Oct. 29, 2009

Kim, Han Gon

1

Development of Passive Aux. Feedwater System in ALWR in Korea

CONTEN TS

Ⅱ. Design of PAFSⅡ. Design of PAFS

Ⅰ. IntroductionⅠ. Introduction

Ⅲ. Preliminary AnalysisⅢ. Preliminary Analysis

Ⅳ. Separate Effect TestsⅣ. Separate Effect Tests

Ⅴ. Integral Effect TestsⅤ. Integral Effect Tests

Ⅵ. Future PlanⅥ. Future Plan

Introduction

Function of Aux. Feedwater System

Feeding water to SGs when normal feedwater is lost

Safety grade heat sink to remove residual heat from the reactor core

•

2 ×

100 % motor driven pumps,

•

2 ×

100 % turbine driven pumps

•

2 ×

100% dedicated auxiliary feedwater tanks

Introduction

Passive AFWS (PAFS)

Replacing current AFWS

No active components to cool SGs

Sufficient capacity to cover all design bases accidents

Design concept

Closed loop (MS line

Hx

MF line)

PAFS HX

Inside : Saturated steam

Outside : water pool

Driving force : Gravity + Natural Circulation + Condensation

Introduction

Major T/H Phenomena to be concerned

Steam condensation inside tube

Condensation HTC and flow regime

Natural circulation inside pool

Pool boiling inside pool

Non-condensable gas effect

Water hammering

Flow instability

Design of PAFS

Design Requirements

It has to remove the residual heat of core in case of DBA postulated SGs’

cool-down

The capacity of PAFS covers at least 8 hours hot shutdown operation without any operator action in case of SBO in order to prevent the core damage

All the power source is to be eliminated except the Class 1E DC

Design of PAFS

Design of Heat Exchanger

4 bundles consist of horizontally 62 U-tubes

Tube

ID : 44.8mm

OD : 50.8mm

Inclined angle: 3 °

Tube pitch : 114mm (Min.)

Header Diameter : 30”

Design of PAFS

Design of System

Composed of 2 independent trains (100% performance)

Isolation valves& check vales

Heat exchanger

Condensation tank

Piping

System description

PAFS piping of steam feed line start from the main steam line downstream of MSIVs

Steam is condensed in heat exchanger

Condensed water goes through the return line and finally merges into an economizer line

Preliminary Performance Analysis

Purposes

To make initial sizing of HXs and system configuration

To get intuition for experiments

Tools

Best-estimate T/H code (MARS and RELAP5/Mod3.3]

Event

Loss of main feedwater accident for APR1400

Assumption

No operator action during an accident

Single failure : one PAFS valve open fail

Preliminary Performance Analysis

APR1400 modeling

2-Loop PWR (One RV, 2 SGs, 4 RCPs, 1 Przr)

C790

C778 C780

C770 C760

C704

C706

C710

J705

J707

C720

12

3

C750 5

4

32

1

C440

12

3

45

6789

10

1112

from C704

C73012 C 72 4

C7 40

1

2

C450 C430

C4611

2

C4601

2 3 4 5

RCP-B1

C470 C475 C480 C490 C495

C420 C410

C40012

3 4 5

RCP-B2

C471 C476 C481 C491 C496

C695

C690

C680

C660

C678

C670

C610C650

123

4

5

C340

12

3

456 7

89

10

1112

fro m C6 04

C604

C606

J605

J607

C620

12

3

21

C630

C330 C350

C 62 41

2C6 40

C500 1234

5

C3611

2345

RCP-A2

C371C376C381C391C396

C3601

2345

RCP-A1

C370C375C380C390C395

C3001 2 C310 C320

Loop B Loop A

C820 C821

MSSVs MSSVs

BREAKS

C596 C598

C597 C599

(M/AFW) (M/AFW)

C822

C 935

C520

C 51 0

12

3

4

567

89

10

J5 05

C589

J562C932 C485

J563C933 C486

C5 76C 57 3 C5 72C 57 7

J566

J567

J560 C930C385

J561 C931C386

C5 74C 57 1C5 70C 57 5

J564

J565

VolumeTime-Dependent Volume

Valve JunctionJunction

All the Heat Structures are Modeled.

sj58 8

v6 91 v6 92 v6 93v79 1v7 92v7 9 3

C170-1

-2

-3

-4

C190

C200

C210

160C C150

-1

-2

-3

C245

C220-20-19

-1

-2

C 230

-19

-2

-1

::

::

C250

C260

C270-1-2-3

C280-4

C290

C140 -3-2-1

C110

C130-3-2-1-4

-3

-4

-5

-1

-2

-3

-4

-5

C180

-2

-1

C120

-3

-2

-1

C 240

C825 C823C824

SV800

v80 5

C795

TV8 10TV8 20

MSSVsv77 1v7 72v7 7 3

C835 C834

C775

C833

C675

C830 C831MSSVs

C832

v6 71 v6 72 v6 73

P SC SA

(intact)

P SC SB(fail)

C790

C778 C780

C770 C760

C704

C706

C710

J705

J707

C720

12

3

C750 5

4

32

1

C440

12

3

45

6789

10

1112

from C704

C73012 C 72 4

C7 40

1

2

C450 C430

C4611

2

C4601

2 3 4 5

RCP-B1

C470 C475 C480 C490 C495

C420 C410

C40012

3 4 5

RCP-B2

C471 C476 C481 C491 C496

C695

C690

C680

C660

C678

C670

C610C650

123

4

5

C340

12

3

456 7

89

10

1112

fro m C6 04

C604

C606

J605

J607

C620

12

3

21

C630

C330 C350

C 62 41

2C6 40

C500 1234

5

C3611

2345

RCP-A2

C371C376C381C391C396

C3601

2345

RCP-A1

C370C375C380C390C395

C3001 2 C310 C320

Loop B Loop A

C820 C821

MSSVs MSSVs

BREAKS

C596 C598

C597 C599

(M/AFW) (M/AFW)

C822

C 935

C520

C 51 0

12

3

4

567

89

10

J5 05

C589

J562C932 C485

J563C933 C486

C5 76C 57 3 C5 72C 57 7

J566

J567

J560 C930C385

J561 C931C386

C5 74C 57 1C5 70C 57 5

J564

J565

VolumeTime-Dependent Volume

Valve JunctionJunction

All the Heat Structures are Modeled.

sj58 8

v6 91 v6 92 v6 93v79 1v7 92v7 9 3

C170-1

-2

-3

-4

C190

C200

C210

160C C150

-1

-2

-3

C245

C220-20-19

-1

-2

C 230

-19

-2

-1

::

::

C250

C260

C270-1-2-3

C280-4

C290

C140 -3-2-1

C110

C130-3-2-1-4

-3

-4

-5

-1

-2

-3

-4

-5

C180

-2

-1

C120

-3

-2

-1

C 240

C825 C823C824

SV800

v80 5

C795

TV8 10TV8 20

MSSVsv77 1v7 72v7 7 3

C835 C834

C775

C833

C675

C830 C831MSSVs

C832

v6 71 v6 72 v6 73

P SC SA

(intact)

P SC SB(fail)

Preliminary Performance Analysis

Preliminary Performance Analysis

S/G Water LevelS/G Water Level Heat Transfer at S/G Secondary SideHeat Transfer at S/G Secondary Side

0.1 1 10 100 1000 10000

20

30

40

50

60

70

80

90

Wat

er L

evel

(%,W

R)

time(sec)

S/G Water Level

0.1 1 10 100 1000 10000

0

500

1000

1500

2000

Pow

er(M

W)

time(sec)

Heat Transfer Rate

Preliminary Performance Analysis

Steam and Water Mass Flow of PAFSSteam and Water Mass Flow of PAFS

0.1 1 10 100 1000 10000-300

-250

-200

-150

-100

-50

0

50

100

150

200

250

300

Mas

s Fl

ow(k

g/s)

time(sec)

mflowj (325000000) mflowj (525000000)

Temp. at Pool BottomTemp. at Pool Bottom

0 2000 4000 6000 8000 10000

300

310

320

330

340

350

360

370

380

390

Tem

pera

ture

(K)

time(sec)

tempf (810010000)

Preliminary Performance Analysis

Temp. at PCHX TubeTemp. at PCHX Tube

0 2000 4000 6000 8000 10000

300

350

400

450

500

550

Tem

pera

ture

(K)

time(sec)

tempf (420010000) tempf (450050000)

PCHX Tube Void FractionPCHX Tube Void Fraction

0 2000 4000 6000 8000 10000

0.0

0.2

0.4

0.6

0.8

1.0

Voi

d Fr

actio

ntime(sec)

voidg (430010000) voidg (450100000)

Separate Effect Tests (SET)

Purposes

To measure condensation HTC

To identify flow regime along the tube

To identify non-condensable gas effect

To measure natural circulation capability in the pool

To measure flow instability

Characteristics of the facility

Scaling : 1/124 volume scale (full height)

Water pool : conserve geometric shape

HX tubes : 1/1 area and length, 1/124 # of tubes

Separate Effect Tests

Test facility

Steam Generator (SG)

100 bar, 1.5MW Heat Generation

PAFS Tank

Full height, reduced area

SG Pressure Control Sys.

Exhausted Steam Dump Sys

PAFS Tank Filling and Heating Sys.

Initial De-gassing Sys.

Separate Effect Tests

Measurement system

PAFS Tank

130 Thermo-couples to measure natural circulation

130 void fraction sensors and visual windows

Separate Effect Tests

Phase 1A measurement

Total heat removal rate

Average HTC

Temp. distribution inside/outside tube

Wall temp.

Pressure loss at tube/system

Phase 1B measurement

Phase 1A measurement

Local HTC

Separate Effect Tests

Phase 2 measurement

Flow regime

Integral Effect Tests

Purpose

Overall performance

System instability

APR1400

1,450MWe Advanced PWR

2-Loop PWR

ITL for APR1400

ATLAS (Advanced Test Loop for Accident Simulation)

Volume scale : 1/288

Area scale : 1/144

Height scale : ½

Design P/T : 18.7Mpa/370oC

Max. Core power : 2MW

Integral Effect Tests

IET using ATLAS

PAFS at one SG

Height scale : ½

Water pool : ATLAS scale

Steam line : pressure drop scale

Water line : pressure drop and volume scale

HXs

Conserve condensation HTC and flow regime

Local scaling

Current Status and Future Plan

‘07 ‘08 ‘09 ‘10 ‘11 ‘12

DesignBasic Design

Detail Design

Analysis

Preliminary analysis

Safety analysis

TestSET

IET

Current