Gas Cooled Fast Reactor

13th GIF-IAEA Interface MeetingIAEA Headquarters, Vienna. 18-19 March 2019

Branislav Hatalapresented by Boris Kvizda

VUJE, a.s., Slovak Republic

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GFR Reference concept

The GFR system is a high-temperature helium-cooled fast-spectrum reactor with a closed fuel cycle.

The reference design for GFR is 2 400 MWth

The high outlet temperature of the helium coolant enables to deliver electricity, hydrogen, or process heat with high conversion efficiency

As a one of fast reactor would produce heat about 850°C, which will be able to chemically produce hydrogen

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Gas-cooled Fast Reactor

The produced heat (2 400 MWth) will be converted into electricity in the indirect combined cyclewith three gas turbines and one steam turbine.

- Primary/secondary arrangement: 3 x 800 MWth (IHX-blower unit)gas turbo-machineries (auxiliary alternators: 3 x 130 MWe)

- Tertiary: 1 steam turbine (main alternator 730 MWe)- Efficiency (~ 45%) ,

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Neutronic quasi-transparency Gas coolants generally allow a harder neutron spectrum,which increases the breeding potential of the reactor.

Simple in-service inspection of the primary system and internal vessel components because of the translucent nature of the coolant.

Helium is chemically inert no corrosion products in the primary system are expected.

No change in phase of the gas coolant.

The coolant does not become activated by irradiation.

No decommissioning issues associated with the coolant.

Helium coolant can be operated under very high temperatures no disassociation of Helium allowing very high system efficiencies.(CO2 disassociates ~ 800 °C)

Helium Coolant - Positive features

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Gas-cooled Fast Reactor

GFR primary system overall view

The cylindrical vessel with upper and lower spherical parts contains the core and internal cylindrical shell which separatesthe cold zone from the hot zone.

Three main heat exchangerswith blowers,

Three Decay Heat Removal loops

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Gas-cooled Fast Reactor

The whole primary system is enclosed in a small pressure guard containment.

1 - vessel 2 - three Main Heat Exchangers 3 - three Decay Heat Removal loops 4 - six gas reservoirs

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The main parameters of the GFR system

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Gas-cooled Fast Reactor

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GFR - Decay Heat Removal System

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Gas-cooled Fast ReactorALLEGRO Project

Technology demonstration as a first gas-cooled fast reactor

ALLEGRO GFR 2400

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The ultimate objectives of ALLEGRO

Demonstration of the GFR gen. IV concept, (alternative technology to the reactor cooled by molten sodium)

-demonstration of the technological feasibility,helium cooling and high temperature core (inovative fuel)

- demonstration of the breeding capacity,- demonstration of the ability of transmutation of actinides.

Demonstration of heat production at industrial and economic conditionsAs a one of fast reactor would produce heat about 850°C, which will be able to chemically produce hydrogen.High temperature heat could be used also for technological purposes.

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ALLEGRO reactor

Technology demonstration as a first gas-cooled fast reactor

ALLEGRO GFR 2400

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ALLEGRO reactor

DHR Blower

3 x DHR HX

DHR Valve

Primary Blower

PrimaryValve

Water Pump

Pressurizer

Aero

Core

260 °C

7 MPa

197 °C

127 °C

6.5 MPa

He

Water

75 MWth

Water pool

2 x Primary Circuits

He

Pony motorNitrogen accumulators (3 x 200m3)

Guard vessel

Air Blower

1MPa

6.5 MPa

56.45 kg/s

2 x Secondary Circuits

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The guard vessel has two main safety functions: A contamination barrier function

Maintaining of the back-up pressure in the primary system during LOCAs⇒Helium leaktightness for the guard vessel is required.

Inner diameter: 18mTotal height: ~ 32mThickness: 40 mmPressure resistance limit value: 10 bars

ALLEGRO reactor

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ALLEGRO core

MOX Core

Ceramic Core

Core power 75 MWth

Coolant pressure 7 MPa

Primary mass flow rate

53 kg/s 36 kg/s

Core inlet temperature

260 °C 400 °C

Core outlet temperature

560 °C 850 °C

The reactor shall be operated with two different cores:

- The starting core will serve to test the operation of the gas cooled fast reactor with well established fuel.

- The second core using the ceramic fuel will serve for testing the new fuel design.

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GFR SYSTEM RESEARCH PROJECTS

GFR System Arrangement Phase II has been signed by :Euratom,CEA – FranceJapan Atomic Egency Agency - Japan

Conceptual Design and Safety (existing project)EURATOM, France

Fuel and core materials (provisional project)EURATOM, France, Japan

GFR Technology Project (proposed project)

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Status of GFR reference documents

Risk and Safety Assessment White Papercompleted (august 2016)

Safety Assessmentpending RSWG review new version June 2018

Safety Design CriteriaDraft February 2018

Safety Design Guideline

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V4G4 Center of ExcellenceALLEGRO Project

VUJE, a s.

UJV Řež, a.s.

Hungarian Academy of SciencesCentre for Energy Research

National Centre for Nuclear Research Poland

Associated members

Allegro Project – Preparatory Phase is carried out by the V4G4 Centre of Excellence

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Aim of „V4G4 Center of Excellence“

- investigating crucial aspects, in particular regarding safety, and generating experimental results for the development of Generation 4 nuclear reactors, especially for the innovative concept GFR (Gas Cooled Fast Reactors) for which a demonstrator, ALLEGRO, will be built and operate in the V4 region

- promoting and popularizing the potential, perspectives, technical, political and environmental issues related to Generation 4 nuclear reactors,

- contributing to the preservation of nuclear qualifications by involving young scientists and engineers into its challenging research and development activities,

- facilitating the integration of nuclear research in Central Europe.

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ALLEGRO strategy

A new strategy for developing the ALLEGRO reactor:• Feasibility and optimization of the first core

aimed at maintaining the ALLEGRO coolable in passive mode in protected depressurized scenarios;

• Feasibility and optimization of the appropriate backup pressure in the guard vessel for the most critical scenarios;especially in LOCA aggravated with SBO in passive mode;

• Desing and optimization of the DHR system

Use UO2 pellets in AIM1 cladding instead of MOX pellets in AIM1.• Analyses on the core optimization- pellet diameter increasing, - number of fuel assemblies increasing, - core height increasing

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Optimization of N2 injectionduring LOCA + SBO

- 10 inch LOCA + Total Station Blackout- Cold duct No. 1 (leak to the Guard vessel)- Core power 75 MW

ACCU:- 3 x 200 m3 N2 accumulators- 3 x 50 m3 He accumulators (option)- Initial pressure: 6.5 MPa- Initial temperature: 50 °C

Guard vessel:- Free volume: 2600 m3

- Initial pressure: 0.1 MPa- Initial temperature.: 50 °C

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Optimization of N2 injectionduring LOCA + SBO

No. Description Note / Change to the above one

1. Reference case 3 x 200 m3 N2 accumulators

2. 1x N2 ACCU ESFAS setpoint change Primary pressure < 6.0 MPa + DHR blower speed < 80% after 10 s of start-up

3. N2 ACCU not waiting for DHR to be fully opened Instant N2 injection after ESFAS

4. Resistance of the stopped DHR blowers Ksi of the non-rotating DHR blowers reduced to 1.0 (fwd), 1.5(rev)

5. Sensitivity on the proper N2 ACCU & He tanks volume

3 x He tanks added (Vol: 0, 50, 100, 150 m3)3 x N2 ACCUM (Vol: 100, 150, 200 m3)

- Primary pressure < 6.0 MPa- Primary pressure < 1.5 MPa

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Optimization of N2 injectionduring LOCA + SBO

1. Reference case

2. 1x N2 ACCUESFAS setpoint change

3. N2 ACCU not waiting for DHR loopsto be fully opened

4. Resistance of the stopped DHR blowers reduced

5b. N2 3 x 150 m3

He 3 x 50 m3

5d. N2 3 x 200 m3

He 3 x 50 m3

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ALLEGRO reference documents

ALLEGRO Design Specification

ALLEGRO Safety Requirements

ALLEGRO R&D Roadmap

ALLEGRO Design & Safety Roadmap

ALLEGRO V4G4 Concept Database

ALLEGRO Business Plan

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EUROPEAN PROJECTS on GFR

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

ALLIANCE ALLEGRO

GoFastR GFRGCFR GFR

VINCO ALLEGRO+HTR

GCFR - The Gas Cooled Fast Reactor Project (FP7) - research projectMarch 2005 - February 2009

GoFastR - European Gas Cooled Fast Reactor (FP7) - research on GFR conceptual designMarch 2010 - February 2013

ALLIANCE - ALLegro Implementing Advanced Nuclear Fuel Cycle (FP7) coordination and support action

Non-research activities in support of the implementationof the Strategic Research Agenda of Sustainable Nuclear Energy Technology Platform and safety of nuclear systems

October 2012 - September 2015VINCO - Visegrad Initiative for Nuclear Cooperation (Horizon 2020)

coordination and support action capacity building activities aiming at strengthening the coordinating role of the “V4G4 Centre of Excellence” and supporting its member organizations

September 2015 - August 2018

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Infrastructure S-ALLEGRO

Owner:

Research Centre Řež, Czech Republic

•Parameters

•primary loop 1•DHR loop 1•medium Helium•max. pressure 7 MPa •power 1 MW (electric power)•tout (model core) 850°C•flow rate (I. loop) 0,5 kg/s (Forced circulation)

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Infrastructure – STU Helium Loop

OwnerSlovak University of Technology in BratislavaFaculty of Mechanical Engineering

Parameters•Helium output temperature 400ºC to 520 ºC•Helium input temperature 150 ºC to 250 ºC•Helium operational pressure 3 MPa to 7 MPa•Installed input power 500 kW•Designed DHR heat power 220 kW

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Conclusions

The GFR concept is attractive as it avoids the coolant handling issues associated with liquid metal-cooled fast reactors:

• Helium chemically inert• Excellent nuclear stability avoids activation of the coolant• Transparent coolant permits simple inspection and repair

GFR offers a high temperature heat source for high efficiency electricity generation and high-quality process heat.

The main technical challenges lie in the development of a high-temperature, high-power density fuel and in the development of robust decay heat removal systems.

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VUJE, a.s.

Okružná 5918 64 TrnavaSlovak Republic

www.vuje.sk

Boris.Kvizda@vuje.sk

Thank you for your attention