ML17251A838

Proposed Tech Specs Allowing Use of New Rod Position Indication Sys

ML17251A838
Person / Time
Site:	Ginna
Issue date:	10/24/1986
From:	ROCHESTER GAS & ELECTRIC CORP.
To:
Shared Package
ML17251A836	List: ML17251A835 ML17251A837 ML17251A838
References
NUDOCS 8611030092
Download: ML17251A838 (36)

Text

Attachment A

Revise the Technical Specification pages as follows:

Remove 3.5-7

3. 10-2

3. 10-7

3. 10 3. 10-9

3. 10-10 3.10-13

3. 10 3. 10-18

3. 10-19 4.1-5

4. 1-6

4. 1-8 Insert

3. 5-7

3. 10-2

3. 10-7

3. 10-8

3. 10-9

3. 10-10 3.10-13

3. 10-14 3.10-14a 3.10-18

3. 10-19 3.10-19a 4.1-5 4.1-6

4. 1-8 SSSioSO0V~

BS>0Z4 PDR ADOCK 05000244

'P PDR

TABLE 3.5-1 (Continued)

Page 2 of 3 6

NO.

FUNCTIONAI UNIT ll.

Turbine Trip 12.

Steam Flow Feedwater Flow Mismatch With Lo Steam Generator Level NO.

OF CHANNELS 3

.-NO.

OF CHANNELS TO TRIP 2

2/loop 1/loop MIN.

OPERABLE CHANNELS 1/loop MIN.

DEGREE OF REDUNDANCY 1/loop OPERATOR ACTION PERMISSIBLE IF CONDITIONS OF BYPASS COLUMN 3 OR 5 CONDITIONS CANNOT BE MET Maintain 50/ of Rated Power Maintain hot shutdown 13.

Lo Lo Steam Generator Mater Level 3/loop 2/loop 2/loop 1/loop Maintain hot shutdown 14.

Vl I

15.

Undervoltage 4 KV Bus Underfrequency 4 KV Bus 2/bus 2/bus 1/bus 1/bus 1/bus 1/bus (both busses) iC Maintain hot shutdown Maintain hot shutdown 16.

Quadrant Power Tilt Monitor (Upper 8 Iower Ex-Core Neutron Detectors) 1 or Iog individual upper 8 lower ion chamber currents once/hr 8 after a load change of 10/ or after 48 steps of control rod motion Maintain hot shutdown

3.10.1.2 When the reactor is critical except for physics tests and control rod exercises, the shutdown control rods shall be fully withdrawn (indicated position).

3.10.1.3 When the reactor is critical, except for physics tests and control rod exercises, each group of control rods shall be inserted no further than the limits shown by the lines on Figure 3.10-1 and moved sequentially with a 100

(+5) step (demand position) overlap between 3.10.1.4 successive banks.

During control rod exercises indicated in Table 4.1-2, the insertion limits need not be observed but the Figure 3.10-2 must be observed.

3.10.1.5 The part length control rods will not be inserted except for physics tests or for axial offset calibration performed at 75% power or less.

3.10.1.6 During measurement of control rod worth and shutdown margin, the shutdown margin requirement, Specification 3.10.1.1, need not be observed provided the reactivity equivalent to at least the highest estimated control rod worth is available for trip insertion and all part length control rods are fully withdrawn.

Each full length control rod not fully inserted, that is, the rods available for trip insertion, shall be demonstrated capable of full',insertion when tripped from at least the 50% withdrawn position (indicated) within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> J

l(

prior to reducing the shutdown margin to less than the limits of Specification 3.10.1.1.

The position of each full length rod not fully inserted, that is, available for trip insertion, shall be determined at least once per 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

3. 10-2 Proposed

3. 10. 2. 12 When the reactor is critical and thermal power is less than or equal to 90% of rated

power, an alarm is provided to indicate when the axial flux difference has been outside the target band for more than one hour (cumulative) out, of any 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period.

In

addition, when thermal power is greater than 90% of rated power, an alarm is provided to indicate when the axial flux difference is outside the target band.

If either alarm is out of service, the flux difference shall be logged hourly for the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> the alarm is out of service and half-hourly thereafter.

3.10.3 3.10.3.1 Control Rod Dro Time While critical, the individual full length (shutdown and control) rod drop time from the fully withdrawn position (indicated) shall be less than or equal to 1.8 seconds from beginning of decay of stationary gripper coil voltage to dashpot entry with:

a.

Tav greater than or equal to 540'F, and avg b.

All reactor coolant pumps operating.

3.10.3.2 With the drop time of any'ull length rod determined to exceed the above limit, restore the rod drop time to within the above limit prior to criticality.

3.10.4 3.10.4.1 Control Rod Grou Hei ht While critical, and except for physics testing, all full length (shutdown and control) rods shall be operable and positioned within + 12 steps (indicated position) of their group step counter demand position.

3.10-7 Proposed

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N

3.10.4. 2 With any full length rod inoperable due to being immovable as a result of excessive friction or mechanical interference or known to be untripable, determine that the shutdown margin requirement of Specification 3.10.1.1 is satisfied within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and be in hot shutdown within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

3.10.4.3 With one full length rod inoperable due to causes other than addressed by 3.10.4.2, above, or misaligned from its group step counter demand position by more than

+ 12 steps (indicated position), operation may continue provided that within one hour either:

3.10.4.3.1 The rod is restored to operable status within the above alignment requirements, or 3.10.4.3.2 The rod is declared inoperable and the shutdown margin requirement of Specification 3.10.1.1 is satisfied.

Operations may then continue provided either:

a.

The remainder of the rods in the group with the inoperable rod are aligned to the same indicated b.

position as the inoperable rod within one hour, while maintaining the limit of Specification 3.10.1.3; or The power level is reduced to less than or equal n

to 75% of rated power within the next one hour, and the high neutron flux trip setpoint is reduced to less than or equal to 85$ rated power within the next, four hours (total of six hours) and the following evaluations are performed:

(i)

The shutdown margin requirement of Specification 3.10.1.1 is determined at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

3. 10-8 Proposed

(ii) A power distribution map is obtained from the movable incore detectors and F~ (Z) and F <H are verified to be within their limits within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

(iii) A reevaluation of each accident analysis of Table 3.10-1 is performed within 5 days; this reevaluation shall confirm that the previously analyzed results of these accidents remain valid for the duration of operation under these conditions.

c. If power has been restricted in accordance with (b) above, then following completion of the evaluation identified in (b), the power level and high neutron flux trip setpoint may be readjusted based on the results of the evaluation provided the shutdown margin requirement of Specification 3.10.1.1 is determined at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

3.10.4.4 With two or more full length rods inoperable or misaligned from the group step counter demand position by more than i 12 steps (indicated position),

be in hot shutdown 3.10.5 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

Control Rod Position Indication S stems 3.10.5.1 While critical, the rod position indication system and the step counters shall be operable and capable of determining the control rod positions within i 12 steps.

3.10-9 Proposed

'P V

II II

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3.10.5.2 With a maximum of one rod position indication per bank inoperable either:

a.

Determine the position of, the non-indicating I

J rod(s)'indirectly by the movable incore detectors at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and,immediately after any motion of the non-indicating rod which exceeds 24 steps (demand position) in one direction since the last determination of the rod's position, or b.

Reduce the power to less than 50% of rated power within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

3.10.5.3 With a maximum of one step counter per bank inoperable either:

a.

Verify that position indication for e'ach rod of the affected bank is operable and that the rods of the bank are at the same indicated position at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, or b.

Reduce the power to less than 50% of rated power within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

Basis The reactivity control concept is that reactivity changes accompanying changes in reactor power are compensated by control rod motion.

Reactivity changes associated with xenon,

samarium, fuel depletion, and large changes in reactor coolant temperature (operating temperature to cold shutdown) are compensated by changes in the soluble boron concentration.

During power operation, the shutdown groups are fully withdrawn 3.10-10 Proposed

i, I

I I

conditions are as follows:

1.

Control rods in a single bank move together with no individual rod insertion differing by more than 25 steps from the bank demand position.

2.

Control rod banks are sequenced with overlapping banks as described in Specification 3.10.

3.

The full length control bank insertion limits are not violated.

4.

Axial power distribution limits which are given in terms of flux difference limits and control bank insertion limits are observed.

Flux difference, is jt qT - qB as defined in Specification 2.3.1.2d.

'The permitted relaxation in F <H with reduced power allows radial power shape changes with rod insertion to the insertion limits. It has been determined that provided the above conditions 1 through 4 are observed, these hot channel factors limits are met.

In Specification 3.10, F

is arbitrarily limited for P ( 0.5 (except for lower power physics tests).

The limits on axial power distribution referred to above are designed to minimize the effects of xenon redistribution on the axial power distribution during load-follow maneuvers.

Basically, control of flux difference is required to limit the difference between the current value of Flux Difference (LI) and a reference value which corresponds to the full power equilibrium 3.10-13 Proposed

value of Axial Offset (Axial Offset = b,I/fractional power).

The reference value of flux difference varies with power level and burnup but expressed as axial offset it varies primarily with burnup.

The technical specifications on power distribution assure that the F~ upper bound envelope of 2.32 times Figure 3.10-3 is not exceeded and xenon distributions are not developed which, at a later time, could cause greater local power peaking even though the flux difference is then within the limits.

The target (or reference) value of flux difference is determined as follows.

At, any time that equilibrium xenon conditions have been established, the indicated flux difference is noted with part length rods withdrawn from the core and with control Bank D more than 190 steps (indicated position) withdrawn.

This value, divided by the fraction of full power at which the core was operating is the full power value of the target flux difference.

Values for all other core power levels are obtained by multiplying the full power value by the fractional power.

Since the indicated equilibrium value was

noted, no allowances for excore detector error are necessary and indicated deviation of 2 5 percent BI is permitted from the indicated reference value.

During periods where extensive load following is 3.10-14 Proposed

required, it may be impossible to establish the required core conditions for measuring the target flux difference every month.

For this reason, two methods are 3.10-14a Proposed

feet out of alignment with its bank) does not result in exceeding core safety limits in steady state operation at rated power and is short with respect to probability of an independent accident.

If instead of determining the hot channel factors, the operator decides to reduce power, the specified 75% power maintains the design margin to core safety limits for up to 1.12 power tilt, using the 2 to 1 ratio.

Reducing the overpower trip set, point ensures that the protection system basis is maintained for sustained plant operation.

A tilt ratio of 1.12 or more is indicative of a serious performance anomaly and a plant shutdown is prudent.

The maximum rod drop time restriction is consistent with the assumed rod drop time used in the safety analyses.

Measurement with T greater than or avg equal to 540'F and with both reactor coolant pumps operating ensures that. the measured drop times will be representative of insertion times experienced during a reactor trip at operating conditions.

II The various control rod banks (shutdown banks, control banks A,B,C, and D) are each to be moved l

as a bank; that is, with all rods in the bank U'ithin one step (5/8 inch) of the bank position.

Position indication is provided by two methods:

a digital count of actuation pulses which shows the

3. 10-18 Proposed

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demand position of the banks and a microprocessor rod position indication (MRPI) system which indicates the actual rod position.

The digital counters are known as the step counters.

Operability of the control rod position indication is required to determine control rod positions and thereby ensure compliance with the control rod alignment and insertion limits.

The 12 step permissible demand to indicated misalignment and the, 0 step rod to rod indicated misalignment ensures that the 25 step misalignment assumed in the safety analysis"is met.

The MRPI system displays the position of all rods on a CRT.

A failure of the CRT would result in loss of position indication of the rods even though the MRPI system is still operable.

Since the MRPI system also transmits rod position information to the Plant Process Computer Syst: em (PPCS),

the PPCS can be used for rod position indication until the CRT is made operable.

The action statements which permit limited varia-tions from the basic requirements are accompanied by additional restrictions which ensure that the original design criteria are met.

Misalignment of a rod requires measurement of peaking factors or a 3.10-19 Proposed

0 1

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'J k1

restriction in power; either of these restrictions provide assurance of fuel rod integrity during continued operation.

Zn addition, those safety analyses affected by a misaligned rod are reevaluated to confirm that the results remain valid during future operation.

References:

(1)

Updated Final Safety Analysis Report (UFSAR)

Section 4.2.

3.10-19a Proposed

TABLE 4.1-1 MINIMUM FREQUENCIES FOR CHECKS g CALIBRATIONS AND TEST OF INSTRUMENT CHANNELS Channel Descri tion 1.

Nuclear Power Range Check S

M*(3)

Cal ibra te D(1)

Q*(3)

Test B/W(2)(4)

P(2)(5)

Remarks

1) Heat balance calcula tion**

2) Signal to AT; bistable action (permissive>

rod stop> trips)

~

3) Upper and lower chambers for axial offset**

4) High setpoint

(<109% of rated po r) 5)

Low setpoint

('<25% of rated power) 2.

Nuclear Intermediate S(l)

Range N.A.

P(2)

1) Once/shift when in service

2) Log level; bistable action (permissive>

rod stop> trip) 3.

Nuclear Source Range S(l)

N.A.

P(2)

1) Once/shift when in service

2) Bistable action (alarm< trip) 4.

Reactor Coolant Temperature 5.

Reactor Coolant Flow S

M(l)

(2) 1 ) Over tempera ture-Del ta T

2) Overpower Delta T

6.

Pressurizer Water Level 7.

Pressurizer Pressure S

, 0 8.

4 Kv Voltage Frequency 0

e 9.

Rod Position fh Indication N.A.

S(1,2)

N.A.

Reactor Protection circuits only

1) With step counters 2)

Log rod position indications each 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> when rod deviation monitor is out of service By means of the movable in-core detector system.

• • Not required during hot> cold> or refueling shutdown but as soon as possible after return to power.

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TABLE 4.1-1 (Continued)

Channel 10.

Rod Position Bank Counters Check Calibrate N.A Test N.A.

Remarks

1) With rod position indication

2) Log rod position indications each 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> when rod deviation monitor is out of service ll. Steam Generator Level S

12. Charging Flow

13. Residual Heat Removal Pump Flow N.A.

N.A.

N.A.

N.A.

14. Boric Acid Tank Level D

N A Bubbler tube rodded weekly

15. Refueling Water Storage Tank Level 16.

Volume Control Tank Level N.A.

N.A.

N.A.

N.A.

17. Reactor Containment Pressure D

M(l)

1) Isolation Valve signal

18. Radiation Monitoring System

19. Boric Acid Control D

N.A N.A.

Area Monitors Rl to R9I System Monitor R17

20. Containment Drain Sump Level N.A.

N.A

21. Valve Temperature 4

Interlocks 0

Q9 22.

Pump-Valve Interlock

23. Turbine Trip Set-Point N.A.

N.A.

N.A.

N.A.

N.A.

M(l)

1) Block Trip

24. Accumulator Level and Pressure N.A.

TABLE 4.1-2 MINIMUM FREQUENCIES FOR EQUIPMENT AND SAMPLING TESTS 1.

Reactor Coolant Chemistry Samples Test Chloride and Fluoride Oxygen Frequency 3 times/week and at least every third day 5 times/week and at least every second day except when below 250 F FSAR Section Reference 2.

Reactor Coolant Boron Boron concentration Weekly 3.

Refueling Water Storage Tank Water Sample Boron concentration Weekly 4.

Boric Acid Tank 5.

Control Rods 6.

Full Length Control Rod Boron concentration Rod drop times of all full length rods Move any rod not fully inserted a sufficient number of steps in any one direction to cause a change of position as indicated by the rod position indication system Twice/week After vessel head removal and at least once per 18 months (1) t1onthly 7

7.

Pressurizer Safety Valves Set point Each Refueling Shutdown 8.

Main Steam Safety Valves

Set point Each Refueling Shutdown 10 9.

Containment.

Isolation Trip Functioning Each Refueling Shutdown

10. Refueling System Interlocks Functioning Prior to Refueling Operations 9.4.5 ll. Service Water System

12. Fire Protection Pump and Power Supply Functioning Functioning Each Refueling Shutdown Monthly 9.5.5 9.5.5

4. 1-8 Proposed

Attachment B

During the Spring 1987 outage the analog rod position indication (ARPI) system will be replaced with a Westinghouse microprocessor rod position indication (MRPI) system.

The ARPI system is being replaced because the system requires significant effort to'aintain alignments, the aging system is becoming prone to component

failures, and spare parts are difficult to obtain.

Also, replacing the ARPI system will resolve human engineering discrepencies raised during the detailed control room design review.

A block diagram of the MRPI system is illustrated on Figure 1.

The system consists of a digital detector assembly for each rod, a

data cabinet located inside containment, and display racks located in the relay room.

Rod position data is displayed on a color CRT in the control room and also transmitted to the plant process computer system (PPCS).

The data cabinet inside containment contains two multiplexers which take rod position information from each of the rods and transmit it to the processors which are in the display racks located in the relay room.

One processor supplies information to the CRT located on the control board, the other processor supplies information to the PPCS.

Both processors are required to produce a turbine runback and block rod withdrawal signal.

The MRPI system senses rod position in intervals of 12 steps for each rod.

The digital detector assemblies consist of 20 discrete coil pairs spaced at 12 step intervals as illustrated on Figure 2.

The MRPI system will normally indicate 0 rod position until the rod goes from the fifth to sixth step.

At that time the indication will normally switch from 0 to 12.

When the rod goes from the seventeenth to eighteenth, the indication will normally switch from 12 to 24.

The rod will normally be within +

6 steps of the MRPI indication, however, if the transition uncertainty of +2 steps is considered the rod will always be within +8 steps of the MRPI indication.

The changes made to the Technical Specifications basically replace references to the ARPI system with references to the MRPI

system, provide clarification whether indicated position or demand positions is required, allow the PPCS to be used as a

backup to the MRPI CRT if the CRT should become inoperable, remove the calibration requirement, and modify the rod movement test.

The detailed changes are described on Table I.

The PPCS backup is used because in the MRPI system if the CRT becomes inoperable, position indication is lost for all rods,

whereas, in the old ARPI system there is one indicator for each rod; an indicator failure would result. in loss of position indication for only one rod.

The safety concerns associated with replacing the ARPI system with the MRPI system are associated with generation of a turbine runback (TR) signal, generation of a block rod withdrawal (BRW) signal, and the ability to comply with the rod misalignment requirement.

The current ARPI system consists of one detector assembly per rod.

The detector assembly is input to an ARPI drawer (one drawer processes two rods).

The ARPI system drawers will sense a

rod bottom for any rod and send an actuating signal to the TR and BRW relays.

The signal from one drawer is required to:generate a

TR and BRW.

The MRPI system consists of one digital detector assembly per rod. All the detector assemblies are multiplexed and become input to two redundant MRPI signal processors.

Each signal processor independently monitors all rods and senses a rod bottom for any rod.

A rod bottom signal from both signal processors is required to generate a TR and BRW.

The two out of two coincident reduces inadvertent TR and BRW but does not effect the accident analysis assumptions.

The rod drop analysis assumes a TR is generated by rod bottom indication from the RPI system or negative flux rate, whichever is more limiting. Failure of a component may prevent a TR from the RPI system but not from the negative flux rate circuitry.

However, failure of a processor or other components in the MRPI system will be annunciated on the main control board.

This condition is the same as the existing ARPI system; failure of the drawer responding to a dropped rod will also not produce a

TR from the position indication system.

However, the redundant negative flux rate TR will still be available in accordance with the safety analysis.

The NRPI system is designed to satisfy the rod misalignment requirement.

The MRPI system determines rod position in 12 step intervals.

The true rod position is always within 28 steps of the indicated position (k6 steps due to the 12 step interval and i2 steps transition uncertainty due to processing and coil sensitivity).'igure 2 illustrates a scenario where a rod becomes stuck at the fourth step.

The NRPI for that rod could be 12.

Since the step counter does not. know the rod is stuck it would continue to count.

The rod deviation alarm will be generated by the PPCS as is currently done for the ARPI system.

The alarm would be generated when the step counter reaches 24 steps (24 steps MRPI indication of 12 steps

= i setpoint of 12 steps).

Therefore, the maximum deviation possible is 24-4 or 20 steps.

This is bounded by the accident analysis which assumes 25 step rod misalignment.

Another possible situation is the rod to rod misalignment within a group or a bank.

This situation is associated with Specifications 3.10.4.3.2a and 3.10.5.3a.

Using Figure 2 as an aid, assume the inoperable rod is at step 4.

The MRPI indication for this rod could be 12 steps.

If the other rods within the group or bank are aligned so that their MRPI indicated position is also 12

steps, the highest actual position for any of these rods would be 19 steps.

Therefore, if the rods are required to have the same indicated position the maximum actual position difference would be 19-4 or 15 steps.

This is bounded by the accident analysis which assumes 25 steps rod misalignment.

Thus, replacing the ARPI system with the MRPI system is acceptable provided Specifications 3.10.4.3.2a and 3.10.5.3a are changed to require the affected rods to be aligned to the same indicated position.

The final safety issue concerns response time for the TR.

The MRPI system processes rod position information several times a second.

Westinghouse has calculated the response time to be approximately one second.

This is less than the calculated response time of the ARPI system.

Since the MRPI response time is faster than the ARPI response time, replacing the ARPI system with the MRPI system does not change the results of the current safety analysis.

Calibration is defined in the current Technical Specification 1.7.1 as "The adjustment, as necessary, of the channel output so that it responds with the necessary range and accuracy to known values of the parameter which the channel monitors".

This definition is inappropriate for a digital system.

Once the MRPI system is installed and the digital detector assemblies positioned the system does not need periodic calibration.

Since drift is not a problem with digital equipment the requirement for periodic calibration above has been removed from Table 4.1-1.

The existing requirements for checking and testing will insure proper functioning of the NRPI system.

The rod movement test (item 6 Table 4.1-2) required modification because rod movement could be checked by the NRPI system with rod movement as small as one step or as large as twelve steps (See Figure 2).

Since rod movement may be checked with less than a

ten step rod motion or as much as twelve step,rod motion the current requirement is no longer appropriate.

In accordance with 10CFR 50.91, this change to the Technical Specifications has been evaluted against three criteria to determine if the operation of the facility in accordance with the proposed amendment would:

l.

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 margin of safety.

The proposed changes do not, involve a significant increase in the probability or consequences of an accident previously evaluated because the MRPI system will indicate rod misalignment within the bounds of current safety analyses, the MRPI system response time is faster than the APRI system, and the response to a control rod drop coincident with a system single failure is essentially the same as that of the ARPI system.

The proposed changes do not create the possibility of a new or different kind of accident from any previously evaluated because the MRPI system provides the same interfaces as the existing ARPI system.

The new processing is digital versus analog.

Failure of NRPI only causes loss of indication which is consistent, with a failure of the APRI system.

The proposed changes do not involve a significant reduction in margin of safety because the existing bounds used in the safety analysis for the ARPI system are applicable to the MRPI system. 'herefore, a no significant hazards finding is warranted for the proposed changes.

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'FIGURE

, MRPI',;

SUBSYSTEM ARCHITECTURE DE TE C.TORS..

B

.,DATA CABINET MANUAL SELECTOR SWITCHES INSIDE CONTAINMENT OUTSIDE CONTAINMENT 8

RGB ALPHA VIDEO VIDEO SUPPORT

'CA,RD 2/2 D/A CONVERTER SURGE SUPPRES-SION DISPLAY RACKS (RELAY ROOM)

CRT CONTROL ROOM MCB TURBINE RUNBACK MCB COMPUTER MUX RELAY ROOM

I

Norael Operation FIGURE 2 XLLUSTRATON OF HRPI INDICATION Stuck Rod actual rod position 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12ll 10 9

8 7

6 5

4 3

2 1

0 step counter 43 42 41

~4 39 38 37 36 35 34 33 32 31 30 29 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12ll 10 8

7 5

4 3

2 1

0 HRPI display 36 24 12 actual rod position 4 (stuck) 3 2

1 0

step counter 43 42 41 Q0 39 38 37 36 35 34 33 32 31 30 29 2Q 27 26 25 24 23 22 21 20 19

'1 17 16 15 14 13 12ll 10 9

8 5

4 3

2 1

0 NRPI display 12 12 12 dotted line indicates transition uncertainty associated with processing and coil sensitivities

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Table 1 Detailed Technical Specification Changes Location Descri tion of Ch e

Reason for Ch e

pg. 3.5-7 item 16 changed 30" to 48 steps with the MRPI system all indications are in step vs inches, 48 steps is ecpivalent to 30 inches.

pg. 3.10-2 section 3.10.1.2 pg. 3.10-2 section 3.10.1.3 pg. 3.10-2 section 3.10.1.6 pg. 3.10-7 section 3.10.3.1 pg. 3.10-8 section 3.10.4.3.2 added "(zndzcated)"

added "(indicated)"

removed "within &+2 steps of" added "the same indicated position as" operator clarification cperator clarification maintain uncertainty within the safety analysis assumption of 25 steps added "(indicated position) "

operator clarification added

"(demand position)"

operator clarification pg. 3.10-9 section 3.10.5.1 pg. 3.10-10 section 3.10.5.2 remove the word "analog" added

"(demand position)"

Pl remove the word "analog" added

"(demand position)"

remove reference to ARPI system operator clarification rerave reference to ARPI system operator clarification

'g. 3.10-10 section'.10.5.3 allows indication to be by the MRPI systen or PPCS maintain uncertainty within the safety analysis assumption of 25 steps replaced, "indicator" with "indication" removed "most witMrawn rod and least withdrawn rcd of the bank are within a maximum of 12 steps of each other'"

added "rods of the bank are at the sane indicated position" pg. 3.10-13 top of page changed 24 to 25 safety analysis assumes 25 steps pg. 3.10-14 middle of page pg. 3.10-14a pg. 3.10-18 page added part of page 3.10-18 is new on page 3.10-19 retyping recpired additional page added "(indicated position)"

operator clarification

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Location Descri tion of Reason for Chan e pg. 3.10-19 to do retyping, part of page 3.10-18 is now on page 3.10-19 linear position indicator replace ARPI with bSPI (LVDT) replaced with micro-processor rod position indication (MRPI) system reference 2 was renoved FSAR, Section 7.3 does not describe the new MRPI system reworded "These are known as the step counters and analog red position indication respectively",

to, "The digital ccunters are known as the step counters".

redundent changed indicators to indication allow indication to be by the MRPI system or PPCS removed "(7.5 inches)"

replaced "15 inches" with "25 steps" with the MRPI system all indications are in steps vs. inches added a discussion on uses of the PECS as backup to CRT aller PECS as backup to CRT pg. 3.10-19a pg. 4.1-5 item 4 updated reference 1

removed reference 2

added note (2) updated reference to UFSAR FSAR, Section 7.3 does not describe the new nmI system this note was inadvertently anitted when this page was re~ for Admend-ment 21 pg. 4.1-5 item 9 changed "Analog Rod Position" to "Rod Position Indication" allow indication to be by the MRPI system or PPCS renove the calibration recpirenents digital systems are not subject to instrum nt drift change "analog rcd positions" to "rod positions indications" aller indication to be by the MRPI system or PPCS

Location Descri tion of Reason for Chan e pg. 4.1-6 item 10 changed "analog red allcw indication to be by position" to "rod position the MRPI system or PECS indication" pg. 4.1-8 item 6 changed "analog rod pos3.'t3.ons" to "rod position indications" changed Test to "Move any rod not fully inserted a sufficient number of steps in any one direction to cause a change of position as indicated by the rod position indication system a minimim movement of 10 steps is inappropriate for the new system.

A rod movement of 1 to 12 steps will cause an indication change on the MRPI system.

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