ML20236Q187

From kanterella
Jump to navigation Jump to search
Elevated Temp Test Rept & Mechanical Pull Test Rept for Littelfuse Flas 5,5 AMP Fuses Lot 2,3,4 & 6
ML20236Q187
Person / Time
Site: Sequoyah  Tennessee Valley Authority icon.png
Issue date: 10/13/1987
From: William Jones, Ragsdale J, Wormsley J
TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20236Q176 List:
References
NUDOCS 8711190230
Download: ML20236Q187 (9)
v • d • e


Text

__

- f EIS 871013 001' 1

ELEVATED TEMPERATURE TEST REPORT AND MECHANICAL PULL TEST REPORT FOR j LITTELFUSE PLAS 5, 5 AMP FUSES l

LOT NOS. 002, 003, 004, and 006 l

l l

i l

l l

l pOS 1

" hisw d.

/.A[Wormaley,Engineef

. U, G. Qgnu

w. a. son.., ino n..,

dj a n d . . .

E p n.aas.eese,arg game -

Al M J

i. L. Noa7, p.r, ca.

8711190230 871117 7 ,

DR ADOCK 050

). t  ;

--- w mv weervaNugNEplwDg?SC3-C St5 697 4264 P.04 FORWARD ,

This intermediate report is being lesued at the request of the Division of Nuclear Engineering (DNE) for documentation 'of tests performed on Littelfuse fuses Lot Nos. 002, 003. 00a. and 006.

continuing.along with tests on later manufacturer'sTests on lots.

tot Nos. 00s and 006 are this report will also pertain to tests on these other lots. Several sections of PURPOSE Fuses rate at manuf actured Sequoyah by Littelfuse Nuclear plant. as Let 'No. 003 have exhibited a high failure These tests were conducted to determine . if.

the replacements manufactured as Lot No. 006 are of better quality, and if possible, to determine when the fuses in tot No. 006 will begin to fall. Lot No. 004 and future production lots may also be tested.

SCOPE Fuse samples were received from the plant for testing'in several conditions; used and still intact, used and f ailed, or as a test sample from a'new production lot.

Initial work consisted of preliminary examination of two failed fuses from Let No. 003, all other work was performed on fuses that. wore intact when received. Tests to destruction by r.iechanical loading, application of current for long periods of time, and elevated temperature were used to evaluate the fuses.

TECTS Scanning electron microscope photos of failed and intact fuses provided a preliminary method of failure and possibly some clue' as to how to test the remainder of the fuses. Sectioned samples were made to attempt to examine the internal porosity and bending of the~ soldered joint. Tests were set up to pass a nominal current of two amperes through approximately one half of the sample and four amperes through the other half. The time ~ until the first f ailure was asasured for each half of the sample. The current was reapplied to the sample, the time until the next f ailure recorded, and the resulting total number of days service for each sample lot wee reported weekly. Several of each lot were reserved for tests regarding mechanical load. bearing capabilities strength andand it" possible failure rate. to determine the relation between mechanical g y gest AVSu* .,

e 2 of 5 h (. ,

. . ., . m -e

'.s. cut.tOlhEERING tB?s;3-0 619 697 CB4 ' O.23 L.' ,

. \

TEST SPECIMEN IDENTIFICATION I

Specimens were identified by Lot No. and individual fuse according to the type test to be performed.  !

Fuses that were to be mechanically loaded to f ailure were designated " Lot No. 00K 5". The individual fuse number (example: Lot -

No.001, D.)

destruction. indicates the third fuse in Lot No. 6 that was pulled to The letter in the fuse which the individual fuse was subjected as described below. identifier refers to th

  • P" = pull tests "M" elevated temperature "L" = two Ampere current  !

"H" . four Ampere current PP00EDUPE 1 I

Scanning electron microscope photos of the fuses and mechanical tests of the strengths of the solder joints and the indicator pin actuating spring were used tests. to provide a preliminary cause of f ailure and to identify other needed Fuso holders arrangement forwere obtained long-term currentand tests.the fuses fitted into them in a series power supplies and loads were configured to obtain the nomine' test currents of' two and four' amperes.for }

sach test. A shunt of approxi. i in series with each group. A out aly the same resistance as a fuse was placed i monitored the current by sampling the voltage drop across theThe shunt.

data acquis lessor b'e low 0.8provided a printout every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, a printout if the current dropped amperes (indicating a blown fuse), a printout if the current went above 5 amperes (fuse current limit), and a printout on demand. In the event of a power failure the time will be printed in red until the correct time is resst. i These records show interruptions to the test and allow proper accumulation of the total test time.

REPORTS Daily reports preliminary t%sts.to the plant on an informal basis- were.made during the the plant. Weekly progress reports on long-term tests will be sent to Intermediate reports will be provided as report issued at the conclusion of the long-term current tests. requested and a final 3

TEST EDUIPMENT. y , a y

V .

Digital Thermometer, thermocouple, US TVA No.Flute 903320.Model 216SA, US TVA No. 462383, with type K Liquid in Glass Thermometer, US TVA 903322. * '

g sWC 3 of 5 g

\, f. *

{

, 10/13/1997 142 ;6 Ot2M/ ENGINEERING'DBPCO-O 613 E37 C64 P.06 Digita2 Volt Noter, fluke Model 8400A, US TVA No. 305678. i Data Acquisition System. US TVA No. 903250.  ;

Precision Resistors, US TVA No. 903309, US TVA No. 903310. US 7VA No. 90 US TVA 903312. US 77A 903319.

TEST DESCRIPTION Long No. 006 term on July current tests, as described in the procedure, were started for Lo* ,

August 11, 1987. 10, 1987, for Let No. 003 on July 21, 1987, and tot No. 004 or .

Scannin5 electron microscope photos and a meterials analysis of the selder in the fuse were reviewed by Ken Greene of DNE at the Central Laboratories Services Branch (CLSB).

These examinations and information provided by the manufacturer indicated that the element Bismuth was included in the used in Lot No. 003. Fuses from Lot No. 006 did not indicate a presence of Bismuth.

under no Fourelectrical fusesloadfrom each of Lot No. 003 and 006 were placed in an oven, at 200 degrees Parenheit on July 29, 1987 to  ;

point, was a cause of the failure of003Lot No. determine if the pres fuses.

l programmed to print the time when each fuse failed due to this temperature.The dat l

{

PESULTS The photographs taken at the CLSB indicated partial moltir.g was present in a of the failed porosity in the fuses; solder,however, there was also present a larse amount of by the solder inside thea great variability in the wettin$ of ths cemponents '

These fusos, and even one fuse with almost no solder.

! These problems also influenced to some extentproblems were v4wed The pull tests were made on tot No. the pull tests that were made.

' the solder joint was stronger than 002, 003, and 004 fuses and indicated that attached. the resistor body to which it was pounds lessThe thanLot Lot No.

No. 002 004 and 003 fuses pulled apart at approximately 10

1. The pull test results are attached as Appendix i

h covits of tne elevated temperature tests provided a more pronounced difference.

The first fuse from tot No. 003 failed within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The second failed priorand failed on September to 80 third hours fuses failed into the test.between 24 and 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> and the The first fuse _ from Lot No. 006' second fuse failed *on day AS, the third on day $1,oneand . .

fuse there re from Lot No. 006 that has not failed at present (71 days).

Additional tests on tot No. 00s, 006 and later manufactured. lots to measure the effects October 1, of temperature rise with various currents were reported to DNE 1987 (alms No. E13 871001 167 ), n o

results for Lot No. 003. but these results did not include

}

4 of 5 '

s

'A

. . . _ , . . ~ . - . - -

a m eruu4:En it& %P5C3-C EIS 697 4364 P.37 The Isng-tera curr;nt tests on Lot No.

The fuses in the higher. current loop 003 were discontinued af ter 40. days.

(which produced higher solder - joint temperatures in all Lot Nos.) f ailed at a much higher rate than Let Nos 004 and 006. Eleven of the fuses in the four ampere circuit f ailed within 33 days.

two ampere The first fuse in this circuit failed on day five of the test. In the days. circult only one fuse failed (at day 26) during a total of 40 than those No fuse in Lothas, at this time, failed in the long-term current tests other No. 003.

The duringphotographs, the tests are 'being data held logger records, and failed fuses that were not de at the current as appropriate. tests on all other fuse lots and will be included in the final r jaw:Oc5 01800 Best MadMC M i

1 1

l l

'l .,

b -

i j) 5 of 5

'y b ,

-3 _ _ ,

-)

APPENDIX I

]

FUSE IDENTIFIER SPRING TENSION PAILURE LOAD REMA RKS (1bs) (1bs)

LOT 002 P1 1.15 29.25 _ resistor body failed P2 1.12 5.25(pin) .

' spring unwound at 15.25 lbs P3 1.13 5.25(pin) spring unwound at 15.25 lbs

-)

i LOT 003 P1 1.23 5.25(pin) spring' unwound at 15.2$_Ibs P2 1.13 23.25 resistor body fallec.

P3 1.12 18.25 resistor body failed PA 1.14 22.25 resistor body failed PS 1.13 19.25 resistor body failed j P6 1.12 5.25(pin) spritig unwound at 11.25 lbs J P7 1.10 19.25 resistor body failed p8 1.12 22.25 reslutor-body failed i P9 1.15 22.25 resistor body failed  !

P10 1.13 24.25 resistor body failed-P11 1.18 i 5.25(pin) spring unwound at 13.25 lbs P12 1.13 F13 17.25 resistor body failed 1.13 10.25(pin) spring unwound at 11.25 lbs P14 1.03 5.25(pin) spring unvound at 11'.25 lbs P15 1.08 13.25(pin) spring unwound at 16.25 lbs P16 1.20 20.25 resistor body failed P17 1.20 {

5.25(pin) spring unwound at 13.25 lbs PIB 1.13 l 5.25(pin) spring unwound at 12.25 lbs l P19 1.09 13.25 resistor body failed P20 1.24 25.25 joint Iailed 1.

l l

LOT 004 P1 1.02 31.25 resistor body falled P2 1.06 I 29.25 resistor body failed '

P 3. 0.91 33.25 resistor body failed P4 0.80 34.25 spring-resistor joint failed P 5 .. 1.02 28.25 resistor body failed P6 1.07 35.25 resistor body failed P7 1.18 20.25(pin) spring unwound et 18.25 lba ^

P8 1.15 30.25 resistor body failed P9 ~

1.13 20.25(fatigue) weight applied overnight >

P10 1.15 P11 30.25 resistor body failed '

5 1.12 ~

33.2[ _ resistor body fa}1ed yayab\c CDW . :-

I. ( ,

I [ 32/;2/1997 14:49 C&EfVEN3]NEERING/DBS503-C 6:5 697 4:54 5.09

, APPENDU ((

est Available Copy FUSE IDENTIFIER STARI DAT8 STOP DATE TOTAL TIME Lot No.003 L1 7-21-87 6-31-87*

L2 7-21-87 40 days L3 6 31-87* 40 days 7-21-87 8-31-87*

LA 7-21-87 40 days LS 6-16-87 26 days  !

7-21-87 6-31-87*

i L6 7-21-87 40 days L7 6-31-875 40 days 7-21-87 6-31-875 LB 7-21-87 40 days L9 8-31-87* 40 days  !

7-71-87 6-31-87* i L10 7-21-87 40 days L12 .8-31-87* 40 days 7-21-87 6-31-87*

L12 7-21-87 40 days L13 8-31-875 40 days 7-21-87 6-31 87*

L14 7-21-87 40 days LIS 6-31 87* 40 days  !

7-21-87 6-31-87* i L16 7 21-87 40 days L17 6-31 87* 40 days

' 7-21-87 6-31-87*

L18 7-21-87 40 days L19 B-31-875 40 days 7-21-87 8-31-87*

L20 40. days 7-21,87 6-31-E7' 40 days FilSE IDENTIFI!_R START DATE STOP DATE TOTAL TIME kot No.003 H1 7-21-87 8-5-87 H2 7-21-87 15 days H3 7-30-87 9 days 7-21-87 8-31-875 H4 7-21-87 40 days  ;

HS 7-28-87 7 days '

7-21-87 7-28-87 N6 7-21-87 7 days '

. H7 6-31-87* 40 days 7-21-87 B-31-87*

HB 7-21-87 40 days H9 7-26-87 5 days 7-21-87 8-13-87 H10 7-21-87 23 days H11 6-31-875 40 days 7-21-87 8-31-875 E12 7-21-87 40 days HIS 8-11-87 21 days

_ 7-21-87 8-31-87*

H14 7-21-87 40 days 3 H1$ % 8-7-87 "17 days V 7-21-87 6-3$-87* ~

H16 7-21-87 40 days Hi? 8-6-87 16 days '

7-21-87 8-31-87*

H18 7-21-87 40 days H19 B-19-87 29 days 7-21-87 6-31-875 H2O 7-21-87 40 days 1 8-4-87 14 days

  • Lot No. 003 removed from test by instruction from DNE on 8-31-87.

'N

i Attachment 2 l 1

"Sequoyah Nuclear Plant j Littlefuse Type FLAS-05 Fuses Predicted Service Life SME-MET-87-901"  ;

i J

1 i

l i

1 f:

s*

e 1 1. ,

F .,,,,,,,....,,

~""~~~

- DNITt:D BTATES GOVERNMENT c4y B43 77 C 92 8 001-

]

Memorandum TENNESSEE VALLEY AUTHORITY To  :

I W. S. Raughley, Chief Electrical Engineer, W8 0126 C-K ynom  :

D. W. Wilsort, Chief Nuclear Engineer, W10 C126 C-K Hest Available Lopy utTE , ,SEP 281987 l st:10ECT:

SEQUOYAH LIFE NUCLEAR PLANT - LITTLETUSE TYPE FLAS-05 FUSES -

We are transmitting the Singleton Materials Engine.ering Laboratory report SHE-MET-87-901 as requested by Ken Green on August 18, 1987. Please refer i i

to a preliminary report on FLAS-05 fuses given as QIE NEB 87281 (B46 870919 003). I OU Und y D. W. Wilson (p,PVG:MHD p Attaohnents N.

oo (Attachments): \

...EINS._SL26 C-K t

s ,

W. H. Childres, SME-K j l

This was prepared principally by Paul V. Outhrie Jr., extension 2771. .

I i

l l

.]

4 A27149 7 . O t

1 .

_ _ - - _-___ -

Retrieved from "https://kanterella.com/w/index.php?title=ML20236Q187&oldid=3174826"