterisation

of confinement at at high frad,core

Develop physics models for

confinement at high frad,core

Qu

alif

y co

mb

inat

ion

of

hig

h P

sep

and

hig

h f

r ad

,co

re in

DEM

O

Implement in DEMO

Now 2020 2027 2035 2039 ≥ 2050

End of H2020 programme start ITER operation ITER Q=10 ITER steady state start DEMO ops start JT-60SA operation JT-60SA steady state (C) JT-60SA steady state (W) start DEMO construction (≈2040) start MSF/long pulse operation JET DT complete start DEMO EDA (≈2030)

•R

ead

y to

imp

lem

ent

det

ach

men

t co

ntr

ol i

n M

SF a

nd

JET

•

Ass

essm

ent

of

stat

us

of

con

ven

tio

nal

exh

aust

sch

eme

(aro

un

d

20

22

, to

geth

er w

ith

alt

ern

ativ

e co

nce

pts

)


• Call launched for PEX upgrades/new devices to enable implementation of the strategy. Response from beneficiaries:

− ENEA DTT Divertor Tokamak Test facility project proposal

− 9 other proposals for upgrades and new devices

• Panel of international and European experts assessed all 10 proposals including meetings and questions to all proponents

• Panel found that all proposals contributed to the PEX strategy

• Panel reported on the technical and scientific strengths and weaknesses of each proposal and outlined the degree to which they contributed to the PEX strategy

4-5. Call and Plasma Exhaust Assessment Panel Report


• The PEX upgrade strategy was developed by the

EUROfusion PMU using the DTT1, PEX AHG and

assessment panel reports as the technical basis

• The main step was to optimise the gaps that could

be addressed by the upgrades in a cost effective

way

− Here gaps means gaps in our facilities

• The scope was to prioritise the conventional (ITER)

divertor and the phase up to ≈2027. However, the

strategy beyond 2027 was also considered.

• The home labs of all proponents, including ENEA-

DTT, were visited as part of the exercise

6. Plasma exhaust (PEX) upgrade strategy


6. Gaps with and without upgrades

Area D: Alternative divertor

Task Description Gaps

without

upgrade

Gaps

with

upgrade

Comments

Proof of Principle Phase (≈2014-2020)

D1.1 Identify theoretically and

experimentally the mechanisms

that can give advantages

None None+ Based on initial data particular from AUG,

MAST-U and TCV.

After 2020, AUG tungsten environment with

its high Ptot/R will provide key information on

Snowflake, X-divertor, and conventional

double null configurations. MAST-U has a

unique ability to investigate the Super-X in

the existing configuration. These Phase I

experiments should determine the necessity

of heating upgrades

D1.2 Demonstrate (some of) the

expected advantages qualitatively

Gap None+ As for D1.1. Relevant diagnostic upgrades

might be required

D1.3 Identify causes of impact (positive

and negative) on core scenarios

(e.g. pedestal, impurities)

Gap None+ As for D1.1

D1.4 Assess in-principle feasibility of

contender concepts at DEMO scale,

incl RAMI & TBR and impact on

DEMO design

Gap None+ This is a study, but requires the resolution of

D1.1, D1.2 and D1.3 first


PEX upgrade selection and broad schedule

2017 2018 2019 2020 2021 2022

WEST

TCV

MAST-U(Phase II)

MAST-U(Phase I)

JSI

FZJ

AUGUpgrade in progress

Operation to exploit upgrade

Phase II assessment through KPI

Now ≈ End of Proof of Principle phase

Upgrade in progress interlaced with operation


1. Following the DTT1 report, an internal expert group should study engineering aspects of alternative divertor and material solutions for DEMO.

2. Development of a roadmap for liquid metals, that takes the existing programme to a possible DEMO solution on a realistic time scale.

− To be proposed in Jul 2017. Foreseen to include an integrated LM divertor conceptual design and a gate review (2019)

3. Critical design studies for liquid metals required for tasks identified by the PEX AHG

4. Critical design studies for alternative divertor configurations required for tasks identified by the PEX AHG

5. An extensive and cross-EUROfusion programme of theory and modelling is clearly required to support the activities and extrapolate the results to ITER and DEMO

Critical support work


• All gaps in first phase (2017-2020) are adequately filled by the proposed upgrades and many (all for Area D) are adequately filled in the second phase (2021-2027):

− Area A: Conventional materials and PFUs − Area B: Conventional divertor − Area C: Alternative materials and PFUs − Area D: Alternative divertors

• Priority of PMU is on A: conventional materials and PFUs; and Area B: the conventional divertor

− All gaps could be filled if JET where to be extended until 2024 with a modest divertor refurbishment (in development)

• Beyond 2027, the assumption is:

− JT-60SA, ITER, DONES and DEMO (+ accompanying smaller devices) are sufficient to address the conventional materials and divertor areas (A and B)

− If, a candidate alternative solution is demonstrated, a dedicated DTT or upgrade of the next generation devices (JT-60SA or ITER) would be required

− Any such strategy must have minimal impact on the DEMO construction start date

Conclusion of PEX facility gap analysis


Budget for PEX upgrade selection

The budget for the projects immediate approved (Phase I) or for approved after they have proven additional KPIs after a new assessment (Phase II) is:

Budget / k€ Period

Total 2017-2018 2019-2020 2021-2024

TOTAL Phase I+II 8,250 17,783 7,452 33,485

Construction of a dedicated ENEA-DTT, or similar device, is not foreseen to begin before ≈2022


• The PMU noted and supported the PEX Assessment Panel Report findings:

− “At present there is insufficient knowledge to predict which alternative configuration will prove the most promising and justify the construction of a large new facility”.

• Which are in line with the AHG on ‚Strategy for the Plasma Exhaust‘ (‚PEX AHG‘) - Phase 2:

− “We find it too early to tell if the alternatives are promising enough to take this step now and hence propose a rigorous assessment in ≈2022, when more input from experiments (possibly including PEX upgrades), modelling and DEMO integration studies will be available. This assessment must also include the conventional approach to put the expected benefits of the alternatives in perspective.“

• The project should be put on hold until the results from the selected upgrades are analysed, confirming the benefits of the alternative configurations and making a down selection to a possible alternative divertor concept.

Proposed strategy on ENEA-DTT


• The PMU noted and supported the PEX Assessment Panel Report findings:

− “The DTT proposal appears well suited to investigate the Snowflake and x-divertor configurations; however, other alternative configurations (e.g. Super-X/ long legged divertor) are not clearly accommodated and were not reviewed.”

− “At present there is insufficient knowledge to predict which alternative configuration will prove the most promising and justify the construction of a large new facility.”

− “If the proposed DTT were immediately funded and focused on alternative divertors from the start and if funding were available for the heating upgrades early on, then it is possible, but difficult for it to contribute to the 2035 decision point for alternative divertors.” o Such an upgrade would significantly increase construction costs

− “the panel recommends that a decision on proceeding with the proposed DTT be delayed until sufficient input has been obtained from ASDEX Upgrade, MAST Upgrade and TCV. This would allow determination of whether a dedicated “DTT” facility” is needed or not. It would also reduce the complexity of a dedicated “DTT” facility by being able to focus the design on a preferred alternative divertor solution.” o Critically, it must be considered that the ongoing assessments find that there is no feasible

alternative divertor solution

− “In addition, the current scientific and technical experience with large alternative materials for plasma exhaust is insufficient for the design of a large new facility.”

− “To properly address compatibility of the core with the divertor for DEMO-like conditions,….. even the highest powers proposed are marginal at Ptot≈45 MW.”

Proposed strategy on ENEA-DTT


• Immediate Support of ENEA-DTT instead of placing

on hold until 2022

− Motivation: that ENEA could likely miss the national resources

(≈115 M€) or the related loan from EIB (≈ 250 M€)

• Additional risks of committing resources prior to the

down selection of alternative divertor concepts

− ENEA-DTT may not be needed / not well suited to test the

selected DEMO design of a conventional / alternative divertor

concept

• A significant number of technical and budgetary

concerns would have to be addressed by a Phase II

Panel for DTT

Alternative option for ENEA-DTT


Alternative option for DTT

Proposal Period

Total budget / k€ 2017-2018 2019-2020 2021-2024

All Phase I+II 8,250 17,783 7,452 33,485

Optional DTT 3,467 39,818 16,714 60,000

TOTAL 11,717 57,601 24,166 93,485

The following table gives the provisional budget for immediate funding of DTT compared to the budget of all other Phase I+II projects.

This optional allocation for 2017-2018 is within the existing unallocated resources for Mission 2.

The allocation for 2019-2020 would be an ≈20 M€ increase from 2018. This would either come from an increase in the total EUROfusion budget or cuts elsewhere in the programme.

The proposed allocation beyond 2020 is also much increased.

EUROfusion General Assembly agreed that this EUROfusion DTT workshop will be held to discuss whether it makes sense to advance the ENEA DTT proposal.


- Since 2012, the leading experts have undertook an extensive programme of plasma exhaust studies/reviews of alternative concepts (5 bodies, 6 reports)

- Conclusions are consistent and result in strategy to approve 6 PEX upgrade projects (AUG, FZJ, JSI, MAST-U, TCV, WEST) and delay a decision on a full DTT until down selection of alternative divertor concepts (≈2022)

- LM divertor roadmap, after a EUROfusion Workshop,to be developed

- This has progressed and roadmap expected to be complete by the end of 2017

- EUROfusion DTT workshop to be held to discuss whether it makes sense to advance the ENEA DTT proposal, specifically to:

1. discuss the programmatic goals of the ENEA proposed DTT project in the frame of the EUROfusion PEX strategy and Roadmap

2. to get input from the European fusion research community into the ENEA proposed DTT project

- The workshop results will be fed into the PEX strategy group

- No decision is taken on the DTT PEX proposal, so the options remain:

1. A Phase II assessment for DTT

2. DTT2 is closed and the DTT decision postponed to ≈2022

Present status: approved at EUROfusion

General Assembly in Apr 2017


Additional slides


Gaps with and without upgrades

Area A: Conventional materials and PFUs


without

upgrade

Gaps

with

upgrade

Comments


A.1.1 Assess plasma effects on ITER

component design

None None+ Significant contribution by WEST proposal,

providing it demonstrates its merits as an

integrated test facility

A.1.2 Determine operation conditions and

materials requirements

None None+ Major contribution to MTRL / material

assessment with regard to beryllium /

tritium loaded / irradiated samples by FZJ

proposal

A.1.3 Evaluate applicability of existing

design codes

None None+ Significant contribution by FZJ proposal

A.1.4 Identify and assess interfaces None+ None+

A.1.5 Develop machining and joining

technologies and reliable low cost

manufacture

None+ None+

A.1.6 Demonstrate materials properties in

linear devices

None None+ Major contribution by FZJ proposal

A.1.7 Demonstrate materials compatibility

with plasma in MSF/JET

None+ None+



Area A: Conventional materials and PFUs


without

upgrade

Gaps with

upgrade

Comments

Demonstration Phase I (≈2021-2027)

A.2.1 Integrated performance of ITER PFUs

under plasma conditions (MSF)

Gap None+ Major contribution by WEST proposal

A.2.2 Safety analysis Gap Gap Remaining issues could be addressed by

JET

A.2.3 Qualify materials and prototypes in

fission test reactors

Gap None+ Major contribution by FZJ proposal

A.2.4 Establish machining and joining

technologies

Gap None+ Major contribution by FZJ proposal

A.2.5 Integrated performance of DEMO

component under plasma conditions

(MSF)

Gap None Assuming eventual agreement on DEMO

components and purchase of test

samples

A.2.6 Assess impact of safe PFC operation

on high performance plasma

scenario (MSF)

Gap Gap Remaining issues could be addressed by

JET

A.2.7 Develop predictive modelling of

combined loads

Gap None Significant contribution by FZJ proposal.



Area B: Conventional divertors


without

upgrade

Gaps with

upgrade

Comments


B1.1 Systematic study of seed impurities

(MST & JET)

None+ None+

B1.2 Interpretation with SOLDIV codes

(quantitative match)

None+ None+

B1.3 Development of ITER and DEMO

compatible sensors for detachment

None None+ AUG to address this issue, with support

from MAST-U, TCV and WEST.

B1.4 Experimental characterization of


None+ None+

B1.5 Develop physics models for


None+ None+



Area B: Conventional divertors


without

upgrade

Gaps

with

upgrade

Comments


B2.1 Control detachment in MST and JET

at high Psep

None None JET could make a significant contribution. AUG is

important, but AUG project itself does not have

large impact.

B2.2 Demonstrate exhaust in Q = 10

scenario in MSF/JET(DT)

None None As for B2.1

B2.3 Verify SOLDIV code (including first

principles transport elements)

None None As for B2.1

B2.4 Develop high frad,core and frad,div steady-

state scenario in MST (W) and JT-

60SA (C)

Gap Gap JET could make a major contribution with support

from WEST

B2.5 Characterize first wall loads in high

frad,core scenarios (MSF, JET, JT-60SA)


from WEST

B2.6 Develop first principles models for



from WEST



Area C: Alternative materials and PFUs


without

upgrade

Gaps

with

upgrade

Comments


C1.1 Integrated concept, including liquid

metal loops, plasma compatibility,

etc (on paper)

Gap Gap OLMAT-TJII could make a significant

contribution, but subjects such as recovery

and closed loops, restricting core

contamination etc. are not addressed in the

proposal. Therefore, still a large gap remains

C1.2 Reactor relevant target design

survives ≥ 10 MW/m2 in steady

state (linear device)

Gap Gap Some concerns on test of steady state

C1.3 Qualification of suitable material

(Li, Sn, LiSn): T-retention and

operational temperature window

Gap Gap As for C1.2., e.g. redeposition behaviour will

be different due to interaction of vapour ions

with high energy neutrals rather than with

low energy plasma, giving limitations to the

interpretation. Relevant diagnostic upgrades

C1.4 Assess in-principle feasibility of

contender concepts at DEMO scale

Gap Gap This is a study, but requires the resolution of

C1.1, C1.2 and C1.3 first



Area C: Alternative materials and PFUs


without

upgrade

Gaps

with

upgrade

Comments


C2.1 Compatibility with main and

divertor plasma (e.g. different

recycling conditions), ≥2025

Gap Gap Could be addressed to some degree by the

COMPASS project

C2.2 Develop theoretical description

on a first principle model (both

PFU and plasma impact)

Gap Gap

C2.3 Demonstrate closed loop function

and target performance in a

realistic tokamak environment,

≥2025

Gap Gap

C2.4 Advance the technical

implementation on a DEMO to

CDA level

Gap Gap This is a study, but requires the resolution

of C2.1, C2.2 and C2.3 first

Many gaps remain in Area C. Must launch an activity to produce, by Dec 2017, a credible roadmap for liquid metals to DEMO.



Area D: Alternative divertor


without

upgrade

Gaps

with

upgrade

Comments

Demonstration Phase I (≈2021-2027) D2.1 Demonstrate benefits of

advanced divertor quantitatively

supported by first-principle

models in existing devices

Gap None As for D1.1

D2.2 Advance the technical

implementation on a DEMO to

CDA level

Gap None This is a study, but requires the resolution

of D2.1 and D2.3 first

D2.3 Demonstrate path to integrate

with relevant (improved?) core

scenario using experiments and

first-principles models

Gap None As for D2.1


Budget for Phase I+II

Proposal Period

Total budget / k€ 2017-2018 2019-2020 2021-2024

AUG 1,145 2,475 0 3,620

FZJ 1,398 3,261 0 4,660

JSI 60 0 0 60

MAST-U (Phase I) 1,992 1,453 960 4,405

MAST-U (Phase II) 569 3,033 2,892 6,494

TCV 1,042 655 0 1,697

WEST 844 5,106 0 5,949

Support activity 1,200 1,800 3,600 6,600

TOTAL Phase I+II 8,250 17,783 7,452 33,485

The following table gives the total budget of the Phase I+II projects in the 3 periods 2017-2018, 2019-2020 and after 2020. Except for MAST U, it has not yet been possible to obtain an estimate of the depreciation costs for the equipment for each project. The “Support Activity” budget includes additional resources for critical support work and the exploitation of the upgrades through EUROfusion supported experiments and analysis. It is not including resources for theory and modelling.

Documents

Overview of EUROfusion PEX strategy, DTTs role and summary of ... · Overview of EUROfusion PEX strategy, DTTs role and summary of assessment reports DC. McDonald , T. Donné, X