ML20073K031
| ML20073K031 | |
| Person / Time | |
|---|---|
| Site: | 05200003 |
| Issue date: | 09/30/1994 |
| From: | Stephen Bajorek, Hochreiter L, Matt Young WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| To: | |
| Shared Package | |
| ML19304C610 | List: |
| References | |
| WCAP-14172, NUDOCS 9410070268 | |
| Download: ML20073K031 (195) | |
Text
_
M!
.a as.,_M,.. eilft, ,
L q
t W
NE. g"MEO 1
- g. ; ,_ a-- , i f.
~
! I :-
g .
j D11N! bMfnMPs,.
43pa mamm4 j i I i
{ngak kEkbN FA i s-k.w. .
mes RRE i ,
Nsll 7_ 7 m_,._.i Ylillium n me
", i g(e!N E PP p
!gg an islim am 0 N1 g ;:;
,] !
pgi%g g- a w@'j[ J u n'
,hk. kha '
4 I ti , '.: ' l l
.e u a'm pO i. 1 i kb N EN 3 fm $$hha m y_____
..g i nsia au s a rc y m -
y g [
m EmnJA=-n-
_ _]_'-_
ge db j in r es;O Mrgre M gi g itra- -
pin g
-~~
,j. [Q<ifEg = --m
==
_, 4%B M Mi sa_
, , , , , , . , , . , ,. X< . , ,' g/ -'. , ' ~.
l 't% . .
e > ,
+ e t
.. ~ ,
m -
-2 c %
.' 4
- .m6, ;.,. ',
'P
' t
- a. )
. Y h - Westinghouse Non-Proprietary Class 3t J '1
" ./* I 4 I
.t t -i
. c ,
9-
').,
+ ' . A.
/
,'^.Uf -
, f -'l '
J'
' . * - _ i a
>.y
,'s .
?
-d c
. .. y c '..
t.
i 3' A
.'u:.y
-, Jv
,. n y..
,a. :n rn
~ ;
y-. __
, .y s
- 1 s- r. 3 i
4.'
( .w ej t ..
> 't.
'" y e 4 m
'f
{ t f
.,. p'g /,',-
r
.~
5 eJ L' {.
I
]
?._ ll ,
.[ y< c h j Y.
n i y L-s 'g,.- '
' 44.4 m.
k 3 ,
4 v
E
- e E.,
,-,j. e .
y l , :Nh
+ , i l)' I -'.)
Y f ;
f., k / u$
4 1 /
- <4
'If j 3 f t .'.g
%,j .
ry,. s -
l +f.
y 9 - .
{}-
q
.y S
i , v . $
- a. = %
.--y.
1
.. i
.n u <
- - ..-2 a
,, - ' r. (,
- r
);
c
. . 'e '
- .[f
,b. , - ~,
e..'
- s >. -1.1.m,'r.
'+%.! 3 -. g. j-c.- , ,p g og
, ,,p<
e c'[
V -, g
- 9. ..
.lg , . L.'(
a
, y4 rp y
- ;,q D;,J, e
~ v., I.a,s.eJs, . ' '..
. a ,,. u.1 ,, -
e mQf.
. _. s , ..
.a <
i
.a
...,.j M
'e$.g i
, .qm E
w .' - g
+
+
- d. 'p
, .c u .-
% . qf
, ,f W
~
- - . ij m.
Y s' i
- .'g ( 4 g y y ,,.g
.. 3. ; s - #,
..as -
a 3 1; - ,. . .j i 3 lNN {; ,
_S,f ji, .
,3 s ~Y.n'.} .4, (-;- . n ew -o
, w.a v.s. -< rs - p:.' -cm m. tv' g y
s.:-., - <
' la
-__ . ~ >
WESENCHOLSE NoSPROPRIETARY CLASS 3 i
+
r i
WCOBRA/ TRAC APPLICABILITY ,
TO AP600 LARGE-BREAK.
LOSS-OF-COOLANT ACCIDENT
.i i
i L. E. Hochreiter S. M. Bajorek ,
M. Y. Young i
September 1994 l
l l
WESTINGHOUSE ELEC1RIC CORPORATION ;
1 Nuclear Technology Division P. O. Box 355 )
i- Pittsburgh, Pennsylvania 15230-355 l I
1 01994 Westingbouse Electnc Comoration All Rights Resened 1
t n:\l410w.wpf:lb-093094 I
t I
I
-r , n e e -- w.- -
I i
AP600 DOCUMENT COVER SHEET TDC: IDS: I S j
Form 58202G(5/94)[uA1194w.0.wpf.1b] AP600'CENTRAL FILE USE ONL :
0058.FRM RFSe: RFS ITEM #:
AP600 DOCUMENT No. REVISION NO. ASSIGNED 10 RCS-GSR-001 Page 1 of__
ALTERNATE DOCUMENT NUMBER: WCAP 14172 & 14171 WORK BREAKDOWN #: 3.1.1.9.1 DESIGN AGENT ORGANIZATION:
TITLE: WCOBRAffRAC Applicability to AP600 Large-Break Loss-of-Coolant Accident ATTACHMENTS: DCP #/REV, INCORPORATED IN THIS DOCUMENT REVISION:
CALCULATION / ANALYSIS
REFERENCE:
i ELECTRONIC FILENAME ELECTRONIC FILE FORMAT ELECTRONIC FILE DESCRIPTION 1410w-0.wpf Word Perfect (C) WESTINGHOUSE ELECTRIC CORPORATION 199L ,
D WESTINGHOUSE PROPRIETARY CLASS 2 This document contains information propnetary to Westinghouse Electne Corporation; it is submitted in confidence and is to be used solely for the purpose for which it is fumished and retumed upon request. This document and such information is not to be reptorjuced, transmitted, disclosed or used otherwise in whole or in part without prior written authorization of Wesbnghouse Electric Corporation, Energy Systems Business Unit, subject to the legends wntained hereof.
O WESTINGHOUSE PROPRIETARY CLASS 2C This document is the property of and contains Proprietary information owned by Westinghouse Electric Corporation and/or its subcontractors and suppliers. It is transmitted to you in confidence and trust, and you agree to treat this document in strict accordance with the terms and condbons of the agreemer.1 under which it was provided to you.
@ WESTINGHOUSE CLASS 3 (NON PROPRIETARY)
COMPLETE 1 IF WORK PERFORMED UNDER DESIGN CERTIFICATION ~OR COMPLETE 2 IF WORK PERFORMED UNDER FOAKE. ,
1 @ DOE DESIGN CERTIFICATION PROGRAM - GOVERNMENT LIMITED RIGHTS STATEMENT ISee page 2)
Copyright statement A liwnse is reserved to the U.S. Govemment under mntract DE-ACO340SF18495.
O DOE CONTRACT DELIVERABLES (DELIVERED DATA)
Subject to specified excephons, disclosure of this data is restricted until September 30,1995 or Design Certification under DOE contract DE-ACO3-90SF18495, whichever is lator.
EPRI CONFIDENTIAL: NOTICE; 10 2 3 4 5 CATEGORY: A LCCODDEDF 2 O ARC FOAKE PROGRAM - ARC LIMITED RIGHTS STATEMENT ISee page 21 Copyright statement A license is reserved to the U.S. Govemment under contract DE-FCO2-NE34267 and subcontract ARC-93 3-SC-001.
O ARC CONTRACT DELIVERABLES (CONTRACT DATA)
Subject to specified exceptions, disclosure of this data is restricted under ARC Subcontract ARC-93-3-SC-001. !
ORIGINATOR SIGNA E/DATE i L. E. Hochreiter AP600 RESPONSIBLE MANAGER j ((
SIGf' TO E*
g J/g 7MfAPPROV L DATE
{
E. H. Novendstem _ % y 1J 7 ,
' Approval of the responsible manager signsbes that occument is complete, all regaired reviews are complete, electronic file is attached and document is 1 seleased for use.
i AP600 DOCUMENT COVER SHEET Page 2 Form &B202G(5t94) LIMITED RIGHTS STATEMENTS DOE GOVERNMENT LIMITED RIGHTS STATEMENT (A) These data are submitted with hmited rights under govemrnent contract No. DE-ACO3-90SFt8495. These data may be reproduced and used by the government with the express limitation that they will not, without written permission of the contractor, be used for purposes of manufacturer not dsclosed outside the govemment; except that the govemment may dsclose these data outside the govemment for the following purposes, if any, provided that the govemment tnakes such disdosure subject to prohibibon against further use and disclosure:
(1) This
- Proprietary Data
- may be disclosed for evaluatson purposes under the restrictions above.
(II) The 'Propnetary Data
- may be disclosed to the Electne Power Research inst %te (EPRI), electnc utihty representatives and their direct consultants, exduding drect commercial competitors, and the DOE National Laboratones under the prohibitons and restnctions above.
(B) This notice shall be marked on any reproducton of these data, in whole or in part.
ARC i.!MITED RIGHTS STATEMENT:
This proprietary data, fumished under Subcontract Number ARC-93-3-SC 001 with ARC rnay be duplicated and used by the govemment and ARC, subject to the limitations of Arbde H-17.F. of that subcontract, with the express hmitations that the proprietary data may not be disdosed outside the govemment or ARC, or ARC's Class 1 & 3 members or EPRI or be used for purposes of manufacture without prior permission of the Subcontractor, except that further disclosure or use may be made solely for tre following purposes:
This propnetary data may be disclosed to other than commercial cornpetitors of Subcontractor for evaluation purposes of this subcontract under the restnction that the propnetary cata be retaineo in confidence and not be further dsclosed, and subject to the terms of a non-disclosure agreement between the Subcontractor and that organization, exduding DOE and its contractors.
DEFINITIONS CONTRACTIDELIVERED DATA - Consists of documents (e.g. specifications, drawings, reports) which are generated under the DOE or ARC contracts which contain no background proprietary data.
EPRI CONFIDENTIALITY / OBLIGATIONNOTICES NOTICE 1: The data in this document is subject to no confidentality obligations.
NOTICE 2: The data in this document is proprietary and confidential to Westinghouse Electne Corporation and/or its Contractors. It is forwarded to recipient under an obhgation of Confidence and Trust for hmited purposes only. Any use, dsclosure to unauthorized persons, or copying of this document or parts thereof is prohibited except as agreed to in advance by the Electne Power Research Insttute (EPRI) and Westinghouse Electne Corporation. Recipient of this data has a duty to mquire of EPRI andor Westinghouse as to the uses of the informaton contained herein that are permitted.
NOTICE 3: %e data in this document is propnetary and confidential to Westinghouse Eiectric Corporation and/or its Contractors. It is forwarded to recipent under an obligation of Confidonce and Trust for use onty in evaluation tasks specificalty authonzed by the Electric Power Research Insttute advance by (EPRI)RI EP and West nghouse Electne Corporaton. Recipient of this data has a duty to inquire of EPRI and/or Westi uses of the information contained herein that are permitted. This document and any copies or excerpts thereof that may have been generated are to be retumed to Westnghouse, directly or through EPRI, when requested to do so.
NOTICE 4: The data in this document is proprietary and confidential to Westinghouse Esectric Corporation and/or its Contractors. It is being revealed in contdence and trust only to Employees of EPRI and to certain contractors of EPRI for limited evaluation tasks authorized by EPRL Ariy use, dsclosure to unauthonzed persons, or copying of this document or parts thereof is prohibited. This Document and any copies or excerpts thereof that may have been generated are to be retumed to Westinghouse, directly or through EPRI, when requested to do so.
NOTICE 5: De data in this document is proprietary and confidential to Westinghouse Electric Co poration ansor its Contractors. Access to this data is given in Confidence and Trust only at Westinghouse facilities for limited evaluation tasks assigned by EPRt. Any use, disdosure to unauthonzed persons, or copying of this document or parts thereof is prohibited. Neither this document nor any excerpts therefrom are to be removed from Westinghouse facilities.
EPRI CONFIDENTIALITY / OBLIGATION CATEGORIES CATEGORY 'A'-(See Delivered Data) Consists of CONTRACTOR Foreground Data that is contained in an issued reported.
CATEGORY *B" - (See Delivered Data) Consists of CONTRACTOR Fcreground Data that is not contained in an issued report, except for computer programs.
CATEGORY *C"- Consists of CONTRACTOR Background Data except for computer programs.
CATEGORY 'D'- Consists of computer programs developed in the course of performing the Work.
CATEGORY *E"- Consists of computer programs developed pnor to the Effective Date or after the Effective Date but outside the scope of the Work.
CATEGORY *F'- Consists of administratve plans and administrative reports.
1
l TABLE OF CONTENTS Title Page Section
SUMMARY
I 1.0 INTRODUCEON 1-1
2.0 DESCRIPTION
OF THE AP600 LARGE-BREAK LOCA TRANSIENT 2-1 2.1 Large-Break LOCA Phenomena importance Ranking Table (PIRT) 2-1 2.2 Comparisons of the Large-Break LOCA Transient for Current PWRs and AP600 2-10 2.3 Conclusions 2-53 3.0 SPECIFIC WCOBRATTRAC VALIDATION FOR UNIQUE AP600 FEATURES 3-1 3.1 CCTF Validation with Direct Vessel Injection 3-1 3.2 UPTF WCOBRA/ TRAC Validation 3-63 3.3 Conclusions 3-112 APPLICATION OF THE WCOBRA/ TRAC CODE UNCERTAINTY TO THE AP600 4-1 4.0 4.1 Application of the CQD Uncertainty to the AP600 Large-Break LOCA Calculation 4-1 4.2 AP600 Large-Break LOCA 95th Percentile PCT 4-9
5.0 CONCLUSION
S 5-1
6.0 REFERENCES
6-1 u:\l410w.w3d IM192844 iii
l LIST OF TABLES i
Table Page 1-1 AP600 Passive Safety System Components 1-3 1-2 Assessmetit of the AP600 Large-Break LOCA Processes 1-4 2.1-1 Component and Phenomena Hierarchy during LBLOCA Blowdown 2-3 2.1-2 Summary of Expert Rankings and AHP-Calculated Results 2-6 2.1-3 Component and Phenomena Hierarchy during LBLOCA Blowdown, Modified for AP600 Design 2-7 2.2-1 North Anna (VRA) Initial and Boundary Conditions 2-18 2.2-2 AP600 Conditions for the Large-Break LOCA Superbounded Case 2-19 3.1-1 Component Dimensions of CCTF Compared to PWR 3-10 3.1-2 CCTF Test Conditions 3-11 3.1-3 CCTF Rod-to-Channel Connections 3-11 l 3.1-4 Nominal Steam and ECCS Injection Rates 3-12 4.1-1 Test Grouping for Different Peak Cladding Temperatures 4-4 4.1-2 Calculation of 3' COBRA / TRAC Code Uncertainty - Blowdown PCT 4-4 4.1-3 Calculation of }V_COBRATTRAC Code Uncertainty - Rellood PCT 4-5 4.2-1 AP600 Large-Break LOCA Break Specuum Peak Cladding Temperature (PCT) Results 4-11 I
u A1410w.wyt ttw092844 jv
LIST OF FIGURES Ficure Pace 1-1 AP600 Passive Safety injection System 1-7 2.2-1 North Anna (VRA) Vessel Drawing 2-20 2.2-2 VRA WCOBRA/ TRAC Vessel Model Noding 2-21 2.2-3 VRA Vessel Cross Section Noding 2-22 2.2-4 VRA Loop Noding 2-23 2.2-5 VRA System Pressure 2-24 2.2-6 VRA Peak Cladding Temperature 2-25 2.2-7 VRA Cladding Temperature at Different Elevations 2-26 2.2-8 VRA Hot Rod Cladding Temperature at Several Points during the Transient 2-27 2.2-9 Continuous Liquid Flowrate at Top and Bottom of Hot Channel during Blowdown 2-28 2.2-10 Continuous Liquid Flowrate at Top and Bottom of Average Charmel Adjacent to Hot Channel During Blowdown 2-29 2.2-11 Collapsed Liquid Level in Downcomer 2-30 2.2-12 Collapsed Liquid Level in Core 2-31 2.2-13 AP600 Vessel Schematic 2-32 2.2-14 AP600 WCOBRA/ TRAC Vessel Noding 2-33 2.2-15 AP600 Section 4 Noding 2-34 2.2-16 AP600 Loop Noding 2-35 2.2-17 WCOBRA/ TRAC AP600 Primary Pressure for the Co=0.8 DECLG Break 2-36 2.2-18 Co=0.8 DECLG Blowdown, Top of Core Flow, Hot Assembly Channel 2-37 2.2-19 Co=0.8 DECLG Transient, Accumulator Flow Rate From One Tank 2-38 2.2-20 Core Makeup Tank Flow for Co=0.8 DECLG Break 2-39 2.2-21 Co=0.8 DECLG Blowdown, PCT at 8.5 Ft. Elevation, Rods 1 thru 5 2 40 2.2-22 Co=0.8 DECLG Blowdown, PCT at 6.0 Ft. Elevation, Rods 1 thru 5 2-41 2.2-23 Co=0.8 DECLG Blowdown, PCT at 10 0 Ft. Elevation, Rods I thru 5 2-42 2.2-24 Co=0.8 DECLG Blowdown, Top of Core Flow, Guide Tube Channel 2-43 2.2-25 Co=0.8 DECLG Blowdown, Top of Core Flow, Open Hole / Support Column Channel 2-44 2.2-26 Co=0.8 DECLG Blowdown, Top of Core Flow, Peripheral Channel 2-45 2.2-27 Co=0.8 DECLG Transient, Core Void Fraction Hot Assembly Bottom, Midplane, Top 2-46 2.2-28 Co=0.8 DECLG Transient, Lower Plenum Liquid Level From Vessel Bottom to Bottom of Active Fuel 2-47 2.2-29 Co=0.8 DECLG Transient, Downcomer Liquid Level From Bottom of Annulus 2-48 2.2-30 Co=0.8 DECLG Transient, Core Hot Assembly Liquid Level 2-49 2.2-31 Co=0.8 DECLG Transient, PCT at 6.0 Ft. Elevation, Rods 1 thru 5 2-50 2.2-32 Co=0.8 DECLG Transient, PCT at 8.5 Ft. Elevation, Rods 1 thru 5 2-51 2.2-33 Co=0.8 DECLG Transient, PCT at 10.0 Ft. Elevation, Rods 1 thru 5 2-52 u:\1410w wpf.lb-0GM v i
LIST OF FIGURES (Cont.)
Ficure P_ a.ge 3.1-1 CCTF Core-II Test Facility 3-13 i
3.1-2 Diagram of CCTF Pressure Vessel 3-14 3.1-3a Cross Section of CCTF Pressure Vessel 3-15 3.1-3b Cross Section of CCTF Upper Plenum 3-15 3.1-4 Axial Power Profile of Heated Rods in CCTF Core 3-16 3.1-5 Test Sequence of Test C2-AA2 (Run 58) 3-17 3.1-6 WCOBRA/ TRAC CCTF Vessel Noding - Plan View 3-18 3.1-7 WCOBRA/ TRAC CCTF Lower Plenum Noding (Section 1) 3-19 5
3.1-8 WCOBRA/ TRAC CCTF Core Region Noding (Section 2) 3-20 3.1-9 WCOBRA/ TRAC CCTF Tie-Plate Region Noding (Section 3) 3-21 3.1-10 WCOBRA/ TRAC CCTF Upper Plenum Region Noding (Section 4) 3-22 3.1-11 WCOBRA/ TRAC CCTF Upper Plenum Region Noding (Section 5) 3-23 3.1-12 WCOBRAfrRAC CCTF Loop Connection Region Noding (Section 6) 3-24 3.1-13 WCOBRATTRAC CCTF Upper IIcad Region Noding (Section 7) 3-25 3.1-14 WCOBRATTRAC CCTF Downcomer Channel Arrangement 3-26 3.1-15 .W.' COBRA / TRAC CCTF Loop Noding Diagram 3-27 3.1-16 CCTF Run 58, Low-Powered Rod, Clad Temperature at 1.25 ft. 3-28 3.1-17 CCTF Run 58, Low-Powered Rod, Clad Temperature at 3.33 ft. 3-29 3.1-18 CCTF Run 58, Low-Powered Rod, Clad Temperature at 6 ft. 3-30 3.1-19 CCTF Run 58, Low-Powered Rod, Clad Temperature at 8 ft. 3-31 3.1-20 CCTF Run 58, Low-Powered Rod, Clad Temperature at 10 ft. 3-32 3.1-21 CCFF Run 58, Medium-Powered Rod, Clad Temperature at 1.25 ft. 3-33 .
3.1-22 CCTF Run 58, Medium-Powered Rod, Clad Temperature at 3.33 ft. 3-34 3.1-23 CCTF Run 58, Medium-Powered Rod, Clad Temperature at 6 ft. 3-35 3.1-24 CCTF Run 58, Medium-Powered Rod, Clad Temperature 8 ft. 3-36 3.1-25 CCTF Run 58, Medium-Powered Rod, Clad Temperature at 10 ft. 3-37 3.1-26 CCTF Run 58, liigh-Powered Rod, Clad Temperature at 1.25 ft. 3-38 3.1-27 CCTF Run 58, liigh-Powered Rod, Clad Temperature at 3.33 ft. 3-39 3.1-28 CCTF Run 58, High-Powered Rod, Clad Temperature at 6 ft. 3-40 3.1-29 CCTF Run 58, High-Powered Rod, Clad Temperature at 8 ft. 3-41 3.1-30 CCTF Run 58, High-Powered Rod, Clad Temperature at 10 ft. 3-42 3.1-31 CCTF Run 58, Quench Envelope - Low-Powered Rod 3-43 3.1-32 CCTF Run 58, Quench Envelope - Medium-Powered Rod 3-44 3.1-33 CCTF Run 58, Quench Envelope - High-Powered Rod 3-45 3.1-34 CCTF Run 58, Upper Plenum Pressure 3-46 3.1-35 CCTF Run 58 Downcomer Differential Pressure 3-47 3.1-36 CCTF Run 58, Core Differential Pressure 3-48 3.1-37 CCTF Run 58, Upper Plenum to Containment Differential Pressure 3-49 3.1-38 CCTF Run 58, Loop 1 Pump Simulator Differential Pressure 3-50 3.1-39 CCTF Run 58. Loop 4 Pump Simulator Differential Pressure 3-51 f
uA1410w *Tf :lb-o92894 Vi
LIST OF FIGURES (Cont.)
Figure Pace 3.1-40 CCTF Run 58, Loop 1 Cold Leg Water Mass Flow 3-52 3.1-41 CCTF Run 58, Loop 1 Cold Leg Steam Mass Flow 3 53 3.1-42 CCTF Run 58, Loop 4 Cold Leg Water Mass Flow 3-54 3.1-43 CCTF Run 58, Loop 4 Cold Leg Steam Mass Flow 3-55 3.1-44 CCTF Run 58, Loop 1 Hot Leg Water Mass Flow 3-56 3.1-45 CCTF Run 58, Loop 1 Hot Leg Steam Mass Flow 3-57 3.1-46 CCTF Run 58, Loop 4 Hot Leg Water Mass Flow 3-58 3.1-47 CCTF Run 58, Loop 4 Hot Leg Steam Mass Flow 3-59 3.1-48 CCTF Run 58, Pressure Vessel Side, Loop 4 Cold Leg Fluid Temperature 3-60 3.1-49 CCTF Run 58, Loop 4 Hot Leg Fluid Temperature 3-61 3.1-50 CCTF Run 58, Loop 4 Seal Fluid Temperature 3-62 3.2-1 UPTF Test Vessel and Internals 3-73 3.2-2 UPTF Upper Plenum Structure 3-74 3.2-3 UPTFnummy Fuel Assembly and End Box with Flow Restrictor (A) or Spider (B) 3-75 3.2-4 UPTF Core Simulator injection Assembly 3-76 3.2-5 UPTF Steam Generator Simulators and Water Separators 3-77 3.2-6 UPTF Configuration for Test 21 3-78 3.2-7 Steam and Water Injection in UPTF Test 21 3-79 3.2-8 WCOBRA/ TRAC UI'TF Vessel Noding - Plan View 3-80 3.2-9 WCOBRA/ TRAC UPTF Vessel Sections 1 and 2 3-81 3-82 3.2-10 .3'COBRATTRAC UPTF Vessel Sections 3 and 4 3.2-11 WCOBRA/ TRAC UPTF Vessel Sections 5 and 6 3-83 3.2-12 WCOBRATTRAC UPTF Vessel Sections 7 and 8 3-84 3.2-13 WCOBRATTRAC UPTF Intact Loop Noding 3-85 3.2-14 WCOBRA/ TRAC UPTF Broken Loop Noding 3-86 ,
3.2-15 WCOBRA/ TRAC UPTF Downcomer Injection Noding 3-87 ;
3.2-16 UPTF Test 21 Phase A, Lower Plenum Mass Inventory 3-88 3.2-17 UPTF Test 21 Phase A, Broken Cold Leg Steam Mass Flow 3-89 !
3-90 l 3.2-18 UPTF Test 21 Phase A, Broken Cold Leg Mixture Mass Flow 3.2-19 UPTF Test 21 Phase A, Broken Cold Leg Integrated Mixture Mass Flow 3-91 3.2-20 UPTF Test 21 Phase A, Downcomer Pressure 3-92 3.2-21 UPTF Test 21 Phase A, Downcomer Collapsed Liquid Level 3-93 3.2-22 UPTF Test 21 Phase A, Downcomer Mass Flow Above Bottom of Core Barrel 3-94 3.2-23 UPTF Test 21 Phase A, Intact Cold Leg Mass Inventories 3-95 !
3.2-24 UPTF Test 21 Phase B 1, Lower Plenum Mass Inventory 3-96 3.2-25 UPTF Test 21 Phase B I, Broken Cold Leg Steam Mass Flow 3-97 !
3.2-26 UPTF Test 21 Phase B I, Broken Cold Leg Mixture Mass Flow 3-98 3.2-27 UPTF Test 21 Phase B I, Broken Cold Leg Integrated Mixture Mass Flow 3-99 3.2-28 UPTF Test 21 Phase B I, Downcomer Pressure 3-100 wu 4 tow.wpr.wo9m4 vil
LIST OF FIGURES (Cont.)
Fjgitre Page 3.2-29 UPTF Test 21 Phase B I, Downcomer Collapsed Liquid Level 3-101 3.2-30 UPTF Test 21 Phase B I, Downcomer Mass Flow Just Above Bonom of Core Barrel 3-102 3.2-31 UPTF Test 21 Phase B I, Intact Cold Leg Mass Inventories 3-103 3.2-32 UPTF Test 21 Phases B II & III, Lower Plenum Mass inventory 3-104 3.2-33 UPTF Test 21 Phases B II & III, Broken Cold Leg Steam Mass Flow 3-105 3.2-34 UPTF Test 21 Phases B II & III, Broken Cold Leg Mixture Mass Flow 3-106 3.2-35 UPTF Test 21 Phases B II & III, Broken Cold Leg Integrated Mixture Mass Flow 3-107 3.2-36 UPTF Test 21 Phases B II & III, Downcomer Pressure 3-108 3.2-37 UPTF Test 21 Phases B II & 111, Downcomer Collapsed Liquid Level 3-109 3.2-38 UPTF Test 21 Phases B II & III, Downcomer Mass Flow Just Above Bottom of Core Barrel 3-110 3.2-39 UPTF Test 21 Phases B II & III, Intact Cold Leg Mass Inventories 3-111 4.1-1 Components of 3,'COBRATTRAC Code Uncertainty for Reflood PCT at 6-ft. Elevation 4-6 4.1-2 Average Code Bias and Uncertainty for Blowdown 4-7 4.1-3 Average Code Bias and Uncertainty for Reflood 4-8 u A1410w3pf;1b-092804 Vili
SUMMARY
The 3' COBRA / TRAC-Mod 7 code is a general systems analysis code with the capability to model and analyze thermal-hydraulic transients in pressurized water reactors. Westinghouse three- and four-loop operating plants have been analyzed with this version of the code. An earlier version of the code has been licensed and used to analyze large-break LOCA transients in two-loop pressurized water reactors equipped with upper plenum safety injection systems.
While the AP600 design has several unique features, the key thermal-hydraulic phenomena for an AP600 large-break LOCA are expected to be the same as those in a conventional operating PWR.
Therefore, the modeling methods and code validation performed in support of operating plants is directly applicable to the AP600 design.
One area that is different in the AP600 design relative to current operating Westinghouse PWRs is the use of downcomer injection of the emergency core cooling water. The accumulator, core makeup tank, in-containment water refueling storage tank, and sump recirculation injection flow enter the vessel through two opposite direct vessel injection locations. WCOBRAflRAC has been assessed using tests from two separate experimental facilities that investigated direct vessel injection to ensure that the accuracy of the code prediction for this injection mode is acceptable.
The AP600 Standard Safety Analysis Report (SSAR) calculations are shown and compared to transients for a current three-loop PWR to show that the AP600 large-break behavior is similar to that of current PWRs.
The results of this study confirm that WCOBRA/ TRAC can accurately model the AP600 large-break transient without any AP600-specific code or model modification. The results predicted by WCOBRAfrRAC for the AP600 indicate that a substantial large-break LOCA margin exists for this new design with passive safety systems.
l uAt410wagn4W2894 1
l
1.0 INTRODUCTION
The WCOBRA/ TRAC code is a generalized thermal-hydraulic systems code that has the capability to model either boiling water or pressurized water reactors (PWRs). The CGBRA portion of the code represents the reactor vessel component. The TRAC portion of the code represents the loop components, such as the steam generators, pumps, accumulators, and the associated piping. The active emergency core cooling systems (ECCSs) of the current generation PWRs are modeled as boundary conditions using pressure- and temperature <iependent tables to represent the high- and low-pressure safety injection systems. Breaks of different sizes and types, either guillotine or communicative, can also be simulated at different locations on the reactor piping. The WCOBRA/ TRAC-Mod 7 version of the code was developed and verified with the intent of satisfying the requirements of the revised Appendix K rule with regards to best estimate methods. This version of the code has been used to analyze large-break LOCAs in several operating PWRs with cold leg injection. An earlier version of the code,,WCOBRA/ TRAC-Mod 4, was approved by the NRC for use with plants with upper plenum injection systems. This version has been used to analyze several two-loop PWRs.
The WCOBRA/ TRAC code has been used successfully to model PWRs with different ECCS designs.
WCOBRA/ TRAC has been used to analyze a four-loop PWR,m which has no accumulators, and employs, instead, large-capacity, high-pressure pumps that inject vertically downward into the upper plenum to refill the reactor vessel for a large-break LOCA. Detailed upper plenum noding was used to model the safety injection flow path. Sensitivity studies were then used to quantify the uncertainty in the upper plenum modeling, and the resulting conservative upper plenum model was used.
Westinghouse two-loop PWRs also have the low-pressure emergency core cooling system (ECCS) injection flowina, into the upper plenum. The safety injection flow enters the upper plenum as horizontal jets at the same elevation as the reactor hot and cold legs. Sensitivity studies and comparisons to scaled test data validated the capability of the _WCOBRATTRAC code to model this plant configuration.
The NRC version of the COBRA / TRAC code has also been used to model Westinghouse PWRs, which utilize upper head injection ECCSs.* In this design, separate high-pressure accumulators are used to inject flow into the upper head during the blowdown phase of the transient A very detailed model of the reactor system was used to best determine the blowdown behavior to the new ECCS that was added to these plants. In addition to these unique PWR ECCS designs, WCOBRA/ TRAC has also been used to model and predict the ECCS performance of conventional three- and four-loop Westinghouse PWRs.* All the above calculations indicate that the WCOBRA/ TRAC code has the capabilities to model different classes of PWRs that utilize different ECCS designs with confidence.
The AP600 is an advanced PWR design that incorporates passive safety systems that perform the same function as the active systems on curTent PWRs. The principal difference is that natural forces, such as gravity, are used for the injection of the ECCS water into the reactor vessel, rather than active ac-powered systems, such as pumps and heat exchangers. It should be noted that only the injection um4 tow.wputsmso4 11
mode is different for the AP600. Once the emergency coolant is injected into the vessel, the flow of that coolant into the core is gravity-driven by the driving head in the downcomer the same as a current PWR. For the large-break LOCA, any excess injected flow will spill out the broken cold leg break.
Figure 1-1 shows the AP600 ECCS safety design, and Table 1-1 gives the safety function of the different passive system components used in the AP600 safety system design. De two components that are of most interest for the large-break LOCA performance of the AP600 design are the accumulators and the core makeup tanks (Chits). As indicated in Table 1-1, the Chits perform the same function as the ECCS high-pressure active pumps in existing PWR designs. The AP600 accumulators are of a similar design to current plants, except that they have a larger capacity and will discharge at a slower rate compared to existing PWRs. This results in an accumulator injection period that is greater than 120 seconds, as compared to the 45-second injection period of existing two-loop PWRs. Both the accumulator flow and the ChtT flow are injected into the vessel through separate direct vessel-injection nozzles that are located slightly below the reactor cold and hot legs. This is a different injection location than that typically used in most Westinghouse PWRs. However, Babcock and Wilcox PWRs also use direct vessel injection, as well as newer Westinghouse two-loop PWRs, such as KRSKO and ANGRA.
The key thermal-hydraulic phenomena for the large-break LOCA are given in Table 1-2, and the uniqueness of AP600 design features are assessed. The objective is to make an assessment of the design features relative to WCOBRA/ TRAC's code validation and capabilities. The first column gives the key large-break LOCA phenomena that the computer code must correctly calculate. De second column indicates if there is a uniqueness in the AP600 design relative to the phenomena for which additional verification may be needed. The third column indicates whether WCOBRA/ TRAC has been verified over a broad enough range to encompass the uniqueness of the AP600 design. The fourth column indicates what validation is available or indicates the need for a specific test to validate the code for this phenomena. There are specific comments in the last column that also indicate specific sources for code validation that can be used to assess WCOBRA/ TRAC.
Table 1-2 indicates that there are very few items that are unique for the AP600 large-break LOCA transient relative to existing plant designs. Since WCOBRA/ TRAC has already been used extensively to model the large break LOCA for existing plants, this code is applicable to assess and model the AP600 large-break LOCA transient. The unique items include direct vessel injection (or downcorner injection) and modeling the ChtTs; which is a new component for the code. Therefore, the ability of
_WCOBRAfrRAC to model direct vessel injection of the ECCS flow will be specifically addressed in this report. The relative importance of the core makeup tank behavior for the large-break LOCA will also be discussed.
va14to u g n o m 94 1-2
TAllLE 1 1 AP600 PASSIVE SAFETY SYSTEh! COMPONENTS Function Current PWRs AP600 Reactor Shutdown - control rods - control rods
- rideout (negative power - rideout (more negative power, coefficient, auxiliary feedwater, PRHR, CMT) chemical and volume control)
RCS Overpressure -
pressurizer relief - larger pressurizer
- high-pressure trip - high-pressure trip
- pressurizer safety valves - pressurizer safety valves RCS Heat Removal -
- auxiliary feedwater - auto feed / bleed manual feed / bleed (CMT/IRWST ADS)
(PZR, PORV, HHSI) - manual feed / bleed (accumulators /RNS, ADS)
High-Pressure Injecdon - charging pumps - CMT higb-head pumps - accumulator /lRWST (ADS)
- accumulator / residual heat removal (ADS)
Low-Pressure Injection -
- low-head pumps -
Long-Term Recirculation -
low-bead pumps feeding - containment sump (ADS)
- high-head pumps Containment Heat Removal - fan coolers - external air + water drain
- containment spray pumps / heat - external air only cooling exchanger uA1410w.wpf;1b-o92894 l-3 l l
5 t
?
TAHl.E 1-2
.{ ASSESSMENT OF THE AP600 LARGF-HREAK 1,0CA PROCFSSES p
S '
AP600 Uniqueness WCfr Validation At-400-Specific Does it Exist Validation Needed Comments IAJCA Process WRT W 11 ants
+ Blowdown
- Critical flow None Yes None
- Post-critical heat flux None Yes None heat transfer
. Transient critical heat flux
+ Rewetting
- Film boiling
- Structure heat transfer Yes, reflector Yes, not None Modeled by input L AP600-specific j
- Accumulator ECCS None Yes None f' bypass
- 2$ AP in loops None Yes None ,
- Stemn generator heat None Yes None transfer ;
- High-head safety Yes, CMT delivery, No Yes Very little CMT delivery i
injection behavior before PCT
- Pump 2$ behavior Yes, canned rotor No No Obtain data l r
i i
[
c f
5
?
{ TABI.E I-2 (Cont.)
ip ASSESSMENT OF Tile AP6001.ARGF BREAK 1.OCA PROCESSES I
y APM)0 Uniqueness WCfr Validation AP600-Specific I.OCA Process WRT W Plants Iks It Exist Validation Needed Comments
- Refill /Reflood
- ECCS bypass Yes, accumulator No None, use existing data UPTF, CCIF downcomer delivery in injection tests downcomer
- Non<ondensible gas None Yes None LOFT effect
- Post-critical heat flux None Yes None heat transfer
- Structure heat transfer Yes, radial reflector Not specific None Not needed, code can calculate
[
- Safety injection /high- Yes, CMT delivery No Yes No CMT delivery, during this head safety injection, in downcomer period aw-head safety injection
- Steam generator None Yes Nonc I behavior phase AP None Yes None
_j
E E
7 TABLE 12 (Cont.)
{ ASSESSMENT OF Tile AP600 LARGE-IIREAK LOCA PROCESSES h AP600 Uniqueness WC/T Validation AP600-Specific
'j l.OCA Process WRT W Plants I)oes it Exist Validation Needed Comments
- Reflood
- SillIllSI/LilSI injection Yes CMT downcomer No None, use existing data UPTF, CCTF downcomer delivery injection tests
- Accumulator behavior l_4mg-term delivery Yes, short-tenn for No Use LOFT data could use for LOFT verification. Other plant data available.
- Core heat transfer None Yes None
- Structure heat transfer Yes, reficctor Not specific Not needed LOFT test had structures typical of a PWR
?
- - SG cffects None Yes None
- Vessel /de-entrainment None Yes None
- Pump AP Yes, canned rotor Yes, other pumps None Pump is a known resistance
- _ _ ___ - ___-____ . - __ - _ ___= - _ _ - _ - __ - ______-_ _
!I{ll\ ,f,!ll(j{ ll ll lIlll1lll j
p .
u) m )2 N e2 uf kf co ao c 1 M (t A(
ek rn oa CT
) lH-
'} v
( s S p A-y Nm R uP ,
I g
_ g R. } j P '
)
2 I f s g ,
1
(
- s~ a, s,
t nT e "
r
+,ge) 2 >J' '
T g ,
, e mT Ppt r f eo-
~
S; r
o in a $( : W, C _
t nT o v
, R.
I , q
_ CT * , .
_ - r
- t ole c s p"} a ee s m ' RV u
S (
R HX RH n Ebg P
4) a e2 esp
" 4 4 Sgf r
e #E #p Dta o Sm b E 2 3
- iz r
u , t2 r
As1 (
L Nu RP l
- # # s pa H s op b $ -
P e
r om Lo C
3-M 4 1
F.
O-s e C S g )
- Da t
_ AS e,
t5$2'Eh 53- .a >7g .[3 .
. 3
- EN5?1' a ,= s i 1 1)l 1\ll(l\l l )'
2.0 DESCRIPTION
OF THE AP600 LARGE-BREAK LOCA TRANSIENT Introduction his section will show that the existing large-break LOCA Phenometa Importance Ranking Table (PIRT) that has been developed for operating PWRs is still applicable to the AP600. Also, the most limiting large-break LOCA transient for the AP600 will be presented and compared to that for cunent Westinghouse three-loop plants.
2.1 Large-Break LOCA Phenomena Importance Ranking Table (PIRT)
As part of the code scaling, applicability, and uncertainty (CSAU) work that the NRC performed,* j tables of large-break LOCA phenomena were developed, assessed, and ranked. The ranking process resulted in the development of PIRT tables that indicated which physical processes had the most important impact on the progression of the large-break LOCA transient. De PIRT tables also identified which processes were the most important for a safety analysis computer code to simulate with acceptable accuracy. Table 2.1-1 shows the PIRT tables developed by the NRC as part of peer reviews on the key large-break LOCA phenomena. Table 2.1-2 is a similar PIRT table that was developed as a summary of expert rankings for analysis of three- and four-loop operating PWRs.
Comparing these tables indicates that most, if not all, parameters are identical and have been given the same relative ranking. Rese tables form a consensus of what is important to model in the large-break LOCA.
Table 2.1-3 is a revision of Table 2.1-1, with the addition of AP600 design features and ranking the I phenomena of importance for that design, to compare to the three- and four-loop PWRs.
If the blowdown phase is examined, the key phenomena are the same between the AP600 and the operating plants with very little difference. He reactor coolant pumps in the AP600 are canned motor pumps with less inertia than the larger centrifugal pumps used in operating plants. De coast down times of the reactor coolant pumps in the AP600 are much faster than operating plants. The difference in the pump coast down is modeled by input directly in WCOBRAfrRAC and can account for different ilows in the various loops.
One difference that does exist between the large-break LOCA PIRT for the existing PWRs and the AP600 is the direct vessel injection of the emergency core cooling system (ECCS) flow. For all Westinghouse three- and four-loop plants with accumulators, the injection of the ECCS flow is into the reactor cold legs. Here are Babcock and Wilcox PWRs that have direct vessel injection, so this concept is not unique to the AP600 design. The AP600 has direct vessel injection in which the accumulator, core makeup, incontainment water refueling storage tank (IRWST), and the sump injection flow enters the reactor vessel. The injection of the ECCS water will result in different condensation, mixing, and entrainment and de-entrainment effects in the downcomer as compared to the cold leg injection. The primary injection during the blowdown phase it from the accumulators.
As the transient progresses into reflood, the larger AP600 accumulators extend the injection past the uA1410w.wpf:1b-092894 2-1
peak cladding temperature period until the entire core is quenched and the plant transitions into long- ,
term cooling.
Another difference in the two PIRT tables shown in Tables 2.1-1 and 2.1-3 is the presence of the CMTs as the high-pressure injection system for the AP600. This particular passive system is primarily designed to provide injection flow for the small-break LOCA and is much less important for core cooling considerations for the large-break LOCA situations since the core cooling flow comes from the accumulators.
Therefore, the most significant difference between the large-break LOCA PIRT charts for existing PWRs and the AP600 is the direct vessel injection utilized in the AP600 design. Specific WCOBRATIRAC code validation beyond that given in the _WCOBRAfrRAC Code Qualification Document is provided in this report to address that design feature.
1 l
1 i
u:\l410w.wpf:lb-092894 2-2
j 1l s
t ni p P iol p o A t s a
o $
l l
i w l 2 c o s l of g - e k l a w n n r ia ne u t
a c i s
e it o h s B
r ilrf c l s
a tn o me r p
f c D
l r m p l a
e wn u e t e u w i w lulo t
mel wo s m f I P h m r
N e n gl n
W m /i ina ar lui u o de tea g g n
s qw i
o D t t n i t t
$ re a r ei h O n tr e n -
F ,ehn 2 v tudl i s D w n -
e e 3
Con n o a ntue l a
o d C c s f W D O.
l n s g ito n
/
l g n ai o I i e, m x A I u d c s t n a i
m C
l c el di n sc I
loa P O. C oo l l
l c l
I.
l e
c s s
G n a o N
l p m I
m r o
m r
R u fr o U P e f
)
p P.
I $
2 A
1 Y
- II I
s n s o
1C 2 6 e l m
r E. AR l
R re f
o t t S P Al E l
A l h n TI c n ie n /
g n
o e wl n mis A
i R u i a n N Z P
q hger h s
a s p t
e a E ly r
t ir u l f
x M a e c s e O g n &n o t. n n
o N L e
/
n ia vi e t s e i g d
i t
E a r i
t r a n
$ ce r n d i i d 2 v I
I t
c t
n e wga oo n P I I
e de lots v v o f c D /
n N n n n) o A re m /i n a o iak pnu i
i r ei r c t a n s t d a $ ce t
a a r T pe Ul P tr n -e h a pp
( b Flla 2 v n
N e e d
e s Cf c o
E C N
O F n &n o
- s. en w t / i l
te g o n a P e r
l i
i CT t
e s ei n l i d g ir a t vi t e a N f r ne r M C o
D t I s
o I w e
r di ue l
D d i i d o o tn -
n wg a O p nt 3 v v e e lots d
C f 9
s t a
4 d e 2
o d y e g h P cu e t
5 R r r Ad c n toe y
a Gn oa R s n l
e u e c e c C -
F d G
s E
t ne a R n
n e U p
o m o
N n
m e m a h P
o r
C F eaaYh${E u
,fl :l l ,
o '
4:
e F
' ~< TABLE 2.1-1 (Cont.)
% COMPONFNr AND PHENOMENA HIERARCilY DURING LBLOCA REFILL a
T l'pper Cold Leg / Lower k
Het Leg PZR Steam Gen Pump Accum Downcomer Plenum Break Imnp !
5 Cnmponents Fuel Reds Core 11enum t
flashing /
stored entrain / steam entrain / eritical '
Phenomena: energy de-entrain expansion 29 performance de-entrain flow !
phase oxidation separation AP. form loss condensation flashing contakn-CCF (drain / ment decay heat fallback) hot wall pressure gap 2$
conductance convertion 3D 2$AP CCF, slug. '
' nonequil entrain / steam DNB de-entrain binding flow escilia6ons 9
b post-CllF flow rev & l' IIT stagnation AP fwm loss lig level use flow split rewet/ void dist. 29 top quench void gen convection satursted s nucleate 2$ nucleate boiling convection twiling
!$ vapor condensation sween
' escillations out ;
NC noncondensible 3-D flow gases het wall l void dist. multi-D i, l
void gen IIPI mixing flow l i
! entrain /
de-entrain flow rev &
l stagnation t
- From NUREG-CR-5249
- t 4
- i. - . .- ~ , . . - _ _ - . _ _ . . . , _ . . . . .- - . . .- _.._. _ . , _ , . - ~ , , , . . ...m . . . . - , ~ _ . - - - _ . - . . . . , . , , _ . . _ . _ _ . _ , _.. _ _
ll\l Il 1llf l' R
s n it P o l p
p A i
t a s l
m $
2 li w o
I c s l f
e g - e l
n k
a e
a r w o
i hs n i ae t e r u
s s
l ir tnf c
l l
f a tn o
c merp D
l l
r p a e m e i wn u e tu w w ne t
o, l wo s
t n luf m
i t P h r r, C n
- e s o gt S o d g
D m c
/ia n
i r i
t a
s ll a
D ui u qw O it 9 ce te a ci te a n O e a t n n w ls, e o l
e l n r e e I nf l v 2 v rudio O
L 4
= tn e e d
d o
n h to Un
(
o l iq e n o
c ta s n ub 1 c F
i s
e E m s
a R u c
n s on g
e g
n c i o i A A tai bl n
/s sn ta is w C e.
el d ic l n e t n
t n s d P O. o o n I l
d l c o c
I l o n I. C o c
1 G s N
I l s
o p
R m m r
U P u
f, o
)
t
.D P A
nY oll s CC
(
n e g l s
o 1
R G mn ad i
a-r r
- A m a
e n t
s i f, o
1 R e b P
2E l St A
_ E. I t
l l m a n c o A
t l R Aig n s
AN 7 P n ap TE I ih s x a e N l f
O n n n
o N s e.
/n ie t,
s e i g it E I ir a
tr tn d
d 2
$ ce I
I t
n n -e id i o o v
n e e o
_ P II d v v c D m n N m e
n tK s /n) i o
A m e
/i nar r iak t c
i P
e a
a p d ra c e v
T e tnr etn e
s
(
Tl a lb n o
N e p e e e
s Tf c
E U p d h
a L $
2 N p d
O I I T h C i o n &n o f
P I I c n g N w / i n ar il F t 1 e
te a n r o v. v i e n I e H e !n u o lf t 8 ia r ta o N w N l
w xq lei l p is f r tn n i D C e ci u bo v a D d g t n e wg ta .
O O t s
r h s fel u n S d eG lotas d ia =_
C o p
r p $
l io v
f r
9 s
y e 4 d
g n c n
2 a re c
o y a 5-ec ta i
R e ta Pt l
e d de deh e 8 c 5 u R e e r
o m
o d
n o
C -
F c ts G E
e R U
a tn n e
n o
m o
N e
n p n
- m e w C
a %
I n F
e
- abY ,3v$d' gb l I jl il ll1Ill I1 l I I llllll Ill
k l
TABLE 2.1-2 l
SUMMARY
OF EXPERT RANKINGS AND AHP-CALCULATED RESULTS* I Blowdown Refill Reflood Base Base Base Expert .Line Expert Line Expert Line Rank (AHP) Rank (AHP) Rank (AHP)
Fuel rod stored energy 9" 9 2 2 ,
oxidation -
1 8 7 l
~
decay beat 2 1 8 8 gas conductance 3 1 8 6 Core i' DNB 6 2 2 post-CHF 7 5 8 8 4 ,
rewet 8 8 7 6 1 ,
reflood beat transfer - - 9 9 ;
nucleate boiling 4 2 2 :
1-phase vapor - 6 4 L natural circulation 3-D Flow 1 3 9 7 void generation / distribution 4 6 9 7 entramment/de-entrainment 2 3 6 flow reversal / stagnation 3 1 1 radiation beat transfer 3 I
Break critical flow 9 9 7 7- 1 3 2 1 2 4 2 Loop
- 2-phase Ap 7 7 7 6 oscillations -
7 7 9 9 flow split 7 7 7 2
- From NUREG-CR-5249
- 10 is the highest, most important; 1 is the lowest u:\1410w.wpf:lt4)92894 2-6
l]
' i > ;1?l1I o
n a n n )n f oi u ni to o l
t f tc s i c o c oce t Ode I n
ri it c
e r
ej i
n lai
(
mj n
p wi t a $ p e 2 A olp lf s L
l g - e k n mt urs ihs a n a a w c
e r uo l a
t e n mesr B nf o c lf c g re mu p l
D N e t e u a
w -w lu o W el ne wo s
t o uf ml O l P h D r .w n tole gl o n ss W e m /i n
n uf i o de te g a n g
n oi e v i a i
o D t
c ta leii i
O. c a tr r n ls.iuql $ev r l hs Wni o r n -
2 o I
I I w o
n -e t
e e 3
7e 1n n
o u
t cu vx a nl s
l f
a lacet ja t
c d ( o c n e A D n i r C l e n s we r
O s s n oo u n g l omo L e o ai s t n f na c
t Vi tc nl a ix i
L t e deli i
ew cd e r n cs m do g d rI o GN L H c o nio f
NG I
I e s
RS c n I m
2 r o o 3 Y0 I f r f.
I 0 -
p P I 6 A 1 C l' 2 RA m n P . ms EA R Sae teG A foo r s l
LRE O l
l Al Fi h
c n ie n I f D n e wl i n
/
g n mis o
AE R u I Z q io e g h i a n s e a NF P ly t
t r u l a s px t
EI r ms f e
MD a
e
_ O N M O
g e
/
n ia n & n vi o t .n is e i n
o t
d g ia tr e r ta $evc
_ E I
I P
I H
t a
r e e d n
n < wga t
lots f
n d i i d oo v v 2
n o
c D m n
o n N u n i
t a
f n o A
i n
e tn a i r i) ak t
c i r a r c e p
T l
P d a v a
r tn e ( b n N r e
t n - e s e Tlla o c
E p e e d s a If $
(
N ip l
hp 2 O
I' ;
t.n n , n l
e g w i o M e l t e
t a n o dsig e 'tna r vi liCT i
i l a t e, at r w lei r n f
O o N I d n u bo D io c li d i n -e wga t
D t I s e C C r o o v v e de ns p n 3 ot j
y e s g c d r ta n e e e a n h pt R e y a c d a g u d e c d n
u r e o
F t o d c s
s t -a n
e n
e n m a
p o n
n e n
e h l'
C
= $ . ?;3 1; kf
- ,l l 11' I1 TIE
l!lI 1 n n -
Tl te iooumro t
Mce ot n e c e ut Cdr jd ual a n
I i s i
p a s o $ p l
l i n wi t o 2 A c o s i lolp s L o t f l g - e r
k a n mt an e u a c w i s
e i i h t B
r ikt r i c l f
s a n mesp o
c r
rm eu p
e t l
l a D
-w
, woen e u wo w lu o L Ll P s t
o ul m
f L
I h
F r n ,w e n E e n o gl o s e o de te m / i n ar ua l l
a lof i g R c o i a t s n w D , lm s l
e 9 ce t
ta a n lei n r n e
- v 2 v r l A -e t t 3 Tq e e u c i o w n d o l n t a ub e e C D o d n
o h t C onn iq o c
s n c l O.
l l e n s te-l s n o i
L s e en uai no n e e s
g s n Vi t s t d a i G c n a n g x t e cg ell o i c e N e r di e n nb l m R N I irI D
om c
o n
U G s
)
I ec s
1 S n o Y) E l
)
p a t I I m 0m m r
nI u 2 r o o 0 P f f.p oC) r C( RM p e
A A P g 3-RA m n ae mn P ,ms ad i
r s 1
2I ER teG S
t e n s i Aof lo I O h E, I F i A n l
l N D /g n mis o
R AE E I Z i a n hsa te a TMF l P l f
s p x
e Ol l NO n &n o n EM I
I g
e
/
n i a r vi s. en t
i d g i
t o
L a i
t e t r a $ ce I' r n n 2
)
e c tn - e wg di id oov v
n I
I I
e e d ot a s v o N l f c A m n
o n T u n ua /
n) o n /
iak i
t N l e n i a r
r a
p r c c e
E P iat r n e d a
( b v
n N r e tn -e e e s
e Fl a l
o c
O p d s Cf P p a C 9 U h p
2 M h O F c r n &n w s. en n a vi to t
I
/t n te g o o
/i C e B e e a n p di g r
o N ICTI w uq lei aC l f i tr r a
r ne e a n
o vN
- l C D t s
o I
e t p uci D do i id tn -
o e e wga p o n b 19 3 v v d ot s
t lf y
s g e n
t a c d
o r
e e n n w h a R e t a y pt a c l d d a g u ae e n c d i r o e n F o d o t
s c t
s :
a n n e e n m e o p n m e a h l'
C eaeo$ 378Mf f*
t
1(jl i Jljj1lfjl l n n -
o 1 i 1 tc
- iooum<w t
" jc t
0je e ueut cl a In in d ca p s s m lwh l t o $P l ici op o 2A s t f s l o -
t w n lo g e e k
a f n mur e
r la i
hs mss i
l ic t l a ta n t e
f s ir o c c t
u rm o ua D D eu p w iw-wne e t
o O e t o luf l el w h m O l P s L
F r ,w C n ol e n gol o s E e n o S i d e tn O a ng Mis l
i uf tc tev e R m e
/i mr a t s
a l
a D ls, ul i l e
e v a ei d mv c e r tn n w -
v n rl l t P kt r A n ta e e t n
3 Oe q e i cd o n u w Act o jea c d c s a nt C
)
w o c e d n o
h Cn o l
iq $ iner A D c n l 2 r
I e e B, t n s l b w r
io n o mo s
e n i
e s l g
I o tain s s n fm n r
G Vt i c
s t nl el a iesa i ix kwo NN I
tc e eQt di c ms .m g m t
cd e
yo RG I M rI c o m nt n US i
I
)
. DE D s s
t nY I )
oI M p l o
n m n CCM
( u o RP P f, P
3 AA A 1RR 2E El F l O m mm g n n
ass L I am ad e n f, o BA D S teG tsib P l A
AN E I TEF hc m me ae no MID R n
e u wI m tsis OO Z q o e /g n N M P l
ly t ru n f g a p
E tu x l
r a e e
ns s e a
i l t
P n t in t.n o D 4 n a r dsi g e i N 1 iat r n e d d 2 v
$etc A t n tn -
e e v v io o
i n
I d o I c T
N n n w o u) m E rm eu /a n r e i
s i t ak r c h
t r n a ra $ e i
N pn pe a t d t
a b 2 wn O tn -e ha p l P
I UlP e de g e s Gf C
l a o c
% I I T h C n &no I
l O I T cn te g N w t.ns /i na I
' t I e r o di eg vi n C e r
B N
I I e w
d u a n lei l o
p l
f ir at r n e ta r n m D diodoi tn I
o C e imqs ci o a -e wga t
C D - r u uh n v - ee ot d ai ts f el $
3 v v d f s l
a o r p I r p
a t s d y m y l
ed e g r r ta a ta pu ct e oe ad g nan toR di dec tr I
s en t
x c o
o s :
a tn n e e n n o n p a v
n e e
t h
T C
~.
aae?fy3b y6
t 2.2 Comparisons of the Large-Break LOCA Transient for Current PWRs and AP600 The current PWR large-break LOCA transient that was selected to be compared to the AP600 transient was Nonh Anna (VRA), which is a three-loop,17x17 fueled plant. The basis for the choice was that the fuel design is similar to the AP600 fuel type, and the AP600 has a three-loop sized reactor vessel.
The details of the North Anna transient and the sensitivity studies performed on this plant are given in theIVCOBRA/ TRAC Code Qualification Document, Section 22.*
2.2.1 VRA Transient Description The large-break LOCA transient can be divided into time periods in which specific phenomena occur.
A convenient way to divide the transient is by the various heatup and cooldown transients that the hot assembly undergoes. For each of these phases, specific phenomena and heat transfer regimes are important, as discussed below; Critical lieat Flux (CHF) Phase In this phase, the break discharge rate is subcooled and high, the core flow reverses, the fuel rods go through departure from nucleate boiling (DNB), and the cladding rapidly heats up while core power shuts down. The hot water in the core and upper plenum flashes during this period. This phase is terminated when the water in the lower plenum and downcomer begin to flash. The mixture swells and the pumps, still rotating in single-phase liquid, push this two-phase mixture into the core.
. Upward Core Flow Phase lleat transfer is improved as the two-phase mixture is pushed into the core. This phase may be enhanced if the pumps are not degraded, and the break discharge rate is low because the fluid is saturated at the break. This phase ends as lower plenum mass is depleted, the loops become two-phase, and the pump head degrades. If pumps are highly degraded or the break flow is large, the cooling effect due to upward flow may not be significant.
. Downward Core Flow Phase The loop flow pushed into the vessel by the pumps and the level swell caused by the flashing mixture in the vessel is more than offset by the break flow. The break flow begins to dominate and pulls flow down through the core. For some plants, this period is enhanced by flow from the upper head. As the system pressure continues to fall, the break flow and consequently, the core flow, are reduced. The core begins to heat up as the system reaches containment pressure and the vessel begins to fill with emergency core cooling system (ECCS) water.
u:M 410w.wpf.15092894 2-10
. Refill Phase The core continues to heat up as the lower plenum fills with ECCS water. This phase ends when the ECCS water enters the core and entrainment begins, resulting in improved heat transfer.
. Early Reflood Phase The accumulators begin to empty and nitrogen enters the system. Reflood oscillations occur in the core liquid level.
- Late Reflood Phase The accumulators have emptied, and the core is filled via pumped injection. A second heatup and cooldown period may occur.
2.2.2 VRA Base Case Results (
'Ihe VRA base case is chosen because of its conservative plant operating conditions, which will lead to l l
a higher peak cladding temperature. In this regard, the base case is similar to a superbounded ;
calculation in which the uncertainties in the plant operating condition are bounded. I l
The VRA reactor vessel is shown in Figure 2.2-1. The WCOBRAffRAC model of the North Anna plant is shown in Figures 2.2-2, 2.2-3, and '2.2-4. The reactor vessel model noding detail is given in Figure 2.2-2 [
I
]" The important initial and boundary conditions assumed for the base calculation are summarized in Table 2.2-4.
After a 20-second steady-state calculation, which is a transient calculation with fixed boundary conditions, the LOCA transient was initiated by applying the containment pressure to two open ends of the broken cold leg in loop 2. The system pressure is shown in Figure 2.2-5. The maximum cladding temperature (or peak cladding temperature) of the hot rod in the hot assembly is shown in Figure 2.2-6. Figure 2.2-7 shows Te,o at various elevations. Figure 2.2-8 shows the axial profile of the hot rod cladding temperature at several points during the transient.
uA1410w.wpf:lh092804 2-11
. Blowdown Period At the Break The blowdown period lasts for about 30 seconds until the vessel drops to the containment pressure. 'Ihe mass flowrate in the vessel side and loop side of the broken pipe quickly increases to -55,000 lbm/sec and ~25,000 lbm/sec, respectively. The fluid velocity at the break is limited by the local sonic velocity at this point. 'Ihis choked flow condition exists for approximately 20 seconds. Due to a large pressure drop through the steam generator, there is a significant difference in the pressure and the void fraction between the vessel and loop side of the broken pipe during this period.
Core Fluid Condition The liquid flowrates in the average channel adjacent to the hot assembly and in the hot assembly at the top and bottom elevations indicate that in the base case the hot rod receives little cooling due to upward liquid flow. A significant downward liquid flow occurs, resulting in improved cooling as the flow reverses due to the break. The core flow at the top and bottom of the hot assembly is shown in Figure 2.2-9. The average channel core flow is shown in Figure 2.2-10. This is consistent with the blowdown cooling pattern for a large-break flow and/or a degraded pump, as described in the previous bulleted paragraphs: CHF phase, upward core flow phase, and downward core flow phase.
- Refill Period The refill period is characterized by a rapid increase in the lower plenum collapsed liquid level and the vessel fluid mass. In this period, the cladding temperatures at all elevations increase rapidly due to the lack of liquid and steam flow in the core region. This results in poor cooling, as seen in in Figure 2.2-7 and curves 2 and 3 in Figure 2.2-8 (t=40 to 70 seconds).
- Reflood Period The early part of this period is characterized by a rigorous vapor generation when the lower section of the core receives liquid from the lower plenum and subsequent core /downcomer oscillations with steadily improving core heat transfer. At around 120 seconds, ECCS water accumulated in the lower plenum starts to boil. The vessel fluid mass also shows a long-term oscillation, caused by periodic injection of N as 2 the vessel pressure decreases, which results in a ;
reduction in steam condensation in the cold leg. This causes injection of colder water into the j downcomer where Miling is taking place. 'Ihe downcomer level is shown in Figure 2.2-11, and I the core level during reflood is shown in Figure 2.2-12. In the late reflood phase, the cladding at the top of the core continues to heat up while the quench front advances from the bottom-up cooling curves 4 and 5 (as shown in Figure 2.2-8).
l 1
u u:unour b-092894 2-12
2.2.3 AP600 Large-Ilreak LOCA Transient The AP600 WCOBRA/ TRAC model has been developed in a consistent fashion with other PWR models.* Be AP600-specific features, such as the reactor vessel reflector stmetural design, operating conditions, and loop configuration can be treated through the code input. The AP600 reactor vessel is shown in Figure 2.2-13. The reactor vessel nodalization is shown in Figure 2.2-14 and is similar in detail to the VRA vessel shown in Figure 2.2-2.
[
4.C Figure 2.2-15 shows the cross section of the reactor vessel at the core elevation. [
]" This modeling approach is consistent with those used in two , three , and four-loop plants, as discussed in the WCOBRAfrRAC CQD, where [
ju The loop model for the AP600, which is similar to the VRA loop, is shown in Figure 2.2-16.
The initial plant conditions for the 3' COBRA / TRAC large-break LOCA analysis are summarized in Table 2.2-2 for the AP600 superbounded analysis. He 10 CFR 50.46 stipulates that the PCT be calculated at the 95 percent probability level. Such a calculation includes consideration of the components of analysis uncertainty, including: the computer code, accident initial conditions, accident boundary conditions, and the uncertainty in plant parameters / systems.
In a superbounded analysis, bounding assumptions are made concerning a number of the initial /
boundary conditions / parameters, as detailed in Table 2.2-2. Referring to that table, item by item:
- Bounding high-power and steam generator tube plugging (SGTP) values are chosen together with minimum system flow. f
. Plant design is such that no active failure of a safety-related component significantly impacts large-break LOCA performance. Minimizing the accumulator delivery bounds the uncertainty l in system performance pertinent to the large-break LOCA event. l
- A worst-break case is identified within appropriate break modeling uncertainties.
- Ilot rod fuel pellet temperature is conservatively maximized.
uM 4 toug n,-oo2894 2-13
. A conservative axial power shape is used, based on previous WCOBRAfrRAC studies.* ,
- A minimum containment pressure is conservative.*
- Bounding values for peaking factors are used to provide the highest linear power and enthalpy rise heat rates.
. The AP600 contains many guide tubes that provide drain paths for upper head fluid into the core during a LOCA event and also upper support plate holes to facilitate such draining. The hot assembly location in WCOBRAfrRAC is specifically chosen so that no such direct flow communication exists for draining upper head fluid into the hot assembly. This will penalize the hot assembly during the downflow period of blowdown.
= A best-estimate decay heat approach is applied with uncertainty (2 sgma) placed on the hot rod to bound its decay power.
- Both the accumulator initial condition and the uncertainty in the gas expansion constant are set to minimize accumulator delivery. The accumulator temperature was set to the maximum containment temperature. The accumulators provide the only ECCS injection that influences the resulting PCT. Operating bands and plant uncertainty for the accumulator are accounted for in a minimum delivery case that considers maximum initial water volume, minimum gas pressure, and maximum frictional resistance. Furthermore, the gas expansion coefficient is held at a high value throughout the AP600 large-break LOCA transient, even though the extended length of the accumulator delivery indicates that a lower value is appropriate. The net effect of these assumptions is to conservatively model the accumulator injection rate for refilling the reactor vessel and core.
A spectrum of large-break LOCAs at different break locations and discharge coefficient (Co) values were performed for the AP600.* A description of the most limiting break, Co = 0.8 DECLG, follows.
The break was modeled to occur in one of the cold legs in the loop containing the core makeup tanks (CMTs). Past sensitivity studies with WCOBRAfrRAC* have demonstrated that locating the cold leg break in the loop that does not contain the pressurizer renders conservative results. The steam generators are assumed to be isolated immediately upon the inception of the break in order to maximize their stored energy. Shortly after the break opens, the vessel rapidly depressurizes, as shown in Figure 2.2-17, and the core flow quickly reverses, as shown in Figure 2.2-18. During the flow reversal, the hot assembly fuel rods dry out and begin to heat up. The massive size of the brm-causes an immediate, rapid pressurizadon of the containment. One second into the transient, credi. u taken for receipt of an "S" signal due to high containment pressure. Applying the pertinent signsi processing delay means that the valves isolating the CMT from the cold legs and direct vessel injection line begin to open at 2.2 seconds into the transient. Automatic reactor coolant pump (RCP) trip occurs 17.2 seconds into the LOCA transient, until which time the RCPs are presumed to operate uA1410ws%1b-092894 2-14
)
i i
l l
normally. Core shutdown occurs due to voiding. No credit is taken for the control rod reactivity effect.
He system depressurizes rapidly as the initial mass inventory is depleted due to break flow. He pressurizer drains completely 7 seconds into the transient, and accumulator injection begins 12.5 seconds into the transient, as shown in Figure 2.2-19. Accumulator actuation shuts off CMT flow. '
- the isolation valve opened. De CMT liquid level remains well above the ADS sta, . tion setpoint during the blowdown phase of the Co = 0.8 DECLG LOCA transient.
De CMT flow is illustrated in Figure 2.2-20 and shows that the CMTs initially provide flow to the reactor vessel very early on in the transient. As the pressure drops, the accumulators begin to discharge and create a sufficient backpressure to close the check valves at the CMT discharge lines.
The CMT injection r dmost as quickly as it begins, and only 0.5 percent of the total CMT inventory is injectet when this injection occurs, the core flow is downward and the downcomer is in a bypass mode so unat the CMT injection flow is bypassed through the break. The CMT, therefore, does not contribute to the core cooling during the large-break LOCA.
he dynamics of the Co = 0.8 DECLG case are shown in terms of the flow rates of liquid, vapor, and en: rained liquid at the top of the core for the low-power periphery, open hole / support column average power interior, guide tube average power interior, and hot fuel assemblies. The clad temperature transients are sho - the 6-ft., 8.5-ft. and 10-ft. elevations in Figures 2.2-21 to 2.2-23. In these figures, rod 1 refer. _ the hot rod at the maximum allowed linear heat rate; rod 2 represents the I
average rod in the hot assembly that contains the hot rod; rod 3, the open hole / support column rod; rod 4, the guide tube rod; and rod 5, the low-power peripheral fuel assembly rod.
Figures 2.2-24 and 2.2-25 illustrate the impact of upper head drain through the guide tubes and upper support plate holes, respectively, on core flow While liquid remains in the upper head above the top of the guide tubes, the guide tubes (Figure 2.2-24) are the preferred path for draining liquid into the upper plenum. Top-of-core flow is relatively stagnant for the first few seconds; once the upper head begins to flash, liquid drains directly down the guide tubes, and is able to penetrate into the core against continuous steam upflow. Liquid flow rates that exceed 600 lb/sec of continuous liquid and l 100 lb/sec of entrained droplets occur between 4 and 13 seconds. At that point, the flow entering the guide tubes in the upper head is almost entirely steam; residual liquid is supplied to the guide tube fuel assemblics at an ever decreasing rate up to 20 seconds. De larger flow area between the upper head and upper plenum for the AP600 results in a larger and more substantial downflow in the core as compared to VRA.
Figure 2.2-25 presents the open hole / support column assembly top-of-core flow behavior. In contrast to the guide tubes, flow of liquid down into the core open hole / support column locations does not become significant until about 8 seconds of the Co = 0.8 DECLG transient. Between 11 and 18 seconds, the combined flow of continuous and entrained liquid is 600 to 700 lb/sec; the entrained liquid flow continues to be significant until 23 seconds. After 10 seconds of transient, the downflow u:\l410w.wpf:1b-092894 2-15 l
pattern in the open hole /suppon column locations is established to the extent that vapor downflow is also predicted. During this time interval, vapor flows up out of the core in the guide tube locations.
Thus, there is a good flow of liquid into the top of the core at these locations from before 10 seconds to almost 20 seconds. The flow in the open hole and guide tube assemblies is sufficient to quench the fuel in the assembly (rod 3 and rod 4, respectively) at the 6-ft.,8.5-ft., and 10-ft. elevations, as shown in Figures 2.2-21 to 2.2-23.
Because the hot assembly can only receive draining liquid from the upper head indirectly, liquid downflow is delayed into this assembly. Nevertheless, by 10 seconds into the transient, liquid that has built up in the global region above the upper core plate begins to flow through the plate at the hot assembly location and then proceeds into the core (Figure 2.2-18). There is a significant flow of continuous and/or entrained droplet liquid into the hot assembly from 9 to 18 seconds. The liquid flow is enough to quench the hot rod and hot assembly rod at the 10-ft. elevation (Figure 2.2-23), but not at the 6-ft and 8-ft. locations (Figures 2.2-21 and 2.2-22), although there is effective cooling at those locations. More recent WCOBRAfrRAC versions that are consistent with the CQD may predict >
quenching of the heat assembly rods, whereas the 1992 version reported in the SSAR has not.
Figure 2.2-26 demonstrates that liquid downflow exists through the top of the peripheral core assemblies from the first fraction of a second through the end of blowdown in the Co = 0.8 DECLG transient. The low power of the fuel in this region leads to a small clad temperature excursion for the peripheral rod, shown in Figures 2.2-21 and 2.2-23. Some of the initial upper plenum inventory passes through initially, cooling the fuel. Thereafter, liquid downflow travels from the upper head into the core through open hole / support column and/or guide tube channels and into the global region ,
above the upper core plate, and is then delivered into the low-power peripheral channel.
By 11 seconds into the transient, the entire length of the peripheral rods are quenched and remain quenched through the end of blowdown.
As the vessel depressurizes during blowdown, liquid inventory continues to be depleted and the hot ,
assembly void fraction increases (Figure 2.2-27). Curve 1 of Figure 2.2-27 is at the bottom of the I active fuel, curve 2 is the void fraction at the core rnidplane, and curve 3 is at the top of the core. !
I
'lhis results in reduced core flow and the cladding temperature excursion for the hot assembly. Later, clad temperature excursions occur at other regions of the core.
About 12.5 seconds into the transient, the accumulator begins to inject water ictn the upper downcomer region (Figure 2.2-19), initially, bypassing some of the water to the break. At approximately 21 seconds, accumulator water begins to flow into the lower plenum. Lower plenum and downcomer liquid levels are plotted in Figures 2.2-28 and 2.2-29, and the core hot assembly liquid level is shown in Figure 2.2-30.
u:\14IOw.wpf:Ib-092894 2-16
l l
At approximately 56 seconds, the lower plenum fills to the point where water begins to reflood the core from below. He void fraction at the core bottom begins to decrease (Figure 2.2-27). Eventually, !
core cooling increases substantially and the peak cladding temperature (PCT) begins to decrease as the .
core water level rises.
Figures 2.2-31 through 2.2-33 present plots of PCT at the 6,8.5- and 10-ft. elevations for the first 2 minutes of the blowdown and reflood phases of the entire transient and shows the hot rod PCT up until the start of the long-term cooling phase. Rese figures illustrate the clad heatup response (and PCT turnaround) for both the blowdown and reflood phases of the limiting Co = 0.8 DECLG break) as being 1565'F at 102 seconds.
It should be noted that more recent AP600 Co = 1.0 large-break calculations have shown hot rod quench during blowdown with WCOBRA/ TRAC-Mod 7A version of the code. There calculations were supplied in response to RAI 952.46.
The gradual heat up of the fuel rod after blowdown and dudng refill and reflood is due to the lower accumulator flow for the AP600. The lower accumulator flow is specifically designed to extend the injection flow for a longer period of time and to provide additional injection coverage for small- break LOCAc The AP600 accumulators are also substantially larger than the VRA accumulators, with 1700 ft.S water volume per accumulator, as compared with VRA accumulators, which have 1050 ft.' Also, both AP600 accumulatcis are available due to direct vessel injection, whereas in the VRA analysis, only two of three accumulators are available because the broken loop accumulator spills to containment.
The AP600 accumulators are the dominant injection system for a large-break LOCA because of their increased size and the extended duration of water flow.
The phenomena observed in the AP600 SSAR calculation is very similar to that seen in the VRA calculation. 'Ihis confirms that the PIRT charts for both AP600 and existing plants should be basically the same and that ,WCOBRA/ TRAC can represent the AP600.
i i
l t
i a:u4 ton #1MNn94 2-17
TABLE 2.2-1 NORTH ANNA (VRA) INITIAL AND BOUNDARY CONDITIONS Parameters Value Plant Physical Description Pressurizer Location intact loop Hot Assembly IAcation under flow mixer Hot Assembly Type 17 x 17 V5H w/o IFM Steam Generator Tube Plugging (SGTP) 15 %
Plant Initial Operating Condition Core Power 2898 MWt (5.955 kw/ft.) ,
Hot Rod Average Power 10.12 kw/ft. (FAH=1.7)
Hot Rod Peak Power 13.54 kw/ft. (FQ=2.5/1.1)
Iow Power Region Relative Power 0.8 Axial Power Distribution 7.8 ft. peak (AO=12%)
Hot Assembly Burnup BOL (500 MWD)
Plant Initial Fluid Conditions T,,, 586.8"F Pressurizer Pressure 2250 psia Loop Flow 92,800 gpm/ loop (minimum rninus uncertainty)
T t*H T,c, Accumulator Temperature 100 F Accumulator Pressure 618 psia j Accident Boundary Conditions Break location cold leg Break Type guillotine Break Size 1.0 x pipe area Offsite Power on Safety injection Flow minimum minus uncertainty Safety injection Temperature nominal (45 F)
Containment Pressure lower bound uil410w *T :ll>O92894 I 2-18
I l
1 TABLE 2.2-2 AP600 CONDITIONS FOR TIIE LARGE-BREAK LOCA SUPERBOUNDED CASE
- 1. 102% core power,10% uniform steam generator tube plugging, and minimum flow of reactor coolant are assumed.
- 2. Only safety-related systems operate.
- 3. Beginning of life cycle 1 conditions are analyzed to maximize core stored energy. Fuel average temperature uncenainty applied to hot rod only.
- 4. Top skewed power shape with a positiv- 25% axial offset. ,
- 5. Lower bound containment pressure.
- 6. Conservative maximum values of peaking factors, (F, = 2.6, Fa = 1.65).
- 7. Ilot assembly is placed in an isolated location to minimize blowdown cooling.
- 8. 1979 ANS 5.1 decay heat with uncertainty on hot rod only.
- 9. Accumulator flow delivery minimized to extend bottom of core recovery time.
- 10. Accumulator temperature set to maximum containment temperature.
I1. Single failure postulated is the failure of one of the two parallel path, intact loop CMT isolation valves to open upon receipt of signal.
u:\l410w.mpf;1MJ92894 2-19
a,c b
l l
- Figure 2.2-1 Nortin Anna (VRA) Vessel Drawing l
u A14W-1.spf:1t> 092894 2-20
l l
l 1
I l
a,c 1
V i
i F
h i
Figure 2.2-2 VRA ECOIIRA/ TRAC Vessel Model Noding u:\l410w.13pf;1W2894 2-21
l a,c t
l i
l 1
l 1
l Figure 2.2-3 VRA Vessel Cross Section Noding u:\1410w-1.wpf:1M92894 2-22 i
l
a,c l
l l
l 1
l 1
1 i
I 1
Figure 2.2-4 VRA Loop Noding u:\l410w 1.wpf Igog;gg4 2-23
a,c L
j Figure 2.2-5 VRA System Pressure 1
ud1410w-1.wpf.lb-092994 2 24
l l
[
t t
VRA Scoping Study Cose SCO28 (Base Cose) l PCT vs. TIME ,
i ! I I I I i : First Reflood ;
i : Ped AY%vh i ,
i
- m
/
V m~
/
- 7 I
T W ,
1600 q
- g I
\ i
/0., Second Reflood C
- i. ;
Peak w i D
/:l*
e- . . ,
.c : :
m : : i w : '
i a, -
W . ?
1100 . .
lj Refill Period ,
e-HW ! I h i ,
Blowdown i Period l 600 100 0 200 300 l TIME (S) I i
i Figure 2.2-6 VRA Peak Cladding Temperature uA1410w1.wgtho)2894 2-25
VRA Best Estimate LOCA Scoping Stucy Base Case TCLAD NO. 1 Axiol ~ Tempercture Profile at Various ronsient Time t=26.S see, (Blowcown Peck T*me)
---t-35.5 sec. (After Blondown Cooling)
G -- E t = 50. 5 sec. (Ref;II Time)
@ - 6 t = 110. see. ('st Reflood Peak Time) d - - A t =220. sec. (2nd Refiood Peak Time) 2000
,. A
.s' s' ,
T
/"%\;.f ,
9\ k 1500- jg/ ; ,
1
' Ds- .i(D. N. a l m ~
g N
- u.
- j s ' / ,/N'3 's i, n.'- g.
s.
s-g I
\
- i i O -.
e l
E t,N 8
/ . s, Q.g , %, \- .
S 10CD- //
gl la-
/
. 1s
,' g s-i e i, i p / 1 l
A % 8
\'
8 s 8 I g'.
w
~
I j
.' In I
8 I .
1%
l.
o I I
- 1
' \' L 500-'I' si l ,= y-L l s. I
-e-6-bA-A-A s.b 0
- 0. 2.5 5. 7.5 10.
ELEVATION (FT) l l
Figure 2.2-7 VRA Cladding Temperature at Different Elevations uA1410w.1.wpf:lt> 092894 2-26
VRA Scoping Study Case SCO2B (Base Case)
Cladaing T e m o e r o t t. r e vs. IME TCLAD 1 40 1 ELEv. 5.92 FT.
O---'*]TrD 1 54 1 ELEV. 8.05 FT.
O- Orc.-D i se 1 EtEv. s.33 rT.
A -ATcL AD 1 69 1 ELEv. 10.33 FT.
l l l a.
,)W' *% 'g'I N ' * -
1700 #
. .O '
r u. m A Att~~ ~.(t
. E<lt. ,,jg .b
{f fh p , ~'h Q
\
[ / Q* 'Q g' %,G',_
^
t Pk/
' i ,/.'I . I
/ fek , *m,
" , ;' ** J '. .,
i s. .
1200 i ','O y
kD
$ ! I'(I
. ,f n
3 ,
5 !. .' M i.
w i a
m 1
i
,P 4 d I i <
/ l I I F
700 1
/ I j
f'i l u
l l
I / !j . I i / I l t! [
l
' U' . 21:- - - -: ,:=
l 200 200 300 0 1C0 TIME (S)
Figure 2.2-8 VRA Ilot Rod Cladding Temperature at Several Points during the Transient u:\1410w-1.wpf:lh092894 2-27
1 i
i VRA Best Estimate LOCA Scop'ng Study Bose Case Continuous iquic Ftcw ct Top ord Bottom of Hot Assembly Top
- -- - Bo t t om '
5 , .
1
'l 1
l l
l 1
1 0 . l , _3_ ___
, ,s ,.__________ ,
,i l
'g
- %. 1 3
^ g I 3 m 3 :I g 8
I
- N i'
i g ,
2 I i I C
1 I g 1 -il 3 J 3 v i g
I /. 1 l I 8 l i
I ig/.i 1 i .s 3
3 y 1 g i l ,/ g
+ 1, .Y l/ 3
< 's J
p \s is 'l 'lg, g* i o ,1 8, 8 ,8 8 m
li, f M ,il 2 ,t
's
-10 8
'l I
'll I
'll
'l
'l 1 1 1 l
'3'
-15 I 20 25 30 35 40 T!ME (S)
Figure 2.2-9 Continuous Liquid Flowrate at Top and Bottom of Hot Channel during Blowdown uAt410w-1.mpf;lb-092894 2-28
i b
i VRA Bes: Estimete L O C'A Scoping Study Bose Ocse Continuous Liquid Flow at Top and Bottom o. ,
Average Cnorne' Adjacert to Hot Assembly :
f TCP $
Oc t t om 500 ,
?
I
'l .
I I I j l
I i
I .
0- I
,- --- s ,.---------
r I \ i n
tn I
f
\
.%. .', ~ i N I 1 a s
Q I l
a v 8 i
I I
i w 8 :
- I x
< -500- 8
, I w a o , I l
u'. I w I '
w
- g
< l 2 I i I
i l .i
-1000 t qi i e'I
'l i I
i i '
, I I
I I
g l-I 1
-1500 s
20 25 30 35 40 TIME (S) ;
i Figure 2.2-10 Continuous Liquid Flowrate at Top and Hottom of Average Channel Adjacent to Hot Channel during Blowdown n:u 4 tow-1.wpf:15092894 2-29 1
i VRA Best Estimate LOCA Scoping Study Base Case Downcomer Collapsed Liquid Level 30 C
u.
" 20- I t
d I '
d
} d 5 i \
? \
l l ,
B
$ 10-8 o
Core /Downcomer Oscillation ;
i
\ i 0 : :
0 100 200 300 TlWE (S) q J
I I
Figure 2.2-11 Collapsed Liquid Level in Downcomer um4to -13pr:1t> a :894 2-30 ;
I
Best Estimate LOCA Scoping Study Base Case Core Channel Collapsed Liquid Level LQ-LEVEL 2 0 2 COLLAPSED LIC. LEVEL 12 m -
H U
b -
W
> 8-W -
-8 .
O -
~
-)
6-o a
W g -
I, l O
_a
~
$ N
-8 2-
- M o
O j Y g
-f,,
o 50 100 150 200 250 300 350 l TIME (S) l I
Figure 2.212 Collapsed Liquid Leselin Core u M 410w-1.wpf:It>-002894 2-31
-- i a,c l
l l
i l
l l
)
i Figure 2.2-13 AP600 Vessel Schematic a:\1410w-1.wpf:1tw)2894 2-32
f 2,C l
l I
l 1
l f
I l
\
l I
i Figure 2.2-14 AP600 WCOBRA/ TRAC Vessel Noding u A1410w-1.wpf;1h092894 2-33
1 l
a,c l
)
1 i
i i
Figure 2.2-15 AP600 Section 4 Noding u:\l410w-13pf;1b-(92894 2-34
1 i
i a,c .
1 I
l 1
Figure 2.2-16 AP600 Loop Noding ust4 tow-2.wpf-tw2894 2-35
l 1
I 1
l Ap500 LAAGE BREAK LOCA CASE 1 2500.
2250. -
2000. -
C
- 1750. -
U3 CL
~
1500. -
LJ W
@ 1250.
O LJ
{ 1000. -
750.
500.
250. -
D. 40.
-20. -10. O. 10. 20. 30.
TtuE (SECONDS) 1 ,
i l
l ,
l Figure 2.2-17 WCOllRA/ TRAC AP600 Primary Pressure for the Co=0.8 DECLG Break l
l l
[
uS1410w.2.wpf:1bo92894 2-36 5
I l
l l
l l
l l
l Ap600 LARGE BAEAK LOCA CASE 1 O EO
\
LI m
N g 15-
)
z 10-L
- 5-0 1 ,_ -
z - _
i W .
Y l
5 5 -
c
~
5 3 1s--
-20
-20 10 0 10 20 30 40 TIME (SECONCS) 5 Figure 2.2-18 Cp=0.8 DECLG Illowdown, Top of Core Flow,Ilot Assembly Channel l
u:\l410w-2.mpf;1b-092894 2-37
Ap500 LAAGE B A E Au:: LOCA CASE 1 B00 700--
U 500--
y t
h 500--
m 400--
3 300--
e h 200-"
10C--
J e :
=100 B0 100 120 2D 0 20 40 80 TIME (SECONOS) 2 Figure 2.2-19 Cp=0.8 DECLG Transient, Accumulator Flow Rate From One Tank u:\l410w 2.wpf:1bo92894 2-38
f
?
V xa fs y a CMT Drain Flow E w t, ,
[ 160 eur., \
~
S 140 <
wet ,
n "
i 120 - ...'.'..
_g i
y u y y -
e 2 100 ~
4 'g : .. '
y @, 80 '. c .' '.
w g n
~
' 2 60 '.
P
' 3 .
o 40 :
P E _
5 '
I & 20-e m - .
n ^l O y ..
p '
O y .... ....
y . . . . .. . . .... ....
40 5 10 15 20 25 30 35
!. 0 Time (s) .
l l
l I
1 Ap500 LAAGE BREAK LOCA CASE 1 1400.
1 I
1200. -
W W
tw g 8
C 1000. f W
900. -
C CW W
6 600.
400.
200.
- 20. -10. O. 10. 20, 30. 40.
TIME (SECON05) 7 Figure 2.2 21 C3=0.8 DECLG lilowdown, PCT at 6.0 Ft. Elevation, Rods 1 thru 5
= A14 tow-23giso92894 2-40
~. - -
1 l
l 1
1 AA500 LAAGE BREAK LOCA CASE 1 1600.
1400 -
6 d
oc 1200.
S /#
o 1000.
E E 800. -
m Y
5 H
z di 600. i 400. -
200. D. 10. 20. 30. 40.
-20. -10.
TIME (SECONOS) 6 Figure 2.2-22 Co=0.8 DECLG Illowdown, PCT at 8.5 Ft. Elevation, Rods I thru 5 c:\1410w-2.wpf:1h092894 2-41
AP600 LARGE BREAM LOCA CASE 1 1300.
1200. -
L 1100.
W W
g 1000. -
8 900. -
I.J
$ 800. -
E .
Q.
700. -
Ib 5
r 600 'r
'4 -
500. -
4 400.
300.
/
- 20. 10. O. 10. 20. 30. 40.
TIME (SECONDS) 8 1
i Figure 2.2 23 Co=0.8 DECLG Blowdown, PCT at 10.0 Ft. Elevation, Rods 1 thru 5 l
u:\l410w-2.wpf:lt>092894 2-42 j
- - - _ _ __- . . ,_ _ _ _ _ _ _ _ . _ ~ _
l l l
APSDD LAAGE BAEAK LOCA CASE 1
] 9000 LJ m
g 900-m
-- 600-3 400' L
k 200' I
c D . : .
l 3 -200--
E
-400--
C
- -600--
O 000'- '
l I
-10D0 4L
-20 -10 0 10 20 30 TIME (SECONCS) 4 1
t
}
Figure 2.2-24 C3=0.8 DECLG Illowdown Top of Core Flow, Guide Tube Channel 2-43 I u:\l410w-2.wpf.15002894 I
l
\
\ _ _ _ _ _ _ _ _ _ _ _ _ _ .-
l
i I
l APGCO LAAGE BAEAC LOOA CASE 1
~
u 1000 W
g 800*
m 500-n O 400-L g's 200'
- J D ,
_N 200<-
e
-400--
~
~
-500'-
3 -800--
-1000 20 30 40
-20 -10 D 10 TtME (SECONQS} 3 Figure 2.2-25 Cn=4L8 DECLG Illowdown, Top of Core Flow, Open IIole/ Support Column Channel uM410w 23pf.It> tN 894 2-44 1 I
l l
l l
l l
ApBDD LAAGE DAEAK LOCA CASE 1 1000 N
p soo< -
"1
- 600-3 400' t
~
m 200-
}\
E M
o 4 M.M _
y -200-E
>_ -A00'
~
- -600-
~
o a
-DDD'
-20 -10 0 10 20 30 40 Tipe (SECONDS) 2 Figure 2.2-26 C3=0.8 DECLG Illowdown, Top of Core Flow, Peripheral Channel uainow 2.wpf.15m:8u 2-45 l
i i
f i
i f
i i
I Ap500 LAAGE BAEAK LOCA C#3E 1 ,
5 e - - y w
- 1. g j
.9-- f
.8-- j
. I
~ *
,7,.
a S !
[ .6-- !
)
[ .5--
O y 4-- l
.3-- .
.a.- l t
i
.1--
[
.I A . - .
- 20 0 to 40 60 80 100 120 ,
1 '
TIME (5EGOND53 ,
I i
l l
1 i
J Figure 2.2-27 Cn=0.8 DECLG Transient, Core Void Fraction Hot Assembly llottom, Midplane, Top u A1410w-2.wpf Ib4N2894 2-46 I
I
I APGDD LAAGE BR E Aut LOCA CASE 1 s
9'-
- 7 -
I :
C
'~
s.-
j 5'-
o A--
3 a--
g..
g ..
o 60 80 100 120 2D g 20 40 TIME CSECONCS) 3 l
l Figure 2.2-28 C3=0.8 DECLG Transient, Lower Plenum Liquid Ievel From Vessel Ilottom to Bottom of Active Fuel I ud1410,. 2 *pfA09:$94 2-47 l
i 1
i Apeoo L4 ace ensam toe, CASE 1 35 30-S es--
a W
w to--
J B
g $s.-
3 f so.- l 3 .
o ,,,
- so ao 3co reue cs,couas) ,
Figure 2.2 29 C ,=0.8 DECLG Transient, Downcorner Liquid Level From Ilottom of i
Annulus u:\l410w.2 upf;lb-012h94
i l
l l
l AASDQ LANGE B A E At: LOCA CASE i 14 12 N
h 10'"
d b
J 8<-
b 6--
3 4
g..
- ^ '
0 80 100 120
-20 0 20 40 SD TIME (SECON05) 5 Figure 2.2 30 Co=0.8 DECLG Transient, Core Ilot Assembly Liquid Level uA1410w 2.wpf.lb-097894 249
j
}
A b
l s
AP6DO LAAGE BREAK LOCA CASE 1 I
1800, i
{ 1200. -
f t
u W !
8 1000. -
9 '
W 000. - ;
3 C"
~
i
" i 6 600. 'I
- (
V 400. -
{_ -
20D. 30. 100. 120.
- 20. O. 20. 40. 80 TIME (SECONDS} 7 l
Figure 2.2-31 Cn=0.8 DECLG Transient, PCT at 6.0 Ft. Elevation, Rods I thru 5 uni 4 ow.2spt:iss2894 2-50
i l
l 1
APSOD LARGE BAEAK LOCA CASE i 1600. .
-t -
1400. -
L w
N 1200. -
S e
y 10CD.
5 E 900. -
y m
W ; --._-
5 7 ,
B00.-r 400. -
200 60. 80. 100. 120.
-20. C. 20. 40.
TfME (SECONDS} 5 Figure 2.2-32 Cp=0.8 DECLG Transient, PCT at 8.5 Ft. Elevation, Rods 1 thru 5 unr4 ow.23pr: wm4 2-51
. . , . . > - . w . . _ .. .
1 l
J 1
AP500 LARGE BAEAK LQCA CASE 1 g 1300. r 1200. '
6 1100. -
- W W
$ 1000. -
8 900. -
r W
W g 800. -
C
& d, Lsh 700. -
- n. Ml 5
e 600,-r-i :
i i 500. -
\i >
r 400. -
300
~# ' '
7, ,"";, *"
- 50. 80. 100. 12a.
i Figure 2.2-33 C,=0.8 DECLG Transient, PCT at 10.0 Ft. Elevation, Rods I thru 5 l
ui!410w-2.w;&lMF)2894 2 52 1 i
1 l
2.3 Conclusions The noding approach used on the AP600 plant is very similar to that used for the three- and four-loop ;
current plants as shown earlier. The loop noding is also consistent between the AP600 and the three-and four-loop plants.
The large-break LOCA transient behavior of the AP600 is similar to the current three-loop performance except for improved core cooling performance during blowdown due to the flow from the upper head region, resulting in significant rewetting of the fuel rods. The lower kw/ft. of the AP600 core design also results in reduced clad heat-up and the resulting peak cladding temperatures. The accumulator delivery is also prolonged in the AP600 due to the larger accumulator volume and the fact that both accumulators are available to inject into the reactor vessel, and one is not lost on the brokert loop, as in the three-loop calculation.
The passive safety systems have almost no influence on the resultant calculation behasior of the transient, with the exception of the accumulator, which exists in current plants. The flow that is injected from the CMT is only approximately 0.6 percent of the CMT inventory. This flow, which is injected early in the blowdown portion of the transient before the accumulators are on, will bypass the core through the break. Once the accumulators inject, they create significant back pressure to close the CMT injection line check-valve, terminating the CMT injection. Therefore, the larger accumulators in the AP600 design are the ECCS source responsible for terminating the clad temperature rise and the final quenching of the core. Since the new passive systems are essentially inactive (and in fact the PRHR is not even modeled in this analysis) for the large-break LOCA, the reponse of the AP600 to a large-break LOCA is very similar to that of an existing PWR, which WCOBRA/ TRAC is qualified to analyze.
u:\1410w-2mpf.ll>012894 2-53
3.0 SPECIFIC WCOBRA/ TRAC VALIDATION FOR UNIQUE AP600 FEATURES Introduction The phenomena identification ranking table (PIRT), given in Section 2.0, indicates that the main difference between the AP600 and existing PWRs is the direct vessel, or downcomer injection.
Additional specific validation has been prepared to examine the WCOBRA/TR.AC code capability to model the AP600 direct vessel injection into the downcomer. The additional validation for the thermal-hydraulic phenomena resulting from this type of injection is provided by application of the code to tests carried out on the cylindrical core test facility (CCTF) and upper plenum test facility (UPTF). This section presents the results of WCOBRA/ TRAC calculations of the CCTF and UPTF tests that simulate this emergency core cooling system (ECCS) arrangement.
3.1 CCTF Validation with Direct Vessel Injection 3.1.1 CCTF Facility Description The CCTF core-II is a large-scale experimental facility designed to study the system response of a four-loop PWR for loss-of-coolant transients (Figure 3.1-1). The facility is used to provide data on the thermal-hydraulic behavior in the primary system during the refill and reflood phases of a hypothetical loss-of-coolant accident (LOCA). CCTF has a flow area scaling of 1/21.4 of that of the reference four-loop PWR. The dimensions of the system components are provided in Table 3.11, where they are compared to those of a typical four-loop PWR.
The CCTF core-II represents a full-height (12-ft. heated length) core section with three intact loops and a fourth (broken) loop having a 200 percent break. The test vessel includes a downcomer, lower plenum, core region, and upper plenum with associated internals. He arrangement and dimensions for the vessel are shown in Figure 3.1-2. De configuration of the rods in the core and the upper plenum structure is shown in Figure 3.1-3.
He core has 32 rod bundles (8 x 8), each containing 57 electrically heated rods (0.421-in. outer diameter) and seven unheated and instrumented rods (0.543-in. outer diameter). De rods have a pitch of 0.563 in. Each heated rod has a nichrome heating element packed with magnesium oxide and boron nitride. The sheath is made of Inconel-600. The rods are held together by six grids, spaced at 26.2-in. intervals up the bundle.
The core is divided into the three main power zones: low, intermediate, and high, as shown in Figure 3.1-3a. The lower power zone consists of 16 bundles on the periphery of the core. The intermediate power zone consists of 12 bundles, and the high power zone consists of the four central bundles. Figure 3.1-3b shows that under guide tubes, there are four low-power bundles and six medium. power bundles; under support columns, there are eight low-power bundles and two high-uA1410w-3.mpf.B.092804 3-1
power bundles; and under open holes, it ere are four low-power bundles, six medium-power bundles, and two high-power bundles.
The axial power profile is shown in Figure 3.1-4. Also shown are the locations of rod thermocouples and spacer grids.
As shown in Figure 3.1-1, each loop contains a steam generator simulator (in fact, a single steam generator shell assembly houses two steam generator simulators), a pump simulator, and connecting pipework. Flow from the broken loop is discharged to 2 interconnected containment tanks via two blowdown valves, one connected to each break. Emergency core cooling system (ECCS) water can be injected either from two accumulator tanks or from a low-pressure coolant injection (LPCI) pump and its associated water storage tank to each cold leg. A hot leg injection system, which also has two accumulator tanks, can provide injection to each hot leg. In addition, a further injection system is available that can provide ECCS water to injection ports in the downcomer.
The CCTF core-Il facility is extensively instrumented. Instrumentation was supplied by Japan Atomic Energy Research Institute (JAERI) and the US Nuclear Regulatory Commission (NRC) and is briefly described below.
Rod temperatures are recorded by thermocouples located axially and radially throughout the core.
Additional thermocouples are also located in the core, upper plenum, lower plenum, downcomer, and the primary loops to record the wall and fluid temperatures.
Absolute and pressure difference measurements are obtained from pressure cells in the core, downcomer, lower plenum, and primary loops.
Liquid level measurements are obtained in four different ways: differential pressure readings; servo-manometer readings in containment tank-I; conductivity type liquid level detectors; and a fluid distribution grid (optical type liquid level detector) in the downcomer and upper plenum.
Mass flowrate measurements are made by electromagnetic flow meters for ECCS mass flow; drag disks for flow between the downcomer and core; a venturi tube for the steam vented from containment tank-II; and turbine meters for the flow in the upper plenum, end-box region, and through the vent valves (not used). Velocimeters are used to give the fluid velocity (and hence core flooding rate) in the lower plenum. Spool piece instruments are used to obtain fluid densities, velocities, mass flowrates, and void fractions in the loops. Power sensors record the power level of the rods. More details of the CCTF core-Il facility can be found in the Data Report on Large Scale Reflood Test-78.*
unl410w-3.wpf;1b-092894 3-2
1 t
3.1.2 Test Description Test C2-AA2 (run 58) was selected for analysis. This test models downcomer injection as part of the ECCS, similar to the AP600 design.
Figure 3.1-5 shows the sequence of events for the test, and Table 3.1-2 contains a summary of the initial and boundary conditions.
De primary system was heated with preheaters to its specified temperature of 248 F and pressurized to 29 psi with steam. De water in the low-pressure coolant injection (LPCI) tanks and accumulator tanks was heated to its specified temperature of 95*F. The LPCI water was circulated to ensure that the injection lines were at the same temperature. The accumulator tanks were pressurized with nitrogen to give sufficient head for the required injection flow. The steam generator secondary fluid was also heated and pressurized. The heaters were then turned off, and the lower plenum was filled to a level of 2.82 ft. When the initial conditions had been established, power was applied to the heater rods, and the data recording was started. He heater rods were then heated under near-adiabatic conditions until the clad temperature of four rods had reached 1331*F.
At 85.5 seconds, accumulator injection to the lower plenum and the downcomer injection ports was initiated. When the water had reached the bottom of the heated length of the core, the rod power decay sequence was initiated. The water injection to the lower plenum was redirected to the cold legs at 97 seconds. . lust before the end of accumulator injection to the cold legs at 116 seconds, LPCI flow was initiated to the cold legs and maintained for the remainder of the test. Downcomer injection was also maintained for the same period.
He generated steam and the entrained water flowed via the broken loop to the contaimnent tanks.
He steam was vented to the atmosphere to maintain a constant pressure in the containment tanks.
After all the thermocouples on the surface of the heater rods had indicated quenching, the power supply to the heater rods and the ECCS water injection were turned off. Then the recording system was stopped, terminating the test.
3.1.3 Test Results De water level in the downcomer rapidly increased after 112 seconds as the main accumulator injection flow reached the vessel via the cold legs and the downcomer injection. By 150 seconds, the water level in the downcomer had stabilized and was maintained at ~21.3 ft. by the downcomer injection and LPCI flows. His level provided the hydraulic head necessary to achieve the core reflood Water first entered the core as a result of the rise in water level in the downcomer. De initial surge of liquid into the core was sufficient to quench the lowest elevations of the rods throughout the core.
After this tJme, the flow into the core became oscillatory as steam production, and the resultant core ;
l u:ucow-3.wputvons94 3-3 l
i l
pressurization counteracted the hydraulic head ofliquid in the downcomer. The rods at mid and upper elevations continued to heat up until they were cooled by the enhanced heat transfer in the proximity of the quench front. The peak clad temperature of 1582*F was recorded at 152 seconds,6 ft. above the bottom of the heated length. The quench front progression up the core was directly related to the i
power level in the rod bundles. The central high-powered bundles quenched up to 100 seconds later than the low-powered periphery rod bundles. A total core quench was achieved at 772 seconds. ,
t 3.1.4 WCOBRAffRAC CCTF Afodel l The .}VCOBRAfrRAC model of CCTF uses a one-dimensional mesh for the loops and employs a l sub-channel formulated three-dimensional mesh for the pressure vessel. The axial momentum equation' !
is retained in a standard form, and the two transverse momentum equations are combined to give a j single transverse momentum equation that is applied to each transverse (gap) connection irrespective of l its orientation within the transverse plane.
First, the vessel component model is described. This is followed by a description of the !
one-dimensional loop nodalization. j r
3.1.4.1 WCOBRA/ TRAC Vessel Component hfodel (
(
A noding diagram of the vessel model used in the analysis is shown in Figure 3.1-6. It shows the channel and interchannel connections (gaps). [
ju The noding used in the CCTF downcomer injection test model is consistent with that used in the AP600 plant model. [
]"
[
3u The arrangement of four channels in the core regions [ ]" was chosen to model the different power regions within the core and also to lump together regions of the core that share a similar ty[x: of geometry due to their position in relation to guide tubes, support columns, and open flow holes in the upper core support plate.
uA1410w-3,wpf:1b-092894 3-4
i Grouped together are low-powered bundles below support columns (channel 14), low-powered and medium-powered bundles below the open hole regions of the upper core support plate (channel 15),
and low- and medium-powered bundles below guide tubes (channel 16). The high-power bundles are represented by channel 17.
Six WCOBRAffRAC rods are used to model the 1824 fuel rod simulators. Table 3.1-3 shows which rods and bundles they each represent and to which core channels they are connected. Channels 8 to 13 form the downcomer annulus at this elevation.
[
)c
[
)e I
ju
(
)c The fuel rod simulators and solid structures within the vessel component are modeled using the rod and unheated conductor models.
l 1
u A1410w-3.wpf:lt>-092894 3-5 l
l
1 l
3.1.4.2 One-Dimensional Component Models e A diagram of the one-dimensional components used to model the CCTF loops is shown in Figure 3.1-15. [
i ja.e Each of the cold leg and hot leg PIPES is broken into mesh cell lengths such that no one cell produces >
an overly restrictive limit on the time step due to the Courant limitation. De length and elevation to and from the pipe wall is included by representing the pipe wall by two radial heat transfer nodes.
I
] Since the CCTF facility maintains prototypical piping lengths, the loop node sizes are similar to those for VRA and the AP600.
I j=c he steam generator components are modeled with the secondary side divided into [
] The flow area of these nodes is equal to the flow area of a single tube multiplied by the number of tubes in the tube bundle. The volume of the inlet plenum modeled corresp(mds to the physical volume of the plenum. De height of the plenum is set equal to the vertical distance from the top of the tube sheet to the outside bottom surface of the shell to conserve elevation. He distance between the shell bottom and the cold leg centerline is modeled as part of the cold and hot leg PIPES. The area of the junction connecting the plenum to the piping is set equal to the area of the connecting pipes in the facility. The top area of the plenum is set equal to the tube bundle area.
[
Jax a:\1410w-3 upf:lt>-092894 3-6
1 3.1.5 WCOBRAffRAC Calculation and Data Comparisons
)
, The calculation simulated the experiment from 85 seconds, immediately prior to the start of ;
accumulator injection, to the end of the test at 850 seconds. He calculation was started at this time to :
achieve a more accurate representation of the rod temperatures before the reflood phase of th l experiment had begun. Figures 3.1-16 to 3.1-50 compare the calculated results to the experimental !
data. All the figures, except Figures 3.1-31 to 3.1-33, reference the start of the experiment as time l zero on the 'x' axis. He calculated results are plotted from 85 seconds. Figures 3.1-31 to 3.1-33 depict the quench envelopes that reference the beginning of core recovery (BOCREC) as time zero on the 'x' axis. BOCREC occurred at 93 seconds. i The experimental data are represented by digitized plot profiles in all the figures except the heater rod i temperatures due to a corruption of the datatape. He digitized plots are simple averaged representations of the data and do not depict the fluctuations that occurred in the experimental readings. To aid the reader, each plot references the figure number used in the full data report.O i
A review of the experimental heater rod thermocouple data shows that the thermal response across the core is dominated by the power rating of the individual rod assemblies. Rod assemblies of equal l power rating exhibited very similar behavior. Their position in the core relative to the geometric !
configurations (open hole, support column, or guide tube) in the upper support plate had no significant l influence on the results. De data from three assemblies, representing the three different power levels {
in the core, were selected to compare against the calculated temperatures of rods 1,3, and 6. Rods 1, . j 3, and 6 model low , medium , and high-powered regions in the core, respectively. Rod 3, however, !
is grouped with rod 2, a low-powered rod, in channel 15 (Table 3.1-3). Therefore,it is to be expected that the thermal response of rod 3 will be reduced due to the influence of rod 2 on the common fluid j conditions. ;
i Re calculated clad temperatures for the low , medium , and high-powered rods are compared against f the data in Figures 3.1-16 to 3.1-30. De clad temperature histories are given at five elevations, j I
1.25 ft.,3.33 ft.,6 ft.,8 ft., and 10 ft. The clad temperature comparisons for the low-powered rod (Figures 3.1-16 to 3.1-20) show that the lower elevations quench out earlier in the calculation, although the prediction of the maximum clad temperatures at each of the lower elevations is good. As l the transient progresses, the degree of subcooling at the quench front reduces to zero. As a consequence, the calculated rate of the quench front progression reduces below that seen in the experiment (Figure 3.1-31). The reasons for the change in the calculated rate of quench front progression are as follows. At mid elevations, the power rating is large, and the liquid subcooling at the quench front is reduced to zero. This can produce high calculated steam flows as the channel cells l fill with water, which are sufficient to drag liquid slugs from the quench front. The liquid slugs pass j out of the core, causing a reduction in the core collapsed liquid level, which tends to reduce the ;
quench front progression. Because the surface area of the liquid slugs is relatively small, the interfacial heat transfer is low. After 420 seconds, the calculation underpredicts the experimental !
quench front elevation, the cross-over point occurring at ~7.5 ft. De quench front progression is well j predicted from 300 seconds to 500 seconds and this leads to a good prediction of the 8-ft. elevation i i
u A1410w.3.wpf db-M2894 3-7
temperature. The 10-ft. elevation is calculated to be partially quenched by the liquid slugs passing out of the core, and the temperature is underpredicted from 440 seconds to 600 seconds, although the final quench is calculated to be delayed.
The rod temperature comparisons for the medium- and high-powered rods are shown in Figures 3.1-21 to 3.1-30. The influence of the predicted quench front progressions (Figures 3.1-32 and 3.1-33) again have a pronounced effect on the calculated clad temperature histories. 'Ihe higher clad temperatures associated with the higher rated rods tend to cause the loss of subcooling at the quench front to occur earlier and at lower elevations. The reduction in the predicted quench front progression therefore occurs earlier compared to the low-powered rod. This allows the clad temperatures at upper elevations to increase significantly higher than the experimental temperatures, especially for the high-powered rod
~
(Figure 3.1-30). The experimental peak clad temperature (PCT) of 1582*F was recorded by thermocouple TE31Y17 at 152 seconds (Figure 3.1-28). This thermocouple was located at the 6-ft.
elevation in one of the four high-powered assemblies (assembly 31). The calculated PCT of 1684*F is predicted after 264 seconds at the 7.94 ft. elevation. The calculated PCT occurs 105 seconds later than the experiment and is located 2 ft. higher. This agrees with the underprediction of the quench front progression later in the transient, which promotes excessively high rod temperatures at upper elevations, especially for the high-powered rods.
The upper plenum pressure history is shown in Figure 3.1-34. The downcomer differential pressure is plotted in Figure 3.1-35. This figure indicates that the downcomer quickly fills with water after the initiation of accumulator injection at 85.5 seconds. The water level is maintained up to the height of the cold leg nozzles by the low-pressure coolant injection (LPCI) and the downcomer injection. The WCOBRA/ TRAC calculation accurately predicts this filling sequence. The hydraulic head of water in the downcomer provides the necessary driving pressure to force the water into the core and initiate the core reflood. Figure 3.1-36 shows the core differential pressure. The agreement between the calculated results and the data is very good up to 300 seconds. After this time, the calculation is slightly below the data. This indicates that the core water level is slightly underpredicted after this time. This may be related to the flow behavior at the quench front, which is discussed later in connection with the thermal response of the core. After the initial pressure htuations that correspond to the start of the core reflood (~90 seconds), the calculation continuausly underpredicts the pressure data for the duration of the test. This discrepancy becomes smaller as the transient progresses. The reason for the difference is the underprediction of the pressure loss M ine upper plenum to the containment tank (Figure 3.1-37). One of the main contributors to this pressure loss is the pump simulator in the broken loop (loop 4 in the calculation). The pressure loss across the pump simulator is shown in Figure 3.1-39. The experimental and calculated water and steam mass flows passing through the pump simulator are shown in Figures 3.1-42 and 3.1-43, respectively. The calculated steam and water flows are less than the corresponding experimental flows. It is these reduced flows that cause the underprediction of the pressure loss along the pump side broken loop (i.e., hot leg pipe, steam generator simulator, loop seal pipe, pump simulator and cold leg pipe to the containment tank).
The steam and water mass flows in the hot leg of the broken loop are shown in Figures 3.1-46 and 3.1-47, respectively. The calculation underpredicts the degree of liquid entrainment passing from the u A1410w.3.mpf;1b-o92894 3-8 s=
l upper plenum into the hot leg for the majority of the test. The lower calculated water mass flow has an effect on condensation of steam and results in higher calculated steam mass flows compared to the data. As the water flows in to the steam generator simulator, the water evaporates, creating more steam. This results in the experimental steam flow increasing above the calculated flow downstream of the steam generator simulator, as shown in Figure 3.1-43. Evidence oflower calculated water flow in the pump side broken loop is also obtained from the fluid tereperature comparisons in the hot leg and loop seal pipe (Figures 3.1-49 and 3.1-50). In Figure 3.1-49, the calculated temperatures are above saturation, whereas the experimental fluid temperatures remain at saturation indicating the' >
presence of more liquid. De higher saturation temperature in the experiment correspond to the higher pressure in the broken loop compared to that of the calculation. The temperature difference is more pronounced in the loop seal pipe (Figure 3.1-50).
The experimental data show that the intact loop flows exhibit similar behavior. The flows in loop 1 were selected for comparison and are shown in Figures 3.1-40, 3.1-41, 3.1-44 and 3.1-45. The calculated hot leg steam flows are in close agreement with the data up to 300 seconds. After this time, the calculated steam flow remains at a fairly constant level, whereas the experimental steam flow reduces as a result of increased condensation corresponding to the higher water mass flow (Figure 3.1-44). The steam flows are in closer agreement towards the end of the test when the calculated water mass flow accurately represents the data. The calculated cold leg mass flows are compared to the data in Figures 3.1-40 and 3.1-41. The calculated accumulator injection into the cold leg is in close agreement with the data. This flow dominates the plot and no usefulinformation can be extracted from the comparison for the remainder of the test he calculation overpredicts the cold leg steam flow, as shown in Figure 3.1-41. The differential pressure across the pump simulator in loop 1 (Figure 3.1-38) is, however, in closer agreement, indicating that the experimental water mass flow may be greater than the calculated flow.
The experimental and calculated broken cold leg vessel side fluid temperatures are compared in Figure 3.1-48. The calculation and the data show the fluid to be at saturation temperature, indicating that water is spilling from the downcomer into the broken leg and subsequently, flowing to the break.
The saturation temperature in the data is higher than the calculated saturation temperature, indicating that the system pressure is higher in the experiment.
3.1.6 Summary De calculation provides a reasonable prediction of the thermal-hydraulic behavior in CCTF run 58.
Nothing unusual or different from other CCTF with accumulator injection in only the cold legs was observed. Downcomer filling and core flows are in close agreement with the data. The calculated entrained flows in the broken loops are lower than the data. This results in an underprediction of the system pressure as a consequence of smaller calculated pressure losses in the broken loops. The maximum clad temperatures in the lower half of the core are well predicted. The modeling of the fluid hydraulics at tl e quench front produce a conservative prediction of the clad temperatures at upper elevations. The WCOBRAfrRAC calculation predicted this panicular test with the same precision as the cold leg injection CC'IF tests, as shown in the CQD.*
u:\l410w 3.wpf.lb-092894 3-9
. .. . . . - - _ = - . ~ . - . - . . - . . - - .. . - . - - - . . . - _ . - . . - . - . .
i TABLE 3.11 l f
COMPONENT DIMENSIONS OF CCTF COMPARED TO PWR Component PWR CCTF Ratio l i
PRESSURE VESSEL ;
Vessel Inside Diameter (in.) 173.0 42.7 Vessel Thickness On.) 8.5 3.54 l Core Barrel Outside Diameter Gn.) 152.5 37.8 Core Barrel Inside Diameter On.) 148.0 36.6
- Thermal Shield Outside Diameter (in.) 164.2 Thermal Shield Inside Diameter (in.) 158.7 .
i Downcomer Length On.) 190.9 190.9 1/1 Downcomer Gap On.) 4.5 2.4 :'
Downcomer (+ Baffle) Flow Area (ft.2) 45.5 2.12 1/21.44 Lower Plenum Volume (ft.') 1045.3 48.73 1/21.44 2
Upper Plenum Volume (ft.') 1539.7 72.0 1/21.44 FUEL (HEATL ROD ,
Number of Bundles (-) 193 32 ,
Rod Array (-) 15 x 15 8x8 ,
Rod Heated I.ength On.) 144.0 144.0 1/1 [
Rod Pitch (in.) 0.563 0.563 1/1 l Fuel Rod Outside Diameter (in.) 0.422 0.421 1/1 !
Thimble Tube Diameter On.) 0.546 0.543 1/1 l Instrument Tube Diameter On.) 0.546 0.543 1/1 Number of Heater Rods (-) 39372 1824 1/21.58 Number of Non-Heated Rods (-) 4053 224 1/18.09 Core Flow Area (ft.2) 56.9 2.7 1/21.2 Core Fluid Volume (ft.8) 633.9 32.2 1/19.6 .!
PRIMARY LOOP ,
Hot I.eg Inside Diameter (in.) 29.0 6.11 1/4.75 ;
Hot Leg Flow Area (ft.2) 4.59 0.205 1/22.54 }
Hot leg Length On.) 155.1 155.1 1/1 r Pump Suction Inside Diameter (in.) 31.0 6.1 1/5.07 Pump Suction Flow Area (ft.2) 5.24 0.205 1/25.77 Pump Suction Length On.) 313.0 313 1/1 l
1 u A1410w-3.mpf.lb-092894 3-10 i
TABLE 3.1-2 ;
CCTF TEST CONDITIONS PCTat l Total start of System Test Power Radial Power reflood Pressure ECCS Flowrate Location No. (MW) Power Decay A:B:C ('F) (psi) and Durstion 58 936 ANSx1.2 + 1.36:1.2:0.76 1467 '1467 (1) Acc. flow to lower :
1.1xActinide plenum 2.86 ft'/sec.
from 85.5 to 103 sec.
(2) Acc flow to cold legs i 2.86 ft'/sec, from i 87.5 to 11.3 sec. ;
(3) LPCI flow to cold legs 0.0777 ft'/sec.
from 85.5 to 1008 seC.
(4) Downcomer injection 0.3143 ft'/sec. from 85.5 to 1008 sec, i
TABLE 3.13 !
CCTF ROD-TO-CHANNEL CONNECTIONS !
Core Channel No. of Fuel Rod '
WCOBRA/ TRAC in which Rod Description of Assemblies Represented by Simulators Rod No. is Located the Rod Represented i 8 low-power assemblics under suppon 1 14 columns 456 2 15 4 low-power assemblies under open holes 228 3 15 6 medium-power assemblies under open boles 342 !
4 16 4 low-power assemblies under guide tubes 228 i
5 16 6 medium-power assemblies under guide tubes 342 6 17 4 high-power assemblies 228 l
l u A1410 -3. pf.1b-042894 3-11
l l
TABLE 3.1-4 NOMINAL STEAM AND ECCS INJECflON RATES ECCS Run/ Phase / Evaluation Subphase Period 1 2 Core SG Tm Tse, (seconds) (Ib/s) (Ib/s) ( F) ('F) 272 A 57 - 81 2011 2006 496 196 93 211 274 BI 59 - 108 1863 1884 459 198 257 101 274 BU 280 - 324 1951 0 227 0 257 56 274 BUI 337.5 - 344.5 1951 1840 225 0 257 47 u A1410w-3.upf:lt>4i92894 3-12 l
1
__---- __________.______________________._____________________J _
i 5
Ee ao M i w
h l Hl s k$_o W"
j a-$
J $
~E s_ _ +=m - a @
ll' E "s-Mon K a ;
p-VA_,
Yv '
v '
N I
k) g7
[' I .s -=
52 8
C ,
l 2
l i h cx 7
m5 m
.c g m= 1 Figure 3.1-1 CCTF Core-II Test Facility uil410w-3.upf;1b-092894 3-12
________________________________________..__.______________.____._._____._____.____a
{ l Upper head Upper stoport piare +
Upper ring b ~E Sorten of support plate 1264 8 qj Vent volve % /".~
1084W e 961 8
~
9d9 8 l
~ _J Core Mng nozde\, g ,, .,,,,,,
P ""~L W me separt plare\ {
Downcomer g , Bottom of core plate N -
R Top of heated section Core g '
s Boffie region g '
N @
N .
I S
Borrel g s
j Lower core support plate g -
s .
N I R eBottom of hooted section
\ op T of core ptote Lower grid g - y s
N
. . Barsom of grid ,
S as Sortom piore s - -
f N le . l I % i unit men I
Figure 3.1-2 Diagram of CCTF Pressure Vessel
. ~ . .
u$1410w-3.*pf:Ib-092894 3.],$
- ._. = . _ - . . . --_ -.
t 9N i
wM
.%...,,,,,, .th.gh. m me.
m%
' m m .
I,"!~" ~~,
=%
A B C ;
i i
c.= = w4 i.n '
ftet Irg "'I' M b.E $
w: Wese eseue Figure 3.1-3a Cross Section of CCTF Pressure Vessel ,
Fil ,
I J.
O 5
- aa-
~~
@. t
,,,- O o. -
c.w seg O O wg ,
O O O O O O l
Ces W W OO W
sma av a.,
annun.ner w
= i., w%
w: me seemi l
Figure 3.1-3b Cross Section of CCTF Upper Plenum u:\1410w 3 wpf:1tr092894 3-15 I
I j
l UCSP d$$ 1 Te plose x.. INS Spacer 6 g
3660 ass. -
i O, !
340$
3:$5
$ 9 0 2945 2745 Spa:er 4 L 2544 [!6l <
8 9
~
- 2335 A~
8
^
2135 R. G o e N' *3 s a in5 S.
k im '
E k i
,m 9 !3h ' Wr 2 l 8'
nis
-l f,
- f'- sis E
~ $ TIS jj$ - Spaar i h E o . .
505
$ 8 n
ci 2ss h $
u o d
.jj,
- LCSP I.O 0.5 0 Power ratio Unit: mm Figure 3.14 Axial Power Profile of Heated Rods in CCTF Core u A1410w.3.wpf:lb-W2894 3-16 l
l l
i l
i Data recording i I
Reflood initiation : 93s (1466*F)
, ,...I....,'~
/ ,- Clad temperature
-Power ',
j /
i : \*
/ . All quench V
t/ :
'l .
Power off
- . . . . . . . . . . . . . . . . . . . . . . . ... .T.. .e
. . s. t.e. n. d.
- 1me
' 722 1008 1038 0 85.5 Acc injection to lower plenum (2.86 f t8 /s)
Acc injection to cold lege (7.86 f f /s)
/ [ Downcomer injection (0.3143 f 8/s)
LPCI to cold legs (0.0777 f t*/s
/
r i i r
time 1008 ;
0 85.5 97.0 111 Figure 3.15 Test Sequence of Test C2.AA2 (Run 58)
=A14 tow-3.sgIb-092894 3 17 i
i
i a.c l
1 l
l i
l l
l 1
l i
1 Figure 3.1-6 WCOllRAffRAC CCTF Vessel Noding Plan View unt 410w-33pf.15092894 3-18
a,c Figure 3.1-7 WCOBRAffRAC CCTF Lower Plenum Noding (Section 1) n:\1410w-3.wpf:Ib-002894 3-19
l 1
l a,c I
\
l 1
I I
l Figure 3.1-8 WCollRAffRAC CCTF Core Region Noding (Section 2) nAt410w 33pf:I w w:894 3-20
l l
l i
i a,e l
i l
1 l
i l
1 i
Figure 3.1-9 WCOBRAffRAC CCTF Tie-Plate Region Noding (Section 3) j i
l uA1410w-3*pf:tho92894 3-21 i
i
l l
a,C I,
Figure 3.110 WCOBRA/ TRAC CCTF Upper Plenum Region Noding (Section 4) ud1410w-3.wpf:ltr@2894 3 22
_ h
l l
1 a,C 1
l I
l l
l Figure 3.1-11 WCOBRA/ TRAC CCTF Upper Plenum Region Noding (Section 5) uA1410w.3.wpf:1b-@2894 3-23 ,
1 l
a,c ,
i i
i I
Figure 3.1-12 lVCOBRA/IRAC CCIT tmp Connection Region Noding (Section 6) a:u4to. 3. pt:n>o>2894 3-24
a,c 0
5 l
I l
l l
Figure 3.113 WCOBRA/ TRAC CCIT Upper llead Region Noding (Section 7) n:\1410w-3.wpf:1b-C92894 3-25
a,c l
i i
l i
l l
~
l Figure 3.114 WCOBRAfrRAC CCTF Downcomer Channel Arrangement uni 4 tow-3.wpf 1t>o9:394 3-26 i 1
I
a,c j
l Figure 3.1-15 WCOBRAffRAC CCFF Loop Noding Diagram u Al 410w-3.wpf:ltr092894 3-27
_ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __J
_ JO3 Qo3W&wO E8 l U_J<O wwQWg<HD&w 4- - NLD "e vQWO Ln L
. h e
F i
g u
r e
3 .
1
_ 1 6
C
_- C T
F .
R u
n 5
_. ,8 L
o w-P o
- w e
r e
d R
o
,d C
l a _
d T
e m
p % ,,
e .
r s a
t s _
u _
r s e .
a t
ir 1 '
iil i
, , : ; 'i l 1 :- !4 i ;'
s 2 _ _
5 f
t 3 y k 4 DE g DR A5O pM C0 A5C G n A5D G n pg *0 ad L
~ad _
u '.8"8w4 W5 s6W E 0i_ ' b N 9
- . if !!! i ' 'i< - ' 1
': ! ', : , L F; ! ! .
a b
[ LOW POWERED ROD - CLAD TEMPERATURE AT 3 33 fL (DEG F) j 's CC T 2000-
$ 21 T E
$ 3 o w
- 1800-t n
g iete-m W
c 8 1400-rO
- ! I200-c Y
ra 4
e m g 1000-x O
o.
Q n :
E. ,
N H I
$ 800- [ t 3 p i i t j k l m
[ '
/ L_' .. _ _ _ . . _ _ _ _ ._ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
{ b 200 0 ide 2de 350 Ade 5de ede 7de ede-
- p ,
x-Axis Tac Y-AXIS C13 Tt2.AD13 DATA T_T01 : I CALCLULTIIN FROM 85 TC
- DPT DATA TEOt YIS WIG C-1, FET 2. I >
Y-AXIS Ct"I T001Yl5 DATA FILE 2 - - - - ,
h
______._________-___________,.,m_v ---..r-w, -,. ._.-w. _-__.___...,__..,.,-o .v. . . , , , , _ ,n.-. ,-. , r- . . , - , , , .. . . _ . . , ,
w - .,, , . . , -, , .w ,, ,, , , , -,y._.,
e f
4 KT LOW POWERED ROD - CLAD TEMPERATURE AT 6 fE (DEG F) am
$ 21 8 i!
E a W 1000-Y w
i oc i
t FIO-l %
5 t400-
.a F
j 13D-w k - *
& y o , ..
t000- s, Q s S / ,
% , t o g a /
t 000- I O \
E I I
G H I a m /
I O '
T i i
g '
N e
- l i N I _
ch i i i i e
% 2CC i 300 40 S00 000 700 BCO O 1be 200 X-AXIS THE CEO.t AT194 FTECM 85 IC Y-AXIS Cl'l TCUOI6 DATA St : I - D PT DATA TEUI Y17 (FIU C-1, FET 2 1 >
Y-AXIS Ct3 TEDIYl7 CATA FIlf 2 --
n G
$ LOW POWERED ROD - CLAD TEMPERATURE AT 8 ft (DEG F)
L
-j wr 20W C 9
? R' 5 E E 9 IN L
e a t000-O H
m h
n te
{ 1200-y 4 g <,,.--- ,
W $ /
~
4 i033- -
y .,
c.
N .
$. m \
,' s
=
- o. I g
.-]
n TJ0- /
3 '
j
}, t E an- ' '
,R
, \. _ _ _ _
N / W 0 100 20 ' U X-AXIS MC Y-AXIS Cl] IU ADIS DATA MI 1 C4_Od_ATID8 FFOi E3 E DATA TEDIY19 (FID C-1, FEF 2 1)
Y-AXIS Cl3 TE01Y19 DATA N 2 -- -- -
u -
\
1 4
1 0
w-4 03 O3W O Q'OO I UJ4O H Iab4 DgLd 4g 9 c v$C Lnt F
m p h 0 F 1 i b- g 0
9 u 2 r 8
9 e
4 3 1
2 0
C C
T F
R u
n 5
,8 L
o w- d P
3
- o 3 w 2 e r
e d
R \
i i,' e
'i o '
' i '
- I
,d s ,
C l
a d
e/
o
<j
/
i T
e -
p m s' e ,
r a
t -
u '
r e ' -
a t ' - I i ,-'
1 s 0 -
f t
J o
~8 g g g
3 h A p $
s uC ok< ~
>$ v Oi b n
> uD s< b< N 8 , 1 ,
ad
u.
s t
4
<s t L o
w- Oh 3WxfWO GOO o_J4O &WcLLW&4 -)"W gto Wo *8 LA 4
w F i
h p g r
u lb r e
m 3 n9 1 4 - -b 2
1 C
C -h T
F R
u n -h 5
,8 M
e d
i
-k u
m-3
- P 3 o -h 3 w e
r -
e d
R b o
,d k, C
l a
d b s T
e '
m -
p .,
e h -
r '
a t
u
- , < . , ' ii ;
j
_ _ _ _ _ _ - - - - _ ~ - . _ _ = - -
- . _ _ . _ . - _ _ _ _ _ _ - . - - - - _ - _ - . . -. - - _ _ . - . _ _ _ _ . _ -- - _ - - - _ - _ _ - _ _ _ _ _ _ _ . . - - ~ = - _ .
C d
[ MEDIUM POWERED ROD - CLAD TEMPERATURE AT 6 ft (DEG F) 2 , mr g g. axe E
.h. ~
U i
a y lete N
O O tesn H
9 5 5 4w / 's,
'e N,
W i
O" IM S- I '
e
- t u h -
w m C IN i
(Ji g
$ \
Q l L ,
M N I
- I l g
- t I
O
- iT w
- i y
e i i s
R an l 9 ' ) __t e ' wr-3 E i e i i i p
- 0 i
103 200 i i 300 @ W M 700 ECD E x-AXIS THE Y-AXIS ClJ TRACOS DATA Di CALCLt.ATIUJ FRO 185 TC P - CWT DATA TE17Yl7 (FIG C-E6, RT 2 1)
Y-AXIS C1] TEl7Y17 DATA FILE 3 -- --
u:
u 4
10 w .
~WOH5 23WOuO &@ , UJk &uo4yg<+
'J J w<l " o v b O u_ n 4
4 N pt F i
i g b- u o r 2
9 e 8
9 3 4 1 2
4 C
C T
F R '.
- u l n /
5
,8
/ /
/
M e '
/
- d .
ui 'l, m
3 3
6 P
o w
e r - .
e d .
/
[
R ' ,
o - -
,d C
l a
d T
e m
p e '
r a
t - .
'1 ls e u .
r e N -
- _ b-a t o 8 @
k
$ ge g h g 8 a2n ew E,. @
f >;tTc D - 8S WE -
- t. lse G - e5e8S n8 i 't ,84
. - W 5- @ u$ b ~ C 1 l ) i '
E E
MEDIUM POWERED ROD - CLAD TEMPERATURE AT 10 fE (DEG F)
{ CC T e m 200>-
$ g e
u w f L i eo>-
h W
O O isn-H M
M e
D 14R m
N L, 'M ~ ~ ~
,, ~~
? e
- *s O g ian- , .,
n ,- .
f cu s,
% N
's C / s
\
. /
C / . \
E * ' i
, i e
- r 9
?, an-- ' s i
l
~ # ~ k_
c O W 2CC i s e i i i g i
- O 100 200 e
NO 430 '500 GD '70 0 000
$ x-AXIS TWE Y-AXIS CIJ TO.AO310 DATA #CT08 I CALO.4_AT104 FFOt 535 *EC p
. Y-AXIS Cl] TCl7YlA DATA FILE 3 -- -- E>PT DATA TEl7y t A rJ10 C-(Z5. & 2 1)
S E
-F HIGH POWERED ROD - CLAD TEMPERATURE AT 1 25 Ft CDEG F)
L e CE 7
% 3 c W-Y E sy a b $ I800-h Ch h
H IECO-
"f1 te
?
h 'N T
m ta o
$ 3N Q
3.
x N
-a ,i + ,
O w
s
% f \ .
4 W /
n i 3 I m
I I
& I f
@ / I - . - - - -- -- - - --._- g _ -- _ _ - _ _ _ _ _ _ _ _ _ .
2 = , , . , , , , ,"
0 ICU 200 M 40 SCO OCO WU 000 y
- X-AXIS TDE 2 Y-AXIS Cf3 TOA61 DATA mi t CALCt.t.AT1U4 FIU185 MI Y-AXIS ClJ TE31Y43 CATA FRf 2-- -- - OPT DATA TE31Y43 CFIG C-123, FET 2 1)
u a
1 4
1 0
w- IgOI CO3Wyo "8 ,U_J<Q - HW W&<#W;t J 4F m Mm w.a vQWo im t 4
.w h p F f
. i k
l g b- u 0 r 2
0 e
8 9 3 4 1
-h 2
7 C
C -
T F
R u -h n
5
,8 l
i -
gi - ,
h-P ' '
3 o 3
w - :
9 e - - .
r e >
d , ,
R ' ',
o
,d ' '
Cl a - -
d T
e - -
m - -
p e
r . -
at . -
u r
e - a] 'i i i i1 , i 2 i I ' 1 ! i i ; <
i a
t k - -
3 3 o
-B sp' g eP f9 e8 3 x{D hu f x{D C n $4 - -
Ue,. g $
.t
>jQ G n h- -r $e n i i i i , UL 8d Wg h Vh 05 - N^
I 1ll l l1 l 'i ll1 l
-l '1 , ,i 11l1II
u M
14 0
w -
IsOrko2WNO W9 ;U.<argzWW<w$W )t 4s 4m 'OWO u_ n 4
w h p
f I
t Fi g
0 u 0
2 r 8
9 e
4 3 1
2 8
C C
T F
R u
n 5
,8 '
\.>: .. ,,
I - e, I .
i "
g _
h
- _ f.--
3 P ,
4
(
)
- o w '
e .
r e
d R .
o '
.d ' -
C l ' -
a -
d -
T e
m -
p -
e _'
r a
t u - - d,'
r >, s r ' , . il i i ,6 i' ii 'i e
a t
~ -
g f
g
^ _h eR 6 e k f 4#C Ou B9
.t 82 sB i5Q G n i2Q G n 0bs80 -
t
- DR 8e 'WR ~ U9 u -.bN ^
~
M c
Y HIGH POWERED ROD - CLAD TEMPERATURE AT 8 Ft (DEG F) 4 Tr c m Kny J g 3 E
? *a
- 1&
ek T
O 1(U)-
- T1 ./,,-s=, **
lC ,
c
- O ie m #
tp 's '
? 's, M taw 's %
? I '
W T I ~.
L o
s ' '.
10 & g -
's
- c.
- s g
c I ',
SM- '
E g r '
Q w '
1 y i 8 H I i
B y I I
O #
c 1
l 5 t a__ __
t
'rt g ,
200 M eh 5de d 7de f 00 O tbo b
,2 <-AXIS TDC CALO.L ATIU4 N1 EG TC
(-A.<IS Ci 3 TU ACCO 0%TA TT01 1 -- CPT DATA TC31Y19 UTG C-121, Ff7 2 l >
s'-O:IS Cl1 TE3t Yt9 DATA Fnf 3
d I
o
[
HIGH POWERED ROD - CLAD TEMPERATURE AT 10 ft (DEG F) a, ccr m m f 5' 3 C
's A 2 ? s t<n 7
w C
IGD N
e se D
f
/ .- - - ~ ~ , , -
= iam e' y ,
u .
- 1. ia.
m ,
Go , '
s N f
% y ,
' s O s g, ,
i y sw i e o I
f e@ f h @ I I
g q-k ,
I ~- - -
~ ,
$ 0 100 i i "XV s
300 @
i i 500 OCO 7dc b a <-Axts ruc
- Y-AXIS C13 TELAC6to carA eET01 CALCLA.ATID4 FTO165 Sir y-duIS CI J TE31YIA CATA m 3 -- - E>PT DATA TE3:ViA ( m c-tat, FF 2 )
' - " - " ' - ' -- m -_s_ _.a ,,, ,,_m ___, _, __ _ _
s O
F L
- LOW POWERED ROD QUENCH ENVELLOPE Crt) - Ref BOCREC at 93s
-L rt.
a Y ft 3 -
+4 '-
f m - - _-
g- -
c
Q '-
w sw '
7'
,-. /
/
O i H &
m ,
X '
c 3 -
% s s
90 /
w h O Fr '
w R -
E -
=r ff!
a
[ -
? -
1 + e
/
o '
t r e /
/
O /
y a r o /
Q
@ l Q.
M cFr o C i i i i i i i g,
O l(Xi 200 20 0 =00 SV O'D 7EO X-AXIS TDE Y-AXIS Cf3 FEICMr DATA ETot I cAllLATlUI FET 2 1)
Y-AXIS ClJ PCInir DATA ETot 2 -- - - - DIGITEII) DPT DATA ED3 D-l
u m o O'l y'
.a -k 0
o W ^
Q'
~
8
$ 1 b w
' I
$ / s s
I e
' g n ' '
s.
F g b dJ / g 4
k 4 / g
/ g n
- s W ~5 o_. ' c o '
-h' C3J
_J
_J s $
W s a .
% s 8
o O s
' i I s
-k W ' ',
e '
8 '
\ -n g
a s 40069 o
ea y '
s 88 W '
W 3 '
O s B e.
- a. ' nn v 's DD 3 's CCC o '
9??
w o x m.
6 6 4 4 o
'A -
b Figure 3.1-32 CCTF Run 58, Quench Envelope - Medium-Powered Rod u A1410w-4.wpf:IMiy2844 3- 4-1
u -
\
t 4
i awy WZ>WJJ@W v[ n ' $w m8yU 0e 0n u 1
0 w-4 IH07 1o3hWo E 1 w '_.
p _k f
I b '
O <
2 9
8 F
i '
9 g /
4 u r
i e ,
3
_6 s 1
3 3 N C \
C T 6 -s F
R s' u
n g s
5 '
,8 s s
Q s s s
3 u e \
4 n 5 c r h
s E '
n v s e
l
+ s o '
p s e
- \
I '
U .
g '
h- /
s N s P
o w
e r
Ns' e
d R >c o 6, - - -- -
g k
d o 8 J k @ f>
y $W bj>C C u0 86 5 _ '
agC v0 85 m , ,
c, Rb
- b4b $~ b " ^
, , , l !1l! i1 lil1,
/
N
/
/ .
A O
\ .
3
/
& J Q /
O6
' 8 w
& s ,
L D , .
r (f) /
W / 2
& I E ?
Q. 3 E -h '
\
d w \
i
_J ,
- 0. I
/
I 1 /
w -N Q /
Q. / 1 3_5_
I dA i
,' -l 66 88
. 3% ,
b i 8
~
ac UU l
I 000 i 555 r f 9 Xh
% @ @ $ $ $ Po Figure 3.1-34 CCTF Run 58, Upper Plenum Pressure I
u:\1410w-5+pf:lt>-w2894 3 46
5 DOWNCOMER DIFFERENTIAL PRESSURE (psi)
, 1[
l V
s
!4 14-E 3 E
a w
s a-
'j n
n 10-
~
h1 Fhn-r~
F 8
- t3-f 'o o I a
b W y 8 ,I 9
a
+
e.
M 1 E
2- f
(* -- -- .
E c &
3 w
i e i e
-2 i s i i
E @ S00 E00 /w S00 0 100 200 X-AXIS TDE CALCLLATICH FTC185 SEC Y-AXIS Y-AXIS C13 C13 C CNN DATA A DATASET 01 1 2 -- -- - DIGITIZED SETO1 EXPT DATA CFIG D-37, FET >
k CORE DIFFERENTIAL PRESSURE (psi)
?
? Y"
~
r 9
'd 2
3.
E >
a
- e n
O kyy co -
(
k t-5?
S n
a y w-- --
5 a
W
-s Y $ f x-Axis me CU_ATICti FTiO4 85 E Y-AXIS ClJ C N LIVI DATA M t t Y-AXIS C13 C"N DATA M t 2 -_ _ _ . DM 1 W OPT DATA (m D, W 21)
u n
t 4
1 3G $1 Zp4hEUZh OHLkU&sUH<.
L J &&WO &w O5 0
w s
wr F
i g
k_
s u r
u
) e 9
2 3 8
9 1 4 -
3 7
C CI T h R
u n
5
,8 p
U p
e r
P l ,
3 e 6 ' '
4 n 9 u s '
\
s i, m 'I
\
t 1
N o s ,
C i
o '
n t
','i' a
i '-
n ,
m e
n t
th % % ,'
D i
f f
e r
e n
t i
a l
P r
e s
s ur o A 4 1 _ ~ ~
h k
1 h
e i 6y
- o$ Dbw 86 U,f h N c iE0 iE0 u u _
__ $9 a ' i J l lI4ll !!
n .
$ LOOP 1 - PUMP DIFFERENTIAL PRESSURE Cpsi)
{ m.
E S
f' E
s" e ra
- I&
n O
H W
'f1 lC c
D
! L i o Y -
+
$ [
E
& ~~
~~ ~- ,- s_ __
k
. . .__ __ h h
a e
Q -w
?
e _ ,,,.
O IhO 2b0 3O 50 OdO 7hD SdO
<-A<IS TDE
(-AXIS ClJ CSPJPl DATA "JETUt 1 CALCLAATICN FRCM 85 SEI; r-A*.IS C13 CtPJPt DATA *ETO 2 -- -- DLUA DPT DATA CFIG D-10 F;t7 2 >
i E LOOP 4 (BROKEN) - PUMP DIFFERENTIAL PRESSURE (psi)
. mi
- m y a 1+
O B-H m
llC 8
? w
~,
F 's
@ / .se 's --
, , ~ - ,
~
" - ~s Y A .
$ [ 4 l
\
\
g '~
" ~
! \y '
s s
c E &
R
- 9. i 2
a g w-- -
e.
B h O Ib0 2dC 3de O SED d 7de ede
<-Axis Tat Y-AXIS ClJ CfTUP4 DATA SETO) 1 CALCt.LATICN FRCM 85 E
(-AXIS C13 CFPt#P4 DATA *ET01 2 -- -- - DIGITIZED E>PT DATA CFIG C>~30, RET 2 1 >
, . .- -- . . . = . . . .
j f' u l -l 8 i l
a i
I f\i :
^ - !
M ' ,y ,
\ i i
_0 I k V T i i U !
3 -
e o i Rd J MU i i '
@d m i g ,
m i 4 i I
8
-h ), ,
O' i I
W b ,
F i 4 '
-h ,
I i O
W j
i i i
I I
O -
I :
l
__) 1 l C) i 0 - ru l 33 l 8
l
~ kh '
0.
-k &&
gg o ..
i o ' I
\
~~y --
00
= _ _ - - - - 8 22 uu i
h00 aan i
E y kk$
ek $ $ $ @ $ h f Figure 3.1-40 CCTF Run 58, Loop 1 Cold Leg Water Mass Flow I
u:\1410w-5.wpf;1b-on894 3-52 l
i d i _g i
1
^
8 n m a , -l
\ f h
.D G u $I u
3 -
o , .'
_J bv IL g i Es e 8 e ,
a 4 i-r i
s ,'
r ,' L
< s to ,
a s i e i UQ a
e ,
as '
J r s
a '
J i
_E o ,
-N I I 3_3_
- i HH o.
-$ se o -
i gg L , WEE
-g _g Das Oc UU
$00 455
)
e o AAA 6 6 6 6 6 6 e e6 6 o
, n n n n - - o Figure 3.1-41 CCTF Run 58, Loop 1 Cold Leg Steam Mass Flow un1410w-5.wpub-09n94 3-53 i
!: ' 6 y
_ t ,.
M _
_ p
~
_ >t
) 2 s T <
y
/ - N m y
b I
2 8 -
C - 1
- E W u O _ J L _
ECr p F
A NT S _ A D
S A _
M _
- N M) y g
q R - y E -
T N'mi i p A -
G L ,
W -
NID -
G -
E - -
L -
D _ - y L -
O e
C
- I2 ll
- mw g
_ q 4 xs #
w AA w
, TT w
P AA P _
DD O s L ' tMW 4 e,
- aL_
TCc r
-l I i r
R n. l-1 l fi t -
ii 8 g l i
. tl t (' o i
n g, u l: l 33 11 ,
Ct +
_ sSs -
rII
< X (,
_ xAA
/
e _ GxYy 5
0 5
+ s. e g b&
l e
w e
3 4 b 3 2 2 I i -
- ca ?5" O ,
, Ncn $ *C8O a Oo__% e kE4 gw 3CI w
SE7$*b 3~ A6" t
ll\; , 1I j) lI t(Ifl) kf
<i!l x
, - 0 0
- 0 -
\
' )
1
~
0 2
) ' ,0 -
7 F -
s E F
/
b 8 I
8 C 1
,O E W \ C E o O N C Er t
L -
SC F 3A
- UT A
S -
D -
S A
,w MT rP M
WOL M im A
E
- fp L A
L n
i
- C L T LM S - ,6 CD A G
E - -
L -
D - C -
L -
d 3 -
O C - 12 1 s
- Oui T
- E Sx 4 - ,0 0 AA 2 TT P AA DD O
O 7S fF L -
, ( Ct+ =
DLL
.DTCC
\
. l 8 iI i > i ' -
C I
l
O XYY
/
- ' e tP I
+
5iR i P*Lw OnHM 'aye = (n5 0 dh ak au @G ]. . ~ rsN 6 lf-1Il i!l1i. jl '
e l
\
_R h
n i G '
y y \ r N s .
A *
\
v '
6 s _8 3 D 3 o '
s de J 4
- u. i g3 '
m
-@ }d m '
A i ,6 3
I 4 Q' l I W _
e \ -4 i
<:1 \ _R $
3 e o ;
\
g '
W \ i J
t H 9 -8n ,
o -
T -N l '. ,.
i F 33 r SS
.a ,
a- --@ 44
- o. .
o l h "8"8 o
i bb
%_B EE
' ~ 22 UU 000 505 ,
?
o Asl 6 s 6 6 6 e o.
e6 6 - o o v n n N N -
Figure 3.1-44 CCTF Run 58, Loop 1 Hot Leg Water Mass Flow i
u:u4 tow.5.wpt: sogn94 3-56
u -
u t
o 4
J $ kr J WO (nwW $$ 1_ JO3 Oox0A w-5 p
w S8 a
s c
9 8
9 4 F i
g u
r e
3 4 1
4 5
C C
T F
R A u
n 5
,8 -
3- L -
5 o 7 p o '
1 H
o 4
_ 2 "3N [ $- 3 N/
t L
e g _ '
'i I
St 1
't '
e i',',L a i i
/
m /
j M 1 - I
- 1 a
s s -
F l
o w
o g
~
k G
$ ~
mp 4 o
E40 bW $f 140 0 n 2 hn i l O 5 E# C9 uT 8. gN0 140 0 n 2 hm l l
i l
I
% 1
- _ 3 3 ^
7n x
i S @
0 g p'
3
( -
6 o , /
3 p>mJ j
Bs i
e JL -8 (D I, 9r R hw 4 s
.g a I jo a ; i w -
H '
G
_R a 3 s
\
V o e s w s J s p \ I o 3 -$ '
T 1
-n I ' 55 T hh
- o. ,' -1 se o 88 o i J , EE
__ q g 922 nn au Dag 552
. o All 16 6 6 6 6.
6 6 6 o q n n N N - - 0 O l Figure 3.1-46 CCTF Run 58, Loop 4 Ilot Leg Water Mass Flow u A1410w-5.wpf.Itw092894 3-58 c:
. . . .i , _ . _ _ _ _ _ _ . _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ . - . _ _
i l
I l
s
,s ~{
t
\
^
\
' #d
-j'
] i h
f j
i f
/
d 3 / -h R 3
d O i Vb
_j k $6
(/) I t$
D
<[
l
-h yh u E '
E - i i-sp I I
i ?
e I '
N / ,
d i
H % ,I _g o
E Q ~
uu h00 s##
. S 6 2. o E6 + 6 Figure 3.1-47 CCTF Run 58, Loop 4 Hot Leg Steam Mass Flow uAidiow 5..pr;ib.o9:so4 g
i 4
-l 3 LOOP 4 - COLD LEG CVESSEL SIDE) FLUID TEMPERATURE (DEG F) L V E CE T ka 5
y t
{
L u
O 00 1 r O l h, m 3C c:
3 h t w .
2 \
E oco- ;
a i
< .l
'?
s -
?.
c.,
.m is - - - - - - - -- _ - _ - __ __ __
u -- -- - - - -- - - - -
n ,,
.o a ti tg 3 ' .?
E. '
m y H
o E
I g IOe , , i i i .
EE0 700 eee
." i 0 100 200 300 40 500 g "
2 X-AXIS T&E Y-AXIS CALCLt_ATDI FROM % T_C .
Y-AXISC13 C1JCLWT DATADATA SETO1SET l l
TE43CW 01 2 -.- - DIGA E>PT DATA CFIG C-24, REF 2. I) l 1 . .
i l
I 1
P
, v- -.- - _ _ . , , . e -. w- ~. , -
-w-- ,.-y4. w y w ~ .. ,. . p 3.-, _ , , . - .w. . . -a., . .4,-,.
E 7
LOOP 4 - HOT LEG FLUID TEMPERATURE (DEG F)
& ccr
~n EOF 3
V
% 9 E 3;;-
E a
& .1 e
O O
m c
M X1
- c &
2 I ,
I i g; t
. g Y I i
S I ;
u r E N
-- - - - . a-- - - - - - - --- -- - - - -- -- - - -
)O N
{
E.
a.
f E il a
n W- j g gh h 2h0 E X-AXIS TDC CALCLLAT D I N M E Y-AXIS Cl] H_4 T DATA SETO1 : O bli m W W A G C- N . U 21)
Y-AXIS C J TC6 DATA SET 01 2 -- --
, _a1- . _ .. . ,, - , , . . . .. , y _-~_. -.- - - - - - . - -e .-~.i---,-y y -,g. e,---,-- 4w e - - , . - - . - . . , , . a s ,inw, -__ _o
i E
$ LOOP 4 - LOOP SEAL FLUID TEMPERATURE (DEG F) -
? wr y i EEO- ,
n i u
5 x
C S N Y
C h
m m .
a2 ma_ a = ^ - -
a C
D 4*
~~ _ , - - - - - _ _ _ ~ '
4]D- 1 , _
m k
', ' ' ~ -
s m o , ,
- 5. \ o
- n. y H
a E 200-E 2
i? ~
3 w_
O lb N b -
x-x<Is rac
)-AXIS C13 1SWT DATA SE.Tel I CAL N TICN N 1 US SEC 4-AXIS Cl3 TE43 W DATA SET 01 2 - - - - DIGITIZED CPT DATA CFT.G Cm2@, Af7 2 1 )
i
_ . _ _ _ . _ _ _ _ ._..___._____.._m . _ , _. - . . . . . . . - . . - . . . < . ~ . . . . . . , . . - , , , . . - . . - . . -. ._____ _ _ _ _ . _ _ _ . _ . _
3.2 UPTF JV.COBRAfrRAC Validation 3.2.1 Facility Description The UFFF is a full-scale model of a PWR primary circuit built and operated by the Federal Republic of Germany Ministry for Research and Technology as part of the trilateral two-dimensional /three-dimensional research program with the United States Nuclear Regulatory Commission and the Japan Atomic Energy Research Institute. UPTF provides experimental data on multi-dimensional two-phase and single-phase flow in a PWR primary circuit.
UPTF has been designed to investigate:
. Water entrainment and separation processes in the upper plenum
. Co-current and counter-current steam water flow phenomena in the upper core tie-plate region including water break-through into the core
. Co-current and counter-current steam / water flow in the downcomer and possible bypass of the ECCS water to the broken cold leg
. Condensation and mixing processes in the hot and cold legs of the loops,in the upper plenum, and in the downcomer as a result of the injection of cold ECCS water
. Loop behavior with regard to possible water plug formation and oscillations in the hot and cold legs of the loops with ECCS injection The range of investigation is achieved by varying the configuration of the facility. Full details of the facility and its instrumentation are given in documents by R. Emmerling* and Sarkar and Liebert.*
The design of the facility is based on a 3900 MWt German PWR. There are three intact loops and a loop with a break in the cold leg. The break is represented by gate valves and orifice plates to control the flow, and a containment simulator gives the desired back pressure. The broken loop cold leg j contains a water separator whose purpose is to prevent water from entering the containment simulator.
The steam generators are simulated by four steam / water separators. On the intact loops, a feedback I
system is used to simulate reverse heat transfer in the steam generators by injecting steam at a rate equal to the water penetration rate into the steam generator simulators. Adjustable passive resistances are used to simulate the four reactor coolant pumps. The facility does not contain a heated core, but i the internals of the top quarter of the core and the upper plenum are full-scale replicas. The core itself j is simulated by a steam / water injection system to set up the appropriate flow conditions in the vessel. l A feedback system is used to inject steam into the core to simulate steam generation as ECCS water j enters the core. The steam for this purpose is supplied from the GKN power station at which UPTF is situated and is stored under saturated conditions in a storage tank at 290 psi prior to injection into the i vessel. The water injection is used to simulate water entrainment from the core due to steam upflow.
The tubes that deliver the fluid to the core come up through the lower plenum.
u:\l410w-6*pf;1tW12994 3-63 l
The reactor vessel is shown in Figure 3.2-1. De upper plenum contains 61 guide tubes, eight support columns above fuel assemblies and eight support columns outside the periphery of the core (Figure 3.2-1). De downcomer width is 9.84 in., and the vessel internal diameter is 191.7 in.
Upflow of steam and droplets through the core during reflood is simulated by injection of steam and water into dummy fuel rod assemblies. The dummy fuel rod assemblies represent the upper quarter of a core with 193 assemblies of 16 x 16 arrays of fuel rods (Figure 3.2-2). Sixty-one of the assemblies are below guide tubes and have control rod spider simulators (Figure 3.2-3). The remaining assemblies are below flow restrictors in the upper core plate. The water and steam injection nozzles are shown in Figure 3.2-4. %ere are 17 independently controlled injectors that provide a separate nozzle for each dummy fuel rod assembly.
The dummy control rods terminate at the v.It of the guide tubes (Figure 3.2-3), and the guide tubes are sealed to prevent flow from the upper plenum to the upper head. Thus, the upper head is isolated from the rest of the vessel and has no effect on the tests.
The steam generator simulators for the intact and broken loops and the broken cold leg water separator are shown in Figure 3.2-5. Flow enters an inlet plenum, which has the same volume as a PWR steam generator, and rises through cyclone tubes. The cyclones separate the water and the steam so the water can be removed from the loop. The steam flows through the steam generator upper plenum and returns to the cold leg. The steam generator simulators can inject steam to replace the liquid that is separated, but which would be boiled by reverse heat transfer in a real steam generator.
De primary coolant loops are shown in Figure 3.2-6. The cold legs have an inner diameter of 29.5 in. The ECCS injection ports are at an angle of 60 degrees to the cold leg centerline and are 19.1 ft. from the inside wall of the vessel. The hot legs have an inner diameter of 29.5 in. The ECCS injection ports are located within the hot legs and inject parallel with it towards the vessel. The nozzles are 47.2 in. from the inside wall of the vessel. Here are two downcomer injection nozzles that deliver ECCS water directly to the downcomer. Bey are located 13.8 in. above the middle of the cold leg centerline, each midway between a pair of adjacent cold legs, and have an inner diameter of 11.8 in.
A steam injection port on intact loop 2 simulates a pressurizer.
A uipped pump is simulated by an adjustable flow resistance. In the refill-reflood period of a LOCA, there is no significant positive head produced by the tripped pump, so this simple pump simulator is adequate.
The water drainage system removes the large quantities of water that accumulate during a test. In this test, water is drained from the broken cold leg water separator and the lower plenum, u:V 410w.6.upf.lb-092804 3-64
l UPTF is extensively instrumented, a full description of which can be found in 2-DB-D Program UPTF Tes Instnanentation.M The data produced from the instrumentation is continuously recorded throughout a test. This data may then be post-processed to give computed parameters. An example of a computed parameter derived from raw data is liquid level, which can be derived from the r measurement of differential pressure.
The instrumentation in specific locations of the test facility is detailed below.
He downcomer is instrumented with fluid distribution grids, turbine meters, differential and absolute pressure transducers, and fluid and wall thermocouples.
The lower plenum and core regions are instnimented with optical liquid level detectors, differential pressure transducers, and fluid and wall thermocouples.
The instrumentation in the upper plenum is summarized as follows: ,
- Wall and fluid thermocouples
- Fluid thermocouples in end boxes and below the tie-plate
- Differential pressure transducers across the tie-plate
- Differential pressure transducers and capacity liquid level detectors in the upper plenum
- Optical liquid level detectors and fluid distribution grids
- Video probes in the upper plenum
= Break-through detectors below the tie-plate
- Tie-plate drag bodies in end boxes
- Turbine meters in end boxes and in the upper plenum He remainder of the facility (intact and broken loop hot and cold legs, containment simulator and drainage vessels) is instrumented with fluid thermocouples and absolute and differential pressure transducers. ,
u N 410w-6 wpt:1b-oC844 3-65 L
3.2.2 UPTF Test 21 Description ne UPTF test 21 consisted of five runs. Two of the runs simulated ECCS delivery to the vessel via downcomer injection ports, and these have been selected for analysis. The mns are identified as ,
phase A run 272 and phase B run 274."
The test facility was cordigured for test 21 as shown in Figure 3.2-6. De steam supply used in the test was supplied from the storage tank and was injected into the system via the core simulator and steam generator simulators 1,2, and 3. He ECCS water supply was provided from the two storage tanks and was injected into the downcomer via the two injection nozzles. ECCS injection into the cold legs was not used and the intact cold legs were blocked off at the pump simulators.
He general flow of steam and ECCS water for test 21 is shown in Figures 3.2-6 and 3.2-7. The hot and cold leg break valves in loop 4 were maintained in the closed and open positions, respectively, for the duration of the test. Consequently, the flow path for the injected steam was from the steam generator simulators, along the hot legs of the intact loops to the core, where it mixed with the steam ,
injected through the core simulator nozzles, up the downcomer, and out of the broken cold leg.
De test procedure for each run was as follows. The pressure in the containment simulator was kept constant at 42.8 psi, and the lower plenum was filled with liquid at 266*F (~5*F subcooled) to a level of 2.0 ft. Steam injection to tin, core and to the steam generator simulators was initiated, and approximately 15 sec later, ECCS injection to the downcomer injection nozzles commenced.
Table 3.2-1 shows the steam and ECCS injection rates and the ECCS subcooling for the two runs. In run 272 A,2000 lb/sec of ECCS at 93.2'F was injected through each of the downcomer injection nozzles, and a total of 700 lb/sec of steam was injected via the core and steam generator simulators.
Run 274 B was divided into three subphases. Subphase I was essentially a repeat of run 272 A, but with an ECCS temperature of 257*F. Subphase II only had one downcomer injection nozzle operating l (again at ~2000 lb/sec) and was 45'F less subcooled (compared to the system pressure obtained in the l 1
test) than subphase 1. He core steam injection was reduced to 227 lb/sec and there was no steam generator injection. Subphase III was similar to subphase II, but with ECCS injection of ~2000 lb/sec into both downcomer nozzles.
3.2.3 Test Results Run 272A After the start of steam injection, the pressure in the vessel rapidly increased over the initial 17 seconds of the test from 42.8 psi to 89 psi. His pressure was subsequently reduced to ~70 psi as the ECCS flow entered the downcomer, causing significant steam condensation. He effects of condensation were reflected in the reduced steam flow entering the containment tank. De steam flow up the downcomer,2 seconds after the start of ECCS injection was, however, sufficient to cause panial ECCS water bypass to the broken cold leg and to push ECCS water into the cold legs opposite mu4 tow-63rr ;ite2 sod 3-66 j l
l the broken loop. At the same time, water penetration to the lower plenum occurred. Throughout the test, the flow characteristics in the vessel was erratic with periods of high ECCS bypass alternating with periods of increased water penetration to the lower plenum. The results indicate that increased water penetration to the lower plenum is directly related to the greater momentum of the liquid slug discharges from the intact cold legs. After 85 seconds, the water level in the lower plenum remained constant at 1.83 m. Additional water reaching the lower plenum after this time was swept up the downcomer by the counter-cunent steam flow.
Run 274 Il The subphases of run 274 B differ from run 272 A in terms of the degree of subcooling and the rates of injection flows. The degree of subcooling, which was less in all the subphases of run 274 B compared to run 272 A, had a significant effect on the flow behavior. Although the overall characteristics of the two tests (run 272 A and 274 B) were similar, the degree of subcooling in run 274 B reduced the rate of condensation and subsequently, the slug-type flow behavior in the downcomer and the plug-type flow discharge from the broken cold leg. This produced a smoother delivery of water to the lower plenum and a less erratic ECCS bypass flow. Increased water delivery to the lower plenum again corresponded to slug flow entering the downcomer from the intact cold -
legs.
3.2.4 lVCOllRAffRAC UPTF Model 3.2.4.1 Vessel Component Model Figure 3.2-8 and Figures 3.2-9 to 3.2-12 illustrate the channel arrangement in the VESSEL and show the interchannel transverse connections (gaps). The downcomer noding used for UPTF is similar to ,
that used for the AP600. [
]" The thermal capacity of the vessel and core barrel are represented by heat slabs so that the wall to fluid heat transfer can be calculated.
uA1410w-63pf Ib 002804 3-67
i i
l 3.2.4.2 One Dimensional Component Models I
i lhe intact cold legs and downcomer injection are modeled as shown in Figure 3.2-13 and j Figure 3.2-14, respectively. [ ,
f* ,
The reverse core steam flow is modeled by a mass source boundary condition in channel 9 of section 3 at the 16th axial level. This includes both the steam injected within the core and the steam injected at the three intact-loop steam generator simulators, which are not explicitly modeled.
3.2.5 Modeling of UPTF Test 21 with ECOllRATTRAC Run 272 A was run for 90 seconds of simulation time to completely cover the period of ECCS l injection. The calculation begins 31 seconds into the test which corresponds to the stan of steam injection. [
Run 274 B consists of three distinct subphases, which are modeled as two separate transients in the calculations. The first transient starts at 31 seconds (the time of steam injection initiation) and lasts for 90 seconds. There then follows a long period with no injection, which is not modeled. At 231 seconds, the steam flow resumes and marks the start of the second transient. There then follow two distinct periods of downcomer injection; in subphase II both downcomer injection nozzles are used to deliver the ECCS water, whereas in subphase 111 only one nozzle is used. The calculation models both subphases in one transient, which lasts for 175 seconds. i The boundary conditions are taken from a Quick Look Report on Test No. 21,0 ) and the calculations !
are set up in the following way. For approximately the first 15 seconds, only steam was injected via ,
the mass source boundary condition in channel 7, the steam flow being ramped in from zero to its full value over the first few seconds. Steady steam flow conditions were obtained before the ECCS flows were started; these were ramped up to their full values over 1 to 3.5 seconds, depending on the subphase of the test. The calculation was then run out for the duration of the test transient.
- 3.2.6 Calculation and Data Comparison The results of the calculations and comparisons with the experimental data are presented in Figures 3.2-16 to 3.2-39. For each run, plots are given of pressure and mass accumulation and mass flowrates w Win various pans of the system and where possible, compared with the experimental data.
The digitized plots are simple averaged representadons of the data and do not depict the fluctuations that occurred in the experimental readings. To aid the reader, each experimental plot references the ua1410w.6.wpf:1b oC894 3-68
i
- 00) This Quick Look Report presents mass balances for figure number used in the Quick Look Report .
Phases A and B. For Phase A, there is a discrepancy with up to at least 20 percent less mass measured in the system than was known to have been injected. For Phase B I, the discrepancy is up to at least 25 percent more measured mass from 70 seconds to 90 seconds and up to 25 percent less ,
measured mass after this time. The discrepancy for Phases B II and III is up to 8 percent less j measured mass in the system than thu known to have been injected. These discrepancies need to be i considered in the comparison of calculations and test results given below. In the figures and the j following discussion, all times refer to those of the experiment. l t
Phase A (Run 272) ne results for Phase A are shown in Figures 3.2-16 to 3.2-23. f t
I ne lower plenum liquid inventory is shown in Figure 3.2-16. The measured inventory shows a rise during the first 15 semids of steam injection. The Quick Look Report 00) attributes the inventory rise to the effect of dynamic pressure from the injected steam on the differential pressure instmmentation from which the liquid inventory is derived. This is not shown in the calculation. At 46 seconds, ECCS injection through the downcomer nozzles begins and by 50 seconds in the calculation, the lower ,
plenum inventory rises as two separate slugs of liquid penetrate the downcomer. At 64 seconds, a third slug ofliquid reaches the lower plenum, and the level temporarily rises again. Broughout the rest of the calculation, however, the injected steam flow from the core prevents downflow of liquid to f the lower plenum and gradually sweeps out liquid by entrainment. In the experiment, the penetration !
of liquid to the lower plenum was unsteady but much greater and continued until approximately {
80 seconds, giving a much higher lower plenum liquid inventory.
The break steam flowrates are compared in Figure 3.2-17. The calculation agrees well with the ,
experiment. Following the initiation of ECCS injection at 46 seconds, the steam flowrate reduces rapidly as a consequence of condensation of steam on the much cooler ECCS liquid. De i experimental steam flowrate remains oscillatory for the remainder of the test (although this much detail is not reflected in the digitized plots), while in the calculation, the steam flowrate remains approximately constant for the remainder of the transient, again suggesting that the calculation is underpredicting the condensation rate.
De break mixture flowrate is shown in Figure 3.2-18, while integrated flowrates are compared in Figure 3.2-19. This shows the calculation overpredicting the bypassed flow from approximately 50 to 100 seconds.
The downcomer pressure is shown in Figure 3.2-20. After the start of stetm injection to the core, the pressure increaset rapidly in both experiment and calculation. This is followed by a rapid depressurization as injected steam is condensed on the subcooled ECCS water. Throughout the transient the calculation overpredicts the downcomer pressure, although the general trend is well predicted. His suggests that WCOBRAfrRAC is underpredicting the steam condensation rate.
munomyr Iwoesu 3-69
i l
l 1
The downcomer collapsed liquid levels are compared in Figure 3.2-21. This shows the calculation underpredicting the amount ofliquid in the downcomer. In the calculation, ECCS liquid only penetrates the downcomer channels below cold leg 3 and the adjacent downcomer injection channel to any significant extent. Liquid from the other downcomer injection nozzle (adjacent to the break)is l mainly discharged directly out of the break. This behavior is similar to that which occurred in the experiment, except that in the experiment there was more liquid penetration to the lower plenum. In the calculation, the upflow of steam in the downcomer stops the ECCS liquid from penetrating a level half way down the core. Figure 3.2-22 shows the calculated average downcomer flowrate just above the bottom of the core barrel. This indicates that only three slugs of ECCS liquid enter the lower plenum.
Figure 3.2-23 shows the liquid inventories of the cold legs. The calculation predicts the cold leg 3 t
inventory reasonably well, although there are no significant liquid slug discharges. Virtually no filling of cold legs 1 and 2 is calculated, whereas in the experiment, filling these legs is similar to that of -
cold leg 3.
In summary, the calculation gives a higher break flow than that which occurred in the experiment and corresponding smaller liquid inventories in the lower plenum, downcomer, and intact cold legs. Thus, WCOBRA/ TRAC overpredicts the ECCS bypass for this test.
Phase 11 I (Run 274)
The results for Phase B 1 are shown in Figures 3.2-24 to 3.2-31.
The lower plenum liquid inventory is shown in Figure 3.2-24. As for Phase A, the experiment shows a rise in inventory before ECCS i#ction due to dynamic pressure of the steam. This is not shown in the calculation. At approximately 50 seconds, the inventories start to rise in both experiment and calculation as ECCS liquid reaches the lower plenum. The inventory in the calculation initially rises more rapidly than that in the experiment. The filling of the lower plenum in the experiment occurs over the whole of the transient, whereas the calculation shows no filling from 70 to 110 seconds (a small amount of liquid is entrained and removed from the lower plenum during this period). Overall, the predicted liquid inventory in the lower plenum is reasonable.
Figure 3.2-25 shows the steam break flowrate. The flow is well predicted before the initiation of ECCS at 46 seconds. After ECCS injection commences, the steam flowrate is underpredicted, indicating more condensation of steam in the calculation than occurred in the test.
The break mixture flowrate and integrated flowrate are shown in Figures 3.2-26 and 3.2-27. The calculation overpredicts the amount of liquid bypassing to the break,largely from 70 to 110 seconds.
Tne downcomer pressure is shown in Figure 3.2-28. The pressurization is again overpredicted, but following the ECCS injection, the calculation shows good agreement with the experiment. Neither I
umme.r t raog2s94 3-70
calculation nor experiment shows the depressurization that was observed in Phase A. His is due to ,
the much smaller subcooling in Phase B 1.
The calculated downcomer collapsed liquid level is shown in Figure 3.2-29 (no equivalent data was available for the experiment). This rises rapidly until 70 seconds, and thereafter remains roughly constant, reflecting the high bypass rate of ECCS liquid to the break during this period. De liquid mainly penetrates the downcomer by the channels below cold leg 3. The calculated downcomer flowrates (Figure 3.2-30) show constant steam upflow over the whole of the transient, and two periods of liquid downflow from 50 to 70 seconds and from 110 seconds onwards. From 70 to 110 seconds, there is a slight amount of liquid entrainment up the downcomer from the lower plenum.
Figure 3.2-31 shows the liquid inventories of the cold legs. Cold leg 3 is calculated to steadily fill with liquid throughout the transient, whereas in the experiment, the filling was more rapid. Cold legs 1 and 2 were predicted to have virtually no liquid filling, whereas in the experiment, there was some filling (and subsequent discharging) but to a lesser extent than in Phase A.
1 In summary, the calculation gives a reasonable prediction of ECCS penetration to the lower plenum and an overprediction of break flow. The overprediction of ECCS bypass for this test is not as severe as for Phase A.
Phases 11 II and III (Run 274)
The results for Phases B 11 and III are shown in Figures 3.2-32 to 3.2-39.
The lower plenum liquid inventory is shown in Figure 3.2-32. The gradual buildup of mass during Phase B 11 (while injection is from one downcomer injection nozzle only) is not predicted. The ECCS injection is only into the downcomer nozzle adjacent to the break, and all the ECCS is calculated to bypass directly out of the break. The rapid increase in mass when the other downcomer injection begins at 325 seconds (Phase B III) is more accurately predicted, but is about 50 percent too low. ,
l The break steam flowrates are compared in Figure 3.2-33. Prior to ECCS injection at 246 seconds, the flowrate is well predicted. The rapid fall in flowrate at 246 seconds due to condensation of steam on the ECCS liquid is also well predicted, although the rate for the remainder of Phase B II is generally underpredicted. We funher decrease at 325 seconds (the start of Phase B III) is also predicted, although the flowrate remains too low throughout the whole of this phase.
The break mixture flowrates and integrated flowrates are shown in Figures 3.2-34 and 3.2-35. During Phase B II, the bypass flow to the break is very well predicted, but there is a small overprediction during Phase B 111.
The downcomer pressure in Figure 3.2-36 shows a generally good agreement, with a rise in pressure prior to ECCS injection, followed by a constant pressure during Phase B 11 in both calculation and u A1410w-6.wpf.lb-oC804 3-71
1 i
experiment. A small fall in pressure when the additional downcomer injection flow of Phase B 111 is begun is followed by a pressure rise, which is also well predicted.
The calculated downcomer collapsed liquid level is shown in Figure 3.2-37 (no equivalent data was available for the experiment). This rises rapidly due to condensation of steam on liquid already in the downcomer. When the ECCS injection commences at 246 seconds, it is all initially bypassed out of the break, as indicated by the constant level. At 330 seconds, the level rises as the additional downcomer injection flow of Phase B III penetrates the downcomer. This is also shown in the downcomer flow rates in Figure 3.2-38, which indicate a large liquid downflow from 330 to 340 seconds, followed by an oscillatory period ofliquid upflow and downflow. Most of the ECCS downflow occurs in the channels below cold leg 3 and the adjacent downcomer injection nozzle.
The cold leg liquid inventories in Figure 3.2-39 show no calculation of liquid filling during Phase B II, whereas the experiment showed gradual filling of cold leg 2 and smaller filling of cold legs 1 and 3. During Phase B III, filling is predicted in all three cold legs. This reflects the filling in the experiment, although to a lesser extent.
In summary, the calculation gives a higher break flow than in the experiment and corresponding smaller inventories in the lower plenum, downcomer, and intact cold legs. ECCS bypass is overpredicted, particularly of the downcomer injection adjacent to the break.
I l
l u.u 4to. 63po n, o9n94 3-72
l Test Vessel Cover Test Vessel Flange i
' VentValve Vent Valve - - -
,-, ,, ,_, ,_. -k,[. Upper Plenum j --- Intemals
/ r NI i, l
e750 Upper Core
,1 Support Plate
- - End Box "a -
[. ~
. li fil ' . . . l' '. . .' .
0L. 4" Dummy Fuelkweminy ii ! ([u i '
& e ,4 -
M
- iJ u E M 4 11 - [,
jpg, Core S,mulator i
3 5
- - - 7 n"
. i
- d, l.d i /
, ) _m 7 -
w Zone Wall (perforated) <
, l
=
A h! l lh '"3 Nwy Core Bypass l l Structure k t e4870,
, _ w p
1 D, j j Resistance Plate
_ l r-=, -.
- p. --- ----
4 p Test Vessel (lower part)
J '= . l L f I
} .,.
1Ers!!!!! =
- s is!!!!r2ll!
=
r
=
% /
" _ m min. um. mi in unn l
l Figure 3.2-1 UPTF Test Vessel and Internals i l
u-u4 tow-64ptwocsod 3-73
I Guide Tubes
/
(' mat: g )
's- -7 Y- -
~[/ :
t i _
_i ( i j
1,
[ ] { :: ] Upper Core
. , ,, g_, Plate N
'ill M i-w JBEli'
$ T$~*MLr% '
/
'I e s . ., .-. .3
[g l _
g g y ;
- End Box 1 l P n fl u ul w
h ninusnuut i n
. dbun o
==
I il'lia ni 7 .. . '? n9,7.7 ,
su l
- s. us s, _L, ,u,s ss,)s 0000000000000003 000000000000,0000 ,c,<
s r.,- e r s e., < ', r r e f
' - ,. _, r .
. a i. , , - - - _ ,
,u v_ ALC v s ,n _ ^ im .,/v s 000C000000000000 00000000000000,00
,< sc e,e,,,e,,y y , e , e
, r. , ,
1 ch e r -
ccr e n u p_ictuce: rect:
A B injection injection Figure 3.2-2 UPTF Dummy Fuel Assembly and End Box with Flow Restrictor (A) or Spider (B) uM410w-6 mpf:ltr092894 3-74
I
_.- _. i _
q' -. .. .- . .-.
, 'p
~ ~ ~ ~~ ~
p Support Column s, y-'
i\
- Control Rod Guide Tube jj - #~
p Upper Core Support Plat.
s",
- Guide Tube Footing
--t g
. _ _4 _
. . - 2.
m_ (o L 2.a 2 2 L 2 x -
( w
~
!fif {lll.b!IibbhhlNhlb 90*
~
@l@l
-~
- . pi-g.. gW-jr- ij -
p ,q -,-
Core injection % M / #'
- 0 i l I I I II *I y '+-6 I
Zone
-f m*F --
+,,-- $ j-- - Guide Tube i
~
i, n' ifi- '[-{" n - [^ ,--
m--
I
~ln -
I
, i 4
~
fT ---"Y
^ ' -
- filfd~-
~
.. 'f([fT .JM.
LJ ,
L.!
C N. **""C'""
.T
- 6. -. .-Sn -YIi- n r.5 '
w J. _- _- - -
- w. ,
5 !@
$ _ 2 k ur Figure 3.2-3 UPTF Upper Plenum Structure uA1410w-6.wpf:lh092804 3-75 I
I l
i t w va w,1 va ,
Upper End Bon .
11 II II II II II II II IfII IIII 11 1111 tasan Spacer Grid : i
___,______.f Upper End o _. .
Active Fuel
.. g _ _
Zone Barrier sgonA en cm
,- \~ \-
N & Steam leiected into Water Line
~
t Wata o o Steam from Steam Storage Tank l
I i 1 Figure 3.2-4 UPTF Core Simulator Injection Assembly i
u \1410w-6 wpf.14002894 3-76 1
B e
i p =D k .
y lT
- 2
-/ -**==.j e1
-4 -
jJ l- -- ! b -
gb4 z.
j.I
/ Et __J-gjg ; h NE* < -
\ sr m m & .
- 1, s.
g _.s .
l 1
I E = 1 j
I g
o sU I a
- \ } .; y a.- 4
-- M
- 5 le gt=""" w A--
ssbn m_, -
^
- 3' 1Jt r- .is o a -d o / g 5
~
U '
5 1 a
- g---
D
.q.
l 4
? .
~
rr L j I o
a
~
n ]
a
= M _ _
s CN E. -ID -- >' L_ gr
=3 P--
u in g '[-
l _,
v N
[ *A }}
s-a1 j
- ---l ;
o E-l ,
Figure 3.2-5 UPTF Steam Generator Simulators and Water Separators u A1410w-6#pf 1N092894 3-77 l
t_____________________________________________________________________________________
i 5
$ Steam / Water Separator (Broken Cold Leg)
Pump-Simulator Break Valve , (Blocked)
LOOP 4 (Open)
A Steam / Water 5eparator G (Broken Loop) O O
$ 6 LOOP 1 5
'" ooO Q f ff Break Valve NB4 o o o o pyf Test Vessel Steam Generator Q
w n (Closed) ooo o Simulator Y % o o o H E I (
= --
O o O(
?
q f P cont - 2.5 Bar U _ _
I Pump-Simulator Pump-Simulator
- - - (Blocked) (Blocked)
Containment-Simulator CL -
Cold Leg HL -
Hot Leg DCl -
Downcomer injection
f P
Upper Plenn ECC Downcomer N, l Broken N Injection '
Cold Le9 ( )
4 e- s ' '
+ !
N N
i :fNN N N i N N N N N N i N ,-
g N -
k 9 Y k N , N N; N Steam Flow Down k Core And Up
] Qre ! a k i
Downcomer N i e a e N
N o a. i e i (i /
i $,,# l Legend:
Steam Flow in Core - \o a ---O Steam Flow Simu'ator injection Pipes --+ Wat e r F Low r
i I
i l
4 Figure 3.2-7 Steam and Water Injection in UPTF Test 21 u \14 tow-6*pu t,a:so4 3-79
)
l a,c Figure 3.2-8 HCOIIRAffRAC UPTF Vessel Noding - Plan View a:\l410w-6.wpf;Ib-092894 3-80
a,c i
l i
i I
L I
i 1
Figure 3.2-9 WCOBRAfrRAC UPTF Vessel Sections 1 and 2 a:u410w4.upf:lb-092894 3-81
8 a,c l
1 l
Figure 3.2-10 WCOllRA/ TRAC UPTF Vessel Sections 3 and 4 uf 1410w-6.wpf:1b-092894 3-82
l a,c i
Figure 3.2-11 WCOllRAfrRAC UPTF Vessel Sections 5 and 6 u;\1410w-6.wpf:1h002894 3-83
l l
1 a,c ;
1 l
i
'l 1
l i
1 Figure 3.2-12 WCOBRA/lRAC UPTF Vessel Sections 7 and 8 1
I l
u:u 4 to.-6.wyr ib-092894 3-84 'l l
j
a,c t
t Figure 3.2-13 WCOBRA/ TRAC UPTF Intact Loop Noding i u:\l410w-6.mpf.ItrO?2894 3 85
l l
a,c l
P I
l i
Figure 3.2-14 lVCOBRA/ TRAC UPTF Broken Loop Noding i
u:\l410w-6.upf:!b-002694 3-86 l
1
. I
1 l
a,c !
]
1 i
t I
I
)
s Figure 3.2-15 3XCOBRAfrRAC UPTF Downcomer injection Noding u u4 tow-6..pt:ite2894 3-87
C a
a LOWER PLENUM MASS INVENTORY Cib)
F Y <soce-N - - - -
g -
~~
k g m.
~ -._
= n ag;x30- s 2 Q l
/
u /
M M-m /
/
C
~4 '
H MXO- f ar$
H '
g '
w c N_- /
"U O' -
w @ '
de m 2WCO- e oo y
= l o /
5 i Scoo- i
" I m
A I m
a
' OW- -
y ,
y '
==
- 50r33-E E
o 0 E N N N3 NO N N3 d3 1dO t'e t X-AXIS TDC Y-AXIS ElJ LJT%SS DATA TTU3 I weet:ro/ t. rec Y-AXIS CIJ LJTRSS DATA ,.ETO2 2 -- -- ow i mont - clar i ved frcen di gi t i sod F"6 o 14T or CLE UPTF Test 21 Run 272 Phase A
n 5 BROKEN COLD LEG VAPOUR FLOWRATE Clb/s)
?
l Q' t t N -t
$ 21, S 5; u
- 2 w i I,J &
U /
/
h #
Q p i m
H '
3 '
n U K33- g I
w i g .
> yyy_ t g
$ \
f \
a i m
i n i i
\
Wms st Ea
.n
. , ,i w I 3 11 1 E E C v
8 E
- t h
o 30 40 50 i i 60 e
70 i
00 i
EU i
100 i
t10 12t 4 X-AXIS THE Y-AXIS C1J DCLVAFTLCM DATA SETOI 1 wckx a/t.rce Y-AXIS C1] JLCM DATA SET 04 2 -- - - - ow 6 enent - cie go t,a sed F 6 o 22 or CLR UPTF Test 21 Run 272 Phase A
s 5 BROKEN COLD LEG MIXTURE FLOWRATE Cib/s)
?
Y N e
3 3.
Iu E 2
- P ecco-E W
s en
) \,
3 R
n Y >
L N 8 i v P '
\
R-a 9
m m
?
n h 1CCO-31, R
n i::
g e
p 4 4 go -jo s k ido ito '$
M X-AXIS TDE Y- AXIS C13 DCLMDFLCM d#I*
UPTF Test 21 Run 272 Phase A
l l
l 1
E BROKEN COLD LEG INTEGRATED MIXTURE FLOWRATE Cib) f 3 4 7e y y 150000-Y ;"
l $ .
E
%XD33-C
~
?
U
=- l/ t\ /
/
i I h
! 20 COCO-i
? '
= '
ea 2 '
@ g ssxco- /
u O
O- -
c.
S CK'.033-Q 7c '
- s' S '
s'
{ 50000- ,
E -
c, C f5 e 1 a e a i
gy s 70 53 90 100 110 12
- T 40 50 CO h X-AXIS TDC Y-AXIS C13 DC1.MDFINT DATA CCTDI t webco/tr-cic y
y Y-AXIS C13 TTLOW - DATA SETEX5: 2 -- -- - w6et - d6 gt t a ced Fig 37 C2423 of CLR UPTF Test 21 Run 272 Phase A
e a
g DOWNCOMER PRESSURE (psi)
E 4
y im-3 at f
21 E 1O y
%b IJ C 120-
- u H
"r1 IN y
e _
N I h ,
~
n - %
p /', s s
- N / g
/t /s
- N
' \ g j\
I / ~,
O / # \
5 / /\ f 1 /
\ f \
5 f '
\/
\/ \ , y \/
O , ' #
/
\ /
- p. '
a '
E '
R e
b N A do ide ile ]s x-Axis rnt Y-AXIS Cl3 CCFbU DATA SETO3 vtrac Y-AXIS EtJ CCFTES DATA SETO3 2 -- -- -. .aw -t - dio. t.w ria at or as UPTF TesE 21 Run 272 Phase A
e c
g AVERAGE DOWNCOMER LIOUID LEVEL CFL) 9, Y
Iu A 4
/
i g e /
ta ' '
I.' & 1 f
ta.
t l Is C f 1 '
4
\
7 ' I Ig \
h , i ,,
e s g
@ P '
I r i I
's
- x i 1 gg N ta 1
- l I ' g s "U r\ i g
- r g
\
I \ \
N g I ,
l
- I g
\
/ \
'a
- t
,$ . 4 I
, y i
z' y i i
l /
- i
\
,l
$ 1 I
I \ l e
5 i 5
- I 'l gI - - - _ - -
' I,
= ~
i
$ p N I
$ g
% i 4
>a # \
j- l E ~
F i e i i e i i e t N 43 50 60 70 00 12 0 ICO 11O 13 Q
-- X-AXIS TPt:
Y-AXIS C13 CCLL DATA SL-'TO3 I ucobr ca/tt-ce - over o;;pe or h chemels Y-AXIS C13 IXLL-DATA SLTO4 3 - - -- - owpor- i ment - di oi t i sed F 6 g 30 of CLR UPTF Test 21 Run 272 Phase A
4 E
Ic DOWNCOMER FLOWRATES JUST ABOVE BOTTOM OF CORE BARREL C ib/s:
h 2 l # v i
~
Y l ,{ g zwo- r l 3
- C N
I- H I EU3-M _._ " f, ppy y
'lyr m. As.Wm t4 - ~-q vn v+ #W~ JJJ'd ~
d / c O, / t
~ , hj i_ - _
_ g _
D ! l
.t.o
- C tr k -1 OCO-C I j -am-Y e
E o
- 5 g -am-E R
=
-m-U o
4 h -SCCO-se W
o -tOCO-o
~
m 20 40 50 EO 70 80 90 IN 110
. i 12 h X-AXIS TRE wcct:ro/troc - overage Iimid ficwote et interfece 3 1 Y-AXIS ClJ CCLICTLCM curage entrat ned I i cm d f f cwate ot inter-fcco 3 Y-AXIS C13 CCENTFLCW - - - - wec6ccvtrce y Y-AXIS C13 CCVAPFLCW - - - Wo/troc overcs;pa vcocu- Flev ate at interfcce 3
- 1
- 2. UPTF Test 21 Run 272 Phase A 1
_ _ _ _ _ 2.__ - _ ----_-: e+-- .=ee<. e. . . -,, +e,- e.'.--S..- ,e.- = c- e+ + - * -r r-* r-*-,-r- = e-- w -
w - ..,1- . . . -%.-. . ~
i C
i a 5s INTACT COLD LEG LIQUID MASSES CIb)
-3 C UDCD-21 -_ _ .- - _.___._. ,
.- -N s
x 2 g N a e 8000-Y
'4 I Y _. N P%~\ \
ta
" "- l I N. / 9 q I / '- lA ~
q .
(
CO30- l ,
N >
\ / % '
~4 ~
a
-* SOCO-I l g /
s U l I I \ /
Y v [
o
- I
/s/l V 8 >
I I I axo-E I I i t
M g ace > I / j o
5 /
- 1 Coa-l / -
7
=
y J / m m m e m v m
=a c a Bi e- e e }{l.
__ c c c o m
5 3 5 I g g l D
I
@ SO 3
00 70 80 90 100 11O 13 y 30 2 X-AXIS TDE O WWtrce - W Cloco I >
o Y-AXIS Cl3 ICL5 LID DATA TTU2+ t M & cVtrcc - T Clocp 2)
- 3. Y-AXIS Cl3 ICLO._ID DATA. M .1 O sec&cvtrec - T Clocp 3) 3 Y-AXIS Cf3 ICL7 LIQ DATA TTU2: 1 - -O e w sment - W Cl oop I) - di gt L i sed Fi g 3 of CLR -
Y-AXIS C13 CL1t%OS DATA TTOI 3 - -M - ow t ment - T Cloco 2) - digile med Fig 24 or OJR Y-AXIS Y-AXIS C13 C13CL3F%SS CL2%SSDATA DATA TTU3 TTQ2 3 3 - '-4
- o w 6mont - T CIoop 3) - de gi t 6 eeci F6 g 23 or CLR UPTF TesE 21 Run 272 Phase A
- . . _ _ __._. _ _ . . . ..-._. _ -_ _ _ .__ _ _ . _ . ___ _ _ _ . . _ . . . _ ._ . _ . . . _ . _ _ _ ~ . - _ . _
C 5 LOWER PLENUM MASS INVENTORY.CIb)
?.
- ' aceOe-T M gm , - -
% c e A
y 293co- <
tJ is /
u '
/
7 C '
'C /
H 2C000-y _ _ _
/
d s 3
i t.a
/
W
- ? I SECO- "
Y e k -
o = ,-
I '
{ lC000-n f 9 - 'N /
2 e /
/
"3 /
= -
5
., D000-w E
n C g i i 1 5 s l
q 30 43 50 EO 70 53 90 a
1Oe 5
iIO 12 X-AXIS TIFE Y-AXIS C1] LFt%SS DATA SETO3 1 weetx ca/trec Y-AXIS C1J LFi%SS DATA SETO2 2 -- - - - ow 6 mont. ~ char- 6 ved Orcm cf e o6 t. 6 sed Pi D 1Sr or Q.R UPTF Test 21 Run 274 Phase BI
C l r
j BROKEN COLD LEG VAPOUR FLOWRATE Cib/s)
- L s
- at g Q 12C0- ,.
2 5 ,'
? sa
,a ,
/
t2 tn /
I CCO- '
~ _ __
O t
/
/
d /
$ W ,
/
T /
- r '
M
<a '_ Cm- . _ -
t Q
- ,' I
/
J ." /
- g X /
1 I
f 1
k 7: cw i n i B
i i i i i ~t 3 i 50 i
W i
70 00 90 1CO 110 I22 o N 40 4 x-AXIS THE Y-AXIS C1] SCLVNYLCW DATA 2 1-I wotro/tr ce Y-AXIS Cl3 S LCW DATA D O4 2 -- - - O w ltnant. - di gi l. 6 sed f a g 33 of CLR UPTF Test 21 Run 274 Phase BI l
l l
i 6 BROKEN COLD LEG MIXTURE FLOWRATE Cib/s)
?
9
~0 M C 3
% 5 5 3 2 w U.' '
w e
C m
H m
H b
u m 3 .
l u
a 1
w =
h oo y
k 'N E-a n
SL CL im V
T.
!1 e
A E o-
=
I I I I I I so g I ee i
o 30 e T OO 70 ieo iio i 25
{ X-AXIS TIFE Y-AXIS ClJ DCLMDTLCM u ctr o/tr cr:
UPTF Test 21 Run 274 Phase BI
= _ . _ _ - _ .
e C
i9 m.
?
BROKEN COLD LEG INTEGRATED MIXTURE FLOWRATE Clb) i ;
iF P' E00CO-
'4 3 ,
5 U u
C m
& 25CCCD- '
M H
Dl n
t_a
- 200 0'13-6 /
m i M I y ,
m 1 EO3CO- 's f Y' 3 / ',
8 7 C
/
/
O e -
1C0000-E ,-
~
n
[ "
m /
c '
X '
n meco- -
3 '
E '
o y s' E' -
E O'
- i
. . i i i E ao e i
m w 7e m 90 ico iso h X-AXIS TDf_
Y-AXIS C13 f3CtJtDf DE DATA:23BI I metro /tro:
DATA M . 2 - - ow e ment - di gi li saad Fi g 39 C20256 of C1 Y-AXIS Cl3 TFLOW f
UPTF Test 21 Run 274 Phase BI
- - - . . LI
n 5 DOWNCOMER PRESSURE Cpsi)
?
y 1&
9 I
n 3
+-
9 fCO-s' '
__ _ ~ _ _ _ _ _ _
G -
e '
y _-
, 1 43- ,
oc -
/
C '
- Q '
H m t 29--
H '
3
~ /
tJ W w /
b T I@ /
8 =
$ /
G /
J po- ,-
C o /
$ /
o o
/
E" CO-
/
a '
E
- e ~
, , . . . , , . i 30 43 50 CO 70 80 GO t00 110 122 x-AXIS THE Y-AXIS C13 CCFFES DATA TTD3 1 weetrortroc Y-AXIS C13 DCFFES DATA SCT03 2 -- -- o w ernent - di gi t e cod F a g 32 of O.R UPTF Test 21 Run 274 Phase BI
b AVERAGE DOWNCOMER LIQUID LEVEL CfE) 7 s'
x d- 4.s-5 4 a
- w t,4 4.O-O
@ s s-H m
H 3 0-Q m 2 s-
=
8:
a w
S .- e o-o ;
i g i s_
s 4
o i&
Er
? O s-2l, r
EC E O O-
~
?
- 4 s s "
eo m iie 1 I'O la e
i x-axrs rac Y-AXIS ti3 g # "OC - N oge of h y g UPTF Test 21 Run 274 Phase BI
i e
e 2
g DOWNCOMER FLOWRATES JUST ABOVE BOTTOM OF CORE BARREL C I b/s: I I m 1 5-y ,~ a.n- q..r s.~.g ,,- ,/ ~-- ^ ~ ^ s < - s v ~ y
/ I u P / ) t S * / It g1 s\ t- l
$ E j
- 8 _#
4;fg
~
~ ' f t.'g _
b- !
p* ~ I , I i I
o 't ?. I 2He5
==J h
I y if I p, i I t' r
, g I IJ l 8
[a g
- g 1 i nly
-8 i
II I k *g'
- II ig
-1000- t s ,th w~
g 8
lI tt }
i 3
k.
Y W 2; r -2000- >
ea C
n 5
3 o
5
, m-n d
a 3e 4
6 g -- <1C00-
, . . . . i
[
e 'JO 43 50 EO 70 00 90 100 110 13
$ X-AXIS TIFE i
- Y-AXIS Ei3 CCLITLOW wcc4:r-o/troc - over ogo I 6 cuid fIcu oto at intorfoco 3 tc Y-AXIS EI3 CCENTFLOW - - - - - ucot:r-Wtroc overcoo entroined I e cui d fIcu ote ot. Int.or-roco 3 C. Y-AXIS El] CCVNTLOW - - - - wcobrdtr'oc - overogo vcocu- fleu oto el interfoco 3 ;
I e
i 9 UPTF Test 21 Run 274 Phase BI -
l A i
..,- - - - ..-e--a-. . .+.---..ev- ----,.-.-i-4,e--.e --..e.- ..---.,s. - , - - . . * + -w--- w <-- ve .v- m-- --eww--- ,-~--en r- ,v"<-+< - -1 w -w = .-w--e--+---~w.*-cu c--e. v e,. . , , . - - ,, -.,. . . -.. _
5 INTACT COLD LEG LIQUID MASSES (Ib) 6 f
ss Y Y ~ -- ~ _ _
$q m -- ._ __ _ ,
g /
i'i =
2 , w
/
1 Y /
u
" ODCD- /
C /
m M. /
m m
/ /
y I xt U 4Xo- I /g 3
7 w I 3 75}-
l II\ s
/ '
L o
w ,
- 1I '\ '
W II \ /
ii lI \ s/
x-- - -- - - _ - _ - ~ - - - - _ _ ~
2 gj m ,.
E M
II 0 - -- - - - - - - - - - - - - - - {
7 5 5 3 3 m
-j _
-j 0- C 9 .,
= e . . . i i i CD 70 00 50 100 110 1Et 30 @ GD 3
d x-AXIS TPE O uccbecv'troc - t41 Clocp t) 5 Y-AXIS Cl3 ICL9_IO DATA SETO2 t "
hev'trce - FC Clocp 2)
- Y-AXIS CI] ICLCLlD DATA SETI%2
- 1 O weebece'trcc - SE C l oco 3)
E' Y-AXIS Cl3 ICL7LIU DATA SETU2- t - -O - ow 6 mont - FM C l oco 1 ) - di gi L i sed Fi g 32 of CIR Y-AXIS Cl3 CLit%SS DATA SCt01 4 - ow i ment - FE Cloco 2) - digittged Feg 32 or cgp Y-AXIS El3 Q_ZP%SS DATA N 3 --4 - ow s ment *C Cloco 3) - di gi t e cod Fi g 32 or CLR Y-AXIS C1] CLT%SS D/6fA SETm 3 UPTF Test 21 Run 274 Phase BI
s a
t F
LOWER PLENUM MASS INVENTORY Clb) 4 C h I
? R 5
- arxo- '
6 P
es f
'e !
I C
% I 47XO- I i g ta 3 a5xO-g ',.
g '
y - __ __
=_
S
- R*
y mm-t*
C m 1OCOO-E e
3 Bi m
em
~
E C i i i i i i i i i
$ 220 2@ 250 200 3CO 320 3 43 3EO 300 4%) l E X-AXIS T&E Q Y-AXIS Cl3 IJT%SS DATA EETU3 1 wect:r evtr o:
Y-AXIS Et3 Lft%SS DATA SETO2 2 -- -- ow4et - eke i ved fr cm d: o s t i sed f i g 15f of CLR UPTF Test 21 Run 274 Phases B II & III
i g BROKEN COLD LEG VAPOUR FLOWRATE Cib/s)
O
-1
?e 3Co-g _.----g g ,
\
8 P N
/ /
l /
2D /
' \ /
c 1 1 t
' \ /
7 H I / \ '
9 / 1 /
\ '
w l
\ ' l b 200- , g I l
8 i f 3 i 3 I g /
/
N g i
---,/
g g g
f v = I y \ l
" i d I 8
E I g 8
' i /
\ -
m g ' hl 1 \
\}
i / T
- r a , i' '
' ( , e p ' > \
s
- i i
h I n
W B
g C 5 . . . . i . . . .-
243 2EO 200 3C0 - 320 343 300 300 400
@ 220 X-AXIS THE D Y-AXIS Cl3 EKI.VNT1_OW DATA M1 I w c4:r e tr c e
- di gi t i sed F 6 g 33 of CtJR i j Y-AXIS C13 9 l_OW DATA- JETD4 2 - - - - - ow t onant.
i UPTF Test 21 Run 274 Phases B II & III
E y BROKEN COLD LEG MIXTURE FLOWRATE Clb/s) e 2 3 $ N I,
P,,
E 'k C
I a'
H
$ SECO-d 3 l n ~ \ 8
- (!
i E N v -
/ ll >
X b '
(
5 m .
3
,.=
n i E
O k
1000-EM e
v h 220 2b 2dC 2b 3dO 3dD 3b 3dO 3de b
- D x-AXIS TIFC o Y-AXIS C13 CCL.11DfLCM weetr cn/tr cs:
- l!
UPTF Test 21 Run 274 Phases B II & III
.E.
B BROKEN COLD LEG INTEGRATED MIXTURE FLOWRATE (ib) f r$ M~
- c. c
.I. m
/
{ i;a 4C0C00-U g e. 3secco-e gN
,, H 9 -
hH 3Ecoco- -
=a '
RJ N 25EO30- ,'
- r 5 s' w ,'
J e rocctm-O O n
= 150C00- ,.'
t,t
$ 1 COCUF B -
O ,'
k Scoco--
r
'\
- _L 7
~
kg 220 i
29 2EO s
200 a
300 e
320 i
343 3EO 380 i i 400 E X-AXIS THE C= Y-AXIS C1] LY11tDf'D4T: DATA- SCTO1 - 1 weetr-dtr oc
- g Y-AXIS C13 in'l C41 DATA SETOG 2 - - - - - e>g>en e e t - de ye t i sod F e g 39 C2025+C2032 of CL p-e a
UPTF TesE 21 Run 274 Phases B II & III
s
-h t
\
\
<~
[
H i uo H 1
s h
-h ?H s L H C s O
G 5
- 0. g U [ -k } O W
/ )0 r D ,'
8 $
@ .? h W \
i h %pw W
[ i
\N V
i o C
E \
3 W
i
-g i O' E \
i i N i
3 e O 1
-N o 88 -
i i
EN u_
i n sw 2a r O_
x
-B 88 D
~ )%
~- b) hk s
s ~k CD uu
+,
g Aw$
g h g V' o h Figure 3 -36 1]PTF Test 21 Phases B 11 & 111' Downcomer Pressure ggw .twpt:1M*:8" 3-108
R fm AVERAGE DOWNCOMER LIOUID LEVEL CFE) d E
54 7
- g u S-
\
f If l l
^
d t
'~ )
Q E f m
H w
==.
W E
a c:
'? C
- +
8 *
=
n c
2 4 2-9
'S t-8.
C
.c ~
c i i i a EC C . . i e i 320 340 3CO 380 4'O E 240 260 200 3C0
$ X-AXIS TDC
- 2. Y-AXIS C13 CQL uccbecu'trce - overcy of h chcrret e UPTF Test 21 Run 274 Phases B II & III
e
@ DOWNCOMER FLOWRATES JUST ABOVE BOTTOM OF CORE BARREL C I b/s:
Y m 3 g asoco-I a
?> w
? I.'
's 2 Coco-
=c
.N i e 1*3000-B e -4 "3
. n~
%M o
10000-
=N c: 7 5N y 2. 3 seco_
C =
0 O
- 04, h
C f~fnl } .
s -seco-e a
g -icoco-N m -
3 I I I I 4 5 220 I
243 I
2EO 200 3EX3 320 3 43 3E0 300 @
g X-AXIS THE pw Y-AXIS C13 [XLICFLCM Y-AXIS C13 CQNTTLCM - -
ucetro/troc - overage 16cuid ficw olo ot interface 3
- weebro/tece - average entroinoci f icuid ricwote at int.orfcco 2
" Y-AXIS C1] CCVNTLCM - - - do/trec - overage vepcu- riewote at inter-reco 3 cr a
n UPTF Test 21 Run 274 Phases B II & III
_, _ . , - . , - . s s - o e-e-, + -e, ,-w ,t---,-- - - - , + _ _ _ - _ - _ . _ _ _ _ _ . _ _ . _ . _ _ _ _ _ . ~ - _ _ _ . - . _ . - .__. ~.-.
E e INTACT COLD LEG LIQUID MASSES (16)
?9 E 21
% n E
-k
. a l E
is 0 l
- p k N ,
tKAW [
b
- Y I
.\
g '
/
~
N N ta f N
~
~
I N. / X g 4D00- x y Ig l; m /k -
v
_ _ e
~ s E li l V l
/
.A
~
l
- 'M . - -M-~ ~ -~ /
Er i !
V--
G I I - ~
5 Iw j
/
o_
y& . -== ;- : c . _ ~~ ~_. ~
ya D-
- _ 7_ _ _ _
y 220 2b 2$0 2b0 3$0 320 3b 3de . 3$0 E
- X-AXIS T&E O wocbe d troc - fW Cloop 1) l 3 Y-AXIS Cl3 Tn RTn DATA- TTEK2: I M ucetr ca/troc - K Cloco 2) e Y-AXIS Cl3 ICLCLIQ DATA-SETEE23 : 0 WWt. roc - - TW CCIoco 3)
E Y-AXIS C13 ITL71._IQ DATA:m- t w l et. l ocp I > - d 6 gi t. i med Fi g 32 or CLR C Y-AXIS CIJ CLt t@SS; DATA
- M1 :3 - --O U- Y-AXIS Cl3 CL2 MASS DATA M:3 -- 4 'ow- let - ow -i fC mt C
- lToco Cloco 2) -3)di-g6 di Lgi i sed t6 eed F 6Fgig 3232ofof CLR CW E Y-AXIS Cl3 CL3%SS DATA TTU3:3 I
UPTF Test 21 Run 274 Phases B II & III ,.
i y-,----J 'm3-
,- v v- --
W v wt P f-- wf T- e---ar. s ee 't _ _ - _ _ _ _ _ - . - -.____------.__.___m-__m.-
l l
l 3.3 Conclusions l
WCOBRA/ TRAC calculations of CCTF run 58 and UPTF test 21 runs 272 phase A and 274 phase B have been performed to provide code validation for large-break LOCA applications for the AP600 l plant. The CCTF and UPTF tests have downcomer ECCS injection representative of that of the AP600.
The calculation results of CCTF run 58 showed reasonable agreement with the thermal-hydraulic j behavior of the test. Peak clad temperatures were generally overcalculated compared to those of the test, particularly for the hot rod and at upper locations.
i The calculation results of the UPTF tests showed an overprediction of the liquid discharged from the l break (bypass) and an underprediction of the injected liquid entering the lower plenum. ,
I The overall conclusion is that WCOBRA/ TRAC has been shown to be valid for calculating the thermal-hydraulic behavior associated with downcomer injection during a large-break LOCA.
WCOBRA/ TRAC overpredicts the liquid discharge from a cold leg break, (bypass), and thereby underpredicts the rate of filling of the lower plenum by the downcomer injection water, resulting in an overprediction of the peak clad temperature.
u A1410w-7.wpf:1t>&>2804 3-112
i 4.0 APPLICATION OF THE ECOBRA/ TRAC CODE UNCERTAINTY TO THE AP600 Introduction The best-estimate methodology used for the large-break calculations was to use a "superbounded" plant calculation as the basis to determine the peak cladding temperature (PCT). Plant conditions were chosen in a conservative manner to bound the uncertainties in these parameters. The remaining uncertainty that must be accounted for is the uncertainty in the calculational method or code, in the original SSAR calculation,0) the WCOBRA/ TRAC-Mod 4 code uncertainty developed for the two-loop plants was used as the basis for the code uncertainty to be applied to the AP600. At that time, the most recent WCOBRA/ TRAC uncertainty from Addendum 3 to WCAP-10924 was applied to the AP600 large-break analysis."O Also, an additional uncertainty of 50*F was added to the calculated code uncertainty for the AP600 to retain additional conservatism in the reported AP600 large-break LOCA PCT results.
With the issuance of the WCOBRA/ TRAC Code Qualifying Document (CQD),(3) the code uncertainty has been recalculated for the WCOBRA/ TRAC code with an extended data base that is applicable to the AP600 large-break LOCA. Therefore, the code uncertainty derived in the WCOBRA/TP AC CQD will be used as the basis for the code uncertainty that will be applied to the AP600 large-break LOCA calculation.
4.1 Application of the CQD Uncertsinty to the AP600 Large-Break LOCA Calculation The details of the calculational method to dedve the WCOBRA/ TRAC code uncertainty are given in Section 19 of the CQD for WCOBRA/ TRAC, and only the results and the application of the results for the AP600 large-break LOCA analysis will be given in this report.
The calculated code uncertainty consists [
]
I
] 'Ihe experiments that were used to derive the code uncertainty for each PCT are shown in [ ], which was taken from the WCOBRA/ TRAC CQD. Since the large-break LOCA transient for the AP600 is essentially the same as that for a three- or four-loop PWR, the same data can be used to develop the code uncertainty for the AP600.
uM410w Empt:ltwo92894 4-1
I
[
I l
i 6
6 03 ]* Figure 4.1-1 shows graphically, how the uncertainties can affect the code comparisons to the data for the reflood peak.
The spread of the different test data for each test or data set can be seen in Figure 4.1-1, [ ;
ja.c The final numerical values for the WCOBRA/ TRAC code uncertainty for each PCT at different elevations are suminarized in Tables 4.12 and 4.1-3.
I FCT 33P' Figures 4.1-2 and 4.1-3 show the calculated values of the code bias and total uncertainty plotted as a function of elevation. [
ja.c i
The PWR PCT can occur at any elevation, but particularly between the core mid-plane,6-ft., and 10-ft. elevations depending on the axial power shape, design of the reactor vessel internals, and the
. \
u:\1410w 8.wpf;1b-W2894 4-2 I
l
9 emergency core cooling system (ECCS). [
ja.c The above average values for the code uncertainty are shown on Figures 4.1-2 and 4.1-3.
i 1
uA1410w-8 mpf;1b-M2894 4-3
- a,C TAllLE 4.1-1 TEST GROUPING l'OR DIITERENT PEAK CLADDING TEMPERATURES 4
TAllLE 4.12 CALCULATION Ol' WCOllRAffRAC CODE UNCERTAINTY - IILOWDOWN PCT t_
u 11410e 8 wpf:lMN2W4 4-4
- a,c TABLE 4.1-3 CALCULATION OF WCOBRA/ FRAC CODE UNCERTAINTY - REFLOOD PCT u:\1410w4 wpf.lb-(N2994 4-5
a,c l
1 l
4 Figure 4.1-1 Components of WCOllRAfrRAC Code Uncertainty for Reflood PCT at 6-ft.
Elevation l 1
u A1410w-s+pt:Ib-on894 4-6 ;
a,c t
P' Figure 4.1-2 Average Code Bias and Uncertainty for Blowdown u:\l410w-8.wpf 1t>-092894 4-7
a,c l.
I l
l I
Figure 4.1-3 Average Code Ilias and Uncertainty for Reflood '
l u:\1410w-8.upf.lb4W2804 4-8 I
l l
4.2 AP600 Large-Ilreak LOCA 95th Percentile PCT )
l The results of the large-break spectrum are given in Table 4.2-1, which is the same as Table 15.6.5-7 in the AP600 SSAR. The blowdown and reflood peak cladding temperatures (PCTs), as given in the tahic, indicate that the Co = 0.8 case is the most limiting since the other cases quench during the blowdown phase of the transient. Note, as mentioned earlier in Section 2.0 of this report, that large- l break LOCA calculations that have been performed since the SSAR calculations are also indicating that the hot rod will quench during blowdown even for the Cp = 0.8 case, such that the SSAR case is most limiting.
[
]^ To calculate the 95th percentile PCT, the code uncertainty values from Equations 4-2 and 4-3 will be used with the Co = 0.8 case from the SSAR.
[
9 uM 410w-ftwpf ltWN2894 49
1 l
3a.C (4-8)
This value included an additional 50*F, which was added specifically to be conservative for the AP600. [
i ja.c f
I u A1410w-8mpf.ItW12894 4-10
)
TAllLE 4.2-1 AP600 SSAR LARGE-BREAK LOCA BREAK SPECTRUM PEAK CLADDING TEMPERATURE (PCT) RESULTS lilowdown Phase Reflood Phase Time of Reflood Case PCT PCT PCT, Elevation Cp= 0.8 DECLG 1472*F 1565 F 102 sec. at 8.0 ft.
Co= 1.0 DECLG 1399"F non-limiting due to rod quench Cp= 1.0 CLS 1226 F non limiting due to rod quench Cp = L2 CLS 1428'F non-limiting due to rod quench Cp= 1.0 DEHLG 711*F at the initiation of blowdown The DECLG is the double-ended cold leg guillotine break Tbc CLS is the cold leg split break The DEHLG is the double-ended bot leg guillodne break u \1410w-8xpf.lb-092894 4-1]
-l l
t
! l l
1
5.0 CONCLUSION
S Re processes and thermal-hydraulic phenomena for AP600 large-break LOCA have been compared to existing three- and four-loop PWR large-break LOCAs and have been found to be very similar, if not identical,in most cases. He PIRT charts for the AP600 and an existing PWR were almost identical. )
ne new passive safety features of the AP600 design, such as the core makeup tanks and ADS, play j almost no role in the large-break LOCA transient, and the peak cladding temperature is terminated by the flow from the accumulators. The injecdon location for the passive emergency core cooling systems is different from the current Westinghouse plants. The injection location for the AP600 is into the reactor vessel downcomer, rather than the reactor cold legs. Since the injection is into the reactor vessel, both accumulators, which are larger than existing PW'Rs, are available to provide core cooling, which results in terminating the calculated peak cladding temperatures at low values.
He ability of the WCOBRA/ TRAC code to predict the thermal-hydraulic behavior for direct vessel injection was examined by comparing the WCOBRA/ TRAC code predictions to the Japonese cylindrical test facility results (CCTF) for an experiment with direct vessel injection and comparing WCOBRA/ TRAC calculations to the full-scale upper plenum test facility (UPTF) experiments with direct vessel injection. The comparison of the calculations to the test data indicate that the WCOBRA/ TRAC code can predict the thermal-hydraulic behavior for the direct vessel injection i design, lending credibility to the resulting AP600 plant calculations.
l The final calculated peak cladding temperature was calculated using the more recent WCOBRA/ TRAC code uncertainty developed in the Code Qualifying Document for WCOBRA/ TRAC. De revised uncertainty calculation resulted in a reduced 95th percentile peak cladding temperature as compared to the original calculation provided in the SSAR. The resulting 95th percentile calculation was significantly below the licensing limit of 2200 F, so that ample large-break LOCA margin exists for the AP600 plant.
l l
l l
]
l i
1 1
l uA1410w-8 wpf.ItMN2894 5-1 j l
l I
6.0 REFERENCES
- 1. Kemper, R. M., J. S. Petzold, and L. E. Hochreiter, Application of the WCOBRA/ TRAC Best '
Estimate UPI Model to the Haddam Neck PWR with Zircaloy Fuel, WCAP-12766, November 1990.
- 2. Guidotti, T. E., and M. J. Thurgood, A COBRA / TRAC, Best Estimate Analysis of a IArge Break ;
Accident in a PWR Equipped with Upper Head Injection, NUREG-CR-3642, March 1984. l Bajorek, S. M., S. K. Chow, L. E. Hochreiter, S. B. Ngayen, M. E. Nissely, K. Ohkawa, and !
3.
M. Y. Yaung, Code Qualification Documentfor Best Estimate LOCA Analysis Volume IV and V, WCAP-12945-P, June 1993.
- 4. Wilson, G., et al., Quantifying Reactor Safety Margins, NUREG-CR-5249, December 1989.
- 5. Westinghouse Electric Corporation, Simphfied Passive Advanced Light Water Reactor Plant Program, AP600 Standard Safety Analysis Report, DE-AC03-90SF18495, June 26,1992.
- 6. Dederer, S. I., L. E. Hochreiter, W. R. Schwartz, D. L. Stucker, C. K. Tsai, and M. Y. Young, Westinghouse Large-Break Best Estimate Methodology Volume 1 and Volume 2, Application to Two-Loop PWRs equipped with Upper Head Injection, WCAP-10924-P-A, December 1988.
- 7. Sugimotgo, J., et al., Data Report on Isrge Scale Reflood Test -78, CCTF Core-II Test C2-AA2 ;
(Run 058), JAERI-memo 59-446, February 1985.
- 8. Emmerling, R., et al., UPTF: Program and System Description, Siemens U9 414I88/023, November 1988.
i
- 9. Sarkar and Liebert,2-DB-D Program UPTF Test Instrumentation, KWU R515/85/23, September 1985.
- 10. Quick Look Report Test No. 21 Downcomer injection Test, E314/90/16, September 1990.
- 11. Hochreiter, L. E., C. K. Tsai, S. M. Bajorek, H. C. Yeh, K. Takeuchi, T. S. Andreycheck, and R. D. Ankney, Westinghouse Large Break LOCA Best Estimate Methodology, Volume 2, Addendum 3, Upper Plenum injection ModelImprovement, WCAP-10924, Revision 2, Addendum 3, April 1991.
u A1410w-E wpf:lt4N2894 6-1