ML20073D644
| ML20073D644 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 03/31/1983 |
| From: | CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | |
| Shared Package | |
| ML20023B356 | List: |
| References | |
| NUDOCS 8304140083 | |
| Download: ML20073D644 (237) | |
Text
{{#Wiki_filter:__ . - _ _ _ _ - - _ _ _ _ _ _ _ _ _ _ _ _ - - - O Midland Plant Control Room Design Review Final Report O i March 31, 1983 i f a i I. I i j i 8304140083 830331
\ PDR ADOCK 05000329 E i f PDR 1
l ( TABLE OF CONTENTS Section Title Page INTROEUCTION 1-1 1 METHODOLOGY 1.1 Review Plan 1-3 1.2 Management and Staffing 1-4 1.3 Documentation 1-4 1.4 Review procedures 1-4
- 1. /. 1 Operating Experience Review 1-7 1.4.2 System Function Feview and Task Analysis 1-7 1.4.3 Control Room Inventory 1-17 1.4.4 Control Room Survey 1-17 1.4.5 Verification of Task Perfore.. ice Capabilities 1-23 1.4.6 Validation of Control Room Functions 1-23
() 2 GENERAL FINDINGS 2.1 Control Room Workspace 2-1 2.1.1 Multiunit Control Rooms 2-1 2.1.2 Control Room Manning 2-3 2.1.3 Ef fects of Unit Differences on Manning 2-3 2.1.4 Workspace and Environment 2-4 2.2 Panel Layout and Integration 2-9 2.3 Panel / Work Station Findings 2-11 2.3.1 Safeguards (2C14) 2-11 2.3.2 Primary (2Cl2) 2-12 2.3.3 Reactor (2C13) 2-13 2.3.4 secondary (2C11 Lef t) 2-13 2.3.5 Turbine (2C11 Right) 2-14 2.3.6 Common (CC10) 2-14 2.3.7 Electrical (2C15) 2-14 2.3.8 Post Accident (2C31) 2-15 2.4 Annunciators 2-15 2.5 Controls 2-16 2.6 Displays 2-17 2.7 Labels 2-17 2.8 Process Computer 2-18 2.9 Communications 2-18 i i
Section Title Page 3 IMPLEMENTATION 3.1 Overall Panel Improvements 3-1 3.1.1 Control Panel Enhancements 3-1 3.1.2 Panel Labeling 3-4 3.2 Controls 3-4 3.2.1 Reach Distance 3-4 3.2.2 TT-10 controller 3-4 3.2.3 Pushbuttons 3-4 3.3 Displays 3-13 3.3.1 Safety Parameter Display System (SPDS) /CRT Displays 3-13 3.3.2 Annunciators 3-13 3.3.3 Vertical Indicators (RY1200/RY2200) 3-14 3.3.4 Vertical Indicators (SIGMA) 3-14 3.3.5 Digital Indicators 3-15 3.3.6 Condenser vacuum Indication 3-15 3.4 Dedicated Components 3-15 3.4.1 Safeguards Split Screen Status Indicators 3-15 3.4.2 Core Map 3-16 3.4.3 Rod Control Panel 3-16 3.4.4 Main Steam Line Isolation valve (MSIV) Operating Panel 3-16 3.4.5 Emergency Core Cooling Conditioning Cabinet 3-17 3.4.6 Feed Only Good Generators (FOGG) Bypass Switches 3-17 3.4.7 Main Steam Line Isolation (MSLIS) Bypass 3-17 3.4.8 Power Operated Relief Valve (PORV) Maintain Contact 3-17 3.4.9 Emergency Core Cooling Enable to Sump Recirculation 3-18 3.4.10 Steam Generator Operate Range Level 3-18 3.4.11 Main Feed Flow Recorders 3-18 3.4.12 Emergency Boron System (EBS) Tank Level 3-18 3.5 Scheduling 3-19 Appendix A Human Engineering Discrepancies e ii
T" 4 ( ,/ List of Illustrations Figure Title Page 1-1. Sample HED Form 1-5 1-2. Sample Inventory Form 1-6 1-3. Event Structure 1-9 l-4. Events for Task Analysis 1-11 1-5. Functional Analysis Outline 1-13 1-6 Semple Task Analysis 1-15 1-7. Off-Normal Events 1-18 1-8. Sample Page HFE Cesign Checklist 1-21 1-9. Set Cesign Checklist 1-22 2-1. Midland Control Room Floor Plan 2-2 ('~'N 2-2. Maximum Reach ristances to Panels 2-6 (m ,' 2-3. Maximum Sight Distances 2-6 2-4. Maximum sight Angles 2-7 2-5. Maximum Sight Angles of Incidence 2-7 3-1. Cverall Panel Before and After Enhancement 3-5 3-2. Primary Panel 2Cl2 Eefore and After Enhancement 3-7 3-3. Secondary Panel 2CllL Before and After Enhancement 3-9 3-4. Safeguards Panel (Back) 2C24 Before and After Enhancement 3-11 List of Tables 1-1. IIFE Design Checklist Flag List 1-21 2-1. Differences Eetween Unit 1 and 2 Control Panels 2-5 l 2-2. Items Not addressed by HFE Cesign Checklists (~'} (../ 2-3 l iii
4 O INTRODUCTION This document constitutes Consumers Power Company's (CPCo) Detailed Control Room Design Review (DCRDR) Report for the Mid-land Nuclear Power Plant. On January 15, 1982 CPCo submitted to the Nuclear Regulatcry Commission the Midland Plant Control Room Design Review Program Plan report. That plan described control room design review efforts that formally commenced in February 1981. As a result of the progress made through December 1981, and guidelines from NUREG 6700, the Program Plan discussed a schedule and methodology from which the subsequent review efforts were to proceed. This report documents the results of the review effort to date and consists of three major sections, Methodology, Review Findings, and Implementation. Within the methodology section, the following four subsections will be included. e Section 1.1, Review Plan, provides a synopsis and status of the current work efforts and identifies those items
- that remain delayed due to construction status.
e Section 1.2, Management and Staffing, highlights O modifications in resulted since submittal of the Program Plan. utility support liaison that have e Section 1.3, Documentation, includes changes that have resulted since submittal of the Program Plan report. e section 1.4, Review Procedures, provides a synopsis e,f the procedures and methodology used in the design review i effort. Within Section 2, Review Findings, nine categories of find-ings are defined and discussed. An overview discussion provides the reader with a perspective of the types of discrepancies , identified. ' i Section 3, Implementation, discusses the modifications to be made to the control room to improve the man-machine interface and provides a schedule for completing outstanding items. 1-1 I .. _ _ . . _ . . , . _ , . _ _ _ , _ . _
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- METHODOLOGY 4
i j 1.1 REVIEW PLAN i l Following submission of the Program Plan report, two major
- work efforts commenced
- a detailed and functional task analysis, and control panel enhancement design. In addition, certain con-trol panel survey items not previously accomplished due to i construction were completed using the Midland simulator, which )
[ was undergoing operational testing at the manufacturing f acility. ' j In summary, the following design review items have been completed j since January 1982: 1 e Designed and documented control panel enhancements. l e Completed a detailed functional / task analysis using j i available symptom-oriented Emergency Operating Procedures ] (EOPs) guidelines. i l e Completed a formalized control panel inventory. j e Implemented enhancements on CPCo's full-scale mockup. I l e Conducted additional control panel survey items. 1 o Identified and documented additional HEDs from the T&ak ! Analysis. } j e Completed a verification of availability and human j engineering suitability. i l e Conducted a validation of control room functions. ! Due to the status of construction activities in the control } room, portions of the survey in the following areas could not be j performed in detail. e Control Room Workspace (Support Arrangements, Environment) i e Communications o Process Computers l Surveys in these areas will be completed followed by documentation of the findings prior to fuel load. l O l-3
i 4 0 1.2 MANAGEMENT AND STAFFING The Program Plan discussed the multidisciplined review team employed in the initial design review effort and provided a description of team and support members. In general, the review team functioned as presented in the Program Pl a n . The only deviation occurred when personnel from the Operations Department were not available due to scheduled training, simulator or shift work. In most cases other operations personnel were brought to the team meetings as necessary to support CRDR activities. 1.3 DOCUMENTATION The Program Plan provided a listing of Input Data used in the initial review, anticipated Input Data (to be used when available, for the DCRDR) , and Output Data. The Input Data was used throughout the DCRDR in various forms as needs dictated. The use of normal and emergency procedures was limited since they had not been approved or drafted in several cases. The symptom-oriented EOPs, i.e., Abnormal Transient Operating Guidelines (ATOG), were in the drafting stages and were used as they became available. Output Data were somewhat modified in format. The HED form was simplified, as illustrated in Figure 1-1. The control room inventory form was also modified to better support the verification of availability, of indicator ranges, and accuracy requirements. This revised format is illustrated in Figure 1-2. 1.4 REVIEW PROCEDURES This section describes the procedural process used in the control room review. This information is provided in six sections as follows: e Operating experience review e System function review and task analysis e Control room inventory e Control room survey a verification of task performance capabilities e validation of control room functions and integrated performance capabilities 9 1-4
- -- . _ . . . - - - . - . _ _e . . .- . .-.. _ _ -. . -
l 4 1 .i. (' HUMAN ENGINEERING DISCREPANCY 4 COMMENT: 1 1 LOCATION: DESCRIPTION: i 4 i 1 l 1 i I RESOLUTION: i l 1 - i ! l
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i i Figure 1-1. Sample HED Form l ( 1-5 i a- --n..- , , , - - - --,.n,-, ...r---- - ,n,,_n,,,__-. ,_. , . , , ,_ .. ... ,---_,e,-.,,-, ._ -_
I t PANEL 2C 11 PRIN T
- LABEL # SERvlCE NAME TYPE / DESCRIPTION UNITS QUANITY 24A 3949A2 FWC STM CEN FWP 2P-04A DSCHG 0-17C0 PSIG (Ligl 1 25A 394982 FWC STM GEN FWP 2P-04A DSCHG 0-1700 PSIG (Dig l 1 156A 3975AAI AUX FW TO STM GEN 2E-51A 0-1600 GPM 1 156C 3975BA * *
- 1 157A 3975 bbl AUX FW TO STM GEN 2E-51B 0-1600 GPM I 157C 3975AB " " *
- 1 124A 3931A APWPT 2G-05 SPEED INDICATOR 0-6000 RPM (Dig 1 125A 4930A COND STOR TE 27-06 0-100 PERCENT I (Dig 126A 3908 AFW PUMP TURB 2G-05 MAIN STM LO PT DR TRAP 126D 3298 AFW PUMP TURB 2G-05 MAIN STM LO PT DR TRAP K L TOR WITH 2 SETS OP LIGHTS 1EA 160A 3971A1 COND STOR TK STATUS UNIT 2 160C 397181 COND STOR TK STATUS UNIT 1 3 WHITE LIGHTS 3 160E 3971A2 COND PUMP STATUS Ch 161a 3975AA STM GEN 2E-51A LEVEL SETPT RESET BLACK RESET BUTTON 1 162A 3975AS STM GEN LEVEL SETPT RESET BLACK RESET BUTTON }
163A 3975BB STM GEN 2E-518 LEVEL SETPT RESET BLACK RESET BUTTON 1 164A 3975BA STM GEN LEVEL SETPT RESET BLACK RESET BUTTON 1 143A 3975AAl STM GEN AFW IND CONTPOLLER (CEN A) DUAL RANGE INDICATOR 0-96/0-600 INCHES 1 144A 3975A81 * * * " * * = 3 145A 3975BB1 * * " (GEN B) " * *
- 3 146A 3975BA1 * " * *
- g 147A 3931 AUX FD PUMP TURS 2G-05 1000x3600 RPM 1 31A 3934 FWC FAST MU AND FILL TO HOTWELL 0-100 1 318 3921 COND RECIRC FLOW CONTROL 0-5000 INCHES H '} I 2
31C 3799B DEAER HEATERS 2E-03 A&B PRESS (MAIN STM) 0-300 PSIG 1 31D 37998 DEAER HEATERS 2E-03 A&B PRESS (AUX STM) 0-300 PS3c g Figure 1-2. Sample Inventory Form O O O
l i l 1 4 i !O
- 1.4.1 Operating Experience Review
( l The Program Plan report discussed the initial review of operational documentation, and the survey of operational l personnel. Examples of reactor operator (RO) and senior reactor operator (SRO) questionnaires were also provided in the report. As indicated in the Program Plan, additional surveying of Midland personnel would not yield significantly more operational know- ! ledge. Instead, it was determined that review of recent operat- ! ing experience at other similar NSSS supplied plants would yield i more meaningful information. This review was performed to deter- { mine the extent that transients encountered at plants similar to j Midland could be included in the DCRDR. I J Within the period from January 1980 to April 1982, signifi-cant transients that occurred in seven similar NSSS plants were l reviewed. The review results were categorized, such that addi-tional evaluation of their suitability to the Midland design ] review effort could be performed. Several categories were elimi-i j nated due to design differences between Midland and the plant
- where a particular transient occurred. One category identified l arrangement discrepancies where system indicators and related 1 controls were not optimally located; this resulted in operator j difficulty in controlling the event. These types of situations l were generally plant specific. For Midland, the functional eval-i s uation of panels considered indicator control relationships as j part of the top-down task analysis.
1 l The final category considered appropriate to Midland t involved failures of specific systems including plant indication j and control systems that resulted in significant plant tran-j sients. These failures were evaluated as part of the task j analysis, ensuring the control panel configuration contained the
- indication and controls required to maintain the plant in a safe
! condition in the event of those system failures.
- 1.4.2 System Function Review and Task Analysis 1
l The review and analysis generally followed the approach i suggested in the NUREG 0700 guidelines. It was conducted in four ) major steps: J
- e Preparation for Event Definition i
e Event Definition 9 j e Functional Analysis i e Task Analysis J b 1-7 i ^
i Considerable effort and attention was devoted to the initial stages of event definition in order to ensure a well organized framework on which to base the extensive analysis effort. The process was significantly accelerated by the availability of
; plant specific ATOG guidelines in the draft form, prepared by l Babcock & Wilcox. Also useful were detailed timeline analyses for some normal operations.
l i 1.4.2.1 Preparation for Event Definition. This initial organiz-ing process constituted a significant portion of the analysis
! effort. Operating events were initially sorted using the exten-
] sive operating procedures index, and were classified and categorized into major areas of operations. These events then were compared with the major plant operating systems, subsystems, and equipment lists to ensure complete coverage. All systems, subsystems, and equipment of the primary, secondary, and balance of plant that are controlled from the control room were included on the list. l Events were then organized by categories and related as shown in Figure 1-3. Beginning with the operating objective, the major categories were defined as Normal Operations, O f f-No rmal Condi-tions, Emergency Conditions, and Test Operations. These were further subdivided as Figure 1-3 shows. Normal operation falls into six modes of plant operation. These modes were combined into four baseline operations: Heatup, Startup and Power Opera-tions, Shutdown, and Cooldown. Each subdivision of this figure was investigated to determine possible operating events. A preliminary list of operating events was prepared by a subcommittee consisting of operators, engineers, and human factors specialists. All possible operations were reviewed for
- each of the subcategories of Figure 1-3. Where operating
, procedures existed, they were used to help identify types of , operator actions required to control the plant. The emphasis was placed upon substantive operating events wherein the operator must perform a sequence of events that are different from other sequences. This review also identified automatic operations that the operator is required to monitor to detec* improper action or malfunction. l.4.2.2 Event Definition. The primary purpose of this effort was to identify those operating events that required a detailed task analysis. The task analysis requirement was bounded by two assumptions. First, normal operation sequences (heatup, cool- ! down, etc.) would be subjected to complete task analyses includ-ing all functions. For example, the Heatup event would start from the completely shutdown state, steam generators in wet layup, pressurizer with nitrogen bubble, and so on. From that point all steps up to the beginning of the Startup event would be 9 1-8
1 o O O SAFE AND RELIABLE POWER AND PROCESS STEAM TEST NORMAL OFF-NORMAL EMERGENCY i OPERATIONS OPERATIONS CONDITIONS CONDITIONS I I I I I l l PHYSICS BALANCE SURVEILLANCE OF PRIMARY SECONDARY TESTS PLANT I l REACTOR SITE 7 TRIP EMERGENCY i I I l l _ l OVER OVER TUBE C NG MARGIN COOLING HEATING RUPTURE I l l l l l POWER LOW PWR HOT HOT COLD OPERATION OPERATION STD8Y SHTDN SHTDN I STARTUP & POWER OPS. HEATUP l SHUTDOWN COOL 90WN 'l i Figure 1-3. Event Structure
- 1
- s 1 1 included. Similarly, the Startup event would carry through to , full power operation, and Shutdown and Cooldown would reverse the I process and continue to depressurization for refueling. This then would account for the normal operation of most systems and equipment in the primary, secondary, and balance of plant. l Therefore, during analyses of casualty and emergency conditions, any operation that would be performed using normal procedures would be referred back to the normal operations task analyses. The second assumption was that the symptom-oriented EOPs (ATOG) were designed to handle any occasion of a reactor trip. Therefore, a reactor trip, no matter what the cause, would be handled in accordance with the ATOG. These ATOG guidelines would be subjected to a detailed task analysis. The remaining work of event definition centered on identifying of f-normal operational conditions that do not result in an unavoidable reactor trip and require a task analysis. The criteria for requiring a task analysis was that there be a sequence of tasks to perform, as opposed to a single, simple action, and that the sequence include some operator actions that were different from other task sequences to be analyzed. The review of the candidate list of off-normal events by the review team revealed many sequences that were included within the actions of more complex events. The larger events therefore covered all the included events. Therefore, those events in-cluded in the complex sequences were not listed independently. Detailed discussions of hypothesized events were conducted to bring out the most basic safety related events. Babcock & Wilcox was represented during the event definition discussions to pro-vide technical assistance to the team in identifying significant events and their consequences. From these discussions, the list of Events for Task Analysis was defined. Figure 1-4 contains the chosen events. A review of test operations revealed two types of tasks: (1) those that will be performed routinely by the operators, and (2) those that constitute special tests for which special procedures will be prepared when required. Only the first type can be analyzed at this time. Analysis of surveillance requirements indicated a distinct break between operations to be performed at a frequency of 30 days or greater, and those to be performed less l frequently. Because the nature of requirements for a frequency of greater than 30 days indicate the need for special procedures, only less-than-30-day frequency surveillance requirements were analyzed. Likewise, physics testing will also require special i procedure preparation for each test and will be based upon normal l operating procedures. Such special testing requirements will be l reviewed for safety when test procedures are prepared. O l-10
4 l 1 1 I l 4
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I j NORMAL OPERATIONS 1 Plant Heatup
- Plant Startup and Power Operation I
Plant Shutdown ! Plant Cooldown i Plant Preparation for Refueling
- Rod Control Operations j Boration/ Dilution Operations l OFF-NORMAL OPERATIONS Primary I
. Pressuriser Spray and Heater Malfunctions Asymetric and Dropped Rod Impending Loss of Coolant Pump , .! Control Rod Drive Control Faults i ! Loss of Letdown l 2, Selected NNI/ICS Instrument Failures j Anticipatory Transient Without Scram (ATWS) l l l Secondary ' Partial Loss of Steam Generator Feed i Partial Loss of Condenser vacuus Turbine Trip with Runback e I Abnormal Main Steaaline Header Pressure 4 Partial Loss of Condensate Selected NNI/ICS Instrument Failures Balance of Plant Loss of Instrument Air Evaporator Steam Mode Transfer (Unit I to Unit 2) i EMERGENCY OPERATIONS (Reactor Trip) i, 1
, Abnormal Transient Even ts (Sympton Oriented) ! Reactor Trip Loss of Primary Subcooling
} Primary Overcooling j Primary Overheating Steam Generator Tube Rupture l Transient Support and Follow-u p l Ruptured Tube Cooldown j Cooldown with H.P. Injection (Large LOCA) i Saturated Primary Cooldown (Small LOCA) Cooldown Following Inadequate Core Cooling i Throttling Auxiliary Feedwater Maintaining Appropriate Steam Generator Level j Restarting Main Coolant Pumps after Restoring j Primary Subcooling i a l l Figure 1-4. Events for Task Analysis 1 ) i s- / 1-11 l 4 i
I Surveillance is conducted in accordance with plant Technical Specification, which describes these tests. This document was analyzed to identify control room operator requirements. Since all such actions are simple and straightforward, the task analysis was completed by identifying the conditions under which the surveillance is performed, and the adequacy of controls, indications, and feedback. No substantial task sequences were identified. Site emergencies had been subjected to a previous analysis in the preparation of the Site Dmergency Plan. This plan, already completed, identified control room operations required to support each type of site emergency, and specified controls and indications to be used. This plan was reviewed and found to meet the requirements of the DCRDR for those types of operation. 1.4.2.3 Functional Analysis. In establishing the analysis process, the sequence of analysis is very important. As a base-line, the four normal operating events were chosen to establish a point of departure. All system and equipment normal operations were covered in these baselines. Then the emergency operations were analyzed, based upon the plant specific guidelines already developed by the NSSS vendor. These two major efforts thereby covered most of the operator manipulations of the major systems and equipment. The off-normal operations were analyzed last, referring to normal and emergency tack analyses where appropriate. The functional analysis approach took slightly different forms depending upon the type of operation. Normal operations were treated as sequential timelines. Emergency operations were subjected to extensive multiple failure event tree analyses, and then symptom-oriented functional flow diagrams were developed, including branching and loops where required. The latter analysis was performed in great detail by Babcock & Wilcox during the ATOG development. Functional analysis for normal procedures was developed using a simple timeline where each step is a prerequisite to the next step. Because normal plant operations are conducted in a deliberate manner and the operator can control the rate of progress, the timeline was needed only to sequence the tasks properly. There was no occasion found to be time limiting. Therefore, the functional flow was recorded in an outline format which lends itself to further task analysis. A sample of the format is shown in Figure 1-5. l The functional analysis used source documents and draft operating procedures when available. Participating operators had extensive experience on other plants and were thoroughly trained on the Midland plant. Engineering expertise was provided on systems, controls, and indications. ll l-12 l . i
1 O FUNCTION 08JECTIVE ACTm PRIMARY Stop Coolant 1. Trip all coolant pumps on PRESSURE Pumps safeguards panel H.P. In) 1. Initiate H.P. In):
- a. BWST suction open (2)
- b. Inj valves open (4)
- c. Start second Makeup pump
- d. Close Makeup tank outlet (2)
- e. Close Inj recire valves (2)
- f. Close letdown isolation
- 2. Verify injection flow greater than minimum for coolant press-ure (Rule 1)
- 3. With two pumps running:
verify no more than 300 gpm flow on each meter (Rule 1) O s ,,/ Stm Gen Levels
- 1. Raise Stm Gen level to 95% oper-ating range IF compensated level not available
- a. Use WR level with pressure in Figure 4
- 2. Thrott7e Aux Feed (Rule 3)
- a. Determine if natural circula-tion by comparing Stm Gen temp with incore T/C Figure.1-5. Functional Analysis Outline l i
O l-13 l l
l l Functional analysis for emergency operations were performed, as described above, in the development of ATOG. These symptom-oriented guidelines are initiated with a reactor trip. All reactor trips, other than the normal shutdown procedure, will use these procedures. Because of the extensive nature of the emer-gency operating guidelines, an additional functional analysis was performed to determine which parts required a detailed task analysis for the control room review. Many of the branching alternatives are repetitions in the functions and tasks they perform. For this reason, the functional analysis outline covered those operations once, and did not repeat them for each event sequence. In addition, special equipment operating rules for emergency conditions, which are part of ATOG and must be , applied whenever the appropriate conditions occur, were included in the analysis. Finally, outlines were prepared for of f-normal operations covering the specific events listed in Figure 1-4. This analy-sis, like that for the normal operations, used draft procedures, source documents, and operator and engineering expertise to develop the outlines. Of the possible failures that could lead to each of the events listed, the worst case was determined and developed for this analysis. Then each case was reviewed to ensure it included all important elements and was truly representative of that type of event. Many initiating events considered were merely part of a more important event such as Reactor runback, and otherwise involved relatively inconsequen-tial actions. Some of the listed events, upon analysis, did not involve a significant sequence of events but rather consisted of one or two simple control manipulations with direct feedback. In each of these cases, the analysis of the task was performed immediately, identifying the indications, controls, and feedback, as well as necessary conditions and requirements. 1.4.2.4 Task Analysis. The task analyses were performed by the review team and comprised the major portion of the analysis effort. These reviews were conducted at the full-scale control room mockup so that the control panels were immediately avail-able for reference. Although primarily a paper study, difficult sequences were walked through and talked through at the mockup. Input data were continually available. Where it was considered beneficial, the task analysis sequences were walked through on the actual control room panels to the extent the under construc-tion panels were available. Functional analysis outlines were expanded with a format that provided columns for recording task information (see Figure 1-6). The functional analysis provided a minimum of four levels of task breakdown. Those columns describe the function (PHAS E) , task O 1-14
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i objective (STEP), task action or decision ( ACTION) , as well as condition or control names. Added to these three columns were five additional columns. The indication (IND) column identified the type of indication or system response feedback that is re-quired, and for each control action, the type of control used. Specific readings or range of readings to be expected, and the reading accuracy required were listed in the reading'and accuracy (READ /ACC) column. Dynamic response of indications and control precision were considered at the same time and any discrepancies were noted in the comments column. References (REF) were noted in the column provided, and another was provided to identify (ID) the number of specific controls, and indications, including the panel number. Finally, a column was provided for comments and indication of discrepancies. Inherent in the symptom-oriented approach to the o f f-no rmal and emergency procedures is the consequence of errors and omissions. Since the symptoms are treated directly, errors and omissions will alter the flow of system progress and create new sets of tymptoms. These new symptoms, in turn, will be treated by the operator following the multipath procedures. Therefore, the operator automatically corrects for errors and omissions by following the procedures through applicable alternative paths. The review team considered whether a particular task action or procedural step was prone to error. On one occasion, branching procedures were judged too difficult for an operator under stress to follow without errors in decision making and, possibly, follow-up action. This information was input to the authors of the ATCG draft for consideration in ongoing revisions to the guidelines. Application of the task analysis process followed the functional outlines. Tasks were analyzed based upon the k no w-ledge of highly qualified and experienced operators, engineers thoroughly familiar with instrumentation, controls, and plant operational requirements, along with source materials. The team was led by experienced human factors personnel. During the task analyses, the team thoroughly discussed each task and subtask in the context of the function being performed. Frequent references were made to the mockup to identify controls and indications. Because the mockup is a full-scale complete replica of one unit's control panels, it also provided a presence of scale and proportion to aid in thinking through the effects on operators in identifying problems and in making decisions, and requirements for physical movements between panels. System auto-matic actions, interlocks, and safeguards actuations were identi-ficd at each step. Controls and the principal or preferred instruments that provide information and feedback were identified by name and identification number. The panel numbers for each ID O l-16 i
1 ] 1 l !() j were arranged in a vertical column so that operator movement could be easily followed. Instrument readings and accuracies j i were considered for each task or subtask as a function of that j task. 1 A task analysis, as described above, was completed on all j normal and emergency operations that are initiated with a reactor 4 trip, as listed in Figure 1-5. Not all off-normal operations listed required the full task analysis. The off-normal events fell into four categories: (1) those requiring a full task ; j analysis, (2) those resulting in a reactor trip before the opera- ; { tor could take effective action, (3) those too simple to require i l a full task analysis, and (4) those whose actions were adequately covered by normal, emergency, or other o f f-no rmal operations already subjected to task analysis. The specific disposition of j o f f-no rmal events that were listed in Figure 1-4 are summarized j in Figure 1-7. j i ) 1.4.3 Control Room Inventory 1 The control room inventory originally was considered neces-sary to establish a reference set of data which identifies all
- instrumentation, controls, and equipment within the control room,
! for comparison with the requirements identified through the analysis of operator tasks. () pared presence or verified against the task analysis to The inventory would then be com-(or absence) of instruments and equipment that provide identify the the information and control capabilities necessary to implemen't
- each task.
4 A systematic panel-by-panel inventory of components was conducted and documented. A verification of availability was conducted using the task analysis as described in Section 1.4.2. l As a function of the event definition process, which focused on j normal, off-normal and emergency operations, not all control room functions were considered. This fundamentally diminished the 1 overall objective of the inventory. The process employed did j verify the availability of control panel components for the l l events selected. Since the events selected considered the most l operationally significant control room situations, the inventory verified their availability. 1.4.4 Control Room Survey 1.4.4.1 Human Factors Design Review. The human factors engin-i eering (HFE) design review (control room survey) of the Midland Unit 2 control room was a systematic evaluation using the latest
- standards as design criteria. These standards included NUREG/CR-1580, NUREG-0659, NUREG-0700, MIL-STD-1472B, and Van Cott and
! Kinkade (Human Engineering Guide of Equipment Design, 1972). !O ) 1-17
A. PRIMARY 1
- 1. Pressurizer spray anu Heater Malfunctions After a detailed review of possible failures and corrective actions to be taken, it was determined that all tasks were straightforward and simple, not requiring a for-mal task analysis. The team did, however, review all tasks to ensure instrumentation and controls were adequate.
- 2. Asynetric and Dropped Rod A review of this group of casualties revealed no rod control manipulations that had not already been covered in Normal Operations or during the Reactor runback portion of Turbine Trip.
- 3. Impending Loss of Coolant pump The impending loss of coolant pumps can be caused by bearing temperatures, seal failures, loss of cooling, vibra-tion and loss of primary subcooling. The actions related to these events are adequately covered by the ATOC analysis, runback, and loss of letdown casualties.
- 4. Control Rod Drive Control Faults No significantly new operations or indications to be analyzed werp discovered beyond those covered in normal operations and runback casualties.
- 5. Loss of ;etdown Loss of letdown was analyzed in detail. A task analy-sis was performed to emphasize alarms and component cooling.
Other letdown functions were covered under Normal Opera-tions, and particularly ATOG.
- 6. Selected NNI/ICS Instrument Failures An analysis of NNI instrument failures led to consider-ation of four failures for the primary systems Tc fails
! high, Tc fails low, Th falls high, Th fails low. Of these, l a task analysis was performed on two: Tc fails high, and Th I fails high. These two failures would allow reasonable time i for the operator to take corrective action. Failure low of Tc and Th would result in Reactor Trip within 99 sec. and 28 see. respectively. Because these failures would most likely not be interpreted and corrected in the time available, they were not analyzed further.
- 7. Anticipated Transient without Scram (ATWS)
The actions required for this category of transients is covered by ATOG and the boration procedures. ATOC addresses ATWS to the extent that the operator is instructed to manually trip the Reactor and to start emergency boration if neutron counts are not decreasing. Figure 1-7. Off-Normal Events 1-18
n- - B. SECONDARY
- 1. Partial Loss of Steam Generator Feed C The major requirement on partial loss of feed is a runback to 684 power.
runback procedure. This has been covered in the Reactor
- 2. Partial Loss of Condenser Vacuus A task analysis was performed to emphasize the manipu-lation of cooling water and air' removal systems in order to regain vacuum.
- 3. Turbine Trip with Runback Of major importance in this procedure is the runback of reactor power. A task analysis was performed for Turbine Trip and runback to a stable condition. The runback process covered many other casualty conditions the team analyzed.
- 4. Abnormal Main Steam Line Header Pressure The team analysis showed that only the header pressure failure low caused significant problems, and that resulted in a reactor trip within 15 sec. ATOG procedures apply.
- 5. Partial Loss of Condensate various failures that would not result in esactor trip were analyzed. Of these, the Low Hotwell Level was chosen for task analysis as being representative of these types of failures.
O 6. Selected NNI/ICS Instrument Failures The analysis selected four secondary failures of signi-ficance: Feed control valve aP low, Steam generator startup level low, Steam generator operate range level high, and Header pressure low. A task analysis was performed on the first two. The second two would result in a reactor trip within 38 sec. and 15 sec. respectively, and were covered by ATOG. C. BALANCE OF PLANT
- 1. Loss of Instrument Air A study by Bechtel identified valves affected by the loss of instrument air. It was determined that a complete loss of instrument air would result in a reactor trip. A task analysis was performed for a gradual loss of instrument air with sufficient time to identify the cause and restore instrument air without a reactor trip.
- 2. Evaporator Steam Mode Transfer The process of shif ting evaporator steam from Unit 1 to Unit 2 has been the subject of lengthy study by Consumers Power. It has resulted in the design of an automatic system for transfer. An analysis of the system revealed that a successful transfer could be accomplished automatically since the maximum evaporator load will be 484 and the shift will be ramped to prevent excessive rates.
l Pigure 1-7. Off-Normal Events (Continued) i I i 1-19
l This portion of the overall evaluation was to determine if the workspace and instrumentation was in compliance with HFE design criteria. The methodology categorized the equipment being evaluated by levels of complexity. These levels were identified as component, set, and panel. A sample page of a component HFE design checklist (Figure 1-8) and accompanying list of flags (Table 1-1) is an example of the depth and format in which the components were reviewed. A flag is a note or explanation to the review team describing either the status or the inconsistency of the review item. The first and most fundamental level of the Control Room Survey was the component review. Thirty-nine categories of similar type components were identified; i.e., two varieties of indicator lights, annunciator tiles, four varieties of J-handle selectors, three varieties of pushbuttons, etc. A single component was selected to be representative of each category. The checklist addressed design characteristics of the components that remain consistent for all similar types, regardless of their application. This checklist was administered on the actual l panels in the semi-completed Midland Unit 2 control room. l Components represented on the panels were visually inspected and evaluated for manipulation and limited operation. The components not yet installed were evaluated using representative photographs on the mockup. These components were subsequently reevaluated on the Midland simulator. The second level of the Control Room Survey was the set design. A set is defined as a unique arrangement of components which (1) serve a common function, (2) are repeated frequently throughout the control room, and (3) are identified by a single, common placard. Fifty-three categories of similar type sets were identified in the Midland plant. Again, one set was selected to be representative of each type of set. It was evaluated using the " Set Design Checklist" (Figure 1-9). This checklist primarily addresses relative arrangement of components in the set, as well as movement relationships between the components and identifi-cation (component legends and placard labeling) within the set. The administration of this checklist required descriptive data - about the components available from the Component Design Check-list, and an accurate description of spatial relationships avail-able from the mockup. The panel review provided the third level of this survey. This was a top-down functional operational review, whereas the component and set review was a bottom-up approach. The functional evaluation consisted of a review of control / display relationships, the ability of system functional grouping to support system understanding and how the console grouping related to overall plant operations in normal and emergency conditions. 1-20
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. et 458 yes/no
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$4 Tlere ese re sPessus en trie consowt, even from tre poteter yes/re 33 Dere is re speetts! glare er reflection from tre comprent . et 908 yws/no
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Sty &e sW*rd . Point sias er retqrt iM ou treen 34 Curaeter Petywt/=leta rette, strahe egetn se specisg is car.enttarel rer fant yes/no 39 Scale rueers are in eneolute volves (i.e., ret 110.1100, etc.) yes/no 40 S.S.2 all legeres . are erte yes/re
. are reed left to rap res/re 6 al S. 2. 6 Ca.riters are Flags are emMoo close to tre cogenere marface yes/no e/ A 4 42 S.2.1 Scale desigs is 6aagerstrinic strer 43 units represented by . enjor 0 reticule I
- 30 3
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- IS
= auer Orattaale .L =3 Figure 1-8. Sample Page HFE Design Checklist TABLE 1-1. HFE DESIGN CHECKLIST FLAG LIST
- 1. Information on normal operating range was not available at the time of the evaluation.
- 2. Pointer obscures portions of the legend but is narrow enough to view the number.
- 3. Pointer is red but does not conflict with color code.
6 Legend ts aligned vertically (i.e., one letter above the other).
- 5. Scales are not compatible. Even enough they indicate different measures (i.e., amps and volts), the scales should read in similar units (i.e., 1-5-10-etc., not 3-15-30-etc.). -
- e. There is no discriminacton between major and intermediate graticules.
- 7. Information of component reliability, f ail-s a fe operations, and failure modes was not available at the time of the evaluation.
tu/ i l-21
f- - O SET DESIGN CHECKLIST CONTENTS DESCRIPTION I (list co9ponents) (style) tamount) l (sketch) l l IN DIC A TOA UGHTS 2 KNOS SELECTOR 1 G R OO i l 1 O l l i M CheCumarm (/) An the column Ano1 Cates that all Considerations Of each WE Cesign criteria were applicable to the-set design. The con. siderations are listed in Appencim 8. Considerations whien do not apply indicate a non-corpliance with WE cesign criteria. These are icentified in the column by the consiceration numoer insteaa of a check. mark. HFE oEllGN cRITE RI A
/
~ / 2 PANEL $ET DESIGN LOCATION ,
IDE NT: Fica TION S[ gv .,Sf[ vOi y vg OBSE RVA TIONS ocicR oMo-soi4A v v / v' / / } "HP" ABBREV. ONLY OlF F. 8 ; / / / / / ) oMo-soosA y / / / / / } "LP- AseREv. oNLY Ol F F. 8 / / V / / / ) OMo-sosaA / / / / / / 8 / / / / / / ouo-soisA / / / / / / e / / / / / 4 c / / / / / / O / / / / / / E / / / / / / F
/ / / / / /
l 4 Figure 1-9. Set Design Checklist O 1-22 j
' () Panels were reviewed individually to determine their function with respect to overall plant control. Next, an evaluation was made of functional arrangement of controls, displays (indicators) and annunciators with respect to groupings, and consistency with plant configuration. Finally the relationship of panels to one another in an operational context was evaluated. 1.4.5 Verification of Task Performance Capabilities l 1.4.5.1 verification of Availability. A verification of availa-bility was performed.-- The mockup served as the physical inven- l tory of the control room. As each task was performed during the talkthrough, the availability of the appropriate control or indi-cation was verified (or absence noted). It was also noted when only an indirect measure was available. Dynamic characteristics and accuracy were considered using actual control panel indicators in the partially completed control room or the plant specific simulator (which was also under construction yet had 95 percent controls and indicators in place) and the detailed task analysis. l.4.5.2 Verification of Human Engineering Suitability. A thorough verification of human engineering suitability of the control room panele was performed. Panels were analyzed for functional and spatial arrangements both within each panel and between panels. O The analysis used panel arrangement drawings, technical and training material, and piping and instrumentation drawings. Emphasis was.placed on requirements for the operator to identify and diagnose the causes of abnormal transients. The need to correlate information from several panels was studied for transient conditions. 1.4.6 Validation of Control Room Functions The objective of the validation process was to determine whether the operating crew can accomplish its functions effectively using: e Tne event sequences provided (both normal and emergency operations) . e The control room display and control system. Validation emphasized the ability of the operating crew to ascertain and evaluate plant status, and to diagnose transients. The process was not to validate procedures, but to validate the control room. i O l-23
l l l l l For the initial design rcview, talkthroughs and walk- h throughs were conducted using the control room mockup as ! originally configured (before enhancement improvements were made to the mockup) using various operators from the plant Operations 23partment. It should be recognized that this effort was conducted in the context of data gathering early in the design review process. This activity is documented in the Program Planning Report. The following discusses how each of the event sequences were first talked through, then walked through in near real time and recorded during the actual validation using the enhanced mockup. Talkthrough. The talkthrough consisted of a rehearsal for the walkthrough. One person acted as supervisor who read the phase, step, and action to be taken. The lead operator and support operator discussed how they would perform the action. Since this is not a test of the operators' knowledge and abilities, those present were encouraged to comment and assist in the discussion. The operators were asked to locate indications and controls on the mockup for each action during the talkthrough and identify problems in any of the following areas: Operator Workload: Do operators have reasonable time to perform the actions required? Team Confusion: Are the operators able to coordinate their efforts and understand what they are doing?
"What if": If the expected result is not achieved, what should be done?
Error Prone: Is the specific arrangement of displays of controls apt to cause operator error? Instrument Interpretation: Do operators have to convert readings 'to other units or perform mental arithmetic to interpret meaning? Operators were encouraged to make any comments on the adequacy of the control room design, or to comment on missing information. Walkthrough. When the talkthrough was completed, three operators took station to walk through the event sequence in near real timu. One operator read the sequence of phase, steps, and actions, while the lead operator and support operator walked through the actions. As each action was read out, the lead operator indicated who should carry out the action. A designated operator performed the action as follows: O l-24
D) (, Information: Identified and pointed to indications he would use to determine status, and state any reasoning he uses to decide upon action to be taken. j Action: Pointed to and named the controls that h9 would manipulate and specify in what position he will place the controls. Feedback: Identified and pointed to indication he would use to verify that the action was performed and those that will indicate system response. Indicate the response expected. The operator reported the completion of the action to the supervisor (reader) so that he could continue with the next action. The walkthrough was recorded in audio and video as a backup to the actual data collection, and for future analysis as required. The operator could stop action at any time to ask questions or clear up points of confusion. Observers asked questions that might clarify points concerning the adequacy of control room design during the walkthrough. Whenever a long period of slow change in plant parameters occurred, the timing would be described and the operator noted
% what instruments he would monitor and what limits he would observe. Then the time was accelerated to the next action in the sequence. Upon completion of the walkthrough, operators gave further comments they had about the control panels relating to the sequence just completed. Observers asked questions of the operators concerning the sequence.
Record Keeping. In addition to the audio-video record of the walkthrough, a hard copy of the event sequence was used by data collectors. Problems or discrepancies noted during the talk /walkthrough were noted on those sheets. Notes designated discrepancies by the team leader were marked 'HED' in the right hand margin. (Those HEDs previously identified during the task analysis were already marked 'HED' in the right margin.) The event sequence sheet also lists the panel numbers for each step so that the movement patterns were already identified. Any changes were noted. In addition, a chranological record was maintained of specific problems identified, not all of which would necessarily be HEDs. I 1 1-25 1 - -
Section 2 GENERAL FINDINGS This section highlights the findings obtained from the DCRDR, and is divided into categories that generally follow the human engineering guideline categories contained in NUREG 0700, Section 6. The categories covered include: Category 1 Control Room Workspace 2 Panel Layout and Integration 3 Panel / Work Station Findings 4 Annunciators 5 Controls 6 Displays 7 Labels 8 Process Computer 9 Communications 2.1 CONTROL ROOM WORKSPACE 2.1.1 Multiunit Control Rooms The Midland plant consists of two NSSS units with both control rooms in the same space. The control panels for each unit are arranged side by side, separated by a detached panel that controls common auxiliaries. A feature of this dual unit arrangement is the capability to supply tertiary steam to the Dow Chemical Company in addition to generating electric power. Both units will be able to supply both loads. The general floor plan of the control room panels is illustrated in Figure 2-1. , I The two unit control panels are a mirror image of one 1 another in the sequence of individual panel arrangement. In contrast to the panel arrangement, individual panels are essen-tially identical. (i.e., Standing in front of any panel, it would be difficult to tell whether it was Unit 1 or Unit 2.) Considerable emphasis was given in the review process to the O' effect on an operator of switching from one unit to the other. Since each individual panel is the same arrangement, no effect 2-1
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( 'l i should be realized while operating that one panel. An operator O,' could, however, turn in the wrong direction to proceed to another panel. After detailed involvement with the panels, and exper-ience with the procedures during task analysis and valkthroughs, it was possible to further evaluate the effects of the reversal of the sequence of panels. The differences between individual panels within each unit are distinct, and will be accentuated by panel enhancements. The effect of turning the wrong way was evaluated for each panel. In all cases, the initial movement in either direction was to turn the head and eyes. The operator immediately ciscerned that the panel in his direction of vision was the wrong panel, taking at the most one step, then moving immediately in the other direc-tion. It appeared that a licensed operator would experience no confusion. With the many distinctive visual cues available, this recognition remained on the intuitive level. In most cases, peripheral vision provided these cues, with no initial misdirec-tion occurring. It was determined that any misdirection that an operator might encounter would delay his movement in the right direction no more than one second, and that this would not add to his cognitive workload. As a result of overall operational requirements of this unique arrangement, the location of the Common Panel between Unit 1 and Unit 2, and the control room team organization, the mirror imaging effects will be minimal if at all present. 2.1.2 Control Room Manning During the process of the design review, the review team concluded that two operators (RO) were necessary to operate each unit. During high stress transients, the two operators will work with a supervisor (SRO) as a team. They will be trained and function as members of an operational team, which will allow better coordination of operators using controls and instruments on various panels, and will aid in diagnosing plant problems. 2.1.3 Effects of Unit Differences on Manning ! It is planned to rotate shift personnel between operating units. Therefore, the differences in units was thoroughly studied. The major differences between the plant designs is that Unit 1 has only one low pressure turbine where Unit 2 has two low pressure turbines. This difference is necessary because the Unit 1 high pressure turbine uses extraction steam to provide steam to the Dow evaporators more efficiently. Both units can provide main steam to Dow evaporators directly using identical piping and reducers. The intent is that when both units are operating, Unit I will provide the steam to Dow (about 40 percent of the total load capacity) because extraction steam can be used e- for higher efficiency. When Unit 1 is not operating, Unit 2 will (N) provide steam to Dow. All remaining capacity will be used to generate electricity. 2-3 1
. 1
The control panel differences between units due to the additional low pressure turbine on Unit 1 are minimal. Unit I has one vacuum readout instead of two. The Electro-Hydraulic Control Panels for Unit 1 have controls for only one L.P. tur-bine, while Unit 2 has two. These panels are arranged consis-tently so that the differences are obvious and are not confusing. No enhancements of these panels were requirec. Other differences between Unit 1 and Unit 2 panels are summarized in the attached Table 2-1. From an operator's perspective, these two plants are to be operated identically, with the obvious exception of Unit 1 extraction steam. Enhancements and hierarchical labeling have been used to accentuate the minor differences. 2.1.4 Workspace and Environment 2.1.4.1 Workspace. A design review of overall workspace in the Midland control room was conducted on the mockup, in the pa tially completed control room, and using engineering drawings of the floor plan. Aspects of workspace that were addressed included: panel separation, accessibility, and specifically sigh' lines and reach distances. Of primary concern was the amount of workspace between the wall and back panels. This space is in compliance with HFE design criteria and appears to be adequate for all tasks performed in the walkthroughs. The proposed locations of desks and work areat are adequate. A lack of space on the benchboards to support procedures and writing materials is considered a deficiency, although common practice has accepted the use of carts or temporary arrangements for this purpose. Design discrepancies were revealed both for reach distance and visibility of components. The majority of these discrepan-cies occur on the front panel as a result of the relatively deep benchboard to which is affixed a 3-inch extended handrail. Over-all horizontal distance from the handrail to the vertical panel at shoulder height is 32 inches. The handrail itself contributes 3 inches to this distance. The result is that all reach distances to vertical panel and rear benchboard controls exceed l HFE design guidelines for the erect standing operator. To actuate them he must both rotate and bend his torso, a movement considered appropriate for low force, single hand or wrist manipulations. With the excessive distance, sight lines are also affected. Figures 2-2 through 2-5 illustrate anthropometric data based on 95 to 5 percentile male population. l 2.1.4.2 Environment. These areas can not be evaluated completely until control room construction is completed. (A list of items not addressed is presented in Table 2-2.) Human factors inputs will be used in completing workspace arrangement (i.e., procedure storage, e tc.) . A complete evaluation of workspace arrangement, environment, sound and lighting levels will be com-pleted prior to fuel load. l 2-4 l 1
TABLE 2-1. DIFFERENCES BETWEEN UNIT 1 AND UNIT 2 CONTROL PANELS
%s Panel Differences Note Safeguards-Front Announcing system gooseneck alke A on opposite sides of panel Primary-Front None Reactor-Front Unit 2 contains crossover steam compen- B sation control which is not on Unit 1 (mode 4 process steam)
Secondary-Front a. Announcing system gooseneck mike A on opposite sides of panel
- b. Unit I has second steam block valve B and two associated drain valves
- c. Unit I has only one vacuum indicator B
- d. Annunciator panel and CRT reversed A
- e. Annunciator panel over wrong panel D on Unit 1
- f. Aux Feed supply valve in different D location on Unit 1 Turbine-Front a. Annunciator panel and CRT reversed A
- b. EHC panels have only one L.P. B turbine on unit I
- c. Turbine section and generator A controls sections are reversed
- c. Annunciator panel over wrong panel D on Unit 1 Electric Additional breakers on Unit 1 for B process steam building g Post Accident None Safeguards-Back One group of non-IE indicators are on C opposite sides of the panel Primary-Back a. Quench Tank controls and Pump Seal B Recorders positions reversed
- b. A group of transmitter selector C switches are on opposite sides Reactor-Back None Secondary-Back a. A group of transmitter selector C switches are on opposite sides
- b. A group of circulating water pump C controls and indicators are on opposite sides
- c. Unit I has an additional valve for B extraction steam Turbine-Back a. Unit 2 has additional oil lift pumps B for second L.P. turbine Notes A. This difference is desired in that it pleCes the components in the location expected by the operator in relation to other panels.
- s. These are clearly identifiable as differences in configuration, or because their absence or presence has minimal or no significant operating tap 11 cations.
C. These differences occur on cack panels and are clearly identifiable on enhanced boards by group shape and color. Back puel controls and instru-ments are used in a more Os11 berate manner. D. These differences will be corrected prior to fuel load. I l 2-5 t_________________ - - - -- - - - -- -
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j Of5 PLAYS , i Ot$ PLAYS i I I i i WALL SACK PANELS FRONI PANILS Figure 2-5. Maximum Sight Angles t j 2-7
l TABI.E 2-2. ITEMS NOT ADDRESSED BY HFE DESIGN CHECKLISTS Due to the construction status of the control room the evaluation does not address the following: e Illumination Control room ambience Component illumination Reflectance factors e Atmosphere Heating Ventilating Air conditioning i e Noise Annoyance factors Masking of verbal communications Masking of auditory signals e Verbal communications Communications systems Implementation of systems e Emergency equipment Special hardware j Protective clothing e Portable furnishings - desks, chairs, tables, etc. l l 2-8
1 i 4 j () 2.2 PANEL LAYOUT AND INTEGRATION This section discusses overall functional relationships i between control panels and the integrative nature of operations. j In considering this aspect of the control room design, the most prominent design feature of the Midland plant is the front and I j back panel arrangement. The division of controls and indicators between front and back was determined early in the design and was i based on frequency and criticality of operation or monitoring. ! I ) Physically, from a center location on front panels to a center
! location on the back, a total distance of 44 feet must be
- travelled. During routine operations this may require an average j of 20 to 30 seconds to perform a single operation on a back i
panel. In general though, plant operation is intended to be controlled from the front with occasional brief excursions to the
, back for specific purposes.
J The following discusses functional / operational relation-ships between panels. (See rigure 2-1.) Section (2.3) discus-
< ses each panel separately. The Primary (2C12) and the Secondary
! (2Cll) are highly interactive because they represent the transfer j of energy from the reactor to the turbines. The Primary Panel is
- laid out with display groupings of like parameters (e.g., temper-i atures, pressures, levels, flows) not necessarily in logical i system functional arrangement. This panel primarily uses analog l indicators with only three analog recorders and three digital j readouts.
i f The Secondary Panel is generally laid out systematically and
- follows the flow of fluids from the condenser through pumps to
- the steam generator supplying steam to the turbine, and finally
] the production of electricity. This panel relies extensively j upon digital readouts (34) and analog indicators (18). i l' The steam generator is the connection between the two major systems represented on panels 2Cl2 and 2Cll, and is critical to total system operation. As a result of physical arrangement, this connection is not readily evident between the two panels, i particularly since the Reactor Panel 2Cl3 is located between l them. An integrated control system simultaneously controls the
- loading of the turbine generator, the steam generator, and the j reactor. Controls for the automatic system are split between the
{ Reactor Panel and the Secondary Panel. In a few situations, the j controls must be manipulated from one panel while responses are
- observed on the other. For example, steam generator feed is l controlled from the Secondary Panel but primary parameters i directly affected are located on the Primary Panel.
. Cooling systems for both plants and the common evaporator load for Dow Chemical are located on the Common Panel between i
l i l l 2-9 l
Unit 1 and Unit 2 main panels. Operations here can affect both ur. i ts . This panel is functionally grouped and has a functional philosophy of operation. It is an extension of the systems controlled by the Primary and Secondary panels but is physically separated. The panel also has a section that uses the engineered safety feature split screen status displays. The Safeguards Panel (2C14) includes indications and controls for emergency operations. Predominate to this panel are the Engineered Safety Features Actuation System (FSFAS) Status Displays. These displays use split screen status lights as an automated checklist. While monitoring Safeguards' displays, the operator must also relate to other panels in order to obtain systems information for problem diagnosis based on cues from these displays. A consistent design approach is used on all back panels. Each back panel is an extension of the associated front panel and contains less critical overflow indications and controls. These indicators and controls are arranged in small functional groups, that are somewhat randomly placed, making it difficult for operators to find specific controls and indications. Control of the electrical distribution system is provided on panel 2C15. This panel is systematically laid out employing mimic buses as an aid to the operator; it allows the operator to quickly diagnose problems and take appropriate follow-up action. Most of the information required to manipulate the electrical system is contained on this panel, so the operator does not have to refer to other panels. Although it is a good design, it does not specify key loads in the primary and secondary plants. Such specifications could aid the operator in determining the effect of the loss of a specific bus. The Post Accident Monitoring Panel (2C31) was added to the control room subsequent to the original panel design configur-ation. This panel contains safety grade controls and indications that backup normal controls on the main control panels. Since this panel came later, and is dedicated to emergency operation, its design is somewhat hybrid. It is functionally oriented as is l the Safeguards Panel (2C14), limiting its indications and con-trols to only critical functions that require close monitoring i after an accident has occurred. Yet, unlike the Safeguards Panel, it provides information that can be used to identify and diagnose problems. It must be noted that the panels provide for CRT displays. Since these displays have not been designed, they have not yet been evaluated. The capacity and capability of the computer system that drives the CRTs has been upgraded to allow improvements in the overall control room capability. 2-10
l i i () 2.3 PANEL / WORK STATION FINDINGS This section discusses review findings unique to l individual panels. The panels are discussed from left to right as l 1 they are faced from the front on Unit 2. Back panels are ; ! discussed with their respective front panel. l l 2.3.1 Safeguards (2C14) This panel is different from the Primary and Secondary Panels in that it is channelized with Channel A on the left and Channel B on the right. Both channels are essentially the same as evidenced by the panel appearances. The design philosophy is that automatic actuation vill take place when limiting parameters are reached, and the only operator action required, initially, is to be sure that all automatic actions have been accomplished. Automatic action, in some cases (emergency core cooling, for ) example), requires that certain systems be actuated or that a lineup change of systems that were in use for normal operation be made to support emergency operation. The design, therefore, provides an automatic checklist in the form of split screen status lights. This checklist feature was provided to meet the Bypassed and Inoperable status indication requirements of Regulatory Guide 1.47. When a particular type of emergency j actuation is initiated, the lights under that emergency section j are lighted to indicate that each step of the action is com-
- pleted. If a particular light fails to light, the operator can quickly note the exception and take action to have that step i accomplished. Thus, the panel provides a rapid automatic j response with a quick follow-up capability by the operator, i without any need to refer to procedures or to think through a j problem and consult drawings. Neither does the operator have to j rely on memory. The legends on these displays, however, are too difficult to read and terminology is confusing. Spare windows do
} not light upon system actuation, thus causing an interruption in
! the continuous amber "bar" of light. This will be a false alarm to the operator, causing him to think that a control did not g
operate, until he determines that the unlighted light is a spare. Just below the lighted split screen status display is a group of controllers that allow the operator to trip the emergency initiation if required. These actuators, however, must be located by name tag and are not spatially related to the emergency action status light section they initiate. This makes them difficult to locate in an emergency. l The remainder of the panel deals with follow-up operator actions that may be required. Such actions as changing certain critical lineups and throttling inputs may be required as an j tergency situation deteriorates or stabilizes. A few important O andications are available that are directly associated with follow-up operator actions. Since the panel exists the for l { 2-11 i s
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l 1 accomplishing specific emergency functions, only those lights, controls, and indications that require specific attention are present. The controls on the benchboard are not functionally grouped and appear to be randomly arranged. The right side of 2C14 is a duplication of the left side with a few minor variations in lights and controls. The addition of a valve control on the right that does not exist on the left disrupts the similarity of the two sides. Differences between the right and left side are not apparent without a detailed, control-by-control survey. The back panel has long rows of controls and digital indicators that are difficult to differentiate. There are 52 digital readouts on this back panel, along with many other miscellaneous controls. Throughout walkthroughs, operators were hampered by the reading of numerous labels while they searched for indications or controls referred to by the procedure. The right and left sides of the panel have generally duplicate systems, llowever, the left contains additional controls and indications not duplicated on the right. Although large general groupings are apparent, the relationships and arrangement within i the groups is not obvious and in some cases not functionally I logical. 2.3.2 Primary (2Cl2) Primary coolant indications are not arranged consistently with respect to function on the vertical section making it diffi-cult to relate the two sections. (i.e., They do not correspond to the appropriate controls on the benchboard.) In the top row, indicators are generally grouped by the parameters they present: levels to the left, then pressures, flows, and finally tempera-tures. In all there is a row of 21 indicators that look alike, eight of which have dual indications (e.g., loops A and B) . During walkthroughs, operators frequently confused one indication for another. Controls on 2Cl2 are in three large groups: pressurizer control to the right, makeup and letdown in the middle, and boric acid addition controls to the left. Within these groups, the relationship between controls is very hard to discern. As indi-cated previously, their arrangement does not correspond to the location of indications on the vertical section of the panel. Two computer driven analog trend recorders, each with three color pens are present on the panel. The information to be recorded for each of the six pens is selected on the computer control keyboard. Any parameters available in the computer will be available to these recorders for trending. A difficulty exists in the identification of what is being trended at any particular time. This is an interpretation issue for an operator who may think that a trend of interest to him is being displayed when actually a different trend is being displayed. Similarly, there could be confusion about which color to observe. 2-12
() All controls for the four reactor coolant pumps are on the back panel. (Note: An emergency shutdown pushbutton for stopping coolant pumps is located on the Safeguards Panel, immed- I lately adjacent and to the left of this panel.) l In addition to the reactor coolant pumps, other primary system components are present on the back. On the left side, the reactor coolant pump controls are arranged in columns, but the seal injection and return valves are not included in the columns under their respective pumps. Controls on the right hand side do not relate well to indications across the top. 2.3.3 Reactor (2C13) t This panel is functionally divided down the middle. On the
! left are the rod controls and indications; on the right are the reactor power indications. The various subsections of this panel i are well related to each other.
1 Rod control is performed at an integrated rod control panel. The functional relationships within this panel are intermixed for i no apparent reason. 1 ] The right side of the panel is functionally arranged but difficult to interpret. There are nine analog indicators across t O the top that appear alike, and nine digital them. indicators below I 4 Various set point controllers are located on the lower right of the benchboard section. Under the set point controllers are
- the ICS controllers. The back panei contains only four recorders that are clearly identifiable.
i 2.3.4 Secondary (2Cll Lef t) ! On the upper portion of this panel there are 22 digital indicators. These, together with nine analog indicators and a row of ten indicators, provide the indications of the condensate and feedwater system including auxiliary feedwater. Although these indications generally fall in a lef t-to-right system flow, i the continuity of readings is not obvious. The 16 indicators to i the right represent a combination of temperatures, pressures, and , flows for main feed. The left eight indications are related to I auxiliary feedwater and include turbine indications for one of the auxiliary feed pumps. There is no visible distinction between these groups. It will be difficult for an experienced o pe ra to r to monitor these indications and to diagnose problems. ! Even though there is some continuity of flow, albeit disjointed, it is difficult to differentiate these rows of digital indications. 2-13
The secondary plant controls on the benchboard cannot easily related to one another. Continuity of system flow is be ll difficult to follow and can be determined only by reading labels. A functional relationship between the controls and the indications is not apparent. The back panel (2C21) contains miscellaneous controls for the secondary system; these are not arranged systematically. The few displays across the top are not directly related to the controls under them except for the circulating water pump. 2.3.5 Turbine (2Cll Right) This side of 2C11 has some portions of the feedwater control and covers steam supply to the turbines as well as electric g ene ra to r controls. The turbine test panel and the turbine control panel are integrated control panels and are functionally well laid out. On the right side, electric generators and indications are functionally grouped. Generally, this side of the panel is arranged systematically and needs only minor enhancement to high-light subgrouping of functions. The back panel (2C21) is well laid out for the turbine generator section, but contains more niscellaneous controls for the steam system from 2C21 right, as previously discussed. 2.3.6 Common (OC10) Indications and controls on this panel are functionally grouped and generally systematically arranged. The two safe-l guards status displays are an extension of panel 2C14 but in this case the status lights are located immediately above the associated controls. Only the indications and controls on the upper middle portion of this panel are confusing in that their relationship to indications above and controls below is not apparent. The back panel (OC20) is similarly arranged in functional groups so that enhancements can be very effective. The arrange-ment of the groupings is not optimum from a functional perspec-tive. Thirty-four digital indications present the same difficulties that were discussed for previous panels, however, the functional groupings are better, and therefore more amenable to improvement by enhancements. 2.3.7 Electrical (2C15) This is the only panel originally designed with minics in the control room. The mimics greatly aid understanding of the complex electrical distributien system. Although the concept of' 2-14
t 4 ~ the. mimic is good, more effective minic techniques could enhance the use of this panel. In addition, some controls are not q-s connected to the mimic buses and therefore seem to float on their own. , The usefulness of this board will be improved if the plant i loads that are supplied from the breakers could be listed or categorized. This information will aid operator and trainees in
- learning the panel and aid in preventing errors under stress.
4 1 2.3.8 Post Accident (2C31) i j This panel was recently designed to incorporate Regulatory j Guide 1.97 indications and employs improved techniques such as functional demarcation lines with labels for each group. This l panel is channelized with Channel A indications on the left and i Channel B on the right. The upper position of this flat vertical l panel contains rows of vertical analog indicators. Along the j middle section are five multipen trend recorders. The lower portion contains several knob selectors. As configured, there is j little association between the analog indicators, trend recorders
- and controls. The operator must rely on labels of groupings as the only cue for identifying a functional group, and then j associating controls with indications. In addition, because it j contains controls that will be required during emergency oper-
; ations, its somewhat remote location requires coordination between operators.
This panel contains many spare indicators in the form of vertical analog gauges. Because of the many spares, the j operating gauges are more difficult to find. The search is
, complicated because percent (0 to 100) scales have been placed in j the spare (unused) gauges, making them appear operable.
2.4 ANNUNCIATORS
- There are 250 annunciator alarm locations for each unit with another 100 for common panels; approximately 10 percent are not used. All annunciator alarms use a horn for aural detection and i a white flashing light for visual detection; they use words or l' abbreviations plus an alarm number for interpretation. Annuncia-tors are arranged in matrices of 25 to 73 alarms per panel and are generally located on the panel to which they apply. There is one horn for each unit's front panel, one horn for the Common Panel, and one horn for each Post Accident Monitoring Panel, for
; a total of five horns.
- There are two overall concerns associated with annuncia-tors. In the overall response to alarms, it is difficult to
- determine priority of alarms by severity. A horn sounding and a flashing light might mean the beginning of a major abnormal
(~h transient or a minor anomoly in a remote board. The resction (,) required might be instantaneous response or a casual phone call , to an auxiliary operator. ! I i 1 2-15 l
1 l A second concern is in the location and arrangement of alarms. It is difficult to relate a particular flashing light to the front panel indications and controls associated with that alarm. Alarm arrangement within the Annunciator Panel does not aid this association. Annunciator Panel placement does not make direct association obvicus. All annunciator alarms are given the same visual / aural l priority. All are white tiles with black lettering; each of the l alarms is aurally announced with the same auditory signal. Thus, each demands the same attention. Yet the array of alarms varies from reactor trip and turbine trip to information indications that require no operator action. Window displays were found to use inconsistent and mislead-ing terminology, inconsistent font sizes and spacing. Some windows were difficult to read when the light was out. Often windows were overcrowded, further detracting from the read-ability. The annunciators have been designed to be used in conjunc-tion with the computer display to aid the operator in identifying plant conditions. Most windows are summary alarms or alerts, having several inputs. The operator can determine which par-ticular input condition caused the alarm by calling up the alarm display. It was judged, however, that there is sufficient infor-mation presented on the window to allow adequate follow-up by the operator if the computer should fail. 2.5 CONTROLS The major concern with controls centered upon the Integrated Control System (ICS) TT10 controllers. These are pushbutton controllers with an analog indicator, and are used to select manual or auto operation, and to control in manual. Twelve such units are used in the ICS, and eight more control key primary and secondary valves. As such, they are important to the func-tioning of automatic control systems. Human factors criteria indicated that these controllers are not optimally designed. The pushbuttons are smaller than desir-able and are located adjacent to each other with no space or barrier between them. Some initial objections were caused by a lack of understanding by operators of how the controllers were implemented in the system. These controllers were consequently subjected to extensive evaluation in each stage of the review process. Extensively used through the control rooms, J-handle switches did not meet the human factors criteria for length of handle. Nevertheless, the low-torque design of the switch was considered to be satisfactory, therefore the handles were consid-ered adequate. 2-16
f a l Similarly, knob selector switches were smaller than i recommended by the criteria. These too were considered adequate because they could be manipulated without difficulty. t ! Pushbuttons for operating the annunciators used a mushroom-l ' shaped palm-actuated handle for acknowledgement, reset, and test. These were spaced too close together for palm actuation and could j lead to misoperation when the operator reached quickly to silence i an alarm. i 2.6 DISPLAYS Visual displays are primarily of two types: vertical analog l indicators and digital LED readouts. Major concern was centered on the RY series of indicators. Used extensively on the panels d for non-IE indication, these indicators had many discrepancies. In summary, the discrepancies included pointer design and place-ment, graticule arrangement, scales consistency, extensive use o f scale multipliers, and mid-scale failure. These indicators were subjected to extensive evaluation. Vertical indicators pro-vided by other suppliers generally conformed to human factors
- criteria.
Extensive use of digital LED indicators raised concerns about the ability of an operator under stress to gain qualitative information. During rapid system changes the operator must study the meter to determine direction and rate of movement. The task i l O' analysis, however, verified that digital indicators were generally not used to determine rate and direction information ] during high stress transients. 1 Status displays on the Safeguards Panel and on the Common Panel use legend light indicators. These indicators are small i and have excessive wording that is non-standard and inadequate in font, size, and overall readability. j 2.7 LABELS The panel labels consist of white alphanumerics engraved on a black plastic plate. In general, the alphanumerics were non-standard in font, size, terminology, abbreviations, and place-ment. Labels included numbers as well as names, making them l difficult to read. In many situations observed, operators had difficulty in finding components on the panels because of the difficulty of reading labels. Labels on indicators tended not to be consolidated for easy reading. Some required the operator to look in three different places to find the information needed in reading a meter. Hierarchical labeling was not generally used. There was no standardized list of operational terms and abbreviations. Names were taken from engineering drawings and were frequently l 1 O' difficult to interpret when not read in a system drawing context. 2-17
Frequent use of acronyms throughout the panels made understanding h difficult and encouraged their use in oral communications, resulting in potential confusion due to their similar sounds when spoken. 2.8 PROCESS COMPUTER The original process computer is being replaced by an advanced design system with built-in backup capability and advanced graphic capability. The computer system is powered from a reliable battery-backed power source. The installed computer system is currently undergoing acceptance testing, and is not yet available for review in the operating mode. System documentation, particularly the software program for the man-machine interface, has been reviewed. Operational displays, specifically designed to aid the operator in performing normal and emergency operations are, however, still in the design process. Human factors inputs and recommendations have been maje during the design process. The SPDS displays are being designed by the NSSS vendor and are not yet available for a human factors review. The full system will be reviewed when the computer system is operating and available, and the display designs are completed. 2.9 COMMUNICATIONS The state of construction of the control room and plant did not allow the team to review the adequacy of the communications systems. This system will be reviewed and assessed when available, prior to fuel load. 2-18
)
l Section 3 IMPLEMENTATION j This section discusses modifications to be made to the l control room to improve the man-machine interface. These modifi- , cations are based on the CRDR evaluation team's assessment of the ! HEDs. If taken on an individual basis, it is difficult to ascertain that any one discrepancy would have a significant safety impact. However, when taken as a group, the number of discrepancies takes on added significance, therefore, the intent of the team was to resolve as many discrepancies 'as possible, including those which if taken alone would appear to have minimal impact on safety. The modifications to be implemented are discussed in the following categories: e Overall Panel Improvements e Controls e Displays e Dedicated Panels Appendix A includes all HEDs categorized as listed above. This appendix contains justification for those HEDs that, on further evaluation, were considered acceptable. The final subsection discusses scheduling of the remaining review items, and further discusses the schedule for resolution of items still under evaluation. 3.1 OVERALL PANEL IMPROVEMENTS This section discusses those panel improvements to be imple-mented on main control panels and the auxiliary shutdown panels. 3.1.1 Control Panel Enhancements The analysis of HEDs resulting from the control room survey indicated that the majority of discrepancies were in the area of functional grouping and labeling of components, which could be corrected with control panel enhancements. To ensure that the overall panel enhancements would be designed for improved o pe ra to r performance, some fundamental decisions were- reached initially. First, it was decided to establish an accepted operational description of the plant. A large simplified plant diagram was used describing plant systems and O systems in i components, and was used continually during review team discussions to ensure complete team agreement and understanding 3-1
f 1 l of system terminology and system boundaries. The second decision was to determine who in the operational population (level of expertise) the enhancements would be designed to support. The final choice was the licensed auxiliary operator, as he would have had minimal operating experience on the panels. With agreement on these two basic issues, a general philosophy of enhancements was arrived at. Enhancements would: e Show functional grouping of components e Utilize mimics where they provide useful information to the operator o Employ hierarchical labeling
- Meet accepted human engineering practice With the above criteria as " ground rules," the review team proceeded to evaluate various control panel enhancement techniques. It became quickly evident that the criteria could not be met if all components were to remain in existing l locations. Therefore, a technique that involved the swapping of like components was developed to facilitate improved functional I grouping. The decision on swapping components would be based on:
e Maintaining functional group relationships e Providing aid in mimicing e Providing correct sequence of operations 1 i The first panel to be enhanced was the Primary Panel (2Cl2). l An enhancement design of this panel was prepared using conven-tional outlining of components to achieve functional grouping. By virtue of the limitations on swapping, and the layout of the vertical panel and benchboard, the functional groupings obtained were large and irregularly shaped. These groupings were l considered unacceptable, as it was easy to become lost within the l functional group. Next, the use of color shading of functional groups was evaluated. This method was considered acceptacle, as it indicated the relationship between related groups on the vertical section with groups on the benchboard section, even if these groups were not physically contiguous. Use of color shaping on the green panels was, however, considered unaccept-able; a decision was made to paint the control panels beige to obtain a neutral background for the color enhancements. When developing the criteria for color coding, some con-straints had to be considered. These constraints were: the absolute limit of the numbers of colors; the maintenance of accepted industry color conventions; and the availability of CRT color graphics. 3-2
O The criteria for color coding when used as a memory aid was as follows: I e Associated with colors will be other cues that specify meanings, so that color need not be completely defini-tive. This means, more specific identification will be used. As an example, the shape of the grouping and the grouping labels will provide cues in addition to color to aid in identification of functions. e Colors will be chosen such that they imply meaning. For example: red = ho t; blue = cooler; magenta = radio-active. But these will not be definitive. Where physi-cal separation and functional differences exist, the same color may have a different meaning provided no confusion will result. Examples might be: red = steam on the secondary panel; red = high voltage bus on the electrical panel. e only defined color codes apply to controller-indicator lights. The Midland plant convention (which is also an industry standard) is as follows: red = breaker closed, motor on, valve or damper open, start, increase (flowing)
,O
\m) - green = breaker open, motor off, valve or damper closed, stop, trip, decrease (not flowing)
- amber = breaker tripped, remote, overload or abnormal condition white = breaker condition, normal permissive or limit position or condition reached Following the selection of the enhancement technique to be used, enhancements were designed for each control panel and implemented on the full-scale mockup of the Unit 2 control room.
Operational personnel were formally and informally involved in reviewing and commenting on enhancements as they were imple-mented. When the mockup was completely enhanced, a formalized i validation was conducted as part of the Validation of Control l Room Functions described in Section 1.4.6 of this report. Subse-l quent to the validation, minor upgrades were made to the mockup. The final aspect was to formally document the enhancements. l This was accomplished by generating a complete set of drawings ! specifying functional grouping shapes, associated colors, demar-l cation lines, mimics, and labels. These drawings provided the l basis from which panel enhancements will be implemented on the l s actual control room panels. l 3-3 l . _ _ -
[ l Examples of control panel enhancements to be implemented are shown in Figures 3-1 through 3-4. These figures show before and after enhancement photographs of various cer.Lrol panels as im-plemented on the control room mockup. In order to arrive at the final panel configuration, approximately 125 components per unit will be swapped and/or relocated on the control panels. 3.1.2 Panel Labeling In conjunction with the effort to enhance the control panels, as discussed in Section 3.1.1, a hierarchical labeling concept was implemented to improve the readability of labels. Prior to determining the specific label contents for individual components, a list of standardized terminology and abbreviations was developed for use in selecting label content. Additionally, a label font specification was developed, and a decision was made to provide black letters on a white background for all labels. The new labeling scheme was implemented on the mockup as other enhancements were added. This allowed operational review of the labels during the review of other enhancements. 3.2 CONTROLS 3.2.1 Reach Distance Due to the depth of the benchboard section of the control h panels, operation of several controls require torso flexion and rotation. To minimize the reach distance to these controls, the protective rail on the front of the contro) panels will be removed. Removal of this railing will reduce the reach distance by 3 inches. 3.2.2 TT-10 Controller These controllers contain an analog indicator that can display either of two values dependent on the position of a toggle switch. The toggle switch positions are labeled POS/DEV; however, the analog indicator on different control stations can display different values in either position, depending on how the particular control station was wired. To better indicate the value being displayed on the analog indicator, the POS/D EV i position will be relabeled to better indicate the parameter being displayed with the toggle switch in a given position. 3.2.3 Pushbuttons Pushbuttons controls utilized to perform various functions throughout the control room do not have a consistent color coding 9 l l 3-4
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O- Figure 3-4. Safeguards Panel (Back) 2C24 Before and After Enhancements 3-11
g' indicating their function. As part of the overall panel enhance-ment process, the pushbuttons will be modified in color to conform to the following conventions. FUNCTION COLOR Emergency Trip Initiation / START Red Block Orange Bypass Yellow Alarm Acknowledge Yellow Reset White Stop Green Test Black 3.3 DISPLAYS 3.3.1 Safety Parameter Display System (SPDS) /CRT Displays
, In order to integrate plant parameters so as to enhance the operator's and supervisor's ability to comprehend plant condi- \- tions, an SPDS will be provided. The SPDS will consist of CRT displays that provide the operator with information regarding the current state of the reactor coolant system and the status of other important safety parameters. The displays will consist primarily of pressure-temperature curves upon which appropriate operating constraints are superimposed. The displays are being designed to support the ATOG in providing integration between the SPDS and plant EOPs.
Other CRT displays that would support the operator in per-forming routine plant evolutions are also being provided. These displays would consist of schematic diagrams of plant systems or other display types such as bar charts or trend graphs that would aid the operator in performing specific tasks. As these displays are provided for normal plant operations, they would have no safety significance and would be subject to change as operating experience on the plant is gained. 3.3.2 Annunciators 3.3.2.1 Annunciator Windows. A brief description of the dis-crepancies noted in the review of the annunciator system was l provided in Section 2.4. In order to improve the annunciator l system, a revised design of window arrangements for each annun-l l [d
\ ciator matrix will be provided. This arrangement groups alarms 3-13
l logically and better relates them to the control panels under I them. In designing the groupings, the higher priority alarms l were generally placed at the top of the matrix and lower priori-ties at the bo ttom. l A standard method was selected far denoting priorities, l using red windows for the highest priority, yellow for inter- i mediate priority, and white for low priority alarms. To simplify window interpretation, all windows will be renamed using standard terminology and abbreviations. In designating window names, terminology was chosen to reduce the number of words needed while better identifying the function that is alarming. All windows will use standard font and size specifications that meet viewing distance and readability requirements. 3.3.2.2 Annunciator Pushbuttons. The pushbuttons for responding to annunciator alarms uses mushroom-shaped palm-actuated handles for acknowledgement, reset, and test. These pushbuttons were spaced too close together and could result in an operator hitting the wrong button when attempting to silence an alarm. Addition-ally, the colors of the pushbuttons did not corresponc to control room conventions. To alleviate these discrepancies, pushbutton color will be changed to conform with the standard control room pushbutton color code. In addition, to prevent depressing the wrong button when acknowledging an alarm, the acknowledge control will be retained as a mushroom-type palm-actuated control, but the reset and test controls will be changed to finger operated pushbuttons, and the test button will have a raised guard. This will allow rapid accurate operation by touch. 3.3.3 Vertical Indicators (RY1200/RY2200) These vertical display indicators fail mid-scale. To im-prove the ability of the operator to determine that these indica-tors have failed, alarms have been provided in the control room to indicate failure of the power supply powering these indica-tors. Additionally, the mid-scale point on these indicators will be marked in red to alert the operator to check other indications when the meter is steady at mid-scale. 3.3.4 Vertical Indicators (SIGMA) These indicators are dual range and are used extensively in safety systems. In some cases, these indicators are installed in I the panel when neither side is used. For such cases, these spare l indicators will be removed from the panel. In other cases, one l Side of the dual range indicator is used and the other side is i spare. These spare indications, however, have range scale markings that make it appear as if they are active meters. To alleviate this problem, the range scale markings on these spare indicators will be deleted or marked in a manner to clearly indicate that they are spare. 3-14
l 3.3.5 Digital Indicators { There are two digital indicators, utilized in the control a room, that at various times during plant operation are operated outside of their normal indicating range. The reactor average coolant temperature indication has a range of 520 to 620 F and i thus will indicate 520 F even with the plant at cold conditions. l There is a low range pressurizer pressure indication that has a i range of 0 to 600 psig. This indicator will continue to indicate
- 600 psig during normal operating conditions. Methods of blanking these displays while simultaneously indicating to the operator that these displays are still active are being evaluated.
j 3.3.6 Condenser vacuum Indication ! The indication of condenser vacuum is provided in PSIA.
- Operators are more familiar with units of "IN" of Hga, and the i turbine manufacturer uses these units in describing limits on the j turbine. Therefore, the control room indications will be changed to read in "IN" of Hga to match operator expectations.
{ 1 ] 3.4 DEDICATED COMPONENTS 1 3.4.1 Safeguards Split Screen Status Indicators i These indicators are used to display the status of compo-nents actuated by the Engineered Safety Features Actuation System. The concept is that there are two rows of lights that indicate the status of these components. The top row of white lights indicates that the components are capable of being ac-tuated (i.e., control power available, breaker racked in, etc.). 4 Lights in the lower row are utilized to indicate that these components are in their actuated conditions. The operator reads this display by exception, in that during normal operation all white lights should be energized in a continuous bar; and, , following actuation of the Engineered Safety Features, all amber lights should be energized in a continuous bar. There are, however, spare windows on these displays that interrupt the continuous light bars. These interruptions would tend to confuse the operator, especially following safety system actuation. Additional concerns with this display system were that legends
- and fonts on the lights were not consistent, and the content on the windows was crowded and difficult to read.
To improve this display, unused windows will have the white and amber lights energized so that the light " bars" will be continuous upon system actuation. Legends will be changed to be consistent with legends on the control panels. Hierarchical labeling and demarcations will be used to aid the operator in reading individual windcws by e xc e p-l tion in order to take follow-up action. 1 l 3-15
l 3.4.2 Core Map h The Reactor Panel contains a core map that is used to dis-play the status of the control rods within the core (full out, full in, en control, misalign). Each rod is numbered to be used in conjunction with a digital indicator that indicates the posi-tion of each control rod, one rod at a time. This display is used following a reactor trip to verify that all rods are on the bottom. The axial power shaping rods do not drop in following a reactor trip, but the core map display does not indicate which rods are located in which group. Additionally, as only one rod position can be displayed at a time, there is no method of veri-fying that all rods in a group are tracking as desired when starting up the plant. To alleviate these problems, a core map overlay will be provided. This overlay will indicate the rod group arrangement and the number of each rod within the group. Additionally, a CRT display will be provided to allow collective tracking of the control rods' individual positionL while starting up. Providing the CRT display will require minor modification to the method utilized to input control rod drive positions to the plant computer. 3.4.3 Rod Control Panel The functions and operational relationships on this panel are not optimally arranged and could confuse operators. Rod motion terminology is up to withdraw, down to insert. The i n-o ut joy stick control is located on the slanted benchboard. The control must be pulled toward the operator to withdraw rods, and pushed away to insert the rods. This is opposite to the sense of the board where toward the operator is down, away from the oper-ator is up. Another concern is the inconsistency in the color of indicating lights with respect to overall control room conven-tions. This panel is used during routine operation (i.e., startup) only. There is no stress associated with operation of this panel. The in-out joy stick control is clearly labeled. Discus-sions with operators indicate no significant operational conse-quences since the withdraw direction is a pulling motion, consis- , tent with the terminology of ' pulling' rods. The panel design l was considered acceptable with the exception that panel i nd ica t-ing light colors will be changed to conform to control room standards. 3.4.4 Main Steam Line Isolation Valve (MSIV) Operating Panel This panel is used to operate and test the MSIV from the control room. The lights on this panel are excessively large and bright. The brightness of the indicator lights is distracting, 3-16
I 4 r i O N/ while the size of the lights obscures labels. human factors characteristics of this operating panel, it will be To improve the ! l modified to reduce light intensity, make labels easier to read, ! and change lens covers to conform with control room standards. 3.4.5 Emergency Core Cooling Conditioning Cabinet f This cabinet contains the controls necessary to restore , components actuated by the emergency core cooling actuation r system to manual control following automatic actuation. The labels on the controls indicate only the component identification number and do not indicate sufficient information to the operator - as to the exact component being controlled. To improve this i panel, the controls will be relabeled to better indicate what l components are affected by each. [ 3.4.6 Feed Only Good Generator (FOGG) Bypass Switches i During plant cooldown with an isolated steam generator due l to a ruptured tube, the differential pressure between steam I generators will exceed 40 lbs. This will actuate FOGG, which [ will allow feeding only one generator, blocking the other. There ' will be times in the cooldown when both steam generators must be l fed. Although FOGG bypass switches are provided, the operations ' required are confusing and could be misapplied during stress , situations. To correct this discrepancy, switches that bypass ' (s FOGG will be modified to allow simultaneous feeding of both steam generators. i i 3.4.7 Main Steam Line Isolation (MSLIS) Bypass [ i During cooldown with a ruptured steam generator tube, there t is no provision for bypassing MSLIS with the bad steam generator l still at an elevated pressure. In order to prevent MSLIS actua- ;
! tion during plant cooldown both steam generators cannot be within !
l this window. Actuation of MSLIS isolates the steam generator and j l interrupts the cooldown. [ The MSLIS bypass logic will be redesigned to allow the bypass to be put into effect with only one steam generator less f than 725 psig. The bypass will be automatically removed if the j 4 pressure in both steam generators exceeds 725 psig. ! 4 l 3.4.8 Power Operated Relief Valve (PORV) Maintain Contact f The PORV switch on the Post Accident Monitoring Panel (2C31) i , is a spring return-to-close switch. During certain emergency l operations the PORV must be open for long periods of time to : maintain core cooling. Due to the spring return switch, an ! operator must hold the knob selector switch in the open position, j ( To correct this discrepancy, the PORV control will be changed to a maintain contact switch and alarms will be provided ; to indicate that the PORV switch is not in the AUTO position. ! i ' 3-17 i
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1 l l l I 3.4.9 Emergency Core Cooling Enable to Sump Recirculation g After the emergency core cooling system has actuated, certain actuated components cannot be restored to manual control without simultaneously resetting other safeguards systems. The automatic switchover of the safeguards that pumps suction from the BWST to the containment sump is actuated on low BWST level, in conjunction with an emergency core cooling actuation signal (ECCAS) . The ECCAS input to the automatic switchover logic would be removed if other safeguards components must be restored to manual control, as restoring these components to manual also resets the ECCAS enable to the switchover circuitry. In order to correct this situation, the ECCAS enable input to the automatic switchover logic will be located individually on an AUTO / MANUAL override switch. This will allow other components to be restored to manual without resetting the ECCAS input to the switchover logic. 3.4.10 Steam Generator operate Range Level Steam generator operating range level is provided only on back panel 2C21. This is the only temperature compensated level available to operators. This indication is frequently referenced during both normal operations and emergency conditions. Steam generator operating range level indication will be relocated to the front of the Secondary Panel (2Cll) replacing the steam generator wide range level currently on the front panel. Additionally, making this indication a recording type display is being evaluated. Locating a recorder on the front panel may not be feasible due to space constraints behind the panel. 3.4.11 Main Feed Flow Recorders During transient upsets of the secondary system, the most appropriate operator response is to assume manual control of the feedwater system and attempt to stabilize feed flow to both steam generators. Trend recorders would be useful to the operator in performing this evolution. Locating a trend recorder on the front panel is currently being evaluated. Due to space con-straints, however, locating these recorders in the required loca-tion may not be feasible due to space constraints behind the panel. 3.4.12 Emergency Boron System (EBS) Tank Level EBS tank level indication is provided on the Post Accident Monitoring Panel (2C31), while the makeup pumps that take suction from these tanks are controlled from the Primary Panel (2Cl2). With low level in the EES tank, the makeup pumps could poten-tially be damaged due to a loss of suction head as the indication is too far removed from the pump controls. The EBS tank level indication will be relocated to be closer to the pump controls. 3-18
4 3.5 SCHEDULING Actual implementation of improvements described above has . commenced but is still in the engineering stages. CPCo is making i their best effort to complete implementation of all items identi-fled above by fuel load on each unit. In the event that we
- become aware that implementation of any of these modifications cannot be completed by fuel load, a report will be provided describing the reason for this delay and identifying the new schedule.
Section 2.1.3 indicates that certain workspace and environ-mental aspects of the DCRDR had not been completed due to the
- construction status of the control room. These items were speci-
! fically identified in Table 2.2. Those items identified will be completed when the control room is completed, or as construction status allows. The results of that review will be documented and submitted as a follow-up report to this document. It is antici- ! pated that submittal will occur approximately 6 months prior to j scheduled fuel load. At the time of this writing, two items do not have defini-tive resolution. These items are: { { e Digital Indicators: Some indicators remain active when the parameter they display is outside the indicator's j w range. These indicators should have some means for indi-cating that they a re ' o f f-scale ' . 1 e Steam Generator Level and Feedwater Flow Indication / l Recorder: Trend recording of recent level history and 4 feed flow is useful to the operators during both normal
! and emergency conditions. Relocation of steam generator level and main feed flow recorders to the front of the i Secondary Panel (2Cll) is planned. As a result of space constraints, investigation is ongoing to determine the
] most appropriate approach and size of recorders. l As indicated above, these items are still being investigated and evaluated as to the feasibility and method for implementa-tion. When these items are resolved, the results will also be
- documented in the follow-up report to this document.
i I I I 4 , v 3-19
1 i i j i i i I t i i AFPendix A l
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HUMAN ENGINEERING DISCREPANCIES h I i l l 1 1- - - - - - - - _ _ . - . _ _ _ _ _ . _ , . , _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ .
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i I l i I i i I I v r I
)
i i f OVERALL PANEL IMPROVEMENTS i i I, i b l 'l I i J l i i I l r l 1
)
- 1. !
1 ! } () HUMAN ENGINEERING DISCREPANCY E-010
- COMMENT:
4 s i J Functional Relationships: Sets of indications and controls l related to the same function are not well related to one j another on the panels. l i l LOCATION: h i ! 2C14/24, 2C12/22, 2Cl3, 2C11/21, OC10/20 i J j DESCRIPTION: 1 1 l Indications and controls related to a particular function are } not grouped together and are difficult to relate to one j another. i 1 i l 4 i j l RESOLUTION: i
- Swap components as required and enhance.
{ 1 I i I ! I l A-1 1 ! _ ___ _ - - _ _ _ _ _ _ _ _ _ __ _ _ _ _ . . . _ _ _ -. . _ . . . . _ . _ _ _ _ _ _ , _ . . - . . ~ .
HUMAN ENGINEERING DISCREPANCY E-Cll l l COMMENT: Functional Grouping: Controls and displays are not set off visually and identified as functional groups or in systems relationships. LOCATION: 2Clt./24, 2Cl2/22, 2Cl3, 2Cll/21, OC10/20 DESCRIPTION: Both displays and controls are identified only by individual name tags and are not subdivided and labelled as functional or systematic sets. RESOLUTION: Swap components as required and enhance. l l 9 A-2
l 1 i i 4 j HUMAN ENGINEERING DISCREPANCY C-001 3 i i i COMMENT: i Panel Controls and Indications: Arrangements within functional or systematic sets are not optimum for sequence of operation or comparison of readings. 1 I j LOCATION: i 2C14/24, 2Cl2/22, 2Cl3, 2Cll/21, OC10/20 i a DESCRIPTION: () Meters and controls within sets are not arranged in an order l that aids identification and interpretation or operation. j Rows of meters and controls that look alike and are not j optimally arranged are difficult to differentiate without ! closely inspecting name tags, t l 4 i l i RESOLUTION: i e Swap components as required and enhance. i J A-3 4
- . - - , - - - - - , - , n
HUMAN ENGINEERING DISCREPANCY D-002 COMMENT: Back Panel Controls: .Many indications and controls are located on the back of operating panels. LOCATION: 2C24, 2C22, 2C223, 2C21, OC20 DESCRIPTION: Indications and controls on these panels are not visible to the operator from the front panels. When an operator goes to the back panels, he cannot be seen or talked to directly by the supervisor. Some operations require coordinated operations between f ront and back. RESOLUTION: Task analyses and walkthroughs substantiated that most operations on the back panels are discrete actions. One operator will remain on the front panels while the other goes behind for a specific task that can be completed quickly and then return to the front. A communications system between front and back will be provided. O A-4
i HUMAN ENGINEERING DISCREPANCY T-003 i i
- COMMENT
, i I
Separation of Primary and Secondary Panels. i I j j i [ LOCATION: Panels 2Cl2 (primary) and panel 2CllL. j i
- DESCRIPTION
i ] The panel used for controlling primary system- parameters a (~)/ (_ (2Cl2) and the panel controlling feedwater ( 2CllL) are
; separated by panel 2Cl3 such that regulation of these directly interacting systems require switching from panel to panel or ! using two operations simulataneously.
I i 1 RESOLUTION: 1 I i
- There will be two operators for each unit. One will be the j primary operator, the other the secondary operator. In i addition, operators will be trained in team coordination for 4
plant operations. Relocation of the Primary and Reactor panel
- . Would interfere with the required interfaces between the
! Primary and Safeguards panel.
l l !O 4 l j l A-5 f
HUMAN ENGINEERING DISCREPANCY P-005 1 l COMMENT: Panel Lens Color: Red, green, and amber lenses are transparent making the filament visible. The white lens is translucent making it appear somewhat dimmer but larger. The overall effect on detection and interpretation is similar for all colors. White Indicators: There is difficulty in distinguishing between white and amber indicators beyond 120 inches, particularly at angles of incidence in excess of 45 degrees. LOCATION: 2C14/24, 2Cl2/22, 2Cll/21, OC10/20, 2C15, 2C31 DESCRIPTION: Indicator Lights - General Electric, GT-ET, green, red, white, amber. RESOLUTION: Amber lights are not utilized for alarm detection. If the amber lights do indicate an alarm condition, this condition is - indicated through the annunciator system. Operational requirements to distinguish amber from white lights beyond 120 inches at viewing angles in excess of 45 degrees cioes not exist. O A-6
I 1 HUMAN ENGINEERING DISCREPANCY O-001 C 1 i
- COMMENT
- l i
i Communication System: Communications between front and back i panels and between the control room and auxiliary spaces may i not be adequate. i ) LOCATION: i .i Control room and auxiliary spaces. J 4 i DESCRIPTION: I i ! The only communication system available for use within the
! control room is sound-powered plug-in jacks. These may not be i flexible enough for communications between front and back j panels and between panels and auxiliary operators.
1 I i ) i RESOLUTION: 1 4 I i control room communications will be evaluated further j following manning of the control room. 1 I ~ l 1 5 1 A-7 .i I
HUMAN ENGINEERING DISCREPANCY E-036 COMMENT: Safeguards Controls: Not grouped by functions or systems. 1 j LOCATION: 2 C i t. DESCRIPTION: Controls associated with the several safeguards systems, located beneath Safeguards Panels on both the vertical and benchboard sections, are not grouped by system or functions. 1 i RESOLUTION: i Enllance to show functional relationships. O A-8
HUMAN ENGINEERING DISCREPANCY T-005 COMMENT: Control Room Telephones: Many telephones planned for installation in the control room can cause an overload on the operating team during emergencies. LOCATION: Control Room Central Desk. DESCRIPTION: O Current plans include the installation of many telephones in the control room in order to allow the rapid notification of officials and agencies of site and general emergencies. The team plan requires all control room shift personnel to fill vital operational roles that may not allow time to make phone calls or to answer phones. A method for handling communica-
- tions must be devised.
RESOLUTION: In accordance with plant administrative procedures, if it becomes necessary to use these telephones, a knowledgeable and trained shift person from outside the control room will be called in to act as communicator. O A-9
l HUMAN ENGINEERING DISCREPANCY E-032 COMMENT: Safeguard Panel: Not adequately labeled. LOCATION: 2C14, OC10L DESCRIPTION: The entire Safeguards panel is not identified through label-ing. The complete name should be written out unless operators are more familiar with acronym. RESOLUTION: The panel and each actuation system will be labeled with functional names. O A-10
i i j . HUMAN ENGINEERING DISCREPANCY E-Cl2 1 3 l COMMENT: ? 4 Redundant Controls: The Safeguards panel is channelized for reliability. The sets of lights and controls have some differ-ences that are not evident. l 1 4 } LOCATION: 4 2C14/24 DESCRIPTION: ) i g he lighted actuations for some safeguards functions have i ' minor differences between the two channels. These differences 2 are not indicated and cannot be detected without a light-by-I light survey. There are extra controls on one side that are
- not duplicated on the other, nor are they highlighted.
1 1 1 1 1 i l l RESOLUTION: 1 i i Enhance to make differences clear. i 1 i i k i ) A-11 4 i
- - - . .~ . . . , . .
l HUMAN ENGINEERING DISCREPANCY C-0C4 COMMENT: Post Accident Fonitoring Panel: Some meters, recorders, and controls are not arranged in the best functional groupings. LOCATION: 2C31 DESCRIPTION: Although arranged in groupings, the relationship between the meters in the upper portion to recorders and controls below is not obvious. With the addition of new controls, the groupings have become disjointed. Many spare indicators containing percentage scales complicate the functional grouping. RESOLUTION: Spare indicators will be removed or scale face will be covered to indicate which meters are not active. Indications and controls will be swapped and enhanced to improve functional grouping. O A-12
l ( ) ! i i 1 HUMAN ENGINEERING DISCREPANCY E-009
)
l 1 i i COMMENT: i l l Electric Panels: Mimic conceptually incorrect. l l I i i i J ), LOCATION: i l 2C15 ) ! DESCRIPTION: i i l Mimic arrows pointing toward 1A01 and 1A02 should be reversed. 1 1 l 1 j RESOLUTION: l ! The mimics for this panel will be redesigned to show the ! proper relationship. l i A-13
HUMAN ENGINEERING DISCREPANCY E-CCS l COMMENT: I Electric Panel Loads: Panel does not identify loads associated with distribution buses. LOCATION: 2C15 DESCRIPTION: The panel is well laid out as a mimic bus, but the consistency of labeling and terminology is less than optimum. RESOLUTION: The panel will be enhanced to show major loads and categories of minor loads. l A-14
} l t ! HUMAN ENGINEERING DISCREPANCY E-S13 I i I i i j COMMENT: i i 1
- Label Formats.
1 i t 1 i i \ i LOCATION: I e Throughout control room. DESCRIPTION: The inclusion of numbers to identify pumps, tanks, valves, etc., on the top of labels sometimes interfered or slowed the search for item locations. . i l l RESOLUTION: 1 5 d Standardize label design. l t } i 3 l 1 1 i l l A-15 1
HUMAN ENGINEERING DISCREPANCY E-014 COMMENT: Legend Inconsistency: Legends are not standardized throughout control room. LOCATION: 2C14/24, 2Cl2/22, 2Cll/21, CC10/20, 2C15, 2C31 DESCRIPTION: There is inconsistency of (1) spacing between label and component, (2) location of label relative to component, (3) size of label, and (4) character height and font. 1 RESOLUTION: Use standard labeling. O A-16
r HUMAN ENGINEERING DISCREPANCY E-015 (} C?MMENT: Control Lights: Inconsistent labeling. LOCATION: 2C14/24, 2Cl2/22, 2C11/21, OC10/20, 2C15, 2C31 DESCRIPTION: O Indicator Lights - General Electric, GT-ET, green, red, white, amber. A legend is provided for the indicator light when the neaning of its "on" state is not otherwise obvious. This legend is on a nameplate inconsistently affixed either to the right or above the component. Indicator lights within component sets, where their meaning is obvious, have no legend. Where indicator lights stand alone, two nameplates may be affixed, one a label identifying the component function and the other a legend identifying the "on" state. On some indicator light nameplates, this information is combined. There is a general inconsistency of identification. RESOLUTION: Use standard labeling. O 1 A-17
HUMAN ENGINEERING DISCREPANCY E-016 COMMENT: Synchroscope Lamp: There is no label for this component. LOCATION: 2CllE DESCRIPTION: Indicator Light i RESOLUTION: Component has been labeled. O A-18
I HUMAN ENGINEERING DISCREPANCY 2
'-110 Os 1 COMMENT:
Tap Changer Legend: Character size is inadequate for the required viewing distance and font styles vary between Vendors. LOCATION: 1 2C15 i DESCRIPTION: J-Handle Selector - General Electric, tap changer. O Westinghouse, tap changer. RESOLUTION: Since tap changers are used for infrequent, minor adjustments, during normal operation, and not at all during emergency operations, their operation is deliberate with no stress. Scales on these meters are easily readable for the function l they must perform. These meters are not the primary feedback I for tap changer position. O A-19
)
HUMAN ENGINEERING DISCREPANCY E-109 COMMENT: Ceneral Electric Breaker Switch: Legend character size is inadequate for the required viewing distance. LOCATION: 2C15 DESCRIPT!7N: J-Handle Selector - General Electric, synchronizing breaker (2C15). RESOLUTION: Task analysis indicated that operation of these switch / lights is limited to their immediate location, therefore viewing distance is adequate. O A-20
l l i i l l l HUMAN ENGINEERING DISCREPANCY E-126 h O COMMENT: General Electric Switch Legends: Character size is inadequate for the required viewing distance. LOCATION: 2C14, 2Cl2, 2C11/21, OC1cL DESCRIPTION: J-!!andle Selectors - General Electric, pointer type. O RESOLUTION-l l Task analysis indicated that operation of these switch / lights j is limited to their immediate location, therefore viewing i distance is adequate. I O A-21
HUMAN ENGINEERING DISCREPANCY E-101 COMMENT: Knob Selector Legends: Character size is inadequate for the required viewing distance. Pont and character size is inconsistent between selectors of similar style. LOCATION: 2C14/24, 2Cl2/22, 2C11/21, OC10/20, 2C31 DESCRIPTION: Knob Selectors - Two position. RESOLUTION: l l Use standard legends. O A-22
4 HUMAN ENGINEERING DISCREPANCY E-123 COMMENT: Key Switch Legends: Character size is inadequate for the required viewing distance. Font and character size is
- inconsistent between selectors of similar style.
I LOCATION: 2C14/24 DESCRIPTION: ' Key Operated selectors - Key operated switch. O RESOLUTION: 1 Use standard legends. l O A-23
r HUMAN ENGINEERING DISCREPANCY E-112 COMMENT: Toggle Switch Legends: There are no legends (i.e., O, OFF) for toggle switches. Character size is inadequate for the required viewing distance. LOCATION: 2C14, OC10L DESCRIPTION: Toggle Switches - Two position, pull-to-release. The function label is located above the component and it is assumed that the upward position of the toggle accommodates the function. l RESOLUTION: Toggle switch positions will be clearly relabeled. Use stan-dard legends. O A-24
4 HUMAN ENGINEERING DISCREPANCY E-114 COMMENT: Thumbwheel Label: The OUTPUT HOLD does not clarify the required operation. LOCATION: 2Cl2, 2CllL DESCRIPTION: Vertical Thumbwheels - Bailey Meter Company, TGil, TG12, TG40, O Set Point Station. RESOLUTION: The function of the button is to stop the transmission of the signal until the desired number is set. For a trained operator, this terminolgy is as good as any other. A-25
HUMAN ENGINEERING DISCREPANCY E-115 l i
; COMMENT:
Thumbwheel Legends: Character size is inadequate for the required viewing distance. LOCATION: 2CllL DFSCRIPTION: Horizontal Thumbwheels - Bailey Meter Company, TG20 Bias Station. RESOLUTION: Use standard legends and labels. O A-26
HUMAN ENGINEERING DISCREPANCY E-005 COMMENT: Heater set Points: Values are not indicated on the panel. LOCATION: 2Cl2 DESCRIPTION: O Heater banks should be labeled as to the point at which turn on automatically to maintain pressure. they RESOLUTION: A review of panel enhancements with respect to identifying all set points on the panel surface resulted in a decision not to label set points. Such set points are provided in procedures; to put them all on the panel will unnecessarily clutter the panel and serve to distract operators. O A-27 !
HUMAN ENGINEERING DISCREPANCY E-001 COMMENT: Procedure Holders: Operators standing at the control panels (front and back) have no surface on which to place operating procedures. LOCATION: All panels. l 6 l DESCRIPTION: All operations except initial actions on emergency procedures are performed by direct reference to written procedures. Operators who are required to stand at the panels to operate equipment cannot easily refer to procedures, because the only surface provided is the single operator's desk. The use of the desk to hold procedures while operating panels will require the operator to turn his back to the panels. RESOLUTION: Consideration will be given to providing carts for procedures. This item will be reviewed again following manning of control room. O A-28
l l l l HUMAN ENGINEERING DISCREPANCY A-008 O COMMENT:
" Slow" and " fast" legends are curved around the dial face, each between an arrow. This labeling practice is not in accordance with HFE standards, but may be adequate in light of the unique display operation.
LOCATION: 2CllR, 2C15 DESCRIPTION: l Dials (circular or curved) - General Electric, synchroscope. RESOLUTION: These legends are standard for synchroscope operation. Although curved legends are not preferred, they are acceptable in this application. 1 1 A-29
l I j HUMAN ENGINEERING DISCREPANCY E-072 l COMMENT: Synchroscope: There is no label for this component. l LOCATION: e 2CllR, 2C15 DESCRIPTION: Dials (Circular or Curved) - General Electric, synchroscope. , RESOLUTION: Label will be provided. l 9 A-30 l
f i i I HUMAN ENGINEERING DISCREPANCY C-003 i i l COMMENT: 1 I Feedwater Control: Loops A and B. t 1 ) i l j LOCATION: I iI j 2Cllt I i j DESCRIPTION: i Arrangement of startup and main controls are not in the . sequence of normal operation. ) 4 4 h l l RESOLUTION: l ! Enhancements have grouped these controls to make their functions and relationships clear. I l A-31 i
-.. - .r,, , - - - , ,
l HUMAN ENGINEERING DISCREPANCY H-026 COMMENT: Steam Generator Levels During Heatup: Procedures require level at 98 to 99 percent (385-391 inches), but an interlock stops main feed at 310 inches. LOCATION: 2C11 DESCRIPTION: Plant operating specifications state that steam generator levels should cover feed nozzles during heatup and cooldown. Interlocks will not allow this level to be maintained. RESOLUTION: B&W states that maintaining level at 400 inches during heatup and cooldown is not required if constant feed flow is maintained during heatup or cooldown. Other B&W plants maintain lower levels during heatup and cooldown. Tne operating specification and procedures will be changed to require steam generator levels less than the 313 inch interlock during heatup and cooldown. O A-32
J I i HUMAN ENGINEERING DISCREPANCY H-016 J I COMMENT: i l Coolant Pumps Jumpers: In order to start coolant pumps when i the primary system is superheated, starting interlocks may
- need to be defeated with jumpers.
i s LOCATION: !t 2C22 } l DESCRIPTION: i i In the event of inadequate core cooling, the coolant pumps j s must be started immediately by defeating the starting interlocks if necessary, i i i i 1 1 i ! RESOLUTION: i j Plant procedures will include the methodology for jumpering 1 interlocks. I i t O l A-33 l
HUMAN ENGINEERING DISCREPANCY R-023 COMMENT: Boration Flow Rate: The batch controller flow rate is not compatible with letdown flow rate units. LOCATION: 2Cl2 DESCRIPTION: The procedure requires the batch controller flow rate be set to match the letdown flow rate in order to maintain primary inventory and makeup tank inventory. The batch controller uses percent flow, and letdown flow indication is calibrated in GPP. RESOLUTION: It is necessary to set the boric acid or demineralized water flow rate equal to the letdown flow rate to maintain makeup tank level constant. As there is no flow controller in the batch makeup lines, an approximate opening percentage of the throttle valves will be specified in procedures, after letdown is diverted and batch flow begins. The batch throttle valves can be adjusted to maintain constant makeup tank level. O A-34
' HUMAN ENGINEERING DISCREPANCY R-020 NN COMMENT:
; Cperation of Two Makeup Pumps: During reactor trip, two ; makeup pumps cannot be run for normal makeup to counter rapid primary cooling.
i I i LOCATION: 2C12 j i i DESCRIPTION: 4 (s On reactor trip, a rapid loss of pressurizer level can be ' V controlled with two makeup pumps running, two makeup however, the use of pumps is prohibited for technical reasons. The 4 alternative o f II. P . injection takes cold water from the BNST which will cause a stress cycle on the primary system. _ RESOLUTION: The NSSS vendor has stipulated that one makeup pump will i control pressurizer level during a normal reactor trip and it is not necessary to operate two makeup pumps. In the event of abnormal cooling after a trip, II.P. injection will be used if ! required. Procedure guidelines stating that two makeup pumps 1 1 are required following a reactor trip will be revised to reflect that only one pump is required. b !O A-35 l
HUMAN ENGINEERING DISCREPANCY R-021 COMMENT: Bypass Purification System: When offsite power is lost, there is no way to bypass purification systen. LOCATION: Plant. DESCRIPTION: When offsite power is lost, letdown flow can be restored by bypassing the purification system. But the valves required to perform the bypass f ail closed on loss of of fsite power and cannot be opened manually. RESOLUTION: Craft emergency procedure guidelines used in the task analysis recommended that letdown be manually restored following a loss o f o f f-s i te power. There is no safety requirement to restore i letdown, therefore, the procedure guidelines will be modified l to delete the section on manual restoration of letdown. 1 O A-36
HUMAN ENGINEERING DISCREPANCY O-006 O 1 COMMENT: Turbine Steam Seal Pressure: Pressure to seals can be adjusted from the secondary back panel, but there is no steam pressure indication at that panel. LOCATION: 2C21 DESCRIPTION: On reducing vacuum, the steam supply to seals should be O increased. The operator at the back panel has no indication of steam pressure to use as feedback to his control actions. RESOLUTION: Review of the operation of the steam seal valve revealed that this valve can be taken to the full open position without effecting seal operation. Seal pressure is provided in the plant computer. ) I i A-37 l 1
HUMAN ENGINEERING DISCREPANCY H-025 COMMENT: Bailey Setpoint Thumbwheels: These wheels are calibrated from 0 to 103 percent. They do not read in normal parameter units. LOCATION: 2Cl2, 2C13, 2C11 DESCRIPTION: Thumbwheels are numbered 0 to 100 and are calibrated as a percent of the full range of the parameter being set. The operator must refer to a table to determine what percent reading corresponds to the desired set point units for that parameter. RESOLUTION: Bailey thumbwheel setpoints stations in the Integrated Control System (ICS) are calibrated in engineering units. Setpoint stations in the Non-Nuclear Instrumentation (NNI) are calibrated in percent. These setpoint stations have either an analog meter in the immediate vicinity that can be used in conjunction with setting set points or have no direct correlation to engineering units. These setpoints are only changed during routine operations during periods of low stress, Use of percent on these setpoint stations is considered acceptable. O A-38
HUMAN ENGINEERING DISCREPANCY P-004 COMMENT: RCS flow. , LOCATION: 2Cl2 DESCRIPTION: Procedures speak of RCS flow as gallons O actual gauge measures percent flow. per minute while RESOLUTION: Procedures will be revised to indicate percent flow to match control panel units. l 10 l A-39
HUMAN ENGINEERING DISCREPANCY P-010 COMMENT: Primary Loop Pressure: Primary pressure is determined only by pressurizer. There are no loop pressure indicators. LOCATION: 2C12 DESCRIPTION: Various coolant pump combinations can cause a difference in loop pressure by variations in the loop flow. Tables used do not reflect the differences in pressure caused by di f f e r era t pump combinations. RESOLUTION: Operating procedures are based on pressurizer pressure with adequate allowance for the worst case loop flow combination. For this reason, individual loop pressure indications are not provided on the panel. O A-40
HUMAN ENGINEERING DISCREPANCY P-012 ( COMMENT: Exhaust Boot Spray: A jogging control for adjusting the boot spray is p ovided on the turbine panel, but there is no feedback indication. LOCATION: 2CllR DESCRIPTION: i The operator can increase spray by jogging open the control valve provided, but there is no means of determining how the spray flow has been affected. RESOLUTION: An alarm is provided in the control room to indicate high exhaust boot temperature. The temperature is available from the plant computer. If the alarm comes in, the operator jogs the valve to clear the alarm, he can then call up the required computer display to determine the exact temperature and to fine tune the control. O A-41
l HUMAN ENGINEERING DISCREPANCY H-024 COMMENT: Main Steam Isolation Valve (MSIV) : No gauge to determine when AP is less than 50 lbs. LOCATION: In plant. DESCRIPTION: Operator cannot open the isolation valve until the differential pressure across the seat is less than 50 lbs. He has no means for knowing when the AP has reduced to less than 50 lbs. RESOLUTION: Steam generator pressure and turbine header pressure are provided in the control room. These indications can be utilized to determine A P across MSIV. The MSIVs can be opened against much greater differential pressures, therefore, the exact AP is not critical to operations. O A-42
i HUMAN ENGINEERING DISCREPANCY H-029 ( I ! COMMENT: i Seal Pressure Indicator: The range of this meter is too wide to read pressures in the range of 45 to 100 PSIG. ] LOCATION: 1
- 2Cl2 i
DESCRIPTION: i The intent is to determine the differential pressure between s_) the seal header and primary loop. The controller for seal pressure is calibrated in differential pressure. . RESOLUTION: 4 l Differential pressure between the seal header and the reactor-
- coolant system can be obtained from the plant computer system i with the desired resolution. The real parameter being controlled is pump seal flow. -At low reactor coolant pressures the differential pressure across the flow valves is outside the control range of the, valves. The pressure controller is used to drop the makeup pump discharge pressure to within the range of the flow control valves. As reactor coolant pressure increases the pressure controller is bumped open to maintain the flow control valves within range.
- Therefore, the feedback required to operate the pressure controller is seal flow, not differential pressure.
p d A-43
l HUMAN ENGINEERING DISCREPANCY D-008 COMMENT: Turbine Bypass and Atmospheric Dump Valves: There is no positive position indication of the valve positions at the control panel. LOCATION: 2CllL DESCRIPTION: The valves are normally controlled by a Bailey controller which shows commanded position. There is no positive position indication. RESOLUTION: Turbine header pressure provides feedback on the proper operation of the Turbine Bypass and Atmospheric Dump Valves. valve position is a function of differential pressure and cannot be used to control the valve. The appropriate feedback is available to the operator. O A-44
l l () HUMAN ENGINEERING DISCREPANCY D-Oll COMMENT: High Pressure Injection Flow: Operator must mentally add seal flow, makeup flow, and injection flow to determine total pump flow. LOCATION: 2C14, 2C12 DESCRIPTION: During high pressure injection, the flow through a makeup pump C/) s_ must be between 100 and 600 gpm to prevent pump runout or shutoff. Three different flow meters on two different panels must be used to determine total flow. RESOLUTION: Simultaneous maintenance of high pressure injection flow and makeup flow would only occur with reactor coolant pressure greater than 1500 psig. At this back pressure, runout is not a problem due to the characteristics of the pump and fluid system. High pressure injection flow by itself will be maintained greater than 100 gpm per pump independent of makeup flow. Low suction flow alarms are also provided to alert the , operator that he is approaching pump deachead conditions. l Based on the above, total makeup pump flow will be maintained within required limits by system constraints or through the use of the two injection flow indications only. This item is considered not to be a deficiency. O G A-45 l
HUMAN ENGINEERING DISCREPANCY D-014 COMMENT: Makeup Pump Recirculation Indication: There is no indication o f makeup pump recirculation flow in the control room. LOCATION: 2C14 DESCRIPTION: If a makeup pump is started against a shutoff head because of incorrect lineup, it could be burned out in a short time. RESOLUTION: A low suction flow trip was previously added to the pump control logic to protect against running the pump against shutoff head. Additionally, a low suction flow alarm is provided in the control room. These features are sufficient to protect the pump. l O A-46
HUMAN ENGINEERING DISCREPANCY D-015 COMMENT: Auxiliary Feedwater Recirculation Indication: There is no indication of auxiliary feedwater recirculation flow in the control room. LOCATION: 2Cll DESCRIPTION: an auxiliary feedwater pump is started against a shutoff O If head because of incorrect lineup, short time. it could be burned out in a RESOLUTION: f Lights are provided on the control panel indicating that the recire flow path is correctly aligned. The recire valve is automatic and opens on low flow. The recire valve control is : located on the control panel, with lights to indicate its position. This provides sufficient indication to the operator to assure pump protection. l O A-47 l
l HUMAN ENGINEERING DISCREPANCY D-016 COMMENT: Differential Tc Control / Indication: When manipulating the controller, the indication cannot be read. LOCATION: 2C12, 2Cll DESCRIPTION: The controller and indication are on different panels which are separated by the Reactor panel (2C13). The indication cannot be read from the control station. RESOLUTION: This controller is used very infrequently to adjust feedwater flows to each steam generator to equalize the cold leg temperatures in each loop. Feed flows are on the panel with the controller. The differential temperatures of the cold legs are indicated directly on the controller (Bailey TT-10) indicator. Sufficient feedback information is available at the controller to perform required functions. O A-48 l
HUMAN ENGINEERING DISCREPANCY D-018 O I COMMENT: l .; Main Feed Pump Trip: There is.no direct feedback to operator i that indicates that the feed pump has tripped. l I I LOCATION: I 2Cll DESCRIPTION:
! The operator must trip the main feed pump by tripping the j booster pump and allowing the interlock to trip the main feed pump. There is no direct panel indicator that confirms that the feed pump has tripped. The trip must be inferred by a drastic reduction in feed flow and pump discharge pressure. A direct indication would be helpful to the operator.
RESOLUTION: The feed pump will only be tripped from the control room during emergency conditions to limit feed flow to the steam generators. The reduction in feed flow is sufficient feedback for these conditions. Safety-grade feed isolation valves are available to isolate feedwater in the unlikely event the feed pumps fail to trip. O A-49
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l 4 I i i I CONTROLS O ai l i i I I I O
I b i i 1 HUMAN ENGINEERING DISCREPANCY A-027 i i i i COMMENT: l Reach distance to the selector requires torso flexion and l rotation. I { LOCATION: i
'C15 4
DESCRIPTION: 4 $ J-Handle Selector - General Electric, tap changer. ] I l 1 1 i RESOLUTION: 4 I Flexion and rotation is minimal and is acceptable to operate l these controls. These are infrequently used. 4 4 i A-50 1
HUMAN ENGINEERING DISCREPANCY A-025 CCMMENT: Reach distance to the selector requires torso flexion and rotation. LOCATION: 2Cl4/24, 2C22, 2Cll/21, OC10 2C15 DESCRIPTION: J-Handle Selectors - General Electric, pointer type, flag type. RESOLUTION: Removed handrail thereby reducing reach distance. Flexion and l rotation is minimal and is acceptable to operate these controls. l O 1 l A-51
HUMAN ENGINEERING DISCREPANCY A-C01 COMMENT: j ' Reach distance to the selector requires torso flexion and rotation. r LOCATION: 2C15 l i DESCRIPTION: , J-Handle Selector i I f I, RESOLUTION: ! Torso flexion and rotation is minimal to operate this switch, t The switch will be used'very infrequently and is considered to i be satisfactory. l l k A-52 ,
l l HUMAN ENGINEERING DISCREPANCY A-021 COMMENT: Reach distance to the pushbutton requires torso flexion and rotation. I LOCATION: OClCL, 2C12, 2C14L, 2C31 DESCRIPTION: Pushbuttons - General Electric, palm actuated, white, yellow. 4 RESOLUTION: Pushbuttons on vertical panels are used for emergency conditions and are thus used infrequently. Torso flexion and rotation is minimal to operate. O A-53
4 f ) l HUMAN ENGINEERING DISCREPANCY A-C30 1 1 COMMENT: t l Reach distance to the pushbutton requires torso flexion and j rotation. l i j LOCATION: i l 2Cl4, OC10L, 2C35 . I DESCRIPTION: J r ! \ Pushbuttons - Oeneral Electric, flush mounted, unguarded, ) black, white, red, orange. l 1 s I i I i i 1
- RESOLUTION:
)
1 l i l l Re.T.oved handrail thereby reducing reach distance. Flexion and i rotation is minimal and is acceptable to operate these controls. These are infrequently used. 1 I J l 4 I . l i A-54 4
l l HUMAN ENGINEERING DISCREPANCY A- 0 2 /. COMMENT: Reach distance to the selector requires torso flexion and rotation. LOCATION:
. 2Cl4/24 DESCRIPTION:
Key Operated Selectors - General Electric, key operated switch. RESOLUTION: Removed handrail thereby reducing reach distance. Flexion and l rotation is minimal ano is acceptable to operate these controls. These are infrequently used. 1 O l A-55
; HUMAN ENGINEERING DISCREPANCY A-028 COMMENT: [
distance to the switch requires torso flexion and rota- ! Reach tion. i I i i LOCATION: 2C14, CC10L j i I i DESCRIPTION:
) Toggle Switches - (mfg unknown), two position, pull-to-release. ;
l [ I i j i.
?
t I ) ! RESOLUTION: f r i Removed handrail thereby reducing reach distance. Flexion and ! rotation is minimal and is acceptable to operate these ! controls. These are infrequently used. ! i I t k A-56 : i
HUMAN ENGINEERING DISCREPANCY A-029 COMMENT: Reach distance to the thumbwheel requires torso flexion and rotation. l
) LOCATION:
2C11L DESCRIPTION: Horizontal Thumbwheels - Bailey Meter Company, TG20 Bias Station. i RESOLUTION: Removed handrail thereby reducing reach distance. Flexion and rotation is minimal and is acceptabld to operate these controls. These are infrequently used. O A-57
f HUMAN ENGINEERING DISCREPANCY A-022
}
COMMENT: Reach distance to the pushbutton requires torso flexion and rotation. i 4 LOCATION: i 2C14/24, 2Cl2/22, 2Cll/21, OC10/20, 2C31 DESCRIPTION: i: nob Selectors - General Electric, two position, three Ox position, spring loaded to center. . RESOLUTION: 1 I I' Removed handrail thereby reducing-reach distance. Flexion and rotation is minimal and is acceptable to operate these controls. O I I J A-58 l f i
l l 1 HUMAN ENGINEERING DISCREPANCY E-090 COMMENT: Bailey Controller: Meter toggle switch legend is not adequately spaced or aligned to the switch. The meter on the controller shows valve position or setting. It is not known whether this is the commanded or the actual response position or setting. LOCATION: 2Cl2, 2Cl3, 2CllL DESCRIPTION: Integrated Control Units - Bailey Meter Company, TT10 Transfer Station. The meaning of legend information (i.e., POS and DEV) is not understood and should be clarified. The controller is used in many functions for the primary and secondary plant. It must be determined for each meter what the operator is reading on the scale in terms of command and response. RESOLUTION: Revise labels to identify meaning of POS/DEV positions on
- toggle switch. The meters on the Bailey controllers indicate demand output, there is, however, sufficient feedback from l other control panel indicators to provide the operator with required system information.
O A-59
1 l l l l HUMAN ENGINEERING DISCREPANCY E-086 1 0 COMMENT: Bailey Controller: Legend character size is inadequate for the required viewing distance. The meaning of symbols on the pushbuttons are somewhat ambiguous. Color coding of the pushbuttons is inconsistent with color code. Size of pushbuttons is too small. LOCATION: 2C12, 2C13, 2C11L DESCRIPTION: O Integrated Control Units - Bailey Meter Company, TT10 Transfer Station. There is no precedent elsewhere in the control room for their definition. Operators envision all control actions with this component as either increasing or decreasing. The arrows to left and right not to connote increase-decrease. Arrows should be pointed u p-d own . Color should indicate automatic or manual operation. RESOLUTION: Use standard legend. Arrow direction on the pushbuttons coincides with increasing / decreasing direction of movement on the associated meter and is considered acceptable and consis-tent for operation. Pushbutton size was considered acceptable. 1O A-60
HUMAN ENGINEERING DISCREPANCY E-093 COMMENT: Pushbutton Colors: There is inconsistency between legend colors and pushbutton color; legend fonts and characters are inconsistent. LOCATION: OC10L, 2C14, 2C35 DESCRIPTION: Pushbuttons - Flush mounted, unguarded, black, white, red, orange. For example, there are black pushbuttons for " arming",
" reset", " block", white pushbuttons for " reset", and yellow pushbuttons for " test". It is unknown what the colors black and white represent in the code. Not all red and amber pushbuttons are guarded, leaving some red and amber pushbuttons appearing differently and less identifiable than others. The reset buttons for Energency C;ce Cooling are white while other reset buttons are orange. Black and bypass buttons are also yellow.
RESOLUTION: Use standard legends. Color codes for all pushbuttons have been specified, and pushbuttons will be colored appropriately. O A-61
i E-094 O HUMAN ENGINEERING DISCREPANCY ! I i \ COMMENT: r i Reactor Trip Pushbutton Legends: Legends are obscured. i LOCATION: : l 2C14, OC10L, 2C35 e DESCRIPTION: , I , Pushbuttons - guarded, red. s Reactor trip buttons differ from other guarded pushbuttons in > their height above the panel and in- guard color, which is chrome instead of red. The height of the button and its ! location well back on the panel obscure its legend from the operator's view. l RESOLUTION:
,t I
i Legends will be placed so they can be seen. i t [
} ,
i ' i A-62 !
HUMAN ENGINEERING DISCREPANCY E-097 g COMMENT: Annunciator Pushbutton Legends and Labels:: Legend fonts and character size vary between pushbuttons of the same style. The acknowledge button is labeled "ACK". LOCATION: 2C14L, 2Cl2, OC10L, 2C31 DESCRIPTION: Pushbuttons - Palm actuated, white, yellow. ACK should be spelled out (e.g . , ACKNOWLEDGEMENT) . RESOLUTION: Use standard legends and terminology. O A-63
HUMAN ENGINEERING DISCREPANCY E-999 1 i l COMMENT: , I Annunciator Pushbutton Colors: Yellow pushbuttons are for i annunciator ACKNOWLEDGEMENT and TEST. White pushbuttons are ; for annunciator RESET. Controls for acknowledging annunciator alarms can be confused with annunciator reset and test controls. Spacing between buttons is insufficient for full palm actuation. Spacing is also inconsistent between the buttons on different panels. On some panels, there is a 2-inch spacing between "ACK" and " RESET" and on others, a 3-inch space. LOCATION: 2Cl4L, 2C12, OC10L, 2C31 O DESCRIPTION: d Pushbuttons - Palm actuated, white, yellow. Determine, according to color convention, the appropriate color of each annunciator control pushbutton. The three large buttons are physically alike. An operator reaching for the acknowledge button can easily mistakenly depress the reset or test button. RESOLUTION: Use standard pushbutton color code and replace RESET and TEST with finger pushbuttons. 4 A-64
l l HUMAN, ENGINEERING DISCREPANCY A-017 COMMENT: ' Pushbutton is larger than specified, but adequately guarded and identified. LOCATION: 2C14/24, 2Cl2, 2C21L, OC10L DESCRIPTION: Pushbuttons - General Electric, flush mounted, unguarded, black, white, red, orange. RESOLUTION: The larger pushbutton, because it is properly guarded, is not considered detrimental to operator performance. O A-65
I () HUMAN ENGINEERING DISCREPANCY A-014 COMMENT: Pushbutton " bo t tom-o u t" is the only indication of activation; however, associated indicators provide immediate feedback of action initiation. 1 LOCATION: 2C14/24, 2C12, 2C21L, OC10L DESCRIPTION: Pushbuttons - General Electric, flush mounted, unguarded and guarded, black, white, red, orange. General Electric, palm actuated, white, yellow. RESOLUTION: Although no snap or click is provided with these controls it was determined that a feedback mechanism was available for pushbutton activation indication.
- O A-66
HUMAN ENGINEERING DISCREPANCY R-005 COMMENT: Pushbuttons: Failure will be revealed only by the lack of system response. LOCATION: 2C14, OC10L, 2C35 DESCRIPTION: Pushbuttons - Ceneral Electric, flush mounted, unguarded, black, white, red, orange. Verify that lack of system response will be obvious to the operator within time constraints required for safe operation of the system. RESOLUTION: All pushbuttons were reviewed by the team. All were found to have immediate system feedback that indicated they operated properly. O A-67
4 i 1 () HUMAN ENGINEERING DISCREPANCY R-006 COMMENT: Annunciator Pushbuttons: Failure will be revealed only by the j lack of system response. i 1 1 I j LOCATION: 2C14L, 2Cl2, CC10L, 2C31 I DESCRIPTION: Pushbuttons - Palm actuated, white, yellow. Verify that lack of system response will be obvious to the i operator within time constraints required for safe operation i of the system. 1 i RESOLUTION: l l These pushbuttons have an immediate visual response from the associated annunciator panel. A failure to operate will be immediately detected. A-68
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HUMAN ENGINEERING DISCREPANCY A-003 COMMENT: J-handle is 1.75 inches shorter than minimum specification. LOCATION: i 2C14, 2Cl2, 2Cll/21, OC10L, 2C15 DESCRIPTION: J-!!andle Selectors - General Electric, pointer type, flag type. RESOLUTION: Control size is adequate in consideration of the low actuation force required. O A-69
HUMAN ENGINEERING DISCREPANCY A-010 COMMENT: Legends are sloped. LOCATION: 2C14, 2C12, ?Cll, OC10L DESCRIPTION: l J-Handle Selectors - General Electric, pointer type, flag O\ type, tap changer, synchronizing breaker. RESOLUTION: Sloped legends have large character size and high contrast ratio. Their slope is not expected to effect legibility or readability. I l O l A-70
HUMAN ENGINEERING DISCREPANCY A-007 COMMENT: OFF is straight up and ON is 45 degrees to right. LOCATION: 2C15 DESCRIPTION: J-!!andle Selector - Ceneral Electric, synchronizing breaker. RESOLUTION: Operation of this control is conducted infrequently and when used, done in a deliberate manner, therefore this is considered acceptable. O f A-71 1 1
HUMAN ENGINEERING DISCREPANCY H-008 COMMENT: Tap Changer: Operation of the control varies between vendors. Tap Changer Selector: Handle designs vary between selectors for the same function. LOCATION: 2C15 DESCRIPTION: O J-ilandle Selector - General Electric, tap changer. Westinghouse, tap changer. On the General Electric tap changer AUTO is to left, RAISE and LOWER to the right. With the Westinghouse selector, pull is for AUTO, RAISE to the right and LOWER to the left. RESOLUTION: Since tap changers are used for infrequent, minor adjustments, during normal operation, and not at all during emergency operations, their operation is deliberate with no stress. Based on above, this was considered acceptable. I () A-72 l t
1 HUMAN ENGINEERING DISCREPANCY P-Cl2 COMMENT: Tap Changer: Failure will be revealed only by the lack of system response. LOCATION: 2C15 DESCRIPTION: J-!!andle Selector - Ceneral Electric, tap changer. Westinghouse, tap changer. Verify that lack of system response will be obvious to the operator within time constraints required for safe operation of the system. RESOLUTION: The tap changer makes fine adjustments to voltage. outputs of transformers. These operations are conducted only under normal, steady-state conditions. Feedback is immediately available at voltmeters on the associated buses. This is not a ciscrepancy. O A-73
t j HUMAN ENGINEERING DISCREPANCY E-105 l i l t l l COMMENT: General Electric Pointer Switches: Some of these selectors have a white border with a number mounted across the top of j the plate. I l, LOCATION: j 2C14, 2Cl2, 2C11/21, OC10L i i DESCRIPTION: !j J-itandle Selectors - General Electric, pointer type. I i a i l i I ! RESOLUTION: i 4 1 l 2 This number is manufacturer's serial number. It is small and not considered to be a distraction. I i 1 1 I A-74 i
HUMAN ENGINEERING DISCREPANCY E-108 COMMENT: General Electric Flag Switch: GE logo and part number should not be visible on the front of the component. LOCATION: 2C24, 2C22, 2Cll/21, OC10L, 2C15 DESCRIPTION: J-!!andle Selector - General Electric, flag tvpe. Determine if logo is actually distracting. RESOLUTION: Logo is very small and not distracting. I O A-75
. _-_ - - . _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ~
() HUMAN ENGINEERING DISCREPANCY R-016 ' COMMENT: , t
- Selector Control
- Po si tion of the pointer between both i settings (i.e., straight up) does not convey the most recent setting. This information must be obtained from system indicators.
LOCATION: 4 2Cl4, 2Cl2, 2Cll/21, CC10L i i DESCRIPTION: j J-Handle Selectors - Ceneral Electric, pointer type. Reexamine detailed use of this component to determine how ! operators obtain information from it. I i 4 4 I RESOLUTION: a
! There is no reason for the operator to have knowledge of the l last position of the control switch. The switch will always perform its function in either direction independent of the last position. Contacts within the switch " remember" the last position and are utilized to qualify alarms. This is not considered to be a discrepancy.
I
- O A-76
HUMAN ENGINEERING DISCREPANCY R-013 l l COMMENT: l Breaker Control: Failure will be revealed by the lack of system response. LOCATION: 2C15 DESCRIPTION: J-Handle Selector - General Electric, synchronizing breaker. Verify that lack of system response will be obvious to the operator within time constraints required for safe operation of the system. RESOLUTION: Operation of these controls energizes the synchroscope thus feedback is inmediately available on the associated panel. This is not a discrepancy. t A-77 1
() HUMAN ENGINEERING DISCREPANCY R-009 COMMENT: Key switch: Failure will be revealed only by the lack of system response. LOCATION: 2C14/24 DESCRIPTION: Key Operated Selectors Switch. [ Verify that lack of ystem response will be obvious to the operator within time constraints required for safe operation of the system. RESOLUTION: All key switches were reviewed by the team. On the turbine panel, the block start sync switch has no immediate feedback. This switch bypasses generator breaker sync interlocks. It would be determined in a short time frame if the interlock failed as the generator breaker could not be closed. O j A-78 i I..__ - _ _ _ _ . - - _- ._. - --
HUMAN ENGINEERING DISCREPANCY A-005 4 COMMENT: Control size is not as large as specified. LOCATION: 2C14/24, 2Cl2/22, 2Cll/21, OC10/20, 2C31 i I DESCRIPTION: Knob Selectors - General Electric, two position. RESOLUTION: Control size is adequate in consideration of the low actuation force required. O A-79
HUMAN ENGINEERING DISCREPANCY R-Cll O COMMENT: Knob Selector: Failure will be revealed only by the lack of system response. LOCATION: 2C14/24, 2C12/22, 2Cll/21, OC10/20, 2C31 DESCRIPTION: Knob Selectors - Two position. d Verify that lack of system response will be obvious to the operator within time constraints required for safe operation of the system. RESOLUTION: All knob switches were reviewed by the team. Two groups of selector switches for primary and secondary instruments are loca te(t on the back panel and have no feedback on the back panel. These switches were located on the back panel to prevent unwarranted shifting of meter inputs with the concomitant possibility of inserting large step functions into automatic control systems. Use of these switches will require direct communications between the back panel operator and the front panel operator, where feedback information is immediately available.
- O i
I A-80
HUMAN ENGINEERING DISCREPANCY H-007 COMMENT: I Vertical Thumbwheels: Operation of this control requires two hands. LOCATION: 2C11, 2Cl2 DESCRIPTION: Vertical Thumbwheels - Bailey Meter Company, TGil, TG12, TG40, Set Point Station. The component is located up to 36 inches lateral reach distance, making torso rotation impossible and extension impractical. This reach distance is excessive. RESOLUTION: Handrails will be removed on all panels. This will reduce the reach distance by over 3 inches. These setpoint controllers can be easily manipulated with one hand, thus requiring only body rotation. These controllers are operated primarily under normal operating conditions and are changed infrequently. Operation is judged to be satisfactory. O A-81
1 () HUMAN ENGINEERING DISCREPANCY R-010 i COMMENT: j Feed Pump Bias Control: Failure will be revealed only by the lack of system response. i 1, 1 j LOCATION: 4 1 j 2Cllt
. DESCRIPTION:
1 a Horizontal Thumbwheels - Bailey Meter Company, TG20 Bias i Station. Verify that lack of system response will be obvious to the operator within time constraints required for safe operation of the system.
- RESOLUTION
1 The operation of this bias controller has inmediate feedback on feed pump speed indicators. This is not a discrepancy. f l l I A-82 l
HUMAN ENGINEERING DISCREPANCY H-009 COMMENT: Turbine Bypass Controllers: There are two controllers that are used to perform the same function. LOCATION: I 2Cll DESCRIPTION: The use of two Bailey controllers to perform the same function can lead to misunderstanding and error. These are used extensively during abnormal transients. RESOLUTION: Investigation revealed that the controllers do not have identical functions. A-83
i l H-010 O HUMAN ENGINEERING DISCREPANCY 1
, COMMENT:
I Aux Feed Level Controller: Scales are difficult to read in l areas on the scale that have lights in the background. 1 i i i LOCATION: i 2Cll
- )
i DESCRIPTION: i The Foxboro controllers provide lights embedded in the scale j, background both at the top and bottom of the scale. These are ! presumably intended to signal high and low limits. When i extinguished the dark background caused by the light makes the
- scale difficult to read.
i 7 i ( RESOLUTION: These lights are located outside of the normal operating range of the indicators and do not result in a significant reduction in the ability of the operator to read the meter. !O l l A-84 l l
HUMAN ENGINEERING DISCREPANCY C-002 l l COMMENT: RC Letdown: Flow shutoff control. l LOCATION: 2Cl2 r DESCRIPTION: Valve 2SV-0404, which isolates letdown flow, should be more prominent. RESOLUTION: This valve has been confirmed as the normal valve used to stop letdowr flow. The control has been highlighted through enhancements to indicate its prominence. l l O A-85
.- . _ . . .. -. ._. __=.~ .
HUMAN ENGINEERING DISCREPANCY H-018 COMMENT: Main Feed Pump / Aux Feed Pump Interlock: Bypass switch is located in another room. LOCATION: , Safety Equipment Room DESCRIPTION: When main feed pumps stop, aux feed pumps start automatically. O During some operations it is not desirable to automatically initiate aux feed when the feed pump is tripped. To prevent this, the operator must leave the control room to actuate the bypass switch which is located in the Safety Equipment Room. l RESOLUTION: This HED was based on procedure guidelines which originally required transferring to auxiliary feedwater immediately after shutting down with a steam generator tube rupture. It was subsequently determined that not using the main feed system if it was available was not prudent. Therefore, the procedure guidelines were changed to allow staying on main feedwater if it is available. Auxiliary feedwater will be iritiated either due to automatic actuation, in which case the bypass would not be required, or by deliberate lineup. If deliberately lined up, sufficient time will exist to bypass O the main / aux feed interlock which is located immediately adjacent to the control room. A-86
HUMAN ENGINEERING DISCREPANCY H-032 COMMENT: Rod Contro'. Manual IN-OUT Joy Stick: This control for rod movement moves up to drive rods in, and down to withdraw rods. LOCATION: 2Cl3 DESCRIPTION: Rod motion is up to withdraw, down to insert. The lever is on Rod Control Panel which is located on the slanted benchboard. The lever must be pulled toward the operator to withdraw rods, and pushed away to insert the rods. This is opposite to the sense of the board where toward the operator is down, away from the operator is up. The control lever is also opposite to the arrangement of the Out and In lights on the same control panel. RESOLUTION: l This control is clearly labeled. Discussions with operators indicated no significant operational consequences, particu-larly since the Withdraw direction is a pulling motion, l consistent with terminology of ' pulling rods'. O A-87
4 i l HUMAN ENGINEERING DISCREPANCY H-027 4 O l 1 COMMENT: i i Emergency Boration: Controls for this operation are located j outside control room. I ;
- 1 LOCATION:
1 In plant.
- DESCRIPTION:
5 l Consideration should be given to placing the controls for 3 initiating EBS on 2C14 or 2Cl2. i l i l RESOLUTION: i j Emergency boration is not required in the short term. A 1 minimum of two hours is available before the contents of the 4 EBS tank must be injected into the primary. This is i sufficient time to perform the manual valve lineup which is , required. i O A-88
HUMAN ENGINEERING DISCREPANCY T-001 COMMENT: Spray Controls: Arrangement of pressurizer spray control valves may be confusing. LOCATION: 2Cl2 DESCRIPTION: Operating pressurizer spray control valves requires operator to start in the center of the functional arrangement, to select manual or auto, then move to the lef t of center to select the valve to be operated, then to the right to actually actuate the valve. RESOLUTION: The spray valve to be used is usually determined ahead of the time to be used. In any case, the order, as installed, is correct. Enhancements have made their functions clear. O A-89
l HUMAN ENGINEERING' DISCREPANCY T-002 (} COMMENT: Pressurizer Operation: Controls are on back panel. LOCATION: 2C22 DESCRIPTION: O Manipulation of pressurizer controls is performed from back panel 2C22, but indications of pressurizer parameters are on front panel 2Cl2. RESOLUTION: Necessary controls for operating the pressurizer are conveniently located on the front panel. The only controls on the back are for the pressurizer sample line isolation. The sample line is operated under specific conditions and does not require additional indication on the back panel. O A-90
i HUMAN ENGINEERING DISCREPANCY T-007 COMMENT: POAV Control: The power operated atmospheric vent is not positioned well to control the primary cooldown under emergency conditions. LOCATION: 2C31 DESCRIPTION: The location of the POAV on 2C31 will require an operator to remain at that panel to control primary emergency cooling through the steam generator. Control of steam generator feed is located on 2Cll. This may result in operator coordination problems. RESOLUTION: The POAV is a safety grade backup to the normal method of cooling down the plant. The use of the POAV cooldown is an operation that will commence later in the emergency actions. Operation of the POAV includes jogging open slowly to establish a cooldown rate and is only jogged periodically. Information required to determine the cooldown rate is available at the 2C31 panel. O A-91
/~D HUMAN ENGINEERING DISCREPANCY D-006 I i N sl COMMENT:
Coolant Pump Controls: RCP controllers are on the back panel. LOCATION: 2C24 DESCRIPTION: ( Main and associated system controls and indications for the s ,/ four reactor coolant pumps are on the back panel. Annunciator alarm panels on console 2Cl2 are the only direct indication of RCP casualties. l 1 RESOLUTION: I The task analyses did not reveal any difficulty with having the reactor coolant pump controls on the back. A coolant pump trip pushbutton is available on the front safeguards panel that will cause all pumps to be tripped. Annunciator- alarms and seal flow indications are all available on the front panel. CRT displays present alarm readouts, and other displays summarize coolant pump parameters. This coverage is considered to be sufficient under abnormal conditions. Starting the coolant pumps is a normal operation that is done in a deliberate manner. Two operators are required, one front, one back, in communication with each other. O A-92
HUMAN ENGINEERING DISCREPANCY P-003 COMMENT: Feedwater controls. LOCATION: 2Cll i DESCRIPTION: It is necessary to leave "at-controls" to secure the feedwater pumps. RESOLUTION: The main feedwater pumps are steam driven. By design they are tripped automatically when their respective motor driven feed booster pumps are tripped. Each set of main feed / booster pumps is intended to operate as a unit - the feed pump is never operated without its booster pump operating. The task analysis revealed that it was possible to trip the main feed pump by tripping the booster pump. Controls for tripping the booster pump are on the front panel. The booster pump control switch actuates the main feed pump trip by a "b" contact, thus it directly controls the main feed pump trip. There are no main feed pump controls on the back panel. This is considered not to be a discrepancy. A-93 l
a ,u_a, 2 _ ._ ~ - - - - - - - - - l l i l 1 l t DISPLAYS
l i HUMAN ENGINEERING DISCREPANCY D-003 COMMENT: Transient Diagnosis: Information needed to diagnose and respond to abnormal transients is spread throughout the control room on both front and back panels, i LOCATION', 2C14/24, 2Cl2/22, 2Cl3/23, 2Cll/21, OC10/20, 2C15, 2C31 DESCRIPTION: There is no central location where an operator can observe the O' dynamic plant operation to diagnose problems and decide upon corrective actions. The two contro4 operators must manipulate and monitor controls and indicators on five main front panels plus the Common Panel spanning a distance of 47 feet. In addition, other key indicators and controls are located on the Post Accident Monitoring Panel, and Electrical Panel both 16 feet from the operators. Although all these panels are within view, the distances are often too far to observe plant para-meters or status. RESOLUTION: The shift organization during o f f-no rmal and emergency operations provides fr.r a four man team consisting of two operators, the shift supervisor, and the shift engineer (technical advisor). They will be significantly aided in plant diagnosis by the SPDS which will be available not only on a dedicated SPDS display, but also on other CRTs in the l control room. l l O A-94
HUMAN ENGINEERING DISCREPANCY D-005 l COMMENT: Rod Height Indication: There is no way to simultaneously observe the height of all rods within a group LOCATION: DESCRIPTION: Simultaneous indications of rod heights are not possible. Individual rods must be called up one at a time. Gross indications (red, green, blue, and yellow lights) for individual rods are not dependable for establishing a good understanding of rod configurations. RESOLUTION: A CRT display showing the position of individual rods within a group will be available to the operator. O A-95
i t i () HUMAN ENGINEERING DISCREPANCY D-010 i i COMMENT: [ i, Primary Flow and Level Recorders: It would be useful to have j a recording of primary flow and pressurizer level on the front ! panel. I i f i LOCATION: i i i' 2C12 i l DESCRIPTION: O There are parameters recorders not on the primary back panel for some recorded on the front panel. Recordings of recent parameter history is sometimes useful to the operator. ; i l t f l RESOLUTION: - During normal operations, primary flow changes only in dis-crete steps as a function of the number of coolant pumps and changes in discrete steps. Any degradation of flow occurs over such long time periods that it would not be detectable on ,
- a trend recorder. For post accident conditions specific rules
- for pump operation apply; these rules specify when pumps are ;
; operated based on primary temperature and flow conditions.
For the above reasons, a primary flow recorder is considered ! unnecessary. A recorder indicating pressurizer level is pro- t O vided on the Primary Panel. provided on the SPDS. Level in the primary hot legs is ; i i A-96 1
HUMAN ENGINEERING DISCREPANCY D-012 COMMENT: Operation of Turbine Bypass Valve: Operator cannot see the primary pressure gauge when operating the bypass valve. LOCATION: 2Cll DESCRIPTION: During plant heatup and cooldown, the primary pressure and temperature are controlled by adjusting the turbine bypass valve. From the valve operating location, the primary gauges cannot be read. RESOLUTION: Computer CRT displays, including the SPDS, provide necessary primary parameters to the secondary operator. O A-97
HUMAN ENGINEERING DISCREPANCY D-017 O COMMENT: Abnormal Transient Parameter Trends: Some means of comparing key parameters and their trends is required to monitor and diagnose abnormal transients. LOCATION: 2Cl2, 2Cll DESCRIPTION:
?
r Combinations of parameters and trends are needed to apply the O symptom-oriented emergency operating procedures effectively. None of the recorders provide this monitoring capability. ! Mental calculations by the operator may be effective and may overload the operator. t i s i RESOLUTION: The SPDS is used to indicate the safety status of the plant. Trending of some parameters will be available in the SPDS. . Other safety parameters of importance are trended at the Post l Accident Monitoring panel (2C31). ' i lO A-98
HUMAN ENGINEERING DISCREPANCY H-002 COMMENT: Normal and emergency lube oil availability. LOCATION: 2CllR DESCRIPTION: Turbine lube oil indications and the availability of emergency lube oil should be indicated on the front panel 2CllR rather than rear panel 2C21. These indications are critical for proper turbine operations. RESOLUTION: Parameters for each bearing in the main lube oil system will be provided on a computer generated CRT display. This display combined with the annunciator alarm and computer alarm display will provide adequate coverage of these parameters. l O A-99
HUMAN ENGINEERING DISCREPANCY H-004 i COMMENT: Containment Pressure Indicator: There is no front panel indi- l cation of reactor building pressure. Steam ruptures in the i containment would likely indicate as an immediate pressure i increase in the reactor building. j LOCATION: 2C35 DESCRIPTION: Reactor building pressure indicator. O RESOLUTION: Containment pressure is indicated on panel 2C31. Because this panel is not close enough to be read directly by operators at their normal stations, containment pressure has been included on the SPDS display. Panel 2Cl4 has three annunciator alarms for containment pressure. O A-100 u______.___. _ - _ , _ _ --- - -
HUMAN ENGINEERING DISCREPANCY H-012 COMMENT: Computer Controlled Trend Recorders: There is no means of identifying what is being recorded. Each recorder has three identical scales for 0 to 100 Many different functions may be presented on the recorders. Some may not have units compatible with a 0 to 100 scale. LOCATION: 2C12, 2C11 DESCRIPTION: Each recorder has four pens, each of which can be assigned by the computer a variety of functions to be recorded. There is no mechanism to identify to the operator what is being recorded. For many of the parameters that could be presented on the recorder, a scale of 0 to 100 will require translation or calculation by the operator to determine the correct reading. RESOLUTION: During task analysis and validation walkthroughs, no requirements were identified for display on these recorders. They are intended for flexible use by the operators in recording any parameters they may require. A computer display will identify what quantities are assigned to each recorder pen and specify the scale dimensions. If later operation identifies parameters that are required to be presented on any of these recorders, the designated parameters will be administratively assigned and permanent legends will be affixed to the designated recorder. A-101
HUMAN ENGINEERING DISCREPANCY H-015 COMMENT: Rod Position on Computer: The computer receives only the type I of position indication (relative or absolute) that is selected on the Group Position panel. LOCATION: 2C13 l l DESCRIPTION: 1 The plant computer has various programs (including SPDS) which O utilize rod position. follow actual position following a reactor trip, the computer As the relative rod position does not does not have a true indication of rod position. l l l RESOLUTION: The control rod drive control system will be modified to provide absolute rod position to the plant computer independent of the position of the selector switch in the control room. O A-102
HUMAN ENGINEERING DISCREPANCY H-019 COMMENT: Incore Thermocouple Temperature Scales: Scales are very wide range and can only be read to within 25 degrees F. LOCATION: 2C31 DESCRIPTION: Readouts have a scale from 0 degrees F to 2300 degrees F. Readability of the temperature to within 25 degrees F may not be adequate for the required function. Accurate temperatures can be read with a millivolt meter in another room but this may result in operator overload and time delays. RESOLUTION: The incore thermocouple temperature indicators are provided as backup to the plant computer, where these temperatures are displayed as part of the SPDS. The incore temperature readings are utilized in the emergency procedures to determine actions to be taken in the event of inadequate core cooling. The actions to be taken are based on a graph of incore temperature versus reactor coolant pressure. Readability of the temperature to better than 25 degrees F would not signifi-cantly improve the operators ability to determine the operating point on this graph. Based on this, the readability of the incore thermocouple is considered acceptable. A-103
i , HUMAN ENGINEERING DISCREPANCY H-020
}
COMMENT: Subcool Meter: Meter is difficult to interpret, and is not compatible with ATOG approach. LOCATION: i i 2C12 . t DESCRIPTION:
?
O Digital meter reads in degrees of subcooling. ATOG used a margin to saturation which varies in the number of degrees of subcooling with the plant pressure. The operator cannot tell 3 when the plant has entered the margin. Reliance on this meter will cause operator overload and is prone to error during abnormal transients. i i RESOLUTION: Although the meter does not allow for the approximately 50 degrees F margin for cumulative errors'that is allowed on the SPDS, it still provides a good reference for the operator in relation to the saturation curve. The SPDS information will also be in direct view. The saturation meter is also used while throttling high pressure ir 4 ection to adjust the rate of flow. It is well situated to support this operation. l l O A-104 s-l
l d HUMAN ENGINEERING DISCREPANCY D-001 COMMENT: High Pressure Injection: Difficulty in viewing primary plant indications from 2Cl4L. LOCATION: Indicators on 2Cl2. DESCRIPTION: During emergency operations, an operator throttling high pressure injection valves from 2C14L or 2C14R nust look to 2Cl2 for pressure and temperature indications. RESOLUTION: When throttling injection flow, either high pressure or low pressure injection, the flow is of prime importance. Flow instruments for both systems are located with the controls on the Safeguards Panel (2Cl4). Effects on the primary para-meters change more slowly and can be easily monitored on the adjacent Primary Panel (2C12). These two panels meet at an angle of about 140 degrees, allowing the primary operator to easily view both panels with little movement. Throttling injection to control the primary parameters will be done iteratively over a period of time such that this operation will not place excessive demands on the operator. The most important primary parameter to be watched is the change in subcooling. This is clearly indicated on a digital neter and on the SPDS that can be read easily from the operating station at the Safeguards Panel. A-105
i l () HUMAN ENGINEERING DISCREPANCY E-023 i COMMENT: t Annunciator Relationships: Alarms are not clearly related to j the panel functions they are meant to draw attention to. 4 P LOCATION: ) 2C14, 2Cl2, 2C13, 2Cll, OCle, 2C15, 2C31 1 ] DESCRIPTION: i Annunciator alarms are located at the top of the panels and s are arranged in matrices of 25 to 70 alarm tiles. There is no direct means of relating the flashing alarm tile with an
; indication or control in the board.
1 i i i i i I 4 RESOLUTION: I 4 i Alarm matricies are .placed over the panel to which they relate. Windows within the matrix will be rearranged to j better relate them to the control panels underneath. l l O A-106
I HUMAN ENGINEERING DISCREPANCY E-019 COMMENT: Annunciator Alarm Interpretation: Alarms are difficult to identify and interpret. LOCATION: 2C14, 2Cl2, 2Cl3, 2Cll, OC10L, 2C15, 2C31 DESCRIPTION: Annunciator Tiles - Electro Devices Incorporated. Detection of change of state from nonilluminated to illumi-nated and vice versa is possible tp to 240 inches'at angles of incidence up to 60 degrees. Ann >2nciator horn and flashing code vill enable adequate detection from anywhere in front of the panels. Location coding of each tile on the panel would help identify the alarm function; however, reading of the legend is necessary to ensure complete and accurate transfer of annunciator information. RESOLUTION: Prioritize alarms and use standard terminology and font size to improve readability. O A-107
, HUMAN ENGINEERING DISCREPANCY E-022 a COMMENT: i j Annunciator Grouping and Relationships: Alarms cannot be quickly related to types of actions required. i l LOCATION: l 2Cl4, 2Cl2, 2C13, 2C11, OC10L, 2C15, 2C31 I d DESCRIPTION: O Annunciator Tiles - Electro Devices Incorporated. Location of Annunciator Panels away from all other components makes their illumination easy to detect. Ability to identify from individual tiles precisely which alarm has occurred is i more di f ficul t; this is because the arrangement of tiles on I panels is inconsistent for grouping of alarms by common sys-tems, common causes, or common response requirements. Of the tiles which are grouped, some are grouped horizontally and some vertically. No grouping of tiles by prioritization or l criticality is in evidence. Grouping of tiles is not obvious { either by line delineations or separation.
- RESOLUTION:
i All alarm windows will be rearranged in logical groupings and placed within the matrix to aid in relating them to the , control panels underneath. Some alarms will be moved to an l ajacent matrix in order to improve grouping. l l ! 1 A-108
HUMAN ENGINEERING DISCREPANCY E-025 COMMENT:
! Annunciator Alarm Priority: Annunciator alarms are not prioritized visually or audibly.
LOCATION: 2C14, 2Cl2, 2Cl3, 2C11, OCle. 2C15, 2C31 DESCRIPTION: Annunciators provide the same audio and visual displays for a wide range of alarms, alerts, and information signals that are not differentiated by importance or priority. RESOLUTION: Alarm windows will be prioritized by using red tinted windows for top priority alarms, yellow for intermediate priorities, and white for low priorities. Generally, top priority alarms will be near the top, low priorities at the bottom of the alarm matrix. l O A-109
HUMAN ENGINEERING DISCREPANCY ( E-017 COMMENT: Annunciators: Tiles seen to have a mirror image arrangement on the associated control panel. LOCATION: 2C14, 2C12, 2C13, 2Cll, OC10L, 2C15, 2C31 DESCRIPTION: Annunciator Tiles - Electro Devices Incorporated. Mirror image arrangement between Control Panels and Annuncia-tor Panels on the same console is unsatisfactory. The rela-tionships of annunciators to associated system components must be consistent. ( RESOLUTION: l f I Annunciator Panels have been enhanced with clear identification of system relationships. In no case is the annunciator, as enhanced, a mirror image of the actual panel arrangement. O A-110
HUMAN ENGINEERING DISCREPANCY E-027 COMMENT: Annunciators Legends: Panel summary tiles (i.e., those that signal an alarm condition on their respective panels) should be visually discriminated from tiles that signal an individual alarm. LOCATION: 2C14, OC10L DESCRIPTION: Split screen status indicators. Safeguards status displays. 1 RESOLUTION: Differentiation not required for intended use. O A-111
l l HUMAN ENGINEERING DISCREPANCY ( E-018 COMMENT: l Annunciators: Legibility of extinguished annunciator tiles is marginal due to their low contrast ratio. LOCATION: 2Cl4, 2Cl3, 2Cll, OC10L, 2C15, 2C31 1 DESCRIPTION: Annunciator Tiles - Electro Devices Incorporated.
)
Determine if it will be required to read extinguished tiles. RESOLUTION: Reading of extinguished tiles is not required. l lO 1 1 l A-112
i l
)
HUMAN ENGINEERING DISCREPANCY E-020 COMMENT: Annunciator Legends: Tile legends are inconsistent. LOCATION: 2C14, 2Cl2, 2Cl3, 2Cll, OC10L, 2C15, 2C31 DESCRIPTION: Annunciator Tiles - Electro Devices Incorporated. Annunciator tiles are dissimilar in (1) language and informa-tion (i.e., abbreviations, acromyns, terminology etc.) ; (2) type of information (e.g., mere identification of alarmed system, cause for alarm, required action, e tc.) ; and (3) i legend format (i.e., relative position of nomenclature, iden-tification number, action verb, etc.). RESOLUTION: Use standard terminology and format. O A-ll3
i i HUMAN ENGINEERING DISCREPANCY E-021 l l COMMENT: i Annunciator Unit 11andles: Individual alarm units have handles I that can obscure view of tiles from below. 1 i l i i l LOCATION: 4 } 2C14, 2C12, 2Cl3, 2C11, OC10L, 2C15, 2C31 1 1 4 DESCRIPTION: Annunciator Tiles - Electro Devices Incorporated. Ilandles used for removing each tile are not spring-loaded-to j retract. If they are allowed to remain extended, th3y obscure i the legend when viewed at angles of incidence exceeding 30 l degrees. l l l RESOLUTION: 3 ) Handles are spring loaded and will remain inserted if put in j this position. Not a discrepancy. i } i 1 !O l A-ll4
. - , - --.-- , - . , - . . - - . . - , , - , . , . . . , , - . . - . , , - - . , . . . - - . . _ . ~ , , . . . .,,-n. , ,..
HUMAN ENGINEERING DISCREPANCY E-024 COMMENT: Annunciator Audible Alarm. LOCATION: All control room Annunciator Panels, 2Cl4, 2Cl2, 2Cl3, 2Cll, OC10, 2C35, 2C15 DESCRIPTION: One audible frequency is used to sound for all control room alarms in both units. Intensity of sound, therefore, is the only reliable cue. At least three audible alarms, which are easily discriminable, should be employed: one for unit 1, one for unit 2, and one for the Common Panel OC10. RESOLUTION: There are 5 annunciator horns in the control room. Annunciator audible alarms can be adjustec in f requency and intensity. A human factors survey of alarm horn audibility will be conduc-ted when the control rooms are operational. O A-ll5
1 i () HUMAN ENGINEERING DISCREPANCY H-023 COMMENT: Annunciator Horn: There is no provision for silencing the norn without acknowledging all alarms on an individual panel. LOCATION: 2C14, OC10, 2C31 DESCRIPTION: During major accidents, a vast number of annunciator alarms O- may sound at various times, in effect causing a continuous set of unacknowledged alarms. This results in a continuous sounding of the horn while operators try to identify new alarms and consider the problems indicated. The continuous horn will be ineffective as an alert and will disrupt operator coordination. RESOLUTION: The capability exists to silence the horns at the annunciator logic cabinets located adjacent to the control room. Providing a total alarm silence feature might result in the horn being silenced when it should not be. The effects of the horns on operator senses will be evaluated as part of the environmental review when control room construction is complete. i A-116 l
HUMAN ENGINEERING DISCREPANCY H-033 COMMENT: Unit 1 Annunciator Panels: Annunciators for the turbine panel and secondary panel are switched. LOCATION: ICll DESCRIPTION: The location of these two panels have been exchanged during construction. This results in the secondary alarms being over the turbine panel and the turbine alarms being over the secondary panel. l RESOLUTION: The location of these two panels will be exchanged. O A-117
HUMAN ENGINEERING DISCREPANCY D-007 COMMENT: l ICS Crosslimit Alarm: Located on 2Cll far right annunciator over turbine panel. LOCATION: 2CllR DESCRIPTION: This alarm is a key indicator of instrumentation malfunction O and is of most importance to the secondary plant at It is difficult to observe this alarm f rom 2Cll(L) . 2C11(L). RESOLUTION: The ICS alarms will be relocated to the appropriate . panel above the secondary controls. 1 A-ll8
HUMAN ENGINEERING DISCREPANCY D-013 COMMENT: l ICS Alarms: Only two summary alarms are provided on annunciator panel. LOCATION: 2C11R DESCRIPTION: There are several alarm conditions of the Integrated Control System that are summarized in these two alarms. The operator must be able to identify which particular condition exists. RESOLUTION: Separating the ICS alarms to better indicate the particular alarm condition is being evaluated. Included in the evaluation is determination of the best method for presenting ICS alarm information. O A-119
l HUMAN ENGINEERING DISCREPANCY E-054 i COMMENT: Bailey Meter: Legends are not consolidated, character size and font not standard and inadequate for required viewing
- distances. Pointer location and graticules not optimally j arranged.
A i LOCATION: 2C14, 2Cl2, 2Cl3, 2CllL DESCRIPTION: l Vertical Meters - Bailey Meter Company, Type RY1200 and RY2220 s Edgewise Indicator (single and dual movement) . Legend identifying the measure is located at the bottom of the display on the scale. Function of the meter is labeled at the } top and in larger characters. The two are not visually associated. l RESOLUTION: Legends and labels will be improved consistent with overall panel enhancements. Pointer location and graticules, although not meeting strict human factors criteria were considered acceptable for intended use. 1 O A-120
HUMAN ENGINEERING DISCREPANCY E-118 ) COMMENT: Bailey Meters Fail Mid Scale: The mid scale position on most meters is a normal operation reading. LOCATION: 2Cl2, 2C13, 2Cll DESCRIPTION: Bailey Meter Company, Type RY3200 and RY2200 Edgewise Indicators use +10v to -lev range with Ov at nid scale. Since a mid scale reading could be a normal reading, operators may not detect a meter failure and believe the reading is steady. RESOLUTION: All Bailey meters will be marked with a red line at mid scale to alert the operator to check other indications when the meter is steady at mid scale. This meter is not used on safety systems. It uses NNI-X power and there is an alarm for the loss of NNI-X power. There are backup indications for all critical parameters. O A-121
< l 1 i HUMAN ENGINEERING DISCREPANCY E-069 l i l ! COMMENT:
- i 1
] International Instruments Meter: Legend is aligned vertically
- (i.e., one legend above the other).
1 e j LOCATION: 1 4 j 2C31 1 i l j DESCRIPTION: i
- Vertical Meters - International Instruments, series 1251 Dual Indicator.
I J i
! RESOLUTION:
Vertical legends are limited to abbreviated units of measure and considered acceptable for intended use. i i i 4 i i i A-122 d
HUMAN ENGINEERING DISCREPANCY E-070 COMMENT: International Instruments Meter: There is no discrimination between major and intermediate graticules. LOCATION: 2Cl4, 2C31 i l DESCRIPTION: Vertical Meters - International Instruments, series 1251 Dual Indicator. RESOLUTION: Since the control room was incomplete at the time this indicator was reviewed, the comment was generated as a result of examining photographs of like components. In actuality, the indicators installed do have acceptable graticule graductions. l O A-123
HUMAN ENGINEERING DISCREPANCY R-022 (} i i j COMMENT: Digital Meters: Some meters remain active when the parameter is outside their indicating range. i i 1 LOCATION: 2C24, 2Cl2/22, 2C13, 2Cll/21, OC10 i 1 DESCRIPTION: I J l Digital meters should indicate in some way that the reading is l "o f f-scale" . t i d i 1 ! RESOLUTION: i a I
- Reactor coolant average temperature (520-620 -degrees F) and j pressurizer narrow range pressure (0-600 psig) are the only j parameters with digital indications which are operated outside
- their ranges during routine operations. Methods of indicating
] to the operator that these indications are out of range are , being evaluated. l 4 O ~ A-124
HUMAN ENGINEERING DISCREPANCY E-037 COMMENT: Digital Meters: Meters do not provide qualitative information that is needed to diagnose problems. LOCATION: 2Cl4/24, 2Cl2/22, 2C11/21, CClC/20 DESCRIPTION: Digital meters provide primarily quantitative information, while analog meters provide primarily qualitative information. Most of the interacting systems within the plant require qualitative diagnosis in abnormal transients in order to diagnose specific problems. l RESOLUTION: l l Digital meters provide non safety grade indications of variables that change slowly, such as tank levels or variables needed to assess the status of plant equipment. The task analysis has shown sufficient analog instrumentation, includ-ing recorders where necessary, is provided to allow the oper-ator to diagnose and correct plant upset conditions without excessive reliance on the digital meters. Use of the digital meters in the applications chosen is not a discrepancy. A-125
d HUMAN ENGINEERING DISCREPANCY E-038 (} COMMENT: l s I Digital Indicators: Different sizes and color of displays are , used. i LOCATION: 2C13, 2CllR, 2C15 j DESCRIPTION: 4 Digital Indicators - Data Tech Incorporated, LED, red. ANALOGIC Incorporated, LED, red. George Instrument Company, LED, green. i The size and color of this display has no significant meaning, yet other similar type displays are larger. The size anc color could be interpreted as a code by the operator. 'The i inconsistency in size and color is not considered detrimental to operator performance; however, all same style digital displays would be desirable if the option is available, j RESOLUTION: I Two types of digital indicators are used: one has green numbers, the other red numbers. There is no meaning i associated with the two colors. Discussions with operators i indicate that no confusion will result. The two colors are
- considered satisfactory.
A-126
HUMAN ENGINEERING DISCREPANCY E-039 l l COMMENT: Digital Indicators: Terminology and legends are inconsistent. LOCATION: 2C13, 2CllR, 2C15 DESCRIPTION: Digital Indicators - Data Tech Incorporated, LED, red. ANALOGIC Incorporated, LED, red. George Instrument Company, LED, green. Legend language (abbreviations, terminology, etc.) is inconsistent with other indicators of the same style. Legend font and character size is inconsistent between indicators, l RESOLUTION: Use standard terminology, legends and fonts. l O A-127
! e I ) l HUMAN ENGINEERING DISCREPANCY E-045 l COMMENT: Digital Indicators: Manufacturer's logo "LPE" should not be visible on the front of the display. i LOCATION: ! 5 All panels except 2C23, 2C22, 2C15, 2C31. DESCRIPTION: } Dirjital Indicators - George Instrument Company, LED, green. 1 I RESOLUTION: Company logos do not interfere'with meter function. l O i i A-128
HUMAN ENGINEERING DISCREPANCY E-048 COMMENT: Digital Indicators: Rows of meters are difficult to differen-tiate. LOCATION: All panels except 2C23, 2C22, 2C31. DESCRIPTION: Digital Indicators - Data Tech Incorporated, LED, red. ANALOGIC Incorporated, LED, red. George Instrument Company, LED, green. Digital indicatore tend to be symmetrically or matrix arranged (i.e., rows and columns) since they easily lend themselves to this installation. Unless functions are similar, this arrangement provides a deceptive appearance of commonality among certain components. Separation and/or line delineations are requiced to prevent this deception. RESOLUTION: Swap components as required and enhance. O A-129
HUMAN ENGINEERING DISCREPANCY E-049 COMMENT: Digital Indicators: Labels are obscured. LOCATION: All panels except 2C23, 2C22, 2C31. DESCRIPTION: Digital Indicators - Data Tech Incorporated, LED, red. O ANALOGIC Incorporated, LED, red. George Instrument Company, LED, green. The location of labels above and close to the indicator causes them to be obscured when viewed f rom below at greater than 30 degrees angle of incidence. RESOLUTION: Labels will be placed above digital meters so that they may be viewed f roi.1 below. (o A-130 l
HUMAN ENGINEERING DISCREPANCY E-047 COMMENT: Watt Meter Reading: Cannot be easily compared with reactor power. LOCATION: 2C11R l DESCRIPTION: Matching generated power to percent primary system power on 2Cl3 requires a trans fo rma tion from generated megawatts ( 2C11R) to percent generated megawatts. RESOLUTION: I 1 i Change in efficiency in the secondary cycle precludes direct comparison between reactor power and generated negawatts. l l l l 9 A-131
I l H-031 O HUMAN ENGINEERING DISCREPANCY COMMENT: Condenser vacuum Indicators: Vacuum is calibrated in absolute pressure. LOCATION: 5 2011 _ DESCRIPTION: 1 Vacuum is normally indicated in inches of mercury rather than O pounds per square inch absolute. This is a possible source of operator confusion, i j RESOLUTION: i The condenser vacuum indicators will be recalibrated in inches o f Hg . d O A-132
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HUMAN ENGINEERING DISCREPANCY H-028 COMMENT: Steam Generator Thermocouples: Shell thermocouples.are read only on the computer. , LOCATION: Computer Display. DESCRIPTION: There should be a backup capability to read thermocouples in the event of a computer failure. These readings are required to prevent damage to the steam generators during cooldown. RESOLUTION: Steam generator shell temperature thermocouples are availabla in the plant computer. In the event of computer failure, this information can be obtained at the computer terminations adjacent to the control room. As steam generator shell temperature is required only during cooldowns, the backup method of obtaining this data is considered acceptable. O A-133
HUMAN ENGINEERING DISCREPANCY E-067 COMMENT: Foxboro, Meter: Legend identifying tne function is at the top l of the display. There is no legend identifying the measure. Logo should not be visible on the front of the meter. LOCATION: 2Cll, 2C21R, OC10R DESCRIPTION: O Vertical Meters - Foxboro, set point meter (black pointer, set point control). RESOLUTION: { I i Use standard consolidated grouping at top. Logo is small and not distracting. l O l A-134 L __ - _ _
HUMAN ENGINEERING DISCREPANCY E-064 COMMENT: Foxboro Meter: Legend identifying the function is at the top of the display. There is no legend identifying the measure. Logo should not be visible on the front of the meter. LOCATION: OC20R, 2C21R DESCRIPTION: Vertical Meters - Foxboro, level meter. RESOLUTION: Use standard legend grouping at top. Logo is small and not distracting. O A-135
HUMAN ENGINEERING DISCREPANCY E-076 (} COMMENT: Tap Changer Position Indicator: Contrast ratio between black characters and gold background at 45 degrees is marginal. LOCATION: 2C15 DESCRIPTION: O Dials (Circular or Curved) - General Electric, 4 inch circular scale meter. Westinghouse, 4 inch circular scale meter. RESOLUTION: Since tap changers are used for infrequent, minor adjustments, during normal operation, and not at all during emergency operations, their operation is deliberate with no stress. Scales on these meters are easily readable for the function they must perform. These meters are not the primary feedback for tap changer position. O A-136
HUMAN ENGINEERING DISCREPANCY E-081 COMMENT: Bailey Strip Chart: The function legend is at the top and the measure legend at the bottom next to the word " RED". This requires the operator to look at three different areas of the display for information. LOCATION: 2CllL, 2C22 DESCRIPTION: Recorder Indicators - Bailey Meter Company, vertical roll strip chart. RESOLUTION: Use standard labeling. 1 I l l O A-137
f () HUMAN ENGINEERING DISCREPANCY E-082 COMMENT: Bailey Strip Chart: Graph size may be inadequate to accommodate viewing distance. LOCATION: 2C22 DESCRIPTION: O Recorder Indicators - Bailey Meter strip chart. Company, vertical roll I RESOLUTION: These are used on back panels to record long-term trends. The observer will stand immediately in front of the graph to read it. No viewing distance is required. Graph size is adequate. O l A-138
HUMAN ENGINEERING DISCREPANCY E-083 l} COMMENT: Strip Chart: Records 15 functions by stamping numbers 1-15 on a recording paper. Numbers are difficult to read and are frequently stamped one on top of another. There are no inter-mediate or minor graticules. Detailed measurement can be read from graph. LOCATION: 2C21, 2C22 DESCRIPTION: Vertical roll strip chart. This Honeywell recorder appears to be an adequare recorder for later examination by engineers and for record purposes. It is extremely difficult to read and interpret under operational pressure. RESOLUTION: These recorders on the back panels are used to identify abnormal trends for various turbine parameters during normal operations. They are not intended for use during high stress transients. They are considered to be adequate for the use intended. O A-139
MUMAN ENGINEERING DISCREPANCY E-084 O COMMENT: Speedomax Recorder: Determine if reading graph is adequate to accomplish required tasks. LOCATION: 2C21, 2C23 DESCRIPTION: Vertical Roll Strip Chart - Leeds and Northrup, Speedomax O Recorder. There is a double set of scales, one above and one below the numeral, even though the pointer only points to the lower scale. This does not affect legibility of the display. I RESOLUTION: Closer inspection of the recorders revealed that there is a pointer for each scale. These recorders on the back panels are used to identify abnormal trends for various turbine parameters during normal operations. They are not intended for use during high stress transients. They are considered to be adequate for the use intended. . O A-140
HUMAN ENGINEERING DISCREPANCY E-085 COMMENT: Bailey Switch / Light: Legend character size is inadequate for the required viewing distance. LOCATION: OC10R, 2Cl3 l l DESCRIPTION: Actuator Indicators - Bailey Meter Company, Type RZ 030300, RZ 131312, RZ 333000 Switch / Light Station (OC10-98). l RESOLUTION: l Task analysis indicated that operation of these switch / lights is limited to their immediate location, therefore viewing distance is adequate. O ! A-141 l
E-073 O HUMAN ENGINEERING DISCREPANCY _ COMMENT: Synchroscope: GE logo should not be visible on the display. LOCATION: 2C11R, 2C15 DESCRIPTION: Dials (Circular or Curved) - General Electric, synchroscope. O l 1 RESOLUTION: Logo is very small and not distracting. O A-142
HUMAN ENGINEERING DISCREPANCY E-074 COMMENT: Synchroscope: Scale indication / operation. LOCATION: 2CllR, 2C15 D,ESCRIPTION: Dials (Circular or Curved) - General Electric, synchroscope. If the task requires operator action within a specific range (i.e., number of degrees) from tor dead-center, a scale should be provided to indicate this range. RESOLUTION: The synchroscope is widely used throughout the utility industry and has proven to be suitable. All operators are thoroughly trained in its use. O A-143 _ _ . - _ _ _ _ _ _ -__ -J
i HUMAN ENGINEERING DISCREPANCY E-068 a COMMENT: 1 Turbine Status Meters: Legend is aligned vertically (i.e., one letter over the other) . i i j LOCATIGN: i 2C11L 1 l DESCRIPTION: j Vertical Meters - General Electric, turbine status meters j (2Cll-31, 32, 120, 121). i 1 l l i I i RESOLUTION: 1 l These scales indicate valve position from 0 to 100 percent i open. Percent is displayed vertically alongside the scale and
- is in compliance with standards.
l l O A-144
HUMAN ENGINEERING DISCREPANCY E-050 COMMENT: Electric Control Ammeter: Intermediate graticules are the same size as major graticules. LOCATION: 2C12, 2CllL, OC10L, 2C21R, 2C14R DESCRIPTION: Horizontal Meters - General Electric, AC Ammeter. I RESOLUTION: These ammeters are associated with motor controllers and are used to observe starting currents and normal range current. They are required only for gross indications. This is not a discrepancy. l A-145
l l HUMAN ENGINEERING DISCREPANCY E-051 COMMENT: 4 Electric Controls Ammeters: GE logo should not be visible on the f ront of the display. i f i 4 LOCATION: 2C24, 2Cl2/22, 2CllL, OCl3L, 2C21R, 2C15 i DESCRIPTION: Ilorizontal Meters - General Electric, AC Amneter. 4 i f i J RESOLUTION: 3 Logo is very small and not distracting, !O l l A-146 l
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HUMAN ENGINEERING DISCREPANCY E-052 COMMENT: Electric Controls Ammeters: Legend character size is inadequate for the required viewing distance and inconsistent between meters. LOCATION: 2C24, 2Cl2/22, 2CllL, OC10L, 2C21R, 2C15 l DESCRIPTION: Horizontal Meters - General Electric, AL Ammeter. l l RESOLUTION: 1 These ammeters are associated with motor controllers and are used to observe starting currents and normal range current. They are required only for gross indications. This is not a discrepancy. l i A-147
i f i HUMAN ENGINEERING DISCREPANCY E-006 t
- COMMENT
1 Control Air Compressor: No trip indications. 4 I 1 1 ! LOCATION: j OC10 l t i DESCRIPTION: ] The control air compressor does not indicate tripped. 1 l RESOLUTION: ! The instrument air compressor is alarmed on the common panel annunciator located over the controls for the air compressors and status indication lights are provided above the control. l This HED is not considered to be a discrepancy. O A-148
HUMAN ENGINEERING DISCREPANCY A-009 COMMENT: The large size of this display is not warranted. LOCATION: 2C11n, 2C15 F DESCRIPTION: Dials (circular or curved) - General Electric, synchroscope. RESOLUTION: The larger size display is not considered detrimental to operator performance. l t O l A-149
() HUMAN ENGINEERING DISCREPANCY A-020 COMMENT: There is an expanded scale for AC amperes. LOCATION: 2C21 a DESCRIPTION: O Dials (circular or curved) - SCI Controls Incorporated, curved scale AC ammeter. Millivac Incorporated, curved scale millivoltmeter. RESOLUTION: This indicator was further reviewed and determined to be adequate for intended use. !O
- A-150
HUMAN ENGINEERING DISCREPANCY H-030 h COMMENT: Letdown Temperature Meter Scale: The scale is too wide range to be read accurately. LOCATION: 2Cl2 l l DESCRIPTION: l The O to 200 degree range is too wide for the very small operating range. It will be difficult to read and may result in damage to equipment. l RESOLUTION: There is an alarm on high letdown temperature and the system isolates automatically to protect the purification resins. No operator actions are based solely on the indication of this meter. Due to operational considerations, the range scale is considered adequate. O A-151
i HUMAN ENGINEERING DISCREPANCY H-011 i i COMMENT: I
! Pressurizer Pressure Recorders: Scale mulitpliers to be used in scale readings do not meet viewing distance requirements.
There are no units indicated. Different multipliers are used for the scales and the chart paper. 4 LOCATION: 2Cl2 1 i
- DESCRIPTION
- Although the two recorders have the same upper limit, the
! graph paper and fixed scales read variously 25, 250, and 2500 j for that upper limit.
1 J I j RESOLUTION: Chart paper will be provided to match the indicating scale. O A-152
. - _ - - . _ _ _ . . . . . _ _ . - . - ., . - . . . - . _ _ _ n.. . . . - .
l 1 9 i i i i 1 i t
!' I l
l i ' ! DEDICATED PANELS . 1 e t l ( i l 1 l 1,
4 l i j HUMAN ENGINEERING DISCREPANCY O-002 i i l l 5 COMMENT: ! Split Screen Indicators: The terminology "NOT MANUALLY BYPASSED" is ambiguous and should read in a positive state. 4 i I LOCATION: 1 i
- 2C14, OC10L l
l DESCRIPTION: ) ! Split screen status indicators safeguards status displays. 1 l l l l ). RESOLUTION: , The legend will be changed to " READY". ,
- A-153 w--. c - ._., ,+- __ - - - - . , - -, , #-,.-,,---,--w wm . -- -
HUMAN ENGINEERING DISCREPANCY E-028 COMMENT: Safeguards status lights: Lights are arranged in rows for ease of scanning but some rows have blank indications that will not light on actuation. LOCATION: 2C14 DESCRIPTION: Lights are arranged in rows so that they present a continuous "bar" of light when the system actuates properly. The operator monitors the status lights by exception: only the light not on, appearing as interruptions in the light bar, require his action. Yet those lights not used (Blanks) will also appear as interruptions, incorrectly alerting the operator to a malfunction. RESOLUTION: Spare lights, which interrupt the continuity of the bars, will be continuously lit. O A-154
- _ _ _ _ . . _ . .- - . = .- ._
l l 1 HUMAN ENGINEERING DISCREPANCY E-026 ( , COMMENT: Split Screen Indicators: Grouping is inconsistent.
- LOCATION:
2C14, OC10L DESCRIPTION:
- Split screen status indicators.
s Safeguards status displays (OC10L, 2Cl4). Functional grouping of lights is inconsistent. Some are grouped by row and some by columns. Location coding is not utilized to its fullest benefit in the arrangement of displays. RESOLUTION: 1 Enhance screen groups and use hierarchical labeling. ) l O A-155
)
HUMAN ENGINEERING DISCREPANCY E-029 lg COMMENT: Split Screen Indicators: Too much information on screens. Affixing a common label and delineation lines to those displays that are grouped will reduce the amount of informa-tion necessary on each legend. LOCATION: 2C14, OC10L DESCRIPTION: Split screen status indicators. Safeguards status displays. g RESOLUTION: Use hierarchical labeling and standard terminology. 1 A-156
() , HUMAN ENGINEERING DISCREPANCY E-030 COMMENT: Split Screen Indicators: There is inconsistency in the legend for.na t and content. i I l LOCATION: 2C14, OC10L DESCRIPTION: O Split screen status indicators. Safeguards status displays. Poor spacing of legends on the screen prevents all characters from being readable. Portions of some characters are obscured by the bezel. Some legends are located on the split making them illegible when both screens are extinguished or only one screen is illuminated. Many indicators nave four lines of characters, two lines on each screen. Similar type information should always appear at the same location within the legend. RESOLUTION: Use hierarchical labeling and standard format. O A-157
i l HUMAN ENGINEERING DISCREPANCY E-334 h COMMENT: S pli t Screen Display: Screens do not appear to conform to color codes. LOCATION: 2C14, OC10L DESCRIPTION: White illumination implies system " readiness" or " automatic" operation. Yellow denoted only that an automatic safeguards functilon has occurred. The exact state of the function (i.e., CLOSED, OPEN, etc.) m .s t be read from the legend. RESOLUTION: Panel indicates improper line-up by exception. This is not considered a discrepancy. l I A-158
() HUMAN ENGINEERING DISCREPANCY E-035 , COMMENT: Spli t Screen Indicator: Screen legibility. LOCATION: 2C14, OC10L ! DESCRIPTION: O Split screen status indicators. Safeguards status displays. When the white screen is extinguished, a low contrast ratio produces poor legibility of the white screen legend. The yellow screen legend is readable even when the yellow screen is extinguished. Proposed operation of this indicator assures that all portions of the indicator will be sufficiently legible during its normal operation cycle. RESOLUTION: Improved labeling will reduce the number of lines of information on the display and increase label size thereby improving readability. O A-159
HUMAN ENGINEERING DISCREPANCY E-003 h COMMENT: Core Map: Numbering convention. LOCATION: 2Cl3 DESCRIPTION: Rod numbers on the core map do not correspond to group / rod numbering convention. When latching, one must select the rod number on the core map and transform that number into the corresponding group / rod number. RESOLUTION: A core map overlay will be provided that indicates the group arrangement and numbers the rods within each group. O A-160 J
HUMAN ENGINEERING DISCREPANCY E-002 COMMENT: Rod Control Panel: Panel arrangement is confusing and therefore could contribute to operator error. LOCATION: 2Cl3 benchboard. DESCRIPTION: The functions and relationahips on this panel are not O arranged and difficult to understand. well RESOLUTION: This panel is used during routine operation (i.e., s ta r tup) only. There is no stress associated with operation of this panel. The panel design was considered acceptable with the exception that panel indicating light colors will be changed to conform to control room standards. A-161 1 A . . . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ J
HUMAN ENGINEERING DISCREPANCY E-004 COMMENT: Rod Control Panel: Color conventions incorrect. LOCATION: 2Cl3 DESCRIPTION: This panel used indicating light color conventions not in conformance with the rest of the panels. RESOLUTION: Indicator light colors will be changed to conform with control room conventions. l O l A-162
HUMAN ENGINEERING DISCREPANCY H-014 (} COMMENT: Steam Generator Isolation Control (MSLIS) : Lights are exces- , sively large and bright. Labels are obscured by the size of ; the lights. Color of backlit actuator is not IAW color convention. i LOCATION: 2C14 i DESCRIPTION: O This is a commercial panel that uses very large lights for-indicating and for actuation / indication pushbuttons. lights are far larger and brighter than other indications on both The ' the panel. Because of the size of the lights, some labels cannot be read without bending down. l RESOLUTION: t This operating panel will be modified to reduce light intensity, make labels easier to read and change lens covers to conform with control room standards. l l l 1 () A-163
HUMAN ENGINEERING DISCREPANCY P-007 COMMENT: FOGG Bypass: During cooldown with a ruptured steam generator tube, there is no provision for simutaneously feeding both steam generators with a dif ferential pressure of greater than 40 lbs. LOCATION: 2C14 DESCRIPTION: During plant cooldown with an isolated steam generator with a ruptured tube, the differential pressure between steam generators will exceed 43 lbs. This will actuate FOGG, which will allow feeding only one generator, blocking the other. There will be times in the cooldown when both steam generators must be fed. I RESOLUTION: Switches which bypass FOGG to allow simultaneously feeding of both steam generators will be provided. i I A-164
HUMAN ENGINEERING DISCREPANCY P-008 ( COMMENT: Main Steam Line Isolation (MSLIS) Bypass: During cooldown with a ruptured steam genera tor tube, there is no provision for bypassing MSLIS with the bad steam generator still at an elevated pressure. LOCATION: 2Cl4 l l DESCRIPTION: In order to prevent MSLIS actuation during plant cooldown both O\ steam generators must be in a 55 psi window between 670 and 775 psig. With one generator having a ruptured tube, both steam generators cannot be within this window. Actuation of MSLIS isolates the steam generators and interrupts the CooldoWn. RESOLUTION: The MSLIS bypass logic will be redesigned to allow the bypass to be put into effect with only 1 steam generator less than 725 psig. The bypass will be automatically removed if the pressure in both steam generators exceeds 725 psig. O A-165 l
HUMAN ENGINEERING DISCREPANCY H-017 COMMENT: Power Operated Relief Valve: The switch for the PORV is spring return to close. LOCATION: 2C31 DESCRIPTION: During operations when the PORV must be open for long periods to maintain core cooling in emergency conditions, an operator must hold the switch open. RESOLUTION: The PORV control will be changed to a maintained contact switch. O A-166
HUMAN ENGINEERING DISCREPANCY P-009 l COMMENT: , Core Flood Tank Isolation Valves: After the Emergency Core Cooling system has actuated, the core flood tank isolation valves cannot be returned to manual control without resetting other safeguards systems. , LOCATION: ) 2C35 i DESCRIPTION: i l' Following actuation of Emergency Core Cooling, the core flood tanks may empty and the isolation valves must be shut to prevent the nitrogen charge from entering the primary. In order to close the isolation valves after ECCAS actuation, the system must be bypassed at 2C35. The only pushbutton provided 4 will also reset the BWST automatic shift to sump recircu-i lation. i 4 3 RESOLUTION: l The input to the automatic switchover from BWST to SUMP (RAS) will be relocated individually on a AUTO / MANUAL pushbutton, ! separate from all other functions. This will allow other functions to be restored to manual control without removing 1 the enable to the RAS circuitry. l A-167 i
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HUMAN ENGINEERING DISCREPANCY H-001 COMMENT: Steam Generator: Operating level. LOCATION: 2C21 DESCRIPTION: Steam generator operating range level is only provided on the back panels. This is the only temperature compensated level provided and is referenced frequently during both normal and emergency conditions. RESOLUTION: Steam generator operate range level will be relocated to the front of the Secondary Panel (2Cll). O A-168
HUMAN ENGINEERING DISCREPANCY D-019 I COMMENT: Steam Generator Level Recorder: It would be useful to have a recording of steam generator level on the front panel. LOCATION: l 2Cll DESCRIPTION: There are recorders on the secondary back panel for steam O generator level, but not on the front panel. recent level conditions. history is useful to the operator during upset A recording of RESOLUTION: Relocation of the Steam Generator Level Recorders to the front panels is being evaluated. There are space constraints involved due to size of recorders. O A-169
1 HUMAN ENGINEERING DISCREPANCY H-034 COMMENT: Feed Flow Recorder: Feed flow trend information not provided on front panel. LOCATION: 2C21 DESCRIPTION: Trend information on this parameter is used to diagnose plant conditions during transients. RESOLUTION: Relocating a trend recorder on the front panel is currently being evaluated. O A-170}}