Experi
In LOCA of EQ(Equ specified b NPPs(Nucle LOCA envi shorten this usually app IEEE Std.
degradation and aging t equivalent t Although s activation en effects are i most reason [2].
Although profile(one days), it ma pressure co equipment.
plays an imp the effects performance condition.
In this pa equipment different p switches.
Test spec and LS-T. T to another p 1. In perfo criteria of th Table 1 O Contact
point C N 1-2 3-4 5-6 7-8
O
mental Stu
1.
A(Loss Of Coo uipment Qu by accident ear Power P ironment is on s long test p ply aging ass
1205-2000 [ n of equipmen time and tem time and temp some limitat nergy of spec ncluded, the m nable solution h this metho
year) into s ay be justified ondition has n In case of e portant role in of pressure e will be as aper, we exam integrity dur pressure prof
2.
cimens are tw The limit swi point by movi ormance test, he limit switch
Operation prin Connecting stat
ormal Lever
O X X O X O O X O: connecting,
udy for Effe
Byu K
Introduction olant Acciden ualification),
environmenta Plants). Gene ne year in do profile, most sessment meth 1]. This met nt is a functio mperature can
perature by Ar tions such a cimen and disr method is gen for shortenin od convenien shortened pro d under the as no effects on equipment wh n its performa
condition on significant as mine the press
ring LOCA t files to two
Experiment wo limit switc itch transfers ing lever as p one exampl h is as follows nciple of limit tus
r on S
<norma , X: disconne
ects of Pres Sim
ung-ju Lim, C Korea Institute
bzo
n
nt) simulation test profile al conditions eral duration omestic NPPs test laborato hod presented thod defines on of temperat be changed rrhenius equat as constancy regard of pres nerally used as ng long test pe tly modify ofile(less than ssumption that n performance hich sealing ance maintena n the equipm s the tempera
ure effects on test by apply o identical l
ches named L electrical cur presented in T le of accepta s.
t switch
Schematic
al> <Lever o ecting
ssure Cond mulation T
Chang-dae Par e of Machinery [email protected]
n test e is
s of n of . To ories d in
that ture, into tion.
y of ssure
s the eriod long n 30
t the e of
part ance, ment ature n the ying limit
LS-R rrent Table ance
x x
x
E Fig prep day The test perf iden 2.1
R agin LO sho pre and the pro case exp 2.2
faci boil che sev
n>
dition on Eq Test
rk, Chi-sung S y and Materia re.kr
Insulation res ground: over Dielectric str ground: endu minute Electric con resistance les EQ test proce . 1. Prior to th pared in exac y, chamber, an e functional te t, and LOCA
formed in tw ntical tempera
LOCA Test co Required test ng assessmen
CA profiles o own in Fig. 3
ssure is accel d 252.0 kPa, re specimen LS file in Fig. 2 a e of temper posed to the sa Test Facilitie Figure 4 sh ility. It mainl ler, accumulat emical solution
eral control va
Fig. 1 EQ
quipment I
Song als
sistance betwe 10 MΩ apply rength betwee urance in app ntinuity of
s than 1 Ω dure for a lim he LOCA test ctly same agin nd tester until est is followed
A simulation wo different ature and chem
ondition profiles are nt method, w of one year to . The test pr lerated from espectively. In S-R is expose and LS-T to th rature profile ame test profil
s
hows schema ly consists of tor and superh n such as mix alves, and dat
Q test procedu
Integrity in
een each conta ying 500 Vdc en each conta lying 2,500 V
contact poin
mit switch is t, two limit sw ng conditions seismic quali d by seismic n tests are
pressure pro mical spray co
presented in we shortened o test profile ofile for temp 1001 second n case of press ed to the requ he test profile es, both spe le in Fig. 3.
atic diagram f steam gener
heater, sprayin xing tank and
ta acquisition
ure of limit sw
n LOCA
act point and act point and Vac during 1 nts: contact
presented in witches were such as test ification test.
qualification respectively ofiles under onditions.
n Fig. 2. By the required of 7 days as perature and at 128.0 oC sure profiles, uired LOCA e in Fig. 3. In
ecimens are
of the test rator such as
ng system of spray pump, system such
witch
Transactions of the Korean Nuclear Society Spring Meeting Gyeongju, Korea, May 29-30, 2008
615
100 101 102 103 104 105 106 107 125
150 175 200 225 250 275
300 Temperature
Pressure
Time [ Second ] Temperature [o F ]
0 10 20 30 40 50 60 70 80
start under 6.9 kPa and 48.9 oC
30 days 74.4 oC 121.1 oC
149.4 oC
365 days 64.1 kPa 227.5 kPa
Pressure [ psig ]
326.1 kPa
Fig. 2 Required LOCA profile
100 101 102 103 104 105 106
100 120 140 160 180 200 220 240 260 280 300 320 340
Temperature Pressure
Time [ Second ] Temperature [oF ]
Accelerating start, 1001 s
0 10 20 30 40 50 60 70 80
252.0 kPa 326.1 kPa
128.0 oC
Pressure [ psig ]
149.4 oC
Fig. 3 Test profile
Fig. 4 Schematics of LOCA test facility as PLC and LabVIEW software.
3. Results
The functional test is performed for two limit switches aged in different LOCA pressure condition.
The test results of the functional test before, during, and after the LOCA test are presented in Table 2.
Considering the acceptance criteria stated previously, the specimen LS-R maintained its integrity in performance and had no damages except for thermally aged stain. On the other hand, the specimen LS-T tested
in higher pressure condition did not need the requirement of acceptance criteria. For electric continuity test, contact resistances of contact points displayed in Table 1 have to maintain less than 1 ohm.
However, the resistances of the contact points were not satisfied with this criterion in functional test after the LOCA test. When disassembling the specimens, contact points of the specimen LS-T was intensely contaminated by steam and chemicals due to leakage of seal of limit switch case.
4. Conclusion
In LOCA simulation test of EQ, most test laboratories usually shorten test profile using aging assessment method which considers degradation related to temperature effect and regards that pressure condition has no effects on performance of a specimen. However, our test results in Table 2 show that higher test pressure may cause the critical failures in equipment performance after the LOCA simulation test. Therefore, pressure as well as temperature condition in LOCA simulation test should be considered as important factor in case of pressure-vulnerable equipment which sealing status has a critical effect on performance.
Table 2. Results of performance test for limit switches Performance Before test During test After test Insulation
resistance
LS-R 29.9 GΩ - 34.9 MΩ
LS-T 29.9 GΩ - -
Dielectric strength
LS-R Pass
LS-T Pass - -
Electric continuity,
[mΩ]
LS-R 60.9 57.8 64.2
LS-T Pass Pass Fail
REFERENCES
[1] IEEE Std 1205, “Assessing monitoring, and mitigating aging effects on Class 1E equipment used in nuclear power generating stations” (2000).
[2] C.D Park, B.J Lim, C.S Song, “Methodology for modification of LOCA environmental test profile”, NTHAS5, (2006).
Transactions of the Korean Nuclear Society Spring Meeting Gyeongju, Korea, May 29-30, 2008
616
