NUREG/IA-0207 

International 

Agreement Report 

RELAP5/MOD3.2.2 Gamma Assessment 

For Down To Top Reflooding Process 

At VVER Like 37-Rod Bundle 

Prepared by: 

A.S. Devkin 

Russian Research Center *Kurchatov Institute" 

Kurchatov Square I 

123182, Mosco,', Russia 

Office of Nuclear Regulatory Research 

U.S. Nuclear Regulatory Commission 

Washington, DC 20555-0001 

July 2002 

Prepared as part of 

The Acreement on Research Participation and Technical Exchange 

under the International Code Application and Maintenance Program (CAMP) 

Published by 

U.S. Nuclear Regulatory Commission
I L_

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I
NUREG/IA-0207

International 

Agreement Report

RELAP5/MOD3.2.2 Gamma Assessment 

For Down To Top Reflooding Process 

At VVER Like 37-Rod Bundle 

Prepared by: 

A.S. Devkin 

Russian Research Center "Kurchatov Institute" 

Kurchatov Square 1 

123182, Moscow, Russia

Office of Nuclear Regulatory Research 

U.S. Nuclear Regulatory Commission 

Washington, DC 20555-0001 

July 2002 

Prepared as part of 

The Agreement on Research Participation and Technical Exchange 

under the International Code Application and Maintenante Program (CAMP)

Published by 

U.S. Nuclear Regulatory Commission
CONTENTS 

LIST OF FIGURES 

ABSTRACT III 

EXECUTIVE SUMMARY IV 

INTRODUCTION 1 

2. TEST FACILITY DESCRIPTION 1 

2.1 Circulation loop 1 

2.2 Test section 1 

2.3 Rod bundle 2 

2.4 Measurement system 3 

2.5 Test procedure 3 

3. TEST SCENARIO AND INITIAL CONDITIONS 3 

3.1 Test scenario 3 

3.2 Starting values of main parameters 4 

4. NODALIZATION SCHEME DESCRIPTION 4 

5. RESULTS OF CALCULATIONS 4 

6. SENSITIVITY ANALYSIS 17 

6.1. Radiation heat transfer influence 17 

6.2 Axial power distribution influence. 19 

6.3 Radial power distribution influence 21 

7. RUN STATISTICS 29 

8. CONCLUSIONS 31 

REFERENCES 32 

Appendix A. TEST FACILITY SCHEMES. 33 

Appendix B. INPUT DECK FOR BASE CASE 46

i
LIST OF FIGURES 

Fig. I N odalization schem e of test section ....................................................................................... 5 Fig. 2 Rods cladding temperature behavior at H=I. Base case calculation and experimental data .......... 6 Fig. 3 Rods cladding temperature behavior at H=2. Base case calculation and experimental data .......... 6 Fig. 4 Rods cladding temperature behavior at H=3. Base case calculation and experimental data .......... 7 Fig. 5 Rods cladding temperature behavior at H=4. Base case calculation and experimental data .......... 8 Fig. 6 Rods cladding temperature behavior at H=5. Base case calculation and experimental data .......... 9 Fig. 7 Rods cladding temperature behavior at H=6. Base case calculation and experimental data ........ 10 Fig. 8 Cladding temperature of rod N19. Base case calculation and experimental data ....................... 11 Fig. 9 Cladding temperature of rod N22. Base case calculation and experimental data .................. 12 Fig. 10 Cladding temperature of rod N27. Base case calculation and experimental data ................ 13 Fig. I I Full pressure drop at heated zone ....................................................................................... 14 Fig. 12 Pressure drop at upper part of the bundle ............................................................................ 15 Fig. 13 Pressure drop at lower part of the bundle ........................................................................... 16 Fig. 14. Quenching front position. Base case and experimental data ............................................. 17 Fig. 15. Radiation heat transfer between rod bundle and vessel wall influence for H=5 .................. 18 Fig. 16. Radiation heat transfer between rod bundle and vessel wall influence for H=6 .................. 19 Fig. 17. Axial distribution influence on cladding temperature behavior for H=4 ................ 0 Fig. 18. Axial distribution influence on cladding temperature behavior for H=6 ............................ 21 Fig. 19. Rod of type "B" temperature behavior. Experimental data for H=4 .................................. 22 Fig. 20. Rod of type "B" temperature behavior. Experimental and calculated data for H=6 ........ 23 Fig. 21. Rod of type "A" temperature behavior. Experimental and calculated data for H=6 ........ 24 Fig. 22. Rod of type "B" temperature behavior. Experimental and calculated data for H=5 ........ 25 Fig. 23. Rod of type "B" temperature behavior. Experimental and calculated data for H=4 ........ 26 Fig. 24. Quenching front position. Two-channel model results and experimental data ................... 27 Fig. 25. Pressure drop at the heated zone. Experimental data and results of calculations with two

channel schem e ................................................................................. 28 Fig. 26. Pressure drop at lower part of heated zone. Experimental data and results of calculations with 

tw o -ch an nel schem e .................................................................................................................... 29 Fig. 27 CPU time during the test calculation. ......................................... 30 Fig. 28 Tim e step behavior during the test ....................................................................................... Fig. 31 IA. Loop scheme................... Fig.~~~ ~ o p ~ ~ sh ~ IA m .......................................................................................................... . . . . . . . . . . . . . . . . . . . . .3 33 F ig . 2A . T est section schem e ............................................................................................................. 34 Fig 3A. Upper plenum with current lead plate (1) and perforated plate (2) .................................... 35 Fig. 4A. Rod imitator with indirect heating. 1, 8 - copper rods, 2 - thermocouples, 3 - cladding, 4 

NI, Cr heater, 5 - pinch barrel, 6 - pulling wire, 7 - MgO, 8 - 9 - cone current lead ............... 36 Fig. 5A. Axial power profile and thermocouple arrangement along the height for the test section KB

37 .1 ................................................................................................................ 3 7 Fig 6A. Transducer arrangement (a) and the power profile map (b) across the test section KB-37.1 (top 

v ie w ) ........................................................................................................................................... 3 8 Fig. 7A . Instrumentation for the test section KB-37.1 .................................................................... 39 Fig 8A. M ain parameters behavior during the experiment ............................................................ 40 T a b le A -I ........................................................................................................................................... 4 1 T a b le A -2 ........................................................................................................................................... 4 3 T ab le A -3 ....... :... ............................................................................................................................... 4 5

ii
ABSTRACT

The assessment of RELAP5/MOD3.2.2 Gamma for down to top reflooding at VVER like 37-rod 

bundle is presented. The experiment have been performed at IPPE test facility at the following 

parameters: upper plenum pressure- 0,246 MPa, cooling water temperature- 51 'C, water velocity- 4.91 

sm/s, average linear heat flux density at maximal heat production zone before water supply-1,77 

kWt/m. RELAP5/MOD3.2.2Gamma assessment showed that code gives satisfactory results for all 

parameters behavior. The main discrepancies were get for cladding temperature behavior at level H

2.7m, where the calculated cladding temperatures exceed experimental data approximately on 75 K. 

Computed quenching time for this level are much higher experimental ones. For other levels 

accordance between experimental and RELAP data is rather good.

iii
EXECUTIVE SUMMARY 

This report presents the of RELAP5/MOD3.2.2 Gamma assessment in the prediction of reflooding process in VVER like 37-rod assembly with bottom to top water supply. The results of base case calculations showed that code gives satisfactory results for all parameters behavior. The main discrepancies were get for cladding temperature behavior at elevation 2.7m, where the calculated value exceeded the measured datum by about 75K. Computed quenching time for this elevation is much higher than experimental ones. For other levels accordance between experimental and RELAP data is rather good. Sensitivity analysis of results of calculations to input data showed that radial bundle nodding was inexpedient and it leads to less realistic results than at modeling of the bundle by one 

channel.

iv
1. INTRODUCTION

One of the main processes determining the behavior of fuel element during the accidents is the 

reflooding process, at which one they are cooling at the expense of water supplied to reactor from 

emergency core cooling (ECC) system. VVER type reactors against PWR ones have ECC system, 

which supplies the water not only from the bottom of the core, but also from the upper plenum. 

This process is very difficult for mathematical modeling, so it seems reasonable to investigate it by 

separate ways: firstly down-to-top reflooding, then top-to-down one and then combined process. 

Such researches are carried out now in EPPE at assemblies modeling an active zone of VVER reactors. 

Results of these investigations could be used for thermohydraulic codes assessment. Presented work 

such assessment have been done for RELAP5/MOD3 (version 3.2.2 Gamma), which consist an 

improved reflooding process model developed at Paul Scherer Institute using the experiment carried 

out at 37-rod VVER like assembly with down-to-top reflooding at IPPE in 2000. 

2. TEST FACILITY DESCRIPTION 

2.1 Circulation loop 

Principal scheme of experimental loop is shown at Fig. I A of Appendix A, which contents all necessary 

data for carrying out the calculations. 

Water from tank (1) is supplied by centrifugal pumps (2) through the block of regulate valves with 

electric drive (B4) and B4(r) into electric heater (19) where water heats until the given temperature. 

Flowrate value is measured by set of two orifices, which are established sequentially on line of water 

supply to the test section (10). In automatic monitoring mode the given water flowrate is supported 

with the help of a valve electric drive B4(r). Distribution valves (4) established after a preheater (19) 

allows at an opened valve A and closed valves B and B and ball plug to route the flow to the test 

section (10), or to return into the tank (1) through the bypass line, which has the cooler (11) and stop 

valves (B6). Before the inlet of test section (10) is placed the throttle flowmeter (6), which is the 

indicator of switching of bang-bang valve (4) and beginning of water supply into the test section. 

Separated in the upper plenum of the test section liquid collects in the tank of entrained water (7), 

connected by pipe with the bottom of the upper plenum. Vapor from the upper plenum passes through 

the special device with a developed surface, electric heater (15) where the remained non separated 

water evaporates, flowmeter orifice (6) and trough the vapor pressurizer (13) goes to condenser (16) 

and tank (1). The pressure in a system is established with the help of a steam compensator (13). Its 

regulation implements with the help of a valve (B9) and (B9r). If pressure exceeds given value, relief 

valve at compensator (13) opens. 

2.2 Test section 

Test section (TS) scheme is shown at Fig. 2A. It consists of vessel, upper and lower plenum. Vessel is 

made of hexahedral tube with inner described diameter equal 91.4 mm and wall thickness 3.3 mm. 

Vessel wall temperature is measured by 12 thermocouples at outer surface in four levels (692, 2038, 

2732, 3500 mm from heater zone beginning) three thermocouples in level. There are three rings along 

the vessel for pressure tapoff. 

Upper plenum intended for inertial phase separation of two phase flow coming out from the test section 

represents the cylindrical vessel (V=30000sm3). Gills arranged at the top of the plenum before an 

assigning nipple serve for additional phase separation. Separated water collects in the circular slot at 

the bottom of upper plenum and through the inclined opening flow off into the tank of entrained liquid. 

The bottom of upper plenum consists of two flanges lower of which serves for electric current supply to 

rod bundle and simultaneously for upper rod bundle grid modeling. Thickness of this grid is 20mm and

I
I L

cross section area is near the grid area value. The nipple by an altitude of 100 mms and inner diameter 84-87mm fastens to the same flange. It models an upper part of reference VVER assembly. At the outlet of this nipple arranged the perforated plate 20mm thickness with 121 holes (109 and 12 hole 5.5mm and 3.5 mm diameter accordingly), which models the plate arranged at the outlet of the core of reference reactor. Cross section area of plate holes per one rod is near the reference reactor one. There are pipe connections in upper plenum and outlet nipple (fairlead) for thermocouples lead- in and 

pressure measurement. 

Lower plenum represents a cylindrical vessel by inner diameter of 120 mm and altitude of 185 mm. For heat losses reducing vessel and plenums are isolated 20mm thickness high-temperature isolator (heat conduction coefficient equals to 0.05 Wt/(m K), heat capacity - 992 Kj/(kg K), density - 144 kg/mi3 at temperatures 123+1523 K). There are four thermocouples at the outer surface of the isolator 

at different locations along the vessel for heat losses control. 

2.3 Rod bundle 

Rod bundle models the VVER assembly and consists of rod bundle of 37 rod imitators with indirect heating with heated zone length 3530mm. 

Rod imitator (Fig. 4A) consists of stainless steel cladding with outer diameter 9. 1mm and inner diameter 7.9mm inside, which are placed nichrome heater and six chromel-alumel thermocouples with 

isolated junction. There are three types of rod imitators: in imitators of A type thermocouples placed at six locations along the length (one thermocouple for one level), in imitators of B and C type they are located in pairs at three locations (Fig.5A). Electric isolation used in all imitators is oxide magnium. Heater is made from nichcrome rod of variable cross section at the ends of that are welded copper current supplyes. Average along al 37 rods length axial nonuniformity is equal Kz= 1.60. Main characteristics of imitator are presented at tables Al, A2, A3 of Appendix A. Rod bundle was maked up from imitators, which has identical characteristics. Relative scatter of rod power for 37 rods 

is less than 10%. 

Besides upper grid there are 15 grids along the rod bundle, distance between which is 225mm. The rods in bundle replaced at triangular spasing with pitch equal to 12.75mm. Cross sectional area in the narrowest part is 3328 mm 2. There are thermocouples in the cells and at the 

grids . Table I shows the main geometrical characteristics of the test section The initial geometrical conditions for the test are the following: inner circumscribed diameter of the vessel - 91.4mm, 

inner vessel width across fields - 81.8mm, 

average for 37 rods rod diameter - 9 .14mm. 

Table 1 

Cross section area D hydralics D heated 

Support Rod Grid Grid-current Perforated 

grid bundle supply plate A-A B-B C-C AJ-AL E-E B-B B-B 

mm 2 mm2 mm2 mm 2 mm 2 mm mm 

2719 3328 2719 2438 2695 9,95 12,53 1 1 1 1 -1 (121 holes) I

2
2.3 Measurement system

Test loop and assembly model are arranged by necessary amount of sensors and control system to 

measure the following parameters: inlet and outlet test section pressures and temperatures, water 

temperature and massflow at test section inlet, vapor temperature and massflow at its outlet, rod 

cladding and vessel wall temperatures, pressure drops at heated part of test section and tank of 

entrained liquid. Measurement scheme is presented at Fig.7A of Appendix A. 

The Total parameters measurement error in the test was compounded as: pressure - 0,5 %; flowrate 

2,0 %; pressure drop - 1,0 %; power - 1,0 %; temperature - 1,0 %. 

2.5 Test procedure 

* Loop for reflooding investigation is filled with water from tank (1) with use of centrifugal 

pumps (2) and blowed out to reduce air. 

* Using block of regulation valves (12) necessary flowrate through the test section 

established. Water heating at the inlet of test section realized by switching on electrical heater 

(19). Nominal pressure in the loop is supported by valve B9(r). Then power stepwise increased. 

At different power levels parameters required for pressure drop measurement and verifying 

mass and energy balance were registered. 

* Electrical power reduced to zero. With using bang-bang valve water flow trough the test 

section stopped and water flow directs to tank (1). 

* Drainage valves opened and water flows out from the test section, tang of entrained liquid 

and vapor compensator (13). The remained liquid level was near the beginning of heater zone of 

rod bundle. 

* Heater (15) switched on for heating-up pipeline before vapor flowmeters. 

* Temperature at the inlet of test section checked. 

* Information gathering computer system and power control system switched on. 

* Test section power increased until -40+.'50% of nominal value. 

* Test section power increased until nominal value in automatic mode. 

* After reaching of specified temperature (any rod cladding temperature) began water supply 

to the test section and power decreased according to specified curve. Valve B 14 closed. 

* Switching on of water flowrate trough the test section (beginning of reflooding process) is 

controlled by flowmeter indication at line of water supply. 

• Parameters supporting during the process in given limits carried out in automatic (power) 

and manual mode (flowrate, pressure, inlet temperature). 

* Test stopped when all thermocouples fixed the rewetting of all rods and power switched out. 

3. TEST SCENARIO AND INITIAL CONDITIONS 

Second Russian Standart Reflooding Problem is the reflooding experiment from down to top of 37-rods 

bundle of full length scale VVER like rod assembly with fixed cooling water supply. 

3.1 Test scenario 

The initial conditions of test section was the following: lower plenum and lower rods (unheated part) 

part were filled with water 50'C and other part and upper plenum - with saturated vapor. 

o Power increasing for given value and rods heating to start temperature.

3
_

"* After reaching of starting temperature power decreasing began and switched on water supply 

to the test section. 

"* Test stopped at rod temperatures reached saturation temperature. 

3.2 Starting values of main parameters 

"* Upper plenum pressure - 0,246 MPa; 

"* Cooling water temperature - 51°C; "* Water velocity - 4.91 sm/s; "• Average linear heat flux density at maximal heat production zone before water supply 

-1,77 kWt/m. Reproducibility of such characteristics as maximal cladding temperature and quenching time in 

identical tests was near 1%. 

Heat losses defined in special steady-state tests describes by formula: Qoss:=4,7.l0 3

(T, -T 0 ) kWt, 

where (TJ T,,) - difference between average along the vessel length temperature and air one. 

4. NODALIZATION SCHEME DESCRIPTION 

Heat production in different rod simulators reviewing (Table Al) allows to come to conclusion, that despite of some scatter of axial distribution for different rods it seems quite reasonable to model all 37 rod bundle as the set of identical rods with average on all 37 rods axial heat distribution. Thus test section was modeled as one channel of "pipe" type devided into 15 parts along the length. Two heat 

structures connected with this channel modeled 37 heated rods (heat production equals zero at upper subvolume) and vessel wall. Upper plenum was modeled by two volumes "branch" type, which modeled upper perforated plate and upper volume where phase separation occurred. Down volume was connected with heat structure, modeled perforated plate. Inlet water temperature and its flowrate were set in the elements "tmdpjun" and "tmdpvol", connected with lower plenum modeled with element 

"branch" type. 

5. Results of calculations 

Calculations have been performed by RELAP5/MOD3.2 Gamma, which contents PSI reflooding model. At initial conditions there were established fixed distribution of vapor and heat structures 

temperatures - 2.46Mpa and 400K. The power bringed to test section began to increase and at time 139s inlet flowrate increased from zero up to 0.16kg/s. Power was changed according to experimental curve. Figs. 2-7 shows the results of calculations for three "A" type rods : .N'o 19,22 and 27, for which 

were made the detailed cladding temperature measurements along the length .Table 2 shows the 

coordinates of thermocouples location. 

Table 2 

Thermocouple location, mm 

Section/ Rod 19 22 27 

H=I 57 117 184 

H=2 513 690 698 

H=-3 1100 1215 1222 

H=4 2212 2203 

H=5 2704 2734 2722 

H-6 3505 3501 3477

4
It is clear that the coordinates of thermocouples location some differed for on section and naturally 

their indications would be different too. But this difference is too small, as thermocouples locates near 

the end of plate zone of heat distribution. For more larger difference could play role their radial 

position. So the rod 19 is placed in the middle of bundle, rod 22 in the outer row near the vessel wall 

and rod 27 is placed in the second row from the center.

Upper plenum

Vessel 

wall

Fig.1 Nodalization scheme of test section

5
400 n300 -•

200 -

100 -

0

A

100

-s---Rod N19, ex periment 

SRod N,22, oeq eriment 

Rod N27, exp-en t 

- RELAP, baseoase

200 

TbiR

300 400

Fig. 2 Rods cladding temperature behavior at H=1. Base case calculation and experimental data

300

200

100

100 200 300 

Time, s

Fig. 3 Rods cladding temperature behavior at H=2. Base case calculation and experimental data

6

I I
500 -F- . . . ... . .

I I 

-I I 

I i 

11=3 

400 - - -RodN19, L-perimt 

IE) Rod N22, expiment 

24; Rod N27, experiment - -- RELAP, base r.s 

10O0 -- -

I I 

100 - -- -I - U - - - --- --

0I IF 

0- I I 

0 100 200 300 400 

Time,s 

Fig. 4 Rods cladding temperature behavior at H=3. Base case calculation and experimental data 

7

C u 12
800

600 - - --- 7- -

UI 

(U 

200 .H=4 

-E Rod N22, experiment 

- - Rod N27, experiment _ -- 

- RELAP,basecase 

0- I 

0 100 200 300 400 

Time, s 

Fig. 5 Rods cladding temperature behavior at H=4. Base case calculation and experimental data

8
600 -.- - - - - - -- -

I -, 

I / 

- - EA, bý r

I / I \ 

I I 

I 

200 100 

- -Rod N9, experiment 

Fig.-6 Rod N22, experiment 

- Rod N27, experiment 

RELAP, base case 

0--* I 

0 100 200 300 400 

Time, s 

Fig. 6 Rods cladding temperature behavior at 11=5. Base ease calculation and experimental data

co0-
400

H=6 

E3 Rod M9, experiment 

E - Rod N22, experiment 

- Rod N27, experiment 

- -------- - RELAP, basecase

0 100 200 

Time, s

300 400

Fig. 7 Rods cladding temperature behavior at H=6. Base case calculation and experimental data

Fig. 8-11 shows the same data but separately for each rod. The analysis of these data shows that 

accordance between them is rather good especially for down and middle part of rod bundle (until H=4). For upper section especially for H=5 code gives lower temperatures, but more longer duration of 

reflooding process. Specially clear it is visible at Fig. 11, at which quenching front position during the 

test is presented. It is clear that front velocity propagation is very well predicted for lower part of the 

bundle, but for upper part the descripancies between calculated and experimental values becomes 

larger. It must be noted that the experimental data for this part have significant scatter from 30s to 150s.

Fig. 11 - 13 shows pressure drop data along the test section: for down part of heated zone, upper part and 

total pressure drop for heated zone. One can see that total pressure drop predicted well enough, and for 

lower part calculated values are some lower experimental ones after 180s. Upper part pressure drops at 

first 300 s have different signs with closed rates of pressure drop increasing. Apparently the 

experimental data for this parameter is not correct and it is lowered approximately at 4kPa.

10

300 /t

200 

U

100

0
800 --

600 - ------

400

-5)

L-0 -. 

L.

1-0

Rod 19 

- - H=I 

S- H=2 S~H=3 

- - H=5 

A H=6 

--- -- H-1,RELAP 

------ -H-2, RELAP 

- - E- H=3, RELAP 

S-- - H-5, RELAP 

-- A-- H-6, RELAP

200 -- -- V

0

2-g2 

t1 c 4 -O0 200

Time, s

400 600

Fig. 8 Cladding temperature of rod N19. Base case calculation and experimental data

11

c-ccG
1 0 0 0 - .. . ..-.-. -.- ... 

Rod 22 

- - H=2 

- -H=3 

800 - - --

A H=5 

-*---- H=6 

-- +-- H=1,RELAP I 

-- --- -- H=2, RELAP 

600 - "3,RELAP -- - = 

Q -- e- H=4, RELAP 

A-,- H=5, RELAP 

- --- --- H=6, RELAP 

400 - - - _ 

200-4-4- - 4- - - --- -

0 

0 200 400 600 

Time, s 

Fig. 9 Cladding temperature of rod N22. Base case calculation and experimental data 

12

c-0-7
1000 - -- -.- ---- --- -. . 

Rod 27 

-U------ n1=3 

80 1H=4 

- H=5 ff // lkQ. x\11=6 

a 600 - -- -- - -- - +-- H=1,RELAP I 

_----- H=2,RELAP I 

(- - - -H=3, RELAP 

\ -- A-- -- H=4, RELAP 

t- E-- H=5.RELAP I 

400 - - - - --- H=6, RELAP I 

U 

- t

I I 

200 A L- - - -

0 200 400 600 

Time, s 

Fig. 10 Cladding temperature of rod N27. Base case calculation and experimental data. 

13

C-CO%
2I 

r

DPI 

- Experiment 

E- RELAP, base case 

-R- RELAP, Two rod model

V 

1

0 100 200 300 

Time, s

400

Fig. 11 Full pressure drop at heated zone

14

C()9

ftlI

30

20

03

10

0

-10
16 I 

I I 12 / - - - - - - -_

DP2 

-- - Experiment I 

RELAP, base case 

8 - - Line/Symbol PI4S 3 -_ 

S4L I / -

- i I I 

I ! 

0 100 200 300 400 

Thne, s 

Fig. 12 Pressure drop at upper part of the bundle

15
20

16

[ ~Expernient / • RELAP, base case 

12 - - -- 8- RELAP, Two rod model 

12 - - -j - - -

0 M - -LL -

-4-2 

I II 

0 100 200 300 400 

Time, s 

Fig. 13 Pressure drop at lower part of the bundle 

16

C-) I
4000

3500 --- ME- - - -0---- - [- - -- 

3000 - r -

U U 

2500 2500 -- - - - - -

200 I 

1000 v Front position, tun I 

I Experiment 

I RELAP, base case 

500 

01 

0 50 100 150 200 250 

Time, s 

Fig. 14. Quenching front position. Base case and experimental data 

6. SENSITIVITY ANALYSIS 

6.1. Radiation heat transfer influence 

It seems reasonable that radiation heat transfer between different rod is inessential, as their 

temperatures differ from each other too small during the process. However radiation could play role in 

outer rods row and vessel wall. For checking such influence the calculations have been performed with 

taking into consideration the radiation heat transfer. Rod bundle in this calculation was modeled as for 

base case by one channel multiplicity 37 and heat structure, which changed with radiation heat with 

vessel wall. The results of this calculations are presented at Fig. 15-16. 

17

cl7ý-
600

400

U 

I

200 

"U

0

-72

A

/ IA 

H=5 

B Rod N19, expoeiment 

E- Rod N22, experiment 

A Rod N27, experimett 

- RELAP, bas case - RELAP, with radiation

0 100 200 300 

Time, s 400

Fig. 15. Radiation heat transfer between rod bundle and vessel wall influence for H=5.

18
400 -,- - - -

I 

Q ~II 

- I 300 - -

4

U 

100- - - - - - H=6 1-Rod N19, experimaent 

-E Rod N22, experument I 

A Rod N27, experment I 

- -. . . . .- REL P, base case 

- +- -RELAP, wffi radiation 0 1 F, 0 I I 

0 100 200 300 400 

Time, s 

Fig. 16. Radiation heat transfer between rod bundle and vessel wall influence for H=6 

6.2 Axial power distribution influence 

Fig. 17-18 show the results of calculations, performed with different variation factor along the bundle 

for H=4 and H=6. For these calculations were chosen such variations factors, which corresponded to 

rods with its maximal and minimal values of all bundle rods. Maximal difference was got for H=4, but 

as one could see from Fig. 17-18 this difference is too small and discrepancies between experimental 

data and computed couldn't be explained by this factor.

19
800 -- - -- - - -

Kz influence, H=4 

4 ---- d--- RELAP, base case 

-e\--e RELAP, Kz=1.69 

600 - - - - - -- -- - RELAP, Kz=I.501 

- -- - - Experiment 

a I 

400 -t - - - - -

0 200 40 . . 600-• 

I I I 

I I I 

:6 I I 

I I 

0 200 400 600 

Time, s 

Fig. 17. Axial distribution influence on cladding temperature behavior for H=4 

20

C15
E 

I 

- -• - -ll -r - - • -I -. . -. -. - - -

200

Cz influence, 

+-RELA 

- RELA 

h-RELA 

Experi

L

H=6 

P, base case 

P, Kz=1.69 

P, Kz=1.501 

ment

F400

Time, s

Fig. 18. Axial distribution influence on cladding temperature behavior for 1H=6 

6.3 Radial power distribution influence 

Analysis of experimental data presented for example at fig. 7, shows that for upper bundle part radial 

position of the rod plays significant role. For example the earliest quenching takes place at the rods 

placed at the outer rod row. Quenching of the rods placed in the second from the vessel wall row 

occurred some later. The analogous results for type "B" rod presented at fig. 19. 

21

Co1

400 ---

300 --

I 

S 

U

200-

100

04

'-'I

0 600
400

-I

I 

R od type B H =6 

I-I -i • RodN 

-- I - •RodN2

-_+-PN --ROdN3

,s) 

U•

0 100 200 300

Time, s

Fig. 19. Rod of type "B" temperature behavior. Experimental data for H=4

For taking into account radial parameter the calculations have been performed with using modified 

nodalization scheme, in which whole rod bundle was divided into two parts: zone with all rods of outer 

row and the zone with the rest rods. Radiation heat transfer was taken into account for transfer between 

outer rods row and vessel wall, and radiation between outer rods and inner was neglected. Fig. 20 

shows the results of these calculations for upper section type "B" rods.

22

cii

L I300

L 

21 

26 

28- L 

37I

200

100

0

-100

-j 

-J

400
400--

300 - II - L -- - - -

1L 

100 -- L 

U I R cd type, B l1=6 -- -- -- -I Rod N 21I 

-- -- -- 'd Rod N 26 i 

0 = A - -Rod N 28 L ------ ------

-- +--J RodN37 I 

- E - RELAP, basecas 

e R E LAPT wo rod nwodel. cental rods 

SR E LAP, two rods m odel, outer row of rpds 

-100 1 I i 1 

0 100 200 300 400 

Time, s 

Fig. 20. Rod of type "B" temperature behavior. Experimental and calculated data for H=6 

Fig. 21 shows the analogous data for type "A" rods. One can see that though two groups cladding behavior are practically coincided, in a general way their behavior some change and quenching of 

upper pan of the rods occurs some earlier than for case of bundle modeling with one channel. Fig. 22

23 shows the results for "A" group rods at H=5 and H=4. 

23 

01%
400

100 200 

Time, s

Fig. 21. Rod of type "A" temperature behavior. Experimental and calculated data for H=6

24

\ I 

I I

300

2 200 

PC

100

0

H=6 

- Rod N22, experiment 

S- Rod N27, experiment 

base -RELAP, case

- - + - - RELAP, two rods model, outer rods 

- -- - - RELAP, two rods model, central rods

1

0 300 400
600 - ..- - - - - - - -

I \ 

I I 

20 --- -/ - --- I 

1H=5 - B Rod N19, experiment 

- Rod N22, experiment 

0 - -ý* 2E Rod N27, experiment H - -

-- -RLAP, base case 

4RELAP, Two rods model, outer rods I 

A RELAP, Two rods model, central rods 

0 100 200 300 400 

Time, s 

Fig. 22. Rod of type "B" temperature behavior. Experimental and calculated data for H=5 

25 

c-io
800

600- - - -1- -- - - -

I t S400 -- - - -- I

200 - - - -. . L

H=4 

E) Rod N22, experiment 

- -1 Rod N27, experiment 

0-- ----- ------- RELAP, base case - - -

-RELAP, two rod model, outer rods I 

- - RELAP, two rods model, central rods 

0 100 200 300 400 

Time, s 

Fig. 23. Rod of type "B" temperature behavior. Experimental and calculated data for H-4 

One can see from Fig. 21 radial dividing reduces quenching time for upper section (H=6), difference 

between temperatures behavior being practically neglecting. Difference from experimental and 

calculated data remained essential. 

For section H=5 was obtained qualitatively incorrect behavior cladding temperature for both rod rows: 

more earlier quenching of inner rods. For both rows was obtained earlier quenching than for base case 

calculation. And for this case quenching times were obtained larger than experimental ones also. 

For H=4 (Fig. 23) using two-channel model changed the results insignificant. Fig. 24 shows the results of quenching front propagation with two-cannel model using. Apparently 

from this figure quenching of bundle lower part occurred some later, than in experiment and in base 

case calculation. For upper part calculations wit two-channel model gave earlier quenching, than for 

base case and as a rule inner part quenching occurred earlier than quenching of outer part. 

26

r-71
4000

3500 

3000 

2500 

2000 

1500 

1000 

500 - RELAP- base case 

RELAP - two rods model, central rods 

- - -- - RELAP, two rods model, outer rods 

0 50 100 150 200 250 300 

Time, s 

Fig. 24. Quenching front position. Two-channel model results and experimental data 

Fig. 25-26 shows the results of calculations of pressure drop on the bundle for base case and two channel model. One can see pressure drop behavior for two-channel model characterized considerable 

oscillations not fixed in the experiment and accordance between calculated results and experimental 

data are less than for base case. 

27

OYE7-
DPI 

--- -- Experiment 

-e-- RELAP, base case 

-P RELAP, Two rod model

-j if4

'V F 

2

0 100 200 

Thie, s

300 400

Fig. 25. Pressure drop at the heated zone. Experimental data and results of calculations with two

channel scheme

28

30

20

0

10

0

-10
20

16 1 1 

DP3 

- Experiment 

- G RELAP, base case 

12 -• tRELAP, Two rod model 

128 - - • -- -- - -

044 

-4 - '-- 

0 100 200 300 400 

Time, s 

Fig. 26. Pressure drop at lower part of heated zone. Experimental data and results of calculations 

with two-channel scheme 

7. RUN STATISTICS 

Fig. 27-28 illustrate code efficiency where time step variation and CPU time during the calculation are 

presented. Grind time is evaluated as 

CPU/(C*DV)= 0,000228, where 

C= 18 - volumes number, 

DT = 95992 time steps number, 

CPU = 395 s - CPU time.

29
400 

300 

S200 

100 1 F 

0- I 

100 

0 100 200 300 400 

Time, s 

Fig. 27 CPU time during the test calculation

30
0.2 -

0.16 -

S 0.12 -

0.08 -

0.04 

0 100 200 300 400 

Time, s 

Fig. 28 Time step behavior during the test 

8. CONCLUSIONS 

The calculations down to top reflooding process at 37-rod bundle with code RELAP5/MOD3 (version 

3.2.2 Gamma) showed that code gives satisfactory results for all parameters behavior. The main 

discrepancies were get for cladding temperature behavior at elevation 2.7m, where the calculated value 

exceeded the measured datum by about 75K. Computed quenching time for this elevation is much 

higher than experimental ones. For other levels accordance between experimental and RELAP data is 

rather good. 

Sensitivity analysis of results of calculations to input data showed that radial bundle nodding was 

inexpedient and it leads to less realistic results than at modeling of the bundle by one channel.

31
REFERENCES 

1. Lozhkin V.V., Sudnitzyn O.A., Kulikov B.I., etc. Experimental and Theoretical Investigation of heat transfer at simulating of loss of coolant accidents with bottom-up reflooding on 37-rod assembly model 

of VVER. IPPE Report / N 9648, 1998.

32
Appendix A. TEST FACILITY SCHEMES

Fig. IA. Loop scheme 

1- tank, 2 - pumps, 3,9 -steam generators, 4 -toggle valve, 5 

connectors, 6 - flowmeter orifices, 7 - entrained liquid tank, 

10 - test section, 11- cooler, 13 - steam pressurizer, 15 

electric heater, 18 - downcomer model, 19 - preheater.

33
3n

Fig. 2A. Test section scheme 

I- vessel; 2 - lower plenum; 3 - upper plenum; 4 - separator; 5 - louver- 6 - plate connected with 

current lead.; 5 - louver; 6 - plate connected with current lead.

34
Fig 3A. Upper plenum with current lead plate (1) and perforated plate (2) 

35
III 

Fig. 4A. Rod imitator with indirect heating. 1, 8 - copper rods, 2 - thermocouples, 3 

lead. 

cladding, 4 - NI, Cr heater, 5 - pinch barrel, 6 - pulling wire, 7 - MgO, 8 - 9 - cone current

36
2017 2017 ,.2038 

S8 2067 1997 

"1762 1527 

7 -507 n 1507 

1507 

1285 

6 1252 1202 

-5 762 

99792 5 S76 0 4 742W 692.792 

692 

3 487 

2 232 182 

0 o_ 1 1 _ __ . _. _ __ 

0 K 0 

A B C 

Grid Spacers 

Fig. 5A. Axial power profile and thermocouple arrangement along the height for the test 

section KB-37.1 

A, B, C, - imitator types; IK - vessel; H - insulation; 

* - wall mounting thermocouples; 

o - fluid thermocouples; 

r- a distance from the bottom of the heated zone*(rough values); 

2321 232 - a distance from the bottom of the heated zone to the bottom of a grid 

spacer (measured before the tests). 

• - the correct values specified in Table A-2.

37
a)

b) 

6 '----< 8 •- 1 12 14 

.. , 166 -: 18 20' 22 • - 21 V-/ 2 

'\ 2 10 " 2 / 15 3 14 ,•394•1.6i) •9 2 .6987i• 4 , 

'091 .098,1 01?' 0947 0.90 09 

26 2 " 3 0 N--35 3 3 7 

2 19 •',: 29 3 3um3er 2- •18 5 7 20mber2 8o 

41 43 >-< < 7 '3" 4 51 

40 18~-4 46 20 48 24 5 

30 14 236 (27 2 

66- grid 60 623o 

' 9 3 31 3 2 35I 3 

661 8 67ý >9 7 0 72 

65 4 - vse 69nd" i o tem/u73 

33 24 - 35 36 37obe 

NA ý98, 00 0 '64 003/,,\1 020 

37. (to view) 6 

19 rod 30 number, O9 ~ 98 98ltieowr 

codciepoe 6)9, 00)-j 

38
O Pressure drop O Static Pressure 

OG Temperature O Flow 

TW 

V a lv e 

Q Throttle 

@ Control 

valve 

Fig. 7A. Instrumentation for the test section KB-37.l

39
P. KP a; G, KD/hr, T, °C

100 200

200 

N,KWr

300 cT 400

Fig 8A. Main parameters behavior during the experiment

40

600 

500 

400 

300 

200 

100

100 

0

0
Table A-1 Bundle KB 37.1. Imitator test results

Rod Nu Inac Identifica 

mbe tive tion dmax d Rpassp. Rmeas. Kzi KNI KZH= 

r of Tc Kz*K 

Tc N 

1 6 B-38 9.16 9.1 0.569 0.567 1.592 0.986 1.57 0.98 

21 

16 6 A-40 9.12 9.1 0.566 0.561 1.589 0.996 1.58 0.99 

1 

34 5 5 C-12 9.13 9.1 0.575 0.575 1.620 0.972 1.57 0.98 2 1 

2 4 1,3 A-49 9.13 9.1 0.552 0.552 1.570 1.012 1.59 0.99 

1 

5 6 B-35 9.14 9.1 0.560 0.559 1.572 1.000 1.57 0.98 

1 

10 6 C-30 9.25 9.2 0.564 0.564 1.660 0.991 1.64 1.03 

3 

23 6 B-29 9.15 9.1 0.569 0.568 1.676 0.984 1.65 1.03 

4 

29 6 A-31 9.16 9.1 0.562 0.558 1.684 1.001 1.69 1.05 

4 

35 6 C-33 9.16 9.1 0.563 0.560 1.593 0.998 1.59 0.99 

4 

6 6 C-48 9.11 9.1 0.575 0.572 1.585 0.977 1.55 0.97 

10 1 

17 6 C-6 9.19 9.1 0.580 0.573 1.521 0.975 1.48 0.93 

9 

30 5 6 B-14 9.16 9.1 0.561 0.560 1.597 0.998 1.59 1.00 

2 

7 6 C-45 9.13 9.1 0.562 0.557 1.596 1.003 1.60 1.00 

_ 12 12 1 

11 6 B-47 9.14 9.1 0.558 0.554 1.569 1.009 1.58 0.99 

2 

24 6 B-32 9.18 9.1 0.569 0.558 1.689 1.001 1.69 1.06 

6 

12 6 A-19 9.14 9.1 0.575 0.576 1.522 0.970 1.48 0.92 

13 3 1 

18 6 A-7 9.15 9.1 0.573 0.573 1.655 0.975 1.61 1.01 

3 

25 6 C-18 9.14 9.1 0.598 0.589 1.578 0.949 1.50 0.94 

3 

19 6 A-1 9.13 9.1 0.560 0.560 1.571 0.998 1.57 0.98 

2 

26 6 B- 2 9.15 9.1 0573. 0.527 1.565 1.060 1.66 1.04 

4 

41
20 6 C-3 9.14 9.1 0.512 0.506 1.582 1.104 1.75 1.09 

3 

13 6 B-17 9.15 9.1 0.592 0.590 1.586 0.947 1.50 0.94 

2 

31 6 C-21 9.17 9.1 0.574 0.567 1.509 0.986 1.49 0.93 

4 

27 6 A-34 9.15 9.1 0.534 0.527 1.573 1.060 1.67 1.04 

4 

14 3 2,3, C-24 9.20 9.1 0.574 0.570 1.667 0.980 1.63 1.02 

4 8 

32 6 C-27 9.17 9.1 0.569 0.570 1.645 0.980 1.61 1.01 

7 

21 6 B-23 9.18 9.1 0.566 0.562 1.530 0.994 1.52 0.95 

7 

8 6 A-46 9.14 9.1 0.558 0.552 1.584 1.012 1.60 1.00 2 

36 6 A-25 9.33 9.1 0.562 0.557 1.662 1.003 1.67 1.04 

9 

33 6 C-36 9.15 9.1 0.555 0.551 1.690 1.014 1.71 1.07 

4 

28 5 2 B-20 9.12 9.1 0.551 0.548 1.665 1.020 1.70 1.06 

7 

15 6 C-39 9.12 9.1 0.568 0.561 1.599 0.996 1.59 1.00 

1 

9 4 3,4 B-44 9.20 9.1 0.562 0.558 1.584 1.001 1.59 0.99 

7 

3 3 2,3, C-9 9.13 9.1 0.568 0.565 1.614 0.989 1.60 1.00 

5 2 

37 6 B-26 9.14 9.1 0.549 0.545 1.501 1.025 1.54 0.96 

3 

22 6 A-22 9.15 9.1 0.557 0.55 1.638 1.003 1.64 1.03 

2 

4 4 1,3 C-42 9.17 9.1 0.549 0.544 1.594 1.027 1.64 1.02 

Average values 9.14 0.559 1.601 1.60

42
Table A-2 Thermocouple arrangement in Bundle KB-37/1

Thermocouple 

Rod Rod 1 2 3 4 5 6 

Type 

mm mm o ,mm mm o 

A-1 19 57 186 513 225 1110 184 ----- 2704 300 3505 1 0 

A-7 18 180 298 ----- 1194 182 2226 120 2725 46 ----

A-19 12 197 267 688 222 1215 196 2207 128 2727 108 3486 0 

A-22 22 117 240 690 103 1215 20 2212 200 2734 164 3501 0 

A-25 36 193 280 704 330 1233 120 2226 90 2741 70 3500 0 

A-31 29 188 140 694 65 1217 290 2207 160 2725 25 3483 0 

A-34 27 184 290 698 200 1222 115 2203 306 2722 142 3477 0 

A-40 16 150 110 659 350 1187 273 2195 164 2721 70 3490 0 

A-46 8 154 260 666 90 1190 356 2184 220 2706 108 3468 0 

A-49 2 ----- 682 110 2192 208 2710 120 3467 0 

Thermocouple 

Rod Rod 1 2 3 4 5 6 

Type lmm Io ,mm •o lmm o l~mm o lmm o lm ° 

B-2 26 942 68 945 230 2063 194 2067 48 3362 197 3365 0 

B-14 30 774 296 775 102 2048 242 2048 68 3313 195 ----

B-17 13 773 184 773 342 1998 268 1997 103 3306 170 3306 0 

B-20 28 793 350 ......- 2026 40 2027 230 3349 183 3348 0 

B-23 21 779 247 779 62 2013 15 2014 197 3334 179 3333 0 

B-26 37 820 252 819 60 2022 86 2023 275 3323 188 3325 0 

B-29 23 779 338 780 140 2012 185 2010 10 3326 188 3326 0 

B-32 24 792 62 790 238 2021 178 2022 8 3341 180 3341 0 

B-35 5 764 125 1993 138 1991 325 3317 183 3316 0 

B-38 1 756 334 757 138 2010 286 2010 100 3326 195 3325 0 

B-44 9 756 290 756 95 ----- 1965 6 3306 0 ----

B-47 11 741 125 741 304 2024 276 2024 98 3335 175 3335 0 

Thermocouple 

Rod Rod 1 2 3 4 5 6 

Type 

I'mm o I0mm o mm m o Imm o I mm o 

C-3 20 1435 330 1437 150 2001 80 2000 250 2748 186 2746 0 

C-6 17 1513 250 1514 78 2023 270 2023 70 2736 180 2737 0 

C-9 3 1487 85 ----- 1990 335 1987 170 ----- 2692 0 

C-12 34 1517 210 1518 22 2027 330 2026 165 ---- 2729 0 

C-18 25 1414 184 1414 338 1971 218 1971 32 2731 178 2730 0 

C-21 31 1488 245 1491 64 2000 248 2001 80 2718 162 2718 0 

C-24 14 1232 248 ...............- 2461 50 2461 -10 

C-27 32 1505 298 1505 132 2014 280 2015 113 2733 220 2732 0 

C-30 10 1527 290 1524 95 2039 214 2038 46 2759 200 2760 0 

C-33 35 1495 130 1493 307 2012 224 2012 46 2736 168 2736 0 

C-36 33 1511 160 1510 348 ----- 2018 55 2737 175 2739 0 

C-9 15 1488 82 1487 254 2004 285 2003 115 2729 170 2730 0 

C-42 4 ----- 1517 232 2020 235 2022 75 2737 185 ----

C-45 7 01476 05 1476 275 1987 20 1987 205 2715 176 2715 0 

C-48 6 1 1484 270 2004 12 2003 190 2728 170 OH

43
44
Ta6.nuua A-3. Bundle 37.1. Axial power profile

N Rod Type Zone Number 

1 2 3 4 5 

L 0 Kz L 0 Kz L 0 Kz L 0 Kz L 0 Kz 

1 19 A-1 695 3.85 0.657 525 3.23 0.934 1056 2.49 1.571 524 3.3 0.894 730 3.95 0.624 

2 18 A-7 785 3.9 0.576 501 3.00 0.973 1011 2.30 1.655 496 3.00 0.973 740 3.85 0.591 

3 12 A-19 774 3.58 0.642 494 3.05 1.022 997 2.50 1.522 494 3.05 1.022 776 3.80 0.659 

4 22 A-22 768 3.80 0.626 492 3.10 0.941 1005 2.35 1.638 508 3.10 0.941 757 3.85 0.61 

5 36 A-25 768 3.80 0.609 494 3.00 0.977 1003 2.30 1.662 507 3.10 0.915 759 3.85 0.593 

6 29 A-31 751 3.80 0.617 501 3.20 0.87 1013 2.30 1.684 503 3.10 0.927 762 3.85 0.601 

7 27 A-34 835 3.75 0.671 487 3.05 1.015 952 2.45 1.573 487 3.10 0.982 777 3.80 0.654 

8 16 A-40 747 3.75 0.635 495 3.00 0.992 1023 2.37 1.589 505 3.10 0.929 760 3.80 0.618 

9 8 A-46 757 3.75 0.633 485 3.00 0.989 1023 2.37 1.584 504 3.05 0.956 761 3.80 0.616 

10 2 A-49 769 3.75 0.643 493 3.00 1.005 1003 2.40 1.570 500 3.05 0.972 765 3.80 0.626 

11 26 B-2 770 3.8 0.667 499 3.2 0.940 1043 2.48 1.565 516 3.3 0.884 702 3.84 0.653 

12 30 B-14 763 3.75 0.638 494 3.00 0.997 1008 2.37 1.597 498 3.10 0.933 767 3.80 0.621 

13 13 B-17 765 3.85 0.616 499 3.00 1.015 1019 2.40 1.586 501 3.10 0.95 745 3.85 0.616 

14 28 B-20 786 3.85 0.620 484 3.20 0.898 995 2.35 1.665 502 3.15 0.927 764 3.80 0.637 

15 21 B-23 747 3.85 0.645 498 3.10 0.995 1020 2.50 1.530 501 3.10 0.995 764 3.85 0.645 

16 37 B-26 802 3.90 0.642 475 3.10 1.016 998 2.55 1.501 482 3.05 1.049 783 3.80 0.676 

17 23 B-29 741 3.90 0.583 498 3.15 0.893 1026 2.30 1.676 510 3.10 0.923 756 3.80 0.614 

18 24 B-32 760 3.85 0.603 485 3.20 0.873 1020 2.30 1.689 501 3.10 0.93 765 3.85 0.603 

19 5 B-35 736 3.75 0.644 503 3.05 0.974 1026 2.40 1.572 507 3.10 0.942 758 3.80 0.627 

20 1 B-38 733 3.75 0.625 495 3.05 0.945 1037 2.35 1.592 504 3.05 0.945 761 3.75 0.625 

21 9 B-44 732 3.75 0.633 501 3.00 0.989 1032 2.37 1.584 504 3.10 0.926 760 3.80 0.616 

22 11 B-47 759 3.70 0.660 493 3.05 0.971 1013 2.40 1.569 498 3.10 0.940 767 3.75 0.643 

23 20 C-3 765 3.9 0.676 520 3.35 0.917 1037 2.55 1.582 538 3.45 0.864 670 4 0.643 

24 17 C-6 749 3.90 0.625 495 3.10 0.989 1022 2.50 1.521 510 3.05 1.022 754 3.80 0.658 

25 3 C-9 770 3.82 0.611 495 3.05 0.958 1000 2.35 1.614 510 3.00 0.99 755 3.80 0.617 

26 34 C-12 757 3.7 0.626 499 2.95 0.985 1009 2.3 1.620 500 3.00 0.952 765 3.8 0.593 

27 25 C-18 692 3.70 0.61 517 2.90 0.992 1056 2.30 1.578 536 3.00 0.927 730 3.75 0.593 

28 31 C-21 762 3.80 0.653 495 3.10 0.982 1008 2.50 1.509 503 3.00 1.048 762 3.80 0.653 

29 14 C-24 750 3.80 0.611 514 3.10 0.918 1001 2.30 1.667 515 3.10 0.918 748 3.80 0.611 

30 32 C-27 754 3.8 0.618 499 3.1 0.929 1011 2.33 1.645 497 3.1 0.927 762 3.8 0.618 

31 10 C-30 754 3.80 0.608 503 3.10 0.914 1010 2.30 1.660 497 3.05 0.944 766 3.80 0.608 

32 35 C-33 738 3.80 0.609 500 3.00 0.978 1027 2.35 1.593 502 3.00 0.978 763 3.80 0.609 

33 33 C-36 745 3.9 0.588 495 3.2 0.873 1025 2.3 1.69 504 3.1 0.93 761 3.85 0.603 

34 15 C-39 758 3.75 0.639 486 3.05 0.996 1021 2.37 1.599 502 3.10 0.935 763 3.80 0.622 

35 4 C-42 775 3.80 0.636 480 3.05 0.987 1010 2.40 1.594 505 3.10 0.956 762 3.85 0.620 

36 6 C-48 748 3.75 0.623 500 3.0 0.973 1017 2.35 1.585 508 3.0 0.973 756 3.75 0.623 

37 7 C-45 747 3.75 0.638 495 3.05 0.964 1023 2.37 1.596 508 3.10 0.933 758 3.80 0.621 

45
Appendix B. INPUT DECK FOR BASE CASE 

= Reflooding for 37 rod assembly 

Q=48 KWT 

0000100 new transnt 

0000105 1. 2.

0000201 0.5 1.0e-08 0.001 

0000202 50.0 1.0e-08 0.20 

0000203 130.0 1.0e-09 0.005 

0000204 200.0 1.0e-09 0.005 

0000205 270.0 1.0e-09 0.005 

0000206 280.0 1.0e-09 0.002 

0000207 400.0 1.0e-08 0.005

0003 500 500 10000 

0003 50 5000 1000 

0003 200 5000 1000 

0003 2000 5000 1000 

0003 2000 5000 1000 

0003 2000 5000 1000 

0003 2000 5000 1000

20800001 cputime 0 

20800002 dt 0 

0000401 time 0 ae null 0 0.0 1 

0000402 time 0 ge null 0 130.0 1

volume data cards * 

*

water tank 

0020000 "tank" tmdpvol 

0020101 1.0 1.0 0.0 0.0 90.0 1. 0. 0. 10 

0020200 103 

0020200 103 

0020201 0.00 2.46000e5 324.15 * 

junction no. 4 (lower plenum to core) 

V inlet =4.91 smnc,G= 580 kg/h =0.16 kg/s 

0010000 "jun 1" tmdpjun 

0010101 002000000 006000000 0.0113 

0010200 I 402 

0010201 0.0 0.0 0.0 0.0 

0010203 1000.0 0.16 0.0 0.0

"*crdno name type 

0060000 in branch 

*crdno jun.no ctrlw 

0060001 1 1 

*crdno area length volume h.ang v.ang elev rgh dhyd tlpvbfe 

0060101 0.0113 0.185 0.0 0.0 90. 0.185 4.0-5 0.0 0010000

46
*crdno ebt pressure quale 

0060200 002 2.460e5 0.0 

*crdno from to area floss rloss efvcahs 

* Area for 37 rod 

0061101 006010000 004000000 0.003328 0.0 0.0 0001100 

*crdno flowf flowg in.vel 

0061201 0.0 0.0 0.0 

* core * 

0040000 "core" pipe 

0040001 15 

* vol area 

0040101 0.003328 1 

0040102 0.003328 2 

0040103 0.003328 3 

0040104 0.003328 4 

0040105 0.003328 5 

0040106 0.003328 6 

0040107 0.003328 7 

0040108 0.003328 8 

0040109 0.003328 9 

0040110 0.003328 10 

0040111 0.003328 11 

0040112 0.003328 12 

0040113 0.003328 13 

0040114 0.003328 14 

0040115 0.003328 15 

* junctions areas 

0040201 0.0027187 1 * 

0040202 0.0027187 2 * 

0040203 0.0027187 3 * 

0040204 0.0027187 4 * 

0040205 0.0027187 5 * 

0040206 0.0027187 6 * 

0040207 0.0027187 7 * 

0040208 0.0027187 8 * 

0040209 0.0027187 9 * 

0040210 0.0027187 10 * 

0040211 0.0027187 11 * 

0040212 0.0027187 12 * 

0040213 0.0027187 13 * 

0040214 0.0027187 14 * 

* L total =3.53m 

0040301 0.255 1 * 

0040302 0.255 2 * 

0040303 0.255 3 * 

0040304 0.25 4 * 

0040305 0.25 5 * 

0040306 0.25 6 

0040307 0.25 7 

0040308 0.25 8 

0040309 0.25 9 * 

0040310 0.25 10 *

47
0040311 0.25 11 * 

0040312 0.255 12 

0040313 0.255 13 

0040314 0.255 14 * 

0040315 0.237 15 * 

0040601 90.0 15 

0040801 0.0 9.07e-3 15 

0040901 0.1 0.1 14 

;k pvbfe 

0041001 01100 15 

tfcahs 

0041101 001000 14 

4 

0041201 102 2.46000e5 1.0 0.0 0.0 0 2 

0041202 102 2.46000e5 1.0 0.0 0.0 0 2 

0041203 102 2.46000e5 1.0 0.0 0.0 0 3 

0041204 102 2.46000e5 1.0 0.0 0.0 0 4 

0041205 102 2.46000e5 1.0 0.0 0.0 0 5 

0041206 102 2.46000e5 1.0 0.0 0.0 0 6 

0041207 102 2.46000e5 1.0 0.0 0.0 0 7 

0041208 102 2.46000e5 1.0 0.0 0.0 0 8 

0041209 102 2.46000e5 1.0 0.0 0.0 0 9 

0041210 102 2.46000e5 1.0 0.0 0.0 0 10 

0041211 102 2.46000e5 1.0 0.0 0.0 0 11 

0041212 102 2.46000e5 1.0 0.0 0.0 0 12 

0041213 102 2.46000e5 1.0 0.0 0.0 0 13 

0041214 102 2.46000e5 1.0 0.0 0.0 0 14 0041215 102 2.46000e5 1.0 0.0 0.0 0 15 

0041300 0 

0041301 0.0 0.0 0.0 14 

upper plenum 

•crdno name type 

2040000 out branch 

•crdno jun.no ctrlw 

2040001 1 l 

•crdno area length volume h.ang vyang elev rgh dhyd tlpvbfe 

2040101 2438.0e-6 0.1 0.0 0.0 90. 0.1 0.0 0.0 0010000 

section D-D/37 

"2040101 6 5.89e-6 0.225 0.0 0.0 90. 0.225 0.0 0.0 0010000 

•crdno ebt pressure tempf 

2040200 002 2.46000e5 1.0 

•crdno from to area floss rloss efvcahs 

2041101 004010000 204000000 2826.0e-6 0.1 0.1 0101000 

%crdno flowf flowg in.vel 

2041201 0.0 0.0 0.0

48
** upper plenum

*crdno name type 

2060000 in branch 

*crdno jun.no ctrlw 

2060001 2 1 

*crdno area length volume h.ang v.ang elev rgh dhyd tlpvbfe 

2060101 0.0 0.460 30.0e-3 0.0 90. 0.460 0.0 0.0 0010000 

* Total volume/37 

'2060101 0.0 0.460 0.8108e-3 0.0 90. 0.460 0.0 0.0 0010000 

*crdno ebt pressure tempf 

2060200 002 2.46000e5 1.0 

* 109 holes D=5.3mm + 12 holes D=3.5 mm 

* =2403.5 mm2+ 115.4mm2 = 2519mm2, 

2061101 204010000 206000000 2519.00e-6 0.1 0.1 0100000 

* Outlet pipe D=60 mm, A= 2826mm2 

2062101 206010000 010000000 2826.0e-6 0.1 0.1 0100000 

*crdno flowf flowg in.vel 

2061201 0.0 0.0 0.0 

2062201 0.0 0.0 0.0 ---------------

0100000 "u p" tmdpvol 

0100101 1.0e6 1. 0. 0. 90. 1. 0. 0. 10 

0100200 102 

0100201 0.0 2.46000e5 1.0 

heat slab structure * 

*crdno no.h.s no.m.p geo s.s.flg left reffi bvi no.ax.p 

10016000 15 6 2 1 0. 402 1 8 

10016100 0 1 

*crdno intvl rt.cor intvl rt.cor * 9999 

10016101 1 1.25e-3 I 3.85e-3 1 3.95e-3 2 4.55e-3 

*crdno comp intvl comp intvl 

* NIHROM MGO INCONEL 

*10011201 2 2 3 4 4 5

49

-r-r -r It -t- , . . . . . . . . . . 4- -4- 4- 4- 4ý -& -4- 4-4- 4.4- 4- -4- -1- 4. 4- 4. -1.
mgo nihrom mgo s-steel 

10016201 3 1 2 2 3 3 4 5 

10016301 0.0 1 

10016302 1.0 2 

10016303 0.0 5 

10016400 -1 

10016401 373.00 373.00 373.00 373.00 373.00 373.00 

10016402 373.00 373.00 373.00 373.00 373.00 373.00 

10016403 373.00 373.00 373.00 373.00 373.00 373.00 

10016404 373.00 373.00 373.00 373.00 373.00 373.00 

10016405 373.00 373.00 373.00 373.00 373.00 373.00 

10016406 373.00 373.00 373.00 373.00 373.00 373.00 

10016407 373.00 373.00 373.00 373.00 373.00 373.00 

10016408 373.00 373.00 373.00 373.00 373.00 373.00 

10016409 373.00 373.00 373.00 373.00 373.00 373.00 

10016410 373.00 373.00 373.00 373.00 373.00 373.00 

10016411 373.00 373.00 373.00 373.00 373.00 373.00 

10016412 373.00 373.00 373.00 373.00 373.00 373.00 

10016413 373.00 373.00 373.00 373.00 373.00 373.00 

10016414 373.00 373.00 373.00 373.00 373.00 373.00 

10016415 373.00 373.00 373.00 373.00 373.00 373.00 

10016501 0 0 0 1 9.435 1 

10016502 0 0 0 1 9.435 02 

10016503 0 0 0 1 9.435 03 

10016504 0 0 0 1 9.25 04 

10016505 0 0 0 1 9.25 05 

10016506 0 0 0 1 9.25 06 

10016507 0 0 0 1 9.25 07 

10016508 0 0 0 1 9.25 08 

10016509 0 0 0 1 9.25 09 

10016510 0 0 0 1 9.25 10 

10016511 0 0 0 19.25 11 

10016512 0 0 0 19.25 12 

10016513 0 0 0 1 9.435 13 

10016514 0 0 0 1 9.435 14 

10016515 0 0 0 1 9.435 15 

10016601 004010000 0 1 1 9.287 1 

10016602 004020000 0 1 1 9.287 2 

10016603 004030000 0 1 1 9.287 3 

10016604 004040000 0 1 1 9.2685 4 

10016605 004050000 0 1 1 9.2685 5 

10016606 004060000 0 1 1 9.361 6 

10016607 004070000 0 1 1 9.361 07 

10016608 004080000 0 1 1 9.361 08 

10016609 004090000 0 1 1 9.361 09 

10016610 004100000 0 1 1 9.3684 10 

10016611 004110000 0 1 1 9.3684 11 

10016612 004120000 0 1 1 9.3277 12 

10016613 004130000 0 1 1 9.3277 13 

10016614 004140000 0 1 1 9.3277 14 

10016615 004150000 0 1 1 8.769 15 

10016701 10002 0.044 0 0 1 

10016702 10004 0.044 0 0 2

50
10016703 

10016704 

10016705 

10016706 

10016707 

10016708 

10016709 

10016710 

10016711 

10016712 

10016713 

10016714 

10016715

10006 

10008 

10010 

10012 

10014 

10016 

10018 

10020 

10022 

10024 

10026 

10028 

10030

0.044 

0.0744 

0.0744 

0.11467 

0.11467 

0.11467 

0.11467 

0.07388 

0.07388 

0.0442 

0.0442 

0.0442 

0.00

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0 

0 0

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15

10016901 12.53e-3 20. 20. 0 0 0 0 1.0 15 

shroud

*crdno no.h.s 

10121000 15 

10121100 0 

*crdno intvl 

10121102 3

no.m.p geo s.s.flg left reffl bvi no.ax.p 

6 2 1 45.0-3 * 402 0 8 

1 

rt.cor 

68.3e-3

*crdno comp intvl comp intvl

* Ssteel 

10121201 11 

10121202 12 

10121301 0.0 

10121302 0.0 

10121400 -1

10121401 

10121402 

10121403 

10121404 

10121405 

10121406 

10121407 

10121408 

10121409 

10121410 

10121411 

10121412 

10121413 

10121414 

10121415 

10121501 

10121502 

10121503

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00

2 

5 * isolator

2 

5

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00

004010000 0 

004020000 0 

004030000 0

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00

1 1 0.251 

1 1 0.251 

1 1 0.251

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00 

373.00

1 

2 

3

51
10121504 004040000 0 1 1 0.2505 4 

10121505 004050000 0 1 1 0.2505 5 

10121506 004060000 0 1 1 0.253 6 

10121507 004070000 0 1 1 0.253 7 

10121508 004080000 0 1 1 0.253 8 

10121509 004090000 0 1 1 0.253 9 

10121510 004100000 0 1 1 0.2532 10 

10121511 004110000 0 1 1 0.2532 11 

10121512 004120000 0 1 1 0.2521 12 

10121513 004130000 0 1 1 0.2521 13 

10121514 004140000 0 1 1 0.2521 14 

10121515 004150000 0 1 1 0.237 15 

10121601 -700 0 3701 1 0.251 1 

10121602 -700 0 3701 1 0.251 2 

10121603 -700 0 3701 1 0.251 3 

10121604 -700 0 3701 1 0.2505 4 

10121605 -700 0 3701 1 0.2505 5 

10121606 -700 0 3701 1 0.253 6 

10121607 -700 0 3701 1 0.253 7 

10121608 -700 0 3701 1 0.253 8 

10121609 -700 0 3701 1 0.253 9 

10121610 -700 0 3701 1 0.2532 10 

10121611 -700 0 3701 1 0.2532 11 

10121612 -700 0 3701 1 0.2521 12 

10121613 -700 0 3701 1 0.2521 13 

10121614 -700 0 3701 1 0.2521 14 

10121615 -700 0 3701 1 0.237 15 

10121701 100 0.0 0 0 1 

10121702 100 0.0 0 0 2 

10121703 100 0.0 0 0 3 

10121704 100 0.0 0 0 4 

10121705 100 0.0 0 0 5 

10121706 100 0.0 0 0 6 

10121707 100 0.0 0 0 7 

10121708 100 0.0 0 0 8 

10121709 100 0.0 0 0 9 

10121710 100 0.0 0 0 10 

10121711 100 0.0 0 0 11 

10121712 100 0.0 0 0 12 

10121713 100 0.0 0 0 13 

10121714 100 0.0 0 0 14 

10121715 100 0.0 0 0 15 

10121801 3.4e-3 20. 20. 0 0 0 0 1.0 15 

10121901 3

.4e-3 20. 20. 0 0 0 0 1.0 15 

* 109 holes 

* upper plate *crdno no.h.s no.m.p geo s.s.flg left reffl bvi no.ax.p 

10122000 1 3 2 1 2.65-3 * 402 0 8

52
10122100 0 1

*crdno intvl 

10122101 2 

*10122101 2 

*crdno comp 

* Ssteel 

10122201 11 

10122301 0.0 

10122400 -1

10122401

rt.cor 

5.29e-3 * varl I * to obtain need mass of metal 

3.65e-3 * varlO 

intvl comp intvl 

2

2

373.00 373.00 373.00

10122501 204010000 0 1 1 10.9 1 *0.1*109

10122601 0 0 0 1 10.9 1 

10122701 0 0.0 0 0 1 

10122801 3.4e-3 20. 20. 0 0 0 0 1.0 1 

10122901 3.4e-3 20. 20. 0 0 0 0 1.0 1 

heat structure thermal property data *

20100200 tbl/fctn 1 

20100300 tbl/fctn 1 

20100400 tbl/fctn 1 

20101200 tbl/fctn I

I * nihrom 

1 * MG-O 

I * Steel 

I * Isolator

* thermal conductivity tables 

* ISOLATOR 

*2. 01 23.0. 1 0... 1-1-I

20101201 293.0 0.05 

20101202 2700.0 0.05 

* -------- 1------ I -- -1... I . --------- I -------- I -------- I ------- I 

* ISOLATOR 

20101251 300. 1.428e5 

20101252 2700. 5.50e6 

* NICHROME 5 THERMAL CONDUCTIVITY (W/M-K) (004) [HEATERS] 

* -..... 1-.....1-....- 1....1.... 1----------- 1 -..... 1

53
20100201 293.0 

20100202 373.0 

20100203 473.0 

20100204 573.0 

20100205 673.0 

20100206 873.0 

20100212 2700.0

12.5 

13.8 

15.6 

17.2 

19.0 

22.6 

25.0

* - I I 1 -1- -----1 ...------ 1 .----- -I 

NICHROME 5 HEAT CAPACITY (J/M3-K) 

20100251 300. 3.66e6 

20100252 400. 3.96e6 

20100253 500. 4.16e6 

20100254 600. 4.34e6 

20100255 700. 4.46e6 

20100256 800. 4.68e6 

20100257 900. 4.83e6 

20100258 1000. 5.04e6 

20100259 1100. 5.18e6 

20100260 1200. 5.30e6 

20100261 1700. 5.50e6 

20100262 2700. 5.50e6 

S .. ..1 .. .. .. 1 -. .. .. 1 .. . . .1 .-. .. .1 .. .. .. 1-. . . . 

*iMIAGN.OXIDE THERMAL CONDLCTIVITY (W/M-K) (005) [INSULATOR] * .. ..1 . . . . 1 1- .. .. . 1 .. . . .1 -. . . .1 .. .. ..1 . . . . 

20100301 293.0 1.7 

20100302 473.0 2.75 

20100303 573.0 2.6 

20100304 673.0 2.5 

20100305 873.0 2.52 

20100306 1073.0 2.90 

20100307 1173.0 3.20 

20100308 2573.0 3.2 

* -------- I -- ------ I ------- I -- ------ I ------- I -------- --1 I ----- 1 

* MAGN. OXIDE HEAT CAPACITY (J/M3-K) * --...1 .. . . .1 .... ... 1 .. . . .1 .. .. ..1 .-. .. .1-- .. ..

20100351 293. 2.87e6 

20100352 373. 3.04e6 

20100353 473. 3.15e6 

20100354 573. 3.20e6 

20100355 673. 3.24e6 

20100356 773. 3.29e6 

20100357 873. 3.34e6 

20100358 973. 3.44e6 

20100359 1073. 3.53e6 

20100360 1173. 3.63e6 

20100361 1573. 3.63e6 

20100362 2573. 3.63e6 * 1 1 .. - . .. -. ..I.. 1. .. . .1 -.. . .I . . . .

20100401 

20100402 

20100403 

20100404 

20100405 

20100406 

20100407

323.0 

373.0 

473.0 

673.0 

873.0 

1073.1 

1273.

thermal conductiviti (w/m'k) (004) 

14.9 

15.6 

17.2 

20.4 

23.7 

0 27.4 

0 31.0

54

- - -SLeel-
20100408 1573.0 31.0 

20100409 2573.0 31.0 

heat capacity (j / m**3 * k) (004)

20100451 

20100452 

20100453 

20100454 

20100455 

20100456 

20100457 

20100458 

20100459

323.0 

373.0 

473.0 

673.0 

873.0 

1073.0 

1273.0 

1573.0 

2573.0

3.763e6 

3.855e6 

4.029e6 

4.264e6 

4.680e6 

4.985e6 

5.340e6 

5.340e6 

5.340e6 - ---- ------ ------ ----- ----- ------ ----- ---- ------ ---- ------ ------ ------- -----

* s-steel 

- - - - - - - - - - - - - - -- - - - - - - - - - - - - -

20101100 tbllfctn, 1, 1 

* ----- thermal conductivity table 

20101101 2.731500e+02 1.298051e+01 

20101102 1.199817e+03 2.510604e+01 

* ----- volumetric heat capacity table 

20101151 2.850000e+02 3.453703e+06, 

20101152 3.664833e+02 3.830413e+06, 

20101153 4.775944e+02 4.099214e+06, 

20101154 5.887056e+02 4.334415e+06, 

20101155 6.998167e+02 4.502416e+06, 

20101156 1.366483e+03 5.376019e+06

3.350000e+02 

4.220389e+02 

5.331500e+02 

6.442611 e+02 

8.109278e+02

3.769201 e+06 

3.964814e+06 

4.233615e+06 

4.435081e+06 

4.636816e+06

* power table 100 *

20210000 power 0 1 

20210001 0.0 0.00 

20210002 1.0 0.13 

20210004 3.0 0.38 

20210005 4.0 0.55 

202100065.0 0.79 

20210007 7.0 1.27 

20210008 8.0 1.59 

202100099.0 1.95 

20210010 11.0 2.77 

20210011 13.0 3.81 

20210012 14.0 4.37 

20210013 16.0 5.63 

20210014 21.0 9.68 

20210015 22.0 10.66 

20210016 24.0 12.76 

20210017 25.0 13.85 

20210018 26.0 15.05 

20210019 27.0 16.27 

20210020 29.0 19.03 

20210021 30.0 20.25 

20210022 31.0 21.65 

20210023 32.0 23.2 

20210024 34.0 26.64 

20210025 35.0 27.99 

20210026 37.0 31.59 

20210027 38.0 33.44

.0 1 .0e3 * Total power * 0. 

* 

* 

* 

* 

* 

* 

* 

* 

* 

* 

* 

* 

* 

* 

* 

* 

* 

* 

*

55

A
20210028 41.0 39.44 

20210029 42.0 41.87 

20210030 45.0 48.38 

20210031 54.0 66.83 * 

20210032 60.0 75.21 * 

20210033 66.0 84.00 * 

20210034 67.0 85.38 * 

20210035 69.0 88.50 * 

20210036 71.0 91.85 

20210037 72.0 93.55 * 

20210038 74.0 97.08 * 

20210039 75.0 98.99 * 

20210040 77.0 102.99 * 

20210041 82.0 114.31 * 

20210042 83.0 116.92 * 

20210043 84.0 119.56 * 

20210044 88.0 131.4 

20210045 89.0 134.58 * 

2021004690.0 137.22 * 

20210047 94.0 148.15 * 

20210048 95.0 148.16 * 

20210049 98.0 148.08 * 

20210050 99.0 148.07 * 

20210051 100.0 147.9 * 

20210052 101.0 148. * 

20210053 102.0 147.8 * 

20210054 124.0 147.85 * 

20210055 125.0 147.64 * 

20210056 126.0 147.80 * 

20210057 129.0 147.91 * 

20210058 130.0 147.72 * 

20210059 131.0 146.48 * 

20210060 132.0 143.31 * 

20210061 133.0 141.95 * 

20210062 134.0 141.37 * 

20210063 135.0 140.56 * 

20210064 142.0 135.15 * 

20210065 143.0 134.60 * 

20210066 144.0 133.56 * 

20210067 145.0 133.74 * 

20210068 150.0 130.56 * 

20210069 151.0 130.68 * 

20210070 157.0 127.97 * 

20210071 170.0 122.89 * 

20210072 180.0 119.68 * 

20210073 251.0 105.9 

20210074 270.0 103.61 

20210075 290.0 101.32 

20210076 320.0 98.01 

20210077 340.0 96.68 

20210078 350.0 95.72 

CONTROL VARIABLES 

20507100 lev4 sum 1.0 0.0 0 

20507101 0.0 0.243 voidf 004010000 

20507102 0.255 voidf 004020000 

20507103 0.278 voidf 004030000 

20507104 0.232 voidf 004040000 

20507105 0.268 voidf 004050000 

20507106 0.254 voidf 004060000

56
20507107 

20507108 

20507109 

20507110 

20507111 

20507112 

20507113 

20507114 

20507115

0.255 

0.255 

0.248 

0.322 

0.182 

0.272 

0.255 

0.231 

0.237

20507200 flfl mu 

20507201 rhofj 

20507202 velfj 

20507203 voidfj 

20507300 tlti mu 

20507301 rhofj 

20507302 velfj 

20507303 voidfj 

* I 1 ---- ----22 

20507400 fig mu 

20507401 rhogj 

20507402 velgj

20507403 

20507500 

20507500 

20507501 

20507502 

20507600 

20507601 

20507602 

20507700 

20507701 

20507702 

20507800 

20507801 

20507802 

20507900 

20507901 

20507902 

20508000 

20508001 

20508100 

20508101 

20508200 

20508201

voidgj 

---. .--- 2-

voidf 

voidf 

voidf 

voidf 

voidf 

voidf 

voidf 

voidf 

voidf

004070000 

004080000 

004090000 

004100000 

004110000 

004120000 

004130000 

004140000 

004150000

Itt 2438.0e-6 0.0 0 

204010000 

204010000 

204010000

It 3328.0e-6 

006010000 

006010000 

006010000

0.0 0

3 ----.-.- 4 ----.... 5 ----. ---- 6 ----.. . 7

It 2438.0e-6 0.0 0 

204010000 

204010000 

204010000

dpi sum 1.Oe 

0.0 1. 

-1.0 p

dp2 sum 

0.0 1. 

-1.0 

dp3 sum 

0.0 1. 

-1.0 

dp4 sum 

0.0 1. 

-1.0 

dp5 sum 

0.0 1. 

-1.0

1.Oe 

1.0e 

1.0e 

1 .0e

-3 .... .... 4 ----.. . . 5 .... .. 6 .... .... 7. 7 

-3 0.0 0 

p 004010000 

004150000 

-3 0.0 0 

p 004080000 

04150000 

-3 0.0 0 

p 004010000 

p 004080000 

--3 0.0 0 

p 006010000 

p 004010000 

e-3 0.0 0 

p 204010000 

p 206010000

inflow integral 1.0 0.0 0 

cntrlvar 73 

oflowf integral 1.0 0.0 0 

cntrlvar 72 

oflowg integral 1.0 0.0 0 

cntrlvar 74

57
* Core heat 

*crd no name type scale init flag 

20508300 h core sum 1.0 0.0 

1

*crd no 

20508301 

20508302 

20508303 

20508304 

20508305 

20508306 

20508307 

20508308 

20508309 

20508310 

20508311 

20508312 

20508313 

20508314 

20508315 

* 

-

-

-

-

-

-

aO a] 

0.0 1.0 

1.0 

1.0 

1.0 

1.0 

1.0 

1.0 

1.0 

1.0 

1.0 

1.0 

1.0 

1.0 

1.0 

1.0

var 

q 

q 

q 

q 

q 

q 

q 

q 

q 

q 

q 

q 

q 

q q

code 

004010000 

004020000 

004030000 

004040000 

004050000 

004060000 

004070000 

004080000 

004090000 

004100000 

004110000 

004120000 

004130000 

004140000 

004150000

*

Core heat calculated from cntrlvar

name type scale init 

h core sum 1.0 0.0 

aO al var code 

0.0 0.04433 cntrlvar 2 

0.04433 cntrlvar 4 

0.04433 cntrlvar 6 

0.1065 cntrlvar 8 

0.1065 cntrlvar 10 

0.07975 cntrlvar 12 

0.07975 cntrlvar 14 

0.07975 cntrlvar 16 

0.07975 cntrlvar 18

0.103 

0.103 

0.043 

0.043 

0.043

mass4 sum 

0.0 0.251 

0.251 

0.251 

0.2505 

0.2505 

0.253 

0.253 

0.253 

0.253 

0.2532 

0.2532 

0.2521 

0.2521 

0.2521 

0.237

cntrlvar 20 

cntrlvar 22 

cntrlvar 24 

cntrlvar 26 

cntrlvar 28

2438.0e-6 

rho 

rho 

rho 

rho 

rho 

rho 

rho 

rho 

rho 

rho 

rho 

rho 

rho 

rho 

rho

0.0 1 0 

004010000 

004020000 

004030000 

004040000 

004050000 

004060000 

004070000 

004080000 

004090000 

004100000 

004110000 

004120000 

004130000 

004140000 

004150000

*crd no flag

20508400 

*crd no 

20508401 

20508402 

20508403 

20508404 

20508405 

20508406 

20508407 

20508408 

20508409 

20508410 

20508411 

20508412 

20508413 

20508414 

20505700 

20505701 

20505702 

20505703 

20505704 

20505705 

20505706 

20505707 

20505708 

2051)5709 

20505710 

20505711 

2050)5712 

20505713 

2050)5714 

20505715

58
--- --- I .... ..-- .2 ----. .... 3 ----. .... 4 ----. .... 5 ----. .... 6 ----. .... 7 

20500100 heatl function 1.0 1.0 1 

cccgOnn no table 

20500101 htvat 0016001 036 

20500200 heat2 mult 1.0 1.0 1 

no table 

20500201 cntrlvar 1 cntrlvar 41 

20500300 heatl function 1.0 1.0 1 

cccgOnn no table 

20500301 htvat 0016002 036 

------------

20500400 heat2 mult 1.0 1.0 1 

no table 

20500401 cntrlvar 003 cntrlvar 41 

20500500 heat] function 1.0 1.0 1 

* cccgOnn no table 

20500501 htvat 0016003 036 

------------

20500600 heat2 mult 1.0 1.0 1 

no table 

20500601 cntrlvar 005 cntrlvar 41 

20500700 heatl function 1.0 1.0 1 

cccgOnn no table 

20500701 htvat 0016004 036 

20500800 heat2 mult 1.0 1.0 1 

no table 

20500801 cntrlvar 007 cntrlvar 41 

20500900 heatl function 1.0 1.0 1 

* cccgOnn no table 

20500901 htvat 0016005 036 

------- - ---------

20501000 heat2 mult 1.0 1.0 1

59
no table 

20501001 cntrlvar 009 cntrlvar 41 

20501100 heatd function 1.0 1.0 1 

cccgOnn no table 

20501101 htvat 0016006 036 

20501200 heat2 mult 1.0 1.0 1 

no table 

20501201 cntrlvar 011 cntrlvar 41 

205013(X) heatl function 1.0 1.0 1 

cccgOnn no table 

20501301 htvat 0016007 036 

20501400 heat2 mult 1.0 1.0 I 

no table 

20501401 cntrlvar 013 cntrlvar 41 

20501500 heat] function 1.0 1.0 1 

* cccg,-nn no table 

20501501 htvat 0016008 036 

20501600 heat2 mult 1.0 1.0 1 

no table 

20501601 cntrlvar 015 cntrlvar 41 

20501700 heat] function 1.0 1.0 1 

cccgOnn no table 

20501701 htvat 0016009 036 

20501800 heat2 mult 1.0 1.0 1 

no table 

20501801 cntrlvar 017 cntrlvar41 

20501900 heatl function 1.0 1.0 1

60
* cccgOnn no table 

20501901 htvat 0016010 036 

20502000 heat2 mult 1.0 1.0 1 

* no table 

20502001 cntrlvar 019 cntrlvar41 

* . . . . . . . . . . . . . . . . . . . . . . . . . . . 

20502100 heatl function 1.0 1.0 1 

cccgOnn no table 

20502101 htvat 0016011 036 

20502200 heat2 mult 1.0 1.0 1 

no table 

20502201 cntrlvar 21 cntrlvar 41 

20502300 heatl function 1.0 1.0 1 

* cccgOnn no table 

20502301 htvat 0016012 036 

20502400 heat2 mult 1.0 1.0 1 

* no table 

20502401 cntrlvar 023 cntrlvar 41 

20502500 heatl function 1.0 1.0 1 

* cccgOnn no table 

20502501 htvat 0016013 036 

20502600 heat2 mult 1.0 1.0 1 

no table 

20502601 cntrlvar 025 cntrlvar 41 

20502700 head function 1.0 1.0 1 

*c cccgOnn no table 

20502701 htvat 0016014 036 

20502800 heat2 mult 1.0 1.0 1 

* no table 

20502801 cntrlvar 027 cntrlvar 41

61
20502900 heatl function 1.0 1.0 1

cccg0nn no table 

20502901 htvat 0016015 036 

20503000 heat2 mutt 1.0 1.0

20503001 

20504100 

20504100

no table 

cntrlvar 029 cntrlvar 41 

heat function 1.0 1297.3 1 

scale ini value flag 

heat function 1.0 3.902e3

* no table 

20504101 time 00

I -- Qmax/Kz*1ll.77/1.601*3.53

100

20203600 reac-t

20203601 

20203602 

20203603 

20203604 

20203605 

20203606 

20203607 

20203608 

20203609 

20203610 

20203611

293.0 

373.0 

473.0 

573.0 

673.0 

773.0 

873.0 

973.0 

1073.0 

1273.0 

1473.0

1.0 

1.0088 

1.0177 

1.0177 

1.035 

1.035 

1.035 

1.027 

1.0177 

1.0177 

1.035

20504200 heat function 1.0 6.739e2 1 

20504200 heat function 1.0 3.902e3 I

no table 

20504201 time 0 100

20504300 R function 0.1407 0.1407 1 

20504301 time 0 36 

20504400 R2 mult 1.0 0.00648 1 

20504401 cntrlvar 43 cntrlvar 43 

20504500 heatt function 1.0 1297.3 1 

20504501 time 0 100 

- - - - - - - - - - - - - -

62

I
20530100 TI sum 1.0 0.0 0 

20530101 0.0 1. httemp 001600106 

20530102 -1.0 cntrlvar 233 

20530200 T2 sum 1.0 0.0 0 

20530201 0.0 1. httemp 001600206 

20530202 -1.0 cntrlvar 233 

20530300 T3 sum 1.0 0.0 0 

20530301 0.0 1. httemp 001600306 

20530302 -1.0 cntrlvar 233 

20530400 T4 sum 1.0 0.0 0 

20530401 0.0 1. httemp 001600406 

20530402 -1.0 cntrlvar 233 

20530500 T5 sum 1.0 0.0 0 

20530501 0.0 1. httemp 001600506 

20530502 -1.0 cntrlvar 233 

k 

20530600 T6 sum 1.0 0.0 0 

20530601 0.0 1. httemp 001600606 

20530602 -1.0 cntrlvar 233 

20530700 T7 sum 1.0 0.0 0 

20530701 0.0 1. httemp 001600706 

20530702 -1.0 cntrlvar 233 

20530800 T8 sum 1.0 0.0 0 

20530801 0.0 1. httemp 001600806 

20530802 -1.0 cntrlvar 233 

20530900 T9 sum 1.0 0.0 0 

20530901 0.0 1. httemp 001600906 

20530902 -1.0 cntrlvar 233 

20531000 TIO sum 1.0 0.0 0 

20531001 0.0 1. httemp 001601006 

20531002 -1.0 cntrlvar 233 

20531100 TI1 sum 1.0 0.0 0 

20531101 0.0 1. httemp 001601106 

20531102 -1.0 cntrlvar 233 

20531200 T12sum 1.0 0.0 0 

20531201 0.0 1. httemp 001601206 

20531202 -1.0 cntrlvar 233

63
20531300 

20531301 

20531302 

20511400 

2053 1401 

20511402 

20531500 

20531501 

20531502

T13 sum 

0.0 1. 

-1.0 

T14 sum 

0.0 1. 

-1.0 

T15 sum 

0.0 1. 

-1.0

1.0 0.0 0 

httemp 001601306 

cntrlvar 233 

1.0 0.0 0 

httemp 001601406 

cntrlvar 233 

1.0 0.0 0 

httemp 001601506 

cntrlvar 233

**** Vessel wall*********** 

20520100 TKI sum 1.0 0.0 0 

20520101 0.0 1. httemp 012 100402 *zo 

20520102 -1.0 cntrlvar 233 

20520200 TK2 sum 1.0 0.0 0 

20520201 0.0 1. httemp 012100402 *zon 

20520202 -1.0 cntrlvar 233 

20520300 TK3 sum 1.0 0.0 0 

20520301 0.0 1. httemp 012 100402 *zoI 

20520302 -1.0 cntrlvar 233 

20520400 TK4 sum 1.0 0.0 0 

20520401 0.0 1. httemp 012100902 * zo 

20520402 -1.0 cntrlvar 233 

20520500 TK5 sum 1.0 0.0 0 

20520501 0.0 1. httemp 012100902 *zo 

20520502 -1.0 cntrlvar 233 

20520600 TK6 sum 1.0 0.0 0 

20520601 0.0 1. httemp 012100902 *zon 

20520602 -1.0 cntrlvar 233 

20520700 TK7 sum 1.0 0.0 0 

20520701 0.0 1. httemp 012101102"* zo 

20520702 -1.0 cntrlvar 233 

20520800 TK8 sum 1.0 0.0 0 

20520801 0.0 1. httemp 012101102 *zC 

20520802 -1.0 cntrlvar 233

20520900 

20520901 

20520902

TK9 sum 

0.0 1. 

-1.0

ne I 

el 

ne 2 

ne 2

ne 2 

e 2

ne 3

ne 3

1.0 0.0 0 

httemp 012101102 * zone 3 

cntrlvar 233

64
20521000 

20521001 

20521002

TK1Osum 1.0 0.0 0 

0.0 1. httemp 012101402 *zone 4 

-1.0 cntrlvar 233

20521100 TKII sum 1.0 0.0 0 

20521101 0.0 1. httemp 0 12 101402 *zone4 

20521102 -1.0 cntrlvar 233 

20521200 TKI2 sum 1.0 0.0 0 

20521201 0.0 1. httemp 012101402 *zone 4 

20521202 -1.0 cntrlvar 233 

• Isolation 

20521300 Tizl sum 1.0 0.0 0 

20521301 0.0 1. httemp 012100406 

20521302 -1.0 cntrlvar 233 

20521400 Tiz2 sum 1.0 0.0 0 

20521401 0.0 1. httemp 012100906 

20521402 -1.0 cntrlvar 233 

20521500 Tiz3 sum 1.0 0.0 0 

20521501 0.0 1. httemp 012101106 

20521502 -1.0 cntrlvar 233 

20521600 Tiz4 sum 1.0 0.0 0 

20521601 0.0 1. httemp 012101506 

20521602 -1.0 cntrlvar 233 

20522000 Tin sum 1.0 0.0 0 

20522001 0.0 1. tempf 006010000 

20522002 -1.0 cntrlvar 233 

20522100 Tout sum 1.0 0.0 0 

20522101 0.0 1. tempg 206010000 

20522102 -1.0 cntrlvar 233

20522200 Gin sum 133200. 0.0 0 * *37 

20522201 0.0 1. mflowj 006010000 

20522300 G__gout sum 133200. 0.0 0 

20522301 0.0 1. cntrlvar 74 

20522400 POWER sum 0.037 0.0 0 

20522401 0.0 1. cntrlvar 41 

20522500 PIN sum 1.0e-3 0.0 0 

20522501 0.0 1. p 006010000

** 37 rod,KWT

65
20522600 

20522601 

20522700

Pout sum I.Oe-3 0.0 0 

0.0 1. p 206010000 

mmmm sum 1.0 0.0 0

20522701 0.0 1. 

20522800 Tgl sur 

20522801 0.0 1. 

20522802 -1.0 

20522900 Tg2 sur 

20522901 0.0 1. 

20522902 -1.0

20523000 

20523001 

20523002 

20523100 

20523101 

20523102 

20523200 

20523201 

20523202 

20270000 

20270001 

20270002 

20270100 

20270101 

20270102

n 

n

Tg3 sum 

0.0 1. 

-1.0 

Tg4 sum 

0.0 1. 

-1.0 

TgO sum 

0.0 1. 

-1.0

mflowj 006010000 

1.0 0.0 0 *H=762 

tempg 004040000 

cntrlvar 233 

1.0 0.0 0 *H=1527 

tempg 004070000 

cntrlvar 233 

1.0 0.0 0 *H= 2037 

tempg 004090000 

cntrlvar 233 

1.0 0.0 0 *H= 2802 

tempg 004120000 

cntrlvar 233 

1.0 0.0 0 *H= 3567 

tempg 004150000 

cntrlvar 233

emperature in containment 

temp 

0.0 310.0 

1.0e6 310.0 

htc-t 0 1.0 1.0 

-1.0 300.0 

10000.0 300.0

'crdno name c.c.typ s.fac in.v. in.flag 

20523300 TCEL function 1.0 1.0 0 

*crdno var code table 

20523301 time 0 584 

20258400 reac-t 

20258401 0.0 273.0 

. end of problem

66
NRC FORM 335 U.S. NUCLEAR REGULATORY COMMISSION 1. REPORT NUMBER 

(2-89) (Assigned by NRC, Add Vol., Supp., Rev., 

NRCM 1102. BIBLIOGRAPHIC DATA SHEET and Addendum Numbers, if any.) 

3201. 3202 

(See instructions on the reverse) 

2. TITLE AND SUBTITLE NUREG/IA-0207 

RELAP5/MOD3.2.2 GAMMA ASSESSMENT FOR DOWN TO TOP REFLOODING PROCESS 

AT VVER LIKE 37-ROD BUNDLE 3 DATE REPORT PUBLISHED 

%Ar.NTH YEAR 

July 2002 

4. FIN OR GRANT NUMBER 

5. AUTHOR(S) 6. TYP-E OF REPORT 

A.S. Devkin technical 

7. PERIOD COVERED (Inclusive Dates) 

8. PERFORMING ORGANIZATION - NAME AND ADDRESS (If NRC, provide Division. Office or Region, U.S. Nuclear Regulatory Commission, and mailing address, if contractor. 

provide name and mailing address.) 

Nuclear Safety Institute 

Russian Research Center 

"Kurchatov Institute" 

123182, Moscow ,Russia

9. SPONSORING ORGANIZATION - NAME AND ADDRESS (If NRC, type "Same as above'. if contractor, provide NRC Division. Office or Region, U.S. Nuclear Regulatory Commission, 

and mailing address.) 

Division of System Analysis and Regulatory Effectiveness 

Office of Nuclear Regulatory Research 

U. S. Nuclear Regulatory Commission 

Washington, DC 20555-0001

10. SUPPLEMENTARY NOTES 

This is a Russian CAMP in-kind contribution

11. ABSTRACT (200 words or less)

The assessment of RELAP5/MOD3.2.2 Gamma for down to top reflooding at VVER like 37-rod bundle is presented. The 

experiment have been performed at IPPE test facility at the following parameters: upper plenum pressure- 0,246 MPa, cooling 

water temperature- 51 N, water velocity- 4.91 smns, average linear heat flux density at maximal heat production zone before 

water supply-1,77 kWt/m. RELAP5/MOD3.2.2Gamma assessment showed that code gives satisfactory results for all 

parameters behavior. The main discrepancies were get for cladding temperature b ehavior at level H-2.7m, where the 

calculated cladding temperatures exceed experimental data approximately on 75 K. Computed quenching time for this level 

are much higher experimental ones. For other levels accordance between experime ntal and RELAP data is rather good.

12. KEY WORDS/DESCRIPTORS (List words orpphrases that will assist researchers in locating the report) 13. AVAILABILITY STATEMENT 

unlimited 

reflood, RELAPE, VVER 14 SECURITY CLASSIFICATION 

(This Page) 

unclassified 

(This Report) 

unclassified 

15. NUMBER OF PAGES 

16. PRICE

NRC FORM 335 This form was electronically produced by Elite Federal Forms, Inc. (2-89)
(orinted 

on recycled• 

paper 

Federal Recycling Program
NUREG/IA-0207 REIAP5/MOI)3.2.2 GAMMA ASSESSMENT FOR DOWN TO TOP REFLOODING 

PROCESS AT VVER LIKE 37-ROD BUNDLE

UNITED STATES 

NUCLEAR REGULATORY COMMISSION 

WASHINGTON, DC 20555-0001 

OFFICIAL BUSINESS 

PENALTY FOR PRIVATE USE, $300

JIUIY 2002