ML17054D022
| ML17054D022 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/17/1976 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| Shared Package | |
| ML17054D021 | List: |
| References | |
| IEB-76-03, IEB-76-3, NUDOCS 7904200124 | |
| Download: ML17054D022 (12) | |
Text
Inspection and Enforcement Bulletin No. 76-03 "March 17, 1976 RELAY MALFUNCTIONS GE TYPE STD RELAYS DESCRIPTION OF CIRCUMSTANCES:
A malfunction of a General Electric (GE) Type 12STD15B5A Relay occurred recently in a safety related load center at Joseph M. Farley Station.
The relay malfunction was due to radio frequency interference from an activated transceiver.
This malfunction tripped the circuit breakers to isolate the associated transformer which resulted in the removal of the
,incoming power to the 600 volt load center.
Three other users of these devices have reported STD relay malfunctions due to radio frequency interference.
In addition, there have been several cases of failed shorted components on the STD relay amplifier card which resulted in relay malfunction.
The STD type relay may be installed in similar applications at BVR or PHR facilities.
The relays involved were in-itially marketed in 1968.
Portions of a GE service letter containing information about these relays are attached to this bulletin.
Further instructions regarding repair procedures can be obtained from the GE Service Engineering Department, Philadelphia.
ACTION TO BE TAKEN BY LICENSEES AND PERMIT HOLDERS:
Licensees of power reactor facilities with an operating license or construction permit are to take the following actions:
If you have received the attached GE service letter, describe what action you have taken regarding the recommended action to update your existing STD relays identified in the enclosed GE letter.
2.
If you have not. received the. attached GE service letter, describe what action you plan to take if relays of the type and model de-scribed in the enclosed GE letter are in use or planned for use in safety related systems.
3.
For facilities with operating licenses, a report of the above descriptions and plans, including the date when the actions were or will be completed, should be submitted within 30 days after receipt of this bulletin.
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4.
For facilities with construction permits, a report of the above descriptions and plans, including the date when the actions were or will be completed, should be submitted within 60 days after receipt of this bulletin.
Reports should be submitted to the Director of the NRC Regional Office and a copy should be forwarded to the NRC Officeof Inspection and Enforcement, Division of Reactor Inspection Programs, Washington, D. C.
20555.
Approval of NRC requirements for reports concerning possible generic problems has been obtained under 44 U.S.C.
3152 from the U. S. General Accounting Office.
(GAO Approval B-180255(R0072),
expires 7/31/77)
ATTAC&fENT:
Extract from General Electric Service Letter:
STD RELAYS TRANSF019IER DIFFERENTIAL RELAY
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IE Bulletin Number 76-03 ATTACHMENT A EXTRACT FROM GENERAL ELECTRIC SERVICE LETTER STD RELAYS TRANSFORMER DIFFERENTIAL RELAY In line with our policy of keeping users informed of conditions which could possibly affect relay operation, the following information is provided on type STD transformer differential relays.
Three customers have reported that the zener diodes or the associated dropping resistors on the STD Sense Amplifier Carh have failed shorted.
The problem has been traced to two zener diodes whose cases have been physically touching, short circuiting one diode and overloading the circuit. There are several possible causes of such isolated failures including the possibility of mishandling during test.
Incorrect STD relay trip outputs are associated with such a failure in this circuit.
Tests have shown that, with these components
- touching, the STD relay is also vulnerable to misoperation on DC transients.
Because of these reported problems, it is suggested that the clearance between the two 1N3024 diode cases and other component lead clearances on the sense amplifier card be visually inspected during routine STD test or maintenance.
When the problem was initially reported, insulating tubing was added to the zener diode in our manufacturing process as a future safeguard to prevent possible short circuiting due to deformation of the zener diode leads.
Subsequently, to further improve the STD relay, the sense ampli-
,fier card has been redesigned using a new printed circuit card with components arranged to preclude any possibility of short circuiting.
At the same time the card had been redesigned to improve the card layout, the STD dropout time was reduced to 32 milliseconds and its radio frequency sensitivity was reduced significantly.
- Thus, an updated relay will pass the RPI and Past Transient tests, and, of course, the standard IREE Surge Withstand Capability test.
In addition, a change in nameplate design makes the output contacts more visible.*
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r The new sense amplifier card is identified as 80108B9305 G-4. This new card will become a standard feature in all STD relays shipped after December 1,
1975.
At that time the STD model numbers will be changed in accordance with the attached list to reflect these
- changes, and the new relay models will be automatically substituted on unfilled orders.
Existing STD relays now in service can be updated with a new amplifier card, associated dropping resistors and minor wiring changes.
- None of these -design improvements affect the basic operating prin-ciples of the STD (operate on fundamental, restrain on all harmonics) nor do they change the restraint level from 20% harmonics.
These prin-ciples have been proven effective on over 35,000 G.E. harmonic restraint transformer differential relays, including those applied to transformers with the new high permeability core steel.
A reduction in the level of harmonic restraint is not desirable, as it would degrade performance (desensitize the relay in detecting faults during energizing) with no offsetting benefit.
OLD MODEL NUMBER NEW MODEL NUMBER KIT NUMBER 12STD15B1A 12STD15B2A 12STD15B3A 12STD15B4A 12STD15B5A 12STD15B6A 12STD16B1A 12STD16B2A 12STD16B3A 12STD16B4A 12STD16B5A 12STD16B6A 12STD16B7A 12STD17B1A 12STD17B2A 12STD18B1A 12STD18B2A 12STD18B3A 12STD18B4A 12STD21B1A 12STD15C3A 12STD15C2A 12STD15C3A 12STD15C4A 12STD15C5A 12STD15C6A 12STD16C3A 12STD16C4A 12STD16C3A 12STD16C4A 12STD16C5A 12STD16C6A 12STD16C7A 12STD17C2A'2STD17C2A 12STD18C2A 12STD18C2A 12STD18C3A 12STD18C4A 12STD21C1A 0152C9069 Gl 0152C9069 G2 0152C9069'3 0152C9069 G4 0152C9069 G5 0152C9069 G6 0152C9069 G7 0152C9069 G8 0152C9069 G9 0152C9069 G10 0152C9069 G11 0152C9069 G12 0152C9069 G13 0152C9069 G14 0152C9069 G15 0152C9069 G16 0152C9069 G17 0152C9069 G18 0152C9069 G19 0152C9069 G20
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OLD MODEL NUMBER 12STD25BlA 12STD25B2A 12STD25C1A 12STD25C2A 12STD26B1A 12STD28B1D 12STD28B2D NEW MODEL NUMBER 12STD25D2A 12STD25D2A 12STD25E2A 12STD25E2A 12STD26clA 12STD28C1D 12STD28C2D KIT NUMBER 0152C9069 G21 0152C9069 G22 0152C9069 G23 0152C9069 G24 0152C9069 G25 0152C9069 G26 0152C9069 G27 12STD29B1D 12STD29B2D 12STD29C1D 12STD29C2D 0152C9069 G28 0152C9069 G29
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UNIT LD STATCS NUCLEAR REGULATORY COMMISSION IIEGIOM I 031 PARK AVENUE KING OF PRUSSIA, PCNNSYI VANIA 10406 March 9, 19?6 Niagara Mohawk Power Corporation Attention:
Mr. R.
R. Schneidex Vice President Electric Operations 300 Erie Boulevard Vest
- Syracuse, New York 13202 Docket No. 50-220 Gentlemen:
Enclosed is XE Bulletin No. 76-01 which requires action by you with regard to your boiling water reactor facility with an operating license.
This issue of the bulletin, dated March 9, 1976 supercedes the previous issue dated March 5, 1976.
Should you have questions regarding this bulletin or the actions re-quixed of you, please contact this office.
Sincerely, James P. O'Reilly Dixector
Enclosure:
XE Bulletin No. ?6-01
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Approval of NRC requirements for xeports concerning possible generic problems has been obtained under 44 U.S.C.
3512 from the U.
S. General Accounting Office (GAO Approval B-180255 (R0072), expires 7/31/77).
cc:
T. E. Lempges, General Superintendent, Nuclear Generation T. J. Perkins, Station Superintendent C. L. Stuart, "Operations Supervisor E. B. Thomas,.Jr.,
Esquire A. Z. Roisman, Counsel for. Citizens Committee for Prot'.ection of the Envixonment bcc:
XH Files reactor Facilities Branch PDR Local PDR REG:X Reading Room HLD State of Ncw York u.p.c; gP Hayne /mjd 3/9/76 1+
Caflson 3/ '}/?6 Ioae3 ityYp r o $6x,fc h,os f;
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