ML20010C772
| ML20010C772 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 03/31/1981 |
| From: | ABB COMBUSTION ENGINEERING NUCLEAR FUEL (FORMERLY |
| To: | |
| Shared Package | |
| ML13308B934 | List: |
| References | |
| CEN-148(S)-NP, NUDOCS 8108200402 | |
| Download: ML20010C772 (65) | |
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.iAN ONOFRE UNITS 2 AND 3
. 00CKETS 50-361 AND.50-362 ,,
E CEN-148(S)-NP FUNCTIONAL DESIGN SPECIFICATION
. r FOR A ;
CONTROL ELEMENT ASSEISLY CALCULATOR O
RESPONSE TO NRC QUESTI0'iS -
221.18 A*iD 221.20 MARCH 1981 s
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C0!BUSTION EriGItiEERING. INC.
NUCLEAR PO'.,'ER SYSTEMS P0ilER SYSTEMS GROUP HIllD50 , CO:ifiECTICUT 06095 l
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LEGAL .*10TICE l
This response was prepared as an account of work sponsored by Combustion Engineering, Inc. fleither Combustion Engineering nor any person acting on its behalf: ;
f . a: Makes any warranty or representation, express or implied including the warranties of fitness for a particular purpose or cerchantability, with respect to the accuracy, completeness, or usefulness of the information contained in this response, or that the use of any information , apparatus, method, or process dis-closed in this response may not infringe privately owned rights; or
- b. Assumes any liabilities with respect to the
(~) use of, or for damages resulting from the use of, any information, appartus, method or process disclosed in this response.
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. 1 This document describes the San Onofre Units 2 and 3 CEAC ,
i functional design. Included in this design are changes to current ANO-2 Cycle 1 CEAC functional design. These f
changes are indicated by vertical bars iri the right margins.
The pages involved are 7,9,10,13 ,18,26,27,30-33,43,61.
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i Q ABSTRACT This document provides a description of the CEA Calculator (CEAC) and CEA Penalty Factor Algorithm functional design to be implemented in the DNBR/LPD ,
Calculator System of the Reactor Protection System. The scope of this functional description includes detailed specification of the CEAC Penalty Factor Algorithm, which is a component of the CPC/CEAC software.
Two CEACs are provided in the DNBR/LPD Calculator System. Each CEAC receives all of the CEA positions and ca'1culates two penalty factors based on the severity of CEA deviation within a subgroup. These two penalty factors are
- t transmitted to the CPCs to be included in the DNSR and LPD calculations.
Detailed algorithm descriptions are provided. The algorithm equations are written in symbolic algebra. All variables are defined, and units are specified where applicable. In add. tion, the 16-bit output buffer, which transmits the penalty factors to the CPCs, is defined. ,
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TABLE OF CONTENTS Page No._
Section No. Title
.2 LIST OF REVISIONS 3
AB'STRACT 4
TABLE OF CONTENTS
- 6 LIST OF FIGURES AND TABLES 7
LIST OF ACRONYMS AND DEFINITIONS
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8 1.0 ' INTRODUCTION .
8 1.1 PURPOSE 8
1.2 SCOPE .
9 1.3 APPLICABILITY 9
1.4 REQUIRED REFERENCES 1.5 -
APPLICABLECPCSOFTWARECHANGER5 QUESTS (SCR)FORTHIS ,
9 REVISION 10 .
g 2.0 CEAC, DESIGN BASIS '
U 'SPECIFIED FUEL DESIGN LIMITS 10 2.1 10 2.2 ANTICIPATED GPERATIONAL OCCURRENCES (A00's) 12 3.0 FUNCTIONAL DESIGN AND. COMPUTER DESIGN REQUIREMENTS 3.1 CEA CALCULATOR PENALTY FACTOR ALGORITHM FUNCTIONAL 12 REQUIREMENT 3.1.1 REQUIREMENTS FOR ACCOMMODATION OF DEFINED SINGLE CEA-RELATED A00's 13 13 3.1.2 INPUTS AND OUTPUTS 15 3.2 PROGRAM STRUCTURE 18 3.3 PROGRA1 TIMING AND INPUT SAMPLING RATES 19 3.4 PROGRAM INTERFACES 20 3.4.1 CEAC FAILURE FLAG 21 3.4.2 CASE 2 DEVIATION FLAG 21 3.4.0 SCALING FLAG ,
22 3.4.4 CEAC OFF-LINE STORAGE AND RELOADING 22 3.5 OPERATOR INTERFACE 23 3.5.1 ALARMS AND ANNUNCIATORS l 23 3.5.2 DISPLAYS AND INDICATORS 27 l 3.5.3 OPERATOR INPUT CEAC Func. Design Spec. Page 4 of 63 i
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\- Section No. Title Page No.
3.6 INITIALIZATION 27 3.7 TESTING REQUIREMENTS 27 4.0 ALGORITHM DESCRIPTION 29 4.1 PENALTY FACTOR ALGORITHM .30 4.1.1 ALGORITHM INPUT 30 4.1.2 DETERMINATION OF DEVIATION 37 4.1.3 DETERMINATION OF PENALTY FACTORS 47 4.1.4 PACKING OF PENALTY FACTORS FOR TRANSMITTAL TO CPCs 57 4.1.5 CEAC INITIALIZATION 60 4.1.6 CEAC CONSTANTS 61
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() LIST OF TABLES Table No. Title _Page No.
3-1 CEAC OUTPUT SIGNALS 16 3-2 EXAMPLE OF FAILED SENSOR ARRAYS 25 4-1 ASSIGNMENT OF CEDMs TO SUSGROUPS FOR ANO-2 31 4-2 ASSIGNMENTS OF SUBGROUPS TO CONTROL GROUPS FOR ANO-2 FIRST FUEL CYCLE 32 LIST OF FIGURES ,
Figure No. Title- Page No.
3-1 CEA CALCULATOR INPUT INTERFACE DIAGRAM FOR ANO-2 14 4-1 PENALTY FACTOR COMPONENTS .
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() LIST OF ACRONYMS AND DEFINITIONS Name Definition Ah;-2 ARKANSAS NUCLEAR ONE - UNIT 2 A00 ANTICIPATED OPERATIONAL OCCURRENCE CEA CONTROL ELEMENT ASSEMBLY CEAC CONTROL ELEMENT ASSEMBLY CALCULATOR CEDM CONTROL ELEMENT DRIVE MECHANISM '
CPC CORE PROTECTION CALCULATOR CRT CATHODE RAY TUBE DISPLAY UNIT ,
DNBR DEPARTURE FROM NUCLEATE BOILING RATIO LPD LOCAL POWER DENSITY SONGS-2,3 SAN ONOFRE NUCLEAR GENERATING STATION.- UNITS 2, 3 LP&L-3 LOUISIANA POWER AND LIGHT - UNIT 3 (WATERFORD - 3)
MAX (---) MAXIMUM VALUE OF THE FOLLOWING .
MINIMUM VALUE OF THE FOLLOWING MIN (---)
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() RSPT SAFDL REED SWITCH POSITION TRANSMITTER SPECIFIED ACCEPTABLE FUEL DESIGN LIMITS .
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. 1 Page 7 of 63 LEAC Func. Design Spec.
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1.0 INTRODUCTION
1.1 PURPOSE The purpose of this document is
- 1. To specify a CEA Calculator (CEAC) functional design and functional interface that meet the design bases given in Section 2.0, when implemented with quality assured data constants,
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- 2. To serve as a quality assured interface document between the C-E engineering groups responsible for specification of the CEAC functional design and those responsible for implementation' of the CEAC design for the C-E NSSS identified in Section 1.3, and, .
O 3. To provide e quelity essured record of the cec design for reference by C-E design groups that are not directly respon- ..
'. sible for the CEAC design, but require knowledge of the design specification for related tasks. .
i 1.2 SCOPE This functional description provides the following:
- 1. The CEA Penalty Factor Algorithm to be' implemented in the DNBR/LPD Calculator System of the Reactor Protection System
- 2. Algorithms to initiate alarms for CEA sensor failure and CEA deviation
. 3. A diagnostic failed sensor data stack i l
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- 4. Requirements on CEAC/CPC interfaces, system interfaces, and i system initialization. _ ,_
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I I 1.3 APPLICABILITY
- , This document is a generic description of the CEAC functional ,
design. It is considered to b2 applicable to the ANO-2, SONGS-2,
, and SONGS-3. - .
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2.0 CEAC DESIGN BASIS l .
1' The function of the CEAC is to scan all CEA positions and, based on any single-CEA deviation detected within a CEA subgroup, to calculate the single CEA position related penalty factors necessary to ensure that the CPCs calculate conservative approximations to .
the actual core peak Local Power Density (LPD) and Departure from Nucleate Boiling Ratio (DNBR) during single CEA-related Anticipated Operational Occurrences (A00s). ,
2.1 SPECIFIED FUEL DESIGN LIMITS The fuel design limits used to define the low DNBR and LPD trip settings to ensure the following Specified Acceptable Fuel Design Limits (SAFDLs) are not exceeded are: *
- a. The DNBR in the limiting coolant channd in the care shall not be 1.ess than the ratio where there is at least a 95% probability, with 95% cerfidence, that DNB is avoided.
- b. The peak LPD in the limiting fuel pin in the core shall not te greater than that value corresponding to the minimum temperature which would ini.iate i centerline fuel molting.
2.2 ANTICIPATED OPERATIONAL OCCURRENCES (A00s) i Anticipated ope,ational cecurrences are defined in Appendix A of l'
' 10CFR50 (General Design Criteria for Nuclear Power Plants) as:
" . . . thera conditions of normal operation which are expected to occur on: or more times during the life of the nuclear power unit . . ."
f The A00s accommodated by the CPCs using the CEAC generated penalty O factors are the foiiewins:
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- . _ , _ _ _CEAC Func. Design Spec., . _ . . . _
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- a. The insertion or withdrawal of a single full-length or part-length CEA including:
- 1. Uncontrolled insertion or withdrawal of a single CEA;
- 2. A single dropped full or part-length CEA;
- 4. A statically misaligned full or part-length CEA.
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O 3.0 FUNCTIONAL DESIGN AND COMPUTER DESIGN REQUIREMENTS 3.1 CEA CALCULATOR PENALTY FACTOR ALGORITHM FUNCTIONAL REQUIREMENT The CPC determination of the planar radial peaking factors at any given axial node is done by a table look-up routine,-
This table look-up routine utilizes a precalculated table of values for the planar radial peaking factor associated with those CEA groups that are inserted or withdrawn in a normal sequence into the axial node of interest. The normal sequence of group insertion or withdrawal is the prescribed plant techr.ical specification sequence.
To account for the increased radial peaking that would result from conditions other than normal, CEA position-related penalty factors are then applied. These nenalty factors are multiplicative factors applied to the look-up value to increase the planar radials for the effects of CEA groups being inserted or withdrawn out of ncrmal sequence and for excessive misalignment of subgroups from the -
group position. The penalty factors associated with the CEA ,
group and subgroup ACOs are calculated within the CPCs. The CEA Calculator (CEAC) accon.modates the tingle CEA deviation related A00s.
The single CEA deviation-related penalty factors calculated by the CEAC will accommodate changes in the local power density (LPD) and DNBR. The DNBR and LPD penalty factors calculated in the CEACs acconmodate changes in the core axial and radial shapes and the core power r.ot perceived in the CPCs during single CEA deviation events. !
1 The single CEA position-related penalty factors calculated by the CEAC must be such that a conservative approximation to the peak local power density and minimum DNBR is obtained in the CPCs during individual CEA-related A00s. Te satisfy this requirement the following specific functional. requirements, as a i minimum, must be satisfied.
_ CEAC Func. Design Spec. - Page"12 of 63
Requirements for Accommodation of Defined Sinole CEA-Related A00s
{;3.1.1 The CEA Penalty Factors generated by the CEAC for use in the CPC trip functions must be designed to accommodate the individual CEA-related A00s described in Section 2.2.
The bases for this requirement are: .
- 1. Criteria 25 and 29 of 10CFR50 Appendix A, " General Design Criteria for Nuclear Power Plants."
- 2. Regulatory Guide 1.70 ..
3.1.2 Inputs and Outputs The CEACs shall each receive analog core axial CEA position ,
measurenent signals which originate from one of two Reed Switch Each CEA Position Transmitters (RSPTs) associated with each CEA.
O position is meesered by two reeuneent ineepeneent RSeTs whicn-transmit analog signals to two redundant independent CEACs (refer to Figure 3-1 for ANO-2). The resoir~. ion requirements on the CEAC measurement of CEA position shall be such that (excluding process signal error) CEA position shall be determined to within The RSPT consists of a series of magnetically actuated reed switches spaced at intervals along the RSPT assembly and wired with precision resiaors in a voltage divider network. The RSPT is afHxed adjacent to the Control Element Drive Mechanism (CEDM) pressure housing and CEA extension shaft. A magnet attached to the CEA extension shaft actuates the adjacent reed switches, causing a voltage signal proportional to the CEA position to be .
transmitted for each CEA. The two RSPTs are isolated both electri-
. cally and physically from each other. The CEAC input signal derived from the RSPT output has a range of 5 to 10 volts corre-sponding tc 0 to 150 inches of CEA travel, or 0% to 100% withdrawal.
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FIGURE 3-1 g*) CEA CALCULATOR IllPUT I?;TER-
) V FACE DIAGRAtl FOR ANO-2
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The CEAC shall calculate tha CEA Penalty Factors based on CEA position sensor input data obtainec', from each of the RSPTs (refer to Figure 3-1 for ANO-2 Cycle 1). The components of the CEA Penalty Factors are determined froa the following data;
'l. A static penalty factor component calculated as a function of deviation magnitude within.a subgroup;
- 2. A dynamic Xenon penalty factor component calculated as a function of elapsed time during which excess deviation exists in the subgroup.
- 3. A correctio:, constant for the Xenon component.
The output signals for each CEAC are listed in Table 3-1.
O. The two contact outputs must ectuete operator eierms. The five digital-word outputs form the 16-bit output buffer shich transmits the CEA penalty factors to the CPCs. The CEAC Failure Flag indicates the quantity of failed sensors or the quantity of deviating CEAs per core quadrant excced limiting pre-set numbers.
Actuation of the CEAC. Failure Flag is described in mere detail in Section 3.4.1. Tha Scale Flag indicates the range of the penalty factors, and is described in more detail in Section 3.4.3.
3.2 PROGRAM STRUCTURE The CEAC design bases require that the calculator be capable of detecting CEA deviation, calculating the CEA penalty factors, and indicating by alarm and indicator flag CEA deviation, CEAC failure.
-. and sensor out-of-range failures. In addition, the CEAC will provide diagnostic information on CEA sensor failures. Therefore, the CEAC Penalty Factor Algorithm shall calculate or detemine the following quantities: ,
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CEAC Func. Design Spec.
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C0!CUSTION ENGINEERING, INC.
PROPRIETARY INFOR!!ATION Table 3-1 CEAC Output Signals Sicnal Type Range j -
CEAC Failure Flag. Digital Word Packed DNB.R Pen'alty Factor Digital Word I (minus 1.0)
Multiple CEA Deviations Digital Word I in Subgroup Flag Packed LPD Penalty Factor Digital Word I (minus 1.0).
Scale Flag Digital Pord I Sensor out-of-range Contact Output Alarm CEA Deviation Alarm Contact Output .
-1. Part of 16-bit output buffer.
- 2. See Section 3.4.
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- 1. To calculate the deviation (difference in position) amongst the CEAs in each subgroup.
- 2. To recognize excessive CEA deviation within a subgroup, and to identify each occurrence as a single CEA withdrawal,
-single CEA insertion, or multiple CEA deviations within a subgroup. .
- 3. To calculate and/or,look up 2 penalty factor for LPD, and a penalty factor for DNBR based on the type of deviation event, the magnitude of the deviation, the CEA subgroup with the deviation, the CEA configuration, and the elapsed time since the start of the deviation. The LPD and CNBR. penalty factors shall be selected as the maximum of the LPD and DNBR penalty factors calculated for cach subgroup. The maximum penalty factors minus one will be transmitted to the CPCs as part of the output of the CEAC. .
O 4. To determine the status of the CEAC sensor fail alarm and the CEA deviation alarm.
- 5. To check some conditions under which CEAC (or upstream hardware) failure should be indicated to the CFCs.
- 6. To provide diagnostic information on CEh sensor failures, and on the causes of a CEAC penalty factor.
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- 7. To provide an indicator to the CPCs of the scale used in determining the penalty factors transmitted.
used for the display. <
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3.3 PROGRAM TI!4ING AND INPUT SAMPLING RATES The CEAC Penalty Factor Algorithm software is designed for the purposes of providing, for existing CEA configurations, an on-line real-tima determination of the single CEA deviation related DNBR and LPD penalty factors to be applied in the CPC determination of the hot pin heat flux distribution, the adjusted compensated core average power, and the local power density. The algorithm required for this purpose is time oriented, with a calculation scheduling rate and update period that is compatible with overall CEAC/CPC system response requirements. The execution period is the maximum
.- time in seconds from the time CEA RSPT se'nsors are scanned to the time the CEAC calculated outputs are updated with new information from that input scan and calculation. The calculations shall be scheduled in such a manner that the update requirements are met.
O. There ere two CEAC System uP d ete Periods: .
' Update Period
- 1. The The update period consists of a periodic fixed scheduling rate. The CEAC Fenalty Factor
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Program outputs shall be updated ,
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- 2. The Update Period
.This update consists of a fixed algorithm scheduling rate The CEAC Penalty Factor Program calculated output to a CRT bar graph .
display showing individual CEA positions arranged in subgroups and groups shall be updated .
-- . J The tolerance on the execution periods p _
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. e 3.4 PROGRAM INTERFACES ,
O G In addition, Communications with the CPCs must be rapid and simple.
the output to the CPCs must not change until after execution of the CEACs has been completed. This is accomplished by a 16-bit output buffer which transmits data to each CPC. This output buffer shall have a memory location, and the 16 bits shall be assigned in the following manner: --
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l 3.4.1 CEAC Failure Flag .
A CEAC failure flag shall be transmitted to the CPCs as part of the 16-bit output buffer. This flag shall be set true when either or both of the following conditions occur: .
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The CEAC Penalty Factor Program shall perform sensor out-of-range validity checks on the raw RSPT sensor input data and initiate a sensor-out-of-range alarm when out of range conditions are detected.
Analog signals outside the acceptable operating range represent failure of the RSPT. If this check indicates sensor in-range, a is then performed. If either of these checks fail, the sensor fail flag is set.
In addition, the CEAC failure flag should be set for internal processor faults including fixed point divide faults, floating point arithmetic fault, memory parity errors, illegal machine instruction, or failure to meet the timing requirements of
-) Section 3.3. .
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CEAC Func. Design-Spec.
P 3.4.2 Case 2 Deviation Flag
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A Case 2 deviation (or large penalty factor) flag shall be trans-mitted to the CPCs as part of the 16-bit output buffer. Tliis t
flag shall be set true when either or both of the following conditions occur:
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- l The CEAC Penalty Factor Program shall check for indications of
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- - - r 3.4.3 Scaling Flag After the DN8R and LPD penalty factors have been calculated, each penalty factor is prepared for packing into the 16-bit output ;
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.g 3.4.4 CEAC Off-Line Storage and Reloading To accommodate events where reloading of the CEAC Penalty Factor Algorithm program is required because of software and/or hardware failures, a means shall be provided to permit rapf'd reloading of
(]} the CEAC software from a suitable off-line mass storage device
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(one per CEAC). The off-line storage device shall be utilized for normal CEAC start-up loading but not during normal CEAC operation.
3.5 OPERATOR If1TERFACE The reactor operator shall be informed of the status of the CEACs by three mechanisms:
- 1. The calculators generate alarms to alert the operator to CEA sensor failure or excessive CEA deviation.
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n Qi 2. The CRT Video Monitor displays the position of the individual CEAs arranged into subgroups and control groups utilizing a bar graph representation, the floating point values of the two penalty factors, and a flag to indicate the cause of any alarms.
- 3. The CPC/CEAC operator's module provides CEAC inputs, selected intermediate variables, and outp;:ts.
3.5.1 Alarms and Annunciators A CEA deviation alarm (including Case 2 type deviations) and a failed sensor alarm shall be provided to the Plant Annunciator System (audible and visual) and to the CPC/CEAC operator's module.
Removal of the alarm indication should be prohi,bited unless the condition causing the alarm no longer exists. .
O- 3.5.2 Disolays and Indicators. ,
Both CEACs shall be linked to a single CRT Display Generator for ,
the purposes of displaying individual CEA position information.
The connection between the data link and each individual CEAC .
shall be made via,an appropriate isolation device (as defined in IEEE Std. 279-1971). A manual selection switch shall be utilized to determine which of the two CEACs the Display Generator will utilize in generating a CEA position display. The CEA Position Display (Figure 3-1) consists of a CRT Video Monitor and a Display Generator.
The CRT Video Monitor shall display the position of the individual CEAs arranged into subgroups by control groups utilizing a bar
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graph representation. The CEAs and subgroups assic.ed to each control group shall be recorded above the bar graphs. The CRT O
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,A shall provide an indication of CEA deviation wnich allows the
%) deviating CEAs to be identified as well as the magnitude of the deviation.
Provisions shall also be made to allow the operatnr to obtain a digital position read out in units of inches frena the bottom of the core by addressing the particular point I.D. of the CEA on the operator's module certain CEAC intermediate variables a'nd outputs (including the LPD and DNBR penalty factors and the packed penalty factor word to be transmitted to the CPCs) shall be available through the operator"s module.
Each CEAC shall provide diagnostic information to the operator via the operator's module or a teletype. The three types of diagnostic information to be provided are: ,
- l. Failed sensor stack. -
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- 2. A " snapshot" or listing of CEA positions, penalty factors, and time of occurrence of the deviation.
- 3. A flag indic-ting the cause of any alarm.
Each CEAC performs sensor input out-of-range checks '-
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Table 3-2 Examole of Failed Sensor Arrays _
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. , , _ _ . _ . , - , .-. . . , -. -- -- - - . . _ . . , _ - ..__ __ . - - - . - - - . _ - - - - - - - - - - - - - - - - - - - -~ -- - ---- - - .
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nodule or a teletype. The failed sensor stack should be saved through auto-restarts. .
A " snapshot" of CEA positions, penalty factors, and time of deviation occurrence is initiated by 1) a CEAC penalty factor greater than one, 2) the large PF flag, 3) a CEAC failure caused
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(d Changing the constant from 1 to O could be used
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to clear the buffer. This information can be retrieved through a' teletype. The CEAC snapshot should be saved through auto-restarts.
A CEAC fail indication is transmitted to the CPCs under the following conditions:
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.3. Initialization and in-test mode,
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- 5. CEAC memory unprotected.
3.5.3 Operator Input The operator must have the capability to change a limited set of program constants, called adc*essable constants, via the input / output device. Modification of addressable constants shall be permitted only when a manual interlock has been activated. In addition means shall be provided to prevent mo'dification of any constants not designated " addressable". The required addressable constants are limited to one constant for clearing the snapshot buffer (3.5.2) and one constant for rewriting the entire CRT display on command.
p 3.6 INITIALIZATION
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The CEACs must be capable of initializing to steady state operation.,
for any allowable plant operating condition. Initialization should be complete within 15 seconds of initial CEAC startup or of restart following a CEAC failure or in-test conditior. Until initialization of a CEAC is complete, the CEAC failure flag shall be set.
l Durirn initialization, the calculated penalty factors shall apprc . ihe steady state value from the conservative direction.
Initialization shall be considered to be complete after at least five executions of the CEAC initialization program have occurred.
3.7 TESTING REQUIREMENTS The CEAC shall be designed to perform periodic testing of the Q, CEAC Penalty Factor Program upon operator demand.
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l The bases for this requirement are:
- 1. IEEE Std. 338-1971, "IEEE Trial Use Criteria for the Periodic Testing of Nuclear Power Generating Station Protection Systems."
- 2. Criteria 21 and 22 of 10CFR50 Appendix A," General Design Criteria for Nuclear Power Plants."
- 3. ' Regulatory Guide 1.22, " Periodic Testing of Protection System Actuation Functions.*
The testing of the program shall be accomplished by disabling the input interface and simulating new inputs from a periodic testing data base. Selected outputs will then be checked against a '
corresponding expected value data base, and differences will be identified. During the time the CEAC is undergoing periodic
() testing a digital code shall be generated and transmitted to the CPCs to identify that the CEAC unit is in-test.
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,- 4.0 ALGORITHM DESCRIPTION U
This section includes detailed description of the functions to be performed by the CEAC Program. For the program described below, the sequence of computations required is described in sufficient detail to allow the software de:igner tc specify the coding of the protection program. .
The > 'nalty factor algorithm produces two penalty factors, one for DNBR and one for LPD. These penalty factors are found by taking the largest DNBR penalty factor and the largest LPD penalty factor calculated for any subgroup. The penalty factors on the subgroup level are formed by combining a static DNBR penalty factor component with a dynamic Xenon penalty factor component, and by combining a static LPD penalty factor component with a dynamic Xenon penalty factor component.
The static DNBR and static LPD penalty factor components are
({]) calculated as a function of ~
[, }Thedyna.icXenonpenaltyfactorcomponentiscalculated" m
as a function of -
CEA position signals are read in and processed to screen out
-- false signals, and the status of the sensor fail alarm is determined. -
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, u 4.1 PENALTY FACTOR ALGORITHM i
4.1.1 Algorithm Input The inputs to the algorithm are a set of live CEA position signals received from the reed switch position transmitters. Each signal is processed to screen out fa'1se signals, i.e. each signal is checked for out-of-range and a O
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TAB!.E 4-1 Assignrr.ent of CECMs to Subgroups for ANO-2**
Sub-Group No. CEDM No.
1 2,3,4,5 2
6,7,8,9 3
10, 11, 12, 13 -
4 14, 16, 18, 20 5 - 15, 17, 19, 21 6
22, 23, 24, 25 7- 26, 27, 28, 29 8 30, 32, 34, 36 9
31, 33, 35, 37
-10 38, 40, 42, 44 11 39, 41, 43, 45 12 46, 47, 48, 49 13
- 50, 52, 54, 56 14 51, 53, 55, 57 58, 59. so. si O is 16 62,- 64, 66, 68 63, 65, 67, 69 17 18 70, 73, 76, 79 19
' 71, 74, 77, 80 20 -72, 75, 78, 81
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- 1. *CEDM No. 1 is to be capable of being assigned to any one of the 20 subgroups.
- 2. The assignment of CEDMs to subgroups as controlled by the CEDMCS is fixed for the life of the plant (except for CEDM #1)
- ** This CEDM assignment will differ for other plants.
O Page 31 of 63 CEAC func. Design Spec. _ _
TABLE 4-2 Assignments of Subgroups to Control Groups for ANO-2 First Fuel Cycle **
ASSIGNMENT OF SUBGROUPS TO CONTROL GROUPS CONTROL GROUPS * (Subgroup No.)
Regulating Group #6 12 Regulating Group #5 15 Regulating Group #4 3 Regulating Group #3 16, 17 Regulating Group #2 2, 19 .
Regulating Group #1 10, 11 Shutdown Group A 13, 14, 18, 20 .
Shutdown Group B 1,4,5,8,9
.() Part-Length Group P1 6 P2 7 Notes:
- Regulating Control Group #6 is the first to be inserted in-sequence and Group #1 is the last. Regulating Control Group #1 is the first to be withdrawn in-sequence and Group #6 is the last. The insertion /
i withdrawal sequence maintains 40% overlap of adjacent groups. ,
- This subgroup assignment will vary according to plant and fuel cycle.
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CEAC func. Design Spec. Page 32 of 63
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. . _ . . _.-.y_ . ._ _ .___ __.-_ _, 7___ _ , _ , __. _. m., y _.-_.
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_ . . _ . _ _ _ _ _ . _ . _ . - . _ . . _ _ _ _ _ _ . . . - - . .__ . -- ._ __ _ -. _ _ _ _ . _ - . . _ _ . . _ .. _-._._ _ _ _ .___ _ _ . ,_ . _ _ - _ _ . ~ . . - _ _ _
t -
if DEV >S g,g.,
O and if (BOT-DUP) < SX and if (DDN-TO N) < SX ,
then set the CEA deviation alarm.
Otherwise, the CEA deviation alarm is not set. The variables used in this section are O .
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. _ .- _.- - . _- .. _.. . .-. --.. - = ... .. .
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y , ..w- e .--- . ,c-r- -- + ,3- , ,-- -- --,. - _ , ---- __ , e -,-,-r-T -- , -.--,,y,.--
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- . . . . . - . - . . .s 4.1.3 Determination of Penalty Factors 4
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1 Page 49 of 63 ;
CEAC Func. Design Spec. :
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l l
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. - . . . . . . . . . . _. . . . _1 l _- - - - - .
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FIGURE 4-1:
O .
PENALTY FACTOR COMPONENTS
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w - -- i, ,,
~.. - . . . . _ = . . . . . . . . . - -
O O
The .LPD and DNBR penalty factors for each subgroup are determined _
by combining the static penalty factor component, the Xenon penalty factor component, and the appropriate Xenon correction constant. w i
O CEAC Func. Design Spec. Page 55 of 63 1
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l 4.1.4 Packina of Penalty Factors for Transmittal to CPCs O'"
The LPD and DNBR penalty factors are adjusted for packing into the penalty factor word. - .
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Page 57 of 63 CEAC func. Design Spec.
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4.1.5 CEAC Initialization M
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M CEAC func. Design Spec. Page 60 of 63
. - +
4.1.6 C6sc Constants The constants required for the CEAC are listed below. The following constants will be provided by the functional design group:
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. Page 63 of 63 CEAC func. Design Spec..
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ENCLOSURE 6 1
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