ML20151T309

Forwards Preventive Maint Abstract Review of & Description of Final Proposed Preventive Maint Program for CRD & Orificing Assembly Preventive Maint Program

ML20151T309
Person / Time
Site:	Fort Saint Vrain
Issue date:	02/03/1986
From:	Gahm J PUBLIC SERVICE CO. OF COLORADO
To:	Berkow H Office of Nuclear Reactor Regulation
References
P-86078, TAC-61066, NUDOCS 8602100222
Download: ML20151T309 (27)

Text

m O PublicService -.

Company of Colorado 16805 WCR 19 1/2, Platteville, Colorado 80651 February 3,1986 Fort St. Vrain Unit No. 1 P-86078 Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 ATTENTION: Mr. H.N. Berkow, Project Director Standardization and Special Projects Directorate Docket No. 50-267

SUBJECT:

CONTROL R0D DRIVE AND ORIFICING ASSEMBLY (CRD0A) PREVENTIVE MAINTENANCE PROGRAM

REFERENCE:

(1) PSC Letter, Gahm to Martin, dated 1/31/85 (P-85040)

(2) PSC Letter, Gahm ta Martin, dated 2/3/85(P-85046)

(3) NRC Letter, Johnson to Lee, dated 7/12/85 (G-85269)

(4) PSC Letter, Brey to

- Johnson, dated lhg2]gggggggg 7 6/14/85 (P-85199)

P (5) PSC Letter, Brey to Berkow, dated 12/27/85(P-85485)

Dear Mr. Berkow:

In the referenced attachments, PSC agreed to provide NRC with a proposal for a comprehensive CRD0A preventive maintenance program \

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7 which would assure all safety functions of the CRD0As.

A previous submittal (Reference 2), summarized a tentative program based on maintenance and failure history of CRDOAs from installation in the PCRV through the failures experienced in the latter part of 1984, which led to the CRD0A Refurbishment Program completed in June of 1985. This submittal updates that proposal with additional information obtained from the CRDOA Refurbishment Program in addition to engineering analyses underway to resolve specific performance problems.

Enclosed are three attachments: (1) Preventive Maintenance Abstract, (2) Review of Reference 2, and (3) Description of Final Proposed Preventive Maintenance Program.

We hope you will find this submittal responsive to your concerns. If you have any questions or comments, please call Mr. Mike Holmes at (303) 480-6960.

Sincerely, zw.Cd.nfyAalb//fL J.W. Gahm, Manager, Nuclear Production Fort St. Vrain Nuclear Generating Station JWG:JKE;jlr Attachments (1)' Preventive Maintenance Abstract (2) Review of Reference 2 (3) Description of Final Proposed Preventive Maintenance Program

ATTACHMENT 1 PREVENTIVE MAINTENANCE ABSTRACT PSC submitted (References 1 and 2) a tentative proposal for a preventive maintenance (PM) program for the Fort St. Vrain Control Rod Drive and Orificing Assemblies (CRDOAs). At the time submitted, the best available information was used as a basis for potential PM activities, recognizing that the experience and observations from the CRD0A Refurbishment Program would require incorporation into the final program.

This report discusses the original proposal in light of the experience gained in the CRD0A Refurbishment Program and the final proposed PM program, its requirements and basis.

The objective of this program is to take current best-available information and use this as the basis for a preventive / predictive maintenance program that will ensure all critical performance requirements of the CRD0As. This program will also provide indication of bearing performance as requested by the NRC (Reference 3).

y ATTACHMENT 2 REVIEW 0F REFERENCE 2 This attachment presents the potential PM activities from Reference 2 with an evaluation of the relevance of each item set off below. This review updates the . original proposal based on CRD0A refurbishment observations-and other engineering reviews.

I. PREVENTIVE MAINTENANCE (PM) PROGRAM GENERAL OVERVIEW OF POTENTIAL PM ACTIVITIES A. SHIM MOTOR /8 RAKE ASSEMBLY

1. Visual Examination

a. Pinion gear o This gear is the highest speed gear and displays the highest rate of wear.

PM Visual examination when overhauling the shim motor; replacement based on observation of significant wear,

b. Motor bearings o Visual examination of motor bearings is not adequate. Acceptable performance should be based on test for " smoothness", and torque to turn for the assembled motor / brake assembly.

PM Bearing examination and replacement when overhauling the shim motor. . Bearing acceptance for the overhauled motor based on turning smoothness and torque requirements,

c. Brake pads o No brake pad or other failures in the brake assembly that could be related to a failure to scram condition were found.

PM Visual examination of brake pads for residues based on the shim motor overhaul frequency.

Reconditioning and replacement if necessary.

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2. Test - as left (following maintenance)

a. Dynamometer o The dynamometer test considered is not sensitive enough to provide information relating to scram capability. Although good for determining motor load capability, shim motors have adequate load design margin.

PM No dynamometer test.

b. Torque to rotate - removed from CRD0A o Torque to rotate the shim motor / brake assembly when removed from the CR0 gives a good indication of shim motor / brake condition, and especially that of the shim motor bearings. This test gives both a torque to turn and a variance about this value that combined are indicative of shim motor bearing performance.

PM Measure torque to rotate the shim motor / brake assembly when removed during overhaul of the shim motor to determine acceptability of the bearings for reuse and to ensure final performance adequacy, c, Torque to rotate.- installed on CRD0A o Torque required to rotate with the shim motor / brake assembly installed gives a good indication of both overall resistance losses in the entire train and the actual transmitted torque with the load on the cables. Problems with this measurement are related to a requirement to have the cables at a known position in order to determine the exact moment applied to the cable drum sheeve. When this position is accurately determined (as off rod potentiometers), this is a very sensitive test.

o With the rod absorbers hanging fully down, with no moment applied to the cable drum sheeve, this test allows determination of overall drive train (including the shim motor / brake assembly) resistance to motion.

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PM Incorporate this test into the step wise determination of the need to perform drive train (200 Assembly) overhaul.

d. Back-EMF (scram generated braking voltage) o The Back-EMF (scram generated braking voltage) test provides a good indication of motor / drive train performance. This test will not be discussed further, as it is still subject to development and will be discussed in separate submittals.

PM No recommendation at this time.

3. Shim Motor Bearings

a. Clean / replace as required o Performance of shim motor bearings can be determined under A.2.b above. Qualitative tests to determine bearing smoothness could be included here, but would be duplicatous.

PM No specific requirement. Shim motor / brake overhaul procedures will call for rejection

o. any bearings not meeting smoothness requirements (compared to a standard). Other PM activities will serve to identify bearing performance problems.

4. Electrical.

a. Megger motor (insulation test) o Meggering of the shim motor windings will provide an indication of electrical resistance breakdown. This aspect of motor performance ias no effect on the capability to scram - shorted windings will only result in less dynamic braking.

PM Incorporate into a long term program to monitor degradation of electrical insulation to determine shim motor overhaul need.

b. Dynamometer (load capability) o As indicated in A.2.a, this test is not sensitive enough for determining scram

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capability', and is not as good as the Wattage Test for monitoring general load capability.

PM Not included in any activities.

c. Megger brake windings (insulation test) o Brake winding meggering will provide- an indication of _ brake winding electrical resistance breakdown. This aspect of brake performance has no effect on the capability to scram, as shorted windings will not develop adequate force to apply the brake.

PM This activity will be incorporated into a long term program to monitor degradation of electrical insulation to determine shim motor overhaul need.

B. DRIVE TRAIN

1. Visual Examination of exterior o Visual examination of the exterior of the drive train, both direct and through ports, gives a good indication of the degree of general corrosion and degradation.

Accessible gears and bearings can be examined for wear, corrosion, and lubrication loss.

This visual examination, in conjunction with other resistance measurement tests, will give a_ good indication of the need to perform 200 Assembly drive overhaul.

PM Incorporate into the CRD0A overhaul as a trigger to perform complete drive train overhaul.

2. Torque - delivered (rods on) measurement

a. Torque to rotate -

motor installed on CRD0A -

through shim motor rotor shaft (This is the same as item A.2.c, above) o This item is discussed under A.2.c.

Essentially, with the shim motor / brake assembly installed, performance adequacy for the 200 Assembly drive train can be determined.

PM See A.2.c.

b. Back-EMF (scram generated braking voltage) o This item is covered under A.2.d. This test allows monitoring of 200 Assembly drive train performance.

PM See A.2.d.

C. CABLE

1. Visual examination a Visual examination of cable should be performed on an accessible cable section to determine residues that may adversely affect cable performance. Radiological and other conditions make this examination difficult to perform, unless physical removal of the cable is done. Replacement of Stainless Steel with Inconel is expected to resolve the previously observed failures. Degradation of cable is expected to occur very slowly, if at all.

PM Perform . visual examination of a single cable for deterioration or deposits on an intermediate basis.

2. Surface wipe analysis o Surface wipe analysis for contaminants was not performed routinely during refurbishment.

This. may yield valuable information if residues are observed during visual examination, but may be impossible to perform under the radiological conditions encountered.

PM. Perform this analysis as radiological conditions allow when residues indicative of cable degradation are observed in conjunction with C.I.

3. Replace one cable every 3rd refueling cycle to allow:

a. Detailed visual examination

b. Meta 11ographic examination

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c. Pull test o This item was included to consider the possibility that a susceptible material might

be required for design purposes to replace the Stainless Steel. cable. Since Inconel, a l non-chloride stress corrosion susceptible l material, was selected, no activity is required.

PM None.

D. RESERVE SHUTDOWN SYSTEM

1. Hopper

a. Visual examination a Visual examination of the hopper or any blown RSD material allows' determination of agglomeration tendencies or material transport, such as B 20 3.

PM Any time RSD material is blown, visually examine the hopper, as well as the blown material .

2. Material

[ a. Sample removal - visual examination a Removal of the RSD material by vacuum to verify lack of agglomeration should be performed on one CRD on a periodic basis to verify no agglomeration.

l PM Once every two refueling cycles, remove RSD Material with a vacuum and examine.

b. Sample analysis - select CRD0As o Visual examination of non-blown RSD material for evidence of deposits should be performed on one CRD on a periodic basis to verify no l significant deposits.

I PM Once every two refueling cycles, visually examine removed RSD Material for deposits; analyze any significant deposits observed for

type of material and agglomeration tendency.

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3. Pressure switch

a. Functional Test - Surveillance Requirement o The pressure switch serves no safety role -

it merely allows demonstration of operability of the RSD system by allowing the demonstration of the capability of pressurizing the hopper.

PM An existing Surveillance (SR) requirement serves as PM activity to demonstrate operability. . LC0 4.1.902: Channel Calibration of .the RSD hopper pressure switches.

4. Valves

a. None o N/A

5. RSD System

a. Functional test (blow rupture disk) - Surveillance Requirement o Demonstration of operability of the RSD System is already addressed by Surveillance Requirement. Except for agglomeration, no problems with this system have been observed.

PM LC0 4.1.8E SR 4.1.904 E. DOSITION POTENTI0 METERS - R00 PAIR

1. Visual Inspection o- Position potentiometers should be replaced on the 6 cycle refueling basis schedule.

PM No visual inspection requirement is necessary.

2. Test o Performance of rod position potentiometers is ensured by existing surveillance

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E requirements.

PM No additional test activity is needed. LCO 3.1.2/SR 4.1.2 covers potentiometer performance between service periods.

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3. Replace based on service

a. Number of shims

b. Rod travel l c. Anomalous indication

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d. Other service parameters o The current rod position potentiometers need to be replaced based on a service interval reflecting use. No rod should see Regulating Rod Service for more than 1 of 6 cycles l between overhauls, due to potential for

, excessive potentiometer wear between

{ overhauls.

L PM Replace rod position potentiometers during CRDOA overhaul. Any failure or SR deficiency will require corrective maintenance to replace the position potentiometers. No special service conditions, other than that for the regulating rod, should be specified.

A design change to improve rod position potentiometer performance and life is expected to affect this interval. This should provide a poteptiometer more suitable for the potentially adverse environment seen in the PCRV (saturated helium).

F. LIMIT SWITCHES (2 each - slack cable, in, out, retract)

1. Visual Inspection

2. Test

3. Replace based on service

a. Time in reactor

b. Moistere i

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c. Anomalous behavior

.- o Limit switches currently need to be replaced based on the overhaul interval. Selected examination of replaced (or failed switches) to determine design adequacy and exposed environments needs to be continued. Evidence of incipient failure should be used to reevaluate- the replacement interval, or propose design alternatives.

o Currently, there is a design review underway to determine the feasibility of replacing the In/Out limit switches with proximiters not requiring physical contact to actuate. This would replace 4 of 8 limit switches. The remaining limit switches will also have a design modification that is expected to resolve failures occurring with the Full Retract limit switches. The Slack Cable limit switches do not have any significant failure history.

PM Pending further review and evaluation, all

. limit switches will be replaced based on the overhaul cycle. After justification, the interval for Slack Cable and Full Retract limit switches may be reduced to reflect the actual failure history. In this case, visual

. inspection of these limit switches will be performed. If rod In/0ut limit switches are modified to proximiters, this activity will not apply to the proximiters, which are non-mechanical in nature.

G. ORIFICE DRIVE MOTOR ASSEMBLY

1. Visual o Visual examination of the Orifice Drive Mechanism (ODM) is a good indicator of condition. Based on this, a decision to overhaul the assembly can be made.

PM Visually examine the ODM, based on the CRD0A overhaul interval.

2. Bench Test

o Bench test of the ODM indicates proper meshing and lash of gears. -This test can be performed with the assembly installed.

PM Bench test the ODM, based on the CRD0A overhaul interval.

3. Clean and lube (dry) o Complete overhaul of the ODM (motor and gear train) should be based on performance of G.1 or G.2.

PM Perform. complete overhaul as triggered by results of G.1 and G.2.

4. Replace support nut o Engineering and failure evaluations have indicated no need to replace the support nut.

PM No program inclusion.

5. Orifice Position Potentiometer replacement a The orifice position potentiometers are similar in construction to the rod position potentiometers. Replacement based on service life needs to be addressed.

PM Replace orifice position potentiometers based on the refueling cycle overhaul, unless failure trending or potentiometer modification justifies a less frequent interval.

H. ORIFICE ORIVE LEAD SCREW

1. Visual - as found a No visual examination is possible without first opening the assembly up - a very tedious procedure. Prior to performing this, a determination of performance should be made by determining driving torque requirement from the lead screw. During refurbishment, a strong correspondence between pre- and post-refurbishment- condition and driving torques for the mechanism was found. This should form the basis for a Predictive Maintenance (PDM) determination of need for

overhaul. If the torque requirement is excessive, overhaul should be performed. No visual examination need occur in this event. l PM Determine the torque requirement to drive the Orifice Valve from the lead screw in the overhaul program. Excessive torque requirements will trigger lead screw refurbishment. No visual examination is required.

2. Clean physical o If indicated, cleaning would be performed in conjunction with lead screw refurbishment.

PM No specific requirement for cleaning.

3. Dye Penetrant testing l o If- a need for overhaul was indicated, then penetrant testing of the lead screw or other i suitable NDE should be performed.

PM Included with overhaul if required under_ item H.1.

4. Lubricate and exercise t o This can only be done in conjunction with i overhaul. Only by disassembly can suitable r dry lubrication be performed.

PM No specific inclusion; if indicated, this would be performed in conjunction with lead screw refurbishment.

I. LOWER SEAL

1. Visual o Visual examination of the lower seal should be performed on a refueling cycle basis.

PM Perform a visual examination of the lower seal for refurbished CRDOAs on a refueling cycle basis.

2. Clean physical, wipe

r-o Cleaning -of the lower seal should be performed based on a determination from I.1.

Successful completion of I.1 should provide a basis for delaying I.2 until the next refueling cycle.

PM Perform cleaning based on visual examination results from I.1.

3. Clean - body housing o No need for this was found during CRD0A refurbishment.

PM No recommended action.

J. PRIMARY SEAL - 600 ASSEMBLY

1. Visual

2. Clean - wipe o Based on the refueling basis, the lower sealing surface, upon which the CRDOA is supported, should be visually examined for damage. At this time it should also 'be cleaned.

PM Incorporate on a refueling cycle basis.

3. Clean a Penetration cleaning should be performed on a refueling cycle basis. Equipment Storage Well (ESW) penetration cleaning should be performed whenever a CRD is removed from an ESW, or just prior to CRD0A installation.

PM Include on a refueling basis for Reactor penetrations. Make a routine activity during normal equipment movements.

4. Lifetime evaluation possible replacement o Evaluation of a modified 200 Assembly seal is underway, based upon ease of installation.

considerations. Should a seal modification result, these items would require re-evaluation.

PM N/A All penetration seals are tested for sealing adequacy by leak rate tests, hence these items are not justified except to the extent they eliminate rework due to faulty seals.

K. PRIMARY SEAL - 200 ASSEMBLY

1. Visual

2. Clean

3. Clean - mating surface o The 200 Assembly Primary seal should be examined based upon the refurbishment cycle.

This should include mating surfaces, and cleaning of both.

PM During the refurbishment, visually examine and clean both 200 Assembly sealing surfaces.

4. Lifetime evaluation possible replacement o Based on design life, the primary seal

.o-rings should be replaced during refurbishment.

PM Current design life.is adequate for the life of the mechanism. Engineering recommendations for -replacement will be incorporated into the PM interval as they are available.

L. CHECK VALVES - (RSD, CRD0A Purge)

1. Visual o Check valves will be replaced with refurbished, tested valves.

PM This item is covered as an existing SR. No other program is recommended.

2. Test o Check for proper orientation is currently performed as a special test (RSD and helium purge). Leak rate monitoring is done under

the SR.

PM Performance of existing orientation checks and leak rate determination will be retained.

M. CABLE SEALS

1. As determined by observed elevated / abnormal housing temperatures o No evidence of any cable seal problems were ever noted. This item should be dropped from PM consideration.

PM No program inclusion.

N. ORIFICE MOTOR PLATE SEALS

1. Visual

2. Clean o There is no experience or recommendations for PM on these. fio problems are currently anticipated.

PM No program inclusion recommended. Procedures will address normal good practices for disassembly.

O. WINDOW SEALS

1. Visual

2. Clean

3. Gasket material o There is no experience or recommendations for PM on these. No problems are currently anticipated.

PM No program inclusion recommended. Procedures will address normal -good- practices for disassembly.

P. MCC CAPACITORS

1. Test

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o The MCC capacitors may be checked for deterioration electrically. However, other requirements assure system performance and no significant failure experience has been observed.

PM No recommendations.

2. Shelf life / service life evalu~ation o MCC capacitors-have a limited service life.

PM Replace based on the service life interval.

Q. ELECTRICAL - POWER

1. Megger shim motor o This item was covered under A.4.a.

PM No additional recommendation.

2. Bench test shim motor (load capability) o This item is not required, as discussed in A.4.b.

PM None.

3. Megger brake windings o These items were covered under A.4.c.

PM No additional recommendation.

4. Bench test brake solenoid (load capability) o This item is not required, as indicated by no evidence of failures and demonstration of function in service.

PM No program inclusion.

5. Bench test stepping motor (load capability).

o This item should be performed as discussed under G.

PM No additional recommendations.

R. ELECTRICAL - INDICATION

1. In/Out Limit Switch Function - test redundancy when made up

2. Slack Cable - test redundancy when made up

-3. Full retract - N/A - normally not both made up o These items are addressed by SR requirements and under Position Potentiometers (E) and Limit Switches (F).

PM No additional recommendations.

S. BOLTS - EXPOSED TO PRIMARY COOLANT

1. Visual on selected bolts o No observations of bolting problems were observed from the CRDOA Refurbishment Program.

PM No program recommendations.

T. ABSORBER STRINGS

1. Visual o No visual examination _is needed. PDM, both wattage and Back EMF, will indicate any significant concerns.

PM No. program recommendation.

2. Lifetime evaluation possible replacement o Replacement based on service life will be performed.

PM -This will be addressed based solely upon residence time in 'the core and EFPD accumulation. This is already included in a CRDOA consumables program.

3. Shock absorber only replacement o Shock absorber only replacement is not considered an option at the current time.

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PM N/A.

II. PREDICTIVE MAINTENANCE (PDM) PROGRAM A. SHIM MOTOR / BRAKE ASSEMBLY AND GEAR TRAIN

1. Wattage -

outward shims - as found/as left; inward shims - as found/as left a The wattage test has been demonstrated viable for trending CRD performance. Collection of wattage data on a routine basis (quarterly) for steady conditions on standard-type shims could be used to establish baseline performance against which changes could be reviewed. The wattage test could be run in conjunction with the rod drop Surveillance Requirement (SR), and also with the scram time SR. Adverse trends would be used to trigger removal from the reactor for further evaluation and overhaul of degraded components.

141 Include quarterly rod performance trending into existing CRD0A Surveillance Requirements as separate, non-Technical Specification Tests.

2. Back-EMF voltages - during scram (and/or equivalent) -

as found/as left o Back EMF remains to be completely developed, but has great potential for PDM and flagging the need to initiate corrective maintenance.

PM Incorporate as technical details are resolved.

3. Delivered torque at motor - as found/as left

a. After CRD removed from PCRV during PM

b. Static - complete rotation, both directions o As indicated in items A.2.c and B.2.a of the PM section, delivered torque at the motor rotor was observed to be a significant parameter for monitoring CRDOA overall control rod . drive train performance. Based on this measurement, a rod flagged for overhaul by Wattage or Back EMF tests in the

reactor would be disassembled, torque tested prior. to shim motor overhaul, and then retested with a refurbished shim motor.

Determination of need to perform overall drive train (200 Assembly) overhaul can be based on objective evidence by tracking the torque loss to either the gear train or the shim motor. When gear train performance indicated the need, gear train overhaul would proceed.

PM Include as the parameter determining the requirement to perform 200 Assembly (drive train) overhaul, and final motor-drive train acceptability.

4. Scram times (SR 5.1.la-A)

a. Gross performance parameter (really monitors motor variation if done with constant capacitances) o Scram times, if measured with constant rod loads and known capacitance values, indicate changes in shim motor reluctance.

PM These items are covered currently by SR. No formal PM program inclusion.

5. Rod drop rate (SR 5.1.lb-M)

a. More sensitive than Item 4,, but less than Item 2.

o Rod drop rate should continue to be reviewed, primarily as it relates to item A.4 above.

PM Again, this item is currently covered by SR.

No formal PM program inclusion.

6. Torque to rotate motor / brake assembly - as found/as left

a. Removed from CRDOA (hence reflects motor bearings only)

b. Static - complete rotation o This item was covered under A.1.b, and A.2.b (PM section). Again, this is a key aspect of the PDM program as it determines the condition of the shim motor, exclusively, and in conjunction with measurement of delivered

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torque (A.3) of this section, determines the need for complete gear train refurbishment.

PM Include in the program.

ATTACHMENT 3 DESCRIPTION OF FINAL PROPOSED PREVENTIVE MAINTENANCE PROGRAM The Preventive Maintenance (PM) program is based upon maintaining Control Rod Drive and Orificing Assemblies (CRD0As) in an operable condition. Control rod operability ensures that a minimum shutdown margin is capable of being maintained. Interim Technical Specifications . 3/4.1.1, 3/4.1.2,.and 3/4.1.3 provide surveillance tests which indicate operational status. The information obtained from surveillance tests in conjunction with additional performance parameters provide the basis for the

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Predictive Maintenance (PDM) program. The additional performance parameters include shim motor wattage,- Back-EMF (during scram) testing, and torques during rotation of shim motor and drive train. The information obtained in the PDM program, trends, and inspections will provide the basis for the scope of the PM activities. Significant degradation of PDM parameters and observations during inspection will trigger ~ complete refurbishment of CRDOAs. PM activities shall be performed in accordance with Tech Spec 3/4.1.1 surveillance requirements. If PDM parameters indicate significant degradation prior to scheduled PM activities, the CRD0A will be inspected during the next refueling cycle.

Note that the use of the Back-EMF tests, Wattage tests, Delivered Torque tests, and Shim Motor Torque tests allow a systematic identification of components within the CRD0A with degraded performance, and focuses the maintenance activity on those parts of the CRD0A~which are degraded. This reflects the experience of the CRD0A Refurbishment Program, where deterioration of bearings and gears was most pronounced immediately at the shim motor, and was less significant further down the drive train. Note also, the proposed tests used to trigger PM activities are sensitive to bearing deterioration, as determined by the CRD0A Refurbishment Program.

I. PROPOSED PREVENTIVE MAINTENANCE ACTIVITIES NOTE: For discussion of activities see Attachment 2.

A. SHIM MOTOR / BRAKE ASSEMBLY

1. Visual Examination

a. Pinion gear

b. Brake pads

2. Test - as found/as left

a. Torqu'e to rotate - removed from CRDOA

b. Torque to rotate - installed on CRDOA

c. .Back-EMF (scram generated brakir.g voltage)

3. Electrical

a. Megger motor (insulation test)

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b. Megger brake windings (insulation test)

B. DRIVE TRAIN

1. Visual Examination of exterior

2. Torque - delivered (rods on) measurement

a. Torque to rotate - motor installed on CRD0A -

through shim motor rotor shaft (This is the same asitem'A.2.b,above).

b. Back-EMF (scram generated braking voltage)

C. CABLE

1. Visual examination

2. Surface wipe analysis D. RESERVE SHUTDOWN SYSTEM

1. Hopper

a. Visual examination

2. Material

a. Sample removal - visual examination

b. Sample analysis select CRD0As

3. Pressure switch

a. Functional test - Surveillance Requirement

4. Valves

a. None

5. RSD System

a. Functional test (blow rupture disk) - Surveillance Requirement E. POSITION POTENTI0 METERS - ROD PAIR

1. Test (LCO 3.1.2/SR 4.1.2)

2. Replace based on CRD0A overhaul interval F. LIMIT SWITCHES (2 each - Slack Cable, In/0ut, Retract)

1. Replace based on CRDOA overhaul interval (In/0ut) or other. considerations as justified (Slack Cable, Retract)

G. ORIFICE DRIVE MOTOR ASSEMBLY

1. Visual

2. Bench Test

3. Clean and lube (dry) - as required by results of G.1, G.2

4. Orifice position potentiometer replacement based on the overhaul interval H. ORIFICE DRIVE LEAD SCREW

1. Test - torque required to drive Orifice Valve

2. Clean physical - as required by results of H.1

3. Dye Penetrant testing - as required by results of H.1

4. Lubricate - as required by results of H.1 Items H.2, H.3, and H.4 are done together if warranted by H.1 I. LOWER ' SEAL

1. Visual

2. Clean physical, wipe - as required by I.1

F-J. PRIMARY SEAL - 600 ASSEMBLY

1. - Visual - (CRDOA and Penetration)

2. Clean CRD0A

3. Clean - Refueling Penetration K. PRIMARY SEAL - 200 ASSEMBLY

1. Visual

2. ' Clean - 200 Assembly

3. Clean - mating surface

4. Lifetime evaluation -

possible replacement replace during' refurbishment,-if required

-L. . CHECK VALVES - (RSD, CRD0A Purge)

1. Replace

2. Test - check for proper operation and leak rate M. MCC CAPACITORS

1. Shelf life / service life evaluation - -replace as required N. ELECTRICAL - POWER

1. Megger shim motor (test insulation deterioration) -

performed in A.3.a, above

. 2. Megger brake windings (test-insulation deterioration) -

performed in A.3.b, above

~0. TEMPERATURE SENSORS (RTD's).

1. Inspect for expoxy deterioration -

in response to request in Reference 3 II.-PROPOSED PREDICTIVE MAINTENANCE (PDM) PROGRAM A. SHIM MOTOR / BRAKE ASSEMBLY AND GEAR TRAIN

1. Wattage -

Outward shims -

as found/as left; Inward shims'- as found/as left n

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2. Back-EMF voltages - during scram.(and/or equivalent) -

as found/as left

3. Delivered torque at motor - as found/as left

a. After CRD removed from PCRV during PM

b. Static - complete rotation, both directions

4. Scram times (SR 5.1.la-A)

'5. Rod drop rate (SR 5.1.lb-M)

.6. Torque to rotate motor / brake assembly - as found/as left

a. ' Removed from CRD0A

b. Static - complete rotation