ITER
Test Blanket Module (TBM)
Program
Briefing to DOE/OFES
and US ITER Project Management
Mohamed Abdou
Video Conference, September 9, 2004
1
Outline
I.
What is ITER TBM?
II.
Why is ITER TBM Critical?
Why must the US participate in ITER TBM?
(includes tritium supply issue, impact on physics, focus for
materials and technology)
III.
History of ITER TBM, current TBWG Activities,
and other Parties’ TBMs
IV.
US Strategy for ITER TBM and description of
effort and selected concepts
V.
Programmatic Issues requiring DOE and US
ITER management attention
- Part of US ITER Organization
- Focus for Plasma Chamber, Materials, and other programs
- Resources
- Formal International Agreements
2
What is the ITER TBM Program?
 Breeding Blankets will be tested in ITER, starting on Day
One, by inserting Test Blanket Modules (TBMs) in specially
designed ports.
 Each TBM will have its own dedicated systems for tritium
recovery and processing, heat extraction, etc. Each TBM will
also need new diagnostics for the nuclear-electromagnetic environment.
 Each ITER Party is allocated limited space for testing two
TBMs. (Number of Ports reduced to 3. Number of Parties
increased to 6).
 ITER’s construction plan includes specifications for TBMs
because of impacts on space, vacuum vessel, remote
maintenance, ancillary equipment, safety, availability, etc.
 The ITER Test Program is managed by the ITER Test
Blanket Working Group (TBWG) with participants from the
ITER International Team and representatives of the Parties.
3
ITER Operational Plan Calls for Testing
Breeding Blankets from Day 1 of Operation
H-Plasma Phase
D Phase
First DT plasma phase
Accumulated
fluence =
0.09 MWa/m2
Blanket
Test
4
TBM Roll Back from ITER 1st Plasma
Shows R&D must be accelerated now for TBM Selection in 2005
EU schedule for Helium-Cooled
ITER First Plasma
Pebble Bed TBM (1 of 4 TBMs Planned)
02 03 04 05 06 07 08 09 10 11 12
13 14 15 16 17 18 19 20 21 22 23 24 25
HCPB Programme
PB Material Fabrication and
Char. (mech., chem, etc)
Out-of-pile pebble bed
experiments
Pebble bed Irradiation
Programme
Modelling on Pebble beds
including irradiation effects
Key issues of Blanket
Structure Fabr. Tech.
HCPB Programme for ITER
Develop. and testing of
instrumentation for TBM
Develop. and testing of
components of Ext. Loops
TBM and Ext. Loop Mock-up
Design
TBM and Ext. Loops Mock-up
Fabrication
Operation of TBM and Ext.
Loop Mock-ups
A final decision on blanket
test module selection by
2005 in order to initiate
design, fabrication and outof-pile testing.
Final Design of TBM
Fabrication and qualification of
TBM and Ext. Loops
Operation in the Basic
Performance Phase of ITER
(Reference: S. Malang, L.V. Boccaccini, ANNEX 2, "EFDA Technology Work programme 2002 Field: Tritium
Breeding and Materials 2002 activities- Task Area: Breeding Blanket (HCPB), Sep. 2000)
5
ITER’s Principal Objectives Have Always Included
Testing Tritium Breeding Blankets
• “The ITER should serve as a test facility for neutronics,
blanket modules, tritium production and advanced
plasma technologies. The important objectives will be
the extraction of high-grade heat from reactor relevant
blanket modules appropriate for generation of
electricity.”
—The ITER Quadripartite Initiative Committee (QIC), IEA Vienna 18–19 October 1987
• “ITER should test design concepts of tritium breeding
blankets relevant to a reactor. The tests foreseen in
modules include the demonstration of a breeding
capability that would lead to tritium self sufficiency in a
reactor, the extraction of high-grade heat and electricity
generation.”
—SWG1, reaffirmed by ITER Council, IC-7 Records (14–15 December 1994), and
stated again in forming the Test Blanket Working Group (TBWG)
6
The US has been a leader in the science and
engineering of blanket testing in “ITER” for
20 years
• The US has made major contributions to the ITER
Test Program since early CDA (and, even earlier, INTOR)
• The US is widely acknowledged as the primary
“intellectual power” in fusion testing because:
– Many US studies in the 80’s and 90’s such as FINESSE,
VNS, etc, defined the FNT issues and testing
requirements
– The Fusion Engineering Science for “effective testing” in
fusion facilities has been developed mostly by the US
(search scholarly journals on the subject, it is dominated
by US authors)
7
II.
Why is ITER TBM Critical?
Why is it necessary for the US to
participate in ITER TBM?
8
Tritium Self-Sufficiency
Tritium self-sufficiency condition: Λa > Λr
Λr = Required tritium breeding ratio
Λr is 1 + G, where G is the margin required to account for tritium losses,
radioactive decay, tritium inventory in plant components, and supplying
inventory for start-up of other plants.
Λr is dependent on many system physics and technology parameters:
– plasma edge recycling, tritium fractional burn-up in the plasma
– tritium inventories (release/retention) in components
– efficiency/capacity/reliability of the tritium processing system, etc.
Λa = Achievable tritium breeding ratio
Λa is a function of technology, material and physics.
– FW thickness, amount of structure in the blanket, blanket concept (ITER detailed
engineering is showing FW may have to be much thicker than we want for T self
sufficiency)
– Presence of stabilizing/conducting shell materials/coils for plasma control and
attaining advanced plasma physics modes
– Plasma heating/fueling/exhaust, PFC coating/materials/geometry
– Plasma configuration (tokamak, stellerator, etc.)
9
ITER Blanket Testing is Essential to:
• Achieve a key element of the “ITER Mission”
• Establish the conditions governing the scientific
feasibility of the D-T cycle, i.e., determine the
“phase-space” of plasma, nuclear, material, and
technological conditions in which tritium selfsufficiency can be attained
- The D-T cycle is the basis of the current world plasma physics and
technology program. There is only a “window” of physics and technology
parameters in which the D-T cycle is feasible. We need to determine this
“window.” (If the D-T cycle is not feasible the plasma physics and
technology research would be very different.)
- Examples of questions to be answered:
-
Can we allow low plasma-edge recycling?
Is high plasma-edge recycling necessary for T self sufficiency?
Are advanced physics modes acceptable?
Is the “temperature window” for tritium release from solid breeders
sufficient for adequate TBR?
- Is there a blanket/material system that can exist in this phase-space?
10
ITER Blanket Testing is Essential to (cont’d):
• Achieve the most critical milestone in blanket and
material research: testing in the integrated fusion
environment
(ITER construction and operation is for the next 30 years. Without
such fusion testing, material and blanket research loses “focus”,
relevance: Why are we doing any research in these areas then?)
• Develop the technology necessary to install
breeding capabilities to supply ITER with tritium
for its extended phase of operation
• Resolve the critical “tritium supply” issue for
fusion development
- and at a fraction of the cost to buy tritium for large D-T burning
plasma
11
Other Reasons why the US should
Participate in ITER TBM
 Test critical technologies for any further US development of
fusion (CTF, DEMO, alternate confinement facilities, power
plants)
 Access R&D information from much larger ($10-20M per year)
blanket programs (EU and Japan) and other international
partners
 To build US knowledge, experience, and competence in fusion
nuclear and tritium technologies needed to develop practical
and safe DT fusion devices (Building competence takes
decades)
 Keep the door open for the US to be a world leader in fusion
again in the future
For a few million dollars’ expenditure on test blanket modules,
we will acquire vital data and develop critical technologies
– an additional excellent return on the billions of dollars
invested in ITER.
12
ITER Provides the First Integrated Experimental
Conditions for Fusion Technology Testing
• Simulation of all Environmental Conditions
Neutrons
Plasma Particles
Electromagnetics
Tritium
Vacuum
Synergistic Effects
• Correct Neutron Spectrum (heating profile)
• Large Volume of Test Vehicle
• Large Total Volume, Surface Area of Test
Matrix
13
Tritium Consumption and Production
Tritium Consumption in Fusion is HUGE!
55.8 kg per 1000MW fusion power per year
Production & Cost
• CANDU Reactors: 27 kg from over 40 years, $30M/kg (current)
• Fission reactors: 2-3 kg per year. It takes tens of fission reactors to supply
one fusion reactor.
$84M-$130M per kg, per DOE Inspector General*
Conclusions
• The cost of blanket development and ITER TBM is a fraction of the cost to
“purchase” tritium for a burning plasma facility such as ITER.
• “Availability” of external tritium supply for continued fusion development is
an issue.
• Large power DT facilities must breed their own tritium. (This is why ITER’s
extended phase was planned to install a tritium breeding blanket.)
*DOE Inspector General’s Audit Report, “Modernization of Tritium Requirements Systems”, Report DOE/IG-0632, December 2003,
available at www.ig.doe.gov/pdf/ig-0632.pdf
14
World Tritium Supply Would be Exhausted by 2025
if ITER Were to Run at 1000MW at 10% Availability
(OR at 500 MW at 20% availability)
Projected Ontario (OPG) Tritium
Inventory (kg)
30
25
CANDU Supply
20
w/o Fusion
15
1000 MW Fusion,
10% Avail, TBR 0.0
10
ITER-FEAT
(2004 start)
5
0
1995
2000
2005
2010
2015
2020
2025
2030
2035
2040
2045
Year
15
III. History of TBM, Current TBWG
Activities, and other parties’
TBMs
16
History of ITER Test Program: From prior to CDA to EDA to Now
(and why things are the way they are!!)
• Negotiations Prior to ITER CDA
--
Providing Capabilities for testing was a central
element in negotiating “Objectives” and “Design
Envelope”
--
Plasma physics parameters (steady state, pulse
length, etc.), wall loads, etc. were most
influenced by the need to do testing
--
Formal agreements have always had “Blanket
Testing” as a key ITER objective
• During CDA (and early EDA)
----
A powerful International “Testing Group” was
formed by ITER Management.
M. Abdou was asked to chair
Played a key role in defining ITER parameters
and features
17
Test Blanket Working Group (TBWG)
– TBWG was proposed by SWG-1 and established by the ITER Council (IC-7
RECORDS, 14-15 December 1994)
– A formal and detailed charter of TBWG was developed
■ Chair from the Parties and Vice Chair from Central Team
■ TBWG members: 3 from each Party and 6 from Central Team
– TBWG Main Objectives: Develop a Coordinated Blanket Test Program and
address the Interface between machine and the blanket modules
– During EDA, TBWG addressed both:
■ the breeding blanket for the ITER extended performance phase
■ DEMO-relevant breeding blanket concepts of the Parties, modules of which were
planned to be installed in the ITER machine for testing: developed GDRD and
specified interfaces with ITER
– During EDA, the US made major contributions to testing strategy,
engineering scaling, test port, frame design, and machine interface
18
• The US was “out” during EDA Extension and ITER
Transitional Agreement (but TBWG continued)
• The TBWG was re-established in new conditions (6 partners) in 2003
• TBWG Scope of Activities:
A. Provide the design documentation for the assessment of TBMs
prepared by the Parties, integration of TBMs into the ITER machine
(including physical interfaces, auxiliaries, support facilities, machine
operation, safety, waste management, reliability and maintenance)
B. Promote cooperation among the ITER Parties’ TBMs
C. Verify integration of the TBMs in the safety and environmental
evaluations of each ITER candidate site
D. Further develop the coordinated blanket test program
• Reporting (elaborate and specific)
--
For Activities A, C and D: “report” to the Interim Project Leader
and the Preparatory Committee. “Inform” the PTs leaders
--
For Activity B: “report” to the PTs leaders
19
Current TBWG Effort, Port Allocation, and
Preferences of the Parties

Since TBWG was reactivated in October 2003,
several meetings have been held to:
1) discuss and agree on port allocation and concepts
to be tested,
2) plan for international collaboration, and
3) provide ITER with details impacting the ITER device
and plant (e.g. plasma exposure, off-normal events,
ancillary equipment).

There are 3 ports for testing
- There is a Port Master for each port

Five Working Subgroups were formed to examine
technical issues and coordinate among the parties
20
Blanket Concepts for ITER-TBM Selected by the
Various Parties
• Solid Breeders
– He/SB/Be/FS: All parties are strongly interested
– H2O/SB/Be/FS: Only Japan (some interest from China)
• Liquid Breeders
– He/LiPb/FS (Separately cooled): EU lead (one of two main
concepts for EU, interest from other parties)
– Dual Coolant (He/LiPb/FS with SiC): US lead, strong
interest from EU and other parties
– Li/V (Self-cooled): Russia is main advocate (but no
significant resources on R&D!)
– Molten Salts: US and Japanese Universities want the
option to decide later whether to test
– He/Li/FS: Korea’s proposal
21
Port Allocations for ITER TBM
Port A
Port B
Port C
He-Cer (1)
H2O-Cer
Li/V
He-Cer (2)
He-LiPb
Dual Coolant (LiPb or
Molten Salt)
Port Master A:
Boccaccini
Port Master B: Enoeda Port Master C: Kirillov
Working Group*
2 Working Groups*
Cer/He
H2O-Cer He-LiPb
(include DC)
2 Working Groups*
Li/V
Molten Salt
*Members
nominated
eachinterested
interested party
party (not
members
of TBWG).
*Members
nominated
byby
each
(notnecessarily
necessarily
members
of TBWG).
22
IV.
US Strategy for ITER TBM and
Brief Description of Effort and
Selected Concepts
23
Redirecting US Plasma Chamber Systems Effort
to support ITER
 With the US rejoining ITER, the Blanket/Chamber community concluded
that it is very important for the US to participate in the ITER Test Blanket
Module (TBM) Program (March 2003).
 Extensive deliberations have occurred in the US since March 2003 among
the community, DOE and VLT.
 Reached consensus on a general framework for the direction of activities
in the US Chamber/Blanket Program:
 Provide fusion nuclear technology (FNT) support for the basic ITER
device as needed
 Participate in ITER TBM program and redirect good part of resources
toward R&D for TBM
 Encourage partners in international collaborations, such as JUPITERII to focus more on ITER TBM
 Important work has been carried out to implement the strategy.
• A study of ITER TBM issues and US options was initiated
• Some R&D was initiated
• Rejoined TBWG, strong participation
• The US interacted with all the other 5 parties to identify areas of
collaboration
24
Highlights of US Strategy for ITER TBM
(Evolved over the past year by the community, DOE and VLT)
 The US will seek to maximize international collaboration. There
is a need for all parties to collaborate, and to possibly consider
a more integrated plan among the ITER parties for carrying out
the R&D and construction of the test modules.
 ITER TBM should be viewed as a collaborative activity among
the VLT program elements. While the Blanket/Chamber
Program provides the lead role for ITER TBM, major
contributions from other programs (e.g., Materials, Safety,
PFC) are essential.
 The US community has now reached consensus on preferred
options for ITER TBM (see separate slide), following
assessment of new technical results obtained over the past
few years.
25
What should the TWO US Blanket Options be for
ITER TBM?
• This has been a central question for the US community since March 2003. A
study was initiated to select the two blanket options for the US ITER TBM in
light of new R&D results from the US and world programs over the past
decade.
• Key conclusions reached early in the study:
- Selection between solid and liquid breeders can not be made prior to fusion testing in ITER.
- All Liquid Breeder Options have serious feasibility (“Go/No-Go”) issues. Need assessment.
- Solid breeders are accepted by all parties.
• For the past year, the study has focused mostly on assessment of the critical
feasibility issues for liquid breeder concepts. Examples of issues are MHD
insulators, MHD effects on heat transfer, tritium permeation, corrosion, SiC
insert viability, and compatibility.
• The study has been led by the Plasma Chamber community with strong
participation of the Materials, Safety and PFC Programs. Many international
“Experts” in key areas participated in several meetings and provided important
input.
26
US Selected Options for ITER TBM
The initial conclusion of the US community, based on the results of the
technical assessment to date, is to select two blanket concepts for the US
ITER-TBM with the following emphases:
•
•
Select a helium-cooled solid breeder concept with ferritic steel structure and
neutron multiplier, but without an independent TBM (i.e. support EU and Japan
using their designs and their TBM structure and ancillary equipment). Contribute
only unit cell and sub-module test articles that focus on particular technical
issues of unique US expertise and of interest to all parties. (All ITER Parties have
this concept as one of their favored options.)
Focus on testing Dual-Coolant liquid breeder blanket concepts with potential for
self-cooling. Develop and design TBM with flexibility to test one or both of these
two options (decision in 1-3 years):
–
a helium-cooled ferritic structure with self-cooled LiPb breeder zone that
uses SiC insert as MHD and thermal insulator (insulator requirements in
dual-coolant concepts are less demanding than those for self-cooled
concepts);
–
a helium-cooled ferritic structure with low melting-point molten salt.
Because of the low electrical and thermal conductivity of molten salts, no
insulators are needed.
(The key issues for molten salt are being addressed under JUPITER-II and no
additional work is planned under ITER-TBM.)
27
Helium-Cooled Pebble Breeder Concept for EU
Helium-cooled stiffening grid
Breeder unit
FW channel
- The US can provide small breeder units “inside” the EU SB structure.
- US Issues: Tritium Release and Thermomechanical Interactions
28
EU – The Helium-Cooled Lead Lithium (HCLL)
DEMO
Blanket
Concept
Module box
(container & surface
heat flux extraction)
Breeder cooling
unit (heat extraction
from PbLi)
[18-54]
mm/s
[0.5-1.5]
mm/s
Stiffening structure
(resistance to accidental in-box
pressurization i.e He leakage)
He collector system
(back)
HCLL PbLi flow scheme
29
RAFS/He/Pb-17Li Dual Coolant Blanket Concept
 The reason fusion pursued high temperature
materials is for high coolant temperature for
efficient power conversion.
 MHD effects in high-velocity channel flows
leads to very high primary stresses that
materials must accommodate.
 IDEA – the Dual Coolant Concept:
use the poor thermal and electrical
conductivity of SiC as an advantage.
– Cool structure with He so LM velocity
can be low and LM bulk temperature
can be higher than the wall temperature.
– Use a SiC insert to electrically and
thermally insulate the LM from the wall.
– Result: potential for high bulk
temperature with lower MHD pressure
drop using RAFS.
30
Close-up of a Pb-17Li Breeder Channel
Self-Cooled
Breeder Zone
(from ARIES-ST)
Dimensions in mm
31
Structure, Insert, and Breeder Temperatures
FS grid
Temperature
drop across the
FCI is 175 C
32
Dominant Issues for Dual Coolant Blankets:
FCI Properties and Failures
A) Electrical and thermal conductivity of the SiC/SiC perpendicular to the
wall should be as low as possible to avoid velocity profiles with sidelayer jets and excess heat transfer to the He-cooled structure.
B) The inserts have to be compatible with Pb-17Li at temperatures up to
700-800°C.
C) Liquid metal must not “soak” into pores of the composite in order to
avoid increased electrical conductivity and high tritium retention. In
general “sealing layers” are required on all surfaces of the inserts.
- Even if the change in conductivity results in modest increase in
pressure drop, it could seriously affect flow balance.
D) There are minimum primary stresses in the inserts. However,
secondary stresses caused by temperature gradients must not
endanger the integrity under high neutron fluence.
E) The insert shapes must be fabricable and affordable.
33
V.
Programmatic Issues Requiring DOE
and US ITER Management Attention
34
V.
•
Programmatic Issues Requiring DOE and
US ITER Management Attention
Include ITER-TBM in US ITER Organization
– a “box/area” for TBM in the Organizational Chart
– budget from DOE can remain separate from ITER construction funds
•
Recognize ITER-TBM as a US Program and organize it as a community effort
– Led by Plasma Chamber
but with major contributions from Materials Program and significant contributions
from PFC, Safety, and Tritium Programs
– Form Steering Committee with members from TBWG , Plasma Chamber, Materials,
PFC, Safety, etc.
•
Resources Needed
– Technical expertise is available
– Required financial resources will be estimated over the next few months, but
preliminary estimates show they are modest, not much beyond present budgets
(mostly “refocus” and “rebalance” with modest increases, if possible)
– Resources consist of:
a) annual R&D: starting now; already started under Plasma Chamber with some support from
Materials, Safety , and PFC. Need to do more under other programs.
– Need a lot more from the Material Program in particular (discussions to refocus parts of Materials to
serve ITER-TBM needs is underway)
b) cost of constructing Test Articles (to be inserted in ITER): needed 7 years from now . It is
modest and can be adjusted based on the role US wants to play.
35
V.
Programmatic Issues Requiring DOE and
US ITER Management Attention (Cont’d)
• Formal International Agreement for ITER TBM
– Letter from TBWG to ITER Interim Project Director
and ITER PT Leaders (7/22/2004):
“ It has become abundantly clear that planning for
and conducting the ITER TBM program requires a
structured framework among the Parties either as a
new arrangement under the ITER Joint
Implementation Agreement or even as part of
it……..”
– Recommend the US support this
36