W’s AP600 &AP1000

by T. G. Theofanous

In-Vessel Retention

• Loviisa VVER-440 first (1979)

• Westinghouse's AP-600 (1987) FRR’ 17

• Korean KNGR and AP1400 (1994)

• Westinghouse’s AP-1000 (2004)

• NUPEC’s BWR’s (2000)

The AP-600 work took three years it involved ~10 FTE’s and was finalized with 17 experts

AP-600 The final bounding state

Phenomena of In-Vessel Melt Retention

Framework for Addressing IVR

Thermal Regime

Framework for Addressing IVR

FCI Regime

Research to Support Assessment of

IVR Thermal Loads

The Basic Geometry and Nomenclature of In-vessel Retention in the Long-term, Natural Convection-Dominated, Thermal Regime

Schematic of the Physical Model

Used to Quantify Emergency Energy Partition, and Thermal Loads in the Long-term, Natural Convection Thermal Regime. Also Shown is the Nomenclature used in the Formulation of the Mathematical Model.

Schematic of the ACOPO facility

Internal temperature

sensors

temperature difference

Data Acquisition & Control System

Pump Rack

Venturi RackTest Vessel

Heat Sink

flow ratescontrol to 15 pumps

Expansion Tank

Windows

The ACOPO facility

33.4”30.5”28.5”24”21.517”13.5”10.5”7”3.5”0.75”

72”

12

34

5

6

7

8

9

10

1112131415

expansion volume

Cooling Unit #7

thermocouple position

silicone insulation

1/4 inch square copper

tubing

inlet

outlet

thermistors

venturi

33.75”

The heat flux distribution on the lower boundary of a naturally convecting hemispherical pool

ACOPO

Nusselt number dependence on external Rayleigh number

Heat Flux at the Pool Upper Corner

(Churchill-Chu, 1975)

ACOPO (1998)

The oxides pool Nusselt number, as a function of theRayleigh number and the “fill” fraction, H0=R

Nup;up/Nup as function of Ra0 and H0=R

Num/Nuup as function of Raq, Hm/R, and G

G is a new dimensionless group reflecting materials properties.

Hm/R = 0.1

Hm/R = 0.2

Hm/R = 0.3

Hm/R = 0.4

Lines within each Hm/R group correspond to emissivity (bottom to top) 0.45; 0.55; 0.65; 0.75

Research to Support Assessment of

IVR Heat Removal Capability

Schematic of the ULPU facility: Configuration III

The ULPU facility

A temperature transient (local microthermocouple response) associated with boiling crisis

150

160

170

180

190

200

210

0 5 10 15 20 25 30 35

Tem

pe

ratu

re [o C

]

Time [s]

Critical heat flux as a function of angular position on a large scale hemispherical surface

ULPU-2000

Schematic of the ULPU facility: Configuration IV

New Configuration IV CHF results (data points), relative to curren (AP600) technology

ULPU-2000

Schematic of the mini-ULPU facility

5. 0 cm

Microthermocouples (5)

Heaters (4)

Bottom View of Heater (10 cm long)

4. 0 cm

Motor Frequency Controler

Data Acquisition

Power Controler

Water Tank

Water Heaters

Water InWater Out

Insulation

Steel or Copper

Heaters

Cam

The mini-ULPU Experiment

The mini-ULPU Experiment

The Critical Heat Flux Data Obtained in mini-ULPU

Contact Frequency, Hz

----□---- Copper

-------- Steel

Both Surfaces are Well-Wetted

Crit

ical

Hea

t F

lux,

kW

/m2

200m

100m

130m Glass

• Heater 20x40 mm• Constant Flux, Verified Infinite Flat Plate Behavior

100 nm Ti

Flash X-Ray (5 ns)

Film

High-speed IR 2kHz (5kHz)

High-speed video

100m

Seeing is believing

The BETA Experiment

The Critical Heat Flux Data Obtained in BETA

CHFK-Z = 1.2 MW/m2

Generalization

In-Vessel Retention for Larger Power Reactors

The Coolability Region of an AP600 reactor for different cooling options and metal layer emissivity

Lines in each group correspond to fraction of Zr taken to be oxidized (0.2; 0.4; 0.6; 0.8)

Pool Boiling = 0.45

N/C Boiling = 0.45

N/C Boiling = 0.8

The Coolability Region of an GE-BWR reactor for different cooling options and metal layer emissivity

Lines in each group correspond to fraction of Zr taken to be oxidized (0.2; 0.4; 0.6; 0.8)

Pool Boiling = 0.45

N/C Boiling = 0.45

N/C Boiling = 0.8

GE-BWR

The Coolability Region of an W-PWR reactor for different cooling options and metal layer emissivity

Lines in each group correspond to fraction of Zr taken to be oxidized (0.2; 0.4; 0.6; 0.8)

Pool Boiling = 0.45

N/C Boiling = 0.45N/C Boiling

= 0.8

W-PWR

The Coolability Region of an Evolutionary PWR reactor for different cooling options and metal layer emissivity

Lines in each group correspond to fraction of Zr taken to be oxidized (0.2; 0.4; 0.6; 0.8)

Pool Boiling = 0.45

N/C Boiling = 0.45

N/C Boiling = 0.8

E-PWR

Making the case for AP1000

AP1000 IVR Thermal Margin

Estimates based on AP600 Technology

Thermal Load

AP600

AP1000

Coolability Limit (CHF)

ULPU-V as Simulation Tool of AP1000

• Full Length;

with Heat Flux Shaping we have Full Scale Simulation

• Complete Natural Circulation Path of AP1000 Represented as 1/84-Slice and Matched Resistance (Flow Areas and Geometry) as specified by Westinghouse designers

• Special Investigations on Surface Effects: Paints, Coatings, Deposits (boric acid in water), etc.

ULPU-V: Three Baffle Configurations

AP1000 water inlet geometry

ULPU-V Steam Outlet

ULPU-2400

Configuration V

1152 heaters (power control)

Magnetic Flowmeter

72 thermocouples

7 pressure transducers

Flow visualization

ULPU-V Reference Data for AP1000 IVR Conditions