IR 05000327/1993047
| ML20059D986 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 10/22/1993 |
| From: | George Macdonald, Shymlock M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20059D965 | List: |
| References | |
| 50-327-93-47, 50-328-93-47, NUDOCS 9311030057 | |
| Download: ML20059D986 (14) | |
Text
.
n UNITED STATES
-#
- o proy %e,& NUCLEAR REGULATORY COMMISSION REGION 11
',[ - S 101 MARIETTA STREET, N.W., SUITE 2300-5 7p ATLANTA, GEORGIA 30323 0199 o., e
%,
....+
/
Report Nos.: 50-327/93-47 and 50-328/93-47 Licensee: Tennessee Valley Authority 6N 38A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Docket Nos.: 50-327 and 50-328 License Nos.: DPR-77 and DPR-79 r
Facility Name: Sequoyah Units 1 and 2 Inspection Conducted: September 16 - 24, 1993 Inspector: 4 k /0 M G. MacDonald Date Signed Approved by: MA ff FI. B. Shymlock, Chief
'
"
d7 ./M y
Y22/9J
'Date~ Signed Plant System Section Engineering Branch Division of Reactor Safety SUWiARY Scope:
This special announced inspection was performed to address several emergent electrical Problem Evaluation Reports (PERs) for plant restart. Additional areas reviewed included electrical calculations and drawings, fuse control, and class IE cable manholes and handhole Results:
A non-cited violation was identified for incorrect installation of Weed temperature elements. (paragraph 2)
The licensee's inspection and evaluation of polyvinylchloride (PVC) jackete cables exuding plasticizer was acceptable. The initial inspection and evaluation was adequate to support plant restart. The plasticizer did not pose a significant safety hazard. Corrective action was not finalize (paragraph 3)
9311030057 931022 PDR ADOCK 05000327 G PDR ,
.
.
Selected licensee electrical calculations were examined regarding use of unverified assumptions. The licensee had a program to address unverified calculation assumptions. The calculations reviewed indicated that the licensee was correctly controlling unverified calculation assumption (paragraph 4)
The licensee's class 1E cable tunnel manhole and handhole surveillance program was reviewed. The licensee surveillance was adequate to prevent cable degradation. (paragraph 5)
The licensee's inspection of 480 V Arrowhart motor' starter auxiliary switches was complete for restart. Twenty six percent of Arrowhart starter auxiliary switches required cleaning and eleven percent required repair or replacemen The material condition of the Arrowhart Motor Control Centers was considered acceptable for restart. (paragraph 6)
PER 930333 revision 2 identified additional fuse drhwing and labelling discrepancies, however the correct fuses were installed. The licensee's method for controlling pull out fuseblocks was acceptable. (paragraph 7)
Inspection Report 50-327,328/93-26 identified a concern on incorrectly connected replacement current transformers (cts). Licensee corrective action was to verify that all replacement cts had been phase checked prior to restart. The phase checks on replacement cts were almost complete. One Unit 2 CT set required phasing and it was scheduled for Unit 2 startup when plant conditions allowed. (paragraph 8)
.
i REPORT DETAILS ' Persons Contacted Licensee Employees
- J. Baumstark, Operations Manager
- L. Bryant, Maintenance Manager
- M. Burzynski, Engineering Manager
~ *D. Clifs, Planning Manager
- Driscoll, Site Quality Manager
- T. Flippo, Site Support Manager ,
- J. Gates, Outage Manager ;
- D. Lundy, Systems Engineering Manager
- K. Meade, Licensing Engineer
- Proffitt, Licensing Engineer
- K. Powers, Plant Manager
- H. Rogers, Technical Support Program Manager
- R. Shell, Licensing Manager
- Skarzinski, Technical Programs and Performance Manager
- J. Symonds, Modifications Manager
, *R. Thompson, Compliance Licensing Manager
- J. Ward, Manager - Engineering and Modifications
- N. Welch, Operations Superintendent other licensee employees contacted during this inspection included engineers, operators, craftsmen, and other plant personne Other Organizations NRC Personnel
- Holland, Senior Resident Inspector !
- J. Munday, Resident Inspector, Region II !
- S. Shaeffer, Resident Inspector l
- Denotes those individuals that attended the exit meetin Acronyms and Abbreviations used throughout this report are listed in the last paragrap . Incorrect Installation of Weed Instrument Company Temperature Elements On September 15, 1993, the licensee engineering group discovered that 24 l Weed Instrument Company temperature elements-(TEs) were not installed 2in accordance with the vendor instruction manual and corresponding l procedure. The 24 TEs were utilized for post accident _ monitoring and were required to be environmentally qualified. The vendor instructions required the use of certain sealants and coatings. Review of the DCN package and work plans indicated that the required sealants were not installed. The licensee generated PER SQPER930534 to track problem resolutio I i
'
- . ,. . -
.
There were 12 TEs installed per uni Four of the TEs monitored containment. atmospheric temperature, four TEs monitored containment spray heat exchanger A and B inlet and outlet temperature, and four TEs monitored RHR system A and E RHR pump discharge temperature and RHR heat exchanger outlet temperature. All of the TEs were used for post accident monitoring function The 24 TEs were new installations and the licensee engineering group prepared a new EQ binder, SQNEQ-ITE-005, to establish qualificatio The inspector reviewed the EQ binder and verified that the correct.EQ installation requirements were specified in the binder. The DCNs utilized to install the TEs failed to include the sealing requirements outlined in the EQ binder. The inspector reviewed several of the DCNs j and verified that the sealing requirements were not specifie '
The licensee performed an extent of condition review of the problem as part of the corrective action for the PE There were 10 instances from 1986 to present where a new EQ binder was prepared for a new component installation. The licensee reviewed all 10 DCNs and the EQ binders and did not find other cases where the EQ installation requirements were not included in the DCN. The inspector reviewed DCN L-7113 and verified that the installation requirements were incorporated into the DC The EQ binder required the use of an environmentally qualified conduit seal at the TE terminal housing or the use of a conformal coating spray on the terminal block, wire, and lugs within the TE head. The 8 TEs located inside containment had qualified conduit seals. The 16 TEs used for RHR and containment spray monitoring did not hava a qualified conduit seal and were not sealed with the conformal coating as require All 24 TEs were required to utilize a silicone sealant'on the TE terminal cap gasket and terminal cap threads. None of the 24 TEs had been installed with the required sealant. Work request C222162 for unit 2 containment atmosphere TEs, C222164 for unit 2 containment spray TEs, and C222166 for unit 2 RHR TEs were initiated to seal the devices per the requirements in the EQ binder. The licensee revised the maintenance instruction for installation of the TEs, 0-MI-IEQ-000-020.0 revision 1, EQ Maintenance for 10CFR50.49 Equipment Weed Instrument Company. The inspector reviewed WR C222162 and the revised maintenance instruction and concluded that the correct requirements for sealing the TEs were included.
'
The licensee's failure to properly incorporate the EQ sealing requirements for the installation of the 24 TEs represented a violation of NRC requirements. The incorrect installation was an example of inadequate design control and violated the requirements of 10CFR50 i Appendix B, Criterion III, Design Control. This violation was not . cited because the licensee's efforts to identify and correct the violation met the criteria of Section VII.B of the NRC Enforcement Polic The violation was licensee identified and the licensee initiated a PER documenting the problem. The PER was classified as a restart PE The licensee performed an extent of condition review and found that the
-
?
issue was an isolated problem. Work requests were prepared to seal the 24 TEs and the work was scheduled as a restart activity. The inspector concluded that the licensee's actions were timely and would ensure that
-
the TE installation met the requirements of the EQ binder. Polyvinylchloride Cables Er.uding Plasticizer Inspection Report 50-327,328/93-35 opened IFI 50-327,328/93-35-01 "PVC-Cables Exuding Plasticizer". The licensee was tracking this problem as SQPER931556. The inspector reviewed the licensee's evaluation of the PER to determine if the exuding PVC cables presented a significant safety hazard.
3.1 SQPER931556 The licensee discovered PVC cables exuding an. oily substance on non-safety related cables in the Turbine Building. The substance was determined to be coming from the cable jacket. On June 16, 1993, the licensee initiated PER SQPER931556 and it was classified as.' a non-restart PER. Exuding PVC safety related cables were later discovered in the EDG auxiliary MCCs and the PER was classified as restart. The plasticizer was noted as exuding from both the inner and outer surfaces of the cable jacke The licensee tested the affected circuits in the EDG auxiliary MCCs and -l verified the operability of the cables and the circuit breakers, i Samples of the plasticizer and affected cables were sent to an independent laboratory for testing and analysis. The licensee developed a plan to assess the extent of condition. A procedure was written to control the sample selection, field inspection and evaluation of !
results. The licensee concluded that the exuding PVC cables did not l impact Sequoyah restar The inspector reviewed the licensee's sampling, evaluation procedure, and inspection results. Selected PVC cabling and adjacent plant equipment was inspected. The inspector concluded that the licensee's evaluation was thorough and that the exuding PVC cables did not create a significant safety hazard.
3.2 Testing of EDG Auxiliary MCC Cables and Circuit Breakers l
!
The safety related cables in 480 V EDG Auxiliary Boards lAl-A and 1A2-A exuded plasticizer onto the non-automatic feeder circuit breakers j connected to these feeder cables. The licensee prepared work order 93- !
04800-00 (WR C223613) on EDG Auxiliary Board 1A2-A and work order 93- l 04797-00 (WR C223612) on EDG Auxiliary Board 1Al-A-to megger test the cables and to perform a millivolt drop test on the circuit breaker The inspector reviewed the two work orders and determined that the megger testing was done on both the normal and alternate feeder breaker / cables. The megger testing was done each phase to ground utilizing ikV DC for 5 minute The lowest megger reading was 26
, _ __ -- _ . _ _ _ _ _
-
.- . - - . , - _ _ _
'
,
- ;
megohms which met the test acceptance criteria of a 1 megohm. The inspector concluded that the megger testing verified that the cable insulation was not degraded by the plasticize The EDG Auxiliary Board circuit breaker millivolt drop tests were performed at 100 amps and the highest millivolt drop was 41 millivolt This indicated that the plasticizer did not cause the breaker contacts to fail. The test also demonstrated that the plasticizer had insulating ,
properties and did not provide a ground or short circuit path. The testing demonstrated that the cables and circuit breakers were still operabl .3 Laboratory Testing and Analysis of Plasticizer and Cables The licensee sent samples of the exuding substance and pieces of the cables to an independent laboratory for testing and analysis. The t laboratory performed chemical analysis to identify the material and to assess the consequences of the material on the operability of the cables and adjacent equipment. The inspector reviewed Technical Report 93444 and Appendix, revision 0, " Chemical Analysis and Consequence Evaluation of Exuding Cable Liquid". The laboratory performed infrared spectroscopic analysis and elemental ash analysis and identified the exuding material as adipic acid diethyl ester. Adipic acid diethyl i ester was a recognized cable jacket plasticizer added to the cable jacket during cable manufactur l
The inspector examined the infrared spectra for the samples and noted !
that they very closely matched the standard reference spectrum for the adipic acid diethyl ester. The laboratory verified that the material was non-corrosive to metals and was electrically non-conductive. The ;
samples showed a resistivity of a 10 megohms per centimeter. The ,
laboratory evaluated the cable samples and found no evidence of thermal damage or corrosion and determined that the cable jacket was in goo condition. The plasticizer is added to the PVC to increase flexibilit Loss of the plasticizer would cause the cable jackets to lose flexibility and become brittl The report concluded that an inspection and evaluation of equipment '
located adjacent to the exuding cables should be performed. .The laboratory report indicated that the plasticizer could cause softening and/or swelling of certain polymers, particularly ethylene-propylene ;
rubber, hypalon, and ethylene vinyl acetate. Additionally, the plasticizer could drip on and insulate normally open contacts and affect ,
operation of plant equipment. - The ' inspector verified that the cables at l Sequoyah which utilized PVC jackets had polyethylene insulation which was not degraded by the plasticizer material. The plasticizer did not degrade the insulating properties of the cable . . . . . - .
. -
.
3.4 Licensee Evaluation of SQPER931556 SQPER931556 was classified as a restart PER. The planned corrective action was to address the impact of the plasticizer on plant equipment considering all cables having PVC jacket material. The licensee developed procedure, SQPER931556 Evaluation, revision 1, to determine the extent of condition and the effects on surrounding devices of PVC plasticizer exuding from PVC jacketed cables. The instruction provided details on the grouping of end devices, performing engineering evaluations on the end device groups, performing field walkdowns on group samples, and evaluating the result In order to evaluate the impact of the PVC plasticizer, the licensee developed a listing of plant equipment end devices which utilized PVC jacketed cables. The licensee utilized construction cable data and the cable routing database to generate the listing. The listing formed the basis of the evaluation and contained approximately 18,500 PVC jacketed cable The inspector reviewed the TVA corporate cable type specifications and determined that 6 cable codes utilized PVC cable jackets. The SOPER931556 evaluation instruction addressed 4 of the 6 cable codes with PVC jackets. Cable codes PJ and CPMJ which had PVC cable jackets were not included in the evaluation. The licensee provided a computer run which showed that only one cable of type PJ and no cables of type CPMJ were in use at Sequoyah. The inspector concluded that the scope of cables evaluated in SQPER931556 was adequat The licensee sorted the cables into 25 different end device groups. The inspector reviewed the marked up listing and verified that all PVC jacketed cables had been included in the end device groupings. The licensee evaluated the groups to determine if the equipment could be adversely affected by the plasticizer. Both TVA Nuclear Engineering site and corporate engineers performed the evaluations. The inspector reviewed the data sheets which documented the evaluations of the device groups. The evaluations determined 5 groups which would not be affected by the plasticizer and would not require field inspection. The inspector concluded that the basis for the evaluations was adequat Field walkdowns on a sample of the remaining 20 device groupings were performed by the licensee to determine if the plasticizer could enter into or degrade the end device. The licensee selected a weighted sample of devices in each grouping for inspection. The criteria for selecting end devices was based on obtaining a sample representing different building locations, different device manufacturers and different cable manufacturers. All the cabling in 251 end devices was inspecte The walkdowns were performed by teams led by TVA NE engineers. The results were documented on data sheets. Summary sheets were prepared for each group and they were signed by both TVA NE and corporate engineers. When the end device was determined to have the potential for being affected by the plasticizer, a component functional evaluation was
_ _ _ .
= _ . , . ;-a A '< - - - -e e-~r J
!
.
complete Eleven of the end devices inspected were determined by the licensee to be potentially affected by the plasticizer due to the cable and device orientatio The licensee performed functional evaluations of these devices and determined that operability of the devices was not affecte The inspector performed walkdowns of the 11 potentially affected devices, all EDG Auxiliary MCCs, selected turbine building MOV and Vent Boards, and selected local control panels. The EDG control cabinets and battery cables were also inspected. The inspector found no cases where the plasticizer had dripped onto equipment except for the case previously identified in the PER (EDG Aux. MCC 1Al-A)
Most end devices did not have significant amount of jacketed cable inside. The jacket was usually removed a short distance after the cable entered the device. The cases where enough plasticizer had collected to form droplets were cases of large diameter cables or bundles of smaller cables in vertical runs over or terminated onto end devices. This was the case for the 2 worst locations, the EDG Aux MCCs and the Heat Trace Control Cabinets. Of these two cases, the EDG Aux MCCs was definitely the worst case. The licensee's testing verified the operability of the affected EDG Auxiliary MCC circuits. The licensee wrote work requests to clean all locations which had been identified as having plasticizer leakage during the SQPER931556 inspections. The 2 cases with the most significant plasticizer accumulations, the EDG Aux. MCCs and the Heat Trace Control Cabinets were cleaned prior to restar The inspector reviewed the licensee's procedure and all evaluations and walkdown data sheets. The licensee procedure was thorough and the evaluations and walkdown results were documented. The inspector '
concluded that the initial assessment provided evidence that the plasticizer did not pose a significant safety hazard and did not impact Sequoyah restar Licensee corrective action for SQPER931556 was not complete. The licensee indicated that they would develop an ongoing monitoring program to continue to assess the potential impact of the plasticizer on plant equipmen Since the final corrective action for the PER was not complete, IFI 50-327,328/93-35-01 remains ope . Unverified Assumptions In Engineering Calculations The inspector reviewed licensee electrical calculations to determine if calculation assumptions were adequately addressed. The licensee had an ongoing program to document and correct unverified assumptions in calculations. The licensee Electrical Engineering Group identified 60 calculations with unverified assumptions. The licensee was revising calculations to document and remove the unverified assumptions. At the time of this inspection,13 of the 60 calculations with unverified assumptions had not been revised. All the calculations were scheduled to be revised prior to restar .,_ _
.
Problem Evaluation Report SQNEEB8654 was reviewe The PER indicated that cable length values obtained from the computer cable program should not be used for design work. For corrective action, Electrical Engineering Branch issued Policy Memorandum PM 87-26, Cable Length Values To Be Used In Electrical Calculations. PM 87-26 directed that construction cable pull length should be used for voltage drop calculations. PM 87-26 required that short circuit calculations should :
initially be performed with no cable impedance to calculate the maximum fault current. If the maximum fault current exceeded equipment capabilities then the minimum cable length to limit fault current to equipment ratings should be determined. The installed cable length should then be verified to be greater than the minimu The inspector reviewed several calculations to determine if actual or design values of cable lengths were being used in calculations. For the-calculations reviewed, the inspector determined that the calculation determined the maximum allowable cable length or used construction pull lengths. Design values of cable lengths used in calculations were treated as unverified assumptions. The inspector concluded that cable i length values were being correctly used in licensee calculation Sequoyah Audit No. SQA91107 identified a case where Modifications Group installed cables with lengths 2: the lengths specified in DCN M01435 (Unit 1) and M01436 (Unit 2) without notifying Nuclear Engineering (NE). ,
PER SQA910288 was issued by NE to resolve this deficienc The l inspector reviewed PER SQA910288. The PER was still ope The maximum l cable lengths had been specified in the DCN in the electrical requirements section. The maximum allowable cable lengths should have l been specified in the special requirements section. The calculation of the cable lengths was performed by a contractor. As part of the i corrective actions for the PER, the licensee reviewed 5 additional l contractor calculations and noted no operability problems. Calculation l weaknesses were noted in not fully documenting assumptions and not j referencing values used in the analysi PER SQA910288 was reviewed and classified as non-restart. The cables installed in DCN 1435 (Unit 1) and DCN 1436 (Unit 2) served radiation monitors 1/2-RE-90-400 used for offsite dose calculation and for post accident monitoring. The radiation monitors voltage might not be adequate during an undervoltage condition. Radiation monitor failure was alarmed in the main control room. Manual monitoring capability would be utilized if the radiation monitors failed. Modifications DCNs M09083A (Unit 1) and M09084A (Unit 2) were scheduled for Unit I cycle 7 l and Unit 2 cycle 6 outages respectively to address-the undervoltage concern for the radiation monitors. Licensee Engineering Evaluation Justification for Continued Operation (JCO) No. SQJC0-92-004 discussed the radiation monitor operation and the compensatory actions for loss of the monitors. The inspector reviewed the JC0 and determined that the evaluation and compensatory measures were acceptabl l l
)
8 The inspector reviewed CAQR SQP880144 on ERCW MCC load The CAQR addressed a failure to evaluate non-safety related load breaker selective coordination and auto-ignition damage and a failure to properly identify loads as non-safety related on design documents and drawing The inspector reviewed the CAQR and the corrective action. Calculation SQN-APS-003 evaluated coordination of the ERCW MCC breakers. Wiring diagrams were revised to designate non-safety related loads. Exception EX-SQN-DC-V-12.2-6 was issued regarding the routing of non-safety related cables from the ERCW MCCs with class IE cables. The basis for the exception was that the non-safety related loads were fed from the load shedding bus and were shed upon an accident signal. Isolation from class IE loads was provided by circuit breaker Cables for the non-class lE loads were designated and routed as train A and B cable The inspector reviewed single line diagrams and wiring diagrams for the ERCW MCCs lA-A, IB-B, 2A-A, and 28-B and verified that the drawings incorporated proper identification of non-safety related loads. The drawing showed that the non-class IE cables were train designated and ;
referenced the design criteria exception. The drawings showed the load shedding breakers and the inspector verified that all the non-safety related loads were from the load shed bus.
5. Submerged Cables in Class IE Manholes And Handholes The inspector reviewed CAQR SQP900508 on lack of preventive maintenance and inadequate PM tracking on class IE manholes and handholes. The CAQR also identified a concern regarding the design of the manholes and handholes for tornado depressurizatio The licensee determined that the ERCW manholes and handholes were adequately designed for tornado depressurization. Handhole 29 was the on;y class IE handhole or manhole not evaluated. SQP900508 evaluated the design of handhole 29 and concluded that the cover and structure would adequately withstand the tornado forces. The inspector determined that the SQP900508 evaluation was acceptabl CAQR SQP900508 indicated that many class 1E cable manhole and handhole sump pump systems were inoperable and allowed frequent floodin Failure to perform required PM and inadequate tracking of PMs was cited as the reason for the condition. The licensee modified PM tracking such that PMs were listed as delinquent when they passed their performance date. Additionally, the PM program was changed to require Technical Support System Engineer concurrence to defer a PM. The inspector reviewed PM tracking and verified that the above changes had been implemente The licensee repaired all sump pump systems for the class IE manholes and handholes. This included cleaning and repair to sump pumps, power supplies, controls, and piping. Many sump pumps were replaced and all 480 V and 6900 V cables were tested. All 480 V splices were replace _ _ - _
.
Nuclear Engineering inspected and evaluated cables in flooded manholes and handholes and concluded that the water exposure had not degraded the cables. Grading around the manholes and handholes was modified and some curbs were added to improve yard drainage around the manholes and handholes. To prevent recurrence, the licensee modified the manholes and handholes to allow measurement of level with a dipstick. A monthly manhole and handhole dipstick level monitoring PH was institute The inspector reviewed the manhole and handhole PM procedure and found that it was thorough and incorporated a requirement to generate PMs to investigate any evidence of water accumulation. The procedure addressed the transformer vaults and included a notification to NE and a requirement for an NE evaluation of any cables which had been exposed to water. The procedure addressed the concerns raised in the CAQR. The inspector reviewed a random sample of the PMs performed with the procedure and noted that the procedure was being followed. The results showed that the sump pump systems were preventing flooding conditions, and, in the one instance where an accumulation of water was noted in the sample reviewed, NE had evaluated the affected cables. Repairs were made to the sump systems to return them to operable status. The inspector concluded that the procedure and its implementation would prevent flooding of class lE manholes and handholes and maintain the reliability of the class IE cable The inspector reviewed the data on cable testing and verified that no cables had failed hipot testing. The megger test data was reviewed and it showed no cable degradation. The inspector concluded that the class 1E cables in manholes and handholes were still operable. The corrective actions in CAQR SQP900508 were adequate to control submergence of cables in class lE manholes and handhole . Arrowhart Motor Starter Auxiliary Switches The licensee generated PER SQPER930208 on Arrowhart motor starter auxiliary switches. Failure of a motor operated valve to function was caused by failure of the auxiliary switch on its respective motor ,
'
starte Corrective action required inspection of all Arrowhart motor starter auxiliary switche The licensee inspected 821 Unit 2 and Unit I common starters. Of the switches inspected, 526 passed (63 %), 212 needed cleaning (26%), and 93 .
required repair or replacement (11%). The inspection was complete and l post maintenance testing (PMT) was ongoing. The inspector witnessed J licensee PMTs on Arrowhart motor starters (93-04186-004, 93-05747-00, l 93-05747-09, 93-04183-00, 93-04183-03). The PMTs were acceptable and !
the inspector concluded that corrective action for PERSQP930208 was 1 satisfactor . - . . _ . . - -.
7. Fuse Control PER SQPER930333 revision 2 identified 15 additional fuse deficiencie The Operations group performing fuse labelling identified the 15 item The inspector reviewed the items. The correct fuses were installed in the plant. All fuses were FLASS fuses. The deficiencies concerned differences between plant drawings and EMS (the plant's compt:ter fuse tabulation), fuses without unique identifiers, spare circuit fuses, and incorrectly colored label Changes were made to EMS and plant drawings will be changed to incorporate unique identifiers for fuses which were not labelled. The design for spare circuits called for the fuse to be installed in the fuseblock and the wires lifted downstream of the fuseblock. Fuses will be installed in spare locations and labels marked SPARE will be installed. PER SQPER930333 revision 2 had been classified as a restart PER. The inspector concluded that the licensee had thoroughly evaluated the 15 discrepancies and that these items did not impact Sequoyah restar CAQR SQT870585 concerning marking reversible fuseblocks was reviewe !
The concern was that reversible fuseblocks utilized in 6.9 kV switchgear control circuits could be installed incorrectl If the fuseblock was incorrectly installed, the control circuit would be deenergized and the breaker would not operat The CAQR indicated that paint match marking of the fuseblocks should be utilized to ensure that the fuseblocks are !
properly installed in the on positio ]
The licensee management review group evaluated the CAQR and determined l that it was not a condition adverse to qualit The CAQR was closed and PIR SQNEEB8823 was opened to track concern resolution. The PIR was evaluated and the licensee determined that the fuseblock ON and 0FF marking embossed into the removeable portion of the fuseblock was adequate to ensure proper installation. Additionally, the licensee fuse control program did not allow the reversing procedure to be utilize The fuse control program required that the removable portion of the fuseblock which contained the fuses be placed in a bag or container attached to the outside of the breaker compartmen The inspector walked down the turbine building common boards, unit boards, and selected 6.9 kV shutdown boards a.d found that the fuseblocks were not match marked. The fuseblocks were clearly embossed with ON and 0FF indicators and the inspector concluded that these markings were adequate to ensure proper installation. Additionally, the inspector observed many clearance tagouts in the field and verified that the licensee was properly implementing the requirement to remove, tag, and attach the fuseblock in a bag outside the breaker compartment. The '
inspector interviewed operations personnel responsible for removal and installation of fuses and all personnel were familiar with and understood the embossed markings and knew how to properly install the fuseblocks. The inspector concluded that the licensee was maintaining i control of pull out fuseblocks, and that PIR SQNEEB8823 had been i adequately evaluated.
.. .
..
.
.
11 Incorrectly Installed 6.9 kV Current Transformers Inspection Report 50-327,328/93-26 described a concern regarding incorrect wiring of replacement cts. The licensee conducted an incident investigation of the issue. Corrective action was to verify that all replacement cts were properly wired prior to plant restar At the time of this inspection, 1 Unit 2 and 2 Unit 1 CT sets required phasing to verify correct installation. The Unit 2 CT set which required phasing was the Heater Drain Pump 2B overcurrent relay CT set (WR-C081349). This CT/ relay required that the load be energized for relay phasing and was scheduled during Unit 2 startup when plant conditions allowed. The Unit 1 cts requiring phase checks were Condensate Booster Pump IB overcurrent relays (WR C076937), and Hotwell Pump IC overcurrent relays (WR C081534). The Unit 1 cts requiring phase checks were scheduled prior to Unit I restart (Unit I cycle 6).
The inspector reviewed WO 93-03897-00 (WR C081297) for performance of CT/ relay phasing checks on Condenser Circulating Water Pump 2C. The inspector concluded that the work package adequately documented the CT checks and that the replacement CT was correctly installe . Exit Interview The inspection scope and results were summarized on September 24, 1993, with those persons indicated in paragraph I. The inspector described the areas inspected and discussed in detail the inspection finding Dissenting comments were not received from the licensee. Proprietary information is not contained in this repor . Acronyms and Abbreviations CAQR Condition Adverse to Quality Report CT Current Transformer DCN Design Change Notice EDG Emergency Diesel Generator EQ Environmental Qualification ERCW Emergency Raw Cooling Water IFI Inspector Followup Item JC0 Justification for Continued Operation kV Kilovolt MCC Motor Control Center NE Nuclear Engineering PER Problem Evaluation Report PIR Problem-Identification Report PMT Post Maintenance Testing PWC Plastic Wire Corporation-PVC Polyvinylchloride
_
-
.
RHR Residual Heat Removal l SQPER Sequoyah Problem Evaluation Report i TE Temperature Element 'l TVA Tennessee Valley Authority V Volts Alternating Current VDC Volts Direct Current WO Work Order ;
WR Work Request
'
t ' [i
.
F ,i
'
o u
)
l l
I l
. . _ . __, . .