ML20214E308

Forwards Descriptions of Safety Significant Human Engineering Discrepancies (Heds) Identified During Dcrdr,Per Commitments Made in Util Comments on Draft Ser.Justification for Heds That Will Not Be Addressed Also Encl

ML20214E308
Person / Time
Site:	Davis Besse
Issue date:	02/28/1986
From:	Williams J TOLEDO EDISON CO.
To:	Stolz J Office of Nuclear Reactor Regulation
References
1252, TAC-56116, TAC-65255, NUDOCS 8603070254
Download: ML20214E308 (14)

Text

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7' TOLEDO

% EDISON JOE WILUAMS. Jn.

Docket No. 50-346  % ,, .

[419}749 2300 License No. NFP-3 l " ' " 2#'

Serial No. 1252 February 28, 1986 Mr. John F. Stolz, Director PWR Project Directorate #6 Division of PWR Licensing-B United States Nuclear Regulatory Commission Washington, D. C. 20555

Dear Mr. Stolz:

Toledo Edison committed to provide descriptions of the safety significant Human Engineering Discrepancies (HEDs) identified during the Detailed Control Room Design Review, that were to be addressed prior to restart. This conmitment was made in our comments (Serial 1241) on the draft SER (Log 1914). Those descriptions are attached along with a justification for those HEDs which will not be addressed prior to rectart.

The Detailed Control Room Design Review (DCRDR) progran presented in the Davis-Besse Course of Action describes the program that will address the HEDs remaining after restart. All HEDs prioritized as medium safety significance in Serial No. 1121, dated January 31, 1985 will be resolved by the end of the next (fifth) refueling outage. All detailed Control Room Design Review (DCRDR) items will be completed by the end of the sixth

• refueling outage at which time all HEDs will be resolved.

Very truly yours,

/  :

9 JV:RRS:plf Attachment cc: DB-1 NRC Resident Inspector i

gRO3070254 860228 g6 p ADOCK 05000346 PDR - 8 i l 1

l THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO, OHIO 43652 i 1

Toledo Edison committed to a reevaluation of the priority of the 29 safety significant HEDs with input from the human factors specialists. This commitment was made verbally in a meeting between the NRC and Toledo Edison on October 9, 1985, and stated in writing in Appendix C.5.1 of the Davis-Besse Course of Action. The reassessment of the 29 safety signifi-cant HEDs has been completed with the specific support of a human factors consultant from the Essex Corporation.

The original prioritization of the 29 HEDs performed in November of 1984 and described in our January 31, 1985 submittal (Serial No. 1121) was based on engineering judgment and did not include input f rom the human factors specialist. The prioritization was based on the significance of the consequences of the errors which were assumed to occur for each of the 29 HEDs. The significance ranking given was as follows:

High - The hypothesized error will prevent or degrade a safety function.

Medium - The hypothesized error will challenge a safety system or could potentially degrade a safety function.

Low - The hypothesized error could potentially challenge a safety system.

The reevaluation which was performed with the aid of the human factors specialist, Essex, considered the conaequences of the error, but also considered those human factors aspects which could tend to improve or degrade the likelihood or consequences of the hypothesized error.

Independently, a review of systems important to safe plant operation was performed under the System Review and Test Program (SRTP). The SRTP has been described in Section II.C.7 and Appendix IV.C.7.1 of the Davis-Besse Course of Action. The reviewers in the SRTP were also supported by a human factors specialist as described in Appendix IV.C.5.1 of the Course of Action. This review was independent of the earlier prioritization efforts, and the SRTP reviewers were unaware of the results of the priori-tization reviews.

l The reviews performed by the SRTP were ong a system-by-system basis, and the HEDs reviewed were those of the 29 which had some direct applicability to the respective systems. Five of the 29 HEDs were, consequently, not reviewed as a part of the SRTP because the HEDs addressed controls or displays associated with systems outside of the program, or because the '

HEDs were associated with generic procedural problems, and not directly applicable to systems within the scope of the program. Three of these five are being addressed during this outage, and the remaining two are of very low safety significance.

The reprioritization review and the evaluation performed in conjunction with the SRTP has resulted in the development of corrective actions which will address all or portions of 14 of the 29 safety significant HEDs prior to restart from the current outage. Corrective actions for the three human factors related hardware problems which complicated the June 9, 1985 event have addressed three of the HEDs. These corrective actions have l

been described in the Course of Action and included the correction of the single high priority HED (HED #9.2-54) associated with the arrangement of the SFRCS manual actuation switches.

Prior to the June 9, 1985 event, one of the 29 safety significant HEDs had been corrected. Fourteen more are to be addressed during the current outage. Therefore, at least 15 HEDs will be fully or partially corrected prior to restart. Evaluations of potential corrective actions for at least two more HEDs are in progress and may be implemented prior to restart.

The review efforts have also generated proposed corrective actions to be implemented after restart. Some of these corrective actions will further address HEDs partially corrected during this outage, while other proposed modifications will address additional HEDs.

The plans for the addition of a new Control Room SFRCS panel and a major revision to the post accident monitoring panels are continuing and are expected to be completed during the next (5th) refueling outage. These changes will address six more of the 29 HEDs; and with the paint, tape, and label changes also to be implemented during the next refueling outage, will address all of the HEDs prioritized with a medium safety significance in the January 31, 1985 letter.

Following restart from the current outage, the special studies previously described in the DCRDR Summary Report and further defined in the Davis-Besse Course of Action will be performed. As described in the Course of Action, these special studies will result in the development and implementation of corrective actions for the remainder of the 29 HEDs categorized as low safety significance, and all other HEDs in the DCRDR during the next (5th) and following (6th) refueling outages.

The following is a listing of all 29 of the safety significant HEDs. The first 15 to be listed are those which will have been addressed prior to restart. The listing includes a brief description of the HED and the status of its disposition. For those HEDs which will not be addressed prior to restart or will be partially corrected, a justification for longer term correction is provided. The medium or low safety significance referenced in the justification corresponds to the significance classifi-cations described above.

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HEDs TO BE ADDRESSED PRIOR TO RESTART HE7 NO.

1.7-11 Component Light Bulb Replacement Indicator lights and pushbuttons have shorted out during bulb replacement. This is a potential problem on most panels in the Control Room.

This HED was not reviewed by the SRTP. As described in the January 31, 1985 submittal, this HED has already been fully corrected. The main cause of this problem was a metal bulb extractor which has now been replaced by a plastic extractor.

3.1-37 Multiple Inputs to Annunciators i Some Control Room annunciator alarm tiles display inputs from i more than one parameter.  !

This HED will be partially corrected before plant restart.

Several alarms with multiple inputs have been evaluated as nuisance alarms and will be removed before restart, thereby eliminating sources of multiple inputs to annunciator tiles.

Corrective actions for several other multiple input annunciators have been initiated, but will not be implemented during this outage. The remaining annunciator tiles described in this HED will be included in the Annunciator Study.

This HED has a low safety significance. As prescribed by the Station emergency operating procedure, there are no safety related operator actions associated with multiple input annunciators.

5.1-2 Positive Indication of Equipment Status Equipment status is indicated by an unlit display on several panels. This allows the possibility that a burned out bulb misrepresents actual equipment condition.

The addition of acoustic flow indication near the power operated relief valve (PORV) controls provides improved information on the status of the PORV position. Other displays mentioned in this HED will be examined af ter restart as a part of the Dis-plays Study.

This HED has low safety significance since hypothesized errors associated with this HED would not result in the degradation of a safety function, and since no safety related operator action is required on the basis of these indications alone. Other equipment status indications exist in the Control Room includ-ing, for example, alternate indication of valve positions, annunciators indicating abnormal equipment conditions, and Safety Features Actuation System (SFAS) status lights which ,

provide equipment status indication following SFAS initiation. '

Additionally, plant response to abnormal equipment conditions would initiate corrective operator action.

HEDs TO BE ADDRESSED PRIOR TO RESTART HED NO.

5.1-6 Scale Range The scales on some meters do not provide sufficient range for expected parameter values.

The makeup flow indicator will be modified prior to startup to provide a range sufficient to show flow value for two pumps running simultaneously.

Hypothesized errors associated with the remaining scales men-tioned in the HED are of a low safety significance and will be addressed as a part of the Displays Study after restart.

6.1-15 Components obscured by Labels Control panel components and labels are sometimes obscured by temporary labels, magnetic labels, information tags, and IaC stickers.

This HED was not reviewed as a part of the SRTP. This HED will be fully corrected by restart. A new Administrative Procedure, AD 1803.02, requires that information tags be "placed in such a way that they do not block other indicators, gauges, lights, etc." To facilitate this requirement for hand indicating switches, a plastic shroud will be used for placing information tags.

9.2-4 Temperature Control Selection: Control-Display Relationship The display of selected control temperature cannot be seen by the operator who is manipulating the selector control for this process.

This HED was not reviewed as a part of the SRTP. This HED will bo temporarily corrected by procedurally, removing the require-ment to manipulate this control selector switch. The process affects non-safety related controls which can, however, cause an upset to plant operating conditions and could potentially result in a reactor trip. The procedural requirement for periodically checking the redundant selectable instrument string has been temporarily removed, and the preferred instrument string align-ment will always be maintained. This correction, while tempo-rary, fully removes the HED. Permanent corrective action for this HED will be identified as a part of the Displays Study after restart.

9.2-6 Reset Pushbutton Mistaken For Trip Pushbutton The SFAS reset pushbutton has been mistaken for a trip pushbut-ton due, apparently, to its similarity to the reactor trip and turbine trip pushbuttons.

HEDs TO BE ADDRESSED PRIOR TO RESTART HED NO.

This HED will be fully corrected before plant startup. The similarity between reset and trip pushbuttons can be minimized with appropriate labeling. These pushbuttons are relatively high on the panel and the " RESET" label is partially obscured by the pushbutton below it (except for tall operators). This condition promotes the tendency to rely on the reset-trip shape similarity. This concern will be corrected by placing an additional " RESET" and " TRIP" label below the four pairs of pushbutton controls in order to provide a prominent identifica-tion of the trip and reset functions.

9.2-18 Identification of SFRCS Trips SFRC3 trips are difficult to identify as real or spurious.

SFRCS alarms do not discriminate between full or half trips.

The computer CRT will only display two of four possible trips.

1 j This HED will be partially resolved before plant restart. The logic to the SFRCS annunciator alarms has been modified to provide a dedicated annunciator window for the low pressure condition for each of the two steam generators. The logic has also been revised to prevent inadvertent clearing of the FULL TRIP annunciator. Other changes have been proposed to resolve the remainder of thin HED af ter restart. A complete review of this HED will be performed in the Annunciator Study. This HED has a medium safety significance. Other indications exist in the Control Room which can be used to identify the cause of the SFRCS trips although they are less efficient.

9.2-20 SFAS Incident Isolation Component Arrangements Two SFAS incident isolation groups have ambiguous component arrangements: (1) Reactor Coolant pump seal cooling components G

which receive Level 3 signals are located in a Level 2 group, and (2) Auxiliary Feedwater components are located in a Level 4 group even though they do not receive a Level 4 signal.

This HED will be fully corrected before plant startup with a temporary c.odification. This modification will visually high-light the affected controls to enable the operator to rapidly locate and recognize the components which are inappropriately  !

grouped. After restart, a permanent solution will be considered I in which control relocation and labeling design will be investigated.

9.2-28 Reliability of Feedwater Flow Indication

! A feedwater flow indicator can provide an erroneous reading which, in certain plant conditions, results in an overfilled steam generator. This is the result of the automatic transfer l from main to startup feedwater flow indication by a system l interlock.

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HEDs TO BE ADDRESSED PRIOR TO RESTART HED NO.

This HED will be fully corrected before plat.c restart. The interlock, which permits flow indication to be switched automat-ically to startup feedvater flow, has been removed such that the normal main feedwater flow is always used.

9.2-30 Reactor Coolant System Temperature Dispiny Visibility The wide range Reactor Coolant System T-hot and T-cold are not located together in a location easily visible from the front panel.

This HED will be partially addressed by the inclusion of these parameters on the Safety Parameter Display System (SPDS) which is visible from the front console. Further corrections for this HED will be considered in the Display Study after restart.

This HED has a low safety significance rating. The information is availabic in the Control Room and the task is not time critical.

9.2-42 Reliability of Steam Generator Level Indication Operators receive inconsistent indication regarding steam generator level from ICS, SFRCS, and the steam generator level j displays. Operators have reported that this condition has led

! to SFRCS actuation although the Control Room indication for SG i level was indicating an acceptable margin. This is the result <

i of differences in calibration and compensation of the various level indication and control input signals.

This HED will be partially corrected before plant restart. The setpoint for ICS control of minimum steam generator level has been increased to provide additional margin to the SFRCS low level trip. This will reduce unnecessary SFRCS actuations following a reactor trip when ICS control of minimum steam generator icvel allows a slight undershoot before stabic control is established. The new SFRCS panel will contain improved steam generator level displays to permanently address thir,llED.

9.2-43 Location of SFRCS Block Control An operator must leave the primary operating area in the Control Room and go to a back panel to access the startup feedwater valve SFRCS block control.

This HED has been fully corrected. The new Motor Driven Feed Pump provides a direct supply of feedwater to the steam genera-tors and removes the need for use of the startup feedwater block l control in the Emergency Operating Procedure. The startup feedwater valve block control has been moved to the primary operating area in the Control Room for other tasks when required.

HEDs TO BE ADDRESSED PRIOR TO RESTART HED NO.

9.2-47 HPI Symbol on ESF Mimic The ESF panel mimic depicts an ambiguous relationship between the Decay iteat (DH) pump control and the High Pressure Injection (HP1) pump control because the llP1 identification symbol is midway between the two controls. Also contributing to this concern is that the pump labels are partially obscured by the switch handle and both pump mimics are the same color.

This HED will be fully corrected with a temporar3 modification.

The modification, using labeling and other graphic techniques, will strengthen the association between the pump symbol and pump control and improve identification of the affected components.

After plant restart, this modification will be reevaluated in the Displays Study for coordination with other Control Room corrections.

9.2-54 Location of SFRCS Manual Initiation Switches The SFRCS manual initiation switches are inappropriately locat-ed. They are (1) arranged inconsistently, (2) separated from other SFRCS related controls and displays, and (3) too low on the vertical panel.

The first element of this llED has been fully corrected, and the third elenent has been partially addressed. The pushbuttons have been rearranged to eliminate the previous crossover ar-rangement and to allow an operator to rapidly locate the re-4 quired pushbutton control. The pushbuttons procedurally designated for manual actuation of the SFRCS have been moved to the top of the columns at an acceptable IcVel on the panel.

Covers have been placed over the Steam Generator 1 and 2 low

, pressure switches and steam / feed differential pressure switches

+

which are less frequently used to further reduce the potential for confusion.

The inappropriate placement of the SFRCS manual initiation switches with respect to other SFRCS controls and displays in of medium safety significance. This problem is also addressed in llED 9.2-1. Although the various components are not grouped together for convenient verification of control actuation, the information is available in the Control Room for verification, and system operation is not directly dependent on verification.

This element of this llED and llED 9.2-1 will be resolved by the installation of the new SFRCS panel which will centrally locate i

the required SFRCS components.

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HEDs TO BE ADDRESSED AFTER RESTART HED NO.

1.7-10 Component Light Bulb Reliability The majority of the indicator lights on the control board do not have lamp test capability, dual bulbs, or dual filament bulbs.

This could result in misinterpretation of equipment status, r

This llED will be resolved af ter plant restart. The displays indicated in this llED will be examined in the Displays Study.

This llED has a low safety significt.nce. A large number of indicator lights relevant to this HED have alternate status indication. For instance, in many cases of the pushbutton switches, a burned out bulb can be determined fairly easily because it is normal for the switch to always have an indicating light on. Also, the rotary switch handle or knob usually points to a labeled position. Equipment status can also be derived including, for example, alternate indication of valve positions, annunciators indicating abnormal equipment conditions, and Safety Features Actuation System (SFAS) status lights which provide equipment status indication following SFAS initiation.

Additionally, plant response to abnormal equipment conditions would initiate corrective operator action. It should be noted that annunciator tiles have multiple bulbs and are, thus, not included in this llED.

4.1-4 Component Grouping Demarcation A Makeup Tank hydrogen inlet valve has been inadvertently actuated instead of the intended makeup pump suction three way valve switch. This appears to be due to (1) unclear labeling and coding on the selection switch, and (2) the close proximity of the two switches. On the same panel, the pressurizer spray controls may be confused with the heater controls due to lack of clear grouping between these two sets of components.

l Potential corrections for this llED are being evaluated and may be fully corrected before plant restart. On the first problem, both switches could be provided with unambiguous label identifi-cation and the purge tank grouping could be emphasized with a new group label. The second problem may be corrected by provid-ing demarcation lines and group labels to clearly define the spray components and the heater components. This llED has a low safety significance since the control functions have automatic i backups and are not associated with safety-related actions. If i not corrected prior to restart, this llED will be addressed as a part of the Labeling Study after restart.

5.1-7 Recognition of Failed Meter An operator does not necessarily know when a meter fails because i the meter's pointer continues to indicate a mid-scale value.

The pointer should fail offscale.

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HEDs TO BE ADDRESSED AFTER RESTART HED NO.

This HED will be resolved after plant restart. The displays indicated in this HED will be examined in the Displays Study.

This HED has a low safety significance and applies only to non-safety related equipment. For expected failure modes such as power supply problems or fuse failures, alternative Control Room indications exist, and the operators have been trained to recognize and respond to those failure modes.

5.1-9 Hulti-scale Display Readability The multi-scale design of some meters makes them difficult to read the scale.

This HED will be resolved af ter plant restart. The displays indicated in this HED will be examined in the Displays Study.

This HED has been assigned medium safety significance. Although these components do not have an optimal scale design, the dual scale difficulty does not prevent the meter from providing its a function. Although the meters require extra care in reading the scale, the operator does not have to make guesses or assumptions i to make the observation.

5.1-29 Scale-Pointer Parallax 1 Meters on the Post Accident Monitoring Panel (PAM) are desige

with too much space between the scale and the pointer. This

results in parallax or difficulty in reading precise values on that display.

1 j This HED will be resolved af ter plant restart. As previously described, plans are already being developed to significantly modify the existing PAM panel. The modified panel will include new meters selected to avoid the parallax problem. This HED has i

a medium safety significance rating. The same information in a more precise format is availabic in the Control Room, although it is not centralized in one location.

6.1-12 Location of Component Identification tsbel Most component identification labels are not located above the components that they describe. This often results in the identification being covered during control activation.

This HED will be resolved after plant startup. The generic concern about label location will be considered with related concerns in the Labeling Study. This llED has a low safety significance rating. Most of the labels containing functional identification of the component are above the component. The information below the component generally is an alpha-numeric identifier which is usually used less frequently by the operator.

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HEDs TO BE ADDRESSED AFTER RESTART HED NO.

9.2-1 SFRCS Actuation and Verification: Control-Display Relationship Displays used to verify SFRCS actuation are located on different panels than the panel containing the actuation controls.

D This HED will be resolved af ter plant restart. This HED has a medium safety significance. Although the components are not located together for convenient verification of control actua-tion, the information is availabic for verification, and system operation is not directly dependent on verification. This HED will be resolved by the installation of the new SFRCS panel which will centrally locate the required SFRCS components.

9.2-5 ICS Channel Selection: Control-Display Relationship Four ICS channel selector switches are located near meters not directly related to the selector switch function. This condi-tion appears to have contributed to errors in using these switches.

Potential corrections for this HED are being evaluated, and it may be fully corrected before plant restart. In two cases where the adjacent display is not directly reinted to the control, the control and display may be separated by a demarcation line. In the other two cases, mimic lines may associate the related control and display. In each case, the selector function of the switch could be emphasized by the addition of symbols to repre-sent computer input as a source to be selected. This HED is of low safety significance applying only to non-safety related components; and if not completed prior to restart, will be addressed as a part of the Label and Locations Aids Study. If this modification is completed prior to restart, it will be re-examined for consistency with existing and/or new graphic conventions as a part of the Labeling Study.

9.2-7 Scale Accuracy For Auxiliary Feedwater Flow The scale for auxiliary feedwater flow on panel C-09 is not sufficiently accurate for operational use. This in the result of inaccuracies in the instrument string itself.

This HED will be resolved af ter plant startup. Proposed modifi-cations have already been developed to address this concern.

These plans will be coordinated in the Display Study which has criteria directed to scale design and accuracy. This HED has a low significance rating. Auxiliary Feedwater flow is available in other forms in the Control Room. Aside from the main panel indication addressed in the HED, an additional safety grade indication of Auxiliary Feedwater flow is available on the PAM panel. This indication is more accurate than the non-safety grade instrument referenced in the HED, but is less conveniently located. The indicator itself suffers from the parallax prob-lems addressed in HED 5.1-29.

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l HEDs TO BE hDDRESSED AFTER RESTART HED NO.

l Auxiliary Feedwater flow indication 19 also available on the l Plant Process Computer and the Safety Parameter Display System.

l These indications are both more accurate and are more conve-niently located, but require additional operator action to use.

Most importantly, the operator has other indications of proper Auxiliary Feedwater System operation in the Control Room through readily available displays of other system parameters. Steam Generator level and pressure and primary system pressure provide direct indication of the status of Auxiliary Feedwater flow. ,

9.2-33 Spatial Relationship of Auxiliary Feedvater Components The displays and indications supporting Auxiliary Feedwater System operation are not centrally located which complicates the task of verifying system operation. The distribution and sequential relationship of the Auxiliary Feedwater components is confusing and can result in difficult verification of the system operation.

This HED will be corrected following restart in conjunction with the new SFRCS panel. This HED is of medium safety significance.

Although the distribution of Auxiliary Feedwater System controls and indications complicates the task of verifying system opera-tion, the information is available in the Control Room, and proper system operation is not dependent upon verification. As discussed in the previous HED 9.2-7, proper operation of the Auxiliary Feedwater System can also be verified using other prinary and secondary system indications.

9.2-65 Main Turbine control and Stop Valve Status Indication The indication of the Main Turbine Control and Stop Valve status in the Control Room is unreliable. Thin is actually a design /

maintenance problem associated with the instrumentation sensor in the field which can result in inaccurate Control Room indica-tion. This could result in a delay of determining equipment status.

The sensor problem is currently being evaluated to determine the feasibility of short tr.rm corrective actiots. If these correc-tive actions cannot be implemented prior to restart, this HED will be addressed in the Displays Study af te r restart.

It was not addressed as a part of the SRTP. This HED has low safety significance and is not associated with safety related equipment. There are alternate means in the Control Room to determine equipment status although they are less efficient.

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HEDs TO BE ADDRESSED AF~rR RESTART HED NO.

9.2-83 ICS Track Mode Indication There is no display in the Control Room to indicate when the Integrated Control System is in Track Mode. The Integrated Control System Track Mode is an automatic control function which is initiated when automatic control of either the reactor feedwater/ steam generator or turbine generator can no longer be maintained. The inability to maintain automatic control may be the result of a wide variety of control or system malfunctions or limitations which places a restriction on the power produc-tion capabilities of either the reactor or steam generator /feedwater or turbine generator systems. The Integrated Control System then forces the entire plant to " track" the power production capacity of the limiting system or subsystem. The Integrated Control System can, therefore, cause a reduction in power output in response to a control or system upset by automatically reducing reactor power, feedwater flow, or turbine generator output in just a few minutes to reach a new system equilibrium.

The lack of an indicator identifying the Track Mode of operation complicates the operator's response to the power reduction transient. Note that there are indicating lights for the unit load demand station (manual and automatic ICS operation), which would both be lit in the case of the ICS being in " Track" mode.

A corrective action for this HED has been proposed for implemen-tation af ter restart and will be considered as a part of the Annunciator Study. This HED is not associated with safety related equipment and is of low safety significance. The inability to quickly identify the Track Mode of operation can complicate the operator's response, but would only affect the end result of the transient in certain special circumstances where prompt operator action might prevent a possible reactor trip.

9.2-84 Denerator Level Control Valve Position Indication There is no display in the Control Room to indicate the actual valve position of the deaerator level control valve, which complicates the evaluation of secondary side transiento affect-ing deaerator level.

This HED was not addressed as a part of the SRTP. It is not associated with safety related equipment and is of low safety significance. It will be addressed as a part of the Display Study after restart.

9.8-7 Precision of Scales in Dicplays Meters on the Post Accident Monitoring Panel (PAM) and a few other displays do not provide the desired precision or accuracy.

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O HEDs TO BE ADDRESSED AFTER RESTART HED NO.

This HED will be resolved af ter startup. The portion of this HED related to the PAM panel indication is of medium safety significance and is similar to HED 5.1.29 on parallax problems with PAM panel indication. As described, plans are already being developed to significantly modify tit existing PAM panels to include meters with appropriate precis'on and accuracy. The same information in a more precise format is available in the Control Room although it is not centralized. The primary indication of concern in this HED is the display or lucere exist thermocoupie Lewperatures. These indications are also available in the Control Room on the Safety Parameter Display System terminals in a much more accurate format although the SPDS is not safety grade. These thermocouple readings can also be read outside the control Room, if necessary.

JRL/300 l

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