ML18030B296

Proposed Tech Specs,Incorporating Calibr Frequencies Requested by NRC 851206 Ltr & Adding Requirements for Scram Pilot Air Header Low Pressure Trip

ML18030B296
Person / Time
Site:	Browns Ferry
Issue date:	04/29/1986
From:	TENNESSEE VALLEY AUTHORITY
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NUDOCS 8605080157
Download: ML18030B296 (16)

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TABLF. 3.1.A REACTOR PROTECTION SYSTEM (SCRAM) lNSTRUMENTATION REQUIREMENT Min. No. of Operable Inst. Modes in Which Function Channels Must Be 0 erable Per Trip Shut- Startup/Hot System(1) (23) T~ri Function T~vi Level Setting dorm Refuel(7) Standb Run Action(1)

Main Steam Line Isola-tion Valve Closure <104 Valve Closure X(6) 1.A or 1.

Turbine Cont, Valve Fast Closure or >550 psig X(4) 1.A or 1.D Turbine Trip Turbine Stop Valve Closure <10%, Valve Closure X(4) 1.A or 1.D Turbine First Stage Pressure Permissive not >154 psig X(18) X(18) X(18) (19)

(PIS-1-81ASB, PIS-1-91ARB)

Main Steam Line High 3X Normal Full Power X(9) X(9) X(9) 1.A or 1.C Radiation (14) Background (20)

Low Scram Pilot Air Header Pressure >50 psig X(2) X(2) 1.A pDR 57 Sb0rjp9 ADOCK 050002b0 p

pDR i r

NOTES FOR TABLE 3.I.A I. Thoro shall bo two operable or tripped trip systems for oach function.

If tho minimum numbor of oporablo instrument channels por trip system cannot bo mot for ono trip system, trip tho inoporablo channols or entiro trip system within one hour, or, altornatively, take tho below listod action for that trip function. If the minimum numbor of oporablo instrument channols cannot bo met by oithor trip system, the appropriate action listed below (refer to right-hand column of Table) shall bo taken. An inoporablo channol nood not bo placed in tho tripped condition where this would causo the trip function to occur. In thoso casos, tho inoporablo channol shall be restored to oporable status within two hours, or take tho action listed below for that trip function.

A. Initiate insortion of operable rods and complete insortion of all operable rods within four hours. In rofueling mode, suspend all operations involving coro altorations and fully insert all operable control rods within ono hour.

B. Reduce powor lovel to IRH range and placo modo switch in tho Startup)Hot Standby position within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

C. Reduco turbine load and close main steam lino isolation valvos within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

D. Reduco power to loss than 3Ã of ratod.

2. Scram discharge volumo high bypass may bo used in shutdown or refuol to bypass scram discharge volumo scram and scram pilot air header low pressuro scram with control rod block for roactor protection system rosot.

3. DELETED.

4. Bypassed when turbino first stago prossuro is less than l54 psig.

5. IRHs aro bypassed when APRHs are onscalo and the reactor modo switch is in tho run position.

6. The dosign pormits closure of any two linos without a scram being initiatod.

7. Mhen the roactor is subcrltical and the roactor wator temperature is loss than 2I2 F. only the following trip functions nood to be oporablo:

A. Hodo switch In shutdown

8. Hanual scram C. High flux IRH D. Scram discharge volume high lovel E. APRH le scram F. Scram pilot air header low prossure

8. Not required to bo oporablo when primary containment Integrity is not roqulrod.

9. Not required if all main steamlinos aro isolated.

TABLE 4.1.A REACTOR PROTECTION SYSTEM (SCRAM) INSTRUMENTATION FUNCTIONAL TESTS MINIHUM FUNCTIONAL TEST FREQUENCIES FOR SAFETY INSTR. AND CONTROL CIRCUITS

~Garou (2) Functional Test Minimum Fre uenc (3 Hain Steam Line Isolation Valve Closure Trip Channel and Alarm Once/3 Months (8)

Turbine Control Valve Fast Closure or Turbine Trip Trip Channel and Alarm Once/Honth (1)

Turbine First Stage Pressure Permissive Trip Channel and Alarm (7) Every 3 Months.

(PIS-1-81 AQ3, PIS-1-91 ASB)

Turbine Stop Valve Closure Trip Channel and Alarm Once/Month (1)

Low Scram Pilot Air Trip Channel and Alarm Once/6 Months Header Pressure PS 85 35 Al ~ A2~ Bl ~ & B2

TABLE 4.1.B REACTOR PROTECTION SYSTEM (SCRAM) INSTRUMENT CALIBRATION MINIMUM CALIBRATION FREQUENCIES FOR REACTOR PROTECTION INSTRUMENT CHANNELS Instrument Channel Garou (1) Calibration Minimum Fre uenc (2)

IRM High Flux Comparison to APRM on Controlled Note (4)

Startups (6)

APRM High Flux Output Signal Heat Balance Once every 7 days Flow Bias Signal Calibrate Flow Bias Signal (7) Once/operating cycle LPRM Signal TIP System Traverse (8) Every 1000 Effective Full Power Hours High Reactor Pressure Standard Pressure Source Once/18 Months (9)

(PIS-3-22AA, BB, C, D)

High Drywell Pressure Standard Pressure Source Once/18 Months (9)

(PIS-64-56 A-D)

Reactor Low Water Level Pressure Standard Once/18 Months (9)

(LIS-3-203 A-D)

High Water Level in Scram Discharge Volume Float Switches (LS-85-45 C-F) Calibrated Water Column Once/18 Months Electronic Level Switches (LS-85-45 A, B, G, H) Calibrated Water Column Once/18 Months (9)

Main Steam Line Isolation Valve Closure Note (5) Note (5)

Main Steam Line High Radiation Standard Current Source .(3) Every 3 Months Turbine First Stage Pressure Permissive (PIS-1-81 ARB, PIS-1-91 ASB) Standard Pressure Source Once/18 Months (9)

Turbine Stop Valve Closure Note (5) Note (5)

Turbine Cont. Valve Fast Closure A Standard Pressure Source Once/Operating Cycle on Turbine Trip Low Scram Pilot Air Standard Pressure Source Once/18 Months Header Pressure PS 85-35 Al, A2, Bl S B2

3.I BASES Tho reactor protoction system autceatically initiatos a roactor scram to:

I. Presorvo tho intogrity of tho fuel cladding.

2. Prosorvo tho intogrfty of the roactor coolant system.

Hinimize tho onorgy which must bo absorbod following a loss of coolant accident, and provents criticality.

This specification providos tho limiting conditions for oporation necossary to proservo the ability of tho system to tolorato singlo failuros and still perform its intondod function evon during por iods when instrument channols may be out of sorvico because of maintenance. Mhon necossary, ono channel may bo mado inoporable for brief intorvals to conduct roquired functional tosts and calibrations.

The reactor protection trip system is supplied, via a separato bus, by its own high inertia, ac motor-genorator sot. Altornate power is availablo to oither Reactor Protection System bus from an olectrical bus that can rocoive standby oloctrical powor. Tho RPS monitoring system providos an isolation betweon non-class IE powor supply and the class IE RPS bus. This will onsure that failure of a non-class IE roactor protection power supply will not cause advorso intoraction to tho class IE Reactor Protection System.

Tho reactor protoction system is mado up of two Independent trip systems (rofor to Section 7.2, FSAR) . Thoro aro usually four channels provided to monitor each critical paramotor, with two channols in oach trip system. The outputs of the channols in a trip system aro combinod in a logic such that either channol trip will trip that trip system. Tho simultaneous tripping of both trip systems will produce a roactor scram.

This system meets tho intent of IEEE - 279 for Nuclear Power Plant Protection Systems. Tho system has a roliability groator than that of a 2 out of 5 system and somewhat loss than that of a I out of 2 system.

Mith tho exception of the Avorage Powor Rango Honitor (APRH) channels, the Intormodiate Range Honitor (IRH) channels, tho Hain Stoam Isolation Valvo closuro and tho Turbino Stop Valvo closure, each trip system logic has one instrument channol. Mhon tho minimum condition for operation on the number of oporablo instrument channols por untripped protection trip system is met or if it H cannot bo met and tho offoctod protection trip system is placed in a tripped condition, tho offoctivenoss of tho protoction system is prosorvod; i.o., tho systom can tolorato a singlo failuro and still perform its intended function of scramnlng tho roactor. Throe APRH instrument channols aro provided for each protection trip system.

Each protection trip system has ono moro APRH than is necossary to meet tho minimum numbor roquirod por channol. This allows the bypassing of one APRH por protection trip system for maintonanco, tosting or calibration. Additional IRH channols havo also been provided to allow for bypassing of ono such channol. Tho basos for tho scram sotting for tho IRH, APRH, high reactor prossure, roactor low water lovel, I'ISIV closuro, turbine control volvo fast closuro and turbino stop valve closuro aro discussed In Specification 2.I and 2.2.

5.I BASES modos. In tho power rango tho APRM system provides roquirod protection.

Rof. Section 7.5.7 FSAR. Thus, tho IRM System is not roquirod in tho Run mode. The APRH's and tho IRH's provido adoquato coverago in tho startup and Intermediate rango.

Tho high roactor prossuro, high drywell prossuro, roactor low wator lovel, low scram pilot air hoador prossuro and scram discharge volume high lovol scrams aro required for Startup and Run modes of plant operation. Thoy are, thoroforo, required to bo oporational for thoso modes of roactor operation.

Tho requirement to have the scram functions as indicatod in Tablo 5.I.A oporablo in tho Rofuol mode Is to assuro that shifting to tho Rofuel modo during roacter power oporation does not diminish tho need for tho reactor protection system.

Because of tho APRH downscalo limit of > 5$ when in tho Run mode and high levol limit of < l5% when in tho Startup Hodo, tho transition botweon the Startup and Run Iiodos must bo mado with tho APRH instrumentation indicating botwoon 5g and l5%%u. of rated power or a control rod scram will occur. In addition, tho IRH system must be indicating below tho High Flux sotting (l20]I25 of scale) or a scram will occur when in tho Startup IIode. For normal oporating conditions, thoso limits provido assuranco of ovorlap between tho IRM system and APRH system so that thoro are no "gaps" in tho powor lovol indications (i.o., tho power levol is continuously monitored fran beginning of startup to full power and from full powor to shutdown) . Ifhon powor is boing roduced, If a transfer to tho Startup modo .is made and tho IRH's havo not boon fully insertod (a maloporational but not impossiblo condition) a control rod block imnodiatoly occurs so that reactivity insortion by control rod withdrawal cannot occur.

Tho low scram pilot air header prossuro trip porforms the smne function as the high wator levol in tho scram discharge instrument volume for fast fill ovents in which tho high lovol instrument rosponso time may be inadoquato. A fast fill ovont is postulated for cortain degraded control air ovents in which tho scram outlot valvos unsoat onough to allow 5 gpm por drive leakage into tho scram discharge volume but not enough to causo control rod insertion.

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TABLE 4.2.A SURVEILLANCE REQUIREMENTS FOR PRIMARY CONTAINHENT AND REACTOR BUILDING ISOLATION INSTRUMENTATION Function Functional Test Calibration Frequency Instrument Check Instrument Channel (1) (27) Once/18 Months (28) Once/day Reactor Low Water Level (LIS-3-203A-D)

Instrument Channel- Once/3 Months None Reactor High Pressure Instrument Channel (1) (27) Once/18 Months (28) Once/day Reactor Low Water Level (LIS-3-56A-D)

Instrument Channel (1) (27) Once/18 Months (28) N/A High Drywell Pressure (PIS-64-56A-D)

Instrument Channel (29) (5) Once/day High Radiation Main Steam Line Tunnel Instrument Channel- (29) (27) Once/18 Months (28) None Low Pressure Main Steam Line (PIS-1-72, 76, 82, 86)

Instrument Channel- (29) (27) Once/18 Months (28) Once/day High Flow Main Steam Line (PdIS-1-13A-D, 25A-D, 36A-D, 50A-D)

Instrument Channel (29) Once/operating cycle None Main Steam Line Tunnel High Temperature Instrument Channel (1)(14)(22) Once/3 Months Once/day(0)

Reactor Building Ventilation High Radiation Reactor Zone

TABLE 4.2.D SURVEILLANCE REQUIREMENTS FOR INSTRUMENTATION THAT INITIATE OR CONTROL THE CSCS Function Functional Test Calibration Instrument Check Instrument Channel (1) (27) Once/18 Months (28) Once/day Reactor Low Water Level (LIS-3-58A-D)

Instrument Channel (1) (27) Once/18 Months (28) Once/day Reactor Low Water Level (LIS-3-184 6 185)

Instrument Channel (1) (27) Once/18 Months (28) Once/day Reactor Low Water Level (LIS-3-52 & 62)

Instrument Channel (1) (27) Once/18 Months (28) None Reactor Low Water Level (LIS-3-56A-D)

Instrument Channel (1) (27) Once/18 Months (28) None Reactor High Pressure (PIS-3-204A-D)

Instrument Channel (1) (27) Once/18 Months (28) None Drywell High Pressure (PIS-64-58E-H)

Instrument Channel (1) (27) Once/18 Months (28) None Drywell High Pressure (PIS-64-58A-D)

Instrument Channel (1) (27) Once/18 Months (28) None Drywell High Pressure (PIS-64-57A-D)

Instrument Channel (1) (27) Once/18 Months (28) None Reactor Low Pressure (PIS-3-74ASB, PS-3-74ASB)

(PIS-68-95, PS-68-95)

(PIS-68-96, PS-68-96)

TABLE 4.2.C SURVEILLANCE REQUIREMENTS FOR INSTRUMENTATION THAT INITIATE ROD BLOCKS Function Functional Test Calibration (17) Instrument Check APRM Upscale (Flow Bias) (1) (13) Once/3 Months Once/day(8)

APRM Upscale (Startup Mode) (1) (13) Once/3 Months Once/day(8)

APRM Downscale (1) (13) Once/3 Months Once/day(8)

APRM Inoperative (1) (13) N/A Once/day(8)

RBM Upscale (Flow Bias) (1) (13) Once/6 Months Once/day(8~

RBM Downscale (1) (13) Once/6 Months Once/day(8W RBM Inoperative (1) (13) N/A Once/day(8)

IRM Upscale (1) (2) (13) Once/3 Months Once/day(8)

IRM Downscale (1) (2) (13) Once/3 Months Once/day(8)

IRM Detector not in (2) (Once/operating Once/operating cycle (12) N/A Startup Position cycle)

IRM Inoperative (1) (2) (13) N/A N/A SRM Upscale (1) (2) (13) Once/3 Months Once/day(8)

SRM Downscale (1) (2) (13) Once/3 Months Once/day(8)

SRM Detector not in (2) (Once/operating Once/operating cycle (12) N/A Startup Position cycle)

SRM Inoperative (1) (2) (13) N/A N/A ~

Flow Bias Comparator (1) (15) Once/operating cycle (20) N/A Flow Bias Upscale (1) (15) Once/3 Months N/A Rod Block Logic (16) N/A N/A RSCS Restraint (1) Once/3 Months N/A West Scram Discharge Once/quarter Once/18 Months N/A Tank Water Level High (LS-85-45L)

East Scram Discharge Once/quarter Once/18 Months N/A Tank Water Level High (LS-85-45M)

TABLE 4.2.F MINIMUM TEST AND CALIBRATION FREQUENCY FOR SURVEILLANCE INSTRUMENTATION Instrument Channel Calibration Fre uenc Instrument Check 17 Relief valve Tailpipe NA Once/month (24)

Thermocouple Temperature 18 Acoustic Monitor on Once/cycle (25) Once/month (26)

Relief Valve Tailpipe 19 High-Range Primary Containment Once/18 months (30) Once/month Radiation Monitors (RR-90-272CD) (RR-90-273CD) 20 Suppression Chamber Water Once/18 months Once/month Level-Wide Range (LI-64-159A) (XR-64-159) 21 Drywell Pressure-Wide Range Once/18 months Once/shift (PI-64-160A) (XR-64-159) 22 Suppression-Pool Bulk Temperature Once/18 months Once/shift (TI-64-161) (TR-64-161)

(TI-64-162) (TR-64-162) 23 High Range Gaseous Effluent Once/18 months Once/shift Radiation Monitor .

(RR-90-322A)

ENCLOSURE 2 Description and Justification Descri tion of Chan e Pages 34, 35, 38, 40 and 44 of Browns Ferry Nuclear Plant (BFN) unit 2 techincal specifications (TS) are revised to add requirements for trip level setting, functional test, and calibration for the trip input to the Reactor Protection System for "Low Scram Pilot Air Header Pressure." A paragraph is also added to the bases to describe this trip.

Page 42 of BFN unit 2 TS is revised to delete an obsolete reference to the loss of condenser vacuum scram in the bases of TS 3.1.

Pages 40, 85, 96, 102 and 105a of BFN unit 2 TS are revised to change "once/operating cycle" to "once/18 months" for the required calibration interval on items originally effected by TS 199. This change is in response to an NRC request and no additional justification is required. Additionally, this revision to the previously requested specification changes is conservative with Reason for Chan e respect to that previous change.

Pages 34, 35, 38, 40, 44 add the requirements for the Low Scram Pilot Air Header Pressure scram to technical specifications. These switches have been upgraded to class lE requirements as described in our letter from L. M. Mills to H. R. Denton dated June 27, 1984.

Page 42 deletes the reference to the loss of condenser vacuum scram. The low condenser vacuum scram was deleted from technical specification requirements by TS 204 in July 1985.

Justification for Chan e The low scram pilot air header pressure trip function performs the same protective function as the existing scram discharge volume (SDV) high water level trip. Both trip functions ensure that a reactor scram is initiated while sufficient volume remains in the scram discharge volume to accept discharged water from the control rod drives. For a postulated low air header pressure event where the scram outlet valves leak but do not fully open, the rate at which water could be introduced into the SDV may cause the volume to fill before the high level switches can initiate a trip The low air header pressure switches provide added protection against this scenario.

The proposed amendment would place limiting conditions for operation and surveillance requirements on low air header pressure switches. The scram outlet valves begin to unseat at 43 psig, and thus the proposed setpoint of 50 psig is a conservative trip setpoint. The proposed amendment constitutes additional limitations and testing requirements and therefore does not result in a reduction in safety.

The change to delete the obsolete reference to the low vacuum scram is simply the correction of an error in TS and as such will not compromise nuclear safety.

ENCLOSURE 3 Determination of No Significant Hazards Consideration Descri tion of Amendment Re uest The proposed amendment would revise the technical specifications (TS) of Browns Ferry Nuclear Plant unit 2 to:

l. add the trip level setting, functional test, and calibration testing requirements for the "Low Scram Pilot Air Header Pressure" input to the Reactor Protection System (RPS). This input to the RPS was previously installed as required by NRC bulletin IE 80-17 Supplement 3 as an interim measure for improvement of the scram discharge volume capabilities. TVA has decided to make this modification permanent and has upgraded the input to class 1E requirements.

2. delete the reference to the loss of condenser vacuum scram in the bases of TS 3.1. The low condenser vacuum input to RPS was deleted from TS in July 1985.

3. revise calibration frequency.

Basis for Pro osed No Si nificant Hazards Consideration Determination The Commission has provided standards for determining whether a significant hazards consideration exists as stated in 10 CFR 50.92.(c). A proposed amendment to an operating license for a facility involves no significant hazards consideration if operation of the facility in accordance with the proposed amendment would not: (1) Involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety.

The proposed changes will not significantly increase the probability or consequences of an accident previously evaluated or create the possibility of a new or different kind of accident from any accident previously evaluated because the first proposed change ensures the scram function is accomplished while sufficient volume is available in the scram discharge volume. Also, this instrumentation is class 1E safety grade and will not adversely affect the operability and reliability of any safety related components. For the second proposed change, no change in equipment, systems, components, or structures or operability or surveillance requirements are involved.

The proposed changes will not involve a significant reduction in a margin of safety since for the first change, the instrument will not adversely affect any safety related components, the setpoint provides adequate margin to preclude the event it addresses, and the testing and calibration frequencies are consistent with similar equipment and functions. The second change involves only a correction of an oversight from a previous submittal and is administrative in nature.

The third change is a revision to previously proposed specification changes, reference TVA applications dated August 23, 1984 (TS 199) and December 30, 1985 (TS 199 Supplement 2). The determination of those previous changes proposed by TVA was that they did not involve a significant hazards consideration. The revisions proposed here are conservative with respect to the previous changes. Therefore, we conclude that these revisions do not change the conclusion that no significant hazards consideration is involved.

Also, note that the August 23, 1984 application was prenoticed in the Fedez.al R~e ister, Vol. 49, No. 226, dated November 21, 1984, page Nos. 45975 through 45978. The conclusion of the NRC staff documented in that prenotice was that this involved no significant hazard considerations.

Since the application for amendment involves proposed changes that are encompassed by the criteria for which no significant hazards consideration exists, TVA proposes to determine that. the proposed amendments do not involve a significant. hazards consideration.

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