U-602605, Provides Addl Info Re 960222 Proposed Amend LS-94-004 to License NPF-62,revising TS 3.3.4.1, EOC Recirculation Pump Trip Instrumentation, in Response to NRC 960424 RAI

Provides Addl Info Re 960222 Proposed Amend LS-94-004 to License NPF-62,revising TS 3.3.4.1, EOC Recirculation Pump Trip Instrumentation, in Response to NRC 960424 RAI

ML20115B563
Person / Time
Site:	Clinton
Issue date:	07/04/1996
From:	Lyon M ILLINOIS POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L47-96(07-04)LP, L47-96(7-4)LP, U-602605, NUDOCS 9607100211
Download: ML20115B563 (28)

Text

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Ittinois Power Company 500 South 27th Street -

P.O. Box 511

• • • '"' S'525' 8 5 E NMS P(WWER U-602605 i

L47 96(07 -04 )LP SE.100s ,

July 4 1996 Docket No. 50-461 Document Control Desk '

Nudest Regulatory Commission <

W.tshington, D.C. 20555 -

Subject:

Clinton Power Station Response to Request for Additional Information Related to Proposed Amendment of Facility Operatina License No. NPF-62 (LS-94-004)

Dear Sir:

By letter dated February 22,1996 (Illinois Power (IP) letter number U-602522),

IP submitted an application for amendment of the Clinton Power Station (CPS) Operating License (License No. NPF-62) to incorporate a proposed change to the CPS Technical ,

Specifications (Proposed Change No. LS-94-004). IP proposed to revise Technical Specification (TS) 3.3.4.1, "End of Cycle Recirculation Pump Trip (EOC-RPT)

Instrumentation," specifically to delete Surveillance Requirement (SR) 3.3.4.1.6 which

. requires the RPT breaker interruption time to be determined at least once per 60 months.

To support review ofIP's application for amendment, the NRC has requested IP to provide additional information as requested within NRC letter, " Request For Additional Information Concerning Proposed Change Eliminating The End Of Cycle Recirculation  ;

Pump Trip Interruption Time Testing Requirements - Clinton Power Station, Unit No.1 (TAC No. M94888)," from D. V. Pickett, Senior Project Manager, dated April 24,1996.

This letter is provided in response to that request. Therefore, please find in the attachment to this letter (as supported by the attached enclosures) IP's response to each of the questions contained in the NRC's request for additional information.

Due to the potential to reduce refueling outage complexity and/or duration, as well as the significant resource savings that can be realized by implementation of the proposed change to delete Surveillance Requirement (SR) 3.3.4.1.6, IP is requesting that the 9607100211 960704 PDR ADOCK 05000461 7

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. i-U-602605 Page 2 application for amendment, as supported by this letter, be reviewed on a schedule sufficient to support the sixth refueling outage currently scheduled to begin October 13, 1996.

Sincerely yours,

?

Michael W. Lyon Director-Licensing j AJP/csm 4 Attachments cc: NRC Clinton Licensing Project Manager '

NRC Resident Office, V-690 Regional Administrator, Region III, USNRC  !

Illinois Department ofNuclear Safety l

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l Attachment to U-602605 LS-94-004 l Page 1 of 9 j f i By letter dated April 24,1996 the NRC requested additional information related to Illinois Power's (IP's) February 26,1996 request to amend the Operating License (Technical '

Specifications) for Clinton Power Station (CPS). The proposed change would eliminate the Surveillance Requirement for periodically measuring the breaker interruption time for j the reactor recirculation pump motor breakers which are designed to be rapidly and l automatically opened by the End-of-Cycle Recirculation Pump Trip (EOC-RPT) system i (in conjunction with a reactor scram) to mitigste the effects of a pressurization type l transient such as a turbine trip or generttor load rejection. Information in remonse to ,

I j each of the questions contained in the NRC's request for additional information is given below: l l

Ouestions and Resoonsta

1. "Please identify the breaker model and manufacture. This information is not l

stated in the request."

Resoonse: Each of the four EOC-RPT circuit breakers is a Westinghouse Class IE, safety-related, type 75DVP500. Each ofthe two Reactor Recirculation i i Pumps at CPS has two such safety-related circuit breakers in series with j pump power. (See Figure 1, Page 9 of 9 of this Attachment.) These circuit breakers are similar to the horizontal drawout magnetic-air type 75DHP500 breakers manufactured by Westinghouse; however, these

! circuit breakers differ in that they utilize vacuum interrupters instead of 2

pole pieces. The DVP line of circuit breakers is a first generation vacuum type. The breakers are each equipped with a spring-stored, energy closing mechanism similar to that utilized in DHP circuit breakers.

^

l 2. "Please provide a Failure Mode and Effects Analysis (FMEA) for the breaker for which this request is made. On page 4 of Attachment 2, second bullet,it

? Is stated:

The design of the breaker is such that there is seldom failure of the breaker to open v3 thin the vendor specified time limits that does not i.!se result in a failure of the breaker to operate. Problems with the mechanks of the breaker would most likely cause mechanical failures, not a degradation of performance that would cause the breaker to open in a time greater than the vendor specified time limit. So, while degradation of the breaker mechanism that would impact the mechanical opening time of the breaker may be pcssibic, the breaker mechanism would be expected to fail to operate rather than fail in a manner that

. . l Attachment to U-602605  :

LS-94-004 Page 2 of 9  ;

would be difficult for cperaton and maintenance  ;

> penonnel to recognize.

A failure which seldom occun will,in fact, occur. Since the failure anode determination has apparently been done by Blinois Power Co. (IP), the staff  !

would like to review the failure modes. In addition, the staff would like a more definitive, preferably numerical probability of failure to open within

! specified time limits without fsilure to operate than ' seldom' or 'most

likely'."

Response: The second bullet on page 4 of Attachment 2 ofIP's submittal was a  :

summary statement based on the vendor manual, past performance of  ;

i maintenance, actual operating experience, and engineeringjudgment. A 4

formal FMEA for the breakers was not provided by the vendor, but an analysis and discussion of breaker failure modes based on vendor 4

j information and IEEE 500-1984, "IEEE Guide to the Collection and j Presentation ofElectrical, Electronic, Sensing Component, and Mechanical j Equipment Reliability Data for Nuclear-Power Generating Stations," is provided below, Applicable failure modes that would render the DVP breakers inoperable  !

l j (with respect to opening of the breaker on demand) are a catastrophic 1 failure and a degraded type of failure:

(1) A catastrophic failure of the vacuum breaker to open on demand

would be caused by failure of the operating mechanism or vacuum intermpters. To maintain high performance reliability with respect to these potential failure modes, maintenance is performed on the

! breakers in accordance with vendor recommendations. Preventive maintenance tasks include checking the interrupter for vacuum and

' contact wear gap, checking and adjusting the mechanism latches, lubrication, and testing that includes megger and ductor testing.

(2) Degraded failure of the vacuum breaker to open, i.e., a slow trip, would be caused by degradation of the operating mechanism.

. Again, proper maintenance (the preventive tasks described above) prevents such faliures. Westinghouse instruction bulletin I.B. 32-253-3B includes a section on the mechanical timing of breakers which states, "The breakers are checked at the factory for contact l speed and contact bounce. These values do not change appreciably during the mechanical life of the breaker and are not considered as a part of the regular it.spection and maintenance program."

4

.. l Attachment to U-602605 LS-94-004 Page 3 of 9 There is no failure probability data available spe eHy for the DVP-type .

breakers. Industry data is available for failure rates of the DHP metal-clad drawout type breakers. This data can provide some perspective on the -

reliability of the DVP breakers, considering that the DVP breakers can be expected to be more reliable. (The DVP breakers utilize fewer moving parts due to the vacuum technology employed. Further, although CPS is .

E only in its sixth operating cycle, performance of the DVP breakers has bet a {

. excellent as no failures or degradation has occurred to date.) The IEEE  !

- failure rate data for the DHP breakers includes catastrophic, degraded and incipient modes of failure, but does not include a failure mode specifically identified as " failure to open within specified time limits." Nevertheless,  ;

the data can serve to provide a gauge of reliability. Per IEEE 500-1984, j the expected fdlure rate for the composite of all failure modes of metal '

clad drawout circuit bnakers (rated at greater than 600 volts) is 0.4 failures per one million hours. The IEEE failure number is conservative as

~! it includes data from Class-lE and Non-lE equipment, supplied from a

multitude ofmanufacturers.

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DHP breakers have notably good industry reliability. As specifically noted in EPRI/NMAC, Circuit BreakerMaintenance, Vol. 2, Part 3, April,1994, the Nuclear Plant Reliability Data System listed a total of only 30 failures.

' The EPRI/NMAC report also notes that, based on a review of the Nuclear 1 Regulatory Commission's Nuclear Document System (NUDOCS), no Informat. ion Event Bubetins (IEB's), Information Event Notices (IEN's), or l Information Event Circulars (IEC's) have been issued against Westinghouse

. medium-voltage circuit breakers.

I It should again be noted that due to redundancy in the EOC-RPT design l' (see Figure 1), failure of one DVP breaker would not result in a loss of tripping function. Based on redundant design, proper conservative ,

maintenance and CPS history failure, reasonable assurance exists that the i

. EOC-RPT breakers will perform their intended design function over the lifetime of the plant (without requiring periodic performance of a test to  !

! determine the breaker interruption time).

l 3. "Please provide a copy of the manufacturer's recommended maintenance,

! including mcommended maintenance intervals. In addition, please provide a '

copy of the Clinton Power Station required maintenance schedule. On page 2, it is stated:

i  ;

Discussions with the breaker manufacturer have ,

confirmed that measurement of the arc suppression time is unnecessary and that actual are suppression times are not subject to change for properly maintained

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l Attachment )

- to U-602605 i i

' LS-94-004

• Page 4 of 9 1 1 breakers. The robust design of the breakers provides 1

assurance of continued satisfactory performance.

Further, any degradation of the breaker that could j cause significant degradation of the are suppression i 1 9 time is prevented or detected by performance of recommended preventive maintenance and/or other required testing.  ;

4 This information will assist the staffin ensuring proper maintenance of the  :

breakers." g

! Response: IP has provided Section 6 of Westinghouse DVP Circuit Breaker Manual

I.E.32-253-3B, " Instructions for Porcel-line Type DVP Vacuum Circuit ,

Breakers," as Enclosure 1. This document provides a basis for an acceptable maintenance program for the breakers, including guidance for  ;

routine inspection of the breakers.

It may be noted that Section 6.3.1, " Routine Inspection Interval Based on Time," has been revised to incorporate vendor information provided to y CPS via Westinghouse Elect ic Corporation letter from Randy Faller,

Assistant Sales Engineer, dated February 22,1993, which is provided as Enclosure 2. This letter supported an evaluation performed in 1993 to

, justify making the inspection frequency for the DVP breakers to be the

- same as that for DHP breakers, i.e., once per three years.

I i Within the vendor's maintenance guidance provided in Enclosure 1, Subsection 6.6.2, " Mechanical Timing," states that the mechanical j operating speed of the breaker should be satisfactory as received from the vendor. The breakers are checked at the vendor's facility prior to shipment foi contact speed and contact bounce. These values do not change appreciably during the mechanical life of the breaker and are not considered J

part of the regular inspection and maintenance program With respect to

! the are suppression function, guidance for vacuum interrupter assembly j inspection and maintenance is provided in Section 6.6.1. This guidance

, includes use of a procedure described in Section 3.2 of the vendor instruction, which is a high pot test. The guidance also requires verifying wear gap within the interrupter assembly. Nowhere within Section 6 of the vendor instruction is arc suppression time response testing recommended as part of the routine maintenance or testing.

In response to the NRC's request to provide a copy of the CPS maintenance schedule for the EOC-RPT breakers, IP has provided copies of the applicable CPS Preventive Maintenance (PM) Task Descriptions as s

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Attachment to U-602605 LS-94-004 Page 5 of 9 Enclosure 3. The PM Task Descriptions (one for each breaker) may be summarized as follows:

Job No. Interval (oeriod) Inak Descriotion PEMRRA001 3 years Clean and Inspect PEMRRA002 3 years Clean and Inspect PEMRRA003 3 years Clean and Inspect PEMRRA004 3 years Clean and Inspect These " clean and inspect" PMs trigger performance of CPS Electrical  ;

Maintenance Procedure No. 8410.07. Selected pages from this procedure are provided in Enclosure 4 to indicate the scope and type of testing and  ;

maintenance performed per the procedure, consistent with vendor recommendations.

4. "Please provide a copy of past arc suppression time test results. On page 3 of i the IP request,it is stated:

1) A maximum time value of 95 milliseconds has been substantiated by IP during past surveillance testing at CPS,2) The vendor specified breaker interruption time is 50 milliseconds, which is much less than the proposed assumed vslue, and 3) Testing of the circuit breaker during equipment qualification testing confirmed an actual breaker interruption time of 24 to 34 milliseconds.

This information would lead the staff to conclude that during qualification F testing, times of 24 to 34 milliseconds were found, but since, during surveillance testing, times of up to 95 milliseconds were recorded. As the

vendor time requirement is stated as 50 milliseconds, a test result in excess of that time would lead to doubt about the test method, the vendor limit, or the breaker maintenance."

Response: The test results and dates for past arc suppression tests at CPS are given in Enclosure 5.

4 l According to vendor information, the rated interrupt time of the DVP breaker is 3 cycles, which is inclusive of the contact separation time. For

60 Hz applications,3 cycles is approximately 50 msec. To date, IP has l been unable to consistently obtain as low a response time as 50 milliseconds. This is due to the fact that the testing performed by IP is not equivalent to that originally performed by the manufacturer. The difference

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Attachment to U-602605 LS-94-004 Page 6 of 9 in test results is attributed to the difference in testing environment and the fact that the sensors and other test instrumentation used at CPS are not identical to those used by the manufacturer, as further explained below.

The purposes of the tests at CPS and those performed at the manufacturer's facility are different. The tests at the manufacturer's facility were performed to determine the precise capability characteristics of the breaker.

i The tests performed at CPS are for the purpose ofconfirming that the breaker performs within a given time limit. The equipment used at CPS to measure the arc suppression time is not as sophisticated as that used by the vendor, and limits the user's ability to precisely determine the arc suppression time. Nevertheless, the equipment is sufficient to determine a bounding time (with appropriate uncertainty / margin included) that is recorded as the " arc suppression time." Because the test methodology used at CPS is sufficient for demonstrating acceptable breaker performance to within a bounding time limit, the expense of doing more sophisticated or accurate testing comparable to that performed by the manufacturer has not been considered or required. Further description of the testing performed at CPS is given in the following paragraphs.

Arc Suppression time, for the purposes of the test, is defined as the time from trip coil actuation (energization) until cessation of the arc.

Temporary switches are installed to initiate the transient (i.e., to energize the trip coil). The switch contacts are monitored to determine the event start. A transducer monitors the current in the 6900-volt reactor recirculation pump motor circuit to determine when current flow ceases.

The timed response can vary from test to test and will vary from pump to pump. Time delays that increase the measured response of the breakers include delays caused by the sensors, instruments and test connections.

These time delays cause the overall test result to be conservative. For example, the transmission time from the temporary switch to the breaker trip coil is a source of test time delay that is not measured and does not get subtracted out of the result of the time response test. Another and significant source of test time delay is that pump coastdown induces some current into the circuit thereby artificially extending the measured time.

i The induced current in the circuit cannot be determined with insta!!ed plant equipment, and therefore, the associated delay time also does not get subtracted out of the result of the time response test. Further, some test time delay is introduced by the transducer. The transducer is a capacitive device that causes a time lag and for which the current may be assumed to reach zero in four to 4.6 time constants (somewhere between 95 and 98 percent of the total decay curve). This decay time has been measured at two to three times the expected arc suppression time. This transducer

Attachment to U-602605 LS-94-004 Page 7 of 9 delay time can be separately measured and is therefore subtracted from the test result, but some margin must still be included to account for uncertainty in the measurement of the transducer delay time.

To repeat, although there are inaccuracies associated with IP's test method utilized to date, these inaccuracies are accounted for, and appropriate  ;

margin is included in the test results. Testing at IP has established that 95 milliseconds is a conservative maximum response time and that this time  :

bo.mds the value determincd by the vendor design and testing. Thus, the i breaker is certain to respond whhin the 95 milliseconds that CPS proposes l to assume as the EOC-RPT maximum response time. l

5. "Please provide an analysis of the effect of an additional 5 seconds delay in the operation of the breaker on those transients or accidents where the EOC-RPT is required to mitigate the effect of the transient or accident."

Response: As emphasized in IP's submittal, it is expected that a properly maintained EOC-RPT circuit breaker will perform its intended function ofintermpting the current (including suppression of the resultant arc) when opening on demand, in about 50 milliseconds or less. However, as a conservative measure based on the results ofIP's test measurements performed to date, a bounding breaker intermption time of 95 milliseconds can be assumed.

As already noted, a DVP breaker is not expected to fail in a manner that would cause the breaker to open and suppress the resultant arc " slowly." It is therefore unrealistic to consider a 5-second delay (or any prolonged delay) in the operation of the breaker.

If a 5-second delay must be assumed, it should be noted that assuming such a delay time is equivalent to assuming no credit for the EOC-RPT function.

The EOC-RPT breaker interruption time is a component of the total time delay involved in tripping the reactor recirculation pumps in response to pressurization-type transients, i.e., main generator load rejection and turbine trip events. The assumed maximum recirculation pump trip delay time is specified in Chapter 15 of the USAR, Table 15.0-2, " Input Parameters And Initial Conditions For Transients." The total time specified I is equal to or less than 0.14 seconds (140 milliseconds).

As further described in the USAR, an automatic trip of the reactor recirculation pumps is designed to occur in conjunction with a reactor scrim to mitigate the effects of a generator load rejection or a turbine trip.

. Tr pping of the reactor recirculation pumps increases void content in the  ;

reactor coolant to offset the reactivity effects of void collapse, and thus I

, ensures that the resultant MCPR remains above an acceptable MCPR limit for such events. The EOC-RPT function (of tripping the reactor

o .

Attachment to U-602605 LS-94-004 Page 8 of 9 recirculation pumps) is expected to occur well within the time frame that the scram is expected to occur. Since control rods are expected to be fully ,

inserted within a time frame ofless than two seconds, assuming a five-second delay in the EOC-RPT response time is tantamount to discounting the EOC-RPT function.

It is acknowledged that the EOC-RPT function is required to mitigate the i effects of design basis events. However, as IP has noted, the proposed i deletion of the surveillance requirement to periodically measure the breaker interruption time will not result in any significant increase in the probability of the EOC-RPT failing to perform its intended function. The breakers have not been shown, and are not expected to degrade in a manner that  :

causes them to open and suppress the resultant arc in a slow manner.

Finally, it should again be noted that each reactor recirculation pump has two breakers in series. This further reduces the probability of a " slow" breaker affecting the overall EOC-RPT function, thus making any consideration of the effects of a 5-second delay in breaker operation even  ;

more unrealistic.

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Attachment to U-602605 LS-94-004 Page 9 of 9 ,

Figure 1 6.9 KV 4.16 KV f O O 6 CB3A(B) DVP CBIA(B) DHP l 0 o 1 E0C-RPT Breakers DVP LFMG A(B)' l CB4A(B) g O  !

O CB2A(B) DHP CB5A(B) DHP o  !

o  :

i RR  !

Motor RR Pump A(B) l 1

i RR Pump Motor Breakers j l

l I

i

l Enclosure 1 ,

to U-602605 LS-94-004 Page1of7 32 Section 6 - Maintenance This class of power circuit breaker is a protective device to pletely detailed records will facilitate evaluation of a prevent damage to more expensive apparatus and to rnain- breaker's condition or its changing condition. Such rec-tain continuity of electric power service. To maintain ords may include formal check lists, detailed descriptions greatest reliability the breaker should be inspected and of conditions found, notes on operating duty,. tests per-given all indicated maintenance on a regular schedule.The formed, maintenance procedures undertaken, etc.

Type DVP circuit breakers are designed to comply with Whether simple records or more complete records are kept standards performing switching operations based on max- is for the user to decide. Records can be very. helpful in imum of 2000 operations or once a year whichever comes determining both the types and extent of maintenance ,

first. which may be required and in determining whether in- l i spections should be scheduled more or less frequently, Actual inspection and maintenance will depend upon individual application conditions. Some atmospheric con-4 ditions such as extremes of dust and snoisture or corrosive 63 INSPECTIONSCIIEDULES gases might indicate inspection and maintenance at more fr:quent intervals than 2000 operations. Very clean and The schedule for routinely inspecting circuit breakers will ,

l dry conditions combined with low switching duty will depend on three inter related factors.

3 justify longer times between inspection and maintenance operations. With experience, each user can set an inspec. 1. Time since the last inspection.

tion and maintenance schedule which is most economical 2. Number of load switching operations since the last in-for the particular case.

spection.

. These breakeri are adjusted, inspected and tested at the 3. Number of short circuit switchMg operations since the factory in line with high standards of quality control and 1851 inspection.

reliability. They thould not require readjustments before placing in service. Do not change any adjustments, assem , Whichever of these three factors romes up first is the

, blies or parts unless there has been an obvious damage or factor which determines when an inspection should be incorrect adjustment. For instance, handling and transpor- made.

tation conditions could cause loss of adjustment or dam-age. The routine inspection interval should be based either on Time or on the Number of Anticipated Load Current Therefore, some inspection should be done on the Sw tching Operations whichever comes first. Superim-breaker immediately after receiving the breaker, posed on this routine inspection schedule is the require-ment that the breaker must be inspected after an accumu-6.1 INSPECTION / MAINTENANCE I .(OGRAMS lation of a number of short current switching operations if this occurs before the Time or Load Switching Operations in order to obtain the most effective use of this type of interval is completed.

maintenance instructions,it is important for the user to establish an inspection program that will permit him to 6.3.1 Routine Inspection Interval Based on Time routinely examine each circuit bseaker after regulasty scheduled intervals of operation as well as at discrete An mitial inspection at the end of the first year in service times when conditions sequiring particular maintenance is suggested because it provides an opportunity to evaluate procedures may be observed: Various suggestions are conditions at an early point in the life of a circuit breaker.

, noted below to be used in setting up suitable inspection / Based on conditions found, realistic decisions can be made maintenance programs. concerning the length of time for :,ucceeding inspection g4c, intervals. Ilowever, the intervaly not exceed one years, ledu MeJ hl. neu f~ % 22,t11) 6.2 INSPECTION / MAINTENANCE RECORDS 63.2 Routine Inspection Interval Based on Load Switching As a part of an ongoing inspection / maintenance program some fotm of recordkeeping is suggested. Records may The maximum number of load switching operations be-consist of a simple diary whose primary purpose is to tween scheduled inspections should not c'xceed the " Maxi-document ' that an established inspection / maintenance mum Number of Operations Between Servicing" as shown schedule is actually being followed, llowever, more com. in Table 4

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1 Enclosure 1 to U-602605  !

LS-94-004  :

i Page 2 of 7 I 33 i 4 s Table 4. Operations - Continuous Current Rating Basis j V

i Number of Op-=*lons .

Conthuous Max. No. i Operations No Isad Fuu Lead Inrush FuE toad Enrush Circuit Current  ;

Breaker Esting Between Mecksnical .

Duty fault Operation Nonfault Duty Type Amperes Servicing 1

10,000 1000 750 5000 3000 All DVP Vacuum 1200 2000 1000 750 3000 2000 Breakers 2000 2000 10A00 l

circuits and allowing for the contingency that a maximum  ;

. 'Ihe table lists recommended numbers ofload switch- '

system short circuit can occur at any time during the in.

ing operations. The different columns apply depending on terval, a practical inspection / maintenance guide can be  ;

whether the load switching duty includes inrush currents or not and whether h includes fault current switching or established. l d

not. 1 The following chart lists the level of the "most likely" 6.3.3 Inspection Interval Based on Short Circuit fault as a percentage "P" of the maxirnum short circuit Switching interrupting rating of the breaker. Each percentage "P" is coupled with an interval number "N" which is a sug-i.

. Since the short circuit switching requirements for circuit . gested number of"most likely" short circuit interruptions which the circuit breaker may be permitted to accumulate breakers may vary widely from one installation to an-

- other, i,oth in the number of short circuits which are within an established maintenance interval before it is re-moved from service for inspection and possible mainte-switched and in the magnitude of the short circuit current nance.

y to be interrupted, it is necessary to establish practical guidelines on which to determine how frequently a cir-Table S. Suggested Inspection / Maintenance Interval cuit breaker requires inspection to be certain that neces-sary maintenance is performed to keep the breaker in "Most Likely" Accumulated

good operating condition. Short Circuit

^ Short Intenuptions(N) )

Circuit breakers described in this instruction book have Circuit (P) been required to demonstrate that each ratingcan endure

} Greater an accumulation of short circuit interruptions totaling at

l' i least 400% of its respective maximum rated short circuit than 50%*

2 interrupting capability without maintenance being per- 50%

3

- formed. By relating the actual short circuit interruptions 40% ,

4 performed by a circuit breaker in the field to the capa- 35%

28.5% 6 buity demonstrated in design tests, a practical basis for I 24.5% 8 scheduling inspections and maintenance can be estab-20% andless 12 hshed. A key term which will be used here is the "most .

t likely" short circuit which can occur. While recognizing that a circuit breaker is applied on the basis that it has the

' NOTE: For a short circuit intenuption at P greater than 50%, it is strongly recommendea that inspection of capability of interrupting the largest short circuit which can occur at its location in an electrical system, experi- the circuit breaker always be made inunediately after a

', _ ence indicates that the probability is quite small that the single intenuption.

largest possible fault will occur during the operating life During the inspection following the accumulation of j of any given circuit breaker. Experience also shows that '

' many circuit breakers are applied where lower level short "N" interruptions, attention should be directed to the measurement of contact wear gaps. See item 3.3.Insulat-circuits will probably occur during the life of the circuit breaker with some degree of regularity or predictability. Ing members as well as general physical and mechanical .

By selecting inspection / maintenance intervals which are . condition should also be checked. (Refer to appropriate v

related to the possible occurrence of "most likely" short maintenance instructions in this instruction book for s

1

)

.. . l Enclosure 1 j

. to U-602605 i

• " LS-94-004 1

34 Page 3 of 7 guidance.) Several operations usIng control power are also 6.3.5 Total Breaker life advisable for a8-*: mechanism operation. Mether .

MBe operating duties are important considerationsin es- l maintenance is required or not, or whether maintenance procedures can be delayed unta the next scheduled rou.

tablishing an laspection/ maintenance program, it is tine laspection/ maintenance date, is a decision which equally important to consider factors which relate to the snust be made in each case on the basis of the conditions total life of a circuit breaker. Althoudi it is usual to think in terms of years in service, breaker life in temts of total found and operating experience.

accumulated operations is a more definitive parameter. A -

breaker which has passed the mid. point ofits operational Men a circuit breaker has accumulated 's total of "N" ' short circuit interruptions or less at percentage "P" life may reasonably require more frequent inspection and in any inspection interval, and after the circuit breaker different levels of maintenance than a newer breaker.

has been inspected and maintained when necessary, the circuit breaker may be returned to service to begin a new As illustrated by the chart " Operations - Continuous Current Rating Basis", a breaker wiE have a longer mech. ,

inspection interval and a new accumulation of"N""most  ;

likely" short circuit interruptions. Care should be exer- anical life span than an electrical life span. Time allowed ,

for maintenance may have to be extended to permit part cised to keep the selected "P" and "N" characteristic for each circuit breaker up4o.date with system growth. replacements and more extensive maintenance procedures during later life. An inspection / maintenance program will The maintenance interval chart is a suggested guide take these life factors into account.Where the selection of which has been developed on the basis of the demon- an initial inspection interval is often arbitrarily and con-strated endurance capability of the circuit breakers.De servatively established primarily due to a lack of operating number of operations given in the chart was conserva- experience, later life inspection / maintenance scheduling tively chosen to reduce the level of periodic maintenance can be more realistically deternuned based on the expe-rience which has accumulated. It is at this point where the rnd to give a longer life before major maintenance is re-

' advantages of well kept inspection / maintenance records quired.

will become manifest.

6.3.4 Service Conditions 6.3.6 Otanging Duty Considerations j The time or number of operations indicated above are A further consideration in an ongoing inspection / j based on the usual service conditions of ambient tempera-maintenance program can be generally categorized as tures in the range from plus 40'C to minus 30 C, alti. " changing duty". For some applications changes may oc-

$ tudes below 3300 feet (1000 meters), and relatively clean cut to increase breaker load current. For other applica-

- and dry conditions. tions changes may include more frequent switching or ex-Posure to more short circuit switching operations. Dirt Unusual service conditions such as exposure to damag.

and dust may accumulate faster or may change in content.

ing fumes and vapors, excessive or abrasive dust, explosive Damaging fumes or vapors may become more significant mixtures of dust or gases, steam, salt spr:y,and excessive r in their effects on breaker condition.De r fect of these rnoisture will usually reduce the time or number of switch. and other similar types of changes can be detected in an

ing operations between scheduled inspections. When un.

on going inspection program and inspection / maintenance

- usual conditions prevail, this information may be re. schedules originally developed may have to be modified i ferred to the nearest Westinghouse Sales Office for special from time to time as a result.

4 inspection / maintenance recommendations.

The foregoing three inspection schedules cannot be dis. 6.4 INSPECTION / MAINTENANCE PROGRAM cretely applied. Depending on the particular application, REVIEWS ene of the three operating conditions will predominate.

Michever cycle is completed first, time in service, num. In order to keep an ongoing inspection / maintenance pro-

. ber of load current switching operations, or short circuit gram up to date so that it reflects the experience accumu.

switching operations, will determine the completion of an lated, it is suggested that such programs be reviewed on a i inspection / maintenance interval. It will be necessary to periodic basis through the life of the circuit breaker.ne remove the breaker from service for inspection and neces- first review should be made following the initialinspec- q sary maintenance as soon as practical.

tion after a breaker is placed in service. Subsequent re-I R.37-753 3R -

. .. .. - .-. . . -. -- = . .-

Enchsure I to U-602605

' LS-94-004 l Page 4 of 7 35 views will depend on the type of application. For breakers 6.6.1 Vacuum Internspter Assembly inspection and

a Mainm- i which accumulate operations slowly (100 or less per year), subsequent reviews are suggested at seven to ten year intervals. For breakers which accumulate operations Check the vacuum lategrity of the interrupters every more rapidly, reviews are suggested after approximately year, or more frequently when dictated by the accumu.

25%,50%,75% and 100% of the number of operations lated switching frequencies shown in Table 5.

shown in the chart " Operations - Continuous Current D* P'rocedure outlined in Item 3.2 should be used to Rating Basis" under "No lead Mechanical Duty", have check dse vacuu;n integrity. It is unlikely to find that the been accumulated

• vacuum lategrity has been impaired. However, if it is im. ,

paired, the vacuum interrupter assembly should be re. l

• Pl aced according to procedure in item 6.7.1.

6.5 ROUTINEINSPECDON ,

Check the wear gap according to procedure in Item The maximum time between routine inspections as dic- 3.3. If the wear gap is less than .06", the vacuum inter-tated by either time in service, load current switching op- TUPter must be replaced.

erations, or short circuit switching should not .be ex.

l ceeded. Maintenance should include removal of the cir.

cult breaker from its switchgear housing, an inspection to 6.6.2 MechanicalTiming -

determine the condition of the circuit breaker,and clean.

ing to remove dust, dirt or other contaminants. Servicing ne mechanical operating speed of the breaker should be may also include exercising operations of the circuit satisfactory as received. De breakers are checked at the breaker, testing, adjusting, lubrication, tightening and factory for contact speed and contact bounce.nese val.

i other maintenance procedures as recommended in this ues do not change appreciably during the mechanicallife of the breaker and are not considered as part of the regu.

instruction book.

lar inspection and maintenance program.

6.5.1 Checking Contact Wear Gap The timing for contact part and close may be checked P'

Check wear gap in accordance with procedure outlined in by monitoring control circui: current, and using no rnore than 6 volts DC and one ampere through the vacuum in-item 3.3.

f terrupter contacts to indicate closed or open condition.

6.5.2 Mechanical Operation i i

' Typical time ranges for nominal control voltages are:

l Mechanically the circuit breaker should be quick, snappy e and positive in operation. Here should be no signs of a) Trip coil signal initiation to contact part: 24 34 m!Ili.

seconds. l sluggishness or hesitation. Should there be sluggishness in-dicated during an inspection, remove the barrier, and op. b) Close coil signal initiation to contact close: 40-65 j erste the circuit breaker slowly with the maintenance op.

millisec nds.

erating handle in order to identify the source of difficulty.

Refer to the section on Maintenance Procedures for cor- he speed of the vacuum interrupter contacts can be rective actions to be taken. Afte.r maintenance has been checked by using a potentiometer and an oscilloscope.

performed, a few exercieing operations using control ne potentiometer must have 2 inches of linear travel. i power are advisable. Any excesslubricant should be wiped It is fastened between the frame of the breaker and the off to prevent the accumulation of dust and dirt on and operating rod. De speed is then checked with an oscillo.

"**' " N"E P8"5- scope. He speeds should be in the following range: 2.5 ft/sec. to 3.5 ft/sec. closing,5.0 ft/sec. to 7.5 ft/sec.open.

4 Yg* I

6.6 MAINTENANCE PROCEDURES

' 6.6.3 Mechanism

Following are recommendations for the maintenance of particular breaker components. Rese include vacuum Close the breaker by spring power and open by normal interrupter assemblies, mechanisms, insulation and lubri- tripping action.Try charging the closing spring electrically cation. and also by hand. In either case, at the completion of the

Enclosure I to U-602605 l

1. LS-94-004 y Page 5 of 7 charging operation there should be an audible " click" as 64.5 LUBRICAT!ON I the crank arm goes over center.Wkh eteetdcel charging, '

the motor should automatically cut off at the sound of 6.6JJ Machenhm I

the dicit With hand distging, the handle wSI tend to run De most reliable pe formance on the stored energy snech.

free as the click is heard. anism can be obtained by tubdcation. AD parts which ,

require it are lubricated eh a molybduum disulphide in these operatiens, closing and opening should be gresse, Westinghouse M. No. 2701 Gs, when assembled.

snappy,without hesitation or sfuggishness. Some kems should be lubricated at regular maintenance intervals. Other parts normauy should require lubrication In addition to the above operational check, "the follow.

only after long penods of time. Otherwise, it should be Ing points should be checked: done at any time the breaker is slow or sluggish in opening or closing or where bearings may be clogged with dirt.

' l. With the breaker open and the closing spring charged, check for clearance between the tripping trigger and trip. After each laterval of 2000 Operations, the following ping latds rouer. Refer to Fig.106.%e trigger should not - hems should be lubricated with light machine o8 applied '

touch the roller. If adjustment is necessary see section on sparingly:

. Adgstments.

1. Front and rear trippinglatch rouers and pivot pin.

2. With breaker closed and closing spring charged, check

2. Tripping trigger pivot pin.

for clearance between the closing trigger and the closing j

3. Spring releaselatch roller and pivot pin, latch roller. Refer to l'ig. 9a. If adjustment is necessary )

4. Spring release trigger and pivot pin.'

see section on Adjustments.

5. Tripping cam pivot pin and restraining link pin.

3.1;ubricate the mechanism spuingly as described under 6.6.3.2 RollerBearings

~

Lubnication.  !

On the stored energy mechanisms there are roller bearings l 6.6.4 Insulation on the main shaft, crank shaft, connecting rod, and clos. l Insulation maintenance consists primarily of keeping th.e ing cam follower.

Insulating surfaces clean.nis can be done by wiping off Dese hearings are packed at the factory with a top the insulation each time the breaker is removed from the grade slow oxidizing grease which normally should be ef.

cell. fective for many years.ney should not be disturbed un.

less there is definite evidence of sluggishness or dirt, or In case there is any tightly adhering dirt that will not unless the parts are dismantled for some reason, come off by wiping,it can be removed with a mild solvent or water. Be sure to dry the insulation completely after )

If it is necessary to disassemble the mechanism, the this type of cleaning. bearings and related parts should be thoroughly cleaned of l

j old grease in a good grease solvent. DO NOT USE CAR.

6.6.4.1 CleaninghocedureforForcelaininsulation l BON TETRACHLORIDE. ney should then be washed in light machine oil until the cleaner is removed. After the If the porcelain insulation or the ceramic surface of the oil has drained off they should be packed with grease, vacuum interrupter requires cleaning,it is suggested that  ;

Westinghouse No.53'/01QB.

the surface to,be cleaned be wiped with a dry lint free l cloth or a dry paper towel. This surface can be washed oith distilled water but be 'sure that the surface is com. 6.6JJ Secondary Contacts

, pletely dry before placing the breaker in service. If a sol.

vent is required to cut the dirt, use Stoddards solvent Use only a very light coating of petrolatum.

Westinghouse 55812CA or commercial equivalent. Be sure the surface is completely dry before placing the breaker in 6.6.5.4 Drawour Disconnect Contact Fingers

. service. Do not use any type of detergent to wash the sur.

face of a porcelein insulator as detergents leave an ciec.

] -

Use only a very light costing of petrolatum.

trical conducting residue as they dry.

Enclosure 1 l to U-602605 LS-94-004  ;

I Page 6 of 7 3, V 6.7 REPAIR AND REPLACEMENT locking washers are compressed. De lower nut should be very tight.ne upper out is not tightened.

6.7.1 Vacuum Interrupter Assembly Replacement 6.7.2 Ressoval and Installation of Spring diarging The following procedure should be used to replace a vac. Motor uum bottle and set the wear gaps. See Figs. II and 26.

ne spring charging motor can be expected to last under

1. Take breaker out of the cell. normal conditions for the life of the breaker without re-quiring removal or replacement. However, if it does be-

2. Tilt back the barrier. come necessary to remove the spring chuging motor pro-ceed as follows: [

3. Remove "X" washers from operating rod pin at the ,

top of operatingrod. 1. Dist.harge all springs.

4. Using maintenance handle, slowly close breaker un'til 2. tut back barrier and remove its support pan.

the wear gap starts to appear. At the pointjust before the gap starts to appear, the pin should be easily removed 3. Place breaker on bench at convenient working height, i

from the operating rod, l

4. Disconnect motor leads.

S. Remove the two nuts holding the bottom conductors  ;

to the insulators. Remove the upper nut on the front in. 5. Remove four nuts holding motor assembly to mech.

sulator stud. anism. DO NOT REMOVE THE BOL'IE FROM THE

~

MECHANISM BACK PLATE.  ;

l

6. Uft off the interrupter assembly.

6. Remove motor assembly. l

7. Mount the new interrupter assembly by following the

" replacement procedure in reverse order. 7. Remove motor crank, Fig. 39, by striking sharp blow with soft mauet. Threads are right hand.

At this point wear gaps may be set if necessary as fol-lows: 8. Remove motor from mounting bracket.

8. Loosen the bottom nut on the bottom of the operating 9. Insta!! new motor in reverse order. BE SURE MOTOR rod. After the nut is loose, turn the nut down an vidi. CRANK ROLLER IS UNDER DRIVING PLATE, item I1, Fig.9a.

tional I/2 inch.

i

9. Attach the operating rod to the vacuum irrrrupter 6.7.3 Removal and Insta!!ation of Closing Spring j with the pin and new "X" washers. De breaker can be d

partlauy closed with the maintenance handle so that the Under normal conditions it should not be necessary to operating rod will reach the vacuum bottle to allow the change the closing spring during the useful life of the mechanism. If the spring does have to be changed, a Clos-g pin to be inserted.

ing Spring Removal Tool 592C864G01 is available from

10. Slowly close the breaker with the maintenance handle Westinghouse.

while watching the wear gap. If the gap gets larger than

.38" before the breaker latches close, do not continue To change the closing spring, refer to Figs. 34 and 35 )

closing with the handle, but ieopen breaker and spin the and proceed as follows:

upper nut on the end of the operating rod upward thereby l shortening the operating rod. If no gap appears at all when 1. Close and trip breaker manually to be sure all springs j the breaker is closed, the operating rods are too short and are discharged, the upper nut should be tumed down. Again slowly close the breaker with the maintenance handle until a gap of 2. Remove barrier.

.31" appears when the breaker is closed.Then tighten the lower nut on the bottom of the operating rod. (See 3. Assemble nut, thrust bearing, thrust washer, collar and j

Fig.13.) his results in a wear gap of about.25"when the tube on stud. Items 9,8,7,6,5 and 10, Fig. 35.

Enclosure I to U-602605

LS-94-004 38 Page 7 of 7 7

1. Secondary Contact Block

2. Ground Contact

3. Motor

4. Connecting Rod

"" - - 5. Oosing Spring Retaining Plate

' 6. Closing Spring Retainer Pin

7. Oosing Spring

8. Idler Link Pin q

9. Idler Unk l @ @

s @@@ @@

Fig.34 DVPBreaker0rassis: Rear View (396668)

4. Screw stud, Item 10, into end of connecting rod, item J] <

1, as far as it will go, Fig. 35.

S. Ifold stud firmly and remove idler link and pin.ltems p p "

l V./

8 and 9, Fig. 34.

l f NOTE: SPRING WILL MOVE EITilER UP OR DOWN h h jf s

13 ,g g,,,

WilEN IDLER LINK IS REMOVED. ,

l

6. Position the tube, item.5,so that the slots straddle pin f

' 4 thru the connecting rod I, Fig. 35.

[ ' '

l

7. Tighten nut 9 so that spring retainer 2 is moved away from pin 4, Fig. 35. h I

8. Drive pin 4 out of hole in connecting rod I, Fig. 35.

O I I

9. Iloid end of stud 10 with a wrench to keep it from .so n.t.

l N turning and unscrew nut 9 until closing spring 3 is com. ' ,g m2 U ? ,

l pletely free of tension, Fig. 35. Travel will be from 5 to - '

6.5 inches depending on breaker rating. 3 l -

10. Remove tool and spring.

C.5. Tube 9. Special Nut

1. Connecting Rods I 11. Reassemble in reverse order. 2. Spring Retainer 6. Couar 10. Stud

7. Thrust Washer 11. Lubricant G f 3. Spring

8. Thrust Bearing l 4. Pin

' Fig. 35 Closing Spring Removal Tool I N. 37 753 3B .

J - .. Enclosure 2 w* to ll-602605 ,

,- LS-94-004 I Page 1 of 3 j i

I

- Westinghouse

- * *S' cema w m

!- Electric Corporation ,

i February 22,1993 402-399-1935 P

4 l

Mr. George Kyle .

i Illinois Power Company

Clinton Station  ;

P.O. Box 678

! Clinton, IL- 61727 i

~

Subject:

DHP/DVP Breaker inspections  ;

Dear George,

. This letter is in response to the Illinois Power inquiry regarding inspection intervals for the types j DHP and DVP circuit breakers. Westinghouse *s position, as spelled out in the existing instruction '

i books, IB 32-253-4A & 4B/38, is presented in the synopsis below.

j This class of power circuit breakers is a protective device to prevent damage to more F expensive apparatus and to maintain continuity of electric power service. To maintain greater j reliability the breaker should be inspected and given all indicated maintenance on a regular i

schedule.

I l Type DHP and DVP circuit breakers are designed to have a long "in service" life with a 5

minimum of maintenance when operating duty is fairly ordinary or average. Because these t j breakers cre applied in a broad variety of applications under unique combinations of -

environmental conditions, each having operating duty requirements that can vary widely, it is  ;

! virtually impossinle to outline a specific maintenance schedule which would be universally appropriate for all ratings of circuit breakers in all types of applications. ,

The instruction books provide general guidelines for establishing inspection schedules and for  !

]' selecting specific maintenance procedures which are recommended to be used when particular conditions are observed. These guides are typified by a minimum number of rigid p requirements to permit persons familiar with circuit breaker operation and maintenance a i

- maximum amount of flexibility in developing a maintenance program consistent with good operating practices. i

, Actual inspection and maintenance will depend upon individual application conditions. Some ,

i atmosphere conditions such as extremes of dust and moisture or corrosive gases might

. indicate inspection and maintenance at more frequent intervals. Very clean and dry  !

- conditions combined with low switching duty will justify longer times between inspection and -i maintenance operations. With experience, each user can set an inspection and maintenance schedule which is best for his particular case.

f. -

Enclosure 2 to U-602605 LS-94-004 Page 2 of 3 in order to obtain the most effective use of this type of maintenance instructions it is important for the user to establish an inspection program that will permit him to routinely examino each circuit breaker after regularly scheduled interva!s of operation as well as at I discrete times when conditions requiring particular maintenance procedures may be observed.

An initial inspection at the end of tha first year in service is suggested because it provides an opportunity to evaluate conditions at an early point in the life of a circuit breaker. Based on conditions found, realistic decisions car Se made concerning the length of time for succeeding inspection intervals.

As a part of an ongoing inspection / maintenance program some form of record keeping is suggested. Records may consist of a simple diary whose primary purpose is to document that an established inspection / maintenance schedule is actually being followed. However, more completely detailed records will facilitate evaluation of a breaker's condition or its changing condition. Such records may include formal check lists, detailed descriptions of conditions found, notes on operating duty, tests performed, maintenance procedures undertaken, etc. Whether simple records or more complete records are kept is for the user to decide. Records can be very helpfulin determining both the types and extent of maintenance which may be required and in determining whether inspections should be scheduled more or less frequently.

The schedule for routinely inspecting circuit breakers will depend on three inter-related factors.

1. Time since the last inspection (per I.B. guidelines).

2. Number of load switching operations since the last inspection (Per I.B. guidelines).

3. Number of short circuit switching operations since the last inspection (Per I.B. guidelines).

Whichever of these three factors comes up first is the factor which determines when an inspection should be made.

The routine inspection interval should be based either on Time or on the Number of Anticipated Load Current Switching Operations whichever comes first. Superimposed on this routine inspection schedule is the requirement that the breaker must be inspection after an accumulation of a number of short current switching operations if this occurs before the Time or Load Switching Operations interval is completed.

As stated in the "DHP" breaker instruction book, IB 32-253-4A or 4B time intervals after the first initial inspection must not exceed three years. The instruction book, IB 32-253-3B, for the "DVP" breaker, states that this intervalis one year. Illinois Power has asked if the one year interval for ,

the DVP breaker can be extended to match the three year interval of the DHP. This would allow them to perform their inspections at the same time.

The guidelines given in the referenced Westinghouse instruction books (and summarized in the synopsis above) provide the user with the means to justify this extended interval based on his i own recorded experiences, for his breakers. Assuming that Illinois Power has accumulated this I 2

,.' .. . Enclosure 2 to U-602605-LS-94-004 Page 3 o'f:3 ,

actual experience, Westinghouse would not object to their extending the time interval of their DVP breakers to match that of their DHP breakers, I

Sincerely, Randy Faller Assistant Sales Engineer ,

cc Joe Beck - St. Louis Office  ;

cc Jan Creighton - Forest Hills cc- Tom Critchlow - Forest Hills i

6 i

t i

I i

i

[r 5

3 i

Enclosure 3 to U-602605 PPMMMPC PREVENTIVE MAINTENANCE DISPLAY MODE STATION: CL TASK DESCRIPTION PAGE:TVI LS-94-004 UN'T 01 SYS: AP EIN:l APO4EL TYPE: E JOB NO: PEMRRA001 Page1of2 PMLU: . .

CATEGORY:_ MWR/ TAO NO: 000001 JOB STATUS: C

. SD:RR REV NDR: 00 PM TYPE: R JOB PRJORITY: 00 EQUIP NAME: IB33000I A RX RECIRC PUMP I A MFR NAME : WESTINOllOUSE ELECTRIC CORP. MODEL: 75DVP500 EQUIP IDC : 26-U---I19-762 5AF: S IEEE: 1E SEIS:I CC:

• QA: B PVOP:

• LL:

• MRS: S EQ:

• UF:,_,

TASK DESC : CLEAN & INSPECT RR BKR Al (TYPE DVP)

IIIST RET: R CLEARANCE: Y COND REQD. EQUIP:__ SYS:_ UNIT: SD REF DOC / REG REQ:

PLANNER REMARKS:

REVIEWED: Y LEAD RESP:EM ORIO DEIT: MP MAINT TYPE:

SCllEDULING MODE:1 TASK FREQ:A INTERVAL: 003 DATES LAST DONE: LATE DATE: 070197 OlfrPUT FORM:

DATE DUE :100196 PCT OVERRUN: 25 PM MODE ID: NONE_

DATE SCllEDULED : DEFERRAL CD:,, KEY EVENT:_

DATE ASSIGNED : FOREMAN: FAILURE CODE:

DATE COMPLETED : RPRMN: PP;_

PPMMMPC PREVENTIVE MAINTENANCE DISPLAY MODE STATION: CL TASK DESCRIPTION PAGE: TOI UNIT:01 SYS: AP EIN:IAPOSEA TYPE: E JOB NO: PEMRRA002 PMDR#: - - CATEGORY: MWR/ TAG NO: 000001 JOB STATUS: C SD: RR REV NBR: 00 PM TYPE: R JOB PRIORITY: 00 EQUIP N AME: I1133C001B RX RECIRC PUMP 1 B MFR NAME : WESTINGilOUSE ELECTRIC CORP. MODEL: 75DVP500 EQUIP IDC : 26-V-105-762 SAF:S IEEE:IE SE!S: I CC:

• QA: B PVOP:

• LL:

• MRS: S EQ:

• UF: _

TASK DESC : CLEAN & INSPECT RR BKR U1 (TYPE DVP)  ;

illST RET: R I CLEARANCE: Y COND REQD. EQUIP: SYS: UNIT: SD REF DOC / REG REQ:

PLANNER REMARKS:

I REVIEWED: Y LEAD RESP; EM ORIO del'r: MP MAINT TYPE: 1 SCllEDULING MODE: 1 TASK FREQ:A INTERVAL: 003 I DATES LAST DONE: LATE DATE: 070197 OUTPLIT FORM: _ j DATE DUE :100196 PCT OVERRUN: 25 PM MODEID NONE DATE SCilEDULED : DEFERRAL CD:_ KEY EVENT:_.

DATE ASSIGNED : FOREMAN: FAILURE CODE:

DATE COMPLETED : RPRMN: PP:,

PPMMMPC PREVENTIVE MAINTENANCE DISPLAY MODE j STATION Cf. TASK DESCRIPTION PAGE: Tot UNIT: 01 SYS: RR LIN: lRR0 LEA TYPE: E Joll NO: PEMRRA003 PMDR #: - - CATEGORY: MWRfrAG NO: 000001 JOB STATUS. C SD RR REV NilR: 00 PM TYPE: R JOH PRIORITY: 00 EQUIP N AME: H33C1 A4 6900V HUS RR1 A HREAKER MFR NAME : WESTINGilOUSE ELECTRIC CORP. MODE!; 75DVP500 EQUIP IDC : 28-AG-123-781 SAF: S IEEE: IE SFIS.1 CC:

• QA: H PVOP:

• LL:

• MRS: S EQ Y UF: _

TASK DESC : CLEAN & INSPECT RR llRR A4 (TYPE DVP)

It!ST RET: R CLEARANCE: Y COND REQD - EQUIP: _ SYS. __ UNIT: SD REF DOC / REG REQ ___

PLANNER REMARKS:

REVIEWED. Y LEAD RESP: EM ORIG DEP1: MP MAINT TYPE:

SCllEDUl ING MODE.1 TASK FREQ. A INTERVAL: 003 DATES lAST DONE: LATE DATE: 070197 OUTPUT FORM _,

DATE DUE :100196 PCT OVERRUN: 25 PM MODE ID. NONE DATE SCllEDULED : DEFERRAL CD , KEY EVENT:_

DATE ASSIGNED : FOREMAN: FAILURE CODE:

DATE COMPLETED :_ _ RPRMN: _ _ _ _ __ _

PP:

.o Enclosure 3

~

PPMMMPC PREVENTIVE MAINTENANCE DISPLAY MODE i

a STATION: CL TASK DESCRIPTION PAGE:T01 LS-94-004 UNIT:01 SYS:RR EIN:lRR02EA TYPE: E JOB NO: PEMRRA004 '

PMDR W: . . CATEGORY: MWR/ RAG NO: 000001 JOB STATUS:C PaEe 2 of 2 SD: RR REV NBR:00 PM TYPE: R JOB PRIORITY:00 EQUIP NAME: B33CIB46900V BUS RRIB BREAKER MPR NAME : WESTINGHOUSE E!ICTRIC CORP. MODEL 75DVP500 EQUIP LDC : 28-AO--104--781 SAF: S IEEE: IE SEIS:I CC:' QA: B PVOP:

• 11:

• MRS: S EQ: Y UF:_ f TASK DESC : CLEAN & INSPECT RR BKR B4 (TYPE DVP)

' HIST RET:

R CLEARANCE: Y COND REQD . EQUIP: _ SYS:_ UNIT: SD l

REF DOC /REO REQ.

PLANNER REMARKS:

i  !

~

s REVIEWED: Y LEAD RESP: EM ORIO DEPT: MP MAINT TYPE:

j INTERVA!; 003 SCllEDULING MODE:1 TASK FREQ:A ,

,' DATES LAST DONE: LATE DATE:070197 OtTTPUT FORM:, j PM MODE ID: NONE  ;

DATE DUE : 100196 PCT OVERRUN: 25

• DATE SCl!EDULED : DEFERRAL CD. _ KEY EVENT: .,  !

DATE ASSIGNED : FOREMAN: FAILURE CODE: ,

DATE COMPLETED : RPRMN: PP:

o 1

l l

I 1

v

Enclosure 4 CPS No.

8410.07 to U-602605 LS-94-004 ILUNOIS POWEP CCMPAIN Page 1 of 4 OOCU..miU. W OL b' pf r. 2 K Ifdh CLINTON POWER STATION h' 7A' coNIndu FO COP #

pu,,, p#,.if aw c" PROCEDURE TITLE: REACTOR RECIRC 6900 VOLT VACUUM CIRCUIT BREAKER MAINTENANCE SCOPE OF REVISION: New procedure for Reactor Recirc 6900 Volt Vacuum Circuit Breaker to address ORM requirements, this procedure was previously part of CPS No. 9383.06.

CLASS CODE: SNOD ORIGINATED BY: Rich Slone WORD PROCESSING BY: Mary Sloan APPROVAL DATE: DEC 20 1995 O CHANGE NO. PAGES O CHANGE NO. PAGES O CHANGE NO. PAGES O CHANGE NO. PAGES O CHANGE NO. PAGES O CHANGE NO. PAGES O CHANGE NO. PAGES O CHANGE NO. PAGES O CIW4GE NO. _ PAGES G CHANGE NO. PAGES C

Page No. 1 of 42 Rev. No. 0

,a .

CPS No. 8410.07 Enclosure 4 ;

to U-602605 l TABLE OF CONTENTS LS-94-004

.h F Page 2 of 4 1.0 Purpose 2.0 Discussion / Definitions 3.0 Responsibility 4.0 Precautions 5.0 Prerequisites 6.0 Limitations 7.0 Materials and/or Test Equipment 8.0 Procedure 8.1 Parts Verification 8.2 Breaker Cubicle Inspection 8.3 DVP Circuit Breaker Cleaning and Inspection 8.4 Checking Interrupter For Vacuum 8.5 DVP Checking Contact Wear Gap Tripping Latch Clearance Adjustment

) 8.6 8.7 8.8 Motor Mounting Bolts Anti-Close Interlock Adjustment 8.9 Latch Check Switch Adjustment 8.10 Floor Tripper Adjustment 8.11 Lubrication 8.12 Testing 8.13 Restoration of Circuit Breaker 8.14 Vacuum Interrupter Assembly Replacement 8.15 Restoration of System 9.0 Acceptance Criteria 10.0 Final Conditions 11.0 References 12.0 Appendices - None 13.0 Documents

)

Page No. 2 of 42 Rev. No. O

e*

• CPS No. 8410.07 Enclosure 4 to U-602605 LS-94-004 8.11 Lubrication Page 3 of 4 Preventive Maintenance lubr':ation, refer to Figures 5, 6, and 10.

8.11.1 (Initial) Lubricate following mechanism type items with light machine oil (Special No. 522B) applied sparingly:

8.11.1.1 Front and rear tripping latch rollers and pivot pin.

l 8.11.1.2 Tripping trigger pivot pin.

8.11.1.3 Spring release latch roller and pivot pin.

8.11.1.4 Spring release trigger and pivot pin.

8.11.1.5 Tripping cam pivot pin and restraining link pin.

8.11.2 (Initial) Apply a light coating of petrolatum to secondary contacts, and drawout disconnect fingers, when required.

8.11.3 Cycle breaker open and closed a few times to distribute lubricant l I

8.12 Testing O 8.12.1 Megger circuit breaker using a test voltage of 1000 VDC per following steps. Megger readings shall be a minimum of 8 megohms.

8.12.1.1 (Record) With breaker OPEN measure resistance $A Line to & l A Load, $B Line to $B Load and $C Line to $C Load recording lowest reading obtained.

8.12.1.2 Close breaker.

8.12.1.3 (Record) With breaker CLOSED measure resistance of $A to

$B, $A to $C and $B to $C recording lowest reading obtained.

l 8.12.1.4 (Record) With breaker CLOSED measure resistance of $A to l bkr. frame, $B to bkr. frame and $C to bkr. frame, q recording lowest reading obtained.  !

l O

Page No. 22 of 42 Rev. No. O

Led No. 0410.U/

Enclosura 4 to U-602605 LS-94-004 i cC.12.2 Ductor Testing Page 4 of 4 Y (QV WIT) (Record) For DVP breaker, close circuit breaker l and perform ductor test on main contacts. Test leads shall be connected to upper and lower studs at points nearest l their connections to pole unit assemblies. (The exact test l point on each stud is an exposed ring of silver on the end l opposite the finger cluster). All individual contact resistance readings shall be less than 68 microhms. Record readings on CPS No. 8410.07C001.

8.13 Restoration of Circuit Breaker 8.13.1 (Initial) Reassemble barrier, arc chutes as applicable, barrier mounting pan and any other hardware or components disassembled or removed.

8.13.2 (Initial) Manually operate circuit breaker to verify that I breaker opens and closes satisfactory. l 8.13.3 (Record) Record EIN and calibration due date of Measuring and Test Equipment used.

I CAUTION d> Ensure MOC switch is not engaged unless authorized by Operations to prevent any inadvertent system actuations.

m 8.13.4 (Initial) Have Operations rack breaker to TEST position.

Electrically operate circuit breaker locally to verify breaker opens and closes satisfactory.

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• s Enclosure 5 to U-602605 LS-94-004 Page1 of1 EOC-RPT Brakar Interruption Time Test Results*

Rait Bkr 3A Bkr 3B Bkr 4B Bhr_M June 20,1987 61 milliseconds 94 milliseconds 92 milliseconds 59 milliseconds December 30,1988 94 milliseconds 93 milliseconds 94 milli =~=da 73 milliseconds April 25,1989 93 milliseconds 88 milliseconds 82 milliseconds 85 milliseconds October 13,1990 41 milliseconds Not Required Not Required 85 milliseconds June 7,1992 Not Required 47 milliseconds 83 milliseconds Not Required

• Prior to 1990, all b'reakers were tested during each refueling outage even though the Technical Specifications (TS) allowed testing to be done on a staggered test basis such that all trip channels were required to be tested at lead once per 36 months. IP's conservative interpretation of the TS was subsequently relaxed such that each breaker was then tested at a frequency ofonce per every other refueling outage (two per outage). In 1993, An-admant No.

74 to the CPS Operating License was issued which pennitted IP to extend the test interval for the breaker arc suppression measurement test to 60 months (not including allowed overrun).

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