XA03006 06
TEST MODEL DESIGN FOR SEISMICEXPERIMENTAL TEST OF PWR
REACTOR COMPONENTS
Toshio IchikawaMitsubishi Heavy Industries, LTD, Japan
WORKSHOP ON"SEISMIC DESIGN ASSESSMENT BY EXPERIMENTAL METHODS"
NUCLEAR POWER INSTITUTE OF CHINA (NPIC)CHENGDU, CHINA, 10-14 SEPTEMBER 2001
KI ?
National W~orkshop on Seismic design assessment by experimental methods
NPIC - Chengdu
Test model designfor Seismic Experimental Test of PMR Reactor Components
Toshio IchikawaMitsubishi Heavy Industries, LTD
Japan1-1-1 Vadasaki-cho Hyogo-ku Kobe, 652-8585
toshio ichikawa~kind.kobe.mhi.co.jp
Table of Contents1. Introduction
2. Category of Seismic Test type in IAEA Safety Gulide2.1 A Method of seismic qualification2.2 Type of testing2.3 Required items of the seismic test qualification2.4 Test procedure and considerations
3. Number of mock-ups3.1 Fuel Assembly
a. Mechanical characteristics testb. Vibrating Characteristics testc. Seismic response proving test
3.2 Rector Internalsa. Mechanical characteristics testb. Scale model flow Vibration testc. Seismic proving test
3.3 CRD3M and Integrated Head Package seismic testa. CRDM Vibration Characteristics testb. Vibration Characteristics Test for CRDM &IH-Pc. Seismic Proving Test (integrity and the control rod drop test)
4. Scaling
5 Modeling design of Seismic Test5. 1 Seismic Test Model design of a CRDM-IHP115.2 Seismic Test Model design of a Reactor Internals
6 Location of Instruments and type of acquisition tools6.1 Shell structure6.2 Beam structure6.3 An experimental test of CRDM-IHP
7 Conclusion
1. IntroductionIf the integrity or functional capability of items cannot be demonstrated with a reasonable degree ofconfidence by analysis, the test is needed to verify or to assist in qualification.However, the seismic test that simulated the environment of the operation conditions of the actualplant and ageing effect are difficult, and it is common to use normal temperature and a scale model.
The soundness in the operation conditions of the system gives and evaluates load etc. at the time ofthe physical-properties value of model verified by the experimental test result, and operation. In thiscase, it is necessary to check the validity of the function of an analysis model and an analysis code.In the seismic design guide of IAEA(NS304), fundamental requirements and recommendationmatters are shown,' such as a kinds of test methods, selection of the scale of the evaluation methodby experimental test.
The experimental test method indicated by the ABA seismic design guide and its requir-ed matterare outlined first.Then an example of model design is shown with this lecture, and the point of view (number ofmock-ups, detailing, scaling, location of instruments, and type of acquisition tools) for a modeldesign is explained in this session.
2. Category of Seismic Test type in AEA Safety GuideA category division of the experimental test relevant to the seismic design specified to the IAEA Safety standard of designguide NS304 is introduced, and the experimental purpose and the view of selection of a method are explained.
2.1 A Method of seismic qualification501.* A mnethod, of direct seismic qualification of items is the testing of the actual item or prototype.
If the integrity or functional capability of an item cannot be demonstrated with a reasonable degree of confidence
by analysis, a test may be needed to prove or to assist directly or indirectly in qualifying the item.
(*: 501 is a paragraph number in a IAEA Safety standard of design guide NS304)
2.2 Type of testing502. Types of testing can be listed as follows:
*type approval test (fragility test)*acceptance test (proof test)*low impedance test (dynamic characteristic test)*code verification test
2- 1
2.3 Required items of the seismic test qualification
503. Test qualification of seismic category 1 and 3 items is required when failure modes cannot be identified or
defined by analysis or earthquake experience.
-Direct qualification by testing employs type approval and acceptance tests.- Low impedance (dynamic characteristic) tests are normally used to identify similarity or verify or
help develop analytical models.
- Code verification tests are used to develop generic verification of analytical procedures which typically
use computer codes.
The methods or testing depend on the required input, weight, size, configuration and operation characteristics of
the item, plus the characteristics of the available test facility.
Type approval and qualification acceptance tests require the availability of:
- Shaking table (one or more degrees of freedom)- Hydraulic actuator- Electric actuator- Mechanical actuator (unbalanced mass type)- Impact hammer blast
2 -2
Low impedance and code verification tests typically use;
- Electric actuator- Mechanical actuator (unbalanced mass type)- Impact hammer blast- Self-excitation or ambient vibration excitations.
2.4 Test procedure and considerationsThe procedure and the thing that should be taken into consideration shown in ABA par.504-512are explained.504. A meaningful test, performed with the purpose of assessing the integrity or functional capability of an item
requires that the conditions existing for this item in the plant during an earthquake are correctly or conservatively
simulated or that any departure from them will not significantly influence the result.
Among these conditions, the most important are:- input motions
- boundary (support) conditions- environmental conditions (e.g. pressure and temperature)- operational conditions (if functional capability has to be assessed)
2- 3
505. The concept of the testing procedure is based on subjecting the item to conservatively derived
test conditions in order to produce effects at least as severe as those of the design basis seismic event concurrent
with other applicable operating or design conditions.
506. The functional and integrity testing of complex items, such as control panels containing many
different devices, may be performed on the prototype of the item itself or on individual devices with seismic test
input scaled to allow for the location and attachment of the device within the item or on the item (via the in-cabinet
transfer function).
- 507. Account should be taken of such effects as radiation and ageing, or other conditions
which may cause deterioration or otherwise alter the characteristics of the item during its in-service life.
508. Low impedance (dynamic characteristic) tests are usually made on items in situ. Items are
typically tested by:
- Mechanical actuation- Impact
- BlastOther low energy exciters as well as ambient excitation. These tests cannot be used for direct seismic qualification
of the item but can be used to define dynamic, including support, characteristics which can then be used in analysis
2- 4
or other tests to qualify the item.
509. The type approval (fragility) test- Design margins to failure- Damage or non-linear response- Identification of the lower bound failure modeSuch testing is typically carried out by means of a shaking table.The fragility test is useful for ;
- Finding unexpected failure modes- Potential malfunctionsbecause the test conditions can cover a wider spectrum of loading than those required as a design basis.
510. The acceptance (proof) test is also used for electrical and mechanical components to demonstrate
seismic adequacy. It is typically performed by manufacturers to demonstrate compliance with procurement
specifications and does not give data relative to seismic design margins or failure modes.
Such testing is typically carried out by means of a shaking table.
511. The code verification test is important for reliable analytical work. Computer codes should be
verified before their application by using an adequate number of test results or results obtained from other
appropriate computer codes or analytical procedures. The use of a number of test results which cover the range of
interest and have been correlated with analytical results is strongly recommended.
2- 5
3 Number of mock-upsThe modeling range and the numbers of experimental test models change with kinds of
experimental test, like the validity of a seismic proving test, an analysis model, and an analysiscode are shown.Moreover, the modeling range, numbers, and a scale of model are restricted by the capability of
test equipment.Here, the following three items are explained as an experimental test relevant to the esi design
of reactor core internals structure. The following example as experimental test equipment whichchecks the validity of the;- Basic characteristic (stiffness, vibration characteristic) of equipment- Integrity or function of a reactor internals.- Seismic Analysis code and a models
Examples of seismic test model include followings.- Fuel assembly,
- Reactor internals,
- Control Rod Drive Mechanism (CRDM)
3.1- 1
3.1 Fuel AssemblyA experimental tests required for the seismic design of a fuiel assembly are to proof the integrityunder seismic condition,, and to verify the input of an analysis model and the function of ananalysis code.In an experimental test, the stiffness of a grid, and bending stiffness and vibration characteristicsof a fuel assembly are measured.Moreover, the effect on vibration characteristics of the core arrangement and the vibrationdirection, and the effect on the integrity at the time of an impact are measured.The experimental test relevant to the earthquake-proof design of a fuel bundle is shown in Fig.3.1-1.Here, The examples of an experimental test model are given by dividing into the following threeitems.
- Mechanical characteristics test- Vibration characteristics test- Seismic proving test
3.1-2
Low impedance Mechanical Characteristics Single Assembly
Stiffness of grids
Stiffness of Asseinbly
Rebounding coefficient and buckling load
Code verification Vibration test Vibration characteristics of assembly
Vibration characteristics of rodand assembly (BOL/EO L)
Row model Maximum rows of plant
Square model Actuated row direction
Actuated 45 degree direction
Approval & Seismic proving testAcceptance
Displacement (center/rimi)
Integrity and impact loads assembly
Fig 3.1-1 seismic test flow of fuel assembly
3.1-3
a. Mechanical characteristics testThe mechanical characteristics test relevant to a seismic design is carried out about the followingitem.
- Grid stiffness test;Test is performed by using a model of a actual fuel grid, test equipment and an photograph areshown in figure 3.1-2 and 3- Grid impact testThe dynamic stiffness and buckling load at the time of a grid collision are measured.Test equipment and an photograph of testing are shown in figure 3.1- 3 and 4- Fuel assembly impact testThe characteristics of the collision between grids or grid- baffle plate is measured, and testequipment outline is shown in figure 3.1- 6.
3.1 -4
* I' ~~Load 'L LiI Load 7
FL; -. ~~~~~~~~~Plt
~~~~lz~~~~i ''~~~~~ Fuel Gid
___ [I] ~~~~~~FuelRods
.. A.
Fig3.1-2 Model of Grid stiffness test
3.1-5
Fual Assembly Grid Test Equipment
Fig3.1-3 Outline of Grid stiffness test setup
3.1 -6
Pendum Arm
Load cell
Hunmmar
Regid Support ]Fuel Grid~
Fig3.1-4 Model and test equipment of Grid impact test test3.1- 7
Fig3.1-5 Outline of grid impact test setup
3.1-8
-- 4 ir~~~~~~~, -
F3~~~~~ K ~~~Initial displacement
F 2
- K~~3
__ Q ~~~Grid stiffness
/ I ________ ~S Rigid wall
F Load cell
1~~~~~ ~~Displacement1/777 2/-772
Fig3.1-6 Model and test equipment fuel assembly impact test
3.1-9
b. Vibrating Characteristics testA test for vibration characteristics test of a fuel assembly is performed to check the followings;Transverse direction of frequenciesDamping constantVibration mode shape.
- Vibration characteristics for a fuel assemblyFrequencies, mode shape and a damping constant for a transverse direction are measured by using aactual size of the fuel. assembly, a test equipment are shown in Fig. 3. 1-7. A test is carried out in airand under water conditions.Especially frequency and damping constant of 1 mode will be measured by free vibration test.Because they are depend on FA's displacement.
- Vibration characteristics in case of group vibrationVibration characteristics with impact each other in actual core. arrangement are more complicated.Seismic design analysis model is used as shown in Fig.3.1-8. The basic vibration characteristics aremeasure by using a scale model to simulate fuel vibration characteristics based on above tests.Outline of a Scale model is shown in Fig.3.1-9. This test model of the fuel assemblies is simplified
3.1-10
Upper Fuel Pin-
Displacement
Cable...
Actuator
Load Cell~!
7/7-~~~.
Lower Fuel Pin -
Fig 3.1-7 Fuel assembly transverse direction siffness test
3.1 - 11
II~~~~arn Na. ~ ~ ~ 1 d
p lelaiI 2 * I
ArACIDI. V~~j~f~bsC -
Upi-CO. Core Plait ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~flILII( I
I'llel Anmendily b~IarrtI
Schematic layout of the fuel assemblies in PWR Caluculational model for the colliding vibration of fuelassemblies
Fig3.1-8 Seismic analytical model of fuel assembly
3.1-12
Test Vessel -
I' ______________ ~ ~~~Oil Pressure_ _ _
Beam-Group ModelJ
Electric___ ___
-A I ~~~~~~~~~~~~~~~~~~~~~Apparatus. WaeI I j / I ~~~~~~~~~~~~~Input
C -~Manifold -
/~~~~ -
Vibrating Table Actuator
Fig. 3.1-9 Verification test modelwith considering the collision effect
3.1- 13
c. Seismic Response Proving TestThe actual reactor core consists of many fuel assemblies. It is necessary to verify an vibrationcharacteristics and integrity with considering of the influence of the number of arrangement, and thegap between fuel assemblies.The seismic proving test that is considered with group vibration and impact phenomenon betweenfuel assemblies should be performed using the fuel assembly of actual size. And it is necessary tocheck the oscillation characteristics of the number of arrangement of a fuel assembly, the directionof a sequence, and the direction of 45 degree etc.
-The seismic proving test of the reactor internals carried out by NIJPEC, world's largest 1 5x1I mshacking table (maximum loading capability 500t/G) was used in 1985.It was carried out using full size fuel assembly arrangements of maximum rows (1 5 rows x 3 lines)of a 4 loop PWR plant, and it is shown in figure 3. 1-10 .
-Although the design evaluation modeling was represented with the number of the maximum rows,since the validity was shown, 7 rows and the one line model (Fig. 3. 1-1 1), and the seven rowsmodel of seven lines (Fig. 3.1-12) were used.
-The direction of actuation of 45 degree was also performed again.
3.1-14
Test vessel,CRDM l' ' Ig. ~* I~J AI
(EAccelerometers) *Accelerometer (X,Y) AStrain gauge (Fuel rod)EAccelerometer (Z) A Strain gauge (Control rod
guide thimble)(J ® 9 Show fuel assembly type classified
by sensor positionsUpper test Arranged with strain gauge on the upper
vessel ~~~~~~~~~~~~~and lower ends of outermost fuel rods and
thimble tubesArranged with strain gauge on three grid-
Miese t level to study vertical strain distributionForce__ _ 11 _ _ Force
Lower test
Displaceme Displcemenmeasuring Im][ ~ ] ~ L t ii_~fi~=ieasuring
sensor ~ ~ ~ ~ ~ ~ ~ ~ ~~__sensorFiberscope (No. 5 grid position)
Vibration table___ _ _
Proving test model -…Displacement
(R~~~~ccelerometers) ~~~~~- - __measuring
(E~~~~ccelerometers) se~~~~~~~~~~~~~~~~~nsorDisplacement -- _ --- _
measuring sensor - -- -- - - : = - pru.ForceIsgauge
Force- -… ……-
gauge- - -- - -
Vibatin tble__
Design confirmation model_= = = i i
Fig.3.1-1O Seismic proving test model of reactor internals(15x3 arrangement of fuel assembly full scale)
3.1-15
Force gauge Fregauge
Displacement Displacementmeasuring measuringsensor Fiberscope (No. 5 grid position) sensor
___ ___ 1 ~~~~~~~~~~~~~ 1 ~ ~ Frc gauge____ ____ ____ - -il-i j~~~~~~~~~~JI JI ~~Displacement
Force gauge measuringDisplacement __ Displacement Foc ag J J sensormeasuring -- measuring i<~sensor __ __ __ __sensor DiAaee~L__ __1-measuriemngtI Ce nter row is same-I ias the row model
sensor L __ __ __ __ __
Force gauge _ _ Force gauge ~I Z_ _ _ ~~~~~~~~~Force gauge -gi
_ _ _ _ _ _ _ ~~~~~~~~~~~~Displacmn_[ [ ~ 2measuring_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ s e n s o r
Fig. 3.1-11 7x1 arrangement model (full scale) Fig.3.1-12 7x7 arrengement model (full scale)
3.1-16
3.2 Reactor InternalsThe structure of reactor internals is rigid, and since it is a large-sized and heavy weight
structure, it is difficult to carry out the seismic experimental test of actual plant size.Moreover, it is the fequency to which actual plant size also exceeds 20Hz.
Since frequency becomes high and exceeds the shaking table ability range in the experimentaltest that used the scale model, the experimental test by the scale model is also difficult.Therefore, in order to check the validity of an analysis model, the experimental test which
checks individually the rigidity of the structure that is carrying out complicated form, and the
vibration character'istic experimental test of the assembly using the flow vibration test, etc. are
performed.For the prototype plant of a newly designed PR, a system vibration measurement
experimental test is performed using a full-scale model, the vibration characteristic of a
structure is measured, and the validity of an analysis model is checked.Here, the test models design for the reactor internals those are shown in Fig. 3.2-1 are
explained.Stiffness and vibration characteristic test for the complicated structureScale model vibration characteristic experimental test
Seismic Proving test of a component
3.2 -1
Low impedance Mechanical test Component test
Rigidity of RCC guide tube
Frequency of RCC guide tube (in air!1 water)
Vibration Characteristics Scale model flow vibration test
Code verification
Tapping In water
Actuator In air water
\JJZ ~~~~Flow vibration test In water
Approval & Seismic proving test (NUPEC)Acceptance
Integrity of reactor internals and fuel
RCC drop test
Fig 3.2-1 Seismic tests for reactor internals
3.2-2
a. Mechanical characteristics testAs for the reactor internals, since the complicated shape of structure and support condition as acontrol rod cluster guide tube consist of a support pin, the experimental test which checik stiffnessand an vibration characteristics is performed.Stiffness and a vibration characteristic experimental test are performed to confirm fixed condition,
and an experimental test result is used as input conditions of a vibration analysis model.An experimental test is carried out in air and underwater conditions, which is shown in Fig. 3.2-2.Especially, the underwater basic frequency of a RCC guide tube is grasped, and the influence ofunderwater addition mass is checked.
- ~The frequency in system condition is possible by analysis considering the influence of
temperature to physical-properties value by analysis.H-owever, it is supplemented with a check on system operation conditions by flow vibrationmeasurement of the system.
3.2-3
Rigfidity test(l12)
*Purpose:Verification of the FEM analysis model
*Test load condition: Design Flow Load
Mock up~~~~~~~~~~~~~~~~~~~~~~~.
0SupportHydraulic
Sppor actuatorStn
Fig 3.2-2 RCC guide tube Rigidity test model3.2-4
b. Scale Model Flow Vibration Test.In order to verify the vibration characteristics of the reactor internals, the flow test carried out byusing the scale model. This result is used to confirm validity of a seismic analysis model.This flow vibration test does is restricted by the similarity of the system and the capability of theflow rate of the pump for test equipment.
Although to consider as big scale as possible is desired in vibration measurement in order tomake small influence of measurement sensor size. The model of this flow test is modeled
according to the similarity rule of the scale model that can do Fig. 3.2-3 and 4 system structures.H-owever, since modeling to which the fuel assembly followed the similarity rule is difficult.Using orifice device, but vibration characteristics of fuel assembly was not simulated, simulatesthe flow resistance of a reactor core.Vibration characteristics of the reactor internals is measured in air and under water conditions.
3.2- 5
Core Barrel
Air Spring
ActuatorSupport
, ,~~~~77--
Fig 3.2-3 Reactor internals test model for
flow induced vibration test3.2 -6
c. Seismic proving testThe structure of reactor internals is rigid, and since it is a large-sized and heavy weight structure,it is difficult to carry out an seismic experimental test of system size among a maker or electricpower company.H-owever, in order to check the function of the soundness of a actual plant reactor core, and thecontrol rod insertion function under an earthquake condition, the experimental test which used theexperimental test model of the full scale figure 3.2-5 was carried out by NTJPEC in 1986.A reactor core is shown in Fig. 3.2-6. The reactor core of 4-loop size in which the full scale fuelassembly of the 15 rows and three lines are settled.
-It was carried out by modeling that that is right and the lower reactor core plate which supports afuel assembly, and an upper reactor core structure- Response seismic wave of the structure of reactor internals was gave by shaking table- Even the lower reactor core plate was modeled, and the lower mirror was omitted to short height.- The upper reactor core structure modeled the upper reactor core support plate, the upper coreplate, and the upper support columns to the partial model.
And the apparatus of structure required for fuel assemblies support and guide components of acontrol rod driveline was simulated. In this experimental test, the vibration displacement of thefuel assembly in an actual core, the driveline apparatus of two sequences of the reactor corecentral part and a perimeter part was modeled.
3.2-7
oc
alibi
PW R X't, of V, c, W3.Z 13
QO
Horizontal vibration
Proving test model900 270' (15 X 3)
Control rod drivemechanism (CRDM)seismic support 10
CRDM 35 T
_____ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ -* ~~Horizontal vibration(00 )
Upper test vessel Design confirmation modelC> ~~90, 2700
Upper core support plate -(Sqaro4l(TX7
C) RCC guide tube___
Middle test vesselUpper core pteI
Core barrelO
Fuel assembly Horizontal vibration
Lower test vessel
Radial support ~~~~~~~~~90 270, Design confirmation modelRadoile cuport i liii~~i~~l Row model(7 X 1)
support plate $0 394
p84~~~~~~~~~~~~~10Virtion table
Sectional plan of core region (C-C)
Fig. 3.2-5 Reactor internals model for seismic proving test3.2 9
3.3 CRDM and Integrated Head Package seismic testThe pressure housing of CRDM is long cylinder form, and is the structure that can bemodeled with simple mass and a simple beam as a vibration model. H-owever, the strulcturegap of a seismic support part is existing to avoid interference, the experimental test which thecontrol rod position indicator equipment which does not restrain heat modificationcomplicates the vibration characteristic, and checks the vibration characteristic at the time ofan earthquake is required.Moreover, there are the features, like the length to which a drive axis exists in CRDM withthe position of a control rod indicator. To the site where the earthquake conditions in Japanare severe,- not only upper seismic support, but middle seismic support is installed.Moreover, since the function of CRDM seismic support is given the nuclear reactor vesselunification structure part for CRDM support, the air cooling duct, etc.For time shortening at the time of a periodic inspection, and the amount reduction ofcontamination,5 it is necessary to check the influence of coupling vibration of CRDM andseismic support. There are three kinds of experimental tests as shown in Fig 3.3-1.- CRDM Vibration Characteristics Test- Vibration characteristics test with combined the CRDM and HP models- Seismic proving test (integrity and the control rod drop test)
3.3 -i
Low impedance Mcaical testCRMsnlmol
Full scale model
Freauencv. mode shaoe
-Damping
Wire-cutting method on site test
Code verification Vibration characteristics Couipling vibration of CRDM-IHP
Validity of beam analysis model
Coping vibration of CRD1M-IHP
Approval & Proving test Integrity of CRDM-IHPAcceptance
Verify the integrity
Verify the RCC scram function
FIG 3.3-1 Seismic test flow for the CRD)M-IH-P3.3 -2
a. CRDM Vibration Characteristics TestAs a vibration characteristic of CRDM, there is a test, which check frequency and attenuationconstant. Since CRDM is installed on the nuclear reactor head, the length of an adapter differs,and drive mechanism length and the length of drive axis housing are the same structures.Therefore, frequency changes somewhat with length of an adapter.Moreover, although a drive coil, a control rod position indicator coil, and seismic support aresupported by CRDM pressure housing, since the structure gap which prevents a cooling functionor interference by the heat expansion difference exists, an attenuation constant is high structure.Therefore, it is necessary to also simulate such structures to check an vibration characteristic. Inaddition, it is necessary to check whether frequency is influenced with the position of a drive axis.In order to check basic frequency, CRDM vibration test is performed using full size CRDM of one,as shown in Fig. 3.3-2.A drive coil, a coil of control rod position indicator, use the coil of full size. The experimental test,which cheeks the influence of the gap of a support part can be performed, by the experimental testwhich made the gap of a support part the parameter. However, the experimental test withconsideration to the interference between CRDMs needs to imitate two or more CRDMs. Since itis not efficient that this kind of experimental test uses much system equivalent CRDM as a modelinvestigates likeness influence of a scale model simplified in the vibration experimental test andanalysis of the system. There is a method of test in the actual plant and the method of Fig. 3.3-3.
3.3 -3
Support Spring
Rod Travel Housing
Apply Pre-displacement
-CRDM
Reactor Vssel headTest VesselI A
~\1 Y1 Y/1 <> /,AUpper Core Support Plate
Dash pot
Fig 3.3-2 Control rod drop test model3.3-4
CRDM Cooling shuroud
.. v. ~ ~ ~ ~ ~ ~ ~ CD
Reactor Vessel
Fig 3.3-3 Full scale vibration test of CRDM by wire cutting3.3-5
b. Vibration Characteristics Test for CRDM &IHP
In the system plant, 30 - 60 CRDMs are installed. Moreover, since the shelled structure ofCRDM seismic support integrated with the reactor vessel head becomes large-sized, it is difficultto model this in system size. Then, the experimental test which check coupled-vibration ofCRD3M and 1H-P was performed in the scale model shown in Fig. 3.3-4.- Since CRDM modeled a difference of length, three kinds of models were used.- The model was designed reflecting the result of a single vibration test.- CRDM frequency was stretched so that the frequency of the system might be simulated
according to the similarity rule of modeling of HP, although it is a scale model, and it wasadjusted by rigidity.
- 1H-P is about 30Hz in the system. At the scale model, since frequency exceeds 50H4z of theactuating performance of an shaking table, the increase in frequency is suppressed by using aplastic material smaller than the elastic modulus coefficient of IHP system material.
- The seismic support tie rod stiffness which supports 1H-P top end aimed at reduction of a verticalelastic coefficient ratio in consideration of using the plastic for HP material.
3.3- 6
Seismic Support Spring
-~~~ r ~~~ U Upper Seism~ic Support
Support Structure ii
~~fliK'~ ~~ IntegratedHead Package
__19T
Intermediate
Rod Travel Housing SesiSpor
Surnilated CRD)M
Al- ___ J:-
~'Shacker Table
Fig 3.3-4 Scale model for the CRDM-III seismic test3.3-7
c. Seismic proving test (integrity and the control rod drop test)Although CRDM usually holds the control rod in the steady state where it withdrawal from thereactor core, a control rod and guidance structure be healthy in case of an earthquake. The powersupply of CRDM is intercepted by the earthquake trip signal in case of an earthquake, and it isnecessary to release a drive axis, to drop a control rod, and to carry out the scram of the nuclearreactor.
In case of a control rod fall into the core, the effective drag force under an earthquake condition,the displacements of the fuel assembly and CRDM are dominant. In RCC drop test under seismiccondition, these displacemrents are given, an insertion experimental test is performed and the
- ~insertion function is checked as shown in Fig. 3.3-5.There are a control rod cluster guide tube, and guidance structure of a fuel assembly, andmodeling of a control rod cluster required. Any model is using the model of a system equivalentarticle.- An experimental test performs the next experimental test and measures the resistance at the timeof fall, and insertion time.
- Check the fall resistance depending on the displacement and acceleration in case of the drag byinterference in case a control rod fall drag experimental test control rod falls, flow resistance, and
an earthquake etc., and consider as input verification of analysis.
3.3 -8
- Full scale CRDM for a test model is used.- The displacement of driveline equipment is given statically or dynamically.- Measure fall time, and a control rod fall test fall experimental test estimates a difference with
the case where displacement is not given,- Check the validity of resistance of fall analysis by it.- In case of the single channel test model, the experimental test method of actuating with two or
more actuator machines was used. In the structure seismic proving experimental test of the
reactor internals of NUPEC, the fuel assembly of the maximum arrangement of a system reactorcore and the driveline of two channels were modeled.
3.3-9
Small Gap Upper Seismic- Support
Actuator 3
RPI
CRDM ~Intermediateearthquake Actuator ~~~~~~~~Seismic Support
-- CRMearthquake Actuatorr___ wave
Vessel~~~~~~~~~~Vse
FiCR-D RCdoMts oe ocp
3.3-10 ~ ctatr
4 ScalingBy the seismic proving test, it recommends using the model of full size as follows to IAEAPara.512 strongly recomm-ended for scaling.
512. Seismic tests may be performed on the item itself or on a full scale model or, where appropriate, on reduced
scale models. However, for qualification purposes, it is strongly recommended that the component itself or a full
scale model without any simplification should be tested; if there is no other practical alternative, the careful use of a
reduced scale model may be permitted for qualification purposes. Such tests include:
* functional tests intended to ensure the required safety function of the component orabsence of transient malfunctioning during and after an earthquake
. integrity tests aimed at proving the mechanical strength of the componentThe view of scaling explains the design of the test model which uses a scale model. Restrictionconditions when using a scale model are shown below.-The manufacture accuracy of each part suitable for the experimental purpose is securable.-Test models including support structure should ride on an shaking table.-The excellence peculiar frequency of a model should not exceed the capability limit of an shaking
table.-The frequency of a support part is high enough as compared with the frequency of an test model.
4-1
5 Modeling design of Seismic TestReactor internals structure has high natural frequency. The frequency of the actual size of thereactor internals is close to the functional maximum of a shaking table. When the model of Fullscale is used, sufficient shaking test is impossible from restriction of a shaking table performance.Therefore, a scale model is used for a while. When using a scale model, a similarity rule fromwhich the frequency of a model turns into frequency within the performance range of a shakingtable is chosen. The design to which the number of system vibration lowers frequency when highcompared with a shaking table is performed. On the contrary, in the case of the frequency of the
2 models that becomes the minimum side of the actuation capability of shaking table, it designs sothat the frequency of a model may become higher than the actual size. Here, it is shown twoexamples of an examination objective of design, and the details of a model design also includingscaling are explained.
- Seismic Test Model design of a CRDM-IHP- Seismic Test Model design of a Reactor Internals
5.1 Seismic Test Model design of a CRDM-IHPAlthough Chapter 4 explained the similarity rule of a model, a test model structure design is shownhere. The HP seismic test introduced here has quoted the research result which three companies ofelectric power in Japan and Mitsubishi contributed in cooperation.IHP system structure is shown in Fig. 5.1-1. The whole reactor core, and a hemisphere type nuclearreactor vessel head arrange about more than 60 CRD)Ms, adapter length differs, and frequencydiffers somewhat.1HP structure is the cylinder structure that encloses the arrangement of CRDM. And it is thestructure that is integrated seismic supports structure, a CRDM cooling duct, and bolts tensioner atthe time of vessel head opening, etc. And with the tie rod, the upper end of HP is connected withthe anchor by the side of concrete, and is supported. Earthquake load is inputted from the tie rod ofan upper end a nuclear reactor vessel side.In advance of manufacture of an experimental test model, the dominant frequencies and vibrationmode of a test model structure are checked.As a result of calculating frequency in the FEM vibration analysis model that shows the HPstructure shown in 5.1-land Fig. 5.1-2, it is about 30Hz. When a scale model is used and materialis made the same as that of the system, the rate of a scale will exceed 50H-z of restriction ofexcellence frequency of a shaking table also one half.
5.1-2
Then, it considered as modeling which lowers frequency by using a plastic with a small elasticmodulus coefficient for material.Here, the 1/3.2 scale was chosen as a rate of a scale from which the beam mode frequency of an1HP seismic test model becomes equivalent to the system. Each parameter by the similarity rule ofa model is shown in Table 5.1-1.A model is made as follows, taking a similarity rule and the experiment purpose into considerationenough.
(1) HPFrom the purpose of the exam that grasps the vibration action of a complicated unificationstructure, main rigidity part material, such as main beam and seismic support, and a lower endjoint part simulate thing as much as possible. However, the small part material of rigidcontribution, such as a hoist rail and a cable tray, simulates only weight.
(2) CRDMThen, CRDM makes a model as follows paying attention to the influence that it has on aunification structure. CRDM from which natural frequency differs is in the group, and a groupdivision of group is transposed to 21 sets with natural frequency at one beam model. At this time,the mass of each beam model and frequencies are in agreement with the group (total mass, averagefrequency). However, it considers as steel on account of manufacture.
5.1 -3
(3) Reactor VesselSince it is a support boundary, only a unification structure and a junction part with CRD)M aresimulated.
(4) Tie RodThe integrated structure is being fixed to internal concrete through the tie rod. In order to simulatethis condition, the support implement that hits the spring part material that simulated the springconstant of a tie rod, and internal concrete is formed. A support implement is made into steel fromthe necessity of making the peculiar frequency sufficiently high.Therefore, this experimental test grasps the coupling vibration characteristic of CRDM-IHP in ascale model, and is performed by experimental positioning that checks the validity of a designanalysis model.That is, the experimental test model that modeled the structure of the system and the vibrationcharacteristic is manufactured,-and the vibration characteristic which calculated the experimentaltest result and test model of this model by FEM analysis model, and an vibration response arecompared. When the experimental test result and the analysis result were equivalent, the validity of an analysis model was checked. The vibrationcharacteristics of the system and response calculation need. to perform evaluation withconsideration to a operation environment of system.
5.1-4
Table 5. 1-1 The similarity rule of a model
(1) length (M ~ p/~rm-N(2) area (A)* Ap/Am-N'
(3) density (p*pP/ pm
(4) elasticity (E)* Ep/Em(5) strain (EEP/E M
(6) stress (aaP/ am~ Ep/Em(7) displacemnent(X) Xp/Xm
(8) force (P) Pp/Pm=Ep/EmixN
(9) weight (W) Wp/Wmi= p p/ p mxN3
(10) frequency() fp/fm~(Ep/Ern. p p/p rn)"12 . N-1(11) aeceraration(c) xp/khv --Ep/Ernx p rn/p pxN' (12) time (t) tp/tnm(Ep/Ern. p / p p)- 12. N
* ~Only the unification structure model made from a plastic is realized,,
* * To CRDM, it is as follows. a p/ a m= (Mp/Zp)/(Mm/Zmn)
Subscript p Actual Plant m s scale model
5.1-5
Frame Pin
Upper Seismic Tie-Rd A Te Ro
Support
A g~~~~ B~racket
Stiffener Intermediate Support
CRDM ~~~~~~~~~~Stud Bolt
Mlaine Frame
B Aii9
Fig 5.1-1 Integrated Head Packegefor Seismic support structure of CRD)M
5.1-6
- �
� -a
I,� �_ -r pr
11 ill/
"� �i pjj �:� I
'I-4
�\�2J�&yII � � � 1��-{j�� A
�: �
I- :�a-� � --
j�r � III JJ��
4
(First mode 30HZ)
Fig 5.1-2 3-dimensional FEM analysis model of IHP structure
5.1-7
CRDM Seismic SupportTie Rod
1HP Beam Mlodel
pin
Fig 5.1-3 2-dimensional beam model to simplify the IHP structure
5.1-8
Fig 5.1-4 Photo. of 11IP test niodel F-,ig 5. 1-5 Photo. of allover view
of a vib ration characteristiccs test of test mode on shakcer table
5.2 Seismic Test Model design of a Reactor InternalsAdvanced PWR adopts the neutron reflector constituted from a metal block by the reactor. coredomain, and adopts reflecting a neutron and gathering the combustion efficiency of the fel of acircumference part. And the structure abolishes a bolt from a high irradiation zone and raisingreliability while enlarging a reactor core and increasing an output sharply.Since it is the structure where a neutron reflector has a narrow gap as that is right, underwaterfrequency with the strong fluid induced effect falls greatly, and becomes low with about 6z.Although considered as 1 / 4 scale model used as 10-20Hz with the sufficient efficiency of theshaking table performance, the irregular similarity rule which doubles frequency for horizontaldirection by adjusting the rigidity of a support part is used. Consequently, it is satisfactory, even ifit level-reaches and carries out up-and-down motion simultaneous excitation, since the similarityrule of acceleration becomes 1.0 time,' and the dimension of a horizontal direction and the verticaldirection is the same. An test model examines scaling in consideration of the size of an shakingtable, and the maximum acceleration of loading actuating capability and a seismic wave.
5.2- 1
Design Features of APWR Reactor Internals
~~~~ ~~~Structure~~~~~~* ~~~~~~~~~~~~~~ -~~~~~~~~1
Baffle Radial9 able Former Reflector
0SubstitutionEnlargement
RNV .D.
4.4m 5.l m w
CONVENTIONAL 4 LOOP PWR APR
Comparison of RA Structure5.2- 2
Purpose of Seismic Test erification Items
* Verification of R/R Dynamic Behavior in the Earthquake
jDInvestigate Displacement Dependency of FSI Effec
Z9Investigate Influence of Non- linear Effects
Application XD&® to Analytical Model
5.2- 35
Scale ~~LI~ ),.~ MITSUBISHILarge o-4'ImegsfonaI ~~artn~tua~e ~,mu~a ror HEAVY INDUSTRIES, LTD).SIX111 tale TAKASAGO R&D CENTER
Excitation Force jLong Stroke Actuator(±300m 30tonX2) Z
X Direction: 1 20ton. gY Direction :60ton. gZ Direction: 200torn.g
Maximum Displacemen
X Direction* +50mm __
Y Direction: ±30mm iji~Z Direction: ±110mmZI1
10
~ .G
Table Size
6mX6mXl m
ctl~~~~~~~~~HrznalAtao
Maximum Loading HrznaAcutrVertical ActuatorWeight (±50m, 3Oton.4) (±1 1 0mm, 50tonX4)
1 Q0ton max_________________________ 0.01
0.1 ~ 1 10 100Freqiuency Rag0. Frequency (Hz)
Performance Diagram 524
0--50Hz (Loading Weight 30ton)
___Design Concept of Test Model
gjLength 114 Size Limitation of Shaking Table________(Scale-down) and Outer Water Tank
.Total Weight HNV Acceleration1164 28os251.34 G
Excitation Force < Limitation Force® Mass (=(1I4)~) 71/38 ton. G 120/200 ton.G
Performance Limitation of 3D Shaking Table»> Frequency Range ~2 Hz
1/2
(1 Tie ( Wavei Natural Frequency o R/R Test Model isPaeid Targeted at 12 Hz
Perid) » 6 Hz (Natural Frequency of Real-Scale_ _ _ _ _ _ _ _ _ _ _ _ _ _ _R IR ) x 2
5.2 -5 9
Acc.[LT2]=Length[L] x (Frequency[1lIT])
Gravity Acc. Control
Normal Similarity
Acc. ratio= 1/4 x (4)2=4I'cesr
Special Similarity
Acc. ratio= 1/4 x (2)= Unnecessary
5.2 -6
Test Model Rin Block
Design Concept-~EqivaentCross-section Area
Simplification
\ I ,~~ [Table Size Limitation
M2 /Ratio
O. D. 114
r~rfl~~ w hr~ Y h w~W eig ht 1/ 4_ _ _ _ _ _ _ _ _ _ _
Actual Test5.2 -7 12
Test Model*~~~*~~4~~r ,4~~~LOW
~~ ~Clearance AdjustmentBlock (4corners)
Upper BlockAlignment Pin
R/R (Ring block)
Ring BlockAlignment Pin - +
Pulling Device>Lift Force
Bottom Plate ......
Lower BlockAlignment Pin
5.2-89
Mock-u Photos
Detail BA1
5.2- 9
6. Location of Instruments and type of acquisition toolsTest measurement item and sensor arrangements are decided by the experimental purpose and a testobjective of the scale model. And the size and kind of sensor are chosen by a size, test environment,etc.. Here, test measurement is explained by making two kinds of examinations as follows into an
exercise..• PWR Reactor Internals Flow Induced vibration test.
• CRD)M - IHP Seismic Proving Test
The following sensors are attached in a vibration test of an seismic experimental test, a flowinduced vibration test,' etc.- Accelerometer.
- Displacement sensor- Strain gauge.
- Load sell.
- Pressure gauge.
6- 1
Proper use of each sensor is as follows.- measurement of frequency -
- an accelerometer, displacement meter are used. It can be found in the thing of each signal to do
for a spectrum analysis.- As for measurement of an damping constant, an accelerometer with high sensitivity is used.- Measurement in oscillating mode -
- An accelerometer and displacement -- the total is used Measurement installs the required numberwith the required number of the modes. - The measurement of structure intensity to vibrationexternal force uses a distortion meter.
- The load committed to a component uses a distortion meter. It asks for the relation between loadand distortion by the proofreading examination before the examination.
- Measurement of displacement -- contacted type and un-contacting type displacement -- thesystem adapting the total and the distortion meter is used - Measurement of pressure is used whenchanging fluid by vibration..
The kind of the measurement sensor and position of flow vibration test each experimental test of thestructure in 6.1 furnaces and sensor is illustrated.
6-2
6.1 Shell structureThe necessity of measuring the beam mode and the shell vibration mode is in vibrationmeasurement of a cylinder structure reactor core barrel, and arrange an accelerometer in thedirection of an axis, and the direction of a circumference. Refer to Fig. 6. 1- 1.The structure intensity by vibration and vibration;- The sensor arrangement which checks displacement is explained a sensor chooses fundamentally
the acceleration of the structure for measurement, displacement, and the position of distortionthat becomes large.
- Eight sensors are needed in order to measure to the forth mode of the core barrel as maindirection modes of a circumference.
- The center of the mode (n= 1) in which a lower end touches the direction of an axis in-~~~ consideration of the vibration mode, and object part material
- It can do (n= 2) -- in order to plan, three or more points are located- It is distorted among a flange part and installs the total in order to check structure soundness.- Vibration -- in order to measure displacement at the radial key part of reactor core barrel- Displacement -- In order to check a base motion, install a nuclear reactor container in a lid flange
and a lower end.
6- 3
6.2 Beam structureBeam mode vibration is a subject and beam part material, such as a beam part material controlrod cluster guide tube, an upper core support column, and an instrumentation guide pipe in areactor internals,
- Installs five accelerometers in vibration mode measurement from 3.- Moreover, in order to check the vibration direction, a sensor is arranged on two axes of X and Y
plane.- It is used for a strain gauge measuring the frequency and structure intensity.- Stress components of the membrane and bending, the direction of load,- It bends and a sensor is arranged in X and the direction of Y for separation of a components.- The example of arrangement of a sensor is shown in Fig. 6.1-2. 6.2
- Vertical simultaneous excitation shows a position in Fig. 6.1-3.- Although, as for this experimental test, four steps of ring blocks are being fixed with the tie rod,
at the time of an earthquake, it slides on a ring horizontally.- H-owever, since it is restrained by radial key, big displacement is not produced.- As a feature of a horizontal vibration, the influence of FSI is large and there are a thing
uinderwater frequency is greatly different in air, and a possibility that amplitude dependabilitywill arise.
6-4
- Moreover, in the case of the big earthquake of up-and-down motion, the phenomenon in
which a long block comes floating is also considered by axial force of a tie rod.- Then a motion of the level-upper and lower sides of a ring block and the relation between
frequency and external forces a radial key part, and a ring block come floating, and a sensorhas the necessity of measuring a fall action.
In this measurement, the sensor shown in Fig. 6.1-3 has been arranged.- Frequency and vibration mode: an accelerometer is installed at an shaking table, a container,
and a ring block- Arrangement the displacement gauge : to measure the relativity of Slide a base plate and a
ring- Load cell: atotal shock load at falling down the rings- Strain gauge: base plate- Installation Pressure: measure the relation of FSI and pressure change.
6- 5
6.3 An experimental test of CRDM-IHPIntegrated structure seismic test needs to measure the vibration mode (a beam, shell) of 11-IP, thebeam mode of CRDM, and structure intensity. Arrangement of a sensor shows Fig. 6.1-4 andmeasurement of CRDM for measurement of 1H-P in Fig. 6.1-5.The beam mode of the direction of a measurement axis of 1I-P and the response of a shell structurewere measured with the accelerometer. Frequency and the vibration mode were compared from anexperimental test and analysis.
From CRDM support function, the mode of a shell mode; seismic support part is important,and carried out important arrangement.CRDM: -- many CRDMs were modeled and the sensor used many strain gauges.The vibration response of CRDM has arranged the accelerometer into the largest portion.The kind of the measurement sensor position of each experimental test and sensor is illustrated.
6-6
Reactor Vessel
____ + ~~~~~~~~~~~~-270'
I ~ ~ ~ ~ ~ ~ ~~~'Y Vertical
RaelialDirection of Actuation
4~~~~91A i~~~~~~~ ~Displacement
Btom
Core Barrel
Core Barrel Therma-1Shild
hernial Shild ~~Middl Tp
Middle -
Direction of Actuation Mide
Bottom -
Botto Bottom
Fig. 6.1-1 Measuring points of core barrel for Flow Test
Accelerometer
(X )
Strain gauge ~ ~ ~ Stai gug
Str (o.,~~~~~Stai gaug
Accelerometer
Pressure ag
RCC Guide Tube ~Upper Support ColumnC-
Strain gauge
Instrumentation
Fig. 6.1-2 Measuring points of GT Support Columns
AJMeasurement Location22S'
Measurement Location* cD-(a®-*Displacernent
22 S'
O .~-Acceleromneter
5 y~ ~ ~ ~ ~ ~~~~~540 upraccelerometer4C)
-BMddle
111Strain gaugeBB
Actuation direction L3 5 4 50 -450
Fig. 6.1-3 Location of CRDM and IHP measurement
__________________________Sensor Evaluation Item s
Accelerometer* *~~~~'1Basic Vibration Responses
* ~~~~Displacement Vertical Opening andsensor Lifting Displacement
Aw;~ ~ ~ ~ ~ ~ ~ ~~~~ Horizontal Displacement
Load cell* *Impact Force
A ~~~~~~~~~~Strain gage -Tie-rod Tension, Lift Force,U Shear Load
77 ~~~~~~~~~~<Shaking Table> PressurePressure at Clearance for
transducer FSI Effect
Fig. 6.1-4 Measuring points of BMI
6- 10
Frequencycounter
Acceleration Cag
Strain Change Amplifier fite_ _ _ _ _ _ _ _ _ _ _B O X
-4i ~ Displacement Amplifier __________
Fig.6.1-5 Measurement block dagram
6-li
7. Conclusions• Types of a Seismic Test and pur pose are specified in AEA Seismic Guide• Number of mock-up for scale model of Seismic Test Model are shown.• The detailed of the test model is presented.• The test location of instruments and the Type of acquisition tools parameters are decided.
7 -1
Table 5.1 -1 The similarity rule of a model
(1) length (e) £p/emr= N(2) are a (A)* Ap/Am-N'(3) density (p*pP/ pm(4) elasticity (E)* Ep/Em(5) strain (E)E £P/E M(6) stress ()a Pa m -EpIEm(7) displacement(X) XpIXm.(8) force (P) Pp/Pm Ep/EmixN 2
(9) weight (W) Wp/Wm= p p/ p mxN'(10) frequency ( fp/fM -(Ep/EM. p/pmi) 112. N1(11) acceraration(x) kp/x-m =EpIEnx p M! p pxN-'(12) time (t) tp/tm(Ep/Em. p m/ p p) 12 . N
* ~Only the unification structure model made from a plastic is realized.* * ~To CRDM, it is as follows. a / CV m (Mp/Zp)/(Mm/Zm)
Subscript p Actual Plant m s scale model
