ML20210G480

Proposed Tech Specs 3/4.3.2.1 Re Safety Features Actuation Sys Instrumentation & Associated Bases

ML20210G480
Person / Time
Site:	Davis Besse
Issue date:	07/26/1999
From:	CENTERIOR ENERGY
To:
Shared Package
ML20210G444	List: ML20210G439 ML20210G463 ML20210G480
References
NUDOCS 9908030107
Download: ML20210G480 (17)

Text

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LAR 97-0012 Page 9 INSTRUMENTATION 3/4.3.2 SAFETY SYSTEM INSTRUMENTATION SAFETY FEATURES ACTUATION SYSTEM INSTRUMENTATION LIMITING CONDITION FOR OPERATION 3.3.2.1 ne Safety Features Actuation Syswm (SFAS) functional units shown in Table 3.3-3 shall be OPERABLE with their trip setpoints set consistent with the values shown in the Trip Setpoint column of Table 3.3-4, with the exception ofinstnament Strings Functional Units d and e. Scauence Loric Channels Functional Units a and b. and Interlock Channels Functional Unit a which shall be set consistent with the Allowable Value column of Table 3.3-4.

APPLICABILITY: As shown in Table 3.3-3.

ACTION:

a. With a SFAS functional unit trip setpoint less conservative than the value shown in the Allowable Values column of Table 3.3-4, declare the functional unit inoperable and apply the applicable ACTION requirement of Table 33-3, until the functional unit is restored to OPERABLE status with the trip setpoint adjusted consistent with Table 3.3-4.

b. With a SFAS functional unit inoperable, take the action shown in Table 3.3-3.

SURVEILLANCE REQUIREMENTS 4.3.2.1.1 Each SFAS functional unit shall be demonstrated OPERABLE by the performance of the CHANNEL CHECK, CHANNEL CALIBRATION and CHANNEL FUNCTIONAL TEST during the MODES and at the frequencies shown in Table 4.3-2.

4.3.2.1.2 De logic for the bypasses shall be demonstrated OPERABLE during the at power CHANNEL FUNCTIONAL TEST of functional units affected by bypass operation. The total bypass function shall be demonstrated OPERABLE at least once per REFUELING INTERVAL during CHANNEL CALIBRATION testing of each functional unit affected by bypass operation.

4.3.2.1.3 He SAFETY FEATURES RESPONSE TIME' of each SFAS function shall be demonstrated to be within the limit at least once per REFUELING INTERVAL. Each test shall include at least one functional unit per function such that all functional units are tested at least once every N times the REFUELING INTERVAL where N is the total number of redundar,t functional units in a specific SFAS function as shown in the " Total No. of Units" Column of Table 3.3-3.

9908030107 990726 PDR ADOCK 05000346 P PDR-

• The response times (except for manual initiation) include diesel generator starting and sequence loading delays, when applicable. The response time limit (except for manual initiation) includes movement of valves and attainment of pump or blower discharge pressure.

DAVIS-BESSE, UNIT I 3/43-9 Amendment No. 218,225,

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LAR 97-0012 Page 12

. Tills PAGE PROVIDED

. FORINFORMATION ONLY (

T_ABLE 3.3-3 (Continued)

TABLE NOTATION l l

• Trip function.may be bypassed in this MODE with RCS pressure below 1800 psig. Bypass shall be automatically removed when RCS pressure exceeds 1800 psig.

• • ' Trip function may be bypassed in this MODE with RCS pressure below l 660 psig. Bypass shall be automatically removed when RCS pressure i exceeds 660 psig.

• • • DELETED (

• • • • DELETED

• • • • • All functional units may be bypassed for up to one minute when I starting each Reactor Coolant Pump or Circulating Water Pump. [

• • • • • • When either Decay Heat Isolation Valve is open.

1. The provisions of Specification 3.0.4 are not applicable.  !

ACTION STATEMENTS ACTI0tt 10 - With the number of OPERABLE functional units one less than the Total' Huniber of Units, STARTUP and/or POWER OPERATION may proceed provided both of the following conditions are satisfied:

a. The inoperable functional unit is placed in the tripped condition within one hour.

b. The Minimum Units OPERABLE requirement is met; however, one additional functional unit may be bypassed for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for surveillance testing per Specification 4.3.2.1.1.

ACTION 11 - With any component in the Output Logic inoperable, trip the associated components within one hour or be in at least HOT STAftDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

1 DAVIS-BESSE, UNIT 1 3/4 3-12 Amendment No. GS,37,52,14 h H 5,159,165,211,218,221

LAR 97-0012 Page 13 THIS PAGE PROVIDED

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FORINFORMAil0N ONLY TABLE 3.3-3 (Continued)

ACTION STATEMENTS ACTION 12 - With the number of OPERABLE Units one less than the Total Number of Units, restore the inoperable functional unit to OPERABLE .

status within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or be in at least il0T STANDBY within the l next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. I ACTION 13 - a. With less than the Hii;imum Units OPERABLE and indicated re. actor coolant pressure ;t 328 psig, both Decay Heat i Isolation Valves (DHll and DH12) shall be verified closed.

b.

With Less than the Minimum Units OPERABLE and indicated reactor coolant pressure < 328 psig operation may continue; however, the functional unit shall be OPERABLE prior to increasing indicated reactor coolant pressure above 328 psig. l ACTION 14 - With less than the Minimum Units OPEPABLE and indicated reactor coolant pressure < 328 psig, operation may continu ; however, the.

functional unit shall be OPERABLE prior to increasing indicated reactor coolant pressure above 328 psig, or the inoperable functional unit shall be placed in the tripped state.

ACTION 15 - a.

With the number of OPERABLE units one less than the Minimum Units Operable per Bus, place the inoperable unit in the l tripped condition within one hour. For functional unit 4.a ,

the sequencer shall be placed in the tripped condition by '

physical removal of the sequencer rodule. The inoperable functional unit may be bypassed for up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for surveillance testing per Specification 4.3.2.1.1.

b.

With the number of OPERABLE units two less than the Minimum Units Operable per Bus, declare inoperable the Emergency l Diesel Generator associated with the.. functional units not I meeting the required minimum units OPERABLE and take the l ACTION required of Specification 3.8.1.1.

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LAR 97-0012 Page 17 3/4.3 INSTRUMENTATION BASES 3/43.1 and 3/4.3.2 REACTOR PROTECTION SYSTEM AND SAFETY SYSTEM INSTRUMENTA'ITON _1

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De OPERABILITY of the RPS, SFAS and SFRCS instrumentation systems ensure that 1) the associated action and/or trip will be initiated when the parameter monitored by each channel or combination thereof exceeds its setpoint,2) the specified coincidence logic is main:ained,3) sufficient redundancy is maintained to permit a channel to be out of service for testing or maintenance, and 4) sufficient system functional capability is available for RPS, SFAS and SFRCS purposes from diverse parameters.

He OPERABILITY of these systems is reqAired to provide the overall reliability, redundance and diversity assumed available in the facility design for the protection and mitigation of accident and transient conditions. He integrated operation of each of these systems is consistent with the assumptions used in the accident analyses.

He surveillance requirements specified for these systems ensure that the overall system functional capability is maintained comparable to the original design standards. The periodic surveillance tests performed at the minimum frequencies are sufficient to demonstrate this capability. The response time limits for these instrumentation systems are located in the Updated Safety Analysis Report and are used to demonstrate OPERABILITY in accordance with each system's response time surveillance requirements.

For the RPS, SFAS Table 3.3-4 Functional Unit Instrument Strings'd and e. Seauence Ienic Channels a and b and Interlock Channel a, and SFRCS Table 33-12 Functional Unit 2:

Only the Allowable Value is specified for each Function. Nominal trip setpoints are specified in the setpoint analysis. The nominal trip setpoints are selected to ensure the setpoints measured by CHANNEL FUNCTIONAL TESTS do not exceed the Allowable Value if the bistable is performing as required. Operation with a trip setpoint less conservative than the nominal trip setpoint, but within its Allowable Value, is acceptable provided that operation and testing are consistent with the assumptions of the specific setpoint calculations. Each Allowable Value specified is more conservative than the analytical limit assumed in the safety analysis to account for instrument uncertainties appropriate to the trip parameter. Rese uncertainties are defined in the specific setpoint analysis.

A CHANNEL FUNCTIONAL TEST is performed on each required channel to ensure that the eatire channel will perform the intended function. Setpoints must be found within the specified Allowable Values. Any setpoint adjustment shall be consistent with the assumptions of the current specific setpoint analysis.

A CHANNEL CALIBRATION is a complete check of the instrument channel, including the

sensor. The test verifies that the channel responds to the measured parameter within the i necessary range and accuracy, CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drift to ensure that the instrument channel remains operational between successive tests. CHANNEL CALIBRATION shall find that measurement errors and bistable setpoint errors are within the assumptions of the setpoint analysis. CHANNEL CALIBRATIONS must be performed consistent with the assumptions of the setpoint analysis.

He frequency isjustified by the assumption of an 18 or 24 month calibration interval in the determination of the magnitude of equipment drift in the setpoint analysis.

l l l DAVIS-BESSE, UNIT I B 3/4 3-1 Amendment No. 73,125,128,211,218,225,  !

(Next page is B 3/4 3-la) j

I LAR 97-0012 l TlilS PAGE PROVIDED 3/4.3 INSTRUMENTATION BASES " ' ' ' 'N w"

3/4.3.1 and 3/4.3.2 REACTOR PROTECTION SYSTEM AND SAFETY SYSTEM INSTRUMENTATION (Continued) l The measurement of response time at the specified frequencies provides assurance that the RPS, SFAS, and SFRCS action function associated with each channel is completed within the time limit assumed in the safety analyses. l Response time may be demonstrated by any series of sequential, overlapping or total channel test measurements provided that such tests demonstrate the total channel response time as defined. Sensor response time verification may be demonstrated by either 1) in place, onsite or offsite test measurements or 2) utilizing replacement sensors with certified response times.

The actuation logic for Functional Units 4.a., 4.b., and 4.c. of Table 3.3-3, Safety Features Actuation System Instrumentation, is designed to provide protection and actuation of a single train of safety features equipment, I essential bus or emergency diesel generator. Collectively, Functi.onal Units 4.a., 4.b., and 4.c. function to detect a degraded voltage condition on either of the two 4160 volt essential buses, shed connected loads, disconnect the affected bus (es) from the offsite power source and start the associated emergency diesel generator. In addition, if an SFAS actuation signal is present under these conditions, the sequencer channels for the two SFAS l channels which actuate the train of safety features equipment powered by the affected bus will automatically sequence these loads onto the bus to prevent overloading of the emergency diesel generator. Functional Unit 4.a. has a total of four units, one associated with each SFAS channel (i.e., two for each essential bus). Functional Units 4.b. and 4.c. each have a total of four units, (two associated with each essential bus); each unit consisting of two undervoltage N1ays and an auxiliary relay.

An SFRCS channel consists of 1) the sensin'g devics(s), 2) associated logic and output relays (including Isolation of Main Feedwater Non Essential Valves and Turbine Trip), and 3) power sources. l The SFRCS response time for the turbine stop valve closure is based on the combined response times of main steam line low pressure sensors, logic cabinet delay for main steam line low pressure signals and closure time of the turbine stop valves. This SFRCS response time ensures that the auxiliary feedwater to the unaffected steam generator will not be isolated due to a SFRCS low pressure trip during a main steam line break accident.

l Safety-grade anticipatory reactor trip is initiated by a turbine trip (above 45 percent of RATED THERMAL POWER) or trip of both main feedwater pump turbines. This anticipatory trip will operate in advance of the reactor coolant sy:, tem high pressure reactor trip to reduce the peak reactor coolant system pressure and thus reduce challenges to the pilot operated relief valve.

This anticipatory reactor trip system was installed to satisfy Item II.K.2.10 of NUREG-0737. The justification for the ARTS turbine trip arming level of 45% is given in BAW-1893, October, 1985.

DAVIS-BESSE, UNIT 1 B 3/4 3-la Amendment No. M rl45,+2Brl-35,-21h31b 225 L- U

i LAR 97-0012 l Attachment Page 1

- Summary of the 90*/. Undervoltane Relay Setnoint Analysis General The setpoint analysis was performed in accordance with ISA-RP67.04, Part II,

" Methodologies for the Determination of Setpoints for Nuclear Safety-Related Instrumentation," September 1994.

The basic fonnula for uncertainty calculation takes the form:

Z = i( A +2 B + C ) v2 g lpg + g , g 2 2 where A,B,C = random and independent terms. The terms are zero-centered, approximately normally distributed, and are indicated by a i sign.

1 F = abnormally distributed uncertainties and/or bias (unknown sign).

The term is used to represent limitt of error associated with uncertainties that are not normally distributed and do not have known direction. The magnitude of this term (absolute value) is i assumed to contribute to the total uncertainty in a worst-case direction and is also indicated by a i sign.

i L&M = biases with known sign.

Z = resultant uncertainty. The resultant uncertainty combines the random uncertainty with the positive and negative components of the non-random terms separately to give a final uncertainty. The positive and negative non-random terms are not algebraically combined before combination with the random component.

The establishment of setp 3ints and the relationships between trip setpoint, Allowable l Value, Analytical Limit. and Safety Limit are discussed in ISA-S67.04,"Setpoints for Nuclear Safety Related Instrumentation," September 1994.

l l Safety Limits are chosen to protect the integrity of phy sical barriers that guard against the uncontrolled release of radioactivity. These Safety Limits are provided in the Technical Specifications and safety analyses. Analytical Limits are established to ensure that the Safety Limits are not exceeded. Allowable Values are values that the trip setpoint might have when tested periodically, beyond which the instrument channel should be evaluated for operability. An "as-found" trip setpoint within the Allowable Values ensures that sufficient margin exists between this actual setpoint and the analytical limit to account for instrument uncertainties, such as design-basis accident temperature effects, that either are l

i

L LAR 97-0012 Attachment Page 2 not present or are not measured during periodic testing. This will ensure that the L analytical limit will not be exceeded if the Allowable Value is satisfied. The Allowable l Value also provides a means to identify unacceptable instrument performance that may

! require corrective action.

l l The Allowable Value determination is based on ISA-RP67.04, Part II, Section 7.3,

" Method 2". This method determines the Allowable Value by calculating the instrument channel uncertainty without including drift calibration uncertainties and uncertainties observed during normal operation. This result is then subtracted from the Analytical Limit to establish the Allowable Value.

l The trip setpoint is a predetermined value at which a bistable module changes state to indicate that the quantity under surveillance hr.s reached the selected value. The trip setpoint is established to ensure that an instrument channel trip occurs before the Analytical Limit is reached and to minimize spurious trips close to the normal operating ,

point of the process.

The trip setpoint is determined by adding or subtracting the instrument channel uncertainties to the Analytical Limit, dependent upon the conservative direction of the process variable with respect to the Analytical Limit, according to the following formula: '

TS = AL i(CU + margin) where TS = trip setpoint AL = analyticallimit CU_ = channel uncertainty 1

Margin = an amount chosen, if desired, by the user for conservatism of the trip setpoint.

For process variables that decrease toward the Analytical Limit, the instrument channel uncertainty and margin terms are added to the Analytical Limit. For process variables that increase toward the Analytical Limit, the margin terms are subtracted from the Analytical Limit.

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LAR 97-0012 Attachment :

Page 3 Voltane AnalyticalLimit The Analytical Limit, based on the minimum required Motor-Operated Valve starting voltage, is 3690 Volts, which includes a margin of 7.3 Volts to accommodate potential future design changes.

Allowable Value The Allowable Value was determined by calculating the instrument channel uncertainty without including drift calibration uncertainties and uncertainties observed during normal operation, and adding this result to the Analytical Limit.

The uncertainties were determined to be equal to i 11.20 Volts. An additional margin of 8.8 Volts was added to allow for changes in analysis or field conditions to be made without processing a License Amendment.

Allowable Value = 3690 Volts + 11.20 Volts + 8.8 Volts = 3710 Volts Trip Setpoint The trip setpoint was determined by adding or subtracting the instrument channel uncertainties to the Analytical Limit, dependent upon the conservative direction of the process variable with respect to the Analytical Limit, according to the formula described above.

The expected uncertainties stem from the following sources:

MATE Maintenance and Test Equipment D drift R repeatability, with constant temperature T . repeatability, with temperature variation PS power supply voltage variation PT Potential Transformer inaccuracy or non-linearity I

LAR 97-0012

(' Attachment l Page 4 I. ,

l CU = f( (M&TE) 2 + (R): + (D) 2 + (T) 2 + (PS) 2)ir2 + PT )

= i( (8.45) ' + (0.35) 2 +(22.8) 2 + (3.7) 2 + (0.35) 2 )ir2 + 3 ;,i

= 35.7 Volts I I

( TS 2 AL + (CU + margin) (> sign added because margin may be larger) 4 l

2 3690 + (35.7 + 18.3) (18.3 Volts margin chosen so that result will be exactly 90% of base voltage) l 2 3744 Volts (90% of 4160 Volts) l > Potential Transformer Voltage = 107.0 Volts (35:1 Potential Transformer ratio) i Summary ofResults Analytical Limit = 3690 Volts Allowable Value 2 3710 Volts l Trip Setpoint = 3759 Volts,107.4 Volts at the relays (includes additional i ' 15 Volts margin at 4160 Volt base, to reduce l calibration frequency)

Ilms AnalyticalLimit The lower Analytical Limit for these relays is ti.5 seconds, based on the High Pressure i Injection Pump Motors' start time at 70% of nominal voltage. For the upper Analytical Limit, analysis and testing support a degraded voltage relay time delay of 9 seconds.

l- Analytical Limit = 6.5 to 9 seconds

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l LAR 97-0012 Attachment Page5 Allowable Value l

The upper Allowable Value is determined by calculating the instrument channel uncertainty without including drift calibration uncertainties and uncertainties observed during normal operation. The result is then subtracted from the Analytical Limit to establish the Allowable Value.

The uncertainties were determined to be equal to i 0.175 seconds. An additional margin of 0.125 seconds was added to allow for changes in design inputs to be made without processing a License Amendment.

l Allowable Value (upper) = 9.0 - 0.3 seconds = 8.7 seconds l

The lower Allowable Value was established by adding 0.3 seconds to the lower

! Analytical Limit to account for uncertainty and margin.

Allowable Value (lower) = 6.5 + 0.3 seconds = 6.8 seconds Trip Setpoint The trip setpoint was determined by adding or subtracting the instrument channel uncertainties to the Analytical Limit, dependent upon the conservative direction of the l process variable with respect to the Analytical Limit, acw ' mg to the formula I

described above.

l The expected uncertainties stem from the following sources:

M&TE Maintenance and Test Equipment D drift R repeatability, with constant temperature T repeatability, with temperature variation PS power supply voltage variation Time Dial inaccuracy of time dial setting on the relay CU= i( (M&TE) 2 + (R) 2 + (D) 2 + (T) 2 + (pg) 2 + (Time Dial) 2)ii2

=

+( (0.01) 2 + (0) 2 + (0.082)2 + (0.009) ' + (0) 2 + (0.174) 2 )i/2

= i0.2 L

F i LAR 97-0012 Attachment Page 6 TS = AL(upper)- (CU + margin)

=

9.0 - (0.2 + 0.8)

= 8.0 seconds TS = AL(lower) + (CU + margin)

=

6.5 + (0.2 + 1.3)

= 8.0 seconds l

A trip setpoint of 8.0 seconds provides a minimum margin of 0.8 seconds to the upper Analytical Limit. A higher margin,1.3 seconds,is provided to the lower Analytical Limit, due to the higher probability of challenging this limit.

4 Summary ofResults AnalyticalLimit(lower) 2 6.5 seconds AnalyticalLimit(upper) 5 9.0 seconds Allowable Value (upper) 5 8.7 seconds l Allowable Value (lower) 2 6.8 seconds l Trip Setpoint = 8.0 seconds l

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Docket Numbcr 50-346 License Nurnber NPF-3 Serial Number 2583 Enclosure 2 COMMITMENT LIST THE FOLLOWING LIST IDENTIFIES THOSE ACTIONS COMMITTED TO BY i DAVIS-BESSE NUCLEAR POWER STATION IN THIS DOCUMENT. ANY OTHER ACTIONS DISCUSSED IN THE SUBMITTAI, REPRESENT INTENDED OR PLANNED ACTIONS BY DAVIS-BESSE. THEY ARE DESCRIBED ONLY AS INFORMATION AND ARE NOT REGULATORY COMMITMENTS. PLEASE NOTIFY THE MANAGER- REGULATORY AFFAIRS (419-321-8466) AT DAVIS-BESSE OF ANY QUESTIONS REGARDING THIS DOCUMENT OR ANY ASSOCIATED REGULATORY COMMITMENTS.

COMMITMENTS DUE DATE List the SFAS Instrumentation Functional Unit No later than implementation Sequence Logic Channels "a"," Essential Bus of the requested License Feeder Breaker Trip (90%)", and "b", " Diesel Amendment.

Generator Start, Load Shed on Essential Bus (59%)" trip setpoints in the USAR (reference:

LAR 97-0012, pages 2 and 5).

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