ML19249B681
| ML19249B681 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 08/14/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Eric Turner HOUSTON LIGHTING & POWER CO. |
| References | |
| NUDOCS 7909040664 | |
| Download: ML19249B681 (1) | |
Text
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UNITED STATES 8-NUCLEAR REGULATORY COMMISSION
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REGION IV o, 'tJf.M Gil HYAN PL AZA DHIVE, SUITE 1000 f
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August 14, 1979 In Reply Refar To:
RIV Docket Nos. 5 0 -93/IE Circular 30. 79-17 32 -99/IE Circular No. 79-17 Houston Qating & Power Company ATIN:
- h. E. A. Turner, Vice President Pcwer Plant Construction and Technical Services Post Office Box 1700 Houston, Texas 77001 Gentle =en:
This IE Circular is provided as an early notification of a possible significant matter.
It is expected that recipients will review the information for possible applicability to their facilities.
No specific action or response is requested at this time.
If further NRC cvaluations so indicate, an IE Bulletin will be issued to reconnend or request specific licensee actions.
If you have questions regardini, this matter, please contact the Director of the appropriate NRC Regional Office.
Sincerely,-
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V dar V.
eyfrit[
Director Enclosure.;:
1.
IE Circular No. 79-17 2.
List of IE Circulars Issued in the Last 6 Months o n,i' t U O u 's 7 909 0 4 0 b> @l
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Circular No. 79-17 Date:
August 14, 1979 Page 1 of I CO C ~ 3:'
r'1 IN 53-Z SWITCHES ON GENERAL ELECTRIC METALCLAD CIRCUIT B?l.J =
Th e C-- ~ ~ 2 Z1ectric Ccapany, Switchgear Department in Philadelphia, reported to tha 71 ' -- July 3, 1979, an intermittentccontact problem in SB-12 switches.
This -- '- "ttent contact problem will cause a lack of continuity through the "a" cen;;:n of the switch that is used to energize the trip coil of the circuit breaker.
Investigation disclosed that a die used to form a hole in the contact arms of the switch had worn, resulting in elongated holes.
This condition could pe rmit the contact bridge member to move laterally relative to the contact arm, occasionally resulting in improper "a" contact wipe.
The worn die has been corrected, and all switches shipped on or af ter July 1, 1979, include this correction.
A review of the history of these components indicates that switches shipped in the time period of August 1, 1978 to July 1, 1979, could have this p roblem. The trip coil and auxiliary switch portion of the trip circuit is monitored for continuity by a red light on the front door of the switchgear.
This light is lit when the breaker is closed and the control circuits are energized.
If the red light is lit, this indicates that the "a" contacts of the switch are closed, and that a trip signal will trip the breaker.
Based on the above, the licensees are advised to do the fol* lowing:
1.
Insure that all General Etectric Company Metalclad Circuit Breakers shipped to your facilities during the period from August 1, 1978 to July 1,1979 and used in or affecting the operation of safety related equipment are furnished with new SB-12 control switches as promptly as possible.
2.
Pending replacement of SB-12 control switches, administrative controls should be initiated to assure the red light which demonstrates contact continuity, is lit and remains lit each time these circuit breakers are closed.
No written response to this circular is required.
If you require additional informatioa regarding this subject, contact the Director of the appropriate NRC Regional Office.
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IE Circular No. 79-17 August 14, 1979 LISTING OF IE CIRCULARS ISSUED IN LAST SIX MONTHS Circ- --
Cubj ect Date of Issued To No.
Issue 79-03 Inadequate Guard 2/23/79 All Holders of and Training - Qualifica-applicants for Special tion and Falsified Nuclear Material Licenses Training Records in Safeguards Group I 79-04 Loose Locking Nut 3/16/79 All Holders of Reactor On Limitorque Valve Operating License (OL) or Operators Construction Permits (CP) 79-05 Moisture Leakage in 3/20/79 All Holders of Reactor Stranded Vire Conductors Operating License (OL) or Construction Permits (CP) 79-06 Failure to Use Syringe 4/19/79 All Holders of Medical and Battle Shields in Licensees except Teletherapy Nuclear Medicine Licensees 79-07 Unexpected Speed Increase 5/2/79 All Holders of BWR Operating of Reactor Recirculation Licenses (OLs) or Construc-MG Set Resulted in Reactor tion Permits (cps)
Power Increase 79-08 Attempted Extortion - Low 5/18/79 All Fuel Facilities and Enriched Uranium Reactors Licensed by NRC 79-09 Occurrer.2es of Split or 6/22/79 All Materials Priority I, Punctured Regulator Fuel Cycle and Operating Diaphragas in Certain Reactor Licenses (0L)
Self Contained Breathing Apparatus 79-10 Pipefittings Manufactured 6/26/79 nil Power Reactor Licensees from Unacceptable Material with a Constructi.on Permit and/or Operating License (OL) 79-11 Design / Construction 6/27/79 All Holders of and Applicants Interface Problem for Power Reactor Construction Permits (CP)
Enclocute Page 1 of 2 c311mo un t.:..'st_a
IE Circular No. 79-17 August 14, 1979 79-12 Potential Oi 3el Generator 6/28/79 All Power Reactor Licensee with Turbochar;er Problem a Construction Permit (CP) and/or Operating License (OL) 79-12 7.eplacetent af Diesel 7/13/79 All Power Reactor Licensee
~~ Fire Purg 3 2 ting with a Construction Peomit ontactors (CP) and/or Operating Licensee (OL) 79-14 Unauthorized Procurement 7/13/79 All Medical Licensees and Distribution of Except Teletheraphy XE-133 Medical Licensees and to all Radiopharmaceutical Suppliers 79-15 Bursting of High Pressure 8/8/79 All Materials Priority 1, Hose and Malfunction of Fuel Cycle and Operating Relief Valve "0" Ring in Power Reactor Licensees Certain Self-contained Breathing Apparatus 79-16 Excessive Radiation 8/16/79 All Radiography Exposures to Members Licensees of the General Public and a Radiographer Enclosure Page 2 of 2 b$>
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