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ENERGETIC AND ECONOMIC COST OF

NUCLEAR HEAT

IMPACT ON THE COST OF

DESALINATION

Document propriété du CEA – Reproduction et diffusion externes au

CEA soumises à l'autorisation de l'émetteur

GLOBAL' 2015 - 21st International

Conference & Exhibition « Nuclear Fuel

Cycle for a Low-Carbon Future »

Saied Dardour

CEA/DEN/DER/SESI/LEMS

Henri Safa

I2EN

OUTLINE

Introduction

Energetic cost of nuclear heat kW per MWth

– kWe of missed electricity production

– Additional kWth of core power required to keep electricity

production at its nominal value

Economic cost of nuclear heat $ per MWth

– Cost of heat to cost of electricity

MED vs. SWRO kWe per m3

– Who is the most energy-efficient?

Concluding remarks 7 MARS 2016 PAGE 2

INTRODUCTION

7 MARS 2016

| PAGE 3

CEA |

Document propriété du CEA – Reproduction et diffusion externes au CEA soumises à l'autorisation de l'émetteur

INTRODUCTION

Desalination

Desalination is the main technology used to

meet water scarcity.

Already 1.2 billion people, nearly a sixth of the

world's population, live in areas afflicted by

water scarcity, and that figure could grow to

1.8 billion by 2025 (a).

About two third of the worldwide installed

capacity is produced by Reverse Osmosis

(RO).

The remaining one third is produced mainly

by thermal desalination plants – Multi-Effect

Distillation (MED) and Multi-Stage Flash

(MSF) –, mostly in the Middle East.

7 MARS 2016 PAGE 4

MSF; 23%

MED; 8%

ED; 3%

RO; 63%

Hybrid; 1%

Other; 2%

75 million cubic meter per day (b)

(a) http://time.com/3625511/this-plant-in-dubai-makes-half-a-billion-gallons-of-fresh-water-a-day/

(b) GWI, IDA Desalination Yearbook 2012-2013.

INTRODUCTION

Seawater Reverse Osmosis

SWRO

7 MARS 2016 Illustration: degremont.co.za ERI DWEER

Specific power consumptions reported in literature: 2.7 to 7.0 kWeh.m-3

Energy recovery devices

INTRODUCTION

Multi-Stage Flash

MSF

The most commonly used thermal

desalination technology.

Seawater, preheated by external steam,

flashes in a series of stages of decreasing

pressures. Steam generated in each cell is

condensated to produce ultra pure water.

Typical characteristics:

Stages ~ 16 - 22 (a)

Top brine temperature ~ 90 - 120 °C (a)

Heat consumption ~ 55 - 80 kWhth.m-3 (b)

Electricity consumption ~ 2.5 - 5 kWhe.m-3 (c)

7 MARS 2016 PAGE 6

Illustration: H. Glade, Thermal Processes for Water Desalination, Sustainable Water

Technologies, 18-20 February 2013, Cairo, Egypt.

Illustration: http://wordpress.mrreid.org/2014/07/01/desalination/

MSF Recycle Distiller

Jebel Ali gas-fired M Station, United Arab Emirates.

(a) H. Glade, Thermal Processes for Water Desalination, Sustainable Water Technologies, 18-20

February 2013, Cairo, Egypt.

(b) Semiat, R., Energy issues in desalination processes, Environmental science & technology,

2008, vol. 42, no 22, p. 8193-8201.

(c) Al-Karaghouli, A., Kazmerski, L. L., Energy consumption and water production cost of

conventional and renewable-energy-powered desalination processes, Renewable and

Sustainable Energy Reviews, 2013, vol. 24, p. 343-356.

INTRODUCTION

Multi-Effect Distillation

MED

The oldest desalination technology.

Multiple spray-type seawater evaporators.

Steam condensates inside the tubes,

evaporating seawater. Steam produced in

each effect serves as a heat source for the

next effect.

Typical characteristics:

Stages ~ 4 - 12 (a)

Top brine temperature ~ 55 - 70 °C (a)

Heat consumption ~ 40 - 65 kWhth.m-3 (b)

Electricity consumption < 1.5 kWhe.m-3 (c)

7 MARS 2016 PAGE 7

Illustration: H. Glade, Thermal Processes for Water Desalination, Sustainable Water

Technologies, 18-20 February 2013, Cairo, Egypt.

MED with Thermal Vapour Compression (TVC)

Illustration: Tractebel Engineering

Taweelah, United Arab Emirates.

(a) H. Glade, Thermal Processes for Water Desalination, Sustainable Water Technologies, 18-20

February 2013, Cairo, Egypt.

(b) Semiat, R., Energy issues in desalination processes, Environmental science & technology,

2008, vol. 42, no 22, p. 8193-8201.

(c) SIDEM MED Brochure,

http://technomaps.veoliawatertechnologies.com/processes/lib/pdfs/productbrochures/key_technol

ogies/F733L0vn8nCHqOV2TEb2h77N.pdf

INTRODUCTION

kWthh.m-3

kWeh.m-3

Thermal desalination processes

Seawater reverse

osmosis

80

75

70

65

60

55

50

45

40

35

30

1 1,5 2 2,5 3 3,5 4 4,5 5 5,5 6 6,5 7

MED

MSF

SWRO

Electricity

Heat

Who is the most

energy-efficient?

Minimum set by thermodynamics

ENERGETIC COST OF NUCLEAR HEAT

7 MARS 2016

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CEA |



Power Conversion

System Architecture

PAGE 10

Nuclear Heat

High Pressure Pump

Low Pressure Pump

Preheating Reheating

Separator

Superheating

High Pressure Turbines

3

4

3s

1s

5

5s

6 7

8

9

Mixer

Condenser2

10

11

12

8s

10s

13 14 16 17 18

1 2

290 °C

70 bar

36.51 bar

11 bar 10 bar

2.68 bar

Variable pressure

0.05 bar

15 bar 10 bar 87.5 bar 85 bar

Tertiary

Circuit

Low Pressure

Turbines

Condenser1

15

12.5 bar

Thermal Desalination

Process


Thermodynamic

Modeling Approach

Components are represented using

control volumes to which the principles

of conservation of mass, and energy

(first law of thermodynamics) are

applied.

These principles are typically used to:

Determine the state of the fluid

at the outlet of a component

knowing its state at the inlet.

Calculate the characteristics of

the component, knowing the

state of the fluid at the

boundaries.

PAGE 11

Mass Balance Equation

Energy Balance Equation

Isentropic Efficiencies

(Turbines)

Thermophysical Properties of Fluids and Fluid Mixtures

Mechanical Efficiencies


Simulation Tool

ICV

Provides all the functionalities needed

to simulate Rankine-type power

conversion cycles.

Has a build-in library providing the

properties of steam and water,

including saline-water.

Written in C++:

- Can be used with other languages

such as Python, R.

- Compatible with CEA's SALOME

and URANIE platforms.

PAGE 12


7 MARS 2016 PAGE 13

Component Power (MW)

Steam Generators 2747,99

High Pressure Turbine 1 -150,624

High Pressure Turbine 2 -211,837

Low Pressure Turbine 1 -239,709



Condenser1 (Process) 0

Condenser2 (Tertiary Circuit) -1747,99

Low Pressure Pump 1,69183

High Pressure Pump 15,102

Sum -1,14 10-13

Net Power Output -1000

Power Conversion Efficiency (%) 36,3902

High Pressure Turbine 1; 150,624

High Pressure Turbine 2; 211,837

Low Pressure Turbine 1; 239,709



Point T C P bar X % H kJ.kg-1 E kJ.kg-1.K-1 F kg.s-1

1 290 70 200 2793,98 1048,97 139,405

2 290 70 200 2793,98 1048,97 1385,06

3 245 36,5091 93,2741 2685,23 931,684 245,05

4 245 36,5091 93,2741 2685,23 931,684 1140,01

5 184,07 11 85,9332 2499,41 729,341 1140,01

6 184,07 11 100 2780,67 827,192 979,649

7 275 10 200 2997,9 902,283 979,649

8 145,081 2,685 200 2753,21 633,359 180,999

9 145,081 2,685 200 2753,21 633,359 798,65

10 80 0,474147 93,8269 2500,54 351,599 0

11 80 0,474147 93,8269 2500,54 351,599 798,65

12 32,8755 0,05 86,5162 2234,05 49,7124 798,65

13 32,8755 0,05 0 137,765 -4,22995 979,649

14 32,9654 15 -100 139,492 -2,72166 979,649

15 130,081 12,5 -100 547,394 60,0595 979,649

16 170,264 10 -100 720,471 110,977 1524,47

17 171,56 87,5 -100 730,378 120,02 1524,47

18 230 85 -100 991,385 216,545 1524,47

1s 285,83 70 0 1267,44 336,615 139,405

3s 245 36,5091 0 1061,49 242,266 245,05

5s 184,07 11 0 781,198 131,569 160,363

8s 129,782 2,685 0 545,456 58,7786 180,999

10s 80 0,474147 0 334,949 14,3207 0

If all the steam normally flowing towards Low Pressure Turbine 3 is

redirected to the external process (TSteamEx = 80 C), there will be a

missed electricity production of 213 MWe. The plant would generate

1730 MWth of process heat.


Metrics

W-cost of heat or WCH

Number of MWe of “lost electricity” for

each MWth supplied to the external

process.

Q-cost of heat or QCH

Number of MWth added to core

power, in order to keep the electricity

production capacity at its nominal

value, per MWth supplied to the

external process.

7 MARS 2016 PAGE 14

0

100

200

300

400

500

600

700

30 50 70 90 110 130C

ost of

Pro

cess H

eat

(kW

h.M

Wth

h-1

) Temperature at the Steam Extraction Point (C)

WCH QCH

ECONOMIC COST OF NUCLEAR HEAT

7 MARS 2016

| PAGE 15

CEA |



Levelized costs of electricity

at 5% discount rate

(Germany)

Source: OECD' 2010

Projected Costs of

Generating Electricity

The traditional method for evaluating the cost of process heat consists in multiplying the cost of electricity by the expected

decrease in electricity production.

The thermo-economic method considers the benefits of cogeneration – it allocates CAPEX and OPEX to the two byproducts

–, but also, the constraints introduced by the integrated system – higher expenses, extended construction period, lower

availability, etc. –.

Fuel represents just a

fraction of the cost of

nuclear electricity


SPP DPP

Reference core thermal power (MW th) 2748 3086 (+12,3%)

Reference electric power generation capacity (MWe) 1000 1000

Reference process heat generation capacity (MW th at 80 C) - 1000

Specific construction cost ($ per installed kWe (electric power)) 4101,51 4175,451 (+1,8%)

Specific fuel cost ($ per produced MWeh (electric power)) 9,33 10,478 (+12,31%)

Specific O&M cost ($ per produced MWeh (electric power)) 14,74 15,647 (+6,15%)

Specific decommissioning cost ($ per installed kWe (electric power)) 820,30 835,090 (+1,8%)

Length of the construction period (years) 7 7

Economic lifetime of the plant (years) 60 60

Average availability of the plant (%) 85 84 (-1 point)

Length of the decommissioning period (years) 5 5

Discount rate (%) 5 5

Minimal annual cash in required to have a positive NPV (million $) 433,378 450,979 (+17,601)

Cost of electricity (10-2 $ per kWeh) 5,816 -

Cost of heat (10-2 $ per kWthh at 80 C) - 0,308

Cost of heat (DPP) to cost of electricity (SPP) 5,30%

PWR + MED PWR

Electricity and heat costs

↗ Construction and decommissioning costs

↗ O&M and fuel cost

Discounted cash flow

analysis

↗ Core power

Annual electricity production volume

Annual heat production volume

PAGE 17


0%

2%

4%

6%

8%

10%

12%

30 50 70 90 110 130

Cost of H

eat to

Cost of E

lectr

icity (

%)

Temperature at the Steam Extraction Point (C)

500 750 1000 1250 1500

0%

2%

4%

6%

8%

10%

12%

30 50 70 90 110 130

Cost of H

eat to

Cost of E

lectr

icity (

%)


81% 82% 83% 84% 85%

Size effect ►

◄ Effect of the availability of the

dual-purpose plant

The ratio – cost of heat to cost of

electricity –, calculated based on the

thermo-economic model, is referred

to as the E-cost of heat (ECH).

ECH is subject to the size effect. It

is also sensitive to availability of the

cogeneration plant.


7 MARS 2016 PAGE 19

0

0,2

0,4

0,6

0,8

1

1,2

1,4

30 50 70 90 110 130

Cost

of H

eat (c

$.k

Wth

h-1

)


The thermo-economic approach –

which takes into account

cogeneration's benefits and

constraints – leads to lower cost for

process heat, compared to the

traditional approach, based on the

concept of missed electricity

production.

▲

Thermo-economic

approach

Approach based on

the concept of

missed electricity

production

▼

Impact on the energy

effectiveness of

MED vs. SWRO

MED VS. SWRO

7 MARS 2016

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CEA |


0

2

4

6

8

10

12

14

45 50 55 60 65 70 75

Spec

ific

Po

wer

Co

nsu

mp

tio

n (

kWeh

.m-3

)

Top Brine Temperature (C)

min mid max 1 2 3 4

0

2

4

6

8

10

12

14

45 50 55 60 65 70 75

Spec

ific

Po

wer

Co

nsu

mp

tio

n (

kWh

e.m

-3)

Top Brine Temperature (C)

MED VS. SWRO

Specific power

consumption SWRO

Specific power

consumption MED

Comparable equivalent electric power

consumptions between MED and SWRO

SWRO more energy-efficient

Top brine temperature (C) 75

Temperature at the final condenser

(C)

33

Average temperature drop between

stages (C)

1,85

Number of stages (-) 22

GOR to number of stages 0,85

GOR (-) 18,7*

Pinch point temperature difference,

first effect (C)

5

Steam supply temperature (C) 80

MED specific heat consumption

(kWhth.m-3)

34,285

MED equivalent electric power

consumption (kWe.m-3) – Basis: 1

kWe.m-3

2,97



kWe.m-3

3,97



kWe.m-3

4,97



kWe.m-3

5,97

MED Plant Characteristics

Approach based on the concept

of missed electricity production

▼

Thermo-economic

approach

▼

CONCLUDING REMARKS

7 MARS 2016

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CEA |


CONCLUDING REMARKS

7 MARS 2016 PAGE 23

Summary

This study attempted to evaluate the energetic and economic cost of nuclear heat

based on simplified models.

The power conversion system model provided a basis for assessing:

The W-cost of heat (WCH): number of kWe of missed electricity production per MWth of

process power

The Q-cost of heat (QCH): number of kWth of additional core power, required to keep a

constant level of electricity production, per MWth.

The economic model helped evaluate the E-cost of heat (ECH), defined as the ratio

– cost of heat to cost of electricity –, taking into account cogeneration's benefits.

To identify the most appropriate reactor-process combination, case-specific

evaluations must be performed. CEA in-house tools can support these studies.

THANK YOU FOR YOUR ATTENTION

7 MARS 2016

| PAGE 24

CEA |


7 MARS 2016

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CEA |

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