the ahtr for grid demands of the future - ee publishers · 2017. 12. 5. · the ahtr for grid...

The AHTR for Grid Demands of the Future

by Mmeli Fipaza, Eskom - Nuclear Engineering


• Enhanced Nuclear Safety

• Constructability and Modularity

• Flexibility of Utilization

• Scalability of Power

Drivers for Gen IV Reactors


• Power to be Available WiFi

• Electricity Grids Smaller and Smart

• C02 Reductions Mandatory

• Provide for Cogeneration Power Plants

• Surrogate for Intermittent Renewable

Futuristic Outlook


Challenges of Supply

Between the Poles – Blog http://geospatial.blogs.com/geospatial/2013/11/the-challenge-of-balancing-supply-and-demand-when-

intermittent-sources-exceed-20-of-total-power-dema.html


• When the PBMR was defined in the mid 1990s it was based on the German industrially demonstrated technology

• The PBMR approach was to avoid any fundamentally new technologies and to move directly to the “demonstration” reactor which would by essentially a first of class of the commercial design

• One of the key elements of the PBMR work was the confirmation that fuel to the required specification could be built locally at NECSA

• Many lessons were learned from the development of the design of the PBMR. Given the South African fuel performance and the technological advances since the original German work, there is great potential to build on the PBMR technology base to achieve higher safety and economic performance.

PBMR Background


Options for Development


Design a nuclear reactor for the grid demands of the future:

• Plant should fit various size grids

• Flexible to follow load changes

• Adaptable to various demand side requirements

• Simplified construction and maintenance

• Safe without engineered safety systems

• Economic – maximise efficiency, reduce costs

Options for Development

POWER SOURCE & BASE LOAD

BATTERY (Energy storage )

ENERGY TRANSFER( heat exchangers)

BOTTOM CYCLE(Steam turbine-generator )

CYCLE COOLING(Heat rejection)

GEN 2

GEN 1

MSHT tank

(680 oC )

MSLT tank

(280 oC)

HPC

LPC

T

CORE

1200 oC

Steam Super heater

Steam Generator

Pre-heater1

Deaerator

Co

nd

ense

r

Pre-heater

Feed water make-up tank

HP ST

Dry Cooling Tower (2 MW)

Re-heater

Res

idu

al h

eat

rem

ova

l Hx

& b

low

er

Super heated steam 530 to 600 oC

LP ST

Cooling tower water make-up tank

AHTR100: Process Diagram with Direct He Brayton Cycle, Molten Salt, Energy Storage, Steam Turbine and Dry Cooling Towers


Impact of a Molten Salt “Battery”

AHTR Operating Points Analyses


Concept Layout

Layout based on the kaXu Solar 01 CSP Plant with 100MWe and 3 hour molten salt storage

AHTR would be a 55MW average, with 120MW and 6-hour MS storage (customer dependent)

18m

Admin Bldg

Rx Bldg

MS Tanks

100m

Turbine BldgAir Cooled Cond.

200m 300m0m


Concept Guiding Principles– Combined cycle – use of He turbine to provide plant base-load,

bottoming HX-combination to provide secondary circuit load

following:

• Almost double efficiency

– Heat storage in secondary circuit for plant flexibility:

• Heat storage allows nominal 66% load following without

change in reactor power. Plant maintains full power output on

average – ideal for base and peak supply). Can be expanded.

• Modular for adapting to different grid demands


Concept Guiding Principles

Achieved through:

– Use of pre-stressed concrete pressure vessel at proven at 9MPa

– He up flow allows deep burn-up with once-through fuel cycle

– Modular power conversion unit, allows 5 day maintenance outage

– Online refueling – no refueling outage.

– Increase efficiency, reduce capital costs.

– Ideally suited for heat applications – Desalination, Hydrogen

production, supports reducing carbon emissions in the fossil

fuel industry.


Focus of the AHTR Work Since Inception (09/2016)

2016 focused on design concept:

1. System modelling

2. Physical design

3. Fuel Characterisation

4. Pre-stressed Concrete Pressure Vessel

development

5. Licensing Framework

6. Passive Cooling System

7. Cycle Optimisation

2017 will focus on material qualification and developing

design concept:

1. Material selection and qualification

2. Core physics design

3. Power Conversion Unit Design

4. Pressure Vessel Design

5. Control Systems Design

6. Heat pipes, Heat Exchangers and Turbine Design.

7. High Temperature Fuel performance analysis.

8. Manufacturing processes, including 3D printing.

9. Auxiliaries

10. Centre for High Performance Computing to

implement HTR codes


END

Thank you !!!!

Questions??

the ahtr for grid demands of the future - ee publishers · 2017. 12. 5. · the ahtr for grid...

Documents