Overview of High Temperature Gas-Cooled Reactors ... · and the Impact on Infrastructure Requirements ... Tomorrow’s Fuel Recyclers ... response plan needed since no need to evacuate

Overview of High Temperature Gas-Cooled

Reactors Technology

and the Impact on Infrastructure

Requirements

Frederik Reitsma Gas-Cooled Reactors Technology

Nuclear Power Technology Development Section

Division of Nuclear Power | Department of Nuclear Energy

INPRO Dialogue Forum: 26 – 29 August 2014

1 26-29 August 2014 INPRO Dialogue Forum 8

International Atomic Energy Agency

Contents

• Overview of HTGR

• A reminder of the scope of Infrastructure in the INPRO methodology

• Comments on Infrastructure Needs for HTGRs

– What may be different … if anything

26-29 August 2014 INPRO Dialogue Forum 8 2


HTGR / LWR COMPARISON Item HTGR LWR

Moderator Graphite Water

Coolant Helium Water

Avg coolant exit temp. 750° - 1000 °C 310°C

Structural material Graphite Steel

Fuel clad Graphite & silicon Zircaloy

Fuel UCO/ UO2 UO2

Fuel damage temperature >2000°C 1260°C

Power density, w/cc 6.5 58 - 105

Linear heat rate, kW/ft 1.6 19

Avg neutron energy, eV 0.22 0.17

Migration length, cms 57 6

26-29 August 2014 3 INPRO Dialogue Forum 8


Pebble type HTGRs

• Spherical graphite

fuel element with

coated particles

• Possibility of

continuous fuel

loading / shuffling

• Fuel loaded in

cavity to form a

pebble bed

26-29 August 2014 INPRO Dialogue Forum 8 4

1 mm

Pebble Bed Reactor (PBR)


Prismatic (block-type) HTGRs



Why HTGRs?

Significantly improved safety characteristics

No core meltdown or core damage

Can sustain full load rejection / station blackout conditions

No need for multiple layers / multiple trains of cooling capabilities

Simplified designs and few safety related systems

Higher efficiency than conventional nuclear plants

HTGR potential market considered today is small (but growing)

Smaller reactors lend themselves to distributed generation (advantages

relate to grid stability and transmission costs)

HTGRs offers high burnup (>80,000, up to 200,000 MWd/t proven)

Can contribute to the total energy market (cogeneration)



Inherent Safety Approach Ceramic fuel retains radioactive materials

up to ~2000˚C

Coated particles stable to beyond

maximum accident temperatures

Heat removed passively without

primary coolant

Fuel temperatures remain below design

limits during loss-of-cooling events

Centre Reflector Pebble Bed Side Reflector Core Barrel RPV RCCS Citadel

RadiationConduction

Conduction

Conduction

Convection

Radiation

Convection

Conduction

Radiation

Convection

Conduction

Convection

Radiation

Convection

Conduction

Radiation



Industrial Heat Requirements (why

HTGRs are promising)

HTGRs

SFRs

Today’s Power Plants

Tomorrow’s Fuel Recyclers

Tomorrow’s Industrial Energy



Infrastructure Needs of HTGRs


• Not to be confused with only the engineering

/ site infrastructure and equipment needs..

– Water supply, power supply

– Access roads, site security

– Component manufacturing

– Quality assurance

…. but include a much wider consideration


INPRO: Infrastructure Needs of

HTGRs


• Within the INPRO methodology, the term

infrastructure can be defined as the collection of

necessary capabilities of national institutions to

achieve long term sustainability of a nuclear power

programme in a given country.

– a reactor and related nuclear fuel cycle facilities are not

considered to be a part of a national infrastructure, albeit

that they influence the size of the necessary

infrastructure required

…. so the technology choice will only have an

indirect impact



Assessment relative to large LWRs ( “my own first thoughts”)


# Requirement Modular HTGR

UR1 Legal and Institutional

infrastructure

Similar.

CR1.1 Legal (Legal framework /

Nuclear law)

Guidance from IAEA and other international

organizations is focussed on LWRs

CR1.2 Institutions (Licensing)

Mixed view:

Less experience of licensing in the world for HTGRs

Much simpler design

CR1.2

Institutions (Emergency

preparedness and

response)

Mixed views: Many designs claims no emergency

response plan needed since no need to evacuate the

public. May not be acceptable to regulator and public

CR1.2 Institutions (Waste

management)

Larger volumes Higher burnup and much lower heat

load; Currently no proven industrial reprocessing or

waste minimization processes (lot of research only);

Coated particle fuel an ideal form for final disposal





UR2 Industrial and economic

infrastructure

Mixed – Large reactor but less safety systems;

CR2.1

Finance Smaller capital expenditure, promised shorter

construction time with associated financial benefits

Currently higher cost per MWe produced

CR2.2 Size of nuclear facility Modular so added as needed in case of smaller grids

Need all the infrastructure (independent on the size of

NPP)

CR2.3 Siting Same needs; Dry cooling a possibility and thus

additional sites may be considered

CR2.4

Support Infrastructure Same needs; but suppliers of technology and

technical support is limited

CR2.5 Added value Depends – cost of electricity generation today higher

than large LWRs

Co-generation; process heat and remote applications

may make it more attractive; GEN-IV system





UR3 Political Support and

Public Acceptance

Similar

Mixed views:

Inherent safety characteristics – no emergency response

plan needed since no need to evacuate the public;

no core meltdown possible;

presence of graphite and miss-information on graphite

fires

positive reactivity coefficient for steam ingress

(depending on the design)

UR4 Human resources

Similar

Knowhow required irrespective of technology and plant

size

# of people on site during construction (smaller plant) and

operation is less


Thank you!

Frederik Reitsma

Gas-Cooled Reactors Technology

Nuclear Power Technology

Development Section

Email: [email protected]

14 26-29 August 2014 INPRO Dialogue Forum 8


Reactor footprints …

15

• The Vogtle 3 and 4 Nuclear power plant USA

- 2 units = 2220 MWe

26-29 August 2014 INPRO Dialogue Forum 8



16

• The HTR-PM - (Two-reactor unit) = 210MWe




17

• 2 units = 2220 MWe : 16 units = 3360 MWe


Documents

Overview of High Temperature Gas-Cooled Reactors ... · and the Impact on Infrastructure Requirements ... Tomorrow’s Fuel Recyclers ... response plan needed since no need to evacuate