ML20093L604

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Proposed Tech Spec Table 3.5.1-1, Other-Safety-Related Sys, Reflecting Actual Number of Instrument Channels for Detection of Pressurizer Level.Nshc Determination Encl
ML20093L604
Person / Time
Site: Arkansas Nuclear Entergy icon.png
Issue date: 10/15/1984
From:
ARKANSAS POWER & LIGHT CO.
To:
Shared Package
ML20093L588 List:
References
NUDOCS 8410190079
Download: ML20093L604 (4)
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Text

,

t Tcble 3.5'.1-1 (C:nt'd) _

OTHER SAFETY RELATED SYSTEMS 1

2 3

4 5

No. of.

' Operator Action channels Min.

Min.

-if conditions of No. of, for system

. operable.

degree of column 3 or 4

_ Functional Unit channels-trip channels redundancy cannot be met.

2.

Steam line break instrumentation' 2

1 2

1.

Notes 9, 5 control system (SLBIC)

(a) SLBIC Control & Logic Channels l

3.

Pressurizer level channels 2

N/A 2

1 Note 10 4.

Emergency Feedwater flow 2/S.G.

N/A 1

0 Note 10 channels 5.

RCS subcooling margin monitors 2

N/A 1.

0 Note 10 6.

Electromatic relief valve 2

N/A 1

0 Note 11 flow monitor a

7.

Electromatic relief block 1

N/A 1

0 Note 12 1

valve position indicator 8.

Pressurizer code safety 2/ valve N/A 1/ valve 0

Note 10 valve flow monitors 9.

Degraded Voltage Monitoring (a) 4.16 KV Emergency Bus 2/ Bus 1/ Bus 2/ Bus 0

Note 14 Undervoltage (b) 460 V Emergency Bus

  • 1/ Bus.

1/ Bus 1/ Bus 0

Notes 13, 14 l

Undervoltage 10.

Chlorine Detection Systems 2-1 2

0 Notes 17, 18

  • Two undervoltage relays per bus are used with a coincident trip logic (2-out-of-2) 4 O$0b$hf3 PDR

c f;

.SIGNIFICANT HAZARDS CONSIDERATION (SHC) DETERMINATION This proposed Technical Specification change request.will modify Table

'3.5.1-1.of the ANO-1 Technical Specification. This amendment is necessary so that.the table.will accurately reflect the number of instrument channels

~

to monitor pressurizer level which will be available following the upcoming ANO-1 refueling.. These modifications are being implemented so that AP&L-

may meet ~its' commitments to the NRC. pertaining to IE' Bulletin 79-01B,
10CFR50 Appendix.R, and Regulatory Guide 1.97.

The design change to be

. implemented during.the upcoming refueling will replace the existing system, Tconsisting of three selectable pressure transmitter inputs, with two t'

. independent; instrument channels..The modification will also provide environmentally qualified transmitters and RTDs and provide. channelized safety grade power for'the new instruments.;This proposed change is

. descriptive only and does not affect the minimum number.of channels required

to be operable or the. minimum degrea af redundancy required by the Technical Specification. The change as proposed will leave'the Technical Specification in
compliance:with the B&W Standard Technical Specification and reflect the recommendations for installed post accident monitoring instrumentation outlined in Regulatory Guide 1.97 " Instrumentation for Light-Water-Cooled Nuclear Power Plants to Access Plant and Environs 1 Conditions-During and Following an Accident", in that Regulatory-Guide 1.97

- only requires two channels.

The proposed change is similar to example (vii) found in the April 6, 1983 Federal Register Vol. 48,.No. 67, page 14870 which.was considered not likely

. to involve Significant Hazards Considerations.

The change was determined not to involve a SHC because the operation of Arkansas Nuclear'One Unit 1 in.

accordance with these changes would not:

~ 1.

Involve a'significant incruase.in the probability or consequences of,an accident previously evaluated.

~

2.

Introduce the.' possibility of a previously unanalyzed accident.

3.

-Involve a significant reduction in a margin of safety.

' Bases

. Based'on the above, we conclude that this Technical Specification change does not involve a Significant Hazards Consideration.

I Y

y DISCUSSION OF CHANGE g '

p

~~ Currently pressurizer level is displayed in the ANO-1 control. room through

'the use of-non-nuclear instrumentation.(NNI). -There are currently two pressurizerclevel indications provided:in;the control room', one whose power is supplied from NNI-X,' and another whose power is supplied frca NNI-Y (These two displays will be. referenced as X and_Y indications).

Both of_these 11evel;indicationsiare. temperature compensated through~the use of a dual Lelement'RTD located:in a_ single well in the pressurizer (one of the RTD's is

' powered from X.and the other from-Y).

Uncompensated level is provided by 1;

- three level transmitters whose inputs come from three separate-taps in the

. pressurizer.

~

~Twoifthesetransmitters.arepoweredfromNNI-X,andoneispoweredfrom

NN1-Y.

The X indication'is capable, through the use of manually operated transfer' switches, of being, fed level and temperature signals from any of the_ level and temperature transmitters.

The Y indication is provided inputs

~ ^

solely,from the Y powered' level;and temperature transmitters.

Although the existing three transmitters'are not independent,-Technical Specification Table 3.5.1-1 current 1p. describes this as a three channel ~syste.9.

LTo accommodate the requirements of IE Bulletin 79-01B the level and temperature transmitting' equip;nent located 'in the reactor building must be

replaced during this upcoming outage. In addition, per Appendix R commitments for_ alternate shutdown capability, separate instrument loops, completely independent of the.NNI system, are required for pressurizer level,-

which is considered a_ shutdown parameter._ This modification is also required to be made bi the end of the'ANO-1 sixth refueling.

-Finally in response to Regulatory Guide 1.97, AP&L'has committed to install

- twoiredundant,7 single failure-proof, class 1E instrut..ent loops for -

pressurizer level by the end of the ANO-1 seventh refueling.

-To comply with_these commitments in an integrated 1 fashion, AP&L developed a

= design change package:to be implemented this outage.

In order to comply

with_the redundancy _and single failure proof requirements of Regulatory Guide 1.97, a new well has: to be. secured for a sacond redundant.- RTD.' As there are'no: spare wells available in the pressurizer, one of the three t

' level-taps:must be refitted with an'RTD.

-The level transmitters-and RTDs currently in use are all to be replaced with

. qualified equipment-this. outage.

The design change will also upgrade these y'

instruments.powe'r supplies to class IE standards..These qualified signals

= will:also~ be input to the SPDS this. outage to comply with Appendix R I

commitaents.

Therefore,.although we are reducingLthe overall number of level-transmitters A

'available, we are at the same time significantly improving the reliability fofJthe remaining. equipment.

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.Since we are' improving the reliability of remaining pressurizer level instruments, and since we will continue to comply with the minimum number of instruments required to be operable per the current Technical Specification, we do not believe this change will significantly reduce the margin of safety which currently exists. The Tcchnical Specification, as proposed, also complies with the current B&W generic Technical Specification and Regulatory Guide 1.97.

The complete upgrade of the pressurizer level indication to the control room will not be completed until.the. seventh refueling outage; however, subsequent modifications will not require Technical Specification I

modifications.

L 1

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