Nuclear Power Plant Engineering__buet

Power Plan t Engineeri ng Nucl ear Power Acknowledgement: Engr. M. Ali Zulquarnain Director, ROMU, AERE, BAEC

MA Islam, Dept of MECHE, BUET

Wh y Nu clear En erg y? At the present consumption level, known reserves for coal, oil and gas correspond to a duration of the order of 230, 45 and 65 years.

?

Which Primary Energy Source ?

MA Islam, MED, BUET

Wh y Nuclea r En ergy?. .. Only two natural resources have the capability to support long term energetic survival of mankind:

• Nuclear • Solar MA Islam, MED, BUET

and

Nuclea r F uel: Ver y hig h H ea t Value Sl. No.

Fuel

Heat Value (MJ*/kg)

1.

Firewood

16

2.

Brown coal

9

3.

Black coal (low quality)

13 - 20

4.

Black coal

24 - 30

5.

Natural Gas

39

6.

Crude Oil

45 - 46

7.

Uranium** - in light water reactor

500,000

*MJ = Mega Joules, ** Natural U MA Islam, MED, BUET

No G HGs a nd s ma ll a mo unt of wastes Waste Produced: Fuel Consumption:

Coal plant

About 3 million tonnes of coal per year

NPP*

About 27 tonnes of UO2 per year

Each 1000 MWe *NPP: Nuclear Power Plant MA Islam, MED, BUET

7 million tonnes of gaseous & 300,000 tonnes of solid wastes per year 0.7 tonne of high level radioactive waste per year

Compa rati ve carbo n emi ssi on Source

Kilograms of carbon per MW-h produced

Nuclear fission

4

Geothermal

79

Gas

430

Oil

828

Coal

955 Coal-fired power station, Bombay

Source: British Royal Academy of Engineering (2006) MA Islam, MED, BUET

Ea sy transpor ta tion of f uel 1000 MW Coal Fired Plant

1000 MW NPP*

≈ 2 tons )

*NPP: Nuclear Power Plant MA Islam, MED, BUET

………………………. ………………………. ……………………….

30 trainloads of coal per months (260,000 tons)

Co mparative ele ct ric it y pro duct ion co st s per MW- h ( UK da ta ): Source

Cost £/MW-h

Nuclear fission

23

Gas

22

Coal

25−32

On-shore wind On-shore wind with back-up Off-shore wind Off-shore wind with back-up Source: British Royal Academy of Engineering (2006)

MA Islam, MED, BUET

30 54 55 72

Co mpara tive ele ct rici ty pro duct ion co st s per M W- h ( US data ): Source Nuclear fission

Cost $/MW-h 17.2

Coal

22.1

Gas

75.1

Oil

80.9

Source: Nuclear Energy Institute (2006)

MA Islam, MED, BUET

Is Nu cl ear Ener gy Saf e?

• Maturity of technology: Nuclear power reactors have attained maturity over 50 years of operation.

MA Islam, MED, BUET

Is Nuclea r En erg y Safe?. ..

• Multiple barriers: Multiple barriers like (1) fuel matrix, (2) fuel cladding, (3) reactor pressure vessel as well as primary piping and (4) containment building are used to prevent any release of radioactivity into the atmosphere. The containment building contains any accidental release of radioactivity from the reactor primary cooling system. MA Islam, MED, BUET

Mu lti ple b ar riers

Length: about 7m No. of assemblies: 190 (for a 1000MW reactor)

PWR Fuel A ss embly MA Islam, MED, BUET

Multiple barriers…

PROTECTION AGAINST EXTERNAL HAZARDS

MA Islam, MED, BUET

Is Nuclea r En erg y Safe?. ..

• Two major accidents: Only two major nuclear accidents occurred so far, namely the Three Mile Island (TMI) accident and in 1979 and the Chernobyl accident is 1986.

MA Islam, MED, BUET

TMI acci den t TMI Unit-2

TMI Unit-2 Reactor: Power: 900 MWe Type: PWR (Pressurized Water Reactor) Date of accident: 28 March, 1979 Loss of life/over exposure to radiation:

TMI: Three Mile Island MA Islam, MED, BUET

None

Note: TMI Unit-1 is a 800 MWe PWR commissioned in 1974 The reactor is still operating with very good records.

Ch er nobyl acci den t Chernobyl Unit-4 Reactor: Power: 1000 MWe Type: RBMK (Graphite moderated BWR) Date of accident: 26 April, 1986 Loss of life: 56 (as of today) Cases of cancer: 4000 Evacuation & resettlement: 300,000 Note: The accident produced contamination level, which was 400 times of that produced by the Hiroshima bomb. MA Islam, MED, BUET

TM I & C her nobyl ac ci den ts Both of the accidents occurred mainly because the operators had disabled the safety systems of the reactors.

MA Islam, MED, BUET

Coal m ine acc id en t

Death of more than 25,000 people in 5 years!!

Source: http://www.china.org.cn/english/China/239291.htm MA Islam, MED, BUET

Is Nuclea r En erg y Safe?. ..

• Subsequent improvements: Lessons learned from these two major accidents and other minor ones helped to improve both design and operational procedures of nuclear reactors.

MA Islam, MED, BUET

Is Nuclea r En erg y Safe?. ..

• Safety features: Present day nuclear reactors incorporate unique, reliable, tested and fail-safe safety features to minimize nuclear accidents.

• Reduced accident rate: As a result, no nuclear accident involving any significant release of radioactivity to the atmosphere took place since Chernobyl accident in 1986.

MA Islam, MED, BUET

Is Nuclea r En erg y Safe?. ..

• WANO: The World Association of Nuclear Operators (WANO) ensures adherence to high level of safety by setting international benchmarks.

• Nuclear wastes: All high level radioactive wastes are being stored safely. Many proposals for their safe management and disposal are now under active consideration.

MA Islam, MED, BUET

Is Nuclea r En erg y Safe?. .. “Today, the waste disposal issue is not a technical problem but one of public and political acceptance.” ---- IAEA Bulletin, Volume 47/2, March 2006

MA Islam, MED, BUET

Is Nuclea r En erg y Safe?. ..

• 439 nuclear reactors are operating in 31 countries.

• Worldwide 12 countries are constructing 32 new nuclear power units.

• Eighteen of the reactors under

construction are of the Pressurized Water Reactor (PWR) type.

MA Islam, MED, BUET

Is Nuclea r En erg y Safe?. ..

• Nine countries are panning to

construct 31 more nuclear power units.

• Fifteen countries are considering

whether to construct 73 more nuclear power units.

MA Islam, MED, BUET

Nuclear vs. fossil power plant Nuclear power Fossil-fired plant with pressurized power plantwater reactor

•Fossil and nuclear power plants differ in the way generating the heat for„Nuclear steam turbines reactors are the most complicated way of boiling water” (Einstein) MA Islam, MED, BUET

Nu cl ear React ors

What is a Nuclear Reactor?

MA Islam, MED, BUET

Nu cl ear React ors… Answer: Nuclear Reactor is a system / device where a nuclear reaction takes place. MA Islam, MED, BUET

Nu cl ear React ors… Examples of Nuclear Reactors: ITER (1) Fusion Reactor

(2) Fission Reactor (3) Accelerator Driven System (ADS) OR Spallation Reactor

MA Islam, MED, BUET

PWR

Nu cl ear React ors… (1)

Fusion Reactors:

1. The Sun & the Stars Fusion Reactors)

MA Islam, MED, BUET

(Natural

100 billion X 100 billion

Nu cl ear React ors… (1) Fusion Reactors…: 2. ITER (International Thermonuclear Experimental Reactor)

• Construction started in France in 2006. • Cost is approximately €10 billion ($12.1 billion). • The program is anticipated to last for 30 years: 10 years for construction, and 20 years of operation. • First plasma operation is expected in 2016. MA Islam, MED, BUET

Nu cl ear React ors… (1) Fusion Reactors…: 2. ITER (International Thermonuclear Experimental Reactor)…

ITER is designed to produce approximately 500 MW of fusion power that can sustain for about 500 seconds. MA Islam, MED, BUET

Nucl ear Fissi on… Generation-1 Neutron

MA Islam, MED, BUET

Generation-2 Neutron

MA Islam, MED, BUET

Nucl ear Rea ctors… (2) Fission Reactors: 1 235 236* 98 136 n ( slow ) + U  → U  → Zr + Te + 2n + Energy 0 92 92 40 52

Gen-2

Gen-3

E = mc

2

Energy / fission: 200 MeV (≈ 1 MWD / g) No. of neutrons / fission: 2.43 MA Islam, MED, BUET

(200 Mev)

U238

U235 Natural abundance U-isotopes: (c)

U-238 : 99.3%

(d)

U-235 : 0.7%

Nucl ear r ea ctor oper ation princ iple ...

MA Islam, MED, BUET

Nucl ear r ea ctor oper ation princ iple ... Ho w a F issi on React or Wo rks? •

A Super Critical Assembly (SCA) of fissile material (U-235, U-233 & Pu-239) is made Sub-critical by inserting neutron absorber materials (Cd, C, B, etc.) in it.

•

The neutron absorber materials are known as the Control Rods. The SCA along with the Control Rods is known as the Reactor Core.

MA Islam, MED, BUET

Nucl ear r ea ctor oper ation princ iple ... Ho w a F issi on React or Wo rks?... •

When the Control Rods (CRs) are gradually withdrawn from the reactor core in presence of a neutron source, Criticality is achieved.

•

Further withdrawal of the CRs makes the core super critical and help increase the power level of the reactor.

MA Islam, MED, BUET

Nucl ear r ea ctor oper ation princ iple ...

Ho w a F issi on React or Wo rks?... •

Reactor power level decreases when the Control Rods (CRs) are gradually inserted into the core.

•

Total insertion of the CRs makes the reactor sub-critical. And we call that the reactor is in shutdown condition.

MA Islam, MED, BUET

Typ es o f R eac tor Purpose: 2. Power Reactors 3. Research Reactors

Coolant / Moderator:

2. 3. 4.

Light Water Reactors Heavy Water Reactors Gas Cooled Reactor

Energy of ‘n’ causing fission:

• Thermal Reactor (E ≈ 0.025 eV) • Fast Reactors (E ≥ 1.0 MeV) MA Islam, MED, BUET

Typ es of React or… Power Reactors: • LWRs (Light Water Reactors)

– PWR (Pressurised Water Reactor)

– BWR (Boiling Water Reactor) -- Russian RMBK Reactor MA Islam, MED, BUET

Typ es of React or… Power Reactors…:

• PHWR (Pressurised Heavy Water Reactor) OR CANDU (Canadian Deuterium Uranium)

• HTGR (High Temperature Gas Cooled Reactor)

• LMFBR (Liquid Metal Cooled Fast Breeder Reactor)

MA Islam, MED, BUET

Typ es of React or… PWR :

MA Islam, MED, BUET

PWR: Pressurized Water Reactor

Types of Reactor… Sectio nal View o f a PWR

MA Islam, MED, BUET

PWR: Pressurized Water Reactor

Typ es of React or… PWR …: Dimensions of a typical PWR reactor pressure vessel: Height

: 15 m (49 ft)

Diameter

: 5 m (16 ft)

Wall

: 25 cm (10 in) thick steel

Containment : 1 m thick concrete (steel lined) Core loading : 82 tons of UO2 Pressure (Pri.) : 2250 psig (158 Atmos ) MA Islam, MED, BUET

PWR: Pressurized Water Reactor

Typ es of React or… PWR …:

Arrangements of RPV, Steam Generators, Primary pumps, Pressurizer, etc. RPV: Reactor Pressure Vessel

MA Islam, MED, BUET

Typ es of React or… BWR :

MA Islam, MED, BUET

BWR: Boiling Water Reactor

Typ es of React or… PH WR / C AN DU: PHWR:

Fuel Bundle

MA Islam, MED, BUET

PHWR: Pressurized Heavy Water Reactor

Typ es of React or… Dis tri but io n of wo rl d’s 439 reactors amo ng t he R eactor Ty pes me ntio ned: Reactor Type PWR

Qty. % of Total : 266 (61%)

BWR PHWR

: 94 : 40

(21%) (09%)

HTGR RBMK

: 23 : 12

(05%) (03%)

LMFBR TOTAL

: 04 : 439

(01%)

MA Islam, MED, BUET

Status of NPPs: World Perspective

MA Islam, MED, BUET

Status of NPPs: World Perspective…

MA Islam, MED, BUET

Co ntri butio n of NP P* to Ele ct ri c Power P roduct ion

% of total production : 16%

16%

MA Islam, MED, BUET

*NPP: Nuclear Power Plant

NP Ps in Operati on

CANDU Reactors at Pickering, Canada

MA Islam, MED, BUET

NP Ps in Oper ati on… Diablo Canyon - CA

PWRs in Diablo Canyon - CA , the USA PWR: Pressurized Water Reactor

MA Islam, MED, BUET

NP Ps in Oper ati on…

CANDU at Qinshan, China

MA Islam, MED, BUET

NP Ps in Oper ati on… A BWR in Japan

MA Islam, MED, BUET

NP Ps in Opera ti on…

MA Islam, MED, BUET

Generations of Nuclear Reactors Generation III+ Generation III Generation I Early Prototypes

- Shippingport - Dresden - Magnox

1950

1960

Gen I

Generation II Advanced LWRs

Generation IV Revolutionary Designs

Evolutionary Designs

Commercial Power

- CANDU 6 - System 80+ - AP600

- PWRs - BWRs - CANDU

1970

1980

Gen II

1990

2000

Gen III

- ABWR - ACR1000 - AP1000 - APWR - EPR - ESBWR 2010 2020

Gen III+

- Safe - Sustainable - Economical - Proliferation

Resistant and Physically Secure

2030

Gen IV

http://www.gen-4.org/Technology/evolution.htm

MA Islam, MED, BUET

Ge nera tion-III + React ors Advan ced Pas sive Rea ctor

MA Islam, MED, BUET

Ge nera tion III+ React ors… Advanced Re actors : AP10 00 Pa ss ive)

(Adv anc ed

Features: – Light water reactor (LWR) – Passive systems (gravity, natural circulation, compressed gas, etc.) ensures safety – 36 month construction period – 60 years design life

MA Islam, MED, BUET

Wast e Man ag em en t

MA Islam, MED, BUET

Waste Management… 146

t

Nuc lear Fuel Cyc le

1000 MW NPP

Yellow Cake

MA Islam, MED, BUET

Nu cle ar Fuel Cyc le UO2

UF6 U3O8

MA Islam, MED, BUET

Conten ts of fresh & spen t fuel s Fresh Fuel

Spent Fuel

Contents

• More than 99% of the radioactivity produced during the fission reaction is retained in the fuel rods. • The balance 1% is within the reactor structure.

Fresh Fuel

Spent Fuel

U-238

967

943.00

U-235

33

8.00

FP

35.00

Pu

8.75

U-236

4.60

TUE

0.65

Total (kg):

1000

1000.00

FP: Fission Products; TUE: Transuranic elements MA Islam, MED, BUET

Wast e M an ag em en t… Contents of Spent Fuel

• 96% U (w/EL at about 0.8%) • 3% Fission Products (FPs) • 1% Pu & Minor Actinides (MA) EL: Enrichment Level

MA Islam, MED, BUET

Wast e M an ag em en t… How much wastes are produced per year from a 1000 MW NPP?

• • •

27t of high level waste; if reprocessed, this gives 3m3 or 8t of wastes to be disposed of. 300t of intermediate level of waste. 450t of low level waste.

Coal fired plant with best available pollution abatement:

• •

6.5Mt of CO2; 20,000t of SO2; 4,000t of NO2 300,000t of ash; 400t of heavy metals including Hg, Cd, Pb, As, and Vd (Vanadium).

MA Islam, MED, BUET

Wast e M an ag em en t… Three general principles employed in the management of radioactive wastes:

• • • MA Islam, MED, BUET

Concentrate-and-contain. Dilute-and-disperse. Delay-and-decay.

Wast e M an ag em en t… Concentrate-and-contain

• This block contains material chemically identical to vitrified highlevel waste from reprocessing of spent nuclear fuel.

• A piece of this size would contain the total high-level waste arising from nuclear electricity generation for one person throughout a normal lifetime. MA Islam, MED, BUET

Wast e M an ag em en t… Concentrate-and-contain…

• High level wastes can be stored in repositories for hundreds of years.

• Egyptian pyramids survived for several thousands years. So, with the modern technology, it is quite possible to build structures that can survive even for longer period of time.

MA Islam, MED, BUET

Wast e M an ag em en t… Delay-and-decay

• After 50 years, the spent fuel removed from a reactor has less than one thousandth of its initial radioactivity.

MA Islam, MED, BUET

Wast e M an ag em en t… Delay-and-decay…

• Even after one year, typical spent fuel generates decay heat at a rate of about 10 kW/t.

• After ten years the decay heat rate decreases to about 1 kW/t. MA Islam, MED, BUET

Wast e M an ag em en t…

Wet Storage Facility for the Spent Fuels MA Islam, MED, BUET

Spent fu el st ora ge… Dry Storage for Spent Fuel at Reactor Site

MA Islam, MED, BUET

Wast e M an ag em en t…

Transportation of Spent Fuel back to the country of origin after 10-30 years of cooling MA Islam, MED, BUET

What is Radiation?  Atoms are the building blocks of all material. If atoms contain excess energy, they are unstable. Materials that are composed of unstable atoms will naturally emit radiation in order to release the excess energy and reach a stable state. The radiation is emitted in waves or particles of energy. Thus radiation can be defined as energy emitted from the nucleus of unstable atoms in the form of particles or waves.  Radiation is not new or limited to nuclear power plants. Each of us is exposed to some radiation every moment of our lives from radioactive materials that exist in nature.

MA Islam, MED, BUET

Natural Radiation  Natural radiation is a by-product of processes and materials created when the earth was formed. The sun on which we all depend for heat and light produces very highly charged particles called cosmic rays. We are exposed continuously to this radiation every day.  Not many people realize that we all have radiation sources within our bodies, usually in the form of potassium. Radioactive potassium occurs naturally in the earth and is therefore present in trace amounts in the food we eat and the water we drink.

MA Islam, MED, BUET

Natural Radiation….  Additionally, radioactivity from uranium and thorium is found in rocks and soil. For example, radon gas is a source of radiation that results from the decay of uranium found in the earth. Radon gas has recently been identified as a concern because it can penetrate through the foundation of homes. Recent studies show that radon gas contributes more than half of our radiation exposure each year.

MA Islam, MED, BUET

Man-Made Radiation  X-ray machines are used for dental and medical purposes, television sets are used for entertainment and microwave ovens are used to cook foods.  Nuclear power plants use the energy of radiation to convert water to steam, which is then used to generate electricity.

MA Islam, MED, BUET

Measuring Radiation  Each type of radiation has somewhat different characteristics. It is possible to measure the biological effects of the different types of radiation in terms of a unit of exposure called a "rem". This is a relatively large unit, so the biological effects of radiation are described in millirem, which are a thousand times smaller than a rem.  Radiation measurement techniques are highly advanced and can detect small changes in the environmental radiation level. Results of extensive environmental radiation monitoring confirm that routine plant operation does not contribute a significant amount of radiation exposure.

MA Islam, MED, BUET

Measuring Radiation….  People living near a NPP receive less than one millirem a year due to the plant's operation. This compares to the 360 millirem of exposure received annually from natural background radiation and other man-made sources.  Since every living thing on earth has been continuously exposed to radiation, such exposure is normal. The level of exposure from natural radiation and man-made sources is considered very low-level exposure.  Scientists continue to study the risks associated with low-level radiation exposure to determine its effects on humans. The studies show that negative health effects caused by low-level exposures cannot be distinguished from those caused by other environmental hazards. After more than 80 years of study, radiation is readily detected, understood and strictly regulated. MA Islam, MED, BUET