Mengenal Reaktor NuklirDr. Eng. Pribadi Mumpuni Adhi

Politeknik Negeri Jakarta2018 1

Perbedaan Thermal PP dan NPP

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History of nuclear power

1938– Scientists study Uranium nucleus

1941 – Manhattan Project begins

1942 – Controlled nuclear chain reaction

1945 – U.S. uses two atomic bombs on Japan

1949 – Soviets develop atomic bomb

1952 – U.S. tests hydrogen bomb

1955 – First U.S. nuclear submarine

Reaksi Fisi Berantai

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Contoh reaksi fisi

Neutron induced fission

Inti berat dapat pecah jika ditumbuk • Tumbukan menyebabkan nucleon

kehilangan keadaan setimbangannya• Tumbukan yang keras merupakan

kondisi terbaik untuk menginduksi fisi• Neutrons merupakan proyektil ideal

untuk menginduksi fisi

Perbandingan Energi Nuklir dengan Energi Kimia

• C + O2 ➔ CO2 + 4 ev

• U-235 + n ➔ FP1 + FP2 + (2 atau 3) n + 200 Mev

• 1 eV = 1,6 x 10-19J

• 1 gram U-235 = 1/235x6,02x1023x200Mev

= 8,197x1010 Joule

= 8,197x1010/24/3600=0,949x106 watt day

~ 1 MWday

Note : Untuk 100% U-2357

Mini Quiz (1)

Jika diasumsikan energi yang dihasilkan oleh batu baraberasal dari pembakaran karbon. Maka untukmenghasilkan energi sebesar 1 MWd dibutuhkanberapa ton batu bara?

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Answer

C + O2 ➔ CO2 + 4 ev

1 gram C = 1/12 x 6,02x1023 x 4ev = 3.81 x 104J

1 MWd = 1 x 106 x (24x3600) = 8.64 x 1010 J

Sehingga untuk menghasilkan energi setara 1g U-235 dibutuhkan batu bara sebanyak 2,27 x 106 g atau 2,27 ton

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Evolusi Reaktor Daya

http://www.whitehouse.gov/ 10

Evolusi Reaktor Daya (Generasi Reaktor)

• Gen I• Prototypes in 50’s & 60’s

• Gen II• 70’s & 80’s• Today’s Operational Reactors• BWR, PWR, CANDU, …

• Gen III• ABWR, APWR• Approved 90’s• Some Built around the World

• Gen III+• Current Advanced Designs in

the Approval Process• Pebble Bed Reactor

• Gen IV• Deploy in 2030• Economical• Safe• Minimize Waste• Reduce Proliferation

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Klasifikasi Reaktor Nuklir Fisi

• Berdasarkan perbedaan spektrum energi neutron

• Fast reactor

• Thermal reactor

• Berdasarkan jenis material yang digunakan sebagai moderator dan pendingin

• Gas (Magnox, AGR, HTGR)

• Air (LWR → BWR dan PWR, SCWR)

• Air berat (CANDU)

• Logam cair (SFR, LFR)

• Garam cair (MSR)

• Bardasarkan fungsi

• Reaktor riset (di BATAN)

• Transmutasi (ADS),

• Reaktor daya (LWR dll)12

Klasifikasi Reaktor Daya

Reactor types Reactor names Moderator Coolant

Thermal

reactors

Magnox GCR Graphite CO2

AGR Graphite CO2

PWR H2O H2O

BWR H2O H2O

BLWR(FUGEN) D2O H2O

PHWR(CANDU) D2O D2O

HTR Graphite He

THTR Graphite He

RBMK Graphite H2O

Fast reactor LMFBRs None Na or

Pb/Pb-Bi 13

Komponen Utama Reaktor Nuklir

1. Fuel (Bahan Bakar)

2. Moderator

3. Control Rods (Batang kendali)

4. Coolant (Pendingin)

5. Steam Generator

6. Turbine/Generator

7. Pumps

8. Heat Exchanger

9. CondenserReactor cooling tower

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Bahan Bakar

Enriched Fuel pellet

Properties of Uranium Oxide (UO2)

Melting point 2865 0C (5189 0F)

Density (x-ray measur.) 10.97 g/cc

Thermal conductivity 4.777 x 10-3 W/m.K at 20 0C

1.91 x 10-3 W/m.K at 1000 0C

Thermal expansion coef. (per 0C)

~1x10-5/ 0C (0 – 1000 0C)

Tensile strength 6.9 x 107 Pa (10,000 psi)

Modulus elasticity 1.72 x 1011 Pa (25x106 psi)

Cell type Face-centered cubic

Uranium-235 enrichment: 3 – 5%Max enrichment (allowed): 20%

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Bahan Bakar

Radial fuel element geometry

Zircaloy

UO2

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Mini Quiz (2)

Mengapa ada gap antara clad material dan fuelmaterial?

1. Agar mudah dalam proses fabrikasi(memasukan fuel pellet ke cladding)

2. Untuk mencegah cladding rusakapabila terjadi fuel swelling

Answer

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Pressurized Water Reactor (PWR)

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Schematic Diagram PLTN1. PWR

http://www.nrc.gov/Water supply pump

Circulation pump

To sea

Sea water

Steam

Water

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Mini Quiz (3)

1. Apa yang dimaksud dengan saturation temperature(temperature jenuh) air dan berapa Tsat air padatekanan 0.1 Mpa?

2. Mengapa tidak terjadi aliran dua fasa (two phaseflow) pada primary loop PWR sedangkan padasecondary loop terjadi?

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PWR Coolant Circuits

• Siklus tidak langsung : Primer dan Sekunder coolant loop

• Aliran fluida satu fasa pada reactor coolantTin = 287,7oC; Tout = 324oC; P=15.2 Mpa; Tsat = 343.2oC

• Aliran fluida dua fasa pada power conversion cycle loopTS,G = 227oC; TSG,out = 285oC; P=6.9 Mpa,Tsat=285oCTcondenser=37,8oC; 6,6kPa

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Diagram Fasa Air

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Aliran pada reactor vessel

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PWR

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Structure Fuel Assembly PWR

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Typical 4-Loop Core

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Control rod pada PWR

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Control rod pada PWR (Westinghouse)

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Susunan Primer 4-Loop pada PWR Westinghouse

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PWR PressurizerPressurizer (Saturated Liquid-Steam system: P=15,5 MPa; T=344,7oC)Control pressure in the primary system

- Pressure can be raised by heating water (electrically)

- Pressure can be lowered by condensing steam (on sprayed droplets)

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Steam Generator (Westinghouse)

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Steam Generator

Primary side,, Hot (Tin = 324˚C,, Tout = 288˚C)): High Pressure Liquid

Secondary side, Cold (Tsat = 285˚C): Lower Pressure Steam and Liquid

• Water boils on Shell Side of Heat Exchanger

• Steam Passes through Liquid Separators, Steam

Dryers

• Liquid Water Naturally Recirculates via Downcomer

• Level controlled via steam and feedwater flowrates

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Reactor Coolant Pump

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to provide forced primary coolant flow to remove the amount of heat being generated by the fission process

Summary PWR

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https://www.youtube.com/watch?v=_UwexvaCMWA

Boiling Water Reactor (BWR)

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http://www.nrc.gov/

Schematic Diagram PLTN2. BWR

Water supply pump

Circulation pump

To sea

Sea water

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BWR Coolant Circuit

• Siklus langsung

• Aliran Fluida dua fasa

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BWR Vessel

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Structure Fuel Assembly BWR

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Reactor Core (Teras Reaktor) BWR

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BWR Control Rod

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Mini Quiz (5)

Mengapa control rod pada BWR dimasukkan daribawah bukan dari atas?

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Steam Separator

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Steam Dryer

References

• Abdul Waris, Kuliah Topik Khusus Fisika Reaktor, ITB

• Jacopo Buongiorno, MIT OCW

• J.J. Duderstadt, 1976, Nuclear Reactor Analysis, John Wiley and Son

• Minoru Takahashi, Nuclear Energy System Course, Tokyo Tech

• USNRC Technical Training Center, Pressurized Water Reactor (PWR)

• USNRC Technical Training Center, Boiling Water Reactor (PWR)

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