ML17215A270

Safety Parameter Display Sys Parameter Selection Evaluation & Implementation Plan.

ML17215A270
Person / Time
Site:	Saint Lucie
Issue date:	03/01/1984
From:	FLORIDA POWER & LIGHT CO.
To:
Shared Package
ML17215A269	List: ML17215A268 ML17215A270
References
RTR-NUREG-0737, RTR-NUREG-737 GL-82-33, PROC-840301, NUDOCS 8403060116
Download: ML17215A270 (13)

Text

SAFETY PARAMETER DISPLAY SYSTEM PARAMETER SELECTION EVALUATION AND IMPLEMENTATIONPLAN

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h SPDS Page 2 of 6 I. D ESC RIPTI 0 N The purpose of the Safety Parameter Display System (SPDS) is to assist control room personnel in evaluating the safety status of the plant.'he SPDS at St. Lucie provides a continuous display of a wide variety of plant parameters on a 19" C RT centrally located in the control room.

Inputs to the St. Lucie SPDS are obtained via existing plant instrumentation, processed through a central computer, and then displayed on C RTs. There are three primary displays that may be shown on the CRTs, one for each major mode of operation - normal, heatup/cooldown, and shutdown cooling modes.

The necessary plant parameters are displayed in each 'mode to allow the control room operator to adequately assess plant safety status for a variety of normal and abnormal plant operating conditions. Supple mental para meters and trending information can also be displayed. A listing of chosen parameters for the primary displays supplied is in Table 1.

II. BASIS FOR PARANETER SELECTION N R C Generic Letter 82-33 entitled "Supple ment 1 to N U R E G-0737 Require m ents for E m ergency Response C apability" requires that, as a minimum, the SP 0 S should provide information to plant operators about:

i) Reactivity Control

-) Reactor core cooling and heat removal from the primary system iii) Reactor coolant syste m integrity iv) Radioactivity control v) Containment Integrity Additional guidance used to select SP DS parameters was obtained from work performed by a utility owners group, Regulatory Guide 1.97, and operating experience. The basis for the parameters selected to meet the requirements of each of the five areas identified in Generic Letter 82-33 is as follows:

Reactivit Control The purpose of monitoring a reactivity controi para meter is to provide to the operator the status of flux conditions within the reactor core. In order. to assess the reactor core flux conditions it is necessary to monltot reactor power in all ranges and rate of change of power.

Therefore, the SPDS monitors the startup range, wide range logarithmic and power range nuclear instruments. This provides the means to monitor core. flux conditions throughout all ranges of reactor operation. Changes in flux conditions are monitored'on the SPDS by the startup rate indication.

In addition to these parameters, reactor trip status is also displayed to provide the operator additional information on reactivity control syste ms status.

The SPDS'monitors core power, startup rate, and reactor trip status.

Based on the above evaluation, these parameters are sufficient to provide the operator with indication of reactivitiy control for a range of plant conditions.

SP DS Page 3 of 6

2. Reactor Core Coolin and Heat Removal from the Primar S stem The objective in this area is to provide sufficient indication such that an operator can determine, if the reactor core is being adequately cooled and heat is being continuously removed from this system. To ensure adequate core cooling and heat removal, it is necessary to ensure there is flow through the core and that a heat sink is available to remove heat from the core. There are three separate cases that must meet these criteria: RCS integrity maintained, loss of RCS integrity, and shutdown cooling.

'I In the case where RCS integrity is maintained, flow through the core must first be established. Core exit temperatures and cold leg temperatures are monitored on SPDS to assure that there is a differential temperature across the core and heat is being removed.

Subcooling margin assures there is no void formation that might impede natural circulation through the core when there is no forced flow. The primary heat sink for this case would be the steam generators. Steam generator levels and pressures provide indication that the steam generators are available as primary heat sinks.

In the case where RCS integrity is not maintained (i.e., LOCA) the Safety Injection Actuation message on SPDS indicates that cooling water is going to the reactor coolant system. Core exit temperatures are monitored to assure that heat is being removed. The reactor vessel level monitor indicates the extent to which the core is covered with water.

Finally, for the special case of shutdown cooling, a separate display provides indication of shutdown cooling flow and temperatures. This, combined with core exit temperatures, is a positive indication of heat re m oval.

These monitored para m e ters - core exit te m p era ture, cold leg te mperatures, subcooled margin, stea m generator level, stea m generator pressure, reactor vessel level, shutdown cooling temperatures and flow and the safety injection actuation message -are sufficient for the operator to assess reactor core cooling for a range of plant conditions.

30 RCS Inte rit The objective of this area is to provide sufficient indication such that an operator 'can determine 'if all primary coolant system boundaries are intact, thus maintaining coolant inventory for core cooling. RCS integrity may be breached either in the form of a Loss Of Coolant Accident (LO CA) to containment or as a Steam Generator Tube Rupture (SG T R).

Pressurizer level, pressurizer pressure and reactor vessel level are used to provide the operator with indication of a properly maintained Reactor Coolant Syste m boundary.

SP DS Page 4 of 6 Additional indication of a failure of RCS integrity in the form of a LO CA can be determined by containment radiation or by the containment environment indication. The containment environment indication will alarm if any of its input parameters - containment te mperature, pressure or sump level - exceed set limits.

Indication of a failure of RCS integrity in the form of a Steam Generator Tube Rupture (SGTR) is provided by steam generator levels and pressures and by the secondary radiation indication. Rising steam generator level is one indication of an SGTR. The secondary radiation indication will alarm if either of its inputs, the steam generator blowdown radiation or air ejector radiation monitors, exceeds set limits. A SGTR could cause a secondary radiation alarm.

Additionally, charging and letdown system flows are also displayed.

Increased charging flow is the first sign of a small breach in RCS integrity.

These monitored para meters - pressurizer pressure, pressurizer level, reactor vessel level, containment environment, containment radiation, secondary radiation, stea m generator levels, stea m generator pressures, and charging and letdown flows - are sufficient to assess R CS integrity for a range of operating conditions.

R adioac tivit Control The objective of this area is to provide sufficient indication such that an operator can determine that no radioactive substances are being released to the environment in an uncontrolled manner.

Radioactive products can be released from the RCS into either the containment during a LOCA or into the secondary side during a steam generator tube rupture. Radioactivity control is, therefore, monitored in two ways, by the containment radiation indication and by the secondary radiation indication.

Containment radiation is supplied as a digital indication from 1 to 108 R/hr.,A high radiation signal also causes a containment isolation signal to be initiated to prevent uncontrolled release to the environm ent.

The secondary radiation indication will alarm if either of its monitored inputs - air ejector radiation or steam generator blowdown radiation-exceeds specified lim,its.

These indications - containment radiation and secondary radiation-provide the operator with indication of any potential uncontrolled

'radiation release.

SP DS Page 5 of 6 5 Containment Inte rit The objective of this area is to provide sufficient indication such that an operator can determine if a containment boundary is being maintained to control radioactive substances during and following a Loss of Coolant Accident (LOCA). To do this, challenges to the containment must be monitored.

Challenges to the containment are monitored via the containment environment indication. The contaiment environment indication is a derived parameter using containment temperature, pressure, and sump level as inputs. Should any of these parameters go out of established limits, an alarm will occur. This provides an indication that containment integrity is being challenged, and corrective actions should be taken by the operator. The message for a -Safety Injection Actuation Signal (SIAS) on the display will infer that a Containment Isolation Signal (C IS) has been initiated ( C IS occurs on SI AS).

These indications - containment environment and Safety Injection actuation - in conjunction with the RCS integrity parameters provide the essential information to assess containment integrity.

Based on the above information, the SP D S displays provide sufficient information for the control room operator to assess plant status during heatup-cooldown, normal operation, shutdown operation, and for a wide range of postulated plant accidents including Hain Steam Line Breaks (HSL6),

LO CA's, SG TR's, and Boron Dilution Events.

III. SAFETY ANALYSIS The Safety Parameter Display System is a nonwafety, non-seismic system (with the exception of the isolation system). It is a passive, monitoring and indication system only, and does not interact with the automatic initiation of any protection system.

All modifications to safety-class IE circuits where SPDS inputs are obtained satisfy the isolation and'qualification requirements of FSAR Section 7.1 and 7.5. Only Safety Class IE equipment is used and separation is provided by routing wires through totally enclosed metallic wireways dedicated to each safety division and terminating in the Class IE Termination Cabinets.

Furthermore, all interface between safety and non-safety signals are through

, . isolation devices fully, qualified and installed to IEEE-323-1974 and IEEE-344-1975 standards.

Finally, implementation of the SPDS will require no changes to the plant's Technical Spec ifications.

Based on the above information, it has been determined that installation and operation of the SPDS does not constitute an unreviewed safety question in accordance with 10 C F R50.59.

SP DS Page 6 of 6 I V. IH PL E H E N T A TI 0 N In FPL letter L-83-236, dated April 15, 1983, FPL committed to have the Safety Parameter Display System (SPDS) fully operable, including training of operators, by the Fall 1984 outage at St. Lucie Unit 1. Due to the extended outage at St. Lucie to remove the Thermal Shield, the next outage at Unit 1 1

is not planned until Fall 1985 (cycle 7). Because the SPDS installation can only be completed during a plant outage, final completion of the SPDS will be delayed until Fall 1985.

Therefore, FPL will have the SPDS fully operable, including training of operators, prior to startup following the Fall 1985 outage at St. Lucie Unit 1.

ST. LUCIE PLANT UNIT NO. 1 NUREG 0696 -'UNCTIONAL CRITERIA FOR EMERGENCY RESPONSE FACILITIES SAFETY PARAMETER DISPLAY SYSTEM (SPDS)

PARAMETER SELECTION TABLE 1 Page 1 KEY PARAMETERS REMARKS PLANT DESCRIPTION RANGE TYPE LOCATION OF PARA- DISPLAY TYPE e.g. NUMBER OF FUNCTION METER ON DISPLAY TARGET, BAR GRAPH INSTRUHENTS USED CPS Source Range Power 10 1 to 104 Direct Below Ti t le Digital Value 4 Level (Startup) CPS Average Percent Wide Range Power 1x10 8 amps Direct Below Title Digital Value 4 (Logrithmic) to 1504 Average REACTIVITY Percent Power 0 to 1254 Direct Below Title Digital Value 4 CONTROL (Linear) Average Startup Rate -1 to 7 dpm Direct Message Area Digital Value 4 Average Line 6 Reactor Trip Signal Ca l cu lated Message Area "'Message Line 7 Cold Leg Temperature 212o to 705oF Direct Top Row Right Bar Graph 6 Wide Range WR)

Average Digital Value 4 Narrow Range (NR Core Ex i t Tempera ture 32 to 2300oF Direct Bottom Row Digital Value 45 Thermocouples Average Right (TC's)

Feedwater Signal AFB Isolation This is a derived para-meter using AFAS ASB, Message Line 9 Area Message 6 Digital Contact Inputs

~

HSIS ASB, and SIAS ASB Main Steam Isolation Direct Hessage Area Message Signal (MSIS) ASB Line 8 REACTOR CORE 4 WR Co ld Leg COOLING AND 4 WR Hot Leg HEAT REMOVAL RCS Average Temperature A derived parameter Message Area Dig i ta I Va lue 4 NR Co I d Leg FROM THE from Hot 6 Cold Leg Temp. Line 5 4 NR Hot Leg PRIMARY SYSTEM

ST. LUCIE PLANT UNIT NO. 1

'UREG 0696 - FUNCTIONAL CRITERIA FOR EMERGENCY RESPONSE FACILITIES SAFETY PARAMETER DISPLAY SYSTEM (SPDS)

PARAMETER SELECTION TABLE 1 Page 2 KEY PARAMETERS REMARKS PLANT DESCRIPTION RANGE TYPE LOCATION OF PARA- DISPLAY TYPE e.g. NUMBER OF FUNCTION 'HETER ON DISPLAY TARGET, BAR GRAPH INSTRUMENTS USED Reactor Vessel Level 0 to 1004 Lowest Bottom Row Target 1 for Channel A Center 1 for Channel B Shutdown Cooling 0 to 8000 Direct Center Bar Graph S (SDC) Flow gpm Section Dig i ta l Va lue SDC from. RCS (Temp.) 0 to 400oF Direct Center/Left Bar Graph 6 REACTOR CORE Section Dig i ta 1 Va 1ue COOLING AND HEAT REMOVAL SDC to RCS (Temp.) 0 to 400oF Direct Center/Left Bar Graph 6 FROM THE Section Digital Value PRIMARY SYSTEM Safety Injection Direct Message Area Message 2 Digital Actuation Signal (SIAS) Line 10 Contacts Steam Generator (S/G) 0 to 1004 Average Center Section Bar Graph 6 4 NR S/G A Leve Is A 6 B Digital Value 4 NR S/G B S/G Pressure A 6 B 0 to 1200 Average Center Section Bar Graph 8 3S/G A Digital Value 3 S/G B Subcooling 700 to -2100oF Lowest Bottom Row Target (subcooled to superheat) Right Charging Fl'ow 0 to 150 gpm Direct Middle Row/Left Bar Graph 6 Digital Value RCS INTEGRITY Containment A der i ved par arne te r Bottom Row Target Cont. Level 2 Environment using containment Cont. Press. 8 pressure, temperature, Cont. Temp. 1 level

ST. LUG I E PLANT UNIT NO. 1 NUREG 0696 - FUNCTIONAL CRITERIA FOR EMERGENCY RESPONSE FACILITIES SAFETY PARAMETER DISPLAY SYSTEM (SPDS)

PARAMETER SELECTION TABLE 1 Page 3 KEY PARAMETERS REMARKS PLANT DESCRIPTION RANGE TYPE LOCATION OF PARA- DISPLAY TYPE e.g. NUMBER OF FUNCTION METER ON DISPLAY TARGET, BAR GRAPH INSTRUMENTS USED Conta inment Radiation 10o to 108 Average Bottom Row Digital Value 2 Low Range' R/HR Wide Range Core Exit Temperature 32 to 2300oF Direct Bot tom Row Digital Value 45 TC's Average Right Letdown Flow 0 to 140 gpm Direct Middle Row/Left Bar Graph 6 Digital Value Pressurizer Level 0 to 1004 Average Top Row Center Bar Graph S Digital Value RCS Pressurizer Pressure 0 to 1600 psia Direct Top Row Bar Graph 6 INTEGRITY Digital Value RCS Average Temperature Derived from Hot 6 Message Area Digital Value 4 WR Co I d Leg Cold Leg Temps. Line 5 4 WR Hot Leg 4 NR Cold Leg 4 NR Hot Leg RCS Pressure - 0 to 3000 psia Calculated Top Row Bar Graph 6 4 Narrow Range Digital Value 2 Wide Range Reactor Vessel Level 0 to 1004 Lowest Bottom Row Digital Value 1 - Ch. A Center 1 - Ch. B Secondary Radiatio~ Derived from S/G Bottom Row Left Target 1 - Air Ejector Blowdown 6 Air 2 - S/G B lowdown Ejector Radiation S/G Level AGB 0 to 1004 Average Cente'r Section Bar Graph S 4 NR S/G A Digital Value 4 NR S/G B S/G Pressure 0 to 1200 psia Average Center Section Bar Graph 6 3 S/G A Digital Value 3 S/G B

ST. LUCIE PLANT UNIT NO- 1 NUREG 0696 FUNCTIONAL CRITERIA FOR EMERGENCY RESPONSE FACILITIES SAFETY PARAMETER DISPLAY SYSTEM (SPDS)

PARAMETER SELECTION TABLE 1 Page 4

- KEY PARAMETERS REHARKS PLANT DESCRIPTION RANGE TYPE LOCATION OF PARA- DISPLAY TYPE e.g. NUHBER OF FUNCTION HETER ON DISPLAY TARGET, BAR GRAPH INSTRUMENTS USED RAD IOACTI VTY Conta inment 'Radiat ion 100 to 108 Average Bottom Row Digital Value 2 Low Range R/HR Ca lcu lated 2 Wide Range CONTROL Secondary Radiation Derived from S/G Bottom Row Target Air Ejector 1 Blowdown 6 Air S/G Blowdown Ejector Radiation CONTAINMENT Containment Environment A derived parameter Bottom Row Target Cont. Level 2 using containment Cont. Press. 8 INTEGRITY temperature, pressure, Cont. Temp. 1 6 level

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