ML20239A082
| ML20239A082 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 08/27/1987 |
| From: | Croley B, Humenansky D, Marshall T SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| To: | |
| Shared Package | |
| ML20238F564 | List: |
| References | |
| NUDOCS 8709170067 | |
| Download: ML20239A082 (22) | |
Text
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EXPANDED AUGHENTED SYSTEM REVIEH AND TEST PROGRAM (EXPANDED ASRTP)
EVALUATION
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0F THE 120 VOLT AC VITAL POWER SYSTEM SYSTEM 4?ttk') 2f M2e21/ I DATE: -[-2N
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SUBMITTEDBY:l e
THOMAS N. MARSHALI.
TEAM LEADER CONCURRENCE:
13M A 3M c DATE: lb4 2L.Nf7
[DAVIDHUMENANSKY j/
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EXPANDED ASRTP PROGRAM MANAGER k 7/77 CONCURRENCE:
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DATE:
BOB CROLEY
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DIRECTOR, NUCLEAR TECHNICAL SERVICES j 8709170067 870909 i
PDR ADOCK 05000312 G
TABLE OF CONTENTS Pace Number 1.0 It!TRODUCTION 3
2.0 PURPOSE 4
3.0 SCOPE 5
4.0 OVERALL RESULTS AND CONCLUSIONS 6
5.0 SPECIFIC CONCERNS 7
5.1 Acknowledged (Valid) Concerns 5.2 Open (Potential) Corcerns 6.0 ATTACHMENTS 6.1 List of Documents Reviewed 10 6.2 Status of RIs 12 6.3 Detailed Observations - Requests for Information 13 i
EXPANDED AUGHENTED SYSTEM REVIEW AND TEST PROGRAM EVALUATION OF THE 120 VOLT AC VITAL POWER SYSTEM 1
1.0 INTRODUCTION
l The Rancho Seco Expanded Augmented System Review and Test Program
[ASRTP] evaluation effort involves an assessment of the effectiveness of the System keview and Test Program [SRTP) and an analysis of the adequacy of ongoing programs to ensure that systems l
will continue to function properly af ter restart._ The Expanded ASRTP is a detailed system by system review of the SRTP as implemented on 33 selected systems and'an in-depth review of the I
engineering, modification, maintenance, operations, surveillance, inservice testing, and quality programs.
It~also conducts a review, on a sampling basis,-of many of the numerous ongoing verification and review programs at Rancho Seco.
Six multi-disciplined teams composed of knowledgeable and experienced personnel are tasked with performing'the Expanded ASRTP.
Each multi-disciplined team consists of dedicated personnel I
with appropriate backgrounds to evaluate the operations, maintenance, engineering, and design functional areas.
Independence, perspective, and industry standards provided by team members with consultants, architect engineer and vendor backgrounds are joined with the specific plant knowledge of SHUD team members.
Each team performs an evaluation on a selected system using the same fundamental evaluation techniques employed by the NRC in the ASRTP l
inspection.
System Status Reports are used as the primary source of leads for the teams.
They'are augmented with references to available source and design bases documents as_needed.
Team synergism and communication is emphasized during the process in order to enhance the evaluation.
Each team prepares a report for each completed selected system evaluated.
This report is for the I
120 Volt AC Vital Power system.
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i 2.0 PURPOSE The objectives of the Expanded ASRTP evaluation are to (1) assess the adequacy of activities and systems in support of restart and (2) evaluate the effectiveness of established orograms for ensuring safety during plant operation after restart.
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1 3.0 iCDPl To accomplish the first objective, the Power Systems team evaluated the 120 Volt AC Vital Power system to determine whether:
1.
The system was capable of performing the safety functions required by its design bases.
2.
Testing was adequate to demonstrate that the system would perform all of the safety functions required.
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System maintenance (with emphasis on pumps and valves) was adequate to ensure system operability under postulated accident conditions.
4.
Operator and maintenance technician training was adequate to ensure proper operations and maintenance of the system.
5.
Human factors relative to the system and the system's supporting procedures were adequate to ensure proper system operations under normal and accident conditions.
To accomplish the second objective, the team reviewed the programs as implemented for the system in the following functional areas:
1.
Systems Design and Change Control 2.
Maintenance 3.
Operations and Training 4.
Surveillance and Inservice Testing 5.
Quality Assurance 6.
Engineering Programs The team reviewed a number of documents in preparation for and 1
during the Expanded ASRTP evaluation.
This list of documents is i
found in Attachment 6.1.
The primary source of leads for the team were the problems identified in the 120 Volt AC Vital Power System Status Report.
Various source documents such as the USAR and Technical Specifications and available design bases documents were reviewed as needed to augment the information needed by the team.
The evaluation of the 120 Volt AC Vital Power system included a review of pertinent portions of support systems that must be functional in order for the 120 Volt AC Vital Power system to meet its design objectives.
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4.0 OVERALL RESULTS AND CONCLUSIONS I
The more significant issues identified pertaining to the adequacy of the SRTP and the effectiveness of programs to ensure continued safe operations after restart are_ summarized below.
The summary focuses on the weaknesses identified during the evaluation. Attachment 6.3 provides detailed findings by providing the Request for Information j
(RI) forms that are used by the Expanded ASRTP teams to identify I
potential concerns during the evaluation.
Section 5.0 lists the 1
specific concerns identified by the teams.
The numbers in brackets j
l after each individual summary or concern refer to the corresponding RIs in Attachment 6.3.
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l 4.1 Equipment designated as "reguired for safe shutdown" may be taken 4
out of service by failure of the 120 Volt AC Vital Inverters because
-l they may not be properly qualified.
i Four Elgar inverters were installed in the 120 Volt AC Vital Power
'I System in 1983 by ECN A-3660. A problem was identified with dirt buildup inside the inverters.
To resolv_e this problem, the bottom i
located air intakes were blocked and new openings were made in the j
front of the seismically qualified panel.
Filters were installed to prevent dust from entering.
This was apparently done under a Work l
Request without Nuclear Engineering input.
This modifies the air flow path from what is specified in the vendor manual.
The above actions have created the following concerns:
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The air flow volume may not be sufficient to ensure adequate cooling.
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The air flow path may not be adequate to ensure cooling of I
the transformer windings in the bottom of the inverters.
3.
A seismic analysis has not been performed to ensure the l
modification has not invalidated the seismic qualification i
of the inverters.
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The inverters were environmentally qualified by the vendor, but, the change in ventilation may have invalidated the environmental qualification.
Problems identified in Audit Report 0-474 were deemed significant l
enough to remove Elgar from the Approved Suppliers List.
These i
problems were apparently not resolved prior to receipt of the inverters.
The vendor manual specifies several components which j
must be replaced at specific intervals to maintain qualification of the inverters.
Procedures have not been implemented to perform this l
required replacement at the required intervals.
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OVERALL RESULTS AND CONCLUSIONS (Continued) 4.2 Due tol inadequacies in the alarm and annunciation design, degradation of the 120 Volt AC Vital Power System may go undetected.
The bus undervoltage alarms are designed to detect loss of voltage but not degraded voltage.
The other annunciation in the Control Room is an inverter-common trouble alarm.
This alarm has l
eight inputs from the inverter local alarm panel with automatic reset function.
The undervoltage alarm setpoint was determined.,
from the vendor manual, to be 108 volts. This is approximately 9 volts below the designed minimum voltage to ensure operation of equipment feeding from the bus.
Due to the alarm setpoints, operation of buses at voltages as low as 108 volts is possible without any alarm.
Degraded output voltage from inverters and regulating transformers is a reasonable failure mode because of degradation of internal components such as capacitors and silicon controlled rectifiers.
The static transfer switch should transfer at 117 volts but, if this does not occur, no alarm will be generated.
None of the local alarm setpoints have been specified.on any Nuclear Engineering generated document.
The transfer of the static switch is a Limiting Condition for Operation.
The operator-will not know this condition exists until someone can check the local alarms and determine which condition initiated the common trouble alarm.
If the static switch transfers back before their arrival all alarms will be cleared and the cause of the alarm cannct be determined.
Intermittent trouble or system transients will be very hard to identify.
The design of the alarm functions and setpoints are not adequate to allow the operator to properly assess the condition of the system. l w-
5.0 SPECIFIC CONCERNS A list of the specific concerns the Expanded ASRTP team believes are new concerns not previously identified for re:olution follows:
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5.1 Acknowledged (Valid) Concerns
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1 5.1.1 The 120 Volt AC Vital Inverters may not be seismically or environmentally qualified as required.
[RI 146] [RI 149]
5.1.2 Alarm logic, annunciation and setpoints may not be adequate l
for the operator to properly assess the status of the system.
[RI 138]
5.1.3 Operators do not receive adequate training and guidance on a
the plant inverters.
[RI 133]
j 5.1.4 Plant procedures which place the plant in a Limiting Condition of Operation do not reference the Limiting Condition or the Technical Specification involved.
[RI 144]
5.1.5 Examples were found indicating the USAR was not updated with
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facility changes made by ECNs.
[RI 143]
5.2 Open (Potential) Concerns 5.2.1 None i
6.0 ATTACHMENTS 6.1 List of Documents Reviewed 6.2 Status of RIs 6.3 Detailed Observations - Requests for Information
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LIST OF DOCUMENTS REVIEWED l
USAR Section 8 System Status Report for VBS, Rev. 1 Rancho Seco Technical Specifications Draft Copy of System Design Bases, DB 5482 l
Quality Control Instruction QCI-12, Rev. 3 Master ECN List Vendor Instruction Manual E8.02.1-ll Rancho Seco Audit Report 0-778, 02-07-86 Rancho Seco Audit Report 87-003, 06-18-87 All NCRs generated against ECN R-0955 Abnormal Tag Report 4424 Nonconformance Report 4723
.ECN A-5710, Rev. 1 Qualified Suppliers List Certificate of Conformance for P.O. R0-87-03-11062 Construction Specification NEPH 5304.8C Construction Methods and Procedures Manual ECN A-3660 Vendor Manual E8.03.1-24 Purchase Specification for Elgar Inverters Nuclear Plant Reliability Data System Printout for Inverters Rancho Seco Generating Station, Systems Training Manual Training Preparation Guide 00-23-J-2400 Training Preparation Guide 00-21-I-6300 120 Volt AC Modifications OD-24-C-0729 Plant Maintenance Daily Work Listing 10CFR50.72 Nonemergency events, one hour notifications Technical Specification Amendment 147 Vendor Manual E8.02.1.1-22 Design Criteria 5104.1 Receiving Inspection Data Package (RIDR 3154 Pz) emorandum GVC 87-770 July 6, 1987 Office u NonConformance Reports 6636, 6652, 6588, 6150 and S-054 NRC Information Notice 87-24 Procedures A.62, Rev. 10, 120 Volt AC Vital System, Draft A.62, Rev. 8, 120 Volt AC Vital System C.157, Rev. O, loss of 120 Volt AC Vital Bus $1A C.158, Rev. O, Loss of 120 Volt AC Vital Bus Sl A2 C.159, Rev. O, Loss of 120 Volt AC Vital Bus SlB C.160, Rev. O, Loss of 120 Volt AC Vital Bus. SIB 2 C.161, Rev. O, Loss of 120 Volt AC Vital Bus SIC C.162, Rev. O, Loss of 120 Veit AC Vital Bus S1C2 C.163, Rev. O, Loss of 120 Volt AC Vital Bus S10 C.164, Rev. O, Loss of 120 Volt AC Vital Bus S102 ATTACHMENT 6.1 I
LIST OF DOCUMENTS REVIEWED i
Procedures (Continued)
IDADS Annunciator Response Procedure, Rev. 3, Draft IDADS Annunciator Response Procedure, Rev. 2 STP.975, 120 VAC Vital Power System Regulating Transformer Functional Test STP.964', 120 VAC Vital Power System A/B/C/D Bus Power Functional Test l
AP.82, Rev. O, Conduct of Special Testing AP.2 27, Rev. O, Special Test Procedures Format and Content AP.81, Rev. O, Qualification and Certification of System Review and Test Personnel AP.65, Rev. O. Routine Test Program
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AP.23.15, Rev. O, Equipment Labeling AP.23.08, Rev. O, Reporting Notification AP.44, Rev.11, Plant Modifications - ECN Implementation NEP 4109, Rev. 7, Configuration Control (Ref. ECP-1)
EM.171B, Station Inverter Routine - Elgar Inverters Work Reauests 129145 124824 t
1356380 01157020-0 Calculations Z-VBS-E0659, Rev. 2, Breaker Coordination for 120 Volt AC Vital System Z-EDS-E0699, Rev. O, Vital 120 Volt AC System Breaker Coordination Study Z-VBS-E0635, Rev. 1, Ampacity and Voltage"Orop Analysis of Cabling to the i
120 Volt AC Vital Bus Distribution panels.
Z-VBS-E0523, Rev. 2, Load Study for 120 Volt AC Vital Buses.
Drawinas E-108, Sheet 12, Rev. 13 E-108, Sheet 1, Rev. 22 E8.02.1-5-1 C12-63644-5A1 Cl2-63644-6Al E-108 series l
i ATTACHMENT 6.1
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STATUS OF RIs.2 provides RI status as of tnis eport date. An RI is l
considered closed if the Team Leader was co' r cid a potential concern I
was not valid or not significant enough to be an RI. An RI would also be closed if requested information was provided.
All other RIs are open.
Acknowledged RIs are open RIs that have been accepted as valid by the responsible organization and have been stated as concerns in Section 5.0.
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.RI NUMBER STATUS 1
133 Acknowledged l
138 Acknowledged
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143 Acknowledged l
144 Ack?,cwl edged 145 Closed 146 Acknowledged 149 AcLijwlJdged i
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i ATTAC;-NENT 6.2 1 J
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DETAILED OBSERVATIONS - REQUEST FOR INFORMATION During an evaluation, all potential concerns are documented on Request for Information sheets (RIs) that are sent to the responsible organization to receive their input concerning the potential concern.
RIs are also used to request information that the EASRTP team is having difficulty obtaining.
These RIs are considered drafts throughout the entire evaluation until they become part of the report.
Responsible organizations can accept the potential concern as valid or they may disagree with the potential l
concern.
If they disagree, they can submit information that convinces the EASRTP team members that the potential concern is not valid, or they may redirect the EASRTP members to better focus the concern.
RIs developed during the system evaluation comprise this section of the report.
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ATTACHMENT 6.3 l _ _ __ _ _ _ _ _-__
REQUEST FOR INFORMATION (RI)
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RI NO:
133 SYSTEM C00E:
VBS ISSUE DATE:
08-13-87
SUBJECT:
OPERATOR TRAINING ON 120 VAC INVERTERS IS INADE00 ATE DEPARTMENT:
TRAINING COORDINATOR:
P. TURNER /4647 TEAM LEADER:
T. HARSHALL/3965 l
POTENTIAL CONCERN /0VESTION:
Operators do not receive adequate training and guidance on plant inverters which may lead to:
1.
Improper operation of inverters 2.
Equipment damage 3.
Loss of 120 Volt AC Vital Buses 4.
Inadvertent plant trips 5.
Inadvertent safety features actuation 6.
Operators not being aware of LCO conditions.
Alarm lights, synchronized lights,and control functions are not covered by training or procedures.
Inverters SIA2, S182, SIC 2 and S102, installed in 1983, are not addressed in licensed or non-licensed operator training lectures.
Inverters SlA2, S1B2, SIC 2 and SID2, installed in 1983, are not addressed in operator training manuals.
Operators are not aware of procedures for energizing and de-energizing new-inverters.
An operator was observed de-energizing S102 inverter, when asked about the procedure he was unaware of it.
Some inverter alarms indicate LCO conditions which the operator may
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not be aware of due to inadequate training and procedures.
ATTACHMENT 6.3 i
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i REQUEST FOR INFORMATION (RI)
RI NO:
138 SYSTEM CODE:
VBS ISSUE DATE:
08-14-87 1
SUBJECT:
120 VOLT AC VITAL POWER SYSTEM 1-DEPARTMENT:
ENGINEERING COORDINATOR:
R. LAWRENCE /4365 l
TEAM LEADER:
T. MARSHALL /3965 POTENTIAL CONCERN /00ESTION:
The alarm logic, annunciation and setpoints for the 120 Volt AC Vital Power System may not be adequate to allow the operator to properly assess the condition of the system and the impact to the plant.
i The possibility exists for portions of the 120 Volt AC Vital Power system to be in a degraded condition; i.e. not able to function, without the operator's knowledge.
Electrical System Design Criteria NEFM 5104.1, specifies that a minimum bus voltage r,f 116.8 must be maintained to ensure operation of end devices.
The alarm setpoint for the vital buses in the NSEB is approximately 65 volts.
The alarm setpoint for the vital buses in the Auxiliary Building is approximately 106 volts.
The alarm setpoint for the Vital Inverters is approximately 108 volts as determined by maintenance technicians.
The Static Transfer Switch should transfer at 117.5 voits, however, if the transfer fails to occur there will be no alarm and operation could continue for an extended period at voltages as' low as 108 volts with no alarms and without the operator's knowledge.
The inverter low voltage and high voltage alarm setpoints do not
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appear to have been addressed by Nuclear Engineering in any design J
document.
The electrical technicians set the alarms per the vendor manual which is generic for the equipment but does.not address requirements at Rancho Seco.
No true frequency alar.n exists.
The "Out of Synt" alarm will alarm for other conditions and would be sealed-in if the alternate supply is unavailable.
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l RI 133 (Continued)
.The DBR for ECN R-0955 states that failure of the static switch is alarmed.
This does not. appear to be true.
The operation of RPS, EFIC, Rad Monitoring, HVAC and other vital equipment cannot be assured outside design limits of voltage and frequency at the bus.
I Operations of Static transfer switches H8TA3, H8TB3, H8TC3, and I
H8TD3 may cause entry and exit of Technical Specification 3.7.?
'.s of Amendment 147, without operator knowledge.
The static transfer switch transfers to the alternate supply on inverter fault, overload, or low voltage and will transfer back to the inverter as soon as the condition clears.
t An alarm is received on the IDADS computer when the " transfer switch
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not on. normal source" alarm is received on the inverter alarm panel, j
but when the transfer switch transfers back to the inverter, the inverter alarm clears automatically.
Static switch transfers due to inverter glitches or voltage dips may result in many LC0 conditions before the actual problem is discovered.
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l ATTACHMENT 6.3 !
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REQUEST FOR INFORMATION (RI)
RI N0:
143 SYSTEM CODE:
VBS ISSUE DATE:
08-17-87
SUBJECT:
USAR UPDATE DEPARTMENT:
NUCLEAR LICENSING COORDINATOR:
J. DELEZINSKI/3909__
TEAM LEADER:
T. MARSHALL /3965 POTENTIAL CONCERN /0UESTION:
Several examples were found indicating the USAR was not updated with facility changes made by ECNs.
The USAR is a bases for licensing, training, procedures and safety analyses.
120 VAC Vital Power system was modified as an extension of the electrical distribution system.
ECNS A-3660N, A-3660P, A-3660T and A-3660U which added four 25 KVA inverters and 120 VAC Vital Buses were closed on 07-27-83.
USAR Sectior 8.2.2.7, which describes the 120 VAC Vital Power system, was never updated to reflect the changes by the above mentioned ECNs.
The USAR is revised in July in every year based on a cutoff date in January of that year.
No record or tracking document was found to identify outstanding USAR changes based on closed ECNs.
There is a new procedure, issued 07-03-87, which should correct the problems if it is implemented properly.
However, unless all closed ECNs are reviewed many changes already made will be missed.
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ATTACHMENT 6.3 1
REQUEST FOR INFORMATION (RI)
RI NO:
144 SYSTEM CODE:
VBS ISSUE DATE:
08-17-87
SUBJECT:
_ OPERATIONS PROCEDURES FOR 120 VOLT AC VITAL SYSTEMS DO NOT REFERENCE TECHNICAL SPECIFICATIONS DEPARTMENT:
OPERATIONS COORDINATOR:
R. MACIAS/4589 TEAM LEADER:
T. MARSHALL /3965 POTENTIbl. CONCERN /0UESTION:
The inspection team has a concern that procedures, which place the plant l
in a Limiting Condition for Operation, do not reference the Technical Specifications or the Limiting Condition.
This could contribute to I
exceeding a Limiting Condition of Operation.
A.62, Rev. 10, 120 Volt AC Vital System, Draft, does not reference Technical Specifications 3.7.2.k of Amendment 147 even though Section 7.1, " Placing the 120 Volt Vital AC System in Maintenance Bypass '0PS'" places the plant in a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> LC0 condition.
A.62, Rev. 10, Draft, 120 Volt AC Vital System does not list Technical Specifications in the reference section.
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A.62, Rev. 8, 120 Volt AC Vital System does not list Technical Specifications in the reference section.
Draft Procedures C.157, C159, C.161, and C.163, " Loss of 120 Volt AC Vital Buses $1A, S1B, SIC, and SlD," do not reference Technical Specifications Section 3.7, even though being in these casualty procedures places you in an LCO.
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ATTACHMENT 6.3 L---------
l REQUEST FOR INFORMATION (RI)
RI NO:
145 SYSTEM CODE:
VBS ISSUE DATE:
08-17-87
SUBJECT:
UNDETECTED LCOs AND REPORTABLE OCCURRENCES DUE TO STATIC TRANSFER SWITCH OPERATION
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DEPARTMENT:
OPERATIONS COORDINATOR:
R. MACIAS/4589 TEAM LEADER:
T. MARSHALL /3965 POTENTIAL CONCERN /0UESTION:
The alarm logic and functions may not be adequately addressed for operations to properly assess the status of the system.
Operations of Static transfer switches H8TA3, H8TB3, H8TC3, and HBTD3 may cause entry and exi.t of Technical Specification 3.7.2.k of i
i Amendment 147, without operator knowledge, The static transfer switch transfers to the alternate supply on inverter fault, overload, or low voltage and will transfer back to the inverter as soon as the condition clears.
An alarm is received on the IDADS computer when the " transfer switch not on normal source" alarm is received on the inverter alarm panel, but when the transfer switch transfers back to the inverter, the inverter alarm' clears automatically.
Static switch transfers due to inverter glitches or voltage dips may result in many LCO conditions before the actual problem is I
discovered.
l CLOSED - Combined with RI #138.
1 ATTACHMENT 6.3 '
REQUEST FOR INFORMATION (RI)
RI NO:
146 SYSTEM CODE:
V8S ISSUE DATE:
08-17-87
SUBJECT:
'00ALIFICATION OF 120 VOLT AC VITAL SYSTEM COMPONENTS DEPARTHENT:
ENGINEERING COORDINATOR:
R. LAWRENCE /3849 TEAM LEADER:
T. MARSHALL /3965 POTENTIAL CONCERN /00ESTION:
The potential loss of vital equipment designated as " required for safe shutdown" because the equipment may not be properly qualified, a
The designed air flow has been modified by blocking the bottom entrance and cutting two holes in the front panel and adding filters. This was apparently done without an ECN.
1.
The air flow volume may not be sufficient to ensure adequate cooling.
2.
The air flow path may not be adequate to ensure cooling of transformer windings in the bottoin of the unit.
3.
A seismic analysis has not been performed to ensure'the modification has not invalidated the seismic qualification of the units.
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As a result of SMUD Audit Report No. 0-474 dated 07-26-82, Elgar was removed from SMUDs Approved Suppliers List.
There appears to be no documentation that the "Open Items" identified were resolved prior to receipt of the inverters.
SMUD Audit Report No. 0-474 Open Item No. 9 indicates that,
" Silicone controlled rectifiers purchased for the assembly of the l'
SMUD inverters did not have insulating skirts on their wiring terminations as required by specifications."
SMUD Audit Report No. 0-474 Open Item No.18 indicates that, "The SMUD contract inverters ' passed' Elgar's final inspection without correction of known nonconformances to the SMUD specifications."
SMUD Audit Report No. 0-474 Open Item No. 19A indicates, "The Class lE Acceptance Test Procedures (ATP) originally presented to SMUD and Bechtel did not reflect major test procedures required by the contract specifications."
l ATTACHMENT 6.3 i
RI 146 (Continued)
SHUD Audit Report No. 0-474 Open Item No. 19B indicates, "The QA review of the original Class 1E Acceptance Test Procedures failed to identify major discrepancies.between the ATP and the contract specification test requirements."
SMUD Audit Report No. 0-474 Open Item No. 23A indicates, "No inspection and verification document was prepared for any of the SHUD contract inverters."
Vertical Audit Report No.87-020 Open Item No. 87-020-019 addressed the issue that' ccrrective-actions regarding the deficiencies noted in SHUD Audit Report No. 0-474 were inadequate.
. The Elgar vendor manual' for the inverters specifies components which must be replaced on a routine basis to maintain the qualification of I
the inverters.
This has not been identified by the Preventive Maintenance Program or any plant program.
The inverters have been in service for over three years.
NCR No. S-3239 indicates circuit breaker 2A2127 was defective and I
was replaced.
From a review of microfilmed documents, qualification as Class lE could not be determined.
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ATTACHHENT 6.3 I 1
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REQUEST FOR INFORMATION (RI)
RI NO:
149 SYSTEM CODE:
VBS ISSUE DATE:
08-11
SUBJECT:
120 VAC VITAL BUS:
INVERTER 5 SIA2. $182. SIC 2. SID2 STATIC TRANSFER SWS-H8TA3_ H8TB3. H8TC3. H8TD3 DEPARTHENT:
ELECTRICAL MAINTENANCE _ COORDINATOR:
J. DARKE/4727 TEAM LEADER:
T. MARSHALL /3965 POTENTIAL CONCERN /0VESTION:
The 120 Volt AC Vital Bus inverters and static transfer switches are not adequately included in the Preventive Maintenance program.
Presently there is no h:tventive Maintenance with respect to the 120 Volt AC Vital Power System:
1.
To periodically replace, as recommended by the vendor in Instruction Manuals, capacitors, fans, and other components identified as age susceptible or limited life parts. Components with shorter lifespans are required by the vendor to be replaced to maintain the qualified life of the equipment.
2.
To include equipment failure experience in the plant that will require periodic inspection and/or replacement as determined by root cause analysis, (MAP-0017), trending analysis, and predictive maintenance.
3.
To include industry equipment' failure identified in the (NPRDS)
Nuclear Plant Reliability Data System that will require periodic inspection and/or replacement of components.
l ATTACHMENT 6.3