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HIGH TEMPERATURE GAS-COOLED
REACTOR FOR HEAT SUPPLY AS A
NATURALLY SAFE AND INNOVATIVE
NUCLEAR SYSTEM
CIGS 3rd International Symposium on Global Warming
December 11, 2013
Masuro OGAWA
Nuclear Hydrogen and Heat Application Research Center Japan Atomic Energy Agency (JAEA)
CONTENTS
1. Outline of HTGR (High Temperature Gas-cooled Reactor)
2. Reduction CO2 with Heat
Supply from HTGR
3. Solutions for Social Issues
4. Perspective of HTGR
5. Concluding Remarks
1. OUTLINE OF HTGR
WHAT CAN HTGR DO?
( HTGR: High Temperature Gas-cooled Reactor)
3
HTGR can supply high-temperature heat
at 950oC
Heat supply to various
industry/transportation
fields
High thermal efficiency
due to high temperature
0 500 1000 1500
Reactor outlet temperature TH (℃)
0.5
0
1.0
TL : Low side temperature (25oC)
Td : Temperature with ⊿G = 0 (4436oC)
H2 production : η =TH - TL
TH
TH - TL
TH
Td
Td - TL
Td
Td - TL
Power generation
(Carnot cycle)
TH - TL
TH
TH - TL
TH
81%
950oC76%
66%
61%
52%
48%500oC
300oC
LWRHeat→Electricity→H2
33% 70-90%
23%
31%~
HTGR
Heat→H2
Theoreticalefficiencyof IS process
40%
~
67%
50%
η =
Th
eo
retica
l e
ffic
ien
cy η
0 200 400 600 800 1000 1200 1400 1600Temperature (oC)
Glass production
Cement production
Steel productionDirect reduced iron Blast furnace
High efficient GT power production
Thermochemical IS process
H2 production from naphthaH2 production from steam methane reforming
DME/Methanol synthesis
Ethylene production from naphtha
Ethylene production from ethane
Styrene production from ethyl benzene
City gas production
Oil refinery
Heavy oil desulfurization
Pulp, paper production
Urea synthesis
Desalination
District heating
HTGR
FBR
LWR
4
WHAT IS HTGR DIFFERENT
FROM EXISTING LWR?
5
Ceramic fuel-cladding, graphite-moderated
and helium gas-cooled HTGR
Typical specification
Coolant temperature : 950 oC
Thermal Output : Max. 600MW
Heat utilization ratio : 70-80%
Gas turbine
District heating
Seawater desalination
Hydrogen production
Process heat
Electricity generation
Agriculture, Aquatic product industry
950 oC
Reactor
500 oC
Waste heat
~200 oC
HTGR
6
HTGR LWR
Coolant Helium gas
• No phase change
• Chemically inert
• No activation
Light water
Fuel coating Ceramics • No melting Metal (Zirconium)
Moderator Graphite • No evaporation Light water
Reactor thermal power Compact (~600MW) • Collocation with demand site Large (~4500MW)
HOW DOES HTGR MAKE
PROGRESS IN TECHNOLOGY?
7
Previous abundant knowledge and experiences
GCR AGR HTGR VHTR
Fuel Natural
uranium
Enriched
uranium ← ←
Fuel coating Metallic
material ← Ceramics ←
Coolant
/Temperature CO2/400oC CO2/600oC~ He/700oC~ He/950oC~
Pressure
vessel Steel, PCRV PCRV
PCRV,
Steel (Small-size)
Steel
(Small-size)
Progress
Commercial
operation (UK, France, Italy,
Japan, etc.; 37 units)
Commercial
operation
(UK ;14 units)
Experimental reactor
(UK,US, Germany; 1 unit/country)
Prototype reactor
(US, Germany; 1 unit/country)
Test reactor (China; 1 unit),
Demonstration reactor (China; 2 units)
Experimental test
reactor HTTR
(Only exist
in Japan)
• Development of GCR starts from the first days of that of nuclear power, i.e. at the same
time as development of LWR.
• Direction of GCR commercialization with high coolant temperature is summarized to Gen-
IV VHTR as shown in the following table (Next generation LWR is classified to Gen-IV)
• Japan has constructed and been operating VHTR experimental test reactor, HTTR based
on extensive technical knowledge obtained in the developments of GCR, AGR, HTGR,
and accidents of TMI and Chernobyl.
8
0.92 mm
UO2
Ceramic
cladding of fuel
Isotropic
Graphite
Heat-resistant
Superalloy
Quartet coating technology for cladding to have heat resistance
Confinement of radioactive materials for about
three times longer than of LWR
Temperatures up to 1600 oC
Hot-pressurizing technology for graphite to have isotropy
High strength, thermal conductivity, and
radioactive-resistance
Temperatures up to 2400 oC
Fortifying technology for metal to have heat resistance
High-temp. structural technology for components
Helium-handling technology for coolant to reduce leakage
(Chemical, mechanical and nuclear-physical stability)
Utilization of heat at high temperature of 950 oC
Japan’s Cutting-edge Homegrown Technologies
IHX
Reactor
HTTR
(30MW, 950 oC)
HTGR test reactor of
JAEA at Oarai Japan
9
Prismatic HTTR reactor core and fuel
Reactor
Fuel
element
Primary
cooling pipe
Reactor pressure vessel
580mm
Fuel element Fuel rod
34mm
Graphite sleeve
Fuel compact
Plug
Fuel compact
26mm
39mm
Coated fuel
particle
Fuel kernel,600μm
920μm
Low density porous PyC
SiC
High density inner PyC
High density outer PyC
Fuel
rod
10
Remaining development issues in HTGR
11
Establishment of HTGR technologies - Demonstration for performance and reliability of key technologies
e.g. fuel, graphite moderator, Heat-resistant alloy, high
temperature structural design code, etc., using the HTTR
Construction of lead plant and commercial plant (Dec. 2010)
- Establishment of regulatory guidance for HTGR
Design guideline for high temperature component
Design guideline for graphite component
Safety design standards
- Development of material database including strength test and irradiation
test for life extension
Consensus-building toward the HTGR deployment in reactor site
PRESENT STATUS
IN THE WORLD?
12
National projects in the world
13
US; NGNP project 2012:Final design
started
Kazakhstan: KHTR project South Korea:NHDD project
750oC Cogeneration
発電
HTGR
Heat supply
Power generation
HTGR
H2 production
950oC H2 production
750oC
Power
generation
HTGR
H2 production
District heating
Power generation
2012:Concept study started
China: HTR-PM
750oC Power generation
2017:Construction of demonstration plant will be completed
2013:Feasibility study in preparation
US NGNP project
<Electric utility>
・Entergy
<Chemical company>
・Dow(The Dow Chemical Company)
<Petrochemical company>
・ConocoPhillips
・Petroleum Technology Alliance Canada (PTAC)
<Graphite manufacturer>
・GrafTech International Ltd.
・SGL Group ・Mersen
・Toyo Tanso Co., Ltd.
<Reactor vendors>
・AREVA ・Ultra Safe Nuclear
・Westinghouse
<Consulting company>
・Technology Insights ・SRS
・Advanced Research Center
South Korea NHDD project
<Electric utility>
・KHNP
・KEPCO
<Steel making company> <Petrochemical company>
・POSCO ・SK ENERGY
・GS Caltex
<Construction company> <Pump manufacturer>
・GS construction ・KNF
・Hyundai E&C
<Automobile company>
・Hyundai Motors
<Heavy Industry> <Electronics>
・Doosan Heavy Industry ・SUMSUNG
・STX Heavy Industry
<Research institute>
・KAERI
Industrial Alliances for HTGR in US and Korea
14
2. REDUCTION OF CO2 WITH
HEAT SUPPLY FROM HTGR
15
Concrete solution for reduction of CO2 emission
Vehicle 17%
Residential 13%
Steelmaking 13%
Chemical, petroleum
Others 23%
Power
generation 26%
Heat
57%
Elect
ricity
43%
Fossil
fuel
Nuclear
Issue: Reduction of
CO2 emissions in
heat utilization field
Solution: Heat supply from HTGR
Thermal power 600 MW
Outlet temp. 950℃
Coolant Helium
Cladding of fuel Ceramics
Moderator Graphite
1.19 billion ton CO2
(2010)
Natural energy
Natural
resources
Energy
Media
CO2 emissions
Heat demand in plants (MW) 27,000
Number of HTGRs 55
CO2 emissions reduction (%) 5
Chemical and petroleum plants
High temp. heat
Fuel cell vehicle
Number of vehicles (million) 75
Number of HTGRs 130
CO2 emissions reduction(%) 16
H2
Iron
ore
H2
Crude steel
(million t/y) 110
Number of
HTGRs 85
CO2 emissions
reduction (%) 9
Steelmaking Steam (c.a. 540oC) (~950oC)
Fuel
Heat
source
Reducing
substance
H2
30%
One HTGR (600MW) reduces
c.a. 0.1% of CO2 emissions
8%
16
3. SOLUTIONS FOR SOCIAL
ISSUES
WHAT WILL HAPPEN IN HTGR AT
THE FUKUSHIMA ACCIDENT?
17
Temp.
(oC)
Flow
rate
(%)
Time (hr)
Circulators trip
Coolant flow rate in the core
Reactor power
Fuel temperature
: Analysis: Experiment
Power
(%)
Temp. limit; 1600oC
Reactor inherently shut down
without control rod insertion
Decay heat removal
occurs naturally even if
normal heat transport
systems are not available
HTTR can intrinsically
shutdown reactor
• Initial reactor power
30%(9MW)
• Stop all circulators
• Without scram
• Operation of vessel
cooling system maintained
HTTR test result
TEPCO Fukushima
NPP accident
Earthquake
Control rod insertion
Reactor scram
Tsunami
Loss of offsite power
Loss of function for
decay heat removal,
core heat up,
core melt
H2 explosion
Release of
radioactive material
HTTR test condition (On December 12, 2010)
Vessel cooling system
Gas circulator Thermal
radiation
Natural convection
Control rod
Helium
Water
Dissipated to air
HTTR
- HTTR Can Intrinsically Shutdown with the Case
Equivalent to TEPCO Fukushima Accident-
18
Issue: Obtain consent of risk concept from public who concerns the following
- Even a small probability of occurrence such as once in 1 million reactor years, there is
no guarantee that it will not occur tomorrow.
- For events that lead to very large consequence, the event shall be evaluated only the
impact of the consequence instead of evaluation in risk
(Risk) = (Occurrence probability) x (Consequence of the event)
Safety objective “Protect people and the environment from harmful effects of ionizing
radiation” must be met in the layer of consequence mitigation. The degree of attainment
would be evaluated by risk assessment (in review). “Probability of occurrence for the accident which results in Cs-137 release of 100 TBq or larger
should be reduced to the value lower than 10-6/reactor year”
Defense in depth: Having provisions responding to the event progression based on the
assumption of the failure in the former layer.
1. Prevention of accident (occurrence, progression), if failed,
2. Mitigation of consequences,
3. Emergency planning (Evacuation, etc.)
If mitigation of consequence failed, evacuation is required. What if evacuation failed ?
For that reasons, mitigation of consequence must accomplished successfully
(1) Safety
19
Reactor can intrinsically secure safety by mitigating physical events to lose confinement
function only with physical phenomena without reliance on backup systems
Issues accompanied by risk concept and evacuation can be solved
20
Solution: Consequence Mitigation
by Natural Phenomena
Fission
product
Diffusion
Physical events to lose
confinement function
Sublimation
Corrosion
Containment Vessel
Reactor
Pressure
Vessel
Cause events
Core
Heat-up
Cladding
oxidation
by air
Counter physical
phenomena
CO
explosion
Doppler effect
Thermal radiation,
Natural convection
and so on
Oxide layer
formation
CO oxidation
Cladding
Attain
stable
state
Retain
fission
products
within
cladding
Rupture Uranium
Confinement
Core
Reactor
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
1.E+07
1.E+08
1.E+09
1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07
Years
Ra
dio
toxi
city
[S
v]
102 104 106102
104
106
108
(pe
r 1
ton
of
fue
l)
LWR Spent Fuel
High Level Waste
After Transmutation
HTGR
Spent Fuel
High Level Waste
Issue:Reduction of Radiotoxicity in Radioactive Waste
Solution:Utilization of Thorium
Partitioning of U and Pu
Partitioning of MA
(2) Radioactive Waste Reduction
Fuel composition
・ LWR
U-235 : 4.5%
U-238 : 95.5%
・ HTGR
U-235 : 10%
Th-232 : 90%
Remarks
• Enrichment of uranium
and reprocessing of Th
are needed.
• LWR can also use Th.
U235: 4.5%
U238: 95.5%
U235 : 10%
Th232 : 90%
Elapsed
21
Operation and Maintenance
0
50
100
150
200
LWR HTTR
GBq/yr
≒0
175Liquid
0
5
10
15
20
LWR HTTR
GBq/yr 12
≒0
Gaseous
Less Low-level
radioactive waste
Cooled by natural
circulation of air
Spent fuel
Easy management of spent fuel
Shallow ground disposal for spent graphite
Spent graphite quantity:
~3000m3/unit, 60 years
(1/500 of baseball dome volume
(1.58M m3))
(http://www.sapporo-dome.co.jp)
Unit:[t-U(Enriched)/GWe]
Less spent fuel per unit power generation rate
(Depends on enrichment, efficiency)
1130
348
0
500
1000
1500
LWR GTHTR300
22
Low worker dose
10
5
0LWR
BWR(2005)PWR(2005)
HTTR
軽水炉の1/600
1~15.5
1~6.4
0.0016
被ばく線量
(人Sv/年)
1/600 of
LWR W
ork
er
dose (
man S
v/y
)
Power generation cost LWR : 5.3 Yen/kWh
HTGR : 4.2 Yen/kWh (HTGR 1 unit ( =4 modules) )
For 100MW electric power,
LWR : 9.7 Yen/kWh
HTGR : 5.3 Yen/kWh
In spite of
• High fuel enrichment,
• Multi-layer coating of fuel,
• Heat resistant alloy utilization,
compelling economics can be achieved
because of
• High electricity generation efficiency
• Simplified safety system
• Easy maintenance and operation
• Shop fabrication and preassembly
0
2
4
6
8
10
12
14
0 200 400 600 800 1000 1200 1400
HTGR
LWR
Po
wer
gen
era
tio
n c
ost
(Yen
/kW
h)
Electric power (MWe)
(3) Economy
Ref: M. Takei, et al., Economical Evaluation on Gas Turbine
High Temperature Reactor 300 (GTHTR300), Trans. At.
Energy Soc. Japan, 5(2), pp.109-117 (2006).
GTHTR300 Thermal/Electric Power
:600/275MW
Reactor outlet temp.
:850oC HX vessel
Recuperator PCS vessel
Compressor Generator
Turbine
Core
Reactor
Precooler
23
Issue: In general, as the power density becomes lower the plant economic get worse
Reactor and primary system
Reactor
(1.8)
Building (Reactor & turbine buildings, others)(25.6)
I&C, electric equipment(10.7)
Turbine, generator (11.5)
Reactor & station auxiliary system (13.0)
Primary system (9.2)
Condensate, feed water,
turbine auxiliary systems, Others
(13.1)
Others
(1.5)
Reactor
control system
(3.9)
Reactor protection
system
(4.0)
Construction cost*1 [Unit %]
HTGR with low power density core can achieve compelling economics due to
the following reasons
• Reactor cost only responsible for 2% of plant cost
• Core power density of HTGR is 1/10 of that of LWR • Increase in portion of reactor cost from 2% to 20% (x10) results in increase in
plant cost only by 18%.
• The 18% cost increase can be canceled out by advantages in HTGR.
100%
0
118%
Reactor
cost
(ca.2%)
LWR HTGR
Construction cost
x 10
20%
Bird’s eye view of PWR (2 modules)
PWR 1 unit
Ref: *1 Private communication, *2 JAIF report, 1992;.
*3ORNL_sub_86-86004_7、Energy economic data base(EEBD) program phase VIII update(1986) BWR supplement 24
Rad waste
system,
Fuel
handling
(5.7)
Solution; HTGR can be economically competitive because of the superior
characteristics and the low ratio of reactor cost to plant cost
★Total building inventory: 674,000 m3
24 m
47 m
119 m
11 m
A
93.7 m
109.2 m
84.0 m
★Total building inventory:533,000 m3
80% of LWR’s building inventory
Turbine building A-A cross section
The Foot Print of HTGR
Ref: X. Yan, et al., Nuclear Eng. Design., 226, p351-373 (2003) Ref: Figure cited from application for establishment permit of Kasiwazaki-
kariwa nuclear power plant unit No.3 of TEPCO
GTHTR300 (275MWe x 4 modules ) )
LWR (1100MWe )
45 m
68.5 m
80 m
53 m A 22 m
76 m
Reactor building Turbine building BWR-5
HTGR ( 1100MWe )
25
Equivalent power output
4. PERSPECTIVE OF HTGR
26
27
中間熱交換器
原子炉
ガスタービン
高温ガス炉
水素製造プラント熱化学法ISプロセス
Heat supply for industrial
demand
No core melt
Economically competitive
Reduce radio toxicity in radioactive waste on the
order of hundred years by utilizing Thorium
(Separation of spent fuel is required.
Residual fuel after separation will be recycled)
Maintain sustainability using uranium from
seawater
(Recycling for nuclear fuel supply is unnecessary)
Achievement of natural-safety
Green fuel;H2 production Corresponding to temporal storage by inert matrix fuel.
Reduce the amount of spent fuel per produced electricity by
1/3 due to high burnup.
Incinerate surplus plutonium.
HTTR
Lead plant
Commercial plant
Establishment of most of the HTGR technologies
Naturally Safe and Innovative HTGR
Toyo Tanso
Receive a contract for
core components
of HTR-PM in China
Mitsubishi Heavy Industry
Conduct conceptual study for
a commercial HTGR plant MHR.
Propose construction of
lead plant. Make a contribution
to promoting commercial
deployment of HTGR by own technology.
M. Toyama (MHI), et al., ,” Expectations to HTGR”, HTR2012, Tokyo Japan.
NFI
Developed coated fuel particle
fuel for higher burn-up condition
Fuel compacts are currently
under irradiation (100GWd/t)
Fuel compacts for irradiation test
JAEA Typical HTGR designs
(GTHTR300, GTHTR300H, and so on.)
Power : 600MW
Hydrogen : 51t/day
Electricity : 200MW
Temperature : 950oC
Burnup : 120GWd/t 250μm
IG-110
GTHTR300H
Present Status on National Activities
28
5. CONCLUDING REMARKS
HTGR is a Gen-IV and a small-sized reactor up to
600MW for heat supply such as hydrogen, process
heat, and steam.
HTGR technologies have been almost confirmed in
HTTR and lifetime verification remains. Technologies
of hydrogen production should be demonstrated.
HTGR can solve issues such as safety, reduction of
CO2 and radioactive waste in environmental
protection, economy and so on.
29
THANK YOU FOR YOUR ATTENTION!
HTTR
30