IR 05000317/1986024
| ML20215F097 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 12/16/1986 |
| From: | Finkel A, Jerrica Johnson, Petrone C, Denise Wallace NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20215F080 | List: |
| References | |
| 50-317-86-24, 50-318-86-23, NUDOCS 8612230261 | |
| Download: ML20215F097 (14) | |
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U.S. NUCLEAR REGULATORY COMMISSION
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REGION I
Report Nos.
50-317/86-24 50-318/86-23 Docket Nos.
50-317 50-318 License Nos. DPR-53 DPR-69 Licensee: Baltimore Gas and Electric Company P.O. Box 1475 Baltimore, Maryland 21203 Facility Name: Calvert Cliffs Nuclear Power Plant, Units 1 and 2 Inspection At:
Lusby, Maryland Inspection Conducted: November 17-21, 1986 Inspectors:
/5l A.Finkel,[LeadReactorEngineer
/ date 0.
I.2ltLlVL m
C. Petrone, Lead Reactor Engineer dat;e h pds'ac
/2/M/26 D. Wallace, Reactor Engineer date Approved by:
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J. Johnson, Chief, Operational Programs date Section, Operations Branch, DRS Inspection Summary:
Routine, unannounced inspection on November 17-21, 1986 (Inspection Report Nos. 50-317/86-24 and 50-318/86-23).
l Areas Inspected: Maintenance procedures, electrical, mechanical and instrumen-tation maintenance and modification tasks and quality assurance / quality control interfaces.
Results: No violations were identified.
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DETAILS 1.0 Persons Contacted ~ ~^
Baltimore Gas and Electric Company
- M. Bowman, General Supervisor, Technical Services Engineering
- D. Butler, Assistant General Supervisor, Instrument and Electrical, Unit-1
- J. Carroll, Quality Assurance
- R. Gunn, Assistant General Supervisor, Instrument and Electrical, Unit-2
- L. Larragorte, Licensing Engineering
- J. Lemons, Manager Nuclear Operations Department
- W. Lippold, Manager Nuclear Engineering Services
- A. Marion, Licensing Engineering
- J. Moreira, General Supervisor, Electrical and Controls
- M. Robinson, General Supervisor, Quality Control and Support Services
- L. Russell, Manager Nuclear Maintenance
- R. Sheranko, General Supervisor Maintenance
- A. Thornton, General Supervisor Plant and Project Engineering United States Nuclear Regulatory Commission
- T. Foley, Senior Resident Inspector
- L. Tripp, Chief Projects Section The inspectors also held discussions with managers, supervisors and other licensee employees during the course of the inspection, including operations, technical and administrative personnel.
- Denotes those present at the exit meeting on November 21, 1986.
2.0 Licensee Action on Previous Inspection Findings and Licensee Event Reports (Closed) Violation (318/84-06-01):
Failure to perform acceptance NDE in accordnace with the applicable ASME code section.
Ten Unit 2 pipe-to-penetration welds were re-examined ultrasonically by Southwest Research Institute personnel to meet acceptance requirements of ASME Section III Division 1, Subsection NE, Class MC components,1977 Edition thru Winter 1977 addenda.
The inspector reviewed ultrasonic examination procedure 800-90 Revision 2, Deviation 1, data sheets associated with the ten welds, customer notification forms and indication resolution sheets which document the evaluation and disposition of examination results.
The inspector's review indicated that the licensee's commitments were met and the welds were acceptable per ASME Section III.
Based on the above, this item is closed.
(0 pen) LER-86-04 Calvert Cliffs Unit I reactor automatically tripped when a low Reactor Coolant Flow trip signal was initiated due to Reactor Coolant Pump (RCP)
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12 B breaker tripping open on a ground fault.
The fault was determined to be an internal _shgrt in the RCP surge capacitor.
(0 pen) LER-86-06 Calvert Cliffs Unit 2 reactor automatically tripped when a low Reactor Coolant Flow trip signal was initiated due to Reactor Coolant Pump 21 A breaker tripping open on a ground fault. This fault was also determined to be an internal short in the surge capacitor.
Corrective Action for LER's 86-04 and 86-06 In response to surge capacitor failures, the licensee is continuing to pursue the corrective actions specified in LER's 86-04 and 86-06.
License testing has indicated that the surge capacitors may be replaced with 100 pH inductors, which unlike the capacitors, may be moved out of the RCP bays where temperature and vibration would not challenge the capacitor design. The licensee is currently communicating with Westinghouse to ob-tain vendor. approval for replacing surge capacitors with inductors, and hopes to incorporate the modifications during future refueling outages.
These items remain open pending further review.
(0 pen) LER 86-07 Calvert Cliffs Unit 2 reactor was manually tripped due to a partial loss of secondary feed flow initiated by 21 Steam Generator Feed Pump (SGFP)
Turbine tripping. The event was caused by a technician jumpering across two terminals while investigating an inoperable remote alarm for the SGFP Turbine Control System. Troubleshooting revealed the local tachometer was a grounded model instead of the required ungrounded model. The effects of both the grounded tachometer and the jumpering of terminals lead to SGFP 21 tripping off-line.
l The inspector verified that the long term corrective actions specified in LER 86-07 are being incorporated into the operations and maintenance programs. These actions include:
An operations standing instruction dated October 7, 1986, that
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minimizes maintenance during full power operation that could result
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in a reactor trip, and Guidance for ground checks prior to maintenance as specified by the
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Trip Reduction Task Force. (Guidance scheduled to take effect during
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first half of 1987).
l This item remains open pending a review of the licensee's implementation.
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3.0 Maintenance Controls on Electrical and Mechanical Work Orders 3.1 PrograTiiiiETeliientati_on The inspector hele fiscussions with the electrical, instrumentation and mechanical maintenance supervisors, as well as quality control and maintenance personnel, to evaluate controls in place to identify schedule, track and document preventive and corrective maintenance performed on selected safety-related components.
The maintenance work orders, selected by the inspector, provided the following type of information:
A component data base number containing equipment nameplate
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data, Technical Specification schedules and maintenance status code; Storage of maintenance history by task, component and system;
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Identification of system, priorities, approvals and special
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instructioris, if required; and
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Scheduling of preventive and /or corrective maintenance tasks and procedures and associated documentation required for the task performance.
The inspector verified that the work orders reviewed contained as a minimum the data listed above.
No violations were identified.
3.2 Documentation Reviewed and Equipment Inspected The inspector witnessed the technician's specification review and testing of the components, during the corrective maintenance on the components listed below. At the completion of the maintenance task, the inspector reviewed the test results with the licensee's engineering personnel.
3.2.1 Documentation
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l The following criteria was part of the documentation required prior to and during the maintenance task performed by the~ licensee.
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Administrative approvals were obtained prior to l
initiation of work;
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Appropriate approved procedures, instructions and/or drawings were used; i _
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Post maintenance testing was required prior to
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returning equipment to service;
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Hold points were appropriately identified and
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implemented;
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Calibrated test equipment and tools used were identified and listed on the test sheet; Procedures and appropriate data sheets were properly
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completed;
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Acceptance criter?. v e identified and complied with; and Records were assembled, stored and retrievable as part
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of the maintenance work package.
No violations were identified 3.2.2 Maintenance Observations During the course of the above verification processes, the inspector witnessed and made observations of the following in progress maintenance activities:
Preventative Maintenance (PM-1-18-E-R.7)
No.14
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Inverter, Unit 1.
Due to failure of the ground detector relay (Potter-Brumfield KRP-11AG) in the No.14 Inverter unit, all inverter units for both Unit 1 and Unit 2 were checked. The four inverters of Unit 2 passed, but two of the four inverters in Unit I had a failure of the ground detector relay. This problem is discussed below in paragraph 3.2.2.1.
Surveillance Test Procedure (STP)
No.M-213-2,
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Calibration of Power Range Instruments to In-Core Instruments; and Surveillance Test Procedure (STP) No.M-650-2, #22
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Station Battery Performance Test.
3.2.2.1 No.21 Inverter During preventive maintenance of the No. 21 inverter, a ground detector relay (Potter Brumfield (CPR-11-AG 24VDC)
was shorted to ground and failed to operate. This was the first time an active relay in the inverter unit was tested for operation. A test of the four inverters in the Unit 1
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site indicated that two of the four inverters ground detector relays failed to operate. The failed relays were bench' t'ested and both operated correctly.
It appears that
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the relays were stuck due to infrequent operation, and in removing the relays there was sufficient vibration to each unit that they operated when an electrical short was applied during a bench test.
The two relays will be re-placed with like units.
The four inverters in the Unit 2 site were also tested and all operated satisfactorily.
The preventive maintenance procedure, PM No. 2-18-E-R-1, is being changed to require shorting of the ground fault detector relay during this test cycle.
To assure that this type of problem does not exist in other c;':uit designs, the 'icensee plans to review their design and procedures to verify that active components, which are not operated frequantly, will be tested during the prever.tive maintenance test cycle.
This item is considered unresolved pending NRC review of the licensee's program to identify the active components and the PM procedures required to verify the function of the components.
(50-317/86-23-01 and 50-318/86-24-01).
3.3 Seismic Monitoring Instrumentation System The inspector reviewed the seismic monitoring instrumentation data and hardware installation for compliance with the criteria of 10 CFR 100, Appendix A VI (a)(3),
" Required Seismic Instrumentation,"
Regulatory Guide 1.12 " Nuclear Power Plant Instrumentation for Earthquakes," and the facility Technical Specification (TS) table 4.3-4, 3.3.1 Seismic Instrumentation and Control Procedures The seismic monitoring instrumentation surveillance requirements are listed in the TS table 4.3-4.
The following data associated with functional testing of the instrumentation and sensors, selected by the inspector on a random basis, was reviewed:
Monthly testing channel checks; and
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Eighteen month calibration of the time history
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accelerographs, triaxial peak accelerographs and triaxial seismic switches.
In reviewing this test documentation, the inspector verified that the equipment met the acceptance criteria of surveillance procedure for the Model SMA-3/SMP-1 and the operability requirements of TS table 3.3-7.
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5,.7 2 S ismic Equipten+ Installation The'~" inspector verified the seismic instrumentation installation and location as listed in the Unit 1 Technical Specification for the Control Room Seismic Panel, Intake Structure and the Free Field components. A review of the equipment history records and test results indicated that the equipment performance was within the TS requirements.
No inadequacies were identified during this review.
3.4 Ground Isolation Investigation The licensee uses ground relays in their design for detection of ground faults on their d.c. bus lines. Although the typical ground relays will indicate that a ground fault is present the following problems exist:
Most ground relays in use require a significant level (e.g.,100
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milliamperes up to several amperes) of fault current for them to
actuate; and In complex control systems with numerous control branches off
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the main or bus, it is difficult to determine the branch in which the fault exists.
The licensee has a ground isolation program underway and the inspector witnessed the trouble shooting associated with the potential grounds existing in the annuciation system of Unit 1.
The d.c. power feed for this system was removed from Unit 2 bus No.21 and connected to the spare station battery system.
However, before the trouble shooting of the annuciation system began, the licensee con-nected recording devices on the spare d.c. battery system bus to es-tablish d.c. voltage levels. The inspector witnessed the maintenance effort associated with the installation of both the cables and the breaker box associated with this investigation.
To reduce the potential of ground detection equipment not working the licensee has taken the following steps:
The maintenance procedures are being changed to require a ground
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test verification on equipment during the as-found inspection which is to be repeated after maintenance work on the item is completed.
The inspector verified that training of the mainten-
ance personnel has taken place and that they were preforming l
this inspection step.
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Licensee engineering personnel are investigating various designs
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that will identify grounds at the d.c.
circuit branch level.
One m'etEo'd~th'at~:is being considered by the engineering organ-ization is the TSUDA Model A5000 d.c. Circuit Detection System.
The TSUDA unit has sensors that detect leakage currents as low as 5 milliamperes. A method of installing the TSUDA unit would be to have two branch lines passed through the hole in the sensor body. The output of the sensor, connected to a recording panel, will indicate a short in the branch if one exists.
During this inspection, the inspector witnessed the process of locating grounds using the wire lifting method.
No violations were or deviations were identified.
3.5 Diesel Generator The inspector observed maintenance on Emergency Diesel Generator (EDG) No.12 being conducted per Surveillance Test Procedure number M-20-0, " Diesel Generator Inspection".
The inspector witnessed an examination to determine if a crack in a casting had penetrated the component enti rely.
The crack was examined by both magnetic particle and ultrasonic testing, and was revealed to be a surface imperfection of minimal concern.
Replacement of cylinder liners was also observed by the inspector.
This operation proceeded smoothly as the mechanics demonstrated familiarity with the job.
QC personnel were present and were recording progress of the work, as well as administratively controlling replacement parts on the job site. The inspector learned that QC coverage was in effect for all shifts and found the QC technician present to be knowledgeable and thorough.
No violations or deviations were identified.
3.6 Valve Repacking Program l
The inspector observed valve repacking maintenance that is currently underway at Unit 1.
The licensee has contracted the Chesterton Manufacturing Company to supply graphite packing material. The company is also providing service representative guidance during the repacking of approximately 600 safety and non-safety related valves i
at Unit 1.
I Work is controlled through the use of Maintenance Orders (M.O.), and procedure Pack-1, Rev 2,
" General Valve Packing Procedure".
Each valve to be repacked has its own M.0. that contains a description of work, appropriate approval signatures, description of parts needed, summary of the completed work, QC approval sign offs, and an Opera-tion Text Document that would be forwarded to operations to be used to specify and track retesting of the valves.
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The inspector reviewed approximately thirty completed M.O.'s to verify proper documentation of the work, including:
s Approval signature of the maintenance group supervisor to start
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Work, Size and stock number of packing used,
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Torgue wrench and calibration detector used, and Quality Control review signoff completion.
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The inspector observed the. repacking of valve 20-1-022 and found the mechanic to be very knowledgeable and thorough throughout the entire course of the work. Procedure Pack-1 was followed and the necessary documentation was completed adequately.
No violations or deviations were identified.
3.7 Main Steam Isolation Valve Modification 3.7.1 Modification Scope The licensee performed a major modification of the two main steam isolation valves. These valves were manufactured by Rockwell International with actuators supplied by Greer Hydraulics.
They have previously experienced failures which have affected plant operations and required excessive maintenance. Most of the problems with valve operability have been caused by the valve operators.
Due to this and the fact that parts and technical support are no longer available from the vendor, Greer Hydraulics, the licensee decided to replace the existing MSIV greer actuation system and solid disk globe valve internals with Rockwell Inter-national A-180 gas-hydraulic actuators and balanced - disk globe valve internals. Changing the valve internals from a pure stop valve to a balanced disk globe valve reduces the force required to shut the MSIV under reverse flow conditions by over 90%.
This allows the use of a much smaller actuation system.
The balanced disk design contains a small check-disk assembly in the center of the
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main valve disk which equalizes the steam pressure above l
and below the disk.
During normal operation, the air-l driven pump will open the MSIV in 5-10 minutes.
The actuator will close the MSIV in less than five seconds when either manifold operates and in less than three seconds when both manifolds operate.
The scope of the modification includes scrapping of the old hydraulic system and valve internals. The existing valve body inside bore is modified by weld buildup and machining
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to accommodate the piston rings on the new valve disk. New i
valve parts include:
the disk, check valve, valve stem
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assembly; a new valve bonnet and packing; and the new hydraulic actuator.
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-10 3.7.2 Document Reviews Th[ inspector discussed the procedural controls with the
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responsible engineer who maintains project responsibility for this modification. These discussions and review of the
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documentation indicated that the modification was being performed in accordance with the licensees administrative requirements.
The master copy of modification package 85-1048-M1-1 was maintained up to date; prerequisites were signed off; and in process sign-offs were up to date. The i
welders were trained and qualified. The welding procedure, supplied by the vendor, had been reviewed and approved by the licensee. The new parts had been receipt inspected and tagged.
Special (Radiation) work Work Permits were issued.
Appropriate clean area requirements had been established, which included steam line plugs being installed to keep foreign objects out of the steam lines during welding and machining operations.
The licensee had performed a safety analysis and 10 CFR 50.59 review which concluded that prior NRC approval for the modification was not required.
The licensee also performed a design verification of the planned modifica-tions.
Licensee personnel including engineers, mechanics,
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and operators, attended a three day training course at the vendors facility concerning the operation and maint9 nance of the new valves.
The inspector reviewed the training outline for an on-site course presented to all five shifts of operations personnel which appeared to provide appropriate training for operations personnel.
The responsible engineer explained the requirements for updating the drawings affected by this modification.
Drawings maintained in the control room, (in this case the system P&ID), were required to be updated within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of the completion of the modification.
Since these p&ID's are stored electronically on (Computer assisted drawing (CAD) system, they can be updated and issued quickly.
Other drawings are required to be updated within 90 days of the completion of construction.
At the time of this inspection, modification work was still underway and would not be completed for several weeks.
3.7.3 Witnessing of Modification Activities
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The inspector witnessed modification work being performed on both MSIV's.
This included milling, honing, and NDE inspection of the valves.
The work was being perfumed in accordance with the procedure.
The procedure sir;n-of f s
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including prerequisites and QC sign-offs were being kept up to date.
The latest copy of the procedure was in use.
Radiifidn ~ Work Permit requirements were being followed.
The micrometers and weld rod ovens had current calibration stickers on them.
Cleanliness plugs were in place to keep the steam lines clean.
A QC inspector witnessed these operations; performed required inspections; and, maintained a shift by shift log to document work progress and resolution of problems.
The responsible engineer maintained control over the modification activities and made frequent visits to to the job site.
No violations or deviations were identified.
3.8 Core Exit Thermocouple Modification 3.8.1 Modification Scope In order to comply with NRC Generic Letter No. 82-28, the licensee installed a
modification. This will provide control room operator with a selectable, redundant, digital display of core-exit tem-peratures.
In addition, all forty-five (45) channels will be recorded on redundant multi point recorders located in the CET cabinet in the elevation 45' computer room. These CET's were identified as a
primary component to be monitored along with other plant parameters, as part of the inadequate core cooling instrumentation system.
The existing core exit thermocouples were expanded and upgraded to a safety related system.
The modifications included the addition of a dual output thermocouple transducer to each of the 45 CET channels.
These thermocouple transducers provide two independent i
isolated analog outputs-one for the safety related CET
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display system and the other for the interface with the non-safety related plant Data Acquisition System.
Except for the containment electrical cable support platform area,
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electrical physical separation is provided through-out the design for the redundant core quadrant temperature system.
The existing cable routine from the East and West Electrical Containment Penetration Rooms to the E1.45'
computer room was upgraded to safety related.
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Due to environmental qualification concerns with upgrading
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the incore instrumentation cable assembly connectors, the containment cable assemblies from the reactor probe to the
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electrical penetrations were replaced with qualified
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In addition, the CET circuit portion of the multi-conductor cable assembly was re-routed from the (
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existing penetration to a qualified electrical penetration.
Since,. redundancy is required for each reactor core quadrant monitoring channel, selected channels of one reactor head quadrant (approximately five or six per quadrant) were rerouted from the probe assembly to the opposite quadrant interface panel. In addition, CET system cable trays were upgraded as necessary to meet class IE requirements.
3.8.2 Document Reviews The inspector reviewed the documentation associated with the CET modification 83-1057 E.4-I.
The control work package was being maintained up to date with prerequisites, procedure steps, and QC verifications being signed off where required.
The cable pull sheets were also signed off.
Review of the icensee safety analysis indicated that this modification lodressed the concerns identified in NRC Generic Letter No.
82-28, Inadequate Core Cooling Instrumentation System.
To notify other plant organizations that this modification had been completed the responsible engineer issued an information statement on October 13, 1986.
This information statement included a
list of applicable drawings and a description of the modification.
The statement is the mechanism by which operations, training, technical services, health physics, chemistry and maint-enance are informed of the modification; are requested to make any required changes to their departments procedures or programs, and provide necessary training.
3.8.3 Inspection of Installed Equipment The inspector examined the installed 1C182 CET cabinet in
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the elevation 45' computer room.
This cabinet is the termination point for the thermocouple leads from both the A and B channels.
These channels are separated by a steel fire barrier. The cabinet also houses the transducers and the multipoint chart recorders. The inspector examined the electrical terminations in the cabinet and verified that all connections were tight; adequate strain relief was l
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plugs were installed correctly.
The inspector also
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verified the correct thermocouple wire had been terminated i
on the correct terminal block connector location. This was l
done for a sample of 44 connections in the
"B" side.of the cabinet and 46 connections in the "A" side of the cabinet.
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The verification was performed by comparing the cable mark _1ng with drawings 61-101-C Sheet 1828, Rev. B and Sheet 182A, Rev. B.
All terminations had been correctly made.
The inspector also selected a sample of three cable tray supports which were added to upgrade the cable runs. These cable trays were located in the auxiliary building, elevation 27'
Examination of these supports verified they
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had been installed in accordance with the drawing 83-1057-C-1.
No violations or deviations were identified.
4.0 Unresolved Items Unresolved items are matters about which more information is required in order to ascertain whether they are acceptable items, or violations. An unresolved item identified during this inspection is discussed in paragraph 3.2.2.1.
5.0 Exit Meeting The inspectors met with licensee representatives (denoted in paragraph 1)
at the conclusion of the inspection on November 21, 1986. The inspectors summarized the scope and findings of the inspection as described in this report.
At no time during the inspection was written material provided to the licensee by the inspectors.
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APPENDIX 1
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' DOCUMENTS REVIEWED
. Field Test Procedures (FTP'3)
FTP No. 101, Revision 3, May 8, 1985, Alarm /Setpoint Procedure.
- FTP No.102, Revision 6, October 3,1986, Control Valve Solenoid Valve and Position - Indication - Procedure.
_urveillance Test Procedures (STP's)
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- STP No. M-213-2, Revision 8, November 28, 1984, Calibration of Power Range Instrumentation To In-Core Instruments.
- STP No. M-460-0, Revision 2, Seismic Accelerometer Calibration.
- STP No. M-560-0, Revision 4, Seismic Instrumentation Calibration.
- STP No. M-650-2, No. 22 Station Battery Performance Test.
Preventive Maintenance (PM)
- PM No. 2-18-E-R-1, Revision 3, No. 21 Inverter.
- PM No. 2-19-E-2YR-1, Revision 2, No. 21 and 22 Instrument and No. 21 Plant
Air Compressors.
Seismic Reports
- Kinematics Systems Surveillance Report K6308, November 11, 1986.
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