ML20091Q841
| ML20091Q841 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 06/04/1984 |
| From: | Jens W DETROIT EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 126, EF2-68549, NUDOCS 8406140176 | |
| Download: ML20091Q841 (2) | |
Text
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Wayne H. Jens
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lea O tk<is Debolt Nb a IIce4 June 4, 1984 EF2-68549
' Mrl James ; G. Keppler
. Regional Administrator i
-Region III-U.
S. Nuclear Regulatory Commission 799-Roosevelt Road Glen ~Ellyn, Illinois 60137
Dear Mr. F:
eppler:
Reference:
~ -(l) Fermi 2 NRC Docket. No. 50-341.
(2) Letter, W.
H. Jens-t'o J.
G. Keppler, May 16, 1984, EF2-68536
Subject:
Interim. Report of: 10C FR50.' 55 ( e ) Item 126
" Underrated ~ Terminal Blocks in Limitorque Valve Operators" On May 4, 1984,; Detroit Edison's*Mr.
L.
P.
Bregni, Engineer -
-Licensing, telephoned Mr.
R.;C. Knop of the'NRC' Region III to:
4-
. report a potential-deficiency concerning-underrated motor
-terminal blocks manufactured'by Beau Products-installed in some Limitorque valve operators at-Fermi 2.-
Description of Deficiency Detroit E'dison first Jidentified ' the use of Beau Products
'No. 76000-series terminal blocks as a-result of an' inspection program.for;all'NUREG 058l Appendix E,. Category 2A and 2B Limitorque operators. 'There are eighty-eight (88) such operators ~withJthirteenJinside containment and seventy-five.
outside'~ containment.. This. inspection program was implemented:
asLtheicorrective' action;for a'previously reported deficien-cy,110CFR50.55'.e)' Item 125 " Environmentally 1 Unqualified Ter-~
-minalLBlocks'in Limitorque Valve Operatora".
This item was documented in-a final-report (Reference 2).on May 6, 1984.
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.Th'e Beau termina1Lblocks were found in'four SMC-04 Limitorque operators 41ocated'outside primary containmen,7 TheLterminal'
'blocksJwere being_used-.in 480V"AC motor ter4;g(ations, but according to the' Beau Products catalogue na've'an Underwriters
~
Laboratory.!(UL) rating of'150V-AC.
This lower rating is
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based-on creepage ' and : clearance distances for Class C L General Industrial terminal block applications as delineated in UL
' Standard 1059.
8406140176 840604
-PDR ADOCK 05000341 J. lf B
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Mr. James G. Keppler June 4, 1984 EF2-68549 Page.2-The manufacturer of the terminal blocks has oeen contacted and dielectric strength testing values have been identified based on the manufacturer's testing.
The tested dielectric strength is 10,500 volts rms between terminal points and is greater than 10,500 volts rms cetween terminal points and ground.. This information provides partial confidence that the terminal blocks will perform in their application.
However, dielectric testing values are influenced by such environmental conditions as temperature and humidity.
Analysis of Safety Implications The concern with these terminal blocks is the UL rating of 150 volts'rms vernus their application as motor terminal blocks which have a 480 volt potential phase to phase, add 277 volt potential phase to ground.
Both of these values are greater than the UL rating.
There is a potential for elec-trical shorting which could result in the failure of the
. motor to operate when required.
Failure of the motor to operate could compromise the function of the safety system of 5
which the valve is an integral part.
Corrective Action All Beau Products 76000 series terminal blocks found dur,in'g.-e the inspection of the eighty-eight Limitorque operators' dis '
cussed above will be replaced with environmentally qualified parts which meet.the proper electrical requirements.
To date, the inspection has been completed for the thirteenf-inside primary containment Limitorque operators and no Beau-Products terminal blocks were identified.
Thirty-two out of seventy-five Limitorque operators outside of primary containment have been inspected.
Of these, four were found to contain the Beau Products 76000 series terminal block.
The terminal blocks will also be evaluated for mild environment applications.
/
We1will provide another report on this item, either interim or final, when additional information is available.
If you have qu'estions concerning'this m'atter, please contact Mr. Lewis P. Dregni, (313) 586-5083.
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