ML20096A905

Amend 81 to License DPR-22,extending Surveillance Test Intervals & Allowable out-of-service Time Limits for Common Instrumentation Serving RPS & Cis

ML20096A905
Person / Time
Site:	Monticello
Issue date:	04/16/1992
From:	Marsh L Office of Nuclear Reactor Regulation
To:
Shared Package
ML20096A909	List: ML20096A905 ML20096A912
References
NUDOCS 9205110289
Download: ML20096A905 (18)

Text

4 ph AICgIg

+

UNITED STATES NUCLEAR REGULATORY COMMISSION c

p, 5-t WASHING TON, D. C. 20655 t

/

% *****/

NORTHEttN STATES POWER,COMPAhY 000"" "'t. 50-263 HONTICELLO h

.GENERATINf.IfANT

gr AMENDMF,NT TO FACILITY OPERATING LICENSE Amendment No. 81 License No. DPR-22 1.

The Nuclear Regulatory Comission hhe Comission) has found that:

A.

The applicativ< for amendment by Northern States Power Company (the licensee)datedOctober 22, 1991, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act),

and the Commission's rules and regulations set forth in 10 CFR Chapter I; B.

The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.

Thereisreasonableassurance(1)thattheactivitiesauthorizedby this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Comission's regulations; D.

The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.

The issuance of this amendment is in accordance with 10 CFR Part 51 of the Comission's regulations and all applicable requirements have been satisfied.

2.

Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C.2 of Facility Operating License No. DPR-22 is hereby amended to read as follows:

l I

l l

9205110289 920416 PDR ADOCK 05000263 P

PDR

... _ _ _ _ - ~.

..______._-.____.._.~___.______.__.m.__

4 2

Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No.81, are hereby incorporated in the license.

The ldcensee shall operate the facility in accordance with the Technical Specifications.

3.

This license amendment is effective as of its date of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION f

hte L. B. Marsh, Director Project Directorate III.1 Division of Reactor Projects-!!!/IV/V Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical-Specifications Date of Issuance: April 16, 1992 l:

L-

,__.._m..

.._..._.a.~.....,_.

~ _...

a ATTACHMENT TO LICENSE AMENDMENT NO. 81 FACILITYOPERATINGLICENSENO.PLR-22 DOCKET NO 50 263 Revise Appendix A Technical S >ecifications by removing the pages identified below and inserting the attacled pages. The revised pages are identified by amendment number and contain marginal lines indicating the area of change.

REMOVE INSET 27 27 27a 29 29 32 32 33 33 34 34 35 35 39 39 41 41 42 42 51 51 61 61 62 62 64 64 72 72

n,

~

~ '

~ (

.dj

_ ' 9. ",4

?; e p:

.; j' g,.

~

y g'

",.Q; srj x

s-

,y

. qq. -

9

-;y

.q

., (1 g,,.

Yl(*;

E

- p.;

s.. O

?.

s 3

f.

~

3.0 LIhITING CONDITIONS FOR OPERATION 4.0 SURVEIL'#

B. Upon discovery that the requirseints for the B.

{ DELETED) nur.aer of operable or ' operating. trip systems or insLcument channels are not satisfied, action shall be initiated as follows:

1. With one required instrument channel inoperable in one or more trip functions, place the inoperable. channel (s) or trip system in the tripped condition within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, or

2. With more than one instrument channel inoperiale for one or more trip functions, immediately sat sfy the minimum requirenents i

by placing appropriate chsnnel(s), or trip i

system (s) in the tripped condition, or 3.

Place and maintain the plant under the specified required conditions using normal operating procedures.

3.1/4.1 27 Amendment No. 29, 81 3

m.

.e,

3.0 LIMITING CONDITIONS FOR' OPERATION 4.0 SURVEILIANCE REX 2UIREMENTS -

C.

'RPS Power Monitoring System

'C.

RPS Power Monitoring yster 1.

Except as specified below, both channels 1.

Instrument Functional Tests of each RPS of the' power monitoring system for.the MG-power monitoring channel shall be set'or altenate source supplying each performed at least once every six months.

reactor protection system bus shall be

^

operable with the following setpoints:

2.

At least once each Operating Cycle an Instrument Calibratfon of each RPS power.

Time Delav monitoring channel shall be performed to a.

Over-voltage

- s128 VAC s4 seconds verify over-voltage, under-voltage, and

b. -Under-voltage

- 2104 VAC 54 seconds under-frequency setpoints.

c.

Under-frequency - 257 HZ s4 seconds

2. -With one RPS electric power monitoring hannels for the MG set or alternate

~

t source supplying each reactor protection system bus inoperable, restore the inoperable channel to Operable status within 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or' remove the associated RPS MG set.or alternate' power supply _from service.

3.

With both RPS electric power monitoring channels for the MG set or alternate source supply' g each reactor. protection system bus inoperable, restore et least one to Operable status within 30 ninutes or remove the associated EPS MG set cr alternate power supply from service.

3.1/4.1 27a l

Amendment No. 81'

f TABLE 3.1.1 - CONTINUED Modes in which func-Total No. of Min. No. Operable tion must be Oper-Instrument or Operating Instru-Limiting able or O

. Trip Function Trip Settings Refuel (3)peratin&**

Channels per ment Channels Per Required

. Startup Run~

Trip. System Trip System (1)-

Conditions *-

10. Main Steamline s 10 X Normal High Radiation background at (See Note 9) rated power X

X(f)

X(f) 2-2

.A

11. Main Steamline s los Valve Isolation Valve Closure closure

• ib)

X(b)

X 8

6 A or C

12. Turbine Control Valve Fast Closure (See Note 7)

X(d.f) 2 2

.D

13. Turbine Stop s 10% Valve Valve Closure Closure X(d) 4 4

D H@lS.1 1.

There shall be two operable or tripped trip systems for each function. A channel maybe placed in an inoperable l

status for up to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> for required surveillance without placing the trip. system in the tripped condition.

provided that at Isast one other. operable channel in the same trip system is monitoring that parameter.

2.

For an IRM channel te be considered operable, its detector shall be fully inserted.

3.

In the refueling mode wits the reactor suberitical and reactor water temperature 1

. than 212* F, only the following trip function: need to be operable: (a) Mode Switch in Shutdown, (b) Manual Scram, (c) High Flux IRM, (d) Scram Discharge Volume High Level.

}

4.

Not required to be operable when primary. containment integrity is not required.

5.

Tc be considered operable, an APRM must have at least 2 LPRM inputs per level and at least a to' il of 14 LPRM inputs, except that channels 1, 2, 5, and 6 may lose all LPRM inputs from the companion Afa3 Cabanet plus aka additional LPRM inpur and still be considered operable.

3.1/4.1 29

' Amendment No. 59, $3, 81

~

TABLE 4.1.1-SCRAM INSTRUMENT' FUNCTIONAL TESTS MINIMUM FUNCTIONAL TEST FREOUENCIES FOR SAFETY INSTRUMENTATION AND CONTROL CIRCUITS INSTRUMENTATION CilANNEL FUNCTIONAL TEST MINIMUM FREOUENCY (4) liigh Reactor Pressure Trip Channel and Alarm Quarterly illgh Drywell Pressure Trip Channel and Alarm Quarterly low Reactor Water Level (2, 5)

Trip Channel and Alarm Quarterly High Water Level in Scram Discharge Volume Trip Channel and Alarm Quarterly Conder..

Low Vac Trip Channel and Alarm Once each month

' Main' Steam Line Isolation Valve Trip Channel and Alarm

. Quarterly Closure Turbine Stop Valve Closure Trip Channel and Alarm Quarterly Manual, Scram Trip Channel and Alarm Weekly Turbine Control Valve Fast Closure Trip Channel and Alare Quarterly APRM/ Flow Reference (5)

Trip Output Relays Quarterly IRM (5)

Trip Channel and Alarm

. Note 3 4

111gh ' Steam Line Rad. (5)

Trip Channel and Alarm Quarterly l

Mode Switch in Shutdown Place mode switch in Each refueling outage a

shutdown 1

3.1/4.1 32 Amendment No. 19, 53, $$, 81 u

'4 TABLE 4;1.1'(Continued)'

Note 1:

Dele ted.'

Note 2:. A sensor check shall be performed on ' low reactor water Llevel. once per. day and on high steam line radiation once per shift.

i Note 3:

Perform functional' test prior to every startup,cand normal shutdown.

Note 4:

Functional tests are not required when the systems are not required to be operable or.

nre trippad.

If tests are missed, they shall be" performed prior to returning the-systems to an operable _ status.

Note 5: A functional test of this instrument means the injection of. a simulated signal into the instrument (not primary ser.sor) to verify the proper instrument channel response, alarm, l

and/or initiating action.

i r

t 3.1/4.1 33 Amendment No. $3, 81

aw TABl.E 4.1,2 SCRAM INSTRUMENT CALIBRATION ti?NIMUM CALIBRATION FREOUENCIES FOR REACTOR PROTECTION INSTRUMENT CllANNELS INSTRUMENT CHANNET, CROUP CALIBRATION METHOD MINIMUM FREOUENCY R APRM B

lleat Balance.

Once every 3 days (4)

IRM B

fleat Balance See Note 1 High Reactor Pressure A

Pressure Standard Every 3 months liigh Drywell Pressure A

Pressure Standard Every 3 months Low Reactor Water B

Pressure Standard' Every Operating Cycle -

Transmitter Every 3 months -

Trip Unit liigh Water Level in Scram Discharge A or B Water Level Every 3 months Condenser Low Vacuum A

Vacuum Standard Every 3.. months-liigh Steam Line Radiation B

See Note 3 See Note 3 Main Steamline Isolation Valve Closure A

Observation Etery Operating Cycle Turbine Control Valve Fast Closure A

Pressure Standard Every 3 months-Turbine Stop Valve Closure A

Observation Every Operating Cycle Recirculation Flow Meters 6 Pressure Standard Every 3 months Flow Instrumentation U.2.te s :

1.

Perform calibration test duris3 every startup and normal shutdown.

2.

Calibration tests are not required when the systems are not required to be operable or are tripped.

If tests are missed, they shall be performed prior to returning the systeus to an operable status.

3.

This instrument will be calibrated every three months by means of a bui'Lt-in current source, and each refueling' outage with a known radicactive source.

4.

This calibration is performed by taking a heat balance and adjusting the APRM to agree with the heat balance. Alarms and trips will be verified and calibrated if necessary during funccional testing.

L

• GROUPS:

A.

Passive type devices.

B.

Vacuum tube or semiconductor devices and detectors that drift or lose sensitivity.

3.1/4.1 34 -

Amesidment No. J. JI, 66. 81

6 Bases:

3.1 The reactor protection system automatically initiates a reactor scram to:

7.

preserve the integrity of the fuel cladding; 2.

preserve the integrity of the primary _ system barrier; and 3.

minimize the energy which must be absorbed, and prevent criticality following a loss of coolant accident.

This specification provides the limiting conditions for operation necessary to preserve the ability of the system'to-telerate single failures and still perform its intended function.

The reactor protection system is of the dual channel type.

Ref. Section 7.7.1 FSAR. The system is made up of two-independent trip systeas, each having three subchannels or tripping devices. One of the three subchannels has inputs from the manual scram push buttons and reactor mode switch.

Each of the two remaining subchannels has an input'from at least one independent sensor which monitors each critical parameter.

The outpu~s of these subchannels are combined in a 1 out of 2 logic; i.e.,

an input signal on either one or ooth of the subchannels will cause a trip system trip.

The outputs of the trip systems are arranged so that a trip on both systems is required to produce a reactor scram.

This system meets the intent of the proposed IEEE Standard for Nuclear Power Plant Protection Systems issued Sept. 13, 1966. The system has a reliability greater than that of a 2 out of 3 system and somewhat less than that of a 1 out of 2 system.

Ref. APED 5179.

The required conditions dhen the: minimum conditions.are not met are chosen so as to bring plant opera-tion promptly to such a condition that the particular protection instrument is not required; or the plant is placed in the protection or safe condition tbst the instrument initiates. This is accom-plished in a normal manner without subjecting the plant to abnormal operating conditions.

[

l When the minimum requirements for the number.of operable or operating trip systems and instrumenta-tion channels are satisfied, the effectiveness of the protection system is preserved; i.a.,

the system can tolerate a single failure and still perform its intended function of scramming the reactor.

3.1 BASES 35 Amendment No. 81

~

Bases Continued:

3.1.

The.1RMs are calibrated by the. heat balance' method such that.120/125 of full scale on the highest IRM range is below 20% of rated r.eutron flux (see Specification 2.3.A.2).

The reouirement.that the IRM detectors be inserted 'in the core assures that the heat balance calibration is not invaliuited by the withdrawal of the detector.

Although the operator will set the. set points within the trip settings specified on Table 3.1.1, the actual values of the various set points'can differ appreciably from the-value the operator is attempting to set..The deviations could be caused by inherent instrument error, operator setting error, drift of the set point, etc.

Therefore, such deviations have been accounted for in the various transient analyses and the actual trip settings may vary by the following amounts:

Trio Function Deviation Trio Funcilon Deviation

3. High Flux IRM

+2/125 of scale

47. Reactor Low Water

-6 inches Level

5. High Reactor Pressure

+10 psi

n. Scram Discharge Volume

+1 gallon High Level

6. High Drywell Pressure

+1 psi

9. Turbine Condenser Low

-1/2 in. Hg Vacuun

• This indication is reactor coolant temperature sensitive. The calibration is thus made for rated condi tons.

The level error at low pressures and temperatures is bounded by the safety analysis which reflects the weight-of-coolant above the loser tap, and not the indicated level.

A violation of this specification is assumed to occur only when a device is knowing 1v set outside of the limiting trip setting, or a sufficient number of devices have been affected, any means such that the automatic function is incapable of operating within the allowable deviation while in a re-actor mode in which the specified function must be operable, or the actions specified in 3.1.B are l

not initiated as specified.

If an unsafe failure is detected during surveillance testing, it is emsirable to determine as soon as possible if other failures of a similar type have occurred and whether the particular function in-volved is still operable or capable of meeting the single failure criterion. To meet the require-ments of Table 3.1.1, it is necessary that all instrument channels in one trip system be operable 3.1 BASES 39 Amendment No. SD, 66, 76,1 81

D Bases:

4.0 This specification provides that surveillance activities necessary to ensure the Limiting Cond".tions for Operations are met and will be performed during the periods when the Limiting Conditions for Operation are applicable.

A tolerance for performing surveillance activities'beyon( rar

'iminal' interval is provided to allow operational flexibility because of scheduling and performance considerations. The plant uses a fixed surveillance program that prevents repetitive addition of the allowable 25% extension..Each surveillance test is completed within plus or minus'25% of each scheduled fixed dated. Scheduled dates are based on divioing each calender. year into four 13-week " surveillance" quar:ers constating' of 3 4-week " surveillance" months and one." catch-up" week.

This method of scheduling pereits certain tests.always to be scheduled on certain days of the week.

The specification ensures that surveillance activities associated with a Limiting Condition for Operacion have been performed within the specified time interval prior to entry into a plant condition for which the Limiting Condition for Operation is applicable. Under the terms of this specification, for example, during-initial plant startup or following extended plant outage, the surveillance activities must be peri'ormed within the stated surveillance interval prior to placing or returning the system or equipment to Operable status.

4.0 BASES 41 Amendment No. 63, 81

%-5 a

~

Bases:

4.1 Une instrumentation in t'ds section will be functionally tested and calibrated'at' regularly

' scheduled intervals. Lpecific surveillance intervals and surveillance and maintenance outage times have been determined in accordance with NEDC-30851P,." Technical Specification ImprovementfAnalysis for BWR Reactor Protection-System," as approved.by the NRC and documented in the SER dated

. July 15, 1987.(letter to T A Pickens~from A Thadani).

Calibration frequency of the instrument channel is divided into two groups as defined on Ts'le o

4.1.2.

Experience with passive type instruments indicates that a yearly calibration isLadequate. Where possible, however, quarterly calibration is performed.

For those devices which employ amplifiers etc., drift specifications call for drift to be less than 0.51/ month; i.e.,

in the period of a month a drift of 0.5% would occur and thes provide for' adequate margin. For the' APRM system, drift of electronic apparatus is not the only consideration in determining a calibration frequency.

Change in powar distribution and loss'of chamber sensitivity dictate a calibration every three days.

Cs11bration on this frequency assures plant operation at or below thermal limits.

44.1 BASES 42 NEXT PACE IS 45 Amendment No.-63, 81 1

Tablo.3.2.1 - Continued

~

NOTES:

.(1)

For Groups 1, 2 and 3, there shall be two operable or tripped trip. systems for each function. A channel may be

~

placed in'an' inoperable status for up to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> for required surveillance without placing the trip system in the

. ripped condition provided that at least one other operable channel in the same trip system is monitoring that parameter.

For Groups 4, 5 and Reactor Pressure Interlocks there shall be two operable or tripped trip systems for each function.

'(2)

For Croups 1, 2 and 3, upon discovery that minimum requirements for the number of operable or operating trip systems or instrument channels are noe satisfied action shall be initiated as follows:

(a)- Witit one required instrument channel operable in one or more trfp functions, place the inoperable chennel(s) or' trip system in the tripped condition within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, or

.(b) With more than one' instrument channel inoperable for one or more trip functions, immediately satisfy the requirements by placing appropriate channels or systems in the tripped condition, or (c) Place the. plant under the specified required conditions uring normal operating procedures.

For Groups 4, 3 and Reactor Pressure Interlocks upon discovery that minimum requirements for the nut...

sf operable or operating trip systems or instrument channels are not satisfied action shall be initiated to:.

(a) Satisfy the requirements by placing appropriate channels or systems in the tripped condition.

f (b) Place the plant under the specified required conditions using normal operating procedures.

(3)

Low pressure in main steam line only.need to be available in the RUN position.

(4)

All instrument channels are shared by both trip systems.

(5)

May be bypassed when necessary only by closing the manual containment isolation valves during purging for containment inerting or de-inerting. Verification of the bypass condition shall be noted in the control room log. Also, need not be operable when primary containment integrity is not required.

Required conditions when minimum conditions for operation are not satisfied.

A.

Group 1 isolation valves closed.

B.

Reactor Power on IRP range or below and reactor in startup, refuel, or shutdown mode.

C.

Isolation Valves closed for: Shutdevn Cooling System, and Reactor Head Cooling Line.

D.

Comply with Condition C. above.

E:

Isolation Valves closed.for: Reactor Cleanup System, F.

HPCI steam line isolated.

(See specification 3.5 for additional requirements.)

j G.

RCIC steam line isolated.

3.2/4.2 51 REV Amendment N5. 81

Table 4.2.1 Hinimum Test and Calibration Frequency for Core Ceoling Rod Block and Isolation Instrumentation Instrument Channel Test (3)

Calibration (3)

Sensor Check (3) t:CCS INSTRUMENTATION 1.

React.tsr Low-Low Water Level Once/ month (Note 5)

Every Operating Cycle - Transmitter Once/3 months -

Trip Unit once/ Shift 2.

Drywell liigh Pre sure once/ month once/3 months None 3.

Reactor Low Pressure (Pump Start)

Once/ month once/3 months None 4

Reactor Low Pressure (Valve Permissive)

Once/ month once/3 months None 5.

Undervoltage Emerger.cy Bus Refueling Outage Refueling Outage None

['

6.

Low Pressure Core Cooling Pumps Discharge Pressure Irterlock Once/ month Once/3 months None 7.

Loss of-Auxiliary Power Refueling Outage Refueling Outage None 8.

Condensate Storage Tank Level Refueling Outage Refueling Outage None 9.

Reactor liigh Water Level once/ month (Note 5)

Every Operating Cycle - Trensml.tter Every 3 months -

Trip Unit Once/ Shift Bf dlEK1 1.

APRM Downscale Once/ month (dote 5)

Once/3 months None 2.

APRM Flow variable Once/ month (Note 5)

-Once/3 months None 3.

IRM Upscale Notes (2,5)

Note 2 Note 2 4.

IRM Downscale Notes (2,5)

Note 2 Note 2 5.

RBM Upscale once/ month (Note 5)

Once/3 moaths None 6.

RBM Downscalc Once/ month (Note 5)

Once/3 months None 7.

SRM Upscale Notes (2,5)

Note 2 Note 2 8.

SRM Detector Not-Full-In Position Notes (2,9)

Note 2 None 9.

Scram Discharge Volume-liigh Level Once/3 months Refueling outage None M_AIN STEAM LINE '(CR0 iip 1) ISOLATION 1.

Steam Tunnel High Temperature Refueling Outage Refueling Outage Non3 2.

Steam Line High Flow Once/3 months once/3 Months once/ Shift

.j 3.2/4.2 61 Amendment no. 2, 10, 37, 39, 53, EE, 81

1 Table 4.2.1 - Continued

^

Minimum To:!t and Calibration' Frequency For Coro Cooling Rod Block and Tsciatinn'Instrementation Instrument Channel Test (3)

Calibration (3)

Sensor Check (3).

3.

' Steam Line' Low Pressore.

Once/3 nonths once/3 months None-

.4.

Steam Line High Radiation Once/3 months.(Note 5) Note 6 Once/ shift 5.

Reactor' Low Low Water Level.

Once/2 n.onths (Note'5) Every Operating Cycle-Or ce/ shift.

Transmitter.

Once/3 Months-Trip Unit CONTAINMENT IS0lATION (CROUPS 2 6 3) 1.

Reactor Low' Water' Level (Note 10) 2.

Drywell High Pressure (Note 10).

11PCI (CROUP 4) IS01ATION -

1.

Steam Line liigh Flow Once/ month once/3 months None 2.

Steam Line'liigh Temperature Once/ month once/3 months None RCIC (CROUP 5) ISOIXrION 1.

Stearn Line High Flow once/ month once/3 months None 2.

Steam Line liigh Temperature Once/ month Once/3 months None REACTOR BUI' DING VEUTTIATIO,J,1 1.

Radiation Monitors (Plenum)

Once/ month once/3 months once/ day 2.

Radiation Monitors (Refueling Floor)

Once/ month Once/3 months Note 4 FJEGIRCUIATION PUMP TRIP AND ALTEMNATE ROD INJECTION 1.

Reactor liigh Prescure Once/ month (Note 5)

Once/ Operating Cycle-Once/ Day Transmitter once/3 Months-Trip Unit 2.

Reactor Low Low Water Level Once/ month (!!ote 5)

Once/ Operating Cycle-One.e/ shift Transmitter Once/3 Months-Trip Unit

$11UTDOWN COOLING SUPPLY ISOIATION 1.

Reactor Pressure Interlock once/ month once/3 Months None 3.2/4.2 62 Amendment No. T/, 46, F1, 67, 66,,

/jl,81

~

l

/

reactor scram, protect veof accidents i

consequences it which initiater amitigate the operator error before of tion ditior.s tection instrumenta action to single addition to reactor pro rovided which initiatescontrol, or terminai.erovides the limiting c a

l};tses.

emergency coreassure the l

ability toset of specifications p instrumentation has been poperators This

function, of tha cribe the trip settings (1) to In initiation 3.2 are of the Specificationsrequired, and (ii) to presalso provid h

which are beyond t e iting consequences.

iw ry system isolationobjectives serious results in The when operation for the prlated functions.instrumentationset of Specificarious isuncnt and must benot exceeded ocring and other safety re This of the protectiveadequate performance.ntrol rod block systern.netrate the effectiveness shown.in are tion required toof operation for the co those lines that pe assure radiation dose limits must be protective instrumenta Such instrumentationis to isolate the prim that the conditions valves are installed inof coolant accident soval*~ s is initiated byrequired.

of these isclation is objective accident.

Isolation The Isolated during a loss Actuationconditions for which required. exceeded during an arrangement.

integrity is accident condition.

he a dual bus tainmentof 10 CFR 100 are not connected in Table 3.2.1 which senses twhenever primary conuidelines an applicable here.

ry system isolation isification 3.1 is avallablecontainment so that the g 0'6* (7" nn which initiates primain the bases for Spec reactor water levet is 1 initiates This trip 2 FSAR.

For The instrumeC ationthe discussion given tation 12bove the top of the active fuel. Reference Section 7.7.2.

perforation set to trip when will be closed beforeadequate.

water level instrumen

Thus, valves.

100t vated thermal power) aary containment active ing is isolation valves fuel, theand therefore the sett w reactor

'6" above The lo of group

'6" aus..e the top of tbreak in that reactor water level is 6 the In trument at2, ano he line isolation s

containtment ncy a trip setting of 10even for the maximurn tion is set to tr pof the Group 1 Prirnaryand starts the emerge closure i when clad occurs ms water level instrumentainitiates activates the ECC syste closure of the This trip nd also The low low reactoractive fuel. tion 7.7.2.2 FSAR, a the top of the valves, Reference Sec diesel generator.

64 No. M, 81 Amendment

-Bases:

3.2 Ia addition to. reactor protection instrumentation which initiates a reactor scram, protective instrumentation has been provided which initiates action to mitigate the consequences of accidents

- which are beyond the operators ability to control, or terminate a single operator error befere it results in serious consequences. This, set of-specifications provides the limiting conditions of operation for the primary system isolation function, initiation of;the emergency core cooling system, and other safety,related functions.

The objectives of the Specific tions are' (1) to assure the effectiveness of 'the protective instrumentation when required, and 11) to prescribe the trip settings l

required to assure' adequate performance..This set of Specifications also provides the limiting conditions lof operation for the. control rod block system.

Isolation valves are installed in those. lines that penetrate the primary containment and must be-isolated durir.g a loss'of coolant accident so that the radiation dose limits'are not exceeded during-an accident condition. Actuation of these valves is initiated by protective instrument tion shown in Table 3.2.1 which senses the conditions'for which isolation is required. Such instrumentation must be available whenever primary containment integrity is required.

The objective is to isolate the primar~

containment so that the guidelines of 10 CFR 100 are not exceeded during an accident.

The instrumentation which initiates primary system isolation is connected in a dual bus arrangement.

Thus, the discussion given in the bases for Specification 3.1 is applicable here.

The low reactor water level instrunentation is set to trip when reactor water level is 10'6" (7" on the instrument at 100% rated thermal power) above the top of the active fuel. This trip initiates closure of group 2, and 3 primary containment isolation valves.

keference Section 7.7.2.2 FSAR.

For

~

a trip setting of 10'6" above the top of the active fuel, the valves will be closed before perforation of the clad occurs even for the maximum break in that line and therefore the setting is adequate.

The low low reactor water level instrumentation is set to trip when reactor water level is 6*6" above the top of the active fuel. This trip initiates closure of the Group 1 Primary containmant isolation valves, Reference Section 7.7.2.2 FSAR, and also activates the ECC systems and starts the emergency diesel generator.

3.2 BASES 64 Amendment No. 65, 81

4 Bases:

4.2 The instrumentation in this section will be functionally teated and calibrated at regularly scheduled intervals. Although this instrumentation is not generally considerad to be as important to plant safety as the Reactor Protection Syster, the same design reliability goal 2 ate applied. As discussed in Section 4.1 !$ases, monthly or quarterly testing' is generally specified unless the testing must be conducted during j '

refueling outages. Quarterly calibration is specified unless the calibration must be conducted during refueling outages. Where applicable, sensor checks are specified on a once/ shift or one/da.v basir.

s 4.2 BASES 72 NEXT PAGE IS 76 Amendment'No. 63. 81

.