ML18219C413

08/26/1976 Letter Response to IE Bulletin 75-04A

ML18219C413
Person / Time
Site:	Cook
Issue date:	08/26/1976
From:	Hunter R American Electric Power Service Corp
To:	James Keppler NRC/IE, NRC/RGN-III
References
IEB-75-004A
Download: ML18219C413 (16)

Text

AMERICAN ELECTRIC POMfER iSQI'Vi CQ COI'POI'RLIOll 2 llroa<hoa~g, h'oui )'orf', F. K f0004 (2I2J i/22 -4800 IIOIII,"IIT S. IIUIfTFII Virr Prrsidrnt.Ãvclcar Enyirrrriny August 26, 1976 Donald C. Cook Nuclear Plant Docket No. 50-315 DPB No. g8 U.S. Nuclear Regulatory Commission.

Office of Inspection and Enforcement Region III 799 Roosevelt Road Glen Ellyn, Illinois 60137 Attention: M . . G. e e D ect Gentlemen:

Item 6 of IE Bulletin 75-04A requires a schedule for accomplishment of any revision to our policies and procedures and any proposed changes to the facility, to assure that con-sideration for alternate methods -for accomplishing an orderly plant shutdo>In and cooldown are provided in case of loss of normal and preferred alternate shutdovn and cooldorfn systems at the Donald C. Cook Nuclear Plant. Our letter to you dated t'une 27, 1975 provided this schedule.

In addition, Item 6 requests summary reports detailing our monthly progress. This letter is the fourteenth such monthly report.

The I ocal Shut'dovn Instrumentation panels for local monitoring of critical parameters in the event of an unlikely loss of control from the control room vere scheduled. to be shipped to the Cook Nuclear Plant site before the end of August. Hovever, after completing assembly of the panels, the fabricator's tests indicated an electrical fault in each of the panels. The fault vas subsequently found to be

'efective terminal blocks.

Spare terminal blocks vere available from stock at the Cook Nuclear Plant and the required type and number have been sent to the fabricator.

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P Mr. J. G. Kepplex ugust 26, 1976 Following refitting of the blocks and satisfactory completion of retesting, the panels will be-shipped to the site.

Delivery is expected in early. September.

Very truly yours, R. S. Hunter Vice President-Nuclear Engineering RSH:main cc: G.'Charnoff R. C. Callen P. N. Steketee R. Nalsh R. M. Jurgensen - Bridgman D.D. Comey John Tillinghast

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UNITED STATES NUCLEAR REGULATORY COMMISSION REGION III CENTRAL FILES 799 ROOSEVELT ROAD GLEN ELLYNs ILLINOIS 60137 AUG 17 ~o7"-

Am'er'iclec'tric'*Power'ervice Docket'o, 50-315 Co'r'p oration Docket No; 50-316 Indiana and M.chigan Power'ompany

,ATTN: 1fr; John E.- Dolan, Executive Vice Pr'esident Engineer'ing and Const'ruct'ion',

Br'oIadway Nei7'ork; Nevi York 10004

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Gentlemeri The3'e'nclosed Circular, 76-02'is forrmrded to you for information and action. This is the second'issue of an expanded system for communica-tion from the Office of Inspection and Enforcement to applicants and licensees,'to supplement the .issuance of IE Bulletins.

Il Bulletins have been, and will'ontinue to be, limited to sub)acts con-sidered to be of appropriate significance to require prompt response.

Circulars will cover sub5ects, of lesser significance, immediacy or for

, whicli a longer response time, appears appropriate. Puture IE Circulars may be iddressed to .any class of NRC licensees, and may or may not require response, IV Sincerely, James G. Keppler Regional Director

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Enclosure:

IE 'Circular 76-02 cc w/encl:

R. Q. Jurgensen, Plant Superintendent bcc'/encl: S

- 'Central Piles IE Piles PDR Local PDR Ronild Calleri, 14Kchigan Public Service Commission m 'avid "Dismore, Comey, Citizens for Better'Environment

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August 17, 1976 IE Circular No. 76-02 RELAY FAILURES-WESTINGHOUSE BF (ac) AND BFD (dc) RELAYS DESCRIPTION OF CIRCUMSTANCES:

During testing of Westinghouse BFD relays, the Point Beach nuclear power plant experienced malfunctions with two relays in the reactor trip system.

The malfunctions were caused by the pin that connects the plunger to the operating head rubbing against the contact block. Although the coils were fully energized the relay contacts remained in the deenergized position.

A similar malfunction occurred in one of a set of relays undergoing accelerated aging tests at the Westinghouse Beaver facility.

The malfunction relating to pin misalignment may be common to both BF (ac) and BFD (dc) relays. Portions of a Westinghouse service letter containing information about these relays are attached to this circular.

Further instructions regarding this relay problem can be obtained from Westinghouse Nuclear Service Division, Pittsburgh, Pennsylvania 15230.

ACTION TO BE TAKEN BY LICENSEES AND PERMIT HOLDERS:

The following actions should be taken with respect to all Westinghouse BF (ac) and BFD (dc) relays in safety related systems:

1. Describe the action taken or that you plan to take to verify that normally energized relays in safety related systems are in fact operable and that the relay contacts are in the energized position.

2. Describe the action taken or that you plan to take to verify that normally deenergized relays in safety related systems operate properly when energized and that the relay contacts are in the energized position.

Reports for facilities with operating licenses should be submitted within 60 days after receipt of this circular, and reports for facilities with construction permits should be submitted within 90 days after receipt of this circular. Your report should include the date when the above actions were or will be completed.

Reports should be submitted to the Director of the NRC Regional Office and a copy should be forwarded to the NRC Office of 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)

Attachment:

Extract from Westinghouse Service Letter:

BF (ac) and BFD (dc) Relays

EXTRACT FROM WESTINGHOUSE SERVICE LETTER:

BF & BFD RELAYS During the testing of certain Westinghouse BFD relays at an operating nuclear power plant, two relays in the reactor trip system were found to have malfunctions. Although the coils were fully energized, the relay contacts remained in the deenergized position. It was determined that, in both cases, the pin that connects the plunger to the operating head was rubbing against the contact block. This rubbing action resulted in friction that impeded the plunger movement when the relay coil was energized thereby preventing contact movement. The malfunctioning relays were immediately replaced. When dissassembled it was found that the relays would operate normally when the pin was centered in the plunger.

Coincidently, Westinghouse (Beaver) the relay manufacturer, experienced a similar malfunction in one of a set of similar relays which are currently ungergoing accelerated aging tests.

Westinghouse (Beaver) and Westinghouse (NES) are currently investigating this situation in detail as it applies to both BF (ac) and BFD (dc) models. Con-sideration is being given to various means by which the pin could be held cap-tive, thereby precluding further pin misalignment, if such. a course of action becomes necessary.

RECOMMENDED ACTION Visually inspect normally energized relays to verify that such relays are in fact picked up. Observe the performance of normally deenergized relays during normal periodic testing.

4 UNITED STATES CENTRIIL FI( ES NUCLEAR REGULATORY COMMISSION REGION III 799 ROOSEVELT ROAD GLEN ELI YN, ILLINOIS 60I37 July 28, 19?6 American El'ectric Power Sexvice Docket Ho; 50 315 Corporation ATTN: lfr;

Indisne end 1Kchigsa Power ColQpany Dolan, Executive Vice Pres'ident Engineerins end Constru'chion 2 Brosdway New York; Nev York 10004 Ciktl~)

The en'cia'sed Bulletin',- Ho; 76-07 is'o@iar'led to you fo'" information end iction'. 'A similar documiat -entitl'ed'Circulir'o. 76-01, is being trans'mitted to each holder of e"-Construction'Permit. Therefore, if'you have a'uclear power'pplsnt in the'on'structian'stoge, you will also receivecopy af Circulex;. No. 'N-'01 which'Q.X require s'eps'rate response'c'ou wQ1 noth'hat; th'e'significant difference be@a.ea'he two documents is the time II ella'or response, ead Enforcement Bulletins have beea and wi11 continue I'nspection to bi'l.imited to sub)'ects considered to'be af significance snd which require prompt. reiponse. 'Xa the-future, Bulletins will be supplemented- by Circulers es e coimunicatioa medium where the eub)ect matter is af lesser sisnificsacaq immediacy, or for which s longer response time ox no response may be acceptable.

Sincexely, James C. Keppler Regional Director Enclasure! bcc w/encl:

XE Bulletin No. '16-07 Central Files IE Files cc v/encl: PDR R. Q. Jurgensea, Plant Local PDR Sup eriatend eat Ronald Callen, Mic1d.san Public Service Commission p~TIOy R. J. Vollan, Businessmen for g4 the Public Interest OGC, Beth, P-506A O III ~

Reproduction Unit NRC 20b ff C

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July 28, 1976 IE Bulletin No. 76-07 CRANE HOIST CONTROL CIRCUIT MODIFICATIONS DESCRIPTION OP CIRCUMSTANCES:

In response to NRC concerns about the potential for, and consequences of, dropping a spent fuel shipping cask or other heavy load, Commonwealth Edison modified the 'hoist

'control system for the fuel cask handling cranes at their Dresden Units 2 and 3 and Quad-Cities Units 1 and 2 to provide additional hoist redundancy and slow speed hoist capability. The original design utilized a General Electric "magspeed" hoist control system. In this system which

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includes two electro-mechanical brakes in series, spring force holds the brakes engaged while DC solenoids, energized when the hoist: motor is energized, disengage the brakes.

The modification which added the slow speed hoist capability included insta11ing additional contactors in the brake solenoid power circuit to energize the solenoids when the low speed hoist motor was energized.

The original hoist control system design utilized a single Size 2 DC contactor (two contacts in series) in the solenoid ~ ~

circuit. The design modification added a circuit in parallel with the original DC contactor which utilized four AC rated Size 1 single contacts in a series-parallel array to distribute current carrying and interrupting burden.

Initial experience. with the modified hoist control system at Dresden showed that the circuit interrupting capacity of the series-paxallel array was marginal. On several occasions when the low apeed motor was stopped in the lowering mode, the solenoid circuit contacts arced resulting in power being supplied to the .solenoids long enough so that the load dropped some distance before the brakes engaged. Over travel of as much as 15 inches was reported, but no damage to hoist or load was found.

The crane manufacturer's representatives have advised the NRC that the proposed corrective action is to install a single Size 2 DC contactor (two contacts in series) with arc suppressors, the same as originally provided in the General Electric design, in place of the added four AC rated contacts.

The original contactor in the normal speed control circuit has shown satisfactory service since initial operation of the plant in 1969.

0 IE Bulletin No. 76-07 July 28, 1976 ACTION TO BE TAKEN BY LICENSEE:

1. Determine and report to this office within 20 days the following information:

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(a) -

Have you made, or do you plan to make modifications to the hoist control for your installed c'ranes similar to the described modifications?

(b) If such modifications have been made, or are planned, identify changes required in brake power and control circuitry?

(c) What steps have been taken or are planned, to provide assurance that brake power contactors are adequate for the service?

2. If modifications are planned, provide the schedule for completion and a brief description of your-plans for design review and functional testing.

Your response should be submitted to the Director of this Office,- with a copy to the Director, Division of Reactor Inspection Programs, Office of Inspection. and Enforcement, U. S. Nuclear Regulatory Commission, 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).

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