Prof. Dr. Haluk UTKU Institute of Nuclear Sciences Hacettepe University Ankara, Turkey PRESSURIZED WATER REACTORS.

Prof. Dr. Haluk UTKUInstitute of Nuclear Sciences

Hacettepe UniversityAnkara, Turkey

PRESSURIZED WATER REACTORS

GENERAL SYSTEM

March 27-28th, 2008, WORLD CONJUNCTURE IN NUCLEAR TECHNOLOGY: Generation III and III+ Nuclear Power Plants, Istanbul

Picture: Mıtsubishi Heavy Industries

REACTOR VESSEL

27-28 Mart 2008, NÜKLEER TEKNOLOJİDE DÜNYA KONJONKTÜRÜ: III. Ve III+ Nesil Nükleer Reaktörler Kongresi, İstanbul

REACTOR VESSEL

Height (m) 11.5-13.5

Thickness (mm) 180-255

Internal Diameter (m) 3.4-5.2

Weight (ton) 240-590

Max. Pressure (Atm.) 170

Max. Temperature (oC) 343

Material Manganese Molibdenium Steel (Linen: Stainless Steel, 3.2 mm)

Core Barrel

Vessel Head

Control RodThimble Guide

Coolant Inlet Nozzle

Coolant Outlet

Vessel

Control RodDrive Mechanism

Rod ClusterControl Mechanism

FuelNeutron Reflector


REACTOR CORE DIMENSIONS

MWe 600 900 1200 1500

Power (MWth) 1650 2652 3411 4451

Core Equivalent

Diameter (m)2.5 3.0 3.4 3.9

Core Active

Height (m)3.7 3.7 3.7 3.7

Total Fuel Assembly 121 157 193 257


FUEL

Pictures: GE, Mitsubishi Heavy Ind., Westinghouse

Top CoolantFlow Nozzle

BottomFlow Nozzle

Filter

InstrumentationGuide at the Center

Grid

Control RodGuides

Fuel Rods


FUEL

Total Fuel Assembly* 121 - 257

Assembly Lattice 14x14 – 17x17

Distance Between Fuel Rods

in an Assembly(cm)

0.31 cm

Fuel Rod Diameter (cm) 0.94

U-235 enrichment (%) 1.9 – 4.95

Core Total Fuel Weight (ton) 89 - 121

Burnup (MWd/MTU) 33000 - 60000

* For a reactor with 193 fuel assambly there are 51000 fuel rods and approximately 18 million fuel pelets.


FUEL FAILURE RATES IN US PLANTS

CONTRIBUTION OF FUEL CYCLE TO POWER GENERATION COST

Maintenance-Operation+Investment Fuel Cycle

Natural Uranium and Processing (%2.6)

Enrichment (%3.6)

Production of Fuel Assembly (%2.6)

Disposal (%11.2)

%20%80


Ractor Vessel

PressurizerSteamGenerator

CoolantPump

Reactor Coolant Pressure (Atm.)

Secondary System Presssure (Atm.)

~153

~ 60

Coolant Flow Rate (m3/h/loop) 2.01x104 for 3420 MWth

2.58x104 for 4450 MWth

Pump Shaft Power (kW)

ΔP (Atm.)

4470 – 7460

6

Coolant Inlet Temperature (oC)

Coolant Outlet Temperature (oC)

~ 288

~ 328

REACTOR CORE COOLANT SYSTEM


Coolant Pump

Coolant Pump - Pressurizer

Pressurizer


•Recirculating Steam Generators:Westinghouse-USA; Mitsubishi Heavy Industries-Japan; Siemens-Kraftwerke-Germany; Babcock & Wilcox-Canada

•Once-Through Steam Generator:Babcock & Wilcox, USA

•Horizontally Placed Steam Generators:Zio, Atommash-Russian; Vitkovice-Check

STEAM GENERATORS


Primary Inlet Primary Outlet

Steam Outlet

Steam Separators

Feedwater Inlet

Downcomer Annulus

Tube Sheet

Tube Supports

Tube Bundle

RECIRCULATING STEAM GENERATORS

References:www.kntc.re.kr


ONCE-THROUGH AND HORIZONTAL STEAM GENERATORS

Reactor coolant flow tubesı

From Reactor

To Reactor

Perforated plates

To Turbine

Steam Generator

Pressure 63 Atm.Feedwater Temp. 220-225 oCMoisture at the outlet 0.2%

CONTAINMENT BUILDING

Containment Design relies on calculating the peak containment pressure during potential accidents. The containment must withstand the pressure and temperature of Design Basis Accident without exceeding the design leakage rate of 0.2% volume/day for the 24 hours and 1% volume/day thereafter. Steel linen is used inside to protect from any gas diffusion.

Applied Regulations:10 CFR 50, Appendix A, General Design Criteria 52, 53 and 54 10 CFR 50, Appendix J


CONTAINMENT BUILDING

Sandia National Laboratories, USA conducted a test of slamming a jet fighter into a large concrete block at 775 km/h airplane left a 6.4 cm deep gouge in the concrete. Although the block was not constructed like a containment building missle shield, the results were considered indicative.In another work EPRI, Electric Power Research Institute, conducted a aircraft crash impact analysis. Analysis showed that no parts of the aircraft entered the containment buildings. The robust containment structure was not breached (Boeing 767-400, weights 203 tons with full fuel, the wing span is 51.5 m.)


• Decay heat removal system after shutdown• Residual heat removal system• Emergency core cooling cystem• Containment spray system• Radiation control systems• Systems to filter accumulated gas in the

containment

ENGINNERING SAFETY FEATURES


Relative deviation from the criticalitiy is called reactivity.

1. Shutdown Rods2. Gray Rods3. Dark Rods4. Xenon5. Fuel Temperature reactivity feedback6. Moderator (Coolant) Temperature & boron reactivity feedback

Note that reactivity is a computed parameter, and not a measured parameter. It is not directly available at an actual plant.

THE REACTIVITY CONTRIBUTIONS OF DEVICES AND PHYSICAL PHENOMENON


Prof. Dr. Haluk UTKU Institute of Nuclear Sciences Hacettepe University Ankara, Turkey PRESSURIZED WATER REACTORS.

Documents

nuclear technology

nuclear power plants

world conjuncture

fuel rods

fuel pelets

mwthpump shaft power

peak containment pressure

design leakage rate