ML19351A027
| ML19351A027 | |
| Person / Time | |
|---|---|
| Site: | Humboldt Bay |
| Issue date: | 04/14/1981 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | AFFILIATION NOT ASSIGNED |
| Shared Package | |
| ML19351A020 | List: |
| References | |
| NUDOCS 8106250044 | |
| Download: ML19351A027 (1) | |
Text
aseoq#o UNITED STATES 8
NUCLEAR REGULATORY COMMISSION o
I REGION V o
g 1990 N. CALIFORNIA SOULEVARD g
SUITE 202. WALNUT CREEK PLAZA ag,,5 WALNUT CREEK, CALIFORNIA 94896 O
. April 14, 1981 i
Gentlemen:
The enclosed circular is forwarded for your information. No written response to this circular is required.
If you have any questions related to this matter, please contact this office.
Sincerely, R. H. Engelken Director
Enclosure:
j IE Circular No. 81-06 RI06250
SSINS No.: 6820 Accessession No.
8011040288 IEC 81-06 UNITED STATES-NUCLEAR REGULATORY COMMISSION 0FFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 April 14,1981 IE Circular 81-06: P0TENTIAL DEFICIENCY AFFECTING CERTAIN FOXBOR0 10 to F0 MILLIAMPERE TRANSMITTERS Description of Circumstances:
NRC has been recently advised of two deficiencies in certain E-10 Series Foxboro transmitters which could adversely affect their operation during accident conditions. The deficiencies involve the improper use of Teflon wire insulation and an unsuitable capacitor in the amplifier section of these transmitters.
The transmitters in question have been identified as Foxboro Models N-Ell, N-E13, anf E-11, E-13 with suffix Codes /MCA, /MCA/RRW, and /MCA/RR. These transmitters operate at at output signal level of 10 to 50 milliamperes (mA).
Similar model number units operating in the range of 4 to 20 mA are not a concern in these matters.
Briefly, the information on the deficiencies was brought to the attention of the NRC Staff during a recent meeting with several licensees of a " Utility Transmitter Qualification (UTQ) Group." This group has been formed to develop and implement an acceptable environmental qualification test program for safety-related electrical equipment in use or planned for use in nuclear power plants.
According to Foxboro, the Teflon insulation material in question has demonstrated I
a tendency to embrittle and deteriorate when subjected to /In integrated radiation dose of 200 megarads. A total integrated dose (TID) of 200 megarads was called for in the qualification test sponsored by the UTQ Group that led to the discovery of the Teflon insulation and capacitor problems.
With respect to the capacitor problem, the n.a ufacturer determined that the capacitor was not hermetically sealed as specified. Unsealed capacitors can leak and malfunction under adverse conditions, especially those of heat and time.
Foxboro determined that the capacitor failed after being subjected to high temperatures resulting from gamma heating during the above-mentioned qualification test.
4..~.u," un a *n-fA m discussed problems, Foxboro issued a f/_ng - --.
%*alllicensees,NSSSvendors, architect-
.-u the Foxboro 10 to 50 mA transmitters in f3 DUPLICATE DOCUMENT r describes the Teflon and capacitor
- j
- to identify and correct the problems.
Da Entire document previously
!r instruction (MI) booklet, MI-20-145, E
entered into system under:
- o 50 mA transmitters, to recipients of is been specifically marked on pages 5 ANO
\\\\O4/d M [
'ier in question.
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No. of pages:
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