ML20204G118

Forwards Supplemental Response to Generic Ltr 82-28, Inadequate Core Cooling Instrumentation Sys & NUREG-0737, Item II.F.2.W/one Oversize Drawing.Aperture Card Is Available in PDR

ML20204G118
Person / Time
Site:	Beaver Valley
Issue date:	04/21/1983
From:	Carey J DUQUESNE LIGHT CO.
To:	Varga S Office of Nuclear Reactor Regulation
Shared Package
ML20204G121	List: ML20204G118 ML20263T495
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.2, TASK-TM GL-82-28, TAC-45114, NUDOCS 8305020359
Download: ML20204G118 (22)

Text

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?Af Telephone (412) 393-6000 Nuclear Division P.O. Box 4 Shippingport PA 15077-0004 April 21, 1983 Director of Nuclear Reactor Regulation United States Nuclear Regulatory Commission l Attn: Mr. Steven A. Varga, Chief Operating Reactors Branch No.1 Division of Licensing Washington, DC 20555

Reference:

Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Generic Letter No. 82-28; Supplemental Response on ICC Instrumentation System Centlemen:

This submittai is being provided to complete our response to Generic Letter 82-28, Inadequate Core Cooling Instrumentation System, dated December 10, 1982. Included is an Attachment which provides informa-tion relative to items 4 and 5, II.F.2 Attachme^t 1 and Appendix B (of UUREG-0737) as included in Generic Letter 82-28.

Since our initial response to NUREC-0737, dated December 31, 1980, we have been reviewing our existing core exit thermocouples (CETC's) agains t the design and qualification criteria contained in NUREG-0737.

The purpose for this review was to determine if the CETCs could be up-graded to NUREG-0737 criteria, what would be involved in the upgrade and the benefit gained through the upgrade with respect to providing the plant operators an absolute means by which they could identify the approach to inadequate core cooling. We have concluded that the up-grading of CETCs will not result in sufficient improvements to plant safety to justify the costs associated with pursuing a goal for qualifica-tion which has not been proven to be attainable.

Beaver Valley, Unit 1, uses the Westinghouse supplied CETC system.

This system includes chromel-alumel thermocouples in stainless steel sheaths which extend from the core exit region to penetrations in the reactor vessel head. At these penetrations, thermocouple extension wires connect with the CETCs and go to a Reference Junction Box. The reference junctions permit use of conventional copper wiring from the junction boxes through the containment penetrations to the thermocouple readout devices. Refer to Figure 5 for a simplified sketch of this system. The i original installation requirements for these CETCs did not include environ-mental or seismic qualification or the separation requirements as specified for lE systems. The results of our review has concluded that this system 0305020359 830421

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,, Beaver Valley Power Station, Unit No.1 Docket No. 50-334, License No. DPR-66 Generic Letter No. 82-28; Supplemental Response j on ICC Instrumentation System '

Page 2 l

will not be capable of providing the operator absolute information regarding core exit temperatures and may still not meet the complete design criteria of NUREG-0737 following extensive ef forts to upgrade this system. The most useful information the operator could obtain f rom this system is trending information and it has been determined that the CETCs did provide trending information at TMI.

Our containment design and equipment layout makes the task of attempting to upgrade this system extremely dif ficult. Extensive cable and conduit routing and cabinet replacement or relocation would be required to satisfy all lE and separation criteria. Even with these modifications, separation criteria cannot be met in the area of the reactor vessel head. We estimate that costs in excess of 4 million dollars could be expected if we were to pursue this upgrade and the results would j still produce an indication that the operator could not take as absolute, i From a technical perspective, the small EMF produced by the CETCs can still be significantly influenced by changing containment temperatures affecting the isothermal assembly in the reference junction box or from electromag-netic interference. While the Reference Junction Boxes sre temperature compensated, accuracy of the CETC would deviate during LOCA induced envir-onmental conditions within containment. Additionally, when considering accuracy over an extended range, the non-linearities of the transducers, wiring, pre-processing electronics stability and scale compression all contribute to degrade accuracy. We have concluded that even with a system for which an upgrade has been attempted, any signal interference will result in degrading loop accuracy and resolution, and that the best we can expect to obtain is trending information.

From an operating perspective, the absence of environmental quali-fications on the incore thermocouples can be evaluated appropriately by determining what potential non-conservative actions could be taken by the operator if anomalous indications were being given by these devices during a safeguards system actuation. The BVPS Unit I design does not provide for remote throttling of high head safety injection flow during the injection phase below the capacity of a single 100% high bead charging pump.

In order to satisfy the procedural requirements for termination of safety injection, the following conditions must be satisified:

- normal indications for the containment sump level and sump temp-e ra tu re normal pressure and radiation levels in containment

- normal radiation levels in the steam generator blowdown and air ejector effluent reactor coolant pressure greater than 2000 psig and increasing

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.. Bezver Valley Power Station, Unit No.1 Docket No. 50-334, License No. DPR-66

' Generic Letter No. 82-28; Supplemental Response on ICC Instrumentation System Page 3 pressurizer level greater than 22%

- 50*F subcooling l

350 gpm of auxiliary feed flow into the steam generators, or narrow range level in nt least one steam generator 2 20%

Noting that the only time during the termination that the thermo- I couples could be used is in determining the subcooling margin. If all other termination criteria are met, then the wide range hot leg temp- ,

erature indications would provide the equivalent information and also indicate the onset of an inadequate core cooling (ICC) condition as they did at TMI at two hours into the event.

If the readings from the thermocouples were inconsistent due to any hypothetical accident induced fault, then it would not be possible to meet all safety injection termination criteria and the operator would be forced to maintain full safety injection flow to the coolant system.

As detailed in the Kemeny Report, (Reference 2) "if the safety injection flow was not throttled, a stable condition would have been achieved with no damage to the core", therefore, we have concluded that there is no substantial basis to justify upgrading the incore thermocouples at BVPS Unit 1. The fact that a particular instrument responds to an event should not be the sole consideration for requiring qualification of the device for the full LOCA envelope of operating conditions. As is the case of

, the TMI incore thermocouples, (Reference 1), we would expect that the majority of our 51 thermocouples would survive a similar event. It is i also evident (Reference 1) that the hot leg temperature indication properly responded to the onset of the ICC condition and provided equivalent infor-mation when the indicators went off scale at 700*F. Licensed operators at Beaver Valley have been trained on the expected response of these and other instruments during requalification training, i Since termination of safety injection is not keyed strictly to performance of the thermocouples and core damage would be precluded by maintaining full high head injection in the absence of meeting the subcooling criteria, we do not believe that upgrading the thermocouples to meet the full regulatory requirements of NUREG-0737 and Regulatory Guide 1.97 is justified.

l If you have any questions, please contact myself or members of my staff.

Very truly yours, J

! J. J. Carey Vice President, Nuclear

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Beaver Valley Power Station, Unit No.1 Docket No. 50-334, License No. DPR-66 Generic Letter No. 82-28; Suppleuental Response on ICC Instrumentation System Page 4

References:

(1) NSAC 80-1, March 1980, Analysis of Three Mile Island Unit 2 Accident (2) Report of the President's Commission on the Accident at Three Mile Island, October 1979 Attachment cc: Mr. W. M. Troskoski, Resident Inspector U. S. Nuclear Regulatory Commission Beaver Valley Power Station Shippingport, PA 15077 U. S. Nuclear Regulatory Commission c/o Document Management Branch Washington, DC 20555

e COMMONWEALTH OF PENNSYLVANIA)

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COUNT ( OF BEAVER )

0 this d/ day of 14 6 ,

/ f M , before me, L /> 7//. J/fie/tt , a Notary /Public in and for said Commonwealth and County, personally appeared J. J. Carey, who being duly sworn, deposed, and said that (1) he is Vice President of Duquesne Light, (2) he is duly authorized to execute and file the foregoing Submittal on behalf of said Company, and (3) tre statements set forth in the Submittal are true and correct to the best of his knowledge, information and belief.

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n' ATTACHMENT Supplemental Response to Generic Letter 82-28 Inadequate Core Cooling Instrumentation System dated December 10, 1982 Checklist for Plant Specific Review of Inadequate Core Cooling (ICC) Instrumentat1on System For: Beaver Valley Power Station, Unit No. 1 Docket No. 50334 Operated by: Duquesne Light Company Reference Devia tions Schedule

4. Prov$de a table or description covering the evaluation of con-formance with NUREG-0737: II.F.2, Attachment 1, and Appendix B (to be reviewed on a plant spec-ific basis)

• See Below Yes Complete

Response

This evaluation of conformance is provided in the attached TABLES.

5. Describe computer, software and display functions assoc 1-ated with ICC monitoring in the plant See Below No Complete

Response

The following is a description of the plant computer and subcooling margin monitor microcomputer which serve as components of the ICC Instrumentation System.

DESCRIPTION OF MAIN COMPUTER The Beaver Valley Power Station Main computer is used for the moni-toring of primary and secondary plant parameters. The computer obtains data by scanning analog and digital sensors. It then logs data, performs data analog and digital trending, performs alarm limit supervision and annunciates off-normal conditions. Also included are reactor control and protection system monitoring, secondary plant performance calculations, and core physics monitoring. The power supply for this system is provided via the emergency busses.

.. Attachment Generic Letter 82-28 Supplemental Response Page 2

SUMMARY

DESCRIPTION  !

The basic equipment, or hardware, of the computer system includes a central processing unit (CPU), an input / output unit, a rapid access disc, an operator's console with output typewriters (OPCON), and a programmer's console.

The OPCON provides the communication link between the station operating personnel and the computer. It is through this console that data may be entered or requested, programs initiated and of f-normal situations annunciated. The console is the only piece of the computer system that is located in the control room. Under normal operating conditions, the OPCON is the only part of the computer with which the station operator will be concerned.

The remainder of the computer system is located in the computer room adjacent to the main control room. The programmer's console consists of a paper tape punch, paper tape reader, and an IBM Model 735 input / output typewriter.

The central processing unit is housed in two cabinets and is the primary controlling element for most system functions. The CPU addresses core memory, acquires and stores information, sequences and controls instruction execution, and controls the exchange of information between core menory and other parts of the system.

Input / output cabinets are also located in the computer room. Each cabi-net houses the various panels needed for communication between the CPU and the monitored processes. Included in the cabinets are analog to digital converters, reference junction boxes, a demultiplexer, and term-inal strips for incoming process signals.

Two (2) six-digit visual display units are provided on the operator's panel. Any analog input or addressable value may be displayed b1 numer-ical engineering units on this display. One such unit displays the input identification, the other displays the value. The program updates the display windows every four seconds.

INCORE T/C FMP l

l This function permits the operator to obtain any of 53 possible incore thermocouple maps on any of five possible output device combinations.

The 53 incore T/C maps, with their corresponding VALUE 1, (Map Code) and VALUE 3 (Form Code) pushbuttons entries, are:

MAP VALUE 1 VALUE 3 Long-form 1-minute-old map 0 0 Short-form 1-minute-old map 0 1 24 long-form hourly maps 1-24 0 i

L

'. Attachment Cencric Letter 82-28 Supplemental Response Page 3 1

s 24 short-form hourly maps 1-24 1 Long-form current (most recent) map 25 0

. Short-form current (most recent) map 25 1

History map 26 1

'The five device combinations, with their corresponding VALUE 2, (Device code), are:

Output Device VALUE 2 Trend Typewriter 10 Progconsole Typewriter 20 1,

Progconsole Tape Punch 30

! Trend Typewriter and Tape Punch 13 f

Progconsole Typewriter and Tape Punch 23 DESCRIPTION OF SUBCOOLING MARGIN MONITOR Core Cooling Monitor [SCM-RC-100]

i The primary function of the core cooling monitor is to provide the l operator with indication of the margin to saturation of the primary l coolant in the reactor core.

The monitor can also be used to verify that natural circulation is taking place as well as a digital indication of pressure, temperature, and saturation temperature for existing pressure, i

The core cooling monitor is an 8-bit 8080A based microcomputer dedicated to monitor primary plant pressure and temperature. It is programmed to provide various functions to aid the operator in determining the condition of the core.

The core cooling monitor provides the margin to saturation on an analog remote meter located above the core cooling monitor as well as on a digital display on the monitor itself. The monitor is located i on the vertical board, Section B.

Attachmeat Generic Letter 82-28 l Supplemental Response i l

Page 4 In addition to margin to saturation, the monitor provides caution and alarm status lights and annunciator contacts to warn the operator of an unacceptable margin to saturation or of a monitor malfunction. The monitor also provides the operator with the saturation temperature for the lowest primary plant pressure, core delta-T information for determining natural circulation flow, and access to individual pressure and temperature read-out's for each of the inputs.

The monitor receives its inputs from the same inputs for plant pressure and temperature that the P-250 computer receives. Eight in-core thermocouples, loop A and B wide range RTD's for Th and Tc, loop C wide range pressure, and pressurizer pressure are fed into this monitor. The monitor uses the highest temperature and the lowest pressure to determine the margin to saturation and to provide the ala rms . A front panel indicating light shows which pressure input is being used. The remote meter has a selector switch to allow the operator to display the margin to saturation on the analog meter as determined by the RTD's, or the thermocouples. As a back-up to this monitor, the operator has curves available which depict the margin to saturation and corresponding saturation curve based on plant pressure and temperature.

A pre-programmed read-only-memory (ROM) contains the necessary prodramming and data to provide the functions generated by this monitor. Random access memory (RAM) stores temporary inputs to the monitor for use in its calculation. Pressure and temperature are converted to digital form in an on board analog to digital (A to D) convertor. Outputs to the remote meter are converted to analog form in the computer's digital analog convertor (D to A) .

The core cooling monitor is an Intel 8080A single board computer. It uses national PROM / RAM boards for programming and scratch-pad memory.

Data TRANSLATION in-out (I/0) boards are provided to convert the pressure and temperature inputs to digital form for the computer and to allow the computer to generate a remote analog meter with an on-board power supply.

The monitor receives 120 VAC input power from PNL-AC-E4, an emergency power supply.

It provides outputs to the margin to saturation meter located above the monitor, and to an annunciator panel for caution and alarm conditions.

9. Provide a schedule for additional subuittals required ** Complete

.. At tachment Generic Letter 82-28 Supplemental Response Page 5

• II.F.2 Attacheent 1 (for Core Exit Thermocouples)

In response to item 4 in the above checklist, the following materials should be included to show that the proposed system meets the design and qualification criteria for the core exit thermocouple system.

1. Provide diagram of core exit thermocouple locations or reference the generic description if appropriate.

Response

Refer to Figure 1 for a diagram of the core exit thermocouple loca-tions. This figure is an example of a core map indicating core exit t empe ra tu res .

2. Provide a description of the primary operator displays including:

a. A diagram of the display panel layout for the core map and description of how it is implemented, e.g. , hardware or CRT display.

b. Provide the range of the readouts

c. Describe the alarm system

d. Describe how the ICC instrumentation readouts are arranged with respect to each other.

Response 2a:

Refer to Figure 2 for a diagram of the primary panel diaplay for any selected core exit thermocouple temperature. A core map, Figure 1, may be printed on demand by the Operator inputing the correct address statement to the computer at the console. The backup display is a Honeywell Precision Temperature Indicator which

! permits selection of a single thermocouple to be indicated using nonlocking key switches on the front of the indicator. The switch must be manually held in positicn to monitor the desired thermocouple.

In addition to this system, the operator may display core exit temper-atures on the subcooling margin monitor. Displays are continuous on demand. Refer to Figure 3 for the location of the CETCs providing l inputs to the subcooling margin monitor.

l There are presently two systems being installed which will enhance the operator's ability to monitor core exit temperatures. A new data aquisition system, referred to as the Plant Variable Computer System (PVS) and the Safety Parameter Display System (SPDS) . Each of these provide the operator a CRT display of each CETC temperature.

The PVS is an alpha-numeric df splay and the SPDS display is similar to that shown in Figure 1. These systems are being installed to enhance our emergency response capability.

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.. Attachment Generic Letter 82-28 Supplemental Response Page 6 Response 2b:

plant computer 0-700*F subcooling margin monitor 0-1650*F plant variable computer system 0-1650*F SPDS 0-2500*F Response 2c: r the plant computer alarms at 700*F and is displayed on the

] computer printer.

4 Response 2d:

refer to Figure 4 - to locate instrument displays i

3. Describe the implementation of the backup display (s) (including the subcooling margin monitors), how the thermocouples are selected, how they are checked for operability, and the range of the display.

4

Response

The back-up method for the plant computer system for determining

, core exit temperature was discussed in response ::> item 1 in our original response to Generic Letter 82-28, dated March 25, 1983.

There does not exist a pre-established method of thermocouple selection at the Honeywell Precision Temperature Indicator panel.

Operability is determined when the nonlocking key switch is moved to display a thermocouple reading.

The back-up method for the subcooling margin monitor is by using

the RCS pressure and temperature indication and determining degrees subcooled. Curves of pressure vs. temperature have been prepared and inserted in our procedures which identify 50' subcooled, 20' subcooled and saturated conditions. Pressure is obtained from the RCS wide range pressure transmitters and temperature is obtained f rom the wide range RTD hot leg temperature or the core exit thermocouple indication.

4. Describe the use of the primary and backup displays. What training will the operators have in using the core exit thermocouple instru-l mentation? How will the operator know when to use the core exit thermocouples and when not to use them? Reference appropriate emergency operating guidelines where applicable.

Response

The core exit thermocouple primary and secondary displays are used daily by the operators. The most frequent use is when a core map is being run and a core exit temperature printout similar to Figure 1 is requested.

Attachment Generic Letter 82-28 Supplemental Response

? age 7 All operators have been trained not to rely on any one indicator when evaluating plant parameters. A precaution statement has been added to our procedures advising the operators to monitor redundant or related channels to check for consistency while performing pro-cedure steps. Our E0Ps direct the operator to determine degrees subcooling by monitoring the CETCs or the wide range RTDs.

Additional training to the operators will be based on the new E0Ps which are currently under development. These are symptom based procedures which will follow the Westinghouse Emergency Response Guidelines (ERGS).

5. Confina completion of control room design task analysis applicable to ICC instrumentation. Confirm that the core exit thermocouples meet the criteria of NUREG-0737, Attachment 1 and Appendix B, or identify and justify deviations.

Response

The Westinghouse ERGS were developed to provide instructions for the operators to follow under emergency conditions. These guide-lines have as their basis the transie.nt and accident analysis for which the plant was designed and the steps necessary to mitigate these accident conditions. The new E0Ps will be validated as to their effectiveness in accordance with our response to Generic Letter 82-33 where a schedule has been presented for the completion of symptom based EOPs and a control room design review. An evalua-tion of the CETCs is included in the TABLES attached to this sub-mittal.

6. Describe what parts of the systems are powered from the lE power sources used, and how isolation from non-lE equipment is provided.

Describe the power supply for the primary display. Clearly delineate in two categories which hardware is included up to the isola tion device and which is not.

Response

The CETC and primary display system is powered from the emergency bus with diesel back-up provided. Included with this submittal is drawing number 8700-RE-lZ which is a one line diagram identifying the power supply to the computer.

7. Confirm the environmental qualification of the core exit thermocouple instrumentation up to the isolation device.

Response

The core exit thermocouple instrumentation is not environmentally qualified. Refer to the TABLES included with this submittal which provide the evaluation of conformance of the CETCs to NUREG-0737, Attachment 1 and Appendix B.

.. Attachment Generic Letter 82-28 Supplemental Response Page 8 Appendix B (of NUREG-0737, II.F.2)

Confirm explicitly the conformance to the Appendix B items listed below for the ICC instrumentation, i.e., the SMM, the reactor coolant inventory tracking system, the core exit thermocouples and the display systems.

Response

Subcooling Margin Monitor: This instrument was installed following NRC guidance provided in NUREG-0578 and as such its design did not include a reference to Appendix B of NUREG-0737. We will be review-ing this instrument as part of our review of Regulatory Guide 1.97, Rev. 2 to be done in accordance with our schedule submitted in response to Generic Letter 82-33, dated April 15, 1983.

Core Exit Thermocouples: Refer to TABLE 2 for the evaluation of the CETC to Appendix B.

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TABLE 1 i

NUREG 0737 Item II.F.2 Attachment 1 Design and Qualification Criteria For PWR Incore Thermocouples item Criteria Confo rmance No.

1 Sufficient number of thermocouples for Yes. See Figure 1 each core quadrant 2a A spatially oriented core map available Yes. See Figure 1 and Note 1 on demand 2b Selective reading of core exit Yes. See Note 2 temperature, continuous on demand 2c Direct readout and hardcopy capability Yes. See Note 2 and response to Item 2b in the attached response to this Generic Letter for readout ranges.

2d Trend capability, temperature time Yes. From the unit on-line computer history available on demand See Note 2 2e Appropriate alarm capalility Yes. Alarms at 700*F 2f Operator - display device interface Yes. See Note 3 3 Backup displays Yes. See Note 4 4a Human factors analysis on use of To be done as part of the Detailed information during normal and Control Room Design Review for ab-abnormal plant conditions normal operations 4b Integration into E0P's Yes. Utilizing Westinghouse Owner's Group ERGS 4c Integration into operator training Completed under ICC Training 4d Other alarms and need for prioritization The WOG ERGS address the priorities for maintaining all critical safety functions 5 Conformance to Appendix B No. See Table 2 6 Display channels should be electrically No. See Note 5 independent , Class lE power, and physically separated

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TABLE 1 Item Criteria Conformance 7 The instrumentation should be No. See Note 5 environmentally qualified 8 99% availability No. See Note 6 9 QA No. See Table 2 NOTES:

Note 1: In addition to the core map in Figure 1, upon completion of the SPDS, a copy of the CRT display of a spatially oriented core map will be available on demand.

No te 2 : The primary display can provide a continuous indication of a CETC on demand. The core subcooling monitor can also provide a digital indica-tion of a CETC at the microprocessor located in the control room. (see Figure 4). Upon completion of the plant variable. computer system and the SPDS, the operator will have two additional display capabilities available to him to continuously monitor CETC. This is a direct readout of core exit temperature and a hardcopy of the display is available.

Additionally, the plant variable computer can feed chart recorders to trend selected parameterc, which include CETCs.

Note 3: Rapid access to temperature displays is possible at the plant computer console. (See Figure 2). This will also be a feature of the two additional computer systems being installed in the control room.

Note 4: The back-up display for the primary CETC display is the Honeywell Pre-cision Temperature Indicator which is capable of monitoring all CETCs.

The subcooling margin monitor microprocessor display is capable of displaying any one of eight specific CETCs up to 1650*F. Additional monitoring capability will exist upon completion of the two computer systems being installed as discussed above.

Note 5: In order for our CETC system to satisfy these criteria, this system l

would have to be upgraded. It is our position that the benefit for upgrading cannot be justified as previously stated.

Note 6: This was not a design requirement when the plant computer was designed and installed. Additional display information, through the use of the two ncw computer systems, will provide additional display capabilities which have been designed to provide a high degree of availability.

TABLE 2 EVALUATION CHECKLIST NUREG-0737 Item II.F.2 Appendix B Criteria Core Exit Thermocouples Item Criteria Conformance No.

1 Instrument Environmentally qualified in No. The CETC's are part of the accordance with RG 1.89 (NUREG 0588) Incore Instrumentation and are instrument grade. It is our posi-tion that upgrading the CETCs cannot be justified.

2 No single failure should result in loss No, however, a diverse channel is of indication provided by the coolant loop wide range RTD's.

3 Class lE power The main computer is the readout device and is powered from an in-verter with a battery backup.

4 Instrument channel available prior to Yes.

an accident 5 QA requirements No. The CETCs were installed as instrument grade and as such, the QA provisions of Appendix B did not apply.

6 Continuous indication On demand only. Use of the unit-on-line computer is the normal means for recording incore thermo-couple readings. A Honeywell Pre-cesion Temperature Indicator provides backup readout capability. The two additional systems currently being installed will provide additional capability.

7 Recording of instrument readout Yes. The ins trument readout is recorded in the on-line computer and thermocouple histories can be made. Additional capabilities are currently being installed as previously discussed.

8 Instruments specifically identified No. The core exit thermocouples for use under accident conditions are part of the incore instrumenta-tion and are also used during normal operation.

TABLE 2 Item Criteria Conformance No.

9 Isolation devices No. There are no isolation devices.

10 Means should be provided for checking Yes. These instruments are used operational availability periodically during normal operation 11- Servicing, testing and calibrating Yes. Westinghouse provided technical programs to maintain instruments manual and calibration procedure.

12 Means for removal from service in Yes. Administrative controls exist the design should facilitate admin- for removing equipment from service.

instrative control of access to the means for removal from service 13 Design should facilitate administrative Yes. Access to this en,uipment is control of access to set points and restricted, adjustments 14 Monitoring instrument design should Yes. By design, this system is very minimize conditions giving confusing simple and is not susceptable to indications conditions resulting in anomalous indications.

15 Design should facilitate recognition, No. The reference Junction Boxes are location, repair replacement, or ad- inside containment and may not be justment of malfunctioning components accessible.

16 Instrumentation inputs should be from Yes. The CETC's directly measure sensors measuring the variable core exit temperature 17 Instruments should be used for both Yes. The CETC may be used by the normal and accident monitoring operators, in conjunction with other instruments, at all times.

18 Periodic testing per R.G.1.118 No. This criteria was not an original design requirement for our CETC system.

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