ML18044A379

Results from Charge Preamplifier Temp Test

ML18044A379
Person / Time
Site:	Palisades
Issue date:	11/30/1979
From:	Braul H, Cobb J, Lexa A BABCOCK & WILCOX CO.
To:
Shared Package
ML18044A372	List: ML18044A371 ML18044A373 ML18044A374 ML18044A376 ML18044A378 ML18044A379 ML18044A380 ML18044A381 ML19257A009
References
BAW-1590, NUDOCS 7912310513
Download: ML18044A379 (18)

Text

.. -

r-t I r

l

~

L r*

I.

I..

t

• 1 t

L.

r I l_

I L_

o;v1}. Cef]

.j ;<. ~-s-ATTACHMENT 7 RE SUL TS FROtfl CHARGE PREAMPLIFIER

• TEMPERATURE TEST

/

BA'N-1590 November 1979 I.I l 1/!7.a

• /

..f I.

Babcock & Wilcox 1912310 S-(J

RESULTS FROM CHARGE PREAMPLIFIER TEMPERATURE TEST by H-. J. Braul Special Products Operation BAW-1590 November 1979 Reviewed by 4 'r-\\ ~"\\_~'tl\\.~

J. M. Cobb Special Products Design Approved by: {ff. ~-'2YA A. F. Lexa,. anager Special Products Operation BABCOCK & WILCOX Power Generation Group Nuclear Power Generation Division P. O. Box 1260 Lynchburg, Virginia 24505 Babcock & Wilcox

"\\

CONTENTS

1.

INTRODUCTION * *. *

• 1.1. Background

• 1.2. Objective *

2.

INSTRUMENTATION *

• 2.1.

Introduction *

- 2.2. Calibration *

• 3.

PROCEDURE AND DATA ACQUISITION *

4.

CONCLUSIONS APPENDIXES A.- Test. Setup Equipment List :

B - Photographs of Test Setup

• List of Figures Figure

1.

477F Line Driver Temperature Test *******

2.

175 and 288F Line Driver Temperature Test ***

3. Test Setup, Block Diagram ************

4.

Chromel-Alumel Thennocouple Calibration Plot

- ii -

Page*

l 1

1 3

3 3

4 6

A-1 B-1 7

8 9

10 Babcock & Wilcox

,j

\\

1.

INTRODUCTION

• This report describes the test of the ability of the Unho1tz-Oickie Model 22CA-2TR remote charge preamplifier (li~e driver) to operate through high tem-peratures. The scope is limited to the work perfonned by the Operations Unit of the Special Products Section *. The requirements for the line drive tempera-ture test have been defined by the Special Products Design Unit.* Al1 data were recorded on magnetic tape. Throughout this report temperatures are ex-pressed iri degrees Fahrenheit {F).

1.1. Background From the Nuclear Regulatory Commission report entitled "TMI-2 Lessons Learned,

• Task for Status Report an~ Short-T~nn Reco1r111endat~ons" (NUREG-0578), came the requirement for*a valve monitoring system. Lirie drivers are an integral part of the valve monitoring system. These devices exhibit an extremely high input impedance (typically 10 to 100 Mn) and function first to convert the charge signal to a voltage signal, which can be amplified to a usable level. The Model 22CA-2TR is intended to operate with piezoelectric-type transducers; it receives power from the signal conditioning amplifier to which it is connected.

. In the valve monitoring system the 1 ine drivers. are within a few feet of the accelerometers and are thus exposed to high temperatures. This exposure to high temperatures caused concern for the line drivers' survivability.

1.2. Objective The tests were perfonned to verify the ability of line dri.vers, installed in* a Hoffman NEMA-4X stainless steel junction box, to operate after exposure to ~he following conditions:

• (l) J. M. Cobb to J. M. Brunke, Memorandum, "Line Driver Temperature Test, October 10, 1979; (2) J. M. Cobb to H. J. Braul and A. F. Lexa, Memorandum, 11Line Driver Temperature Test," October 10, 1979.

Babcock & Wilcox

1. Test No. 1 - Steam line break temperatures at 477F for 30 seconds and 175F for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, 47 minutes.

2. Test No. 2 - Small loss-of-coolant accident temperature at 288F for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Babcock & Wilcox

! (.

i..

l

'. i

' I t

i **

2.

INSTRUMENTATION In the first test only the line drivers were subjected to high temperatures; in the second, line drivers and one high-temperature accelerometer were tested.

Both tests were performed in a high-temperature (SOOF) bake-out oven.

2.1. Introduction A 1-kHz. 100-mV signal was used to check the line drivers before and after tests for signal degradation. During all the tests, an undistorted 100-mV rms, 1-kHz sine wave out of the function generator and a 1-V output from the line driver and signal conditioner, set at 10 g, were monitored. A periodic im-pacting on the oven was visible on the oscilloscope; this confirmed a good signal from the accelerometer.

For recording on-the tape recorder, track select and shuttle :features were used. This allowed for recording in the forward and reverse modes for 32 hours3.703704e-4 days <br />0.00889 hours <br />5.291005e-5 weeks <br />1.2176e-5 months <br />.

2.2. Calibration Each system component was individually calibrated at the NPGD shop before testing commenced.

The Honeywell 101 14-track tape recorder was set to record

. at 1.875 ips wideband. The chromel-alumel Type K thennocouple ~as calibrated to the thennoc~uple amplifier (see Figure 4}'.

The high... temperature acceler-

_ometer was shaken at an acceleration of l g nns, and the signal conditioner sensitivity*dial was adjusted to give an output voltage of l V rms.

Checking the thermocouple readings against the oven dial temperature readings, it was observed to be within +20 degrees.

Babcock & Wilcox i..

3.

PROCEDURE AND DAiA ACQUISITION A line driver was mounted in the junction box.

Feedthroughs into the junction box had rubber grommets for insulation.

~!icrodot softline cables were used*

for signal input and output of the line driver. These softline cables came from the line driver through the feedthrough of the junction box to the feed*

through of the oven.and connected to the appropriate electronics.

O~ this first test (477 and 175F) the temperature dial on the oven was set at 477F.

When the temperature reached this setting the door was opened and the junction box was inserted into the oven and the door closed quickly. About one minute before the temperature of 4i7F was obtained, the tape recorded was started.

After opening the*door, the oven temperature dropped to 320F; it took about 15 minutes to reach 4nF again. This peak was maintained for 30 seconds, then the dial was reset to 175F.

When the temperature dropped to 275F, the line driver faileq.

The total time this line driver was exposed to high temperatures is summarized:

Test No. 1 Retest

> 320F 15 minutes

~ 477F 30 seconds

> 275F 20 minutes The same procedure was followed with a new line driver except that the oven temperature was raised to 550F.

When the door was opened, the temperature dropped to about 480F, and the junction box was inserted. After 30 seconds'

- expos~re, the box was removed.

No line* driver failure occurred. At this point, the tape recorder was stopped and restarted to'record just before the 175F temperature was atta i.ned.

The di a 1 was reset to l 75F, and once the tem-perature stabilized, the box was inserted into the oven for 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />. The sig-nal was monitored, and no failure occurred.

Babcock & Wilcox I

i t.

Test No. 2 required 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />' exposure to 288F for two new line drivers (one in *each box) and one accelerometer.

Once the oven temperature stabilized at 288F, the same procedure was followed.

The test was started at 14:09 on oc~

tober 12, 1979, and completed the next day at 14~45. A power failure, which occurred at GS:OO, failed to activate the Deltec power supply for the tape recorder. The Deltec was supposed to supply power to the tape recorder in case of power failure. {Another Deltec power supply activated to maintain power to the oven.) Thus, recording stopped at OS:oo:

By checking at 14:00, after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in the oven, a signal was.still present on the oscilloscope.

Playing back the tape confirmed the presence of signals from 14:09 to 05:00.

From this it was concluded that the line driver did not fail.

Test No. l Retest October 15s 1979.

The same procedure was followed as for the first retest of Test No. l. No line driver failure occurred.

Babcock & Wilcox

4.

CONCLUSIONS

1.

One line driver failed when exposed to temperatures in excess of the re-quired values.

Reason: Exposure to high temperatures (320 to 477 and back to 275F) for too long-at 1 east 36 minutes.

Note: In reality for the 30-second temperature retest as

--.-- shown in Figure 1, the line driver was exposed to a temperature of 446 to 477F for at least 80 seconds.

2. During all the other tests, no line drive failures occurred.

3. The bias voltages on the signal conditioner were closely monitored; variations of 15 ta 60% occurred.

4.* All data are* traceable as to time and temperature.

5.

No deterioration of the gro11111ets~ the rubber seals on the junction boxes, or the softline cables was observed in visual inspection

• Babcock & Wilcox m

A>

D" n

0 n X"

RO

~

n 0

)(

r-- _..

I 10 20 F1gure 1.

477F Line Dr1ver Temperature Test II I 30 40 50 60 70 80 90 100 Time, seconds

500 400 ra.

300

~

~

QI ! 200 E-t 100 0

IJ 1 '* I I IJ I

. i\\'l 2

Figure 2.

175 and 288F Une Driver Temperature Test

~-

I l

+1.

I I

! I I I. p i

! I I. I

• I j I! ii' I i

I.

i I I',, I 1 I 111 !111 11 i,,

1, !

i !

111 111 I !

I il I I l! ! l I

... I 1*:T

'I I I 'I

. I a

• rime, h I

I.

I I

. I I

I' I

I I

11 I

'I II I I

~

I

~

11 ! I I

I I l

i,...,.;.

I !ti i

I

'~

I

~ I

• 11 I

-I -.

~....,

. I!

';

• l!

.n I

. I

.. t

• 1 L/D t

for ur*

I I

Figure 3. Test Setup, Block Diagram Bake-Out Oven ---

-1 Thermocouple I 0

I Accel e ometer I

Signal Line Driv~r 1 I

Conditioner I Sof tli Cable /

I Junction!

ne I

Bo.xes I

I I '

Pree a

~

Line

.. Driver 2 Capacitor i I I I I

Signal I

Conditioner I

I i:: J..I

.~B t~

~~

H Q) Q)

~'CJ 0

fiU i::.

~

I I Tape Recorder Oscilloscope

r..

\\

(.

\\

l..

Figure 4. Chromel-Alumel Thermocouple Calibration Plot

~ 300....: '.

=

1111

§!

=

100 so 60 40 20 0

100

%00 too Type K Thermocouple Clevite Amplifier Rar,ge: 40-50 Sens. Vernier: 0.00

. ~.

600 800 lODD Olltput lmV) --- v 1%00 Babcock & Wilcox

APPENOIX A iest Setup Equipment List A-1 Babcock & Wilcox

' t No. of units 2

1 5

1 1

1 1

1 1

1 1

1 2

2

2.

l Description Unholtz-Dickie Model P22MHA-l signal conditioner, Serial Nos.

1247 and 1255.

Endevco accelerometer, high-temperature, Serial No. AB-12.

Unholtz-Dickie remote charge preamplifier (line driver), Model 22CA-2TR, Serial Nos. 2408, 2856, 2433, 2391, and 2861.

Endevco 997 pf precision capacitor, Model 29478-1, Serial No.

PH24.

Tektroni'x function.generator, Model FG-504, Serisl No. 8042014.

Tektronix digital multi-meter, Model DM-501, Serial No. 81~1333.

Tektronix oscilloscope, Model SC-504, Serial No. 6011047.

Datum time code generator, Model 9300, Serial No. 1178.

Clevite thennocouple amplifier, Serial No. 249.

Chrome l ~a 1 ilme l type K thennocoup le.*

Honeywell 14-track tape recorder, Model 101, Serial No. 1300333EC79.

Applied Test System high-temperature furnace and control, Serial No. 2912.

Deltec uninterruptable power system, Models DSU 1810 and 1210, Serial Nos. 3387 and 3009.

Hoffman stainless steel junction boxes, Model A-8064 CHNFSS NEMA-4X.

Endevco microdot softline cable, No. *3090 (rating SOOF).

Unholtz-Dickie shaker table, Model 1602-6, Serial No. 1602-6.

A-2 Babcock & Wilcox

[.

APPENDIX B Photographs of Test Setup B-1 Babcock & Wilcox

OJ I

N Junction Box With Line Driver r-*---

Tape Recorder

.I

'- *****-*---**.,..-*... -*-*w,...;-...,..,.,_ - **~ ******.:t

I l_

Test Setup Test Setup With Bake-Out Oven B-3 Babcock & Wilcox