ML20214U696

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Proposed Tech Specs,Consisting of Proposed Change 87-10, Revising Operability Requirements of Control Rod Block Actuation Instrumentation to More Closely Correspond to Logic Design
ML20214U696
Person / Time
Site: Pilgrim
Issue date: 06/02/1987
From:
BOSTON EDISON CO.
To:
Shared Package
ML20214U656 List:
References
NUDOCS 8706110301
Download: ML20214U696 (7)
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LIMITING CONDITION FOR OPERATION SURVEILLANCE REQUIREMENT C. Control Rod Block' Actuation C. Control Rod Block Actuation

1. The limiting conditions of - 1. Instrumentation shall be operation for the instrumentation functionally tested, calibrated that initiates control rod block and checked as indicated in Table are given in Table 3.2.C-1. The 4.2.C.

trip setpoints for this

., instrumentation shall be set System logic shall be

'.? consistent with Table 3.2.C-2. functionally. tested as indicated in Table 4.2.C.

D. ' Radiation Monitoring Systems - D. Radiation honitoring Systems -

1 Isolation & Initiation Functions Isolation & Initiation Functions

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1. Reactor Building Isolation and 1. Reactor Building Isolation and-Control System and Standby Gas Control System and Standby Gas Treatment System Treatment System The limiting conditions-for Instrumentation.shall be operation are given in Table functionally tested, calibrated

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3.2.D. and checked as indicated in Table 4.2.D.

System logic shall be--

functionally tested as indicated

-in Table 4.2.0.

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. . . / . -TABLE 3.2.C-1

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INSTRUMENTATION THAI _ INITIATES CONTROL ROD BLOCKS Minimum Operable Channels Required Trio Function per Trio Function Operational Conditioni Action APRM Upscale (Flow Biased) 4 Run/Startup/ Refuel (1).

APRM Inoperative 4 Run/Startup/ Refuel (1)

APRM Downscale 4 Run (1)

Rod Block Henitor (Flow Biased) 2 Run, except trip is bypassed when (1) (2) reactor power is 130%

1 Rod 61eck Monitor Inoperative 2 Run, except trip is bypassed when (1) (2) reactor power is 130%

Rod Block Monitor Downscale . 2 . Run, except trip is bypassed when (1) (2) reactor power is i 30%

IRM Downscale 6 Startup/ Refuel, except trip is (1) bypassed when IRM is on its lowest range IRM Detector not in Start; , -sitt^^ 6 Startup/ Refuel, trip is bypassed -(1) when mode switch is placed in Run IRM Upscale 6 Startup/ Refuel (1)

IRM Inoperative 6 Startup/ Refuel (1)

SRM Detector not in Startup Position 3 Startup/ Refuel, except trip is bypassed (1) when SRM count rate is 1 100 counts /second or IRMs on Range 3 or above (4)

SRM Downscale 3 Startup/ Refuel, except trip is bypassed (1) when IRMs on Range 3 or above (4)

SRM Upscale 3 Startup/ Refuel, except trip is bypassed (1) when the IRM range switches are on Range 8 or above (4)

SRM Inoperative 3 Startup/ Refuel, except trip is (1) bypassed when the IRM range switches are on Range 8 or above (4)

Scram Discharge Instrument Volume Water Level - High 2 Run/Startup/ Refuel (3)

Scram Discharge Instrument Volume - Scram Trip Bypassed 1 Run/Startup/ Refuel (3)

Recirculation Flow Converter - Upscale 2 Run (1)

Recirculation Flow Converter - Inoperative 2 Run (1)

Recirculation Flow Converter - Comparator Mismatch 2 Run (1)

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Notes for Table 3.2.C-1

1. With the number of operable channels:
a. One less than required by the minimum operable channels per trip

-function requirement, restore'an inoperable channel to operable status within 7 days or place an inoperable channel in the tripped condition within the next hour.

b. Two or more less than required by the minimum operable channels per trip function requirement, place at least one inoperable channel in the tripped condition within one hour.
2. The minimum operable channels for the rod block monitor trip function may be reduced by one for maintenance and/or testing, provided that this condition does not last longer than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in any thirty day period.
3. If the number of operable channels is less than required by the minimum operable channels per_ trip function requirement, place the inoperable channel-in the tripped condition within one hour.
4. SRM operability requirements during core alterations are given in Technical Specification 3.10.

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TABLE 3.2.C-2 CONTROL ROD BLOCK INSTRUMENTATION SETPOINTS Trio Function Trio Setooint APRM Upscale 1 (0.58 W + 50%) ~ FRP ~ (1)

(Flow Biased) _MFLPD_

APRM Inoperative Not Applicable APRM Downscale 12.5 Indicated on Scale Rod Block Monitor 1 (0.65 W + 42%) ~ FRP ~ (1)

(Flow Blased) _MFLPD_

Rod Block Monitor Inoperative Not Applicable Rod Block Monitor Downscale 15/125 of Full Scale IRM Downscale 15/125 of Full Scale IRM Detector not in Not Applicable Startup Position IRM Upscale i 108/125 of Full Scale IRM Ir. operative Not Applicable SRM Detector not in Not Applicable Startup Position SRM Downscale 1 3 counts /second SRM Upscale i 10 5 counts /second SRM Inoperative Not Applicable Scram Discharge Instrument Volume _118 gallons Water Level - High Scram Discharge Instrument Volume - Not Applicable Scram Trip Bypassed Recirculation Flow Converter - Upscale i 120/125 of Full Scale Recirculation Flow Converter - Inoperative Not Applicable Recirculation Flow Converter - Comparator i 10% Flow Deviation for > 80% Rated Power, and Mismatch 1 15% Flow Deviation .for i 80% Rated Power (1) W is the percent of drive flow required to produce a rated core flow of 69 Mlb/hr.

Trip level setting is in percent of design power (1998 MWt). For flows of 100% or greater, the rod block monitor maximum trip level setting shall be 107% power.

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PNPS TABLE 4.2.C MINIMUM TEST AND CALIBRATION FREQUENCY FOR CONTROL ROD BLOCKS ACTUATION Instrument Channel Instrument Functional Calibration Instrument Check' Test APRM - Downscale (1) (3) Once/3 Months Once/ Day APRM - Upscale (1) (3)- Once/3 Months Once/ Day APRM - Inoperative (1) (3) Not Applicable Once/ Day IRM - Upscale (2) (3) Startup or Control Shutdown (2)

IRM - Downscale (2) (3) Startup or Control Shutdown (2)

IRM - Inoperative (2) (3) Not Applicable (2).

RBM - Upscale (1) (3) Once/6 Months Once/ Day RBM - Downscale (1) (3) Once/6 Months Once/ Day RBM - Inoperative (1) (3) Not Applicable Once/ Day SRM - Upscale (2) (3) Startup or Control Shutdown (2)

SRM - Inoperative (2) (3) Not Applicable (2)

SRM - Detector Not in Startup Position (2) (3) Not Applicable (2)

SRM - Downscale (2) (3) Startup or Control Shutdown (2)

IRM - Detector Not in Startup Position (2) (3) Not Applicable (2)

Scram Discharge Instrument Volume Once/3 Months Refuel Not Applicable Hater Level-High Scram Discharge Instrument Once/3 Months Not Applicable Not Applicable Volume-Scram Trip Bypassed Recirculation Flow Converter Not Applicable Once/ Cycle Once/ Day Recirculation Flow Converter-Upscale Once/3 Months Once/3 Months Once/ Day Recirculation Flow Converter-Inoperative Once/3 Months Not Applicable Once/ Day Recirculation Flow Converter-Comparator Once/3 Months Once/3 Months Once/ Day Off Limits Recirculation Flow Process Instruments Not Applicable Once/ Cycle Once/ Day Logic System Functional Test (4) (6)

System Logic Check once/6 Months 63

NOTES FOR TABLES 4.2.A THROUGH 4.2.G

1. Initially once per month until exposure hours (M as defined on Figure 4.1.1) is 2.0 x 10 ; 5thereafter, according to Figure 4.1.1 with an interval not less than one month nor more than three months.
2. Functional tests, calibrations and instrument checks are not required when these instruments are not required to be operable or are tripped.

Functional tests shall be performed before each startup with a required frequency not to exceed once per week. Calibrations of IRMs and SRMs shall be performed during each startup or during controlled shutdowns with a required frequency not to exceed once per week. Instrument checks shall be performed at least once per day during those periods when the instruments are required to be operable.

3. This instrumentaticri is excepted from the functional test definition.

The functional test will consist of injecting a simulated electrical signal into the measurement channel.

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4. Simulated automatic attuation shall be performed once each operating cycle. Where possible, all logic system functional tests will be performed using the test jacks.
5. Reactor low water level, high drywell pressure and high radiation main steam line tunnel are not included on Table 4.2.A since they are tested on Table 4.1.2.
6. The logic system functional tests shall include a calibration of time delay relays and timers necessary for proper functioning of the trip systems.
7. Calibration of analog trip units will be performed concurrent with functional testing. The functional test will consist of injecting a simulated electrical signal into the measurement channel. Calibration of associated analog transmitters will be performed each refueling outage.

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3.2 BASES (Cont'd)

The control rod block functions are provided to prevent excessive control rod withdrawal so that MCPR does not decrease to the Safety Limit MCPR. The trip logic for this function is 1 out of n: e.g., any trip on one of six APRM's, eight IRM's, or four SRM's will result in a rod block.

The minimum instrument channel requirements assure sufficient instrumentation to assure the single failure criteria is met. The minimum instrument channel requirements for the RBM may be reduced by one for maintenance, testing, or calibration. This time period is only

31. of the operating time in a month and does not significantly increase the risk of preventing an inadvertent control rod withdrawal.

The APRM rod block function is flow biased and prevents a significant reduction in MCPR, especially during operation at reduced flow. The  ;

APRM provides gross core protection; 1.e., limits the gross core power increase from withdrawal of control rods in the normal withdrawal sequence. The trips are set so that MCPR is maintained greater than the Safety Limit MCPR.

The RBM rod block function provides local protection of the ccre, for a single rod withdrawal error from a limiting control rod pattern.

l The IRM rod block function provides local as well as gross core protection. The scaling arrangement is such that trip setting is less than a factor of 10 above the indicated level.

l A downscale indication on an APRM or IRM is an indication the instrument has failed or the instrument is not sensitive enough. In either case l

the instrument will not respond to changes in control rod motion and j thus, control rod motion is prevented. The downscale trips are as shown L in Table 3.2.C-2. l The flow comparator and scram discharge volume high level components have only one logic channel and are not required for safety.

The refueling interlocks also operate one logic channel, and are required for safety only when the mode switch is in the refueling position.

1 For effective emergency core cooling for small pipe breaks, the HPCI system must function since reactor pressure does not decrease rapidly enough to allow either core spray or LPCI to operate in time. The automatic pressure relief function is provided as a backup to the 71

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