NUREG/IA-0201

International 

Agreement Report 

Description and RELAP5 Assessment 

of the PMK-2 CAMP-CLB Experiment 

2% Cold Leg Break Without HPIS With 

Secondary Bleed 

Prepared by 

L. Perneczky, G. Baranyai, A. Guba, Gy. Ezs61, I. T6th 

KFKI Atomic Energy Research Institute 

P.O. Box 49 

H-1525 Budapest, Hungary 

Office of Nuclear Regulatory Research 

U.S. Nuclear Regulatory Commission 

Washington, DC 20555-0001 

March 2001 

Prepared as part of 

The Agreement on Research Participation and Technical Exchange 

under the International Code Application and Maintenance Program (CAMP) 

Published by 

U.S. Nuclear Regulatory Commission
AVAILABILITY OF REFERENCE MATERIALS 

IN NRC PUBLICATIONS

NRC Reference Material 

As of November 1999, you may electronically access 

NUREG-series publications and other NRC records at 

NRC's Public Electronic Reading Room at 

www.nrc.gov/NRC/ADAMS/index.html. 

Publicly released records include, to name a few, 

N U REG-series publications; Federal Register notices; 

applicant, licensee, and vendor documents and 

correspondence; NRC correspondence and internal 

memoranda; bulletins and information notices; 

inspection and investigative reports; licensee event 

reports; and Commission papers and their 

attachments. 

NRC publications in the NUREG series, NRC 

regulations, and Title 10, Energy, in the Code of 

Federal Regulations may also be purchased from one 

of these two sources. 

1. The Superintendent of Documents 

U.S. Government Printing Office 

Mail Stop SSOP 

Washington, DC 20402-0001 

Internet: bookstore.gpo.gov 

Telephone: 202-512-1800 

Fax: 202-512-2250 

2. The National Technical Information Service 

Springfield, VA 22161-0002 

www.ntis.gov 

1-800-553-6847 or, locally, 703-605-6000 

A single copy of each NRC draft report for comment is 

available free, to the extent of supply, upon written 

request as follows: 

Address: Office of the Chief Information Officer, 

Reproduction and Distribution 

Services Section 

U.S. Nuclear Regulatory Commission 

Washington, DC 20555-0001 

E-mail: DISTRIBUTION @nrc.gov 

Facsimile: 301-415-2289 

Some publications in the NUREG series that are posted at NRC's Web site address 

www.nrc.gov/NRC/NUREGS/indexnum.html 

are updated periodically and may differ from the last 

printed version. Although references to material found 

on a Web site bear the date the material was accessed, the material available on the date cited may 

subsequently be removed from the site.

Non-NRC Reference Material 

Documents available from public and special technical 

libraries include all open literature items, such as 

books, journal articles, and transactions, Federal 

Register notices, Federal and State legislation, and 

congressional reports. Such documents as theses, 

dissertations, foreign reports and translations, and 

non-NRC conference proceedings may be purchased 

from their sponsoring organization. 

Copies of industry codes and standards used in a 

substantive manner in the NRC regulatory process are 

maintained at

The NRC Technical Library 

Two White Flint North 

11545 Rockville Pike 

Rockville, MD 20852-2738 

These standards are available in the library for 

reference use by the public. Codes and standards are 

usually copyrighted and may be purchased from the 

originating organization or, if they are American 

National Standards, from

American National Standards Institute 

11 West 42nd Street 

New York, NY 10036-8002 

www.ansi.org 

212-642-4900

Legally binding regulatory requirements are stated 

only in laws; NRC regulations; licenses, including 

technical specifications; or orders, not in 

NUREG-series publications. The views expressed 

in contractor-prepared publications in this series 

are not necessarily those of the NRC. 

The NUREG series comprises (1) technical and 

administrative reports and books prepared by the 

staff (NUREG-XXXX) or agency contractors 

(NUREG/CR-XXXX), (2) proceedings of 

conferences (NUREG/CP-XXXX), (3) reports 

resulting from international agreements 

(NUREG/IA-XXXX), (4) brochures 

(NUREG/BR-XXXX), and (5) compilations of legal 

decisions and orders of the Commission and 

Atomic and Safety Licensing Boards and of 

Directors' decisions under Section 2.206 of NRC's 

regulations (NUREG-0750).

DISCLAIMER: This report was prepared under an international cooperative agreement for the exchange of 

technical information. Neither the U.S. Government nor any agency thereof, nor any employee, makes any 

warranty, expressed or implied, or assumes any legal liability or responsibility for any third party's use, or the 

results of such use, of any information, apparatus, product or process disclosed in this publication, or represents 

that its use by such third party would not infringe privately owned rights.
NUREG/IA-0201

International 

Agreement Report 

Description and RELAP5 Assessment 

of the PMK-2 CAMP-CLB Experiment 

2% Cold Leg Break Without HPIS With 

Secondary Bleed 

Prepared by 

L. Pemeczky, G. Baranyai, A. Guba, Gy. Ezs6l, I. T6th 

KFKI Atomic Energy Research Institute 

P.O. Box 49 

H-1525 Budapest, Hungary 

Office of Nuclear Regulatory Research 

U.S. Nuclear Regulatory Commission 

Washington, DC 20555-0001 

March 2001 

Prepared as part of 

The Agreement on Research Participation and Technical Exchange 

under the International Code Application and Maintenance Program (CAMP) 

Published by 

U.S. Nuclear Regulatory Commission
Description and RELAP5 Assessment 

of the PMK-2 CAMP-CLB Experiment 

ABSTRACT 

There is a general interest to validate best estimate (BE) reactor safety system codes for VVER

type reactors. The OECD-VVER code validation matrix is Used for the selection of tests in 

support of accident management (AM) and to eliminate "white spots" in the matrix. Based on 

this matrix - test types not yet covered - a proposal was made at the 12th (Spring '98) CAMP 

meeting in Ankara: 

"* perform VVER-440/213 related experiment on the Hungarian PMK-2 test facility 

"* validate RELAP5/mod 3.2 code. 

The CAMP-CLB test is an AM-type experiment with small leak in the primary coolant system 

needing secondary side heat removal. The break size is 2 %, heat removed by break is 

insufficient to depressurise primary circuit below secondary pressure. Steam dump valve to 

atmosphere regulates secondary pressure until - as an AM action - secondary bleed is started 

following core fuel rod simulator overheating which is a consequence of unavailability of the 

high pressure injection systems. 

Report presents a short description of the PMK-2 facility, the initial and boundary conditions of 

the test followed by an evaluation of the results by measured parameters. After reviewing 

modelling aspects and results of post-test calculations by RELAP5/mod3.2.2Gamma a sensitivity 

study is described. The "bifurcation type" behaviour encountered in parametric studies could be 

the result of the code calculating by different constitutional models depending on the time step or 

secondary heat losses. This behaviour needs further investigation and it is reported as a new 

RELAP5 User Problem.

CAMPNRC.DOC

KFKI AEKI CAMP

.i°
CONTENTS 

ABSTRA CT ........................................ 

1. INTRODUCTION ................................ 

2. THE PMK-2 TEST FACILITY ....................... 

2.1 System components description ................... 

2.2 Basic instrumentation and specific data to the test .....

3. TEST DEFINITION AND OBJECTIVES ... 

4. TEST DESCRIPTION ................... 

4.1 Initial conditions .................... 

4.2 Boundary conditions ................. 

4.3 Sequence of major events ............. 

4.4 Results of the test .................... 

4.5 Reproducibility of the test ............. 

5. EVALUATION OF TEST RESULTS ....... 

6. POST TEST ANALYSIS ................ 

6.1 Modelling aspects of RELAP5 analyses .. 

6.2 Initial and boundary conditions ......... 

6.3 Run parameters and critical flow options . 

6.4 Sequence of major events ............. 

7. SENSITIVITY CALCULATIONS ......... 

7.1 Study on the Maximum Time Step ...... 

7.2 Study on the SG Heat Losses ........... 

7.3 Study on discharge coefficient .......... 

8. CONCLUSIONS ....................... 

9. REFERENCES ........................ 

APPENDIX 1 ........................... 

APPENDIX 2 ............................

V

S. ... iii 

.2 

.... 15 

.... 21 .... 22 

.... 22 

S.... 22 

S.... 23 

.... 23 

.... 23 

.... 24 

.... 26 

S.... S.... 26 27 

*.... 27 

.... 28 

.... S.... 28 28 

S .... 28 

.... 29 

S.... 30 

S . . . . 3 1 

.... 32 

.... 68

........... 

..... o..... 

........... 

.... °...... 

........... 

.... °...... 

........... 

........... 

.. .. .. .. .. .° 

........... 

........... 

...... o.... 

........ °°..
LIST OF TABLES 

PMK-2 Test Facility Characteristics .................. 

V alve description ................................. 

Data of the measurement transducers .................. 

Initial steady state conditions of the test and the calculation 

Boundary conditions of the test and the calculation ....... 

Measured and calculated sequence of major events ....... 

Some details of the nodalisation ...................... 

LIST OF FIGURES

Fig. 

Fig.

2.1 Flow diagram of PMK-2 test facility ....... 

2.2 Break flow unit (length of orifice is 15 mm) .

Fig. 2.3 19-rod bundle

Fig. 2.4 Horizontal steam generator ............ 

Fig. 2.5 Steam generator pipeworks ........... 

Fig. 2.6 Upper head ........................ 

Fig. 2.7 Hot leg with pressuriser surge line ...... 

Fig. 2.8 External downcomer ................. 

Fig. 2.9 Pressuriser ......................... 

Fig. 2.10 Elevation diagram ............... '.. 

Fig. 2.11 Measurement locations (1) ........... 

Fig. 2.12 Measurement locations (2) .......... 

Fig. 2.13 Measurement locations (3) ........... 

Fig. 6 Standard PMK-2 nodalisation .........

A PPEN D IX 1 ............................................ 

Figs. 4.1-4.30 Measured parameters .......................... 

Figs. 4. lz-4.30z Measured parameters in zoomed graphs ........... 

Figs. 4.31-4.37 Measured parameters local void probe measurements 

Figs. 4.38-4.40 Comparison plots for two experiments ............ 

APPEN D IX 2 ............................................ 

Figs. 6.1-6.20 Comparison figures ............................ 

Figs. 7.1-7.22 Results of sensitivity calculations .................

•. . . . . . . . . . . . . . . . . . . . . . . !, . . . . . . . . 4 

•. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

........ 10 

........ 11 

........ 12 

........ 13 

........ 14 

........ 20 

........ 20 

........ 2 1 

........ 27

.... 32 

.... 33 

.... 33 

.... 63 

.... 66 

.... 68 

.... 69 

.... 79

vi

Table 2.1 

Table 2.2 

Table 2.3 

Table 4.1 

Table 4.2 

Table 4.3 

Table 6.1

..... 16 

..... 22 

..... 22 

..... 23 

..... 26

. . . . . . . . . . . . . . .• • •.. . • .. • • •. .. . . . . . . .. . .. 

• . . . . . °.. . . . . . . . . . . . .° . . . . . . 

.. °.....................°... 

...... °°.................. 

•. . .° . . . . .÷ . . . . . . . . . . . . . . .. °.. 

. . . °.. . . . . . . . . . . . . .. . . °. .. . . 

S. . . . . ,. .. . . . . . . . . . . . . . . . . . . 

. . . .•...°° . .. . ° • • °. . .. . . . . . . . . . . . 

°. .. . . . . . . . .. . . . . .. . . . . . . . .
1. INTRODUCTION 

There is a general interest to validate best estimate (BE) reactor safety system codes for VVERs. 

As it was reported in Refs. [1] and [2] the OECD-VVER code validation matrix is used for the 

selection of tests in support of accident management (AM) and to eliminate "white spots" in the 

matrix. Based on this matrix - test types not yet covered - a proposal was made at the 12th (Spring 

'98) CAMP meeting in Ankara: 

"* perform VVER-440/213 related experiment on the Hungarian PMK-2 test facility 

"* validate RELAP5/mod 3.x code 

as an in-kind contribution of Hungary. 

The proposed time table was: 

"* Test definition and pre-test analysis: October 1998 

"* Experiment execution: October 1999 

"* Post-test analysis with RELAP5/mod3.2.2: October 2000 

The CAMP-CLB test is an AM-type experiment with the main features (as specified at the Fall 

'98 CAMP meeting [10]) as follows: 

"* small leak in the primary coolant system needing secondary side heat removal; 

"* break size: 2 % (nozzle diameter = 1.3 mm), heat removed by break should be 

insufficient to depressurise primary circuit below secondary pressure; 

"* unavailability of high pressure injection systems (HPIS); 

"* two of four hydroaccumulators (HA) are available, both injecting to the downcomer; 

"* secondary coolant system (steam lines and feed water) is isolated, 

"* steam dump valve to atmosphere (labelled BRU-A) regulates secondary pressure 

"* HA starts to inject at 6 MPa and stops, when primary pressure stagnates 

"* HA injection cannot compensate coolant loss: hot and cold leg loop seals clear and 

core uncovers 

"* as an AM action secondary bleed is started following rod overheating 

"* steam dump valve is used for bleed 

"* HA injection induced by secondary depressurisation assures reflood of the core 

In Section 2 a short description of the PMK-2 facility is provided to help the understanding of the 

test results. 

In Section 3 a definition of the test is given to outline the most important features of the test. In 

the other part of this Section the objectives of the test are shortly described. 

Section 4 specifies the initial and boundary conditions of the test followed by an analysis of the 

results in Section 5. 

Section 6 presents modelling aspects and results of post-test calculations by RELAP5/mod3.2.2. 

The sensitivity studies being described in Section 7. 

The main conclusions are presented in Section 8.

KFKI AEKI CAMP

CAMPNRC.DOC I
2. THE PMK-2 TEST FACILITY 

The Paks Nuclear Power Plant is equipped with four VVER-440/213-type reactors. Such plants 

are slightly different from PWRs of usual design and have a number of special features, viz.: 6

loop primary circuit, horizontal steam generators (SG), loop seal in hot and cold legs, set-point 

pressure of hydroaccumulators (HA) higher than secondary pressure, the coolant from HAs is 

directly injected to the upper plenum and downcomer, etc. As a consequence of the differences 

the transient behaviour of such a reactor system should be different from the usual PWR system 

behaviour. 

The PMK-2 facility at the KFKI-AEKI, Budapest, is a full pressure, scaled down model of the 

primary and partly the secondary circuit of the Paks NPP [3]. The PMK-2 was primarily designed for the investigation of operational and off-normal transient processes and of small-break loss of 

coolant accidents (SBLOCA) of VVER-440/213 plants. The volume and power scaling ratios are 

1:2070. Due to the importance of gravitational forces in both single- and two-phase flow the 

elevation ratio is 1:1 except for the lower plenum and pressuriser (PRZ). The six loops of the 

plant are modelled by a single active loop. The coolant is water under the same operating conditions as in the nuclear power plant, i.e. transients can be started from nominal operating 

conditions. 

The first design of the PMK-NVH facility only modelled the primary circuit of the plant. This 

version was used until 1990. The PMK-2 facility is an upgraded version (first of all by addition 

of a controlled secondary heat removal system) extending the capability of the test loop to 

modelling transient processes initiated by secondary circuit disturbances or including accident 

sequences in support of AM procedures. 

During the 15 operational years - from May 1986 onwards with the first of four IAEA-SPE tests 

[4] - 48 different experiments, including cold and hot leg break LOCA, leakage from primary to 

secondary (PRISE), loss of flow, loss of feedwater, disturbances of natural circulation, etc. tests, 

were performed on this integral type test facility [5], [6], [7]. 

2.1 System components description 

The main characteristics of the PMK-2 facility is given in Table 2.1. The flow diagram of the 

facility is presented in Fig. 2.1, while the component layout and elevations are shown in Fig. 2.10. Table 2.2. gives the identification of valves with reference to Fig.2.1, including their the 

location, type and function. Figs. 2.2 to 2.9 show the main components of PMK-2. 

The reactor vessel model consists of the reactor model and the external annular downcomer (Fig. 2.8). The core is modelled by 19 electrically heated rods with uniform power distribution. The 

nominal initial value is given in each test. After the reactor scram the non-dimensional decay heat - time curve is modelled, while from 1000 s a constant value is used. In the core the heated 

length, spacer type and elevations, as well as the channel flow area are the same as in the Paks 

NPP (Fig. 2.3). 

CAMPNRC.DOC 2

KFKI AEKI CAMP
Cold and hot legs are volume scaled and care was taken to reproduce the correct elevations of the 

loop seals in both the cold and the hot legs. Cold and hot leg cross section areas if modelled 

according to volume scaling principles would have produced much too high pressure drops. 

Since, for practical reasons, length could not be maintained 1:1, relatively large cross sections 

were chosen for the PMK-2 loop. On the one hand this results in smaller cold and hot leg 

frictional pressure drops than in the NPP, on the other hand, however, it improves the relatively 

high surface to volume ratio of the PMK-2 pipework. As to the former effect, the small frictional 

pressure drop of the PMK-2 cold and hot legs have a negligible effect on small-break processes. 

Since, the pressure drop is increased using orifices around the loop. The upper head and the hot 

leg with pressuriser surge line are presented in Figs. 2.6 and 2.7. 

For the pressuriser the volume scaling, the water to steam volume ratio and the elevation of the 

water level is kept. For practical reasons the diameter and length ratios cannot be realised. The 

pressuriser is connected to the lower part of the hot leg as in the reference system. Electrical 

heaters are installed in the model and the provision of the spray cooling is similar to that of Paks 

NPP (Fig. 2.9). 

The main circulating pump of the PMK-2 serves to produce the nominal operating conditions 

corresponding to that of the NPP as well as to simulate the flow coast-down following pump trip 

early in the transient. In order to avoid operation of the pump in two-phase condition, it is 

accommodated in a by-pass line. Flow coast-down is modelled by closing a control valve in an 

appropriate manner and if flow rate is reduced to that of natural circulation, the valve in the by

passed cold leg part is opened while the pump line is simultaneously closed. 

The horizontal design of the VVER-440 steam generator is modelled by horizontal heat transfer 

tubes between hot and cold collectors in the primary side (Figs. 2.4 and 2.5). This horizontal 

design affects the primary circuit behaviour during a small break LOCA in quite a different way 

to the usual vertical steam generators. In the modelling the tube diameter, length and number 

were determined by the requirement of keeping the 1:2070 ratio of the product of the overall heat 

transfer coefficient and the equivalent heat transfer area. The elevations of tube rows and the 

axial surface distribution of tubes are the same as in the reference system. On the secondary side 

the water level and the steam to water volume ratios are kept. 

From the emergency core cooling systems (ECCS) the four hydroaccumulators of the Paks NPP 

are modelled by two vessels with prescribed initial and minimum (empty in the plant) coolant 

levels. They are connected to the downcomer and upper plenum similar to those of the reference 

system. The high and low pressure injection systems (HPIS and LPIS) are modelled by use of 

piston pumps. The flow rates measured during the start-up period of the Paks NPP are used to 

control this pumps.

CAMPNRC.DOC 

3

KFKI AEKI CAMP

CAMPNRC.DOC 3
KFKIAEKICAMP

Fig. 2.1 Flow diagram of PMK-2 test facility

Fig. 2.2 Break flow unit (length of orifice is 15 mm)

CAMPNRC.DOC 4

KFKI AEKI CAMP
Table 2.1 

PMK-2 Test Facility Characteristics 

Reference NPP: 

Paks Nuclear Power Plant with VVER-440/213 reactors 

1375 MWt - hexagonal fuel arrangement 

6 loops - horizontal steam generators 

General Scaling factor: 

Power, volumes: 1/2070, loop: 1/345 (1 loop representation) 

Elevations: 1/1 

Primary coolant system: 

- Pressure: 12.4 MPa (nominal), 16 MPa (max.) 

- Nominal core inlet temperature: 540K 

- Nominal core power: 664 kW 

- Nominal flow rate: 4.5 kg/s 

Special features: 

- 19 heater rods, uniform axial and radial power distribution 

- 2.5 m heated length 

- External downcomer 

- Horizontal SG heat transfer tubes 

- Pump is accommodated in by-pass line 

-- flow rate 0 to nominal value 

-- NPP pump coastdown simulation 

- Loop piping: 46 mm ID 

Secondary coolant system: 

- Pressure: 4.6 MPa 

- Feed wate? temperature: 493 K 

- Nominal steam mass flow: 0.36 kg/s 

Special features: 

- Vertical part of horizontal steam generator 

- Controlled heat removal system 

Safety injection systems: 

- HPIS 

- LPIS 

- SITs 

- Emergency feed water 

Control system: 

- Automatic control of sequences by computer 

- Control desk 

CAMPNRC.DOC 5

KFKI AEKI CAMP
KFKI AEKI

Table 2.2

Valve description

Item Identif. Position Type Function Size Comments 

No. No. * Nom.I.D. 

Fig.2.1 (mm) 

1 PV 1I Pump delivery line 1 Flow control, pump coast down 50 

(see Section 4) 

2 MV 1I Cold leg loop seal 2 Pump cost down 50 

(see Section 4) 

3 MV12 Pump suction line 2 Isolation of by-pass for pump after 100 

pump trip (see Section 4) 

4 PV 12 Pressuriser spray line 1 Control of spray cooling in pressuriser 15 Closed after transient 

initiation 

5 PV21 Feedwater line 1 Control of feedwater 15 closing time 3s 

6 PV22 Steam line 1 Control of steam 25 closing time 3s 

7 PV23 Steam generator 1 Secondary side steam relief valve 25 diameter of orifice 4 mm 

(BRU-A) opening/closing time 3 s 

8 PV31 HPIS line 1 Modelling of the HPIS system 15 

9 PV32 LPIS line 1 Modelling of the LPIS system 15 

10 MV31 Break location 2 Break valve 25 diameter of orifice 1.3 mm 

11 MV91 SIT line 2 Actuation of SIT 15 

11 MV92 SIT line 2 Actuation of SIT 15 

12 PV71 Pressuriser I Pressuriser safety valve 25 diameter of orifice 1 mm 

1 - Honeywell control valve 

2 - Motor valve from Paks NPP

CAMPNRC.DOC 6

CAMP
KFKIAEKICAMP

Thermocouple 

locations 

13 5 7 9 1113151719

Section A-A

4- 0 133/100

030 

copper

Fig. 2.3 19-rod bundle

CAMPNRC.DOC 7

0 9.1x2

6 7

KFKI AEKI CAMP
C A A,D 43LYj.J.

0 

(N

CD

0 (N

Fig. 2.4 Horizontal steam generator

CAMPNRC.DOC

8

KFKI AEKI

C 

To PV2

CN M0

AA41/D
KFKJ EKI AMP

Fig. 2.5 Steam generator pipeworks

CAMPNRC.DOC

9

KFKIAEKI C A N/I'P
KFKI AEKI

CD 

CD' 

cli3

A-A section 

see Fig.3.7 

A

0 8ýxE 

130

L

IA I =3

Fig. 2.6 Upper head

CAMPNRC.DOC 

10

8.485 m

CAMP

CDJ 

C14

A

A

r 6.395 m

ItO

6.120 m

CAMP
KFKI AEKI CAMP

Fig.2.7 Hot leg with pressuriser surge line

CAMPNRC.DOC

11

KFKI AEKI CAMP
KFKI AEKI

A-A 

046 

O 0OE 

004 

Ul) 

Fig. 2.8 External downcome~r

CAMPNRC.DOC 

12

CAMP
KFKI AEKI

7.800(m 

C0 

CAMPNRC.DOC

240 

Fig. 2.9. Pressuriser

Heater max.3.2 kW

13

I 

014x2,_ II

CAMP
KFKI~~ AEIMP

- 10

-9

-7

7-5 

"4 

-3

-1 

-0

- -1 Fig. 2.10 Elevation diagram

CAMPNRC.DOC 

14

KFKI AEKI (•AN!IP

10.2
2.2 Basic instrumentation and specific data to the test 

The basic instrumentation of the PMK-2 facility is given in the Handbook [ 3 ]. Since specific 

data are needed, some additional, specific instruments are to be installed. 

The test specific break flow unit with a break orifice of 1.3 mm diameter is presented in Fig. 2.2. 

The reference level for elevation is the bottom plate of the lower plenum. To facilitate the 

interpretation of the liquid levels a simple elevation diagram is provided in Fig. 2.10, giving the 

heights from the 0.00 m reference level. 

Coolant levels are measured by DP-type transducers, therefore the levels are collapsed levels. 

Collapsed levels in the data base are derived from the signals of the DP-type transducers, 

together with the necessary corrections, which are related to the density differences 

An important part of the instrumentation is the local void (LV) measurement system consisting 

of needle shaped conductivity probes developed at Forschungszentrum Rossendorf e. V, 

Germany. The location of the needle probes in the PMK facility is shown in Fig. 2.13. There are 

three probes in the reactor model. One of them is located near to the core outlet (LV25). The 

other probe is at the reactor outlet (LV21). The third (LV22) is placed into the top of upper 

plenum. There are four probes in the inclined section of the hot leg loop seal (LV30, LV32, 

LV35, LV34). The probes LV33 and 41 are placed at the bottom of the loop seal and at the inlet 

of the steam generator, respectively. LV51 and 52 are mounted into the cold leg loop seal. The 

LV71 is located at the bottom of pressuriser. The error of the measured value reaches maximum 

values at medium void fraction. At 0% and 100% voids the probes give always the right signal 

for water or steam. 

The location and main characteristics of the instrumentation with data of measurement 

parameters is given in Figs. 2.11 to 2.13. and in Table 2.3 where the last three columns have the 

following meanings: 

C additional constant in engineering units (for absolute and differential pressure measurements 

this value is the hydraulic head, for temperatures this is a calibration constant) 

A absolute maximum error of the measurement in % or in engineering units 

(T standard deviation of the measurement in % or in engineering units 

Identification of the measured parameters are as follows: 

Pressure : PR 

Differential pressure : DP 

Temperature : TE 

Level : LE 

Flow : FL 

Integrated flow rate : MA 

Density : DE 

Local void : LV 

Power : PW 

CAMPNRC.DOC 

15

KFKI AEKI CAMP
FKKI AEKI CAMP 

Table 2.3 Data of the measurement transducers

Identi- Location and type Elevation Unit Min. Max. C A j6 fication (in) + + 

TEl0 Heater rod surface (10), THC 1.044 K 273.15 1273.15 0.0 1.96 1.30 

TEll Heater rod surface(2), THC 1.494 K 273.15 1273.15 0.20 1.96 1.30 

TE12 Heater rod surface(8), THC 1.994 K 273.15 1273.15 0.0 1.96 1.30 

TE13 Heater rod surface(9), THC 2.494 K 273.15 1273.15 -0.20 1.96 1.30 

TE14 Heater rod surface(6), THC 2.994 K 273.15 1273.15 0.20 1.96 1.30 

TE15 Heater rod surface(11), THC 3.444 K 273.15 1273.15 -0.20 1.96 1.30 

TE16 Heater rod surface(l), THC 3.444 K 273.15 1273.15 -3.0 1.96 1.30 

TE17 Heater rod surface(16), THC 3.444 K 273.15 1273.15 -5.0 1.96 1.30 

TE18 Heater rod surface(2), THC 3.444 K 273.15 1273.15 -4.0 1.96 1.30 

TE19 Heater rod surface(3), THC 3.444 K 273.15 1273.15 -4.20 1.96 1.30 

TE22 Upper plenum temperature, PTR 4.664 K 273.15 673.15 2.20 1.67 1.16 

TE23 Wall in upper plenum, THC 6.225 K 273.15 1273.15 0.00 1.96 1.30 

TE24 Upper plenum temperature, PTR 8.315 K 273.15 673.15 0.00 1.67 1.16 

TE41 SG primary coolant inlet, PTR 5.925 K 273.15 673.15 6.1 1.67 1.16 

TE42 SG primary coolant outlet, PTR 5.925 K 273.15 673.15 9.4 1.67 1.16 

TE43 Heat transfer tube inlet 1, THC 8.163 K 273.15 1273.15 0.00 1.96 1.30 

TE44 Heat transfer tube outlet 1, THC 8.163 K 273.15 1273.15 0.00 1.96 1.30 

TE45 Heat transfer tube inlet 2, THC 7.591 K 273.15 1273.15 0.00 1.96 1.30 

TE46 Heat transfer tube outlet 2, THC 7.591 K 273.15 1273.15 0.00 1.96 1.30 

TE47 Heat transfer tube inlet 3, THC 6.385 K 273.15 1273.15 0.00 1.96 1.30 

TE48 Heat transfer tube outlet 3, THC 6.385 K 273.15 1273.15 0.00 1.96 1.30 

TE61 Coolant downcomer inlet, PTR 4.520 K 273.15 673.15 1.0 1.67 1.16 

TE62 Wall in downcomer, THC 4.995 K 273.15 1273.15 0.00 1.96 1.30 

TE63 Coolant at core inlet, PTR 0.190 K 273.15 673.15 3.0 1.67 1.16

CAMPNRC.DOC 

16
KFKI AEKI CAMP

Table 2.3 cont.

Identi- Location and type Elevation Unit Min. Max. C A 6 

fication (m) _ + 

TE70 Surge line temperature, THC 5.325 K 273.15 1273.15 +6.62 1.96 1.30 

TE80 Sec. water hot coll. 1, THC 8.163 K 273.15 1273.15 0.00 1.96 1.30 

TE81 Feedwater temperature, PTR 5.475 K 273.15 673.15 0.0 1.67 1.16 

TE82 Sec. water hot coll. 2, THC 7.591 K 273.15 1273.15 0.00 1.96 1.30 

TE84 Sec. water hot coll. 3, THC 6.385 K 273.15 1273.15 +1.52 1.96 1.30 

TE83 Sec. water middle 1, THC 8.163 K 273.15 1273.15 +4.61 1.96 1.30 

TE85 Sec. water middle 2, THC 7.591 K 273.15 1273.15 -4.61 1.96 1.30 

TE87 Sec. water middle 3, THC 6.385 K 273.15 1273.15 0.00 1.96 1.30 

TE86 Sec. water cold coll. 1, THC 8.163 K 273.15 1273.15 -3.79 1.96 1.30 

TE88 Sec. water cold coll. 2, THC 7.591 K 273.15 1273.15 -2.81 1.96 1.30 

TE89 Sec. water cold coll. 3, THC 6.385 K 273.15 1273.15 +6.62 1.96 1.30 

TEOl Break flow temp., THC 4.825 K 273.15 1273.15 0.00 1.96 1.30 

TE02 BRU-A flow temp., THC 9.213 K 273.15 1273.15 0.00 1.96 1.30 

PROl Break back pressure 4.825 MPa 0.0 1.0 0.01 0.065 0.048 

PR02 Back pressure behind BRU-A 9.213 MPa 0.0 1.0 0.01 0.065 0.048 

valve 

PR21 Upper plenum pressure 3.764 MPa 0.0 16.0 0.01 0.005 0.004 

PR71 Pressuriser pressure 9.955 MPa 0.0 16.0 0.01 0.051 0.045 

PR81 SG secondary 10.010 MPa 0.0 10.0 0.01 0.032 0.028 

PR91 SIT-1 10.350 MPa 0.0 10.0 0.01 0.032 0.028 

PR92 SIT-2 10.350 MPa 0.0 10.0 0.01 0.032 0.028 

LE 11 Reactor model 0.190/8.315 kPa -60.0 100.0 79.71 0.563 0.458 

LE21 Upper plenum part 1, DP 6.750/8.315 kPa 0.0 38.0 15.21 0.134 0.109 

LE22 Upper plenum part 2, DP 4.683/6.750 kPa 0.0 10.0 20.61 0.035 0.029

CAMPNRC.DOC

17

KFKI AEKI CAMP
Table 2.3 cont. 

Identi- Location and type Elevation Unit Min. Max. C A 6 

fication (m) + + 

LE23 Upper plenum part 3, DP 3.764/4.683 kPa 0.0 16.0 8.83 0.051 0.045 

LE31 Hot leg loop seal, DP (reactor 4.802/6.225 kPa 0.0 16.0 13.96 0.051 0.045 

side) 

LE44 Cold leg part 2, DP 5.920/4.802 kPa 0.0 16.0 11.18 0.051 0.045 

LE45 SG primary, hot leg, DP 4.802/8.997 kPa 0.0 100.0 41.03 0.352 0.286 

LE46 SG primary, cold leg, DP 2.785/8.997 kPa 0.0 186.0 60.65 0.655 0.532 

LE51 Cold leg part 1, DP 2.785/5.920 kPa 0.0 38.0 31.10 0.134 0.109 

LE52 Cold leg pressure drop, reactor 3.605/4.825 kPa 0.0 25.0 12.07 0.090 0.072 

side 

LE60 Downcomer head, DP 4.505/5.355 kPa 0.0 7.50 8.29 0.016 0.013 

LE61 Downcomer, DP 0.190/4.825 kPa 0.0 60.0 45.47 0.211 0.172 

LE71 Pressuriser, DP 8.010/9.990 kPa 0.0 40.0 25.06 0.141 0.114 

LE72 Pressuriser surge line, DP 4.802/8.010 kPa 0.0 38.0 30.88 0.134 0.109 

LE81 SG secondary, DP 6.565/10.010 kPa 0.0 40.0 33.92 0.141 0.114 

LE91 SIT-i level, DP 8.13/10.35 kPa 0.0 40 21.78 0.141 0.114 

LE92 SIT-2 level, DP 8.13/10.35 kPa 0.0 40 21.78 0.141 0.114 

FL52 Core outlet, normal, venturi 5.504 kPa 0.0 60.0 0.0 0.211 0.172 

FL51 Core outlet, low flow, venturi 5.504 kPa 0.0 2.5 0.0 0.008 0.005 

FL53 Cold leg, normal, venturi 4.825 kPa 0.0 60.0 0.0 0.211 0.172 

FL54 Cold leg, low flow, venturi 4.825 kPa 0.0 2.5 0.0 0.008 0.005 

FL81 Feedwater flow, venturi 4.990 kPa 0.0 100.0 0.0 0.352 0.286 

FLO0 Break flow, venturi 4.825 MPa 0.0 1.0 0.0 0.381 0.282 

FL02 Secondary bleed flow, venturi 9.213 kPa 0.0 100.0 0.0 0.381 0.282 

MAO1 Total mass break outflow, DP - kPa 0.0 16.0 0.0 0.053 0.053 

MA02 Total mass BRU-A outflow, DP - kPa 0.0 16.0 0.0 0,053 0.045 

PW01 Electrical power - kW 0.0 1000.0 0.0 

CAMPNRC.DOC 

18

KFKI AEKI CAMIP
KFKI AEKI

Table 2.3 cont.

Identi- Location and type Elev. Unit Min. Max. C A 6 

fication (i) _+ + 

LV21 Local void in upper plenum, VP 6.225 

LV22 Local void in upper plenum VP 7.635 

LV25 Local void in upper plenum VP 4.440 

LV30 Local void in hot leg, VP 6.225 

LV32 Local void in hot leg loop seal, VP 5.400 

LV33 Local void in hot leg loop seal, VP 4.802 

LV34 Local void in hot leg loop seal, VP 4.945 

LV35 Local void in hot leg loop seal, VP 5.178 

LV41 Local void in SG hot collector, VP 5.995 

LV42 Local void in SG cold collector, VP 5.995 

LV51 Local void in cold leg, VP 3.525 

LV52 Local void in cold leg, VP 3.525 

LV71 Local void PRZ bottom, VP 7.800

Abbreviations: 

PTR = platinum resistance 

THC = thermocouple 

VP = void probe

CAMPNRC.DOC 

19

CAMP

CAMPNRC.DOC 19
KFKIAEKICAMP

Fig. 2.11 Measurement locations (1)

Fig. 2.12 Measurement locations (2)

CAMPNRC.DOC 20

KFKI AEKI CAMP

CAMPNRC.DOC 20
KFKIAEKICAMP

Fig. 2.13 Measurement locations (3)

3. TEST DEFINITION AND OBJECTIVES 

The CAMP-CLB test primarily addresses the question whether the secondary bleed is effective to 

recover the core without the availability of the HPI systems if the break is too small to 

depressurise primary system below secondary pressure. 

The specific features of the experiment are as follows: 

"* The test begins from a steady-state condition with nominal parameters. 

"* The break location is in the cold leg (at downcomer head), with a size of 2%. In the PMK-2 

the nozzle diameter is 1.3 mm. 

"* 2 HAs are available in the test modelled by one safety injection tank (SIT) injecting to the 

downcomer, the water temperature is 293 K. 

"* No HPIS applied to the test. 

"* Scram is initiated low primary pressure of 11.3 MPa (the decay heat is stabilised at 32.5 kW). 

"* Secondary side is isolated 10 s after scram. 

"* The pump coast-down begins by high containment pressure signal - 0.11 MPa - supposed at 

t=80 s. 

"* The secondary bleed is modelled by the BRU-A valve (PV23). In the PMK-2 the nozzle 

diameter is 4.0 mm. 

"* No secondary feed is modelled. 

The main objective of the test is to study the following phenomena: 

"• effect of hot leg loop seal behaviour on primary flow, steam generator heat transfer, 

hydroaccumulator injection 

"* substantial core heat-up due to loop seal effects

KFKI AEKI CAMP

CAMPNRC.DOC 21
* effectiveness of secondary side bleed to recover the core and reinitiate hydroaccumulator 

injection. 

4. TEST DESCRIPTION 

The CAMP-CLB experiment - as specified in Section 3 - is presented in detail below [11]. 

4.1 Initial conditions 

The initial steady state conditions of the test are summarised in Table 4.1 (for last column see 

Section 6). The parameters are nearly the same as the nominal operating parameters of the plant 

considering the scaling ratio. 

Table 4.1 

Unit Nominal Test Calculation 

Primary pressure MPa 12.3 12.28 12.325 

Core inlet temperature K 541 539.6 538.17 

Primary loop flow rate kg/s 4.5 4.4 4.4 

Core power kW 664 663 661.1 

Pressuriser level m 9 8.868 8.865 

Hydroaccumulator level m 9.65 9.663 9.665 

Hydroaccumulator pressure MPa 5.9 6 6 

Secondary pressure MPa 4.6 4.5 4.49 

Secondary flow rate kg/s 0.36 0.47 0.55 

Feedwater temperature kg/s 496 471.2 471.2 

Steam generator level m 8.4 8.43 8.159 

4.2 Boundary conditions 

The boundary conditions are listed in Table 4.2. 

Table 4.2 

Unit Nominal Test Calculation 

Break opening at s 0 0 0 

Scram by low primary pressure MPa 11.3 11.18 11.15 

Secondary side isolated (scram +) s 10 9 10 

Pump coast-down initiated at s 80 80 80 

Duration of pump coast-down s 148 138 150 

SIT injection starts MPa 5.9 6 6 

Steam dump opens MPa 5.3 5.35 5.35 

Steam dump closes MPa 4.9 4.915 4.92 

Secondary bleed initiated Tclad K 730 731 1505. s* 

SIT empty m 8.25 8.27 8.27 

Test terminated s 3600 3596 3600

*synchronised boundary condition

CAMPNRC.DOC 22

1 A "A4'D

CAMPNRC.DOC 22

KFKI AEKI
KFKIAEKICAMP

4.3 Sequence of major events 

The measured sequence of major events of the test are presented in Table 4.3.

Table 4.3

Test

Break opening 

Scram generated 

Secondary side isolated 

Pressuriser emptied 

Pump coast-down initiated 

SIT injection starts 

End of pump coast-down 

Vessel level at hot leg elevation 

Hot leg loop seal clearing 

Steam dump first opens 

Steam dump first closes 

Steam dump opens again 

Steam dump closes 

Rod temperatures begin to rise 

Cold leg loop seal opening 

First peak rod temperature

0. S 

28. s 

37. s 

43.s 

80. s 

159. s 

218. s 

240. s 

352. s 

469. s 

504. s 

897. s 

946. s 

1115.s 

1150.s 

1179.s 

711. K 

1260. s 

712. K 

1410. s 

1504. s 

1514. s 

742. K 

2548. s 

3596. s

"* Second peak rod temperature 

"* Temperatures escalate again 

"* Secondary bleed initiated 

"* Maximum rod temperature

SIT empty 

Test terminated

Calculation 

0. S 

21. s 

32. s 

34. s 

80. s 

118.s 

230. s 

216. s 

344. s 

495. s 

515. s 

847./1226. s 

887./1264. s 

1036. s 

1038. s 

1046. s 

596. K 

1460. s 

1505. s 

1526. s 

726. K 

2481. s 

3600. s

4.4 Results of the test 

The time history of the measured parameters characterising the transient process and the 

phenomena under consideration are plotted on Figs. 4.1 - 4.30 (on the figures TS01 and TS02 are 

the saturation temperatures derived from the primary and secondary pressures). The first 20 

minutes are presented in zoomed graphs: Figs. 4.1z - 4.30z. Results of local void probe 

measurements in comparison to the measured levels are shown in Figs. 4.31 to 4.37. (The 

position of 50 % void corresponds to the elevation of the probe). The figures are shown in 

Appendix 1. 

4.5 Reproducibility of the test 

In general an experiment must be repeated several times to get the expected transient and 

accurate database for code validation. This offers the opportunity to answer the question to what 

extent a test at the PMK-2 facility is reproducible. Since in the case of the CAMP-CLB test only

0 

S

KFKI AEKI CAMP

CAMPNRC.DOC 23
KFKI AEKI CAMP 

the third experiment (marked with exp.2) was declared as a successful one (and described in this 

paper) it is worth presenting some comparison plots with the results of the second one (exp.1) 

which had been rejected because of failure of recording the void probe data. 

The main deviations in initial conditions were: exp. 1 exp.2 

primary pressure 12.50 MPa 12.28 MPa, 

secondary pressure 4.44 MPa 4.50 MPa, 

core inlet temperature 538.6 K 539.6 K. 

As a consequence of this differences the scram was in exp. 1 at 50 s against 28 s. Nevertheless the 

main characteristics of the two tests are very similar - because of the close initial state of the 

facility and the same boundary conditions - as shown in Appendix 1 by Figs. 4.38 - 4.40. The 

main parameter of exp. 1, the peak cladding temperature is 697 K at 1509 s against 742 K at 1514 

s for the exp.2. 

5. EVALUATION OF TEST RESULTS 

The transient is initiated by opening the break. The system pressures in Fig. 4.1z show a 

characteristics typical to that of small break LOCA accidents: in early phase of the transient the 

primary pressure and pressuriser level decreases rapidly. The primary pressure (PR21) begins to 

stagnate as soon as upper head and SG hot collector reach saturation (Fig. 4.14z - TE24) and start 

voiding. 

Scram is generated by low primary pressure of 11.18 MPa and from 28 s the core power reduces 

to decay heat level (see Fig. 4.30z). The pressuriser level decreases from its initial value (Fig. 

4.7z - LE7 1), after the scram this becomes more rapid and the PRZ is empty at 41 s. 

After secondary side isolation (scram + 9 s) the secondary pressure (PR81) quickly increases 

(Fig. 4. 1 z), but up to 469 s does not reach the steam dump set-point due the decrease of hot leg 

temperatures (Fig. 4.14z - TE22 and Fig. 4.15z - TE41). 

MCP coast down begins at 80, at the end of pump run out natural circulation is established as can 

be seen in Fig. 4.24z. After 850 s there is no natural circulation, below 0.2 kg/s value of flow rate 

the curve of narrow range measurement (FL54) is valid. 

Two HAs (modelled by one vessel) are available and the injection is actuated at a primary 

pressure of 6.0 MPa at the transient time of 159 s, but injection is immediately stopped by the 

increasing primary pressure (Fig. 4.2z - PR91 and Fig. 4.8 - LE91). The pressure and level 

increase are not limited because the check valve of the SIT is not modelled in PMK-2. 

At 88 s the vessel level starts to decrease (Fig. 4.3z - LEl and Fig. 4.4z - LE21) and at 240 s 

drops to the hot leg elevation and begins to stagnate. The hot leg loop seal clearing process is 

started at about 280 s (Fig. 4.5z - LE31 and Fig. 33). As a consequence, primary pressure 

increases and vessel level is depressed again, while loop flow rate (Fig. 4.24z) is decreasing. 

At 352 s the hot leg loop seal (HLLS) starts to vent steam, as evidenced by the decreasing SG hot 

collector level (Fig. 4.5z - LE45) and void measurement (Fig. 34). This involves: 

CAMPNRC.DOC 24
"* recovering loop flow rate (Fig. 4.24z); 

"* enhanced SG heat transfer (see secondary pressure increase in Fig. 4.1 z); 

"* decreasing primary and increasing secondary pressures leading to steam dump opening at 469 

s, closing at 504 s (Fig. 4.28z); 

"* recovery of the vessel level (Fig. 4.3z); 

"* renewed SIT injection (Fig. 4.8z); 

"• the SG side of the cold leg loop seal (CLLS) starts to empty (Fig. 4.6z - LE46). 

However, due to the fact that the break cannot remove the energy produced by the core, the 

primary pressure stabilises and SIT injection stops at about 600 s. This leads to further decrease 

of the primary mass inventory: 

"* vessel and SG collector levels are decreasing (Figs. 4.3z and 4.5z); 

"* loop flow decreases (Fig. 4.24z) 

"* heat transfer to secondary side deteriorates, secondary pressure increases only slowly. 

At 897 s the steam dump opens again (Fig. 4.28z), resulting in temporarily improved primary to 

secondary heat transfer, increased loop flow and vessel level (Fig. 4.3z). However, stagnation 

conditions soon prevail, the SG side of the CLLS continues to empty (Fig. 4.6z - LE46) and 

opens at 1150 s. 

When the core collapsed level drops to about 3 m fuel rod imitator temperatures begin to rise 

(1115 s) not only at core outlet (Fig. 4.12z), but at an elevation 0.45 m below as well (Fig. 

4.11z). The first peak is limited to 711 K at 1179 s (Fig. 4.13z) due to partial opening of the 

CLLS: steam vented via the CLLS to the break results in core level recovery (Fig. 4.3z) and 

partial rewetting of heater rods (Fig. 4.1 lz). 

Oscillatory behaviour can be observed for about 200 s in loop flow (Fig. 4.24 - FL54), cold leg 

(Fig. 4.36 - LE52) and vessel levels (Fig. 4.3) that limits the second maximum of heater rod 

temperatures (712 K at 1260 s). Finally, as loop parameters tend to stabilise and mass inventory 

further decreases, core temperatures again escalate from 1410 s (Figs. 4.12z and 4.13z). 

At a heater rod temperature of 730 K secondary bleed is started (Fig. 4.28). Condensation on the 

SG primary side quickly reduces primary pressure (Fig. 4.1), enhances loop flow temporarily 

(Fig. 4.24 - FL54) and allows core level to recover: as a consequence, heater rods are rewetted 

after a maximum temperature of 742 K at 1514 s (Fig. 4.13z - TEl9). SIT injection is activated, 

leading to increasing vessel inventory. 

As a consequence of the secondary bleed without feed the level in SG is decreasing (Fig. 4.9) and 

some of the temperature sensors (thermocouples) in the SG secondary side show superheated 

steam after 2000 s, as can be seen in Fig. 4.20 (TE80, TE82), Fig. 4.21 (TE83, TE85) and Fig. 

4.22 (TE86). 

At 2548 s the SIT runs empty (injection is stopped by level criterion, see Fig. 4.8) that again 

leads to decreasing mass inventory. Repeated core temperature increase after some 2000 s later 

should be limited by the low pressure injection. The set-point of low pressure ECCS was not 

reached during the one hour of the transient.

KFKI AEKI CAMP

CAMPNRC.DOC 25
6. POST TEST ANALYSIS 

6.1 Modelling aspects of RELAP5 analyses 

The RELAP5/MOD3 code was the tool for most of the pre-test and post-test analyses of PMK-2 

tests with good experiences. The short summary of the RELAP5 input model and nodalisation is 

given below. 

A general RELAP5 model for the PMK-2 facility has been developed and validated already for 

the analyses of different IAEA Standard Problem Tests [4] and in the different EU-PHARE 

projects (pre- and post-test calculations) [9]. RELAP5 model has been continuously upgraded 

during the last decade on the basis of experiences of different PMK tests and taking into 

consideration requirements of the new RELAP5 versions. The standard PMK-2 nodalisation is 

given in Fig. 6. The nodalisation scheme consists of 119 volumes including 14 time dependent 

volumes, 128 junctions including 5 time dependent junctions and 92 heat structures with 395 

mesh points. Some details are given in Table 6.1. 

As the main character of the input model the core is represented by nine control volumes in one 

channel, seven from them covering the active lengths of the heated core. The steam generator 

heat transfer tube bundle is simulated by three horizontal channels, with three control volumes in 

each, while in the secondary side there are three vertical channels. 

Table 6.1 

PMK-2 nodalisation 

GROUPS OF COMPONENTS COMPONENT NUMBER 

NUMBERS OF NODES 

Hot leg 100-112 7 

Primary side of steam generator 120-156 19 

Cold leg from steam generator collector to pump 160-164 3 

simulator bypass 

Pump simulator bypass valves MV11, MV12, PV11 190-192 

Pump simulator bypass tubes 166-176 6 

Cold leg from pump simulator tubes to downcomer 178-186 5 

Reactor vessel 200-250 26 

LPIS system 620-623 2 

HPIS system 624-625 1 

Accumulators SIT-1 and SIT-2 660-682 4 

Pressuriser, surge line, spray line, safety valve 400-450 14 

Break simulator 618-619 1 

Feedwater simulation 580-592 4 

Secondary side of steam generator 500-560 15 

Safety, relief and steam dump valves 598-628 4

CAMPNRCDOC 

26

KFKI AEKI CAMP

CAMPNRC.DOC 26
KFKIAEKICAMP

Fig. 6 

PMK-2 nodalisation scheme for RELAP5/mod3.2 

6.2 Initial and boundary conditions 

The nominal and the measured initial conditions together with the data from the post test 

calculation (after 100 s steady-state run) are presented in Table 4.1. The scenario of the actions 

representing the boundary conditions are shown in Table 4.2 (Tables are in Section 4). 

6.3 Run parameters and critical flow options 

In the post-test calculation a time step limit of 0.01 s was chosen. For the heat losses from 

primary to the environment 4 W/m2K, from SG 8 W/m2K as heat transfer coefficients were used. 

At the break and the steam dump valve the Henry-Fauske critical flow model was applied, the

KFKI AEKI CAMP

CAMPNRC.DOC 27
discharge coefficient was set to 0.85, while the thermal nonequilibrium constant to 0. 14. 

The post-test was calculated using the developmental code version RELAP5/mod3.2.2Gamma 

[8] on a PC Pentium 1I 350 computer under Windows-NT with performances: CPU 

time/transient time = 18 887s/3700s = 5, advancements = 548185 and emass/system mass = 0.045 

kg/1002.7 kg. 

6.4 Sequence of major events 

The results of the post-test calculation in term of the sequence of major events are presented in 

Table 4.3. The time history of the characteristic parameters are displayed on comparison figures 

in Appendix 2 by Figs. 6.1 - 6.20. 

Although the agreement between the measured and calculated curves is fairly good some remarks 

must be added to the figures: 

"* Figs. 6.2 and 6.9: the steam dump valve opens three times in the calculation instead of two as 

in the test (in the calculation the pressure controlled operation of the BRU-A and the operator 

initiated bleed are modelled by two valves: 600 and 602 - see Fig. 6). 

"* Figs. 6.3, 6.4 and 6.9: the critical flows seem to be low, but higher discharge coefficient leads 

to loss of the core heat-up (see Chapter 7); 

"• Figs. 6.7 and 6.8: the pressure and level increase in the calculation is limited because the 

check valve in RELAP accumulator model is included; 

"* Figs. 6.11, 6.13 and 6.14: the hot leg loop seal behaviour is good (compare LEll and RV 

calculated levels on Fig. 6.11), but there is no stagnation after HILLS clearing, so the cold leg loop seal opens earlier by about 120 s, an oscillation appears after this as it was in the test 

because of incomplete loop seal clearing; 

"* Fig. 6.11: the minimum collapsed level in RV is predicted deeper than the measured level by 

about 0.5 m 

"* Figs 6.15 and 6.16: the effect of SIT injection on the cold part temperatures is higher in the 

test, after the termination of the injection (2500 s) the decrease of TE63 continues 

unexplainable; 

"• Fig. 6.20: the first core heat-up in the calculation is very short because total rewetting occurs 

before oscillatory behaviour can be observed. 

7. SENSITIVITY CALCULATIONS 

During the post-test analysis it was found, that the core heat-up is very sensitive to small changes in some parameters leading to suppression of the temperature excursions. Two types of 

sensitivity study were performed to see the effect of two input parameters: the requested (maximum) time step and the heat loss (i.e. heat transfer coefficient to the environment) of the 

steam generator. 

7.1 Study on the Maximum Time Step 

In first series four calculations were made with time step limitations as follows:

KFKI AEKI f'AMP

CAMPNRC.DOC 28
dt = 0.1 s, 0.05 s, 0.01s and 0.001s. 

The results are presented by curves of some sensitive output parameters: the timing of steam 

dump valve operation and the heater rod temperature escalation as well as by secondary pressure 

and reactor vessel level (Figs. 7.1 - 7.4). In Figs. 7.1 and 7.2 can be seen that with dt = 0.001 and 

0.01 s in time period of 400 - 800 s the first BRU-A opening and the secondary pressure is very 

close to the measured one, but later, at 1200 s a third actuation occurs due to the quicker pressure 

increase. Using higher time step limit the first opening shifted near to 700 s and the third action 

is disappeared. The rod temperature peak at 1500 s is the highest with dt = 0.05 s and lowest with 

0.001 s time step. Finally the first small temperature increase disappears totally with dt = 0.1 s 

time step. 

To investigate the changes between dt = 0.05 and 0.01 s new runs with requested time step = 

0.02 and 0.025 s were performed. In both cases the results are very close together but 

unexpected: Figs. 7.5 - 7.7 present surprising changes in timing of valve operations (those aren't 

between dt = 0.05 and 0.01 s but between 0.1 and 0.05 s), in RV collapsed level (it increases at 

1085 s above 3.0 m and sharply oscillates between 1100 and 1500 s of transient time), finally in 

rod temperature (its increase disappeared totally as a consequence of oscillation). 

7.2 Study on the SG Heat Losses 

The heat transfer coefficient to the environment at SG was varied between 6 and 15 W/m2K. The 

results are shown in Figs. 7.8 - 7.14. As shown in Figs. 7.8 - 7.9 if the value is 12 or greater the 

BRU-A valve opens only two times. There is no effect on the SG cold collector level history 

(Fig. 7.9), still at the other side of the CLLS (Fig. 7.11), as well as at the RV level (Fig. 7.12) the 

oscillation like in Fig. 7.6 turns up. Simultaneously the temperature excursion disappears (Fig. 

7.14). 

7.3 Study on discharge coefficient 

The discharge coefficient of HF critical flow model was varied between 1.0 and 0.85. The results 

for values of 0.85 (the presented calculation) and 0.90 are shown in Figs. 7.15 - 7.22. (Using 

discharge coefficients of 0.95 and 1.0 resulted in the same behaviour as for 0.90). The history of 

displayed parameters shows similar changes - a strong oscillation (see Figs. 7.18 and 7.20) and the 

absence of the temperature excursion (see Fig. 7.22) - as in the cases of time step and heat loss 

variations. 

The "bifurcation type" behaviour encountered in parametric studies could be the result of the 

code calculating by different constitutional models depending on the maximum time step or 

secondary heat losses. Because there is no explanation of the strong oscillation during the partial 

clearing of the cold leg loop seal till now this was reported as a new RELAP5 User Problem.

CAMPNRC.DOC 

29

KFKI AEKI CAMP

CAMPNRC.DOC 29
8. CONCLUSIONS 

The 2 % SBLOCA test was performed according to the test definition. The test results show a 

number of important phenomena: 

"* effect of hot leg loop seal behaviour on primary flow, steam generator heat transfer, 

hydroaccumulator injection 

"* inefficiency of hydroaccumulators on the downcomer side if the break is too small to 

depressurise below secondary pressure 

"* substantial core heat-up due to loop seal effects 

"* effectiveness of secondary bleed to recover the core and reinitiate hydroaccumulator 

injection. 

The test may be quite demanding for code validation in the following aspects: 

"* partial clearing of the loop seals 

"* vapour condensation in the horizontal, parallel tubes of the SG 

"* effect of condensation in the SG on primary mass inventory distribution (i.e. vessel and loop 

levels) 

"* prediction of the oscillatory behaviour during partial clearing of the CLLS, including repeated 

core heat-up. 

Results of post-test analysis with RELAP5/mod3.2.2Gamma show quite good agreement 

regarding the main system parameters and partly the important phenomena as presented in the 

previous chapters. 

The "bifurcation type" behaviour encountered in parametric studies could be the result of the 

code calculating by different constitutional models depending on the maximum time step or 

secondary heat losses. This behaviour needs further investigation. It was discussed with the code 

developers and it was taken as a new RELAP5 User Problem.

CAMPNRC.DOC 

30

KFKI AEKI /•AN/IP

CAMPNRC.DOC 30
KFKIAEKICAMP

9. REFERENCES 

[1] K. Liesch, M. R6ocreux: Report on verification matrix for thermohydraulic system codes 

applied for WWER analysis. Garching/Cadarache, July 1995. 

[2] I. T6th, Gy. Itzs6l, L. Szabados: Task3 - Extension of the validation matrix, Proposals for 

PMK-2 tests. KFKI Atomic Energy Research Institute. Budapest, May 1998. PHARE 

SRR3/95 Project report TIERSDI/4NT/2462/3, rev. 1. 

[3] L. Szabados et al: PMK-2 HANDBOOK, Technical Specification of the Hungarian 

Integral Test Facility for VVER-440/213 Safety Analysis. KFKI Atomic Energy Research 

Institute. Budapest, 1996. TIERSDL/4NT/2459/41. 

[4] IAEA-TECDOC-425 (1987) Vienna, IAEA-TECDOC-477 (1988) Vienna, IAEA

TECDOC-586 (1991) Vienna, IAEA-TECDOC-848 (1995) Vienna. 

[5] tzsdl, Gy. et al.: Simulation of a Small Cold-Leg-Break Experiment at the PMK-2 Test 

Facility using the RELAP5 and ATHLET Codes, Nuclear Technology, 1997, Vol. 118, 

pp. 162-174. 

[6] tzs61, Gy., Szabados, L.: Safety Related Thermohydraulic Experiments for VVER 

Reactor Systems. ICONE-6. San Diego, California, USA, May 10-14, 1998. ICONE

6354. Proc. on CD. 

[7] L. Szabados et al.: Experimental Data Report for 0.5% Cold Leg Break Overfed by HPIS. 

The CLB-PH Experiment. PH SRR3/95 Project report, PH SRR3/R05, Atomic Energy 

Research Institute, Budapest, July 1999. 

[8] RELAP5/MOD3 Code manual. (RELAP5/MOD3.2.2Gamma) Volumes I to VI. The 

Thermal Hydraulics Group, SCIENTECH, Inc., Formally NUREG/CR-5535, June 1999. 

[9] L. Perneczky et al.: RELAP5/MOD3.2.2 Pre-Test Analysis for Test 3. 7.4% Cold Leg 

Break Without HPIS and With Secondary and Primary Bleed. PH SRR3/95 Meeting, 

Budapest, September 30 - October 1, 1999. 

[10] L. Perneczky and I. T6th: Pre-test Calculations of PMK-2 Tests Using 

RELAP5/MOD3.2.2Beta, Fall 1998 CAMP Meeting, Bethesda, October 21-23, 1998. 

[11] I. T6th et al.: Test Results of the PMK 2% SBLOCA Experiment, Spring 2000 CAMP 

Meeting, Terrasini, April 17-19, 2000.

CAMPNRC.DOC 

31

31

KFKI AEKI CAMP

CAMPNRC.DOC
KFKI~~ MEICA'P

APPENDIX 1

CAMPNRC.DOC 

32

KFKI AEKI CAMP

CAMPNRC.DOC 32
KFKIAEKICAMP

PMK-2 CAMP EXPERIMENT 

Fig. 4.1 Primary (UP) and Secondary Pressures 

Pressure (MPa) 

pr21 

12 pr8l 

10 

8 

6 

4 

2 

0 500 1000 1500 2000 2500 3000 3500 

Time (s) 

PMK-2 CAMP EXPERIMENT 

Fig. 4.1z Primary (UP) and Secondary Pressures 

Pressure (MPa) 

13 . . . . . . .. .. . . . . 

pr21 12 pr8l 

10 

9 

8 

7 

6 . 

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

4. " * 8 I i* . . * , . I , , , , i * , 

0 200 400 600 800 1000 1200

Time (s)

CAMPNRC.DOC 33

KFKI AEKI CAMP

CAMPNRC.DOC 33
KFKI AEKIC AMlP

PMK-2 CAMP EXPERIMENT

Fig. 4.2 Pressurizer and Hydroaccumulator Pressures

Pressure (MPa) 

14 ....

500 1000 1500 2000 2500 3000 

Time (s)

PMK-2 CAMP EXPERIMENT

Fig. 4.2z Pressurizer and Hydroaccumulator Pressures

Pressure (MPa) 

13 c--

200 400 600 800 1000 

Time (s)

CAMPNRC.DOC 34

12 

10 

8 

6 

4 

2 

0

0 3500

12 

11 

10 

9 

8 

7 

6 

5

0 1200

KFKI AEKI C A ]•bAP

CAMPNRC.DOC 34
KFKIAEKICAMP

PMK-2 CAMP EXPERIMENT 

Fig. 4.3 Collapsed level in the Vessel 

Level (m) 

lell 

8 

7 

6 

5 

4 

3 

21 

0 500 1000 1500 2000 2500 3000 3500 

Time (s) 

PMK-2 CAMP EXPERIMENT 

Fig. 4.3z Collapsed level in the Vessel 

Level (m) 9I 

lell 

8 

7 

6 

5 

4 

3 

2 

0 200 400 600 800 1000 1200

Time (s)

CAMPNRC.DOC 

35

KFKI AEKI CAMP

CAMPNRC.DOC 35
FKI~9 (A4PAEK 

PMK-2 CAMP EXPERIMENT

Fig. 4.4 Levels in the Vessel

Level (in) 8.5 

7.5.

I -I , 

le21 

le22 

le23-------

-

S ~ 1~***~ ~ "'~------ o

II I . . I -

500 1000 1500 2000 2500 

Time (s)

3000 3500

PMK-2 CAMP EXPERIMENT 

Fig. 4.4z Levels in the Vessel

200 400 600 800 1000 

Time (s)

CAMPNRC.DOC 

36

6.5 

6 

5.5 

5 

4.5 

4 

3.5 I I I I I i I

0

Level (in) 

8.5 

8 

7.5 

7 

6.5 

6 

5.5 

5 

4.5 

4 

3.5

0 1200

I . lI lI -l lTl-r I.I. l-vl- I.I. . . ..

S. . . , I . . . . . . . . . I I

('• A N/[P

7

I . . . I . . . I

- - - - -

. . I

CAMPNRC.DOC 36

KFKI AEKI
KFKI AEKI CAMP

PMK-2 CAMP EXPERIMENT

Fig. 4.5 Hot Leg Loop Seal Level

500 1000 1500 2000 2500 3000 

Time (s)

PMK-2 CAMP EXPERIMENT

Fig. 4.5z Hot Leg Loop Seal Level

200 400 600 800 1000

Time (s)

CAMPNRC.DOC 

37

Level (m) 

8.5 E--

8 

7.5 

7 

6.5 

6 

5.5 

5 

4.5

0 3500

Level (m) 

8.5 F=

8 

7.5 

7 

6.5 

6 

5.5 

5 

4.5

0 1200

KFKI AEKI CAMP

CAMPNRC.DOC 37
KFKI EKI UAMP

PMK-2 CAMP EXPERIMENT 

Fig. 4.6 Cold Leg Loop Seal Levels

Leve 1 (m)

9 

8 

7 

6 

5 

4 

3 

2

1000 1500 2000 

Time (s)

2500 3000

PMK-2 CAMP EXPERIMENT 

Fig. 4.6z Cold Leg Loop Seal Levels

Level (m) 

9 [r,

200 400 600 800 1000 

Time (s)

CAMPNRC.DOC 

38

500

' H I ' IT J H I * S * I I, I j I ' I V I . ' 'I ' ' 

le46 

ele51 

_e52------

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

-

a . . . . I I

0 3500

8 

7

5 

4 

3

0 1200

KFKI AEKI V• A• V A•

, I ,,I,,,,I I . . .

CAMPNRC.DOC 38
KFKI~ AEK CAP

PMK-2 CAMP EXPERIMENT

Fig. 4.7 Pressurizer and Surge Line Level

Level (m) 

9 ,'

-I 

-I 

-I . :I 

-II

le71 

le72

A

f i 

ItI I 

Is'i III 

I Ii 

I I, 

I ' I 

.1... I I.

500 1000 1500 2000 2500 3000 3500

Time (s)

PMK-2 CAMP EXPERIMENT 

Fig. 4.7z Pressurizer and Surge Line Level

Level (m) 9 , 

8.5 -

r . . . . * S 5 5 * 

le71 

le72

:1 

- I - I 

- I - I 

I 

Ia<T'.

0

/ 

V 

/ 

/ 

Ih'

d 

I I 

I 

1 

/ 

I 

I

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

/I' 

'I 

I__/

/5F 

*/ 

/ 

/ 

I 

/ 

I 

/ 

/ 

I 

I 

/

I - . . . S - - - - I - -

200 400 600 

Time (s)

800 1000

CAMPNRC.DOC 

39

8.5 

8 

7.5 

7 

6.5 

6 

5.5 

5

0

8 

7.5 

7 

6.5 

6 

5.5 

5

1200

I

S. . . . i I N If . .A . . . . .I ... a ,III| I I I, lI

KFKI AEKI •AN/IP

" " " . . . I . . . I I I

| I 

| 

I

11

I

I
KFKI~~ UEIAP

PMK-2 CAMP EXPERIMENT 

Fig. 4.8 Hydroaccumulator Level 

Level (m) 10 .. . . . . 

le9 1 9.8 

9.6 

9.4 

9.2 

9 

8.8 

8.6 _ 

8.4 

8.2 . . 

0 500 1000 1500 2000 2500 3000 3500 

Time (s) 

PMK-2 CAMP EXPERIMENT 

Fig. 4.8z Hydroaccumulator Level 

Level (m) 

9.85 

le91 

9.8 

9.75 

9.7 

9.65 

9.6 

9.55 

9.5 

0 200 400 600 800 1000 1200 

Time (s) 

CAMPNRC.DOC

KFKI AEKI CAMP

14U
KFKIAEKICAMP

PMK-2 CAMP EXPERIMENT 

Fig. 4.9 SG Secondary Level

Level (m) 

8.6 r0 500 1000 1500 2000 2500 3000 3500

PMK-2

Time (s) 

CAMP EXPERIMENT

Fig. 4.9z SG Secondary Level

Level (m) 

8.47 

8.46 

8.45 

8.44 

8.43 

8.42 

8.41 

8.4 

8.39 

8.38 

8.37 -

0 200 400 600 800 1000

CAMPNRC.DOC 41

8.4 

8.2 

8 

7.8 

7.6 

7.4

Time (s)

1200

KFKI AEKI CAMP
KFKI EKIC AMP

PMK-2 CAMP EXPERIMENT 

Fig. 4.10 Heater Rod Temperatures 

Temperature (K) 

590 .... . .. .g, . 

580 tel0

tel l 570 tet2 

560 

550 

540 

530 

520 

510 

500 

490 

480 . . . . 

0 500 1000 1500 2000 2500 3000 3500 

Time (s) 

PMK-2 CAMP EXPERIMENT 

Fig. 4. 1Oz Heater Rod Temperatures 

Temperature (K) 

585 .. . . , 

580 tel0 

"tel 1 575 tel2 

570 

565 

560 

555 , 550 ,.... .. / • • 

545 •/\ . .. . . . . . . 

540 

535 

530 ., . ., . . . . , I . 0 200 400 600 800 1000 1200 

Time (s)

CAMPNRC.DOC 42

KFKI AEKI i•A •VrP
KFKIAEKICAMP

PMK-2 CAMP EXPERIMENT

Fig. 4.11 Heater Rod Temperatures

Temperature (K) 

640 r-.-.-

0 500 1000 1500 2000 2500 

Time (s)

3000 3500

PMK-2 CAMP EXPERIMENT

Fig. 4.1 lz Heater Rod Temperatures

Temperature (K)

0 200 400 600 

Time (s)

800 1000

CAMPNRC.DOC 

43

620 

600 

580 

560 

540 

520 

500 

480

uvi tel3 

620 S~~tel4-.-

610 

600 

590 

580 

570 

560 

550 

540

1200

KFKI AEKI CAMP

CAMPNRC.DOC 43
KFKI AEKI C A Au P

PMK-2 CAMP EXPERIMENT

Fig. 4.12 Heater Rod Top Temperatures

Temperature (K) 

750 ....

500 1000 1500 2000 2500 3000 

Time (s)

PMK-2

3500

CAMP EXPERIMENT

Fig. 4.12z Heater Rod Top Temperatures

Temperature (K) 750r1100 1200 1300 1400 1500 1600 

Time (s)

CAMPNRC.DOC 44

700 

650 

600 

550 

500 

450

0

700 

650 

600 

550 

500

1000 1700

KFKI AEKI FAM/D
KFKIAEKICAMP

PMK-2 CAMP EXPERIMENT 

Fig. 4.13 Heater Rod Top Temperatures

Temperature (K) 

750 r---.--

0 500 1000 1500 2000 2500 3000 

Time (s)

PMK-2

3500

CAMP EXPERIMENT

Fig. 4.13z Heater Rod Top Temperatures

Temperature (K) 

750 r-'----

700 

650 

600 

550 

500

1000 1100 1200 1300 1400 1500 1600 

Time (s)

1700

CAMPNRC.DOC 

45

700 

650 

600 

550 

500 

450

KFKI AEKI CAMP

CAMPNRC.DOC 45
INX xr zj. CAMP 

PMK-2 CAMP EXPERIMENT 

Fig. 4.14 Vessel Temperatures 

Temperature (K) 

600 . . . ... I. .. I .. 

te22 

580 te24 

tesI 

560 

540 

520 

500 -- -- =--. 

480 

460 r 

0 500 1000 1500 2000 2500 3000 3500 

Time (s) 

PMK-2 CAMP EXPERIMENT 

Fig. 4.14z Vessel Temperatures 

Temperature (K) 

600 

te22 

590 , te24 

tes 1-----

580 ', 

570 

560 

550 "•. 

540 

5 3 0 . . . . ' ' ' ' ' , t . . 

0 200 400 600 800 1000 1200 

Time (s) 

CAMPNRC.DOC , 40

T."li•l.rt ,t, 17t.-"t
KFKI AEKI CAMP

PMK-2 CAMP EXPERIMENT

Fig. 4.15 SG Inlet and Outlet Temperatures

Temperature (K) 

AKOn

500

te4l 

te42 

tesl------

tes2 ........... 

I. 

1000

PMK-2

1500 2000 2500 

Time (s) 

CAMP EXPERIMENT

3000

Fig. 4.15z SG Inlet and Outlet Temperatures

Temperature (K) 

600 ....

0 200 400 600 800 1000 1200

Time (s)

CAMPNRC.DOC 47

'kt iLk/ 

580 

560 

540 

520 

500 

480 

460

0 3500

590 

580 

570 

560 

550 

540 

530

KFKI AEKI CAMP
PMK-2 CAMP EXPERIMENT 

Fig. 4.16 Cold Leg Temperatures

Temperature (K) 

600 ... 

580 

560 ', ----. 

540 

520 

500 

480 

460 

440 

420 

400 

380 

0 500 1000 1500 2000 2500 3000 

Time (s)

PMK-2

Temper 

600 

580 

560 

540 

520 

500 

480

CAMP EXPERIMENT

Fig. 4.16z Cold Leg Temperatures 

ature (K) 

te63 

te6l 

tesI-------

-------

I .I 

II 

\ ,- , 

p I , * I , . I , * , p I i , 

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

0 200 400

CAMPNRC.DOC

600 

Time (s)

800 1000 1200

48

KFKI AEKI

C A A,D -tk1VJ.1i

3500

A' A "Ar'
KFKIAEKICAMP

Temper 

600 

580 

560 

540 

520 

500 

480

4oU (

PMK-2 CAMP EXPERIMENT 

Fig. 4.17 Upper Plenum and Downcomer Wall Temperatures

ature (K) 

4

I . . . I , I.

te23 

te62 A7

tesl-----

,--------------------------------------------------

) 500 1000 1500 2000 2500 3000 3500 

Time (s)

PMK-2 CAMP EXPERIMENT 

Fig. 4.17z Upper Plenum and Downcomer Wall Temperatures 

Temperature (K) 

600 .... te23 

590 te62 ---

tes1 

580 

570 

560 

550 "-- - - - - -

540 . "- --------....... 

530.. . . . . . 

520 . . . . . . . . ' . . . . , . .

0 200 400 600 

Time (s)

800 1000 1200

CAMPNRC.DOC 49

KFKI AEKI CAMP

v I I
KFKIAEKICAMP

PMK-2 CAMP EXPERIMENT

Fig. 4.18 SG Hot Collector Temperatures

Temperature (K) FAnn . I...

580 

560 

540 

520 

500 

480 

460

1000

'''I',,, I.

_~~~ . . . . . I . , .. I . . . . . , . , ' - •• , . . te43 

te45 

te471------

tes 1 -..........

I . . . . I . . I ! I I I

0 500 1500 2000 2500 3000 3500

Time (s)

PMK-2 CAMP EXPERIMENT 

Fig. 4.18z SG Hot Collector Temperatures

Temperature (K) 

600 .r. .

200 400 600

Time (s)

CAMPNRC.DOC

50

590 

580 

570 

560 

550 

540 

530

te43 

te45 

te47 

tes I ---- -

-t e......... .

- . I I I -r I ý-•'--, I , ,_, - lI I ,ll .

0 800 1000 1200

I I. . . . i I I I i i

KFKI AEKI CAMP

.'L I* 

vvv IIIIIIIIIm
KFKIAEKICAMP

PMK-2 CAMP EXPERIMENT

Fig. 4.19 SG Cold Collector Temperatures

Temperature (K) Ann I] ...

500 1000 1500 2000 2500 3000 3500

Time (s)

PMK-2 CAMP EXPERIMENT

Fig. 4.19z SG Cold Collector Temperatures

Temperature (K) 

Ann . I

200 400 600 

Time (s)

800 1000 1200

CAMPNRC.DOC 51

VVVJJ I ................ .... I ............................... I 

"te44 

te46 

te48 -----

tes 1 ---------- --- L -- -

,,,

580 

560 

540 

520 

500 

480 

460

0

590 

580 

570 

560 

550 

540 

530

te44 . te46 

te48 ---- 

"tesl ........... 

.o°°°'-----------

•o°..~o*°°'°°•U97

0

KFKI AEK1 CAMP

VVV _
T17TTL'UT A T7

xxx mCAMP 

PMK-2 CAMP EXPERIMENT 

Fig. 4.20 SG Secondary Temperatures at Hot Collector 

Temperature 55 (K) 

-- - - _--

540 ... te82 •-- 

520 

510 

5e0 

490 

488 

53--------- t8------... 

470s2...... 

0 500 1000 1500 2000 2500 3000 3500 

Time (s) 

PMK-2 CAMP EXPERIMENT 

Fig. 4.20z SG Secondary Temperatures at Hot Collector 

Temperature (K) 

542 . .. • ., . •t e 8 0 

540 te82 ,, t ,, .-. • • % te84 - - - : 

538 ,..<• • ••" \tes2 

538 

536 

534 

532 , *'• b';". ,," _ 

530 

0 200 400 600 800 1000 1200 

Time (s) 

CAMPNRC.DOC

52
KFKIAEKICAMP

PMK-2 CAMP EXPERIMENT 

Fig. 4.21 SG Secondary Temperatures in Axis 

Temperature (K) 550 . . .. . . . . . . i . . . . i . . . . , 

540 te85 

530 te87 : 

530 ~~~tes2-----

520 

510 

500 

490 

480 

470 

4 60 . . .. . . . . . . , . . . , . . , , , , , , , 

0 500 1000 1500 2000 2500 3000 3500 

Time (s) 

PMK-2 CAMP EXPERIMENT 

Fig. 4.21z SG Secondary Temperatures in Axis 

Temperature (K) 

542 -i ..o ' te83 54 . . •te85 - -

540 S....... "te87 538 53 tes2 *t 

536 ¢

534 ,g 

532 o.1 . ... _1. 

530 

528 . . . . . . . . . . . . . . 

0 200 400 600 800 1000 1200 

Time (s) 

CAMPNRC.DOC

KFKI AEKI CAMP

:).5
KFKI AEA NAMP

PMK-2 CAMP EXPERIMENT

Fig. 4.22 SG Secondary Temperatures at Cold Collector

Temperature (K) 

550 r.--

0 500 1000 1500 2000 2500 3000 

Time (s)

PMK-2

3500

CAMP EXPERIMENT

Fig. 4.22z SG Secondary Temperatures at Cold Collector

Temperature (K) 

542 r200 400 600 800 1000 1200 

Time (s)

CAMPNRC.DOC

54

540 

530 

520 

510 

500 

490 

480 

470 

460

540 

538 

536 

534 

532 

530 

528

0

KFKI AEKI S.IK .l• AKJ.
KFKIAEKICAMP

PMK-2 CAMP EXPERIMENT 

Fig. 4.23 Temperature in Surge Line 

Temperature (K) 

600 . ............... . * . te70 

580 tes1 

560 

540 

520 

500 

480 

4 6 0 . ' . ' . ' . . .i . . . . . , . , . , 0 500 1000 1500 2000 2500 3000 3500 

Time (s) 

PMK-2 CAMP EXPERIMENT 

Fig. 4.23z Temperature in Surge Line 

Temperature (K) 

600 

te7O 

590 tesi 

580 

570 

560 

550 

540 

530 

o 200 400 600 800 1000 1200

Time (s)

CAMPNRC.DOC 55

KFKI AEKI CAIVI'P
PMK-2 CAMP EXPERIMENT

Fig. 4.24 Cold Leg Mass Flow Rate

Mass Flow (kg/s) A C

1500 2000

fl53 

fl54

I I..III.I I 11.11 I

2500 I I h ,, 1 1 " IIl 1 k 1, A

3000 3500

Time (s)

PMK-2 CAMP EXPERIMENT

Fig. 4.24z Cold Leg Mass Flow Rate

Mass Flow (kg/s) 

4.5 .--i ,

200 400 600 800 1000 

Time (s)

KFKI AEKI

"9..- I"

CAM41

4 

3.5 

3 

2.5 

2 

1.5 

1

0.5 

0 iLl. .1

0 500 1000

4 

3.5 

3 

2.5 

2 

1.5 

1 

0.5 

0

0

CAMPNRC.DOC

1200

L L I

#•AMP

I I

p'l

S. ... I. . .
KFKIAEKICAMP

PMK-2 CAMP EXPERIMENT

Fig. 4.25 Break Flow

Flow Rate (kg/s) 

0.14 ....

500 1000 1500 2000 2500 3000 3500 

Time (s)

PMK-2 CAMP EXPERIMENT

Fig. 4.25z Break Flow

Flow Rate (kg/s) 

0.14 ,r , ,

0 200 400 600 800 1000 

Time (s)

CAMPNRC.DOC 57

0.12 

0.1 

0.08 

0.06 

0.04 

0.02 

0

0

0.12 

0.1 

0.08 

0.06 

0.04 

0.02 

0

1200

K.FKI AEKI CAMP
KFKI AEKI CAMP

PMK-2 CAMP EXPERIMENT

Fig. 4.26 Break Outflow

mass (kg) 

140 L'

500 1000 1500 2000 2500 3000 3500 

Time (s)

PMK-2 CAMP EXPERIMENT

Fig. 4.26z Break Outflow

mass (kg) 

80 r--

200 400 600 800 1000 

Time (s)

CAMVPNRC.DOC

58

120 

100 

80 

60 

40 

20 

0

0

70 

60 

50 

40 

30 

20 

10 

0

0 1200
KFKI AEKI CAMP

PMK-2 CAMP EXPERIMENT 

Fig. 4.27 BRU-A Pressure

mass (kg) 

0.22 r

500 1000 1500 2000 2500 3000

PMK-2

3500

Time (s) 

CAMP EXPERIMENT

Fig. 4.27z BRU-A Pressure

mass (kg) 

0.22 r0 200 400 600 800 1000 

Time (s)

1200

CAMPNRC.DOC 

59

0.2 

0.18 

0.16 

0.14 

0.12 

0.1 

0.08

0

0.2 

0.18 

0.16 

0.14 

0.12 

0.1 

0.08

KFKI AEKI CAMP
KFKI AEK CA/UD

Flow Rate (kg/s) 

0.12 

0.1 

0.08 

0.06 

0.04 

0.02 

0 

0

PMK-2 CAMP EXPERIMENT 

Fig. 4.28 BRU-A Flow

500 1000 1500 2000 2500 3000 

Time (s)

PMK-2 CAMP EXPERIMENT

Fig. 4.28z BRU-A Flow

Flow Rate (kg/s) 

0.12 r--- ,

200 400 600 800 1000 

Time (s)

CAMPNRC.DOC 60

3500

0.1 

0.08 

0.06 

0.04 

0.02 

0

0 1200

KFKI AEKI
KFKI AEKI CAMP

PMK-2 CAMP EXPERIMENT

Fig. 4.29 BRU-A Outflow

mass (kg) 

120 r500 1000 1500 2000 2500 3000 

Time (s)

PMK-2 CAMP EXPERIMENT

Fig. 4.29z BRU-A Outflow

200 400 600 800 1000 

Time (s)

CAMPNRC.DOC 

61

100 

80 

60 

40 

20 

0

0 3500

mass (kg) 

9 c'.

8 

7 

6 

5 

4 

3 

2 

1 

0

0 1200

KFKI AEKI CAMP

CAMPNRC.DOC 61
KFKIAEKICAMP

Power (W) 

700 

600 

500 

400 

300 

200 

100 

0 

0

PMK-2 CAMP EXPERIMENT 

Fig. 4.30 Reactor Power

I . . . . I . . . . I . . . .- I

500 1000 1500 2000 

Time (s)

2500 3000

PMK-2 CAMP EXPERIMENT 

Fig. 4.30z Reactor Power

Power (W) 

700 , 

600 

500 

400 

300 

200 

100 

0

0 200 400 600 800 1000 

Time (s)

CAMPNRC.DOC 62

pwol

3500

1200

, . . ., , a I , i , i , , , , , I I , , I ! , , , I , , , , I

KFKI AEKI CAMP

! I g
KFKIAEKICAMP

PMK-2 CAMP EXPERIMENT 

Fig. 4.31 Levels in the Vessel

m)

0 200 400 600 800 1000 1200 1400 1600 1800

Time (s)

PMK-2 CAMP EXPERIMENT

Fig. 4.32 Levels in the Vessel

Level (m) 

9 c--

0 200 400 600 800 1000 

Time (s)

1200 1400 1600

CAMPNRC.DOC 

63

Level (i 

8.5 

8 

7.5 

7 

6.5 

6 

5.5 

5 

4.5 

4 

3.5

. ,q 7i , .1 . i . , , . , Ii . , I • ... le21 : 

---,,X.' le23 . . . .

S__. lv22 .......- .-- --v21 • 

M .. . .. ... .. . ...... .. . .. ..•• ,, w.. • ,, ;j 

..-. - -. .- . - -- . .- -- . - . ------ . . . . . - -- . . -- . - . . . . . .

8 

7 

6 

5 

4 

3 

2

1800

63

. . . . . . . . . . ~~~~, . . . . . . . . . I I I 1|,| |2!

KFKI AEKI CAMP

CAMPNRC.DOC
CAMP EXPERIMENT

Fig. 4.33 Hot Leg Loop Seal Level

Level (m) 

6.4 P0 200 400 600 800 1000 1200 1400 1600 1800 

Time (s)

PMK-2 CAMP EXPERIMENT

Fig. 4.34 SG Hot Collector Level

Level (m) 

8.5 E7

0 200 400 600 800 1000 1200 1400 1600 1800 

Time (s)

CAMPNRC.DOC 64

KFKI AEKI

PMK-2

~A xAp

6.2 

6 

5.8 

5.6 

5.4 

5.2 

5 

4.8 

4.6

8 

7.5 

7 

6.5 

6 

5.5 

5 

4.5

•AMP
KFKI AEKI CAMP

PMK-2 CAMP EXPERIMENT

Fig. 4.35 SG Cold Collector Levels

Level (m)

9 

8 

7 

6 

5 

4 

3

PMK-2 CAMP EXPERIMENT

Fig. 4.36 Cold Leg Levels

Level (m) 

6 --

0 200 400 600 800 1000 1200 1400 1600 1800 

Time (s)

CAMPNRC.DOC

le46 

le51 

lv42 

lv51 ----------

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

0 200 400 600 800 1000 1200 1400 1600 1800 

Time (s)

5.5 

5 

4.5 

4 

3.5 

3

KFKI AEKI CAMP

65
PMK-2 CAMP EXPERIMENT

Fig. 4.37 Pressurizer and Surge Line Level 

n)

0 200 400 600 800 1000 

Time (s)

1200 1400 1600 1800

PMK-2 CAMP EXPERIMENT 

Fig. 4.38 Primary Pressure

Pressure (MPa) 

14 , , .. .

0 500 1000 1500 2000 2500 3000 

Time (s)

CAMPNRC.DOC

66

KFKI AEKI

I

d- A AAA3

Level ( 

9

8.5 

8 

7.5 

7 

6.5 

6 

5.5 

5

I I - ' I I T I I le71 

le72 

lI I 

• 

I/ I 

/I I 

"1I l I11 

7T I --- I----

-- -I _. .. .. ., I, I 

, , I , , , , I , , , , I , , , , I , , , I , , , . I , I , , , I , , , I

12 

10 

8 

6 

4 

2 

0

3500

C' A N/fD
KFKIAEKICAMP

PMK-2 CAMP EXPERIMENT

Fig. 4.39 Down-comer Temperature

Temperature (K) 

560

0 500 1000 1500 2000 2500 3000 3500 

Time (s)

PMK-2 CAMP EXPERIMENT

Fig. 4.40 Cladding Temperature

Temperature (K) 

750

0 500 1000 1500 2000 2500 3000 3500 

Time (s)

CAMPNRC.DOC 67

520 

500 

480 

460 

440 

420 

400 

380

700 

650 

600 

550 

500 

450

KFK1 AEKI CAMP
KEKIAEKICAMP

APPENDIX

CAMPNRC.DOC

2

68

KFKI AEKI • A]•[P
KFKI AEKI

Fig 6.1 Primary Pressure

14 

12 

-. 10 

0~ 

CU 13_ 

0

Zn 6 

Uf) 

CO. 0k- 4 

2 

0 

5.5 

5 

4.5 

0 4 

-3.5 

a)2.5 

2 

1.5 

1

Fig 6.2 Secondary Pressure

CAMPNRC.DOC 69

CAMP

I I I U ca Ic. 

SPR21 exp - -

- - - I 

------ ----------- i---4------ ---- F--------I----F-

- - - - -

I I F F 

F I I I F F 

SI I I I 

l I I 

F I F 

__I F F I t 

I I 

1 F I 

* F I I I 

I I [ I 

I I I -1-

I I I I 

F I I F I II 

* IFIII I I 

* I I F I I I I

0 500 1000 1500 2000 

Time (s)

2500 3000 3500

SG calc. ---- _ --,-__ - . R 8 1 e x p 

-,..-t.-I~ --- - . - -.. .- -_ - -! -............ . . . -- . 

•\ I I I 

I\ I I I 

I[II \II I I 

II]I \II I I 

Il I \II F 

I I F I I F 

I I ' .I I I I 

F I I F 

-- I- - - - - - - - - - - --- - - --- - - .-. - .- -- .- . . - . . . . . "- - - - - - r " 

I TI - - - - III II II 

I xI I I " 

I I F I I 

F I 

I I I I I I 

I I I II I I I 

I F I II I I

I I I 

- - - - - - - - - - - - - - - - - "--- - - "

I I F I I 

I FFI I .F I 

I IIF I I 

I I FI I 

I I . . . I .. I F. . .. I . F

CAMP

0 500 1000 1500 2000 2500 3000 3500 

Time (s)
KFKI AEKI CAMP

Fig 6.3 Break Mass Flow Rate

0.14 

0.12 

0.1 

-0.08 

0.06 

0 

LL0.04 

0.02 

0

0 500 1000 1500 2000 2500 3000 3500 

Time (s) 

Fig 6.4 Integrated Break Mass Flow

r I calc M 01 exp -- SJE

120 -.. -:E -n ----- O -- 

.100 

80 ,--- -- - -- - ---

40~ 

2. I I i 

i I I Ii 

0 500 1000 1500 2000 2500 3000 3500 

Time (s)

CAMPNRC.DOC

70

lAn

Ile 

CD 

oý 

U..

KFKI AEKI CAMPIL.I

V
KFKI AEKI

700 

600 

500 

3300 

200 

100 

0

CAMP

Fig 6.5 Core Energy 

3'core calc. 

," ,PW0v 1 exp . ------ -------------- 3-

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

3 I 3I I 

I 3 3 3 

i/I I 

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

- ----------------------. . I 

I 3I I I I 

ii I i 

333I 3 I I I 

3 . . . . . .3 . . . . . . . . 3J. 3.I --- -- . . . . . 

50 0010 200 2500

0 500 1000 1500 2000 2500 

Time (s) 

Fig 6.6 Primary Mass Flow

3000 3500

4.5 

4 

3.5 

- 3 

2.5 

o 2 

U

cn 1.5 

CD, 

S1 

0.5 

0 

-0.5

0 500 1000 1500 2000 2500 3000 3500 

Time (s)

CAMPNRC.DOC 

71

--------------------------- c------eexp.-- ,, FL54 exp. 

-- - - - - - ii-- - _- - - - - - - - - -

- -I-- I --

3 I 3 7 

3 3 3 3 

I 3I 

3I 3 

- . . . . . . . . . . . . . . . . 3' . . . . .3.. . . -3.. . . .i . . . .

3I 3 I3 

I I3 

I I I I 

3 I I I

CAMP

CAMPNR.C.DOC 71
KFKI AEKICAMhP

Fig 6.7 Hydroaccumulator Pressure

6.5 

6 

5.5 

S5 

2 4.5 cn 

(I,,- 4 

0 3.5 

3 

2.5 

2 

10 

9.8 

9.6 

9.4 

E 9.2 

> 9 

8.8 

8.6 

8.4 

8.2

A' 

'I

: 

N 

V

-T-i

3000 3500

Fig 6.8 Hydroaccumulator Level

' ' ' 7 SIT ,caIc. 

....... T- - -. - - -. - --. --- . . - .- -- . -. - . L E 9 1 ex p .

LII. .. . .. . . . . I_ 

L A II .. . . I .. . . .I I

-- . . -.. - -.. -... --... - - -.. . - . i- _ ..... -- -........ - _

A I i 'I I 

I.i, * i' 

IlIt I I •-- .. ----- .. . .. .. . -- - -. . - .- -- .-. . . . . . . -r - - . . . .. -------- . . . .

0 500 1000 1500 2000 

Time (s)

CAMPNRC.DOC

72

0

exp

2500 3000 3500

. i 1 

KFKI AEKI i"• A 1Vlp

500 1000 1500 2000 2500 

Time (s)

I 

ii
KFKI AEKI

Fig 6.9 Steam Dump Mass Flow

0.12 

0.1 

-,0.08 

o0.06 

00.04 

LL 

0.02 

0

9 

8.5 

8 

7.5 

E 7 

>6.5 

6 

5.5 

5 

4.5

0

BRU-A'calc bleed calc. IhI i I ----- \ :L02 exp---- I i 

III I - -------- - - - - - -

III r I I 

I II 

I i i 

II II r I i ----- --------- - --- -----------

I I I I I 

I I I I 

I I I 

I I I -I- - ------------ - - -- --- -- -- - I--

- - -

I I 

I I SI - 100 -+,I 10 nI500IIn 00 20 3000n 3500 I

500 1000 1500 2000 2500 3000 3500 

Time (s) 

Fig 6.10 Pressurizer Collapsed Level

0 500 1000 1500 2000 2500 3000 3500 

Time (s)

CAMPNRC.DOC

CAMP

PRZ calc. I I . . ..

------- - ------------- ---------- --------- LE71 exp. u eca~c. 

------ ly ------ • ----------------------- 7 -- - - 1- - - - - - - -7- - - - -I- - - - -r 

II I III 

Il !, I I I I' I 

---- 1-- ----- ---- --- ------------ I - I -- -- - - I I .. 'r. I..1 - - --- • I• 

I I J I I I I I I 

I iII I I lI 

IIII I I 

SI I 

"-I'I I I

73
KFKI AEKI CAMP

Collapsed Level in Reactor Vessel

RV calc. 

LE11 exp. i I 

iI

9 

8 

7 

E6 

>D5 -J 

4 

3 

2

1000 1500 2000 2500 3000 3500 

Time (s) 

Fig 6.12 Primary Mass Inventory

K

- i

primary caic. 

- -I-- - - - - - - - - - - - - -

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

0 500 1000 1500 2000 2500 3000 3500 

Time (s)

CAMPNRC.DOC

74

Fig 6.11

'4

I 

L 

r 2

K'

IA

0 500

140 

130 

120 

•100 

90

70 '

60

- f 

1 

I 

)

4-

I 

I 

I 

I 

-4--

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

-

72:l
KFKI AEKI

8.5 

8 

7.5 

-• 7 E 

"-56.5 

--J 6 

5.5 

5 

4.5

Fig 6.13 Collapsed Levels in Hot Leg Loop Seal 

S, , RV side calc. 

- - ------------ -------- LE31 exp 

----- SG side calc. 

LE45 exp --_

-- I-I -I I -- I -- -I 

II II I 

- f - - -- . . . -. - -.. -. -.. -. - . . -.- . . . . .- - - - .-r -. - - -.. -. -.. . i- 

--- ---- -• - -• -. T .-- - -. .-- . -. .- .-. - . . . . . . . . -- . . . . . .

- - - - - - - - ---- - - - - ISI I II I 

-- ------ •,- . -)- . 

I I I 

I I IIi' 

II tI I II

500 1000 1500 2000 2500 

Time (s)

0 3000 3500

Fig 6.14 Collapsed Levels in Cold Leg Loop Seal 

,S side calc. I I 

------ ------------- - - - - LE 6 e p ""RV side calc. 

II LE52 exp I \I II 

I I I I I I 

... -. - -' -, - ,-

I I I I 

I I I I 

I II I I 

I I II 

........ -..... i-I-- - -- I-

. . . I. \I" II If 

I I I 

II II 

. . . .- III "I 

I I 

II I I - I 

III I I 

I I IIII 

II I I I I 

III I I I I

0 500 1000 1500 2000 

Time (s)

2500 3000 3500

CAMPNRC.DOC

CAMP

9 

8 

7 

E 6 

4 

3 

2

CAMP

75
KFKI AEKI CAMP

Fig 6.15 Down Comer Temperature

* II 

F - --- 1

: DC 

--------- T EC -

calc. 

1 exp. ,

F L 

-F - - - -F

'-3 

-- I F;• F 

4

0 500 1000 1500 2000 2500 3000 3500

0 500 1000 1500 2000 2500 3000 3500 

Time (s) 

Fig 6.16 Core Inlet Temperature

S...., , inlet calc. F F F _TE63 exp. 

F - - - r -- F

I -

I''

0 500 1000 1500 2000 2500 3000 3500 

Time (s)

CAMPNRC.DOC 76

560 

540 

520

a 

4

E

-500k 

'480 .. 

)460 

5440• 

420

400

%ou

560 

540 

.520 

a50 0 

c480 a) 

E460 

-4 4 0 

420 

400

i • , ,

i ] I

t I

I 

I 

I 

---- I. 

I
600 

580 

2560 "1-4 

a) 

5540 

a520 

E 

F'500 

480 

460 0 500 1000 1500 2000 2500 3000 350( 

Time (s) 

Fig 6.18 Collapsed Level in SG Secondary Side

0 500 1000 1500 2000 

Time (s)

2500 3000 3500

CAMPNRC.DOC 

77

KFKI AEKI CAMP

Fig 6.17 Core Outlet Temperature 

!" " fluid calc. I I I I ,I ,I I , steam calc. 

. --------------- .. ---------- TE22 exp - I I I 

I 

-- --- ----- 4--- -----4------------ ------------

I I I - - - -

I I II 

II II I I 

III•I I I 

0 5 1 1 2000 2 3 350

-I L - - -------------- IL - -

)

8.6 

8.4 

8.2 

E 

-J8 

7.8 

7.6 

7.4

I 4 ! SG calc. 

,1 :LE81 exp. I I 

III I 

IIII I 

I-- -I 

I 

IIII I 

IIII I 

.................-- - - - ---- - - -

III I 

I I 

*iII 

I 

III III 

I I I I 

II I I 

I-II I I 

II1 I I 

I I I II 

- IIII I I% 

S, . 

II I I. 

I I I 

II i i , , ] i , i I , , , , I

CAMPNRC.DOC 77
KFKJ EKI A 1ASP

Fig 6.19 Cladding Temperatures at 3 m

0 500 1000 1500 2000 2500 3000 3500 

Time (s)

Fig 6.20 Cladding Temperatures Top

- - ----- - - -, 

__ i 

2'-

I: 

Fi I

hot rod top calc. 

TE 17 exp. 

TEl9 exp. 

- ------ -- -4- - - - I-- 

I 

i - - - - -

I 

I I

2

0 500 1000 1500 2000 2500 3000 3500 

Time (s) 

CAMPNRC.DOC '78

680 

660 

640 

2620 

'¥600 

2580 

-560 

E540 a) 1-5 2 0 

500 

480 

460

750 

700 

---650 •a,5 

C600 

9550 

500 

450

KFKI AEKI •A MP
KFKL EKI AMP

Fig 7.1 Steam Dump Mass Flow

0.12 

0.1 

o.08 .-0 

.- a• 

tq0.06 -

o20.04 LL 

0.02 

0

400 600 800

F

1000 

Time (s)

1200 1400 1600

Fig 7.2 Secondary Pressure

600 800 1000 

Time (s)

1200 1400

CAMPNRC.DOC 

79

5.4 

5.3 

5.2 

,5.1 

- 5 

"-4.9 

•4.8 

64.7 

a.-4.6 

4.5 

4.4 

4.3

I I I 

- I I 

-- t- ---- --------- 4-----4---

I I . . _ - - -

I I 

I I I 

t ~r 1 

S- - I I 4 

PR81 exp. 

-.calc. dt=0.1 

calc. dt=0.05 -,

--calc. dt=0.01 - -

F calc. dt=0.001 - .

400 1600

FLO2 exp._ calc. dt=0.1 ----- calc. dt=0.05 - _ calc. dt=0.01 . calc. dt=0.001 - ,_ ...... . ,eed calc. - - - --- - . . -- . . . . 

ii: 

IT -------- . . . i . . -. -. . . . -. 

. . . . . . . . . . . . . . . . . . . . . .

KFKI AEKI CAMP

-~~~~ -. ~~ ~ -. - - - .-- . ..- 
Fig 7.3 Collapsed Level in Reactor Vessel

5 • ---; . .- •--- " 

3.5 - -'

2.45 LE 1 exp. caic. dt=0. 1 

2 calc. dt=0.05 caic. dt=0.01 

.calc. dt0.001~

400 600 800 1000 

Time (s)

1200 1400

Fig 7.4 Cladding Temperature

TE19 exp. calc. dt=O.1 

calc. dt=0.05 

calc. dt=0.01 

calc. dt=0.001 

- i - - - - -

I F 

-- -

I I -i 

V I

0 1000 -" --110 -: 103• -------- ----140 --- - -- 1500 ' .. . -,-_ 1600 

I II I 

0O 1000 1100 1200 1300 1400 1500 1600

Time (s)

CAMPNRC.DOC 

80

KFKI AEKI

6 

5.5

CAMP

E

I,;u

8501 

800-

1600

I

2-750 

-700 

-I.

0_650 

E -) J-600

550 

500 

9(

I 

[

I 

t

L !
Fig 7.5 Steam Dump Mass Flow

0.12 

0.1 

"--0.08 

"C0.06 

ý20.04 

U

0.02 

0

400 600

FL02 exp. calc. dt=0.05 

.calc. dt=0.02 

calc. dl l0.01 

bleed calc. 

-4-- -.-.

I ' I 

I I 

I II 

I Ii 

I I I I 

I I I I 

I II I 

I I i i 

I I I 

I I I 

I I i I 

I I I I 

I I I I 

I i 

I I I 

I I I 

I I I 

- k - - IJ 

800

N 

II 

-l 

LLhk

1000 

Time (s)

1200 1400

Fig 7.6 Collapsed Level in Reactor Vessel

6 

5.5 

5 

4.5 

E 4 g4 

>3.5 _J 

3 

2.5 

2 

1.5

. ...LE11 exp. calc. dt=0.05 , calc. dt=-.02 -- calc. dt=0.01 

I 

- -- -- II - - - - - I - - - - - -4-- -- - - ----- - - -

ti I 

I I 

I--4I 

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

\ I: I!I 

- - - I 

- -I - - - - - -

400 600 800 1000 

Time (s)

CAMPNRC.DOC

1200

81

KFKI AEKI CAMP

II 

SI I 

i I Ž - - 4 

II 

I I I 

IIi I 

II I I 

I I .

IIi I 

I I I I 

II I I 

____ ________ l 

- __ I ___

1600

1400 1600

AMP

i. ~ i I i l ll.l
KFKI AEKI CAMP 

Fig 7.7 Cladding Temperature 

850 TEl9ex 

caic. dt=0.05T 

800k caic. dt=0.02 - -~ ----- ----- - ----

calc. dt=0.01 --

"=700K - ------ I 

-------- -- ,--------- 

-700r -- - -- - -- -- - - ----.

~L 

550 ------------------------ -------- L4._ 

5 0 0 F 

900 1000 1100 1200 1300 1400 1500 1600 

Time (s) 

Fig 7.8 Steam Dump Mass Flow 

0.12k FL02 exp. __ 

IIcaic. HTC= 6 - j 

0.1r - --- i-----------------I--- ----- calc. HTC=8 cabc. HTC=10 Icalc. HTC=12 ---

-- - - abc. HTC=15 -

- - - - - - - - _ - - - - - - -_ - -i -60.08 -_ -_ j* 1 - - ~- _i- 60 - aIMI 

- - - - - - - - - - T - - - - -

- 0.04 -------- 1--

0.02 F--------

400 600 800 1000 1200 1400 1600 

Time (s) 

CAMPNRC-DOC

82
KFKI AEKI CAMP 

Fig 7.9 Secondary Pressure 

5.4 , , 

In I+ 

5.2I 

cII I 

CII I I 

CD) 

|l III I I I I 

S4.6 .... I- PR81 exp. ------------- - ----

nalc. HTC= 6 

calc. HTC= 8 

4.4 -.-.calc. HTC=10 - - 6alc. HTC=1 2

Palc. HTC=1 5 --.- . 4.2 

400 600 800 1000 1200 1400 1600 

Time (s) 

Fig 7.10 Collapsed Level in CLLS SG Side 

LE46'exp. ' calc. HTC= 6 

8.-- calc. HTC=1 0 -

calc. HTC=12 7 .,-calc. HTC=15 -

E 

7.. . --- . - - - - - - - - - -4- 

3 ... . . .4 . . . .. J. . . . . . .I . . .. " 

• \ III "t I 

II 

400 600 800 1000 1200 1400 1600 

Time (s)

CAMPNRC.DOC 83
KFKI AEKI CAMP 

Fig 7.11 Collapsed Level in CLLS Vessel Side 

48--------- ' ' calc LE52 HTC_ exp. 8 

4.8 

4 --- .6 -- --- -- -- -- -- ---- -- -- --- -----.. 

-34.42- --- -- -- 2 L4 7 

' -- -.... I. -- x 

I I ----- i --- I 

- - - - - - - - - -I - - - - - - - - --- - - -I - - - - - - - - -

4 -i . . . . .e4 

7 --- - - - - - -- r _ 

3.8 6- - ------- I " - - - - - - . . . . . . . . . . . . . . . - . . . . . . -.- - - -.. --- 

3.4 

400 600 800 1000 1200 1400 1600 

Time (s) 

Fig 7.12 Collapsed Level in Reactor Vessel 

- Ii 

2 .5 -- -- ----

2 

400 600 800 1000 1200 1400 1600 

Time (s) 

CAMPNRC.DOC 84
KFKL AEKI CAMP

0.7 

0.6 

0.5 

o 0.4 

-0.3 

-0.2 

-o 0.1 co 

S0 

-0.1 

-0.2 

-0.3

800 1000 

Time (s)

1200 1400 1600

Fig 7.14 Cladding Temperature

750 

700 c• 

00C, 

Vc 

2650 

ICU 

550 -

500

900 1000 1100 1200 1300 

Time (s)

1400 1500 1600

CAMPNRC.DOC 85

Fig 7.13 Primary Mass Flow 

I FL54 exp._ SI I 

---- ---------- ---- calc. HTC= 8 ,a ,, c , •= 1 2 --

I I I L - - - - - - - - - - - - - -- I 

I II 

i n I 

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

" - -

ii 

- i I I

400 600

KFK[ AEKI CAMP
Fig 7.15 Break Mass Flow

0.14 

0.12 

cn"0. 1 

";0.08 

u--0.06 

E0.04 4

0.02 

0 

0 

0.12 

0.1 --

"(n?..080 

z-4--0.06 

o0.04 1 

0.02 

0 

400

- I 

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

FLO1 

calc. 

--caic.

exp. 

0.90 - --- H 

-I

J%.I

200 400 600 800 

Time (s)

1000 1200 1400 1600

Fig 7.16 Steam Dump Mass Flow

600 800 1000 1200 1400 1600

Time (s) 

CAMPNRC.DOC 

86

KFKI AEKI

CA A~fD '-- rI1

l-•i-• ±VII-
KFKI AEKI CAMP

Fig 7.17 Secondary Pressure

5.4 

5.3 

5.2 

,5.1 

n 5 

"-4.9 

S4.8 

o4.7 CL. 4.6 

4.5 

4.4 

4.3 

6 

5.5 

5 

-. 4.5 

-a 4 

S3.5 

3 

2.5 

2

400 600 800 1000 

Time (s)

Fig 7.18 Collapsed Level in Reactor Vessel

400 600 800

CAMPNRC.DOC

1000 

Time (s)

87

, " . -1• -f -.. -,, .-.. .--_ , 

.. ......---- - t/ , . . •, ----.-- -

. . - - -- - -- - - I II 

-- - - - - 4 - - - - - - - - - - - r I - - - - - - - - - I I 

I I 

I I I 

I II 

I I 

-- - -- - -- - -- - L ---------- L -------- L... .. 

PR81'ex., 

-caic. 0.85 - - calc. 0.90 - I - . , I . . . 

-- - ---- --- --- - -- - -- - - - - L - - - - - - - - L - - - - - - - - - - - - - - -

1200 1400 1600

• ' I I I 

I I I 

I I I 

I II 

-- -r -r ----

I I I SI i 

I I 

--- -- -- - r-- -- - - - -- - - - - - - -- - - -

I II 

* I 

I' I 

I I 

LE1 1' 'exp. '"' 

----------.. calc. 0.85 - , • • , Im I• ,,',, 

calc. L1... 0.90 - \-,-, 

-.--, - -- -- -- -- -- - - -4,F 

1200 1400 1600

KFKI AEKI CAMP
KFKIAEKICAMP

Fig 7.19 Collapsed Level in CLLS SG Side

9 

8 

7 

3 

5 

4 

3

Time (s)

Fig 7.20 Collapsed Level in CLLS Vessel Side

LE i ca

4 .8 . . . . -- -

E -

- 3, 

lr1-

32-exp. 

,Ic. 0.85 

LIc. 0.90

I I

400 600 800 1000 1200 1400

Time (s)

CAMPNRC.DOC

88

400 600 800 1000 1200 1400 1600

4.6 

w-4 .

4 

A 0

_J 4 -------I ~t~i 

3.8

3.6

3.4

1600

I

KFKI AEKI CAMP

-r,,,, o'•

I 

! 

I 

I 

,I

- - -- - - - - -T -

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

"- --- - -

I

I
KFKI AEKI CAMP

Fig 7.21 Primary Mass Flow

0.7 - I I

0.6 

0.5 

0.4 

0.3 

0.2 

0.1 

0 

-0.1 

-0.2 

-0.3

400 600 800 1000 

Time (s)

1200 1400 1600

Fig 7.22 Cladding Temperature

750 

700 

.e650 

=3 

I0600 

550 

500

900 1000 1100 1200 1300 

Time (s)

1400 1500 1600

CAMPNRC.DOC 89

0) 

U,

I I -L54 exp_ ---- -- r-------- --- ----------- calc. 0.85 , calc. 0.90 

---------------- ------ ------ --------- -- - - - -7_ P- - - - -- ---------------- I -- - -

I 

, ! , , ,I , ,I , 

.-..- ,-- -..-.. _ . ..- .... , --. ---, -, ---., .-.---, .. . III , 1, 1: I II 

- - - -- -- I - --- - - - - l- - - --

- - - -- -i - - -I 

\ I"4- - - - - - - - - - - - - - -L - - - - - ---,-,-, _"',__,,_,_

KFKI AEK1 CAMP
NRC FORM 335 U.S. NUCLEAR REGULATORY COMMISSION 1. REPORT NUMBER 

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

NRCM 1102, and Addendum Numbers, if any.) 

3201,3202 BIBLIOGRAPHIC DATA SHEET 

(See instructions on the reverse) 

2. TITLE AND SUBTITLE NUREG/IA-0201 

Description and RELAP5 Assessment of the PMK-2 CAMP-CLB Experiment 3. DATE REPORT PUBLISHED 

2% Cold Leg Break Without HPIS With Secondary Bleed MONTH YEAR 

March 2001 

4. FIN OR GRANT NUMBER 

5. AUTHOR(S) 6. TYPE OF REPORT 

L. Pemeczky, G. Baranyai, A. Guba, Gy. Ezsol, I. Toth 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.) 

KFKI Atomic Energy Research Institute 

P.O. Box 49 

H-1 525 Budapest, Hungary

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 Systems Analysis and Regulatory Effectiveness 

Office of Nuclear Regulatory Research 

U.S. Nuclear Regulatory Commission 

Washington, DC 20555-0001 

10. SUPPLEMENTARY NOTES 

11. ABSTRACT (200 words or less) 

There is a general interest to validate best estimate (BE) reactor safety system codes for WER-type reactors. The 

OECD-WER code validation matrix is used for the selection of tests in support of accident management (AM) and to eliminate 

"white spots" in the matrix. Based on this matrix - test types not yet covered - a proposal was made at the 12th (Spring '98) 

CAMP meeting in Ankara: 

* perform WER-440/213 related experiment on the Hungarian PMK-2 test facility 

* validate RELAP5/mod 3.2 code. 

The CAMP-CLB test is an AM-type experiment with small leak in the primary coolant system needing secondary side heat 

removal. The break size is 2%, heat removed by break is insufficient to depressurize primary circuit below secondary pressure. 

Steam dump valve to atmosphere regulates secondary pressure until - as an AM action - secondary bleed is started following 

core fuel rod simulator overheating which is a consequence of unavailability of the high pressure injection systems. 

Report presents a short description of the PMK-2 facility, the initial and boundary conditions of the test followed by an evaluation 

of the results by measured parameters. After reviewing modelling aspects and results of post-test calculations by 

RELAP5/mod3.2.2 Gamma a sensitivity study is described. The "bifurcation type" behaviour encountered in parametric studies 

could be the result of the code calculating by different constitutional models depending on the time step or secondary heat 

losses. This behaviour needs further investigation and it is reported as a new RELAP5 user problem.

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

RELAP5 unlimited 

PMK 14. SECURITY CLASSIFICATION 

Cold Leg Break (This Page) 

unclassified 

(This Report) 

unclassified 

15. NUMBER OF PAGES 

16. PRICE

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

Jn recycld• 

Fedr aRper 

Federal Recycling Program
UNITED STATES 

NUCLEAR REGULATORY COMMISSION 

WASHINGTON, DC 20555-0001 

OFFICIAL BUSINESS 

PENALTY FOR PRIVATE USE, $300