ML20045G778
| ML20045G778 | |
| Person / Time | |
|---|---|
| Site: | 05200001 |
| Issue date: | 06/28/1993 |
| From: | Fox J GENERAL ELECTRIC CO. |
| To: | Poslusny C Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 9307150170 | |
| Download: ML20045G778 (36) | |
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i GE Nuclear Eneryy GenealDeax Company 175 Curmer Awoue. San Juse. CA 95125 June 28,1993 Docket No. STN 52-001 Chet Poslusny, Senior Project Manager Standardization Project Directorate
. Associate Directorate for Advanced Reactors and License Renewal Office of the Nuclear Reactor Regulation
Subject:
Submittal Supporting Accelerated ABWR Schedule - Oscillation Power Range Monitor (OPRM) Deir Chet: Er. closed are SSAR markups responding to the NRC Staff request to provide an Oscillation Pawer Range Monitor (OPRM) for the ABWR. The design is the BWROG LPRM based OPRM (Option Ill applicable to ABWR). Please provide a copy of this transmittal to Jim Stewart. Sincerely, Y Jack Fox Advanced Reactor Programs cc: Fred Chao (GE) Alan Beard (GE) Norman Fletcher (DOE) I l I i 130165 ! 1 Ji93 211 i 9307150170 930628 PDR ADDCK 05200001 n M 3oEO A PDR ll l j li
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ABM ssasioo4, nev. n Standard Plant (a) signals to the APRM that are proportion- (c) A reference power level to the reactor recirculation system; and al to the local neutron flux at various
! locations within the rector core; (d) A simulated thermal power signal derived from each APRM channel which approxi-(b) signals to alarm high or low local neutron flux; and mates the dynamic effects of the fuel.
(c) signals proportional to the local neu- (c) A continuous LPRM/APRM display for de-tron flax to drive indicating meters and tection of any neutron flux oscillation ; auxiliary devices to be used for opera- in the reactor core. This includes the l tor evaluation of power distribution, flux oscillation detection,p-wwwated ! 4'4't/sam local heat flux, minimum critical power, and fuel burnup rate. in the APRM. 44 (f) A reference ponr it. vel to permit trip 7.1.2.61A Average Power Range Monitor (APRM) in response to a reactor internal pump j Subsystem trip. I 7.1.2.6.L5 Autoenated Traversing Incore Probe (1) Safety Design Bases (ATIP) Subsystems General Functional Requirements: (1) SafetyDesignBarcs The general functional requirements are that, under the worst permitted input LPRM None. The ATIP subsystem portion of the NMS bypass conditions, the APRM shall be capable is nonsafety reinted and is addressed in of generating a trip signal in response to Section 7.7 average neutron flux increases in time to prevent fuel damage The independence and (2) Nonsafety-RelatedDesignBases redunaancy inc orated into the design of {' The ATIP shall meet the following power the APRM shall be consistent with the generation design bases: N @g Igsafety design bases tion system. TheofRPS the design reactorbases protec-are (a) Provide a signal proportional to the Np 645 D discussed in Subsection 7.1.2.2. axial neutron flux distribution at the j .h7f Specific Regulatory Requirements: radial core locations of the LPRM detec-p p vpfl tors (this signal shall be of high pre. A;" ,A s ? M The specific regulatory requirements appli- cision to allow reliable calibration of 9,,%;pp for the neutron monitoring system are listed cable to the conttols and instrumentation LPRM gains) and vl e
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'a ' in Table 7.12. (b) Provide accurate indication of the axial position of the flux measurement to h,,getp;g 3 , allow pointwise or continuous measure-g p .i r*f (2) Nonsafety-Related Design Bases ment of the axial neutron flux distri-g j +"I" The APRM shall provide the following bution.
et " # ci functions: (c) Provide a totally automated mode of W IS 0 "' hs fu e-(a) A continuous indication of average operation by the computer-based reactor power (neutron flux) from a 1% automatic control system. IM
,,wk ( Ig ), to 125% of rated reactor power which shall overlap with the SRNM range. 7.1.2.LL6 Multi r%==8 Rod Block Monitor d (MREM) Subsystems
'T #' W f .[/III p (F Ph (b) Interlock signals for blocking further g rod withdrawal to avoid an unnecessary (1) SafetyDesignBasis y g h Q p f,* scram actuation; D l ( N np, f:t f"' f geI p-27 7.115 ; qt. W j y5Y c w&. V y4Y
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SS ' m1m imv. n - J.. Standard Plant -l Nong De MRBM subsystem portion of the NMS is non safety related and is addressed in Section 7.7. 1 (2) Non Safety-Related Design Basis The MRBM shall meet the following power generation design bases. ., (a) Provide a signal proportional to the average neutron flux level surrounding the control rod (s) being withdrawn and i (b) Issue a rod block signal if the prewet , setpoint is exceeded by this sigant which is propotional to the average neutron flux level sigani. , l 7.1.2.6.2 Process Radiation Moaltaetas Systens (1) Safety Design Bases General Functional Requirements: j l (a) Monitor the gross radiation level l j l 1
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M ' $3A6100Af7 nev n Standard Plant TABLE 7.1-1 1 COMPARISON OF GESSAR II i AND ABWR I&C SAFETY SYSTEMS (Continued) i I&C System GESSAR II Design . ABWR Design . RHR/ SHUTDOWN 2 shutdown cooling 3 shutdown cooling COOLING MODE: divisions with I suction divisions with 3 suction line. lines (1 per division). REMOTE SHUTDOWN RCIC controls available at RCIC controls replaced with SYSTEM (RSS): RSS panel HPCF controls at RSS panel. SAFETY RELATED Designed to address Designed to address ! DISPIAY Regulatory Guide 1.97, Regulatory Guide 1.97, INSTRUMENTATION: Revision 2. Revision 3. NEUTRON MONITORING Class 1E subsystems are Class 1E subsystems are IRM,LPRM & APRM. SRNM (combines IRM & SRM), SYSTEM (NMS): LPRM & APRM.g - - - . ~.: NEUTRON MONITORING Non-Class 1E subsystems are Non-Class 1E subsystenp are. SRM,TIP, and RBM ATIP, and MRB l SYSTEM (Continued) J', PROCESS RADIATION -- New system dermition and MONITORING SYSTEM organi7ation, i.e., new - instrument groupings, (PRMS): locations and ranges. DRYWELL VACUUM Electrically operated Mechanically operated RELIEF SYSTEM- butterfly valve. relief valve. CONTAINMENT (Not in GESSAR II scope) New system provided in ABWR ATMOSPHERE scope. MONITORING SYSTEM (CAMS): SUPPRESSION POOL 4 thermocouples in each of 4 thermocouples in each of 2 divisions at each of 6 : TEMPERATURE the 4 containment MONITORING quadrants. locations. SYSTEM: 4 X 4 - 16 total T/C's. 4 X 2 X 6 = 48 total T/C's. Added suppression pool level monitoring function. 7'I*D Amendtnent 27
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Standard Plant REV B (10) OperationalConsiderations Reactor core flow signals derived from core plate pressure drop signals are used in the The LPRM is a monitoring system with no APRM to provide the flow biasing for the special operating considerations. APRM rod block and thermal power trip set-point functions. There is also the Core ' 7.6.1.1.2.2 , Average Power Range Monitor Flow Rapid Coastdown Trip logic in the APRM s unit which utilizes the core flow and Nd.? #QQ,M*i'y[I Subsystem f -InstrumentationM, General Description
.hControls.t 4 (,,(orM[& hermal power information. T and ,
i also used to provide the flow (1) ) M, signal ,s (A[v) d % e g e fo- u Afe dd"' b biasing for the MRBM rod block setpoint <^ . 7'g The APRMs are safety-related systems. There are four divisions of DMC based APRM functions. (b) NX'N jgf channels located in the control room. Each / he APR liaRoiiditiisiing unir alsof channel receives 52 LPRM signals as inputs, i cludes an algorithm that p/ovides N- ! anc' averages such inputs to provide a core det ction of core oscillation resulted from average neutron flux that corresponds to the core 'n stability. This alg/rithm uses ccre average power. One APRM channel is LPRM ignals as input, andis based on'a a ssociated with each trip system of the ! specific tection method ogy that relates reactor protection system (RPS). However, the fuel f ermal res use in the fuel trip signal from each APRM division also assembly to e LPRM signals. It includes goes to all other RPS divisions, with proper a specific m ,tho of combining the ,
,7\ signal isolation. designated LPR signals in order to detect rs co) on.I W [L b ye b *, gfp) ' localized core pgwer ascillation. The l algorithm mo itorsscore power oscillation 4p\lb (2) ' Power Sources responses and provi s a trip signal if a
; APRM channels are powered as listed below: 4 growing'oscillatio with sufficient magnitide is detected. T COL applicant Channels will ' plement the oscilla 'on ' monitoring
; lo 'c function in the APRM i accordance ,
A 120 VAC UPS Bus A (Division I) l th the conclusion of the B Own e rs' - ) B 120 VAC UPS Bus B (Division II) wroup as recLuired_in Rubmeetinn 6.3. i C 120 VAC UPS Bus C (Division III) D 120 VAC UPS Bus D (Divisi f4) Trip Function 4 g) fop ess. 4 The trip units and LPRM channelgassociated APRM system tripsYare summarized in Table with each APRM channel receive power from 7.6 2. The APRM scram trip function is the same power supply as the APRM channel, discussed in Section 7.2. The APRM rod block trip function is discussed in Subsec-(3) Signal Conditioning tion 7.7.1.2. The APRM channels also pro-( O A/V M vide trip signals indicating when an APRM - APRM channel electronic equipment averages channel is upscale, downscale, bypassed, or the output signals from a selected set of LPRMs. The averaging circuit automatically inoperative. ~ [ corrects for the number of unbypassed LPRM (5) Bypasses and Interlocks ; Ygg.t g q amplifiers providing input signals. @) ArAr1 ! - One APRM channel may be bypassed at any Assignment of LPRMs to the APRM channels is time. The trip logic will in essence shown in Figure 7.6-1. The LPRM detector in become two-out- of-three instead of __ ; wo out of-four. # the bottom position of a detector assembly is designated Position A. Detectors above A @) Of A$ - { {gt }4fM ; are designated B and C, and the uppermost (6) Redundanc9 i ~ ~ detector is designated D. (a) g Fourindependent channels of the APRM moni-tor neutron flux. Any two of the four APRM channels which indicate an abnormal w .u m c2 a
MM Standard Plant 23A6100AF REv n
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condition will initiate a reactor scram via the RPS two out of four logic. The redundancy criteria are met so that in the g ' ~~ ~ 7 ) event of a single failure under permissible - ! APRM bypass conditions, a scram signal can - I A@f 7 p /.?.2 8 j l be generated in the RPS as required. #- \y ~ ~ ~ j (rn eggy, _ (7) Testability APRM channels are calibrated using data from previous full power runs and are test-ed by procedures in the instruction manual. Each APRM channel can be tested individually for the operability of the APRM scram and rod-blocking functions by introducing test s i g n a l s .g A self-Tbl,sbk b flI & h (jf( n tF{1 h e M-7.6-5.1 Amendment 29
F s Insert 7.6.1.1.2.2.A The OPRM is a functional subsysMm of the APRM. There are four safety related OPRM channels, with each OPRM channel as part of each of the four APRM channels. Each OPRM receives the identical LPRM signals from the corresponding APRM channel as inputs, and forms a special OPRM cell configuration to monitor the neutron flux behavior of all regions of the core. Each OPRM cell represents a combination of four LPRM signals selected from the LPRM strings at the four corners of a four-by-four fuel bundle square region. The OPRM detects thermal hydraulic instability and provides trip functions to the RPS to suppress neutron flux oscillation prior to the violation of safety thermal limits. The OPRM trips are combined with the . APRM trips of the same APRM channel, to be sent to the RPS. Insen 7.6.1.1.2.2.B The OPRM utilizes the same set of LPRM signals used by the APRM that this OPRM channel resides with. Assignment of LPRMs to the four OPRM channels is identical to that referred in Figure 7.6-1, which shows the assignment of LPRMs to APRM channels. Figure 7.6-1 A shows the detailed LPRM assignments to the four OPRM channels, including the assignment of LPRMs to the OPRM cells. With this configuration, each OPRM cell receives four LPRM inputs from four LPRM strings at the four comers of the 4X4 fuel bundle square. For locations near the periphery where one corner of the square does not include an LPRM string, the OPRM cells use the inputs from the remaining three LPRM strings. The overall axial and radial distribution of these LPRMs between the OPRM channels are uniform. Each OPRM cell has four LPRMs from all four different elevations in the core. LPRM signals may be input to more than one OPRM cell within an OPRM channel. The LPRM signals assigned to each cell are summed and averaged to provide an OPRM signal for this cell. The OPRM trip protection algorithm consists of trip logic depending on signal oscillation magnitude and signal oscillation period. For each cell, the peak to average value of the OPRM l signal is determined to evaluate the magnitude of oscillation and to be used in the setpoint , algorithm. The OPRM signal sampling and computation frequency is well above the expected l thermal-hydraulic oscillation frequency, essentially producing a continuous and simultaneous measurement of all defined OPRM cells. Insert 7.6.1.1.2.2.C For the OPRM trip function, the response signal of any one OPRM cell that satisfies the l conditions and criteria of the trip algorithm will cause a trip of the associated OPRM channel. Figure 7.6-2A illustrates the trip algorithm logic. The OPRM trip function does not have its own inoperative trip for insufficient number of total LPRM inputs in the channel. It follows the APRM's inoperative trip of insufficient number of LPRMs. Insert 7.6.1.1.2.2.C.2 The APRM also sends an interlock signal to the SSLC similar to the SRNM "ATWS Permissive" signal (see Table 7.6-2). If this signal is a "high" level indicating the power is above the setpoint, this will allow the SSLC to pennit ATWS protection action. - __. - fL
Insert 7.6.1.1.2.2.D The OPRM channel bypass is controlled by the bypass or the APRM channel it resides with. Bypass of the APRM channel will bypass the OPRM trip function within this APRM channel. The OPRM also has its own separate automatic bypass functions: the OPRM trip output fmm i any cell is bypassed if: i) the APRM reading of the same channel is below 30% of rated power or the core flow reading is above 60% of rated flow; ii) the number of LPRM inputs to this OPRM cell is less than two. Any LPRM input to an OPRM cell is automatically bypassed if this LPRM reading is less than 5% of full scale LPRM reading. There is no requirement as to how many cells per OPRM channel has to be active since this is controlled by the total number of active LPRMs to the APRM channel. Insert 7.6.1.1.2.2.E There are four independent and redundant OPRM channels. The above APRM redundancy condition also applies to OPRM since each OPRM is a subsystem of each of the four APRM channels. The OPRM trip outputs also follows the two-out-of-four logic as the APRM since the OPRM trip output are combined with other APRM trip outputs in each APRM channel to provide the final trip outputs to the RPS. In addition, each LPRM string with four LPRM detectors provides one LPRM input to each of the four independent and redundant OPRM channels. This provides core regional monitoring by redundant OPRM channels. Insert 7.6.2.1.1 (2) It also includes a trip from the OPRM subsystem algorithm which will issue a trip if the OPRM algorithm detects a growing neutron flux oscillation indicating core thermal hydraulic instability. . l l 1
, . b ABM zwuw netf. B Standard Plant 7.6.2 ANALYSIS (2) Power range neutron monitors (PRNM) 7.6.2.1 Neutron Monitoring System - The PRNM subsystem provides information for instrumentation and Controls monitoring the average power level of the , reactor core and for monitoring the local The analysis for the trip inputs from the neu. power level when the reactor power is in the tron monitoring system (NMS) to the reactor pro- power range (above approximately 15% tection (trip) system (RPS) are discussed in power). It mainly consists of the LPRM and l Subsection 7.2.2. the APRM subsystems. The automatic traversing in. core probe (ATIP) (a) LPRM subsystem: The LPRM is designed to is a nonsafety related subsystem of the NMS and provide a sufficient number of LPRM is analyzed along with the other nonsafety sub- signals to the APRM system such that the systems in Section 7.7.2. safety design basis for the APRM is satisfied. The LPRM itself has no i This analysis section covers only the safety- safety design basis. However, it is I related subsystems of the neutron monitoring sys- qualified as a safety related system. tem (NMS). These include the following: (b) APRM subsystem: The APRM is capable of (1) Startup range neutron monitor subsystem generating a trip signal to scram the reactor in response to excessive and (SRNM) unacceptable neutron flux increase, in (2) Power range neutron monitor subsystem (PRNM) time to preveat fuct damage. Such a which includes: trip signal also includes a trip from ! the simulated thermal power signal which (a) Local power range monitor subsystem is a properly delayed signal from the j (LPRM), and APRM signal. It also includes a trip l from a core flow based algorithim which I (b) Average power range monitor subsystem will issue a trip if the core flow l suddenly decreases too fast, called the i (APRM) 7.6.2.1.1 General Functional Requirements Core Flow Rapid Coastdown trip. scram function is assured so long as minimum LPRM input requirement to the 11 7l
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Conformance APRM is satisfied. If such an input m l (1) Startup range neutron monitors (SRNM) requirement cannot be met, a trip signal - shall also be generated. The indepen-The SRNM subsystem is designed as a safety- dence and redundancy requirements are related system that will generate a scram incorporated into the design and are trip signal to prevent fuel damage in the consistent with the safety design basis event of any abnormal reactivity insertion of the RPS. r transients while operating in the startup ' power range. This trip signal is generated 7.6.2.1.2 Specific Regulator.v Requirements by either an excessively high neutron flux Conformana level, or too fast a neutron flux increase i rate, i.e., reactor period. The setpoints of Table 7.10. identifies the neutron monitoring ! these trips are such that under worst reac- system (NMS) and the associated codes and stan- i tivity insertion transients, fuel integrity dards applied in accordance with the Standard is always protected. The independence and Review Plan. The following analysis lists the -l I redundancy requirements are incorporated into applicable criteria in order of the listing on the design of the SRNM and are consistent the table, and discusses the degree of confor-with the safety design bases of the reactor mance for each. Any exceptions or clarifica-protection system (RPS). tions are so noted. l l 7.6 12 Amendment 27
, s ABM 23xsimse i Standard Plant REV.B l 1
(1) 10CFR50.55a (IEEE 279): as applicable. The GDCs are generi- l cally addressed in Subsection 3.1.2. ) The safety-related subsystems of the neutron monitoring system consist of four divisions (3) Regulatory Guides (RGs): which correspond and interface with those of the reactor protection system (RPS). This in- In accordance with the Standard Review Plan j dependence and redundancy assure that no sin- for Section 7.6, and with Table 7.12, the gic failure will interfere with the system following RGs are addressed for the NMS: ! operation. l (a) RG 1.22 - Periodic Testing of Protec. l The 10 SRNM' channels are divided into four tion System Actuation Functions divisions and independently assigned to three bypass groups such that up to three SRNM (b) RG 1.47 Bypassed and Inoperable channels are allowed to be bypassed at any Status Indication for Nuclear Power time while still providing the required Plant Safety Systems monitoring and protection capability. (c) RG 1.53 - Application of the Single- l There are 52 LPRM assemblies evenly distri- Failure Criterion to Nuclear Power buted in the core. There are four LPRM de- Protection Systems tectors on each assembly, evenly distributed l from near the bottom of the fuel region to (d) RG 1.75 - Physical Independence of l near the top of the fuel region (Figure 7.6- Electric Systems 3). A total of 208 detectors are dividied and assigned to four divisions for the four (c) RG 1.97 - Instrumentation During and APRMs. Any single LPRM detector is only Following an Accident l I assigned to one APRM division. Electrical wiring and physical separation of the divi- (f) RG 1.105 - Instrument Serpoints for sion is optimized to satisfy the safety re- Safety Related Systems
- lated system requirement. With the four di-visions, redundancy criteria are met since a (g) RG 1.118 - Periodic Testing of Elec-scram sigaci can still be initiated with a tric Power and Protection Systems postulated single failure under allowed APRM -
6 Me~ ""# The NMS conforms with all the above-listed bypass
, . , moa conditions.[rrr.7h en ffsA #G wh+#<" F*d RGs assuming the same interpretat IAllErnfo$ents used for the safety related clarifications identified in Subsections functions are qualified for the environments 7.2.2.2.1(7), 7.3.2.1.2 and 7.1.2.10.
in which they are located (Sections 3.10 and 3.11). (4) Branch Technical Positions (BTPs): All applicable requirements of IEEE 279 are In accordance with the Standard Review Plan met with the NMS. for Section 7.6, and with Table 7.12, only BTPs 21 and 22 are considered applicable (2) General Design Criteria (GDC): for the NMS. They are addressed as follows: In accordance with the Standard Review Plan for Section 7.6, and with Table 7.12, the (a) BTP ICSB 21 - Guidance for Applica-following GDCs are addressed for the NMS: rion of Regulatory Guide I.47: L!Q ) The ABWR design is a single unit. Therefore, (a) QiktiA: GDCs 2,4,10,73,19, and 28.
- A item B-2 of the BTP is not applicable. Other-(b) Conformance: The NMS is in compliance wise, the NMS is in full compliance with this with these GDCs, in part, or as a whole, BTP.
7.6 13 Amendsune 27
o . 23A6100AF Standard Plant REV.B 'l
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TABLE 7.6-2 ; APRM TRIP FUNCTION
SUMMARY
i o) BPJ1 Ty ke+f- l Trio Function Trin Setnoint (Nominal) Action APRM Upscale Flux Trip 118% power Scram (onlyin RUN) i 13% power Scram (not in RUN) APRM Upscale Flux Alarm Flow biased Rod Block (onlyin RUN) 10% power Rod Block (not in RUN) l APRM Upscale Thermal Trip Flow biased Scram , APRM Inoperative LPRM input too few Scram & Rod Block Module interlocks disconnect Electronics Critical Failure
.bi APRM DowEeN 5%- m - ' Rod Block
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AfRd ATws Permssut i i To 3 ( AII He s ( N le 0 Core Flow Rapid Coastdown '-fixed (Noteg) / / Scram (Note l) (
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Core Flow Upscale Alarm 120% (flow) Rod Block (onlyin RUN) Notds: th (, AfCm hAs lo sed:u fe s four l< vel Ua J % Cd foo r 'n ov0!r 4* dr*ove PA~**-
- d. } The trip signal is based on a flow-dependent equation. If the flow decreases too
/ fast, the trip signal will reach the fixed trip setpoint and initiate scram. The thermal power signal is only used as a criteria to determine scram bypass condition.
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23A6100AF Standard Plant - %n Table 7.6-5 REACTOR OPERATOR INFORMATION FOR NMS (1) The NMS provides for the activations of the following annunciations at the main control panel, (a) SRNM neutron flux upscale reactor trip (b) SRNM neutron flux upscale rod block (c) SRNM neutron flux downscale rod block (d) SRNM short period reactor trip (e) SRNM short period rod block (f) SRNM inoperative reactor trip
-(g) SRNM period withdrawal permissive alarm (h) APRM neutron flux upscale reactor trip (i) APRM simulated thermal power reactor trip (j) APRM neutron flux upscale rod block (k) 'APRM neutron flux downscale rod block (1) Reference APRM downscale rod block (m) APRM system inoperative reactor trip (n) Core flow rapid coastdown reactor trip (o) APRM core flow upscale rod block (p) Core flowinoperative alarm (q) LPRM neutron flux upscale alarm (r) LPRM neutron flux downscale alarm '
(s) ATIP automatic control system (ACS) inoperative i (t) ATIP indexer inoperative (u) ATIP control function inoperative (v) ATIP valve control monitor function inoperative , (w) MRBM upscale rod block (x) MRBM downscale rod block (y)'MRBM inoperative rod block (z) dore flow abnormal (5.0 pfRt1 Trip (2)jThe NMS provides status information on the dedicated NMS operator interface on the main j control panel as follows: (a) APRM power level (b) Srnm power level (3) The dedicated operator interface of the NMS provides logic and operator controls, so that the operator can perform the following functions at the main control panel: (a) APRM channel bypass (b) SRNM channel bypass (c) MRBM main channelbypass (d) MRBM rod block logic test (e) MRBM upscale rod block setpoint setup to intermediate / normal 7.6-23.1 Amendmen 27
y 4 M 33A6100AF au s Standard Plant Table 7.6-5 REACTOR OPERATOR INFORMATION FOR NMS (Continued) (4) Certain NMS - related information, available on the main control panel,is implemented in software which is independent of the process computer. This information is listed below. (a) SRNM reactor period (b) SRNM count rate (c) APRM bypass status l (d) APRM neutron flux upscale trip / inoperative status (c) APRM neutron flux upscale rod block status (f) APRM neutron flux downscale rod block status (g) APRM core flow upscale rod block status (h) APRM core flow rapid coastdown status (i) APRM core flow rapid coastdown bypass status ' (j) MRBM main channel bypass status (k) MRBM main channel upscale rod block status I (1),MRBM main channel downscale rod block status (m) fdRBM main channelinoperative rod block status (n) MRBM main channel core flow abnormal rod block status (o) o rRM Try Abs 1 (5) CRT displays, which are part of the performance monitoring and control system, provide (Vfcertain NMS-related displays and controls on the main control panel which are i (a) SRNM upscale trip / inoperative status 1 (b) SRNM reactor period trip status (c) SRNM upscale rod block status (d) SRNM reactor period rod block status (c) SRNM downscale rod block status (f) SRNM bypa.s status (g) SRNM period historical record (h) SRNM count rate historical record (i) SRNM period-based permissive (j) LPRM string selected for status readings ' (k) LPRM neutron fluxlevel(Designated group of LPRMs displayed upon selection of certain single rod or gang of controlrods) (1) LPRM bypass status (m) LPRM neutron flux downscale alarm status (n) LPRM neutron flux upscale alarm status (o) Number bypassed LPRMs and APRM channel (p) APRM simulated thermal power reactor trip status (q) APRM core flow l (r) Core flow historical record l (s) APRM neutron flux (t) APRM simulated thermal power trip setpoint (u) APRM simulated thermal power l l (v) APRM simulated thermal power record j (w) Reference APRM downscale rod block status (One for each MRBM main channel) ; (x) MRBM main channelblock level status 1 (y) MRBM main channel upscale (normal) rod block setpoint (z) MRBM main channel upscale (intermediate) rod block setpoint l 1 I 1 74 23.2 l Amendment 27 I i L
4 23AM00AF . Standard Plant un Table 7.6-5 REACTOR OPERATOR INFORMATION FOR NMS (Continued) (aa) MRBM main channel upscale (low) rod block setpoint (ab) MRBM main channel upscale (normal) rod block setpoint historical record - (ac) MRBM main channel upscale (intermediate) rod block setpoint historical record (ad) MRBM main channel upscale (low) rod block setpoint historical record (ae) MRBM subchannelinoperative status (af) MRBM subchannel upscale rod block status , (ag) MRBM subchannel downscale rod block status (ah) MRBM subchannelintermediate level transfer rate (ai) MRBM subchannel normal level tramfer rate (aj) MRBM subchannel reading
#,e ~x (ak) MRBM subchannel reading historical record N N (al) MR BM subchannel setup permissive-(am) MRBM gain adjustment failed / E P ..st
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(an) No rod selected (MRBM) ., (ao) Peripheral rod selected (MRBM) (o ofge4 M I oc" Pva shk <, h o QPH " f'M , ACRONYMS { (arl opr1 Wp S4As / NMS - Neutron Monitoring System % SRNM - Startup Range Neutton Monitor (^5 ) . oI'd P" , APRM - Average Power Range Manitor / LPRM - LocalPower Range Monito'r x ATIP - Automatic Traversing In-Core Probe ' - MRBM - Multi-channel Rod Block Monitoi' CRT - Cathode RayTube 7.6 233 Amendment 27
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-lf St>=51 W St>= t- ) j t < = S(t I!,5 5
'I St - (t+dt) Etf m(tp2-tp1)sT!
-t t t at _ ,3 ","
Noninal Values of Parameters: S1 = 1.1 52 0.92 DR3 >= 1.3 Smax = 1.3 T1 = 0.31 set ,c , , lh - 2.2 see i no -- S3 = (P1 1.0) x DR3 +1.0 dt St
= 0.050 sec
= (Filtered Fluu) / (Time Averaged Flux)
)h if St>=S(t dt) ~
Set tp3=t '-If T1<(tp3-tp2)=S(t+dt)
(Filtered Fh2x : no high frequency norses, Time Averaged Flux: FItered w/ 6 sec twne constant) l no Period Based Detection Ak)orithm scan t I= sean t im to l no if Tmin<TO<Tmax
+ Set m -
seg N=0 )[tf St>=S(t-dt) yes Set - U If St<=S(t-dt) yes Set )[ if St>=S(t-dt) yes t t0=t 5 St>=S(t+dt) tp1 -t tp2-t
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& St<=S(t+dt) & St>=$(t+dt) #"
g T0=tp3-tp1 _, - l yes ff Tmin+te<TO<Tmax-te I. 1 l l 1 yes
-> Set N=N+1 If N>Np if St>=Sp 4 issue trip Nortunal Values of Parameters:
Trnin = 1.0 sec Tmax = 3.5 sec l* = te Np = 10
= 0.15 sec Sp = 1.1 dt = 0.050 see St = (Fitered Flux /
T)rne Averaged Flux) l Figure 7.6-2A OPRM Logic
, . 'S w ,__ GENucle:r En:rgy Generalbettnc Company 175 Curtner Avenue. San Jose. CA 95125 3 une 28,19')3 Docket No. STN 52-001 Chet Poslusny, Senior Project Manager Standardization Project Directorate Associate Directorate for Advanced Reactors and License Renewal Office of the Nuclear Reactor Regulation
Subject:
Submittal Supporting Accelerated ABWR Schedule - Oscillation Power Range Monitor (OPRM)
Dear Chet:
Enclosed are SSAR markups responding to the NRC Staff request to provide an Oscillation Power Range Monitor (OPRM) for the ABWR. The design is the BWROG LPRM based OPRM (Option III applicable to ABWR). Please provide a copy of this transmittal to Jim Stewart. Sincerely, Jack Fox Advanced Reactor Programs cc: Fred Chao (GE) Alan Beard (GE) Norman Fletcher (DOE) Fo 211
zi4sion e ABM nuv n Standard Plant (a) signals to the APRM that are proportion. (c) A reference power level to the reactor recirculation system; and al to the local neutron flux at various
! locations within the rector core; (d) A simulated thermal power signal derived from each APRM channel which approxi.
(b) signals to alarm high or low local mates the dynamic effects of the fuet neutron flux; and (c) signals proportional to the local neu- (c) A continuous LPRM/APRM display for de-tron flux to drive indicating meters and tection of any neutron flux oscillation auxiliary devices to be used for opera- in the reactor core. This includes the tot evaluation of power distribution, flux oscillation detectione.purated local heat flux, minimum critical power, in the APRM. q,,% skM /,raN and fuel burnup rate. (f) A reference power level to permit trip 7.1.2.6.1A Average Power Range Monitor (APRM) in response to a reactor internal pump Subsystem trip. 7.12 A1 A Automated Traversing Incore Probe (1) Safety Design Bases (ATIP) Subsystems General Functional Requirements: (1) Safety Design Bases The general functional requirements are None. The ATIP subsystem portion of the NMS that, under the worst permitted input LPRM bypass conditions, the APRM shall be capable is nonsafety related and is addressed in of generating a trip signal in response to Section 7.7 average neutron flux increases in time to prevent fuel damage The independence and (2) Nonsafety-Related Design Bases redunaancy inc orated into the design of (V The ATIP shall meet the following power the APRM shall be consistent with the generation design bases: N Y Igsafety design basesThe tion system. of RPS the reactor protee-design bases are discussed in Subsection 7.1.2.2. (a) Provide a signal proportional to the My ld** 5 axial neutron flux distribution at the
,,< 6 g. ' f *3 radial core locations of the LPRM detec-Specific Regulatory Requirements:
p ,'ff tors (this signal shall be of high pre.
,,, A Ls ?
M The specific regulatory requirements appli- cision to allow reliable calibration of -{",#g, p cable to the controls and instrumentation for the neutron monitoring system are listed LPRM gains) and 3, sd ja e rf ""f in Table 7.1-2. (b) Provide accurate indication of the axial position of the flux measurement to p;g, a (2) Nonaafety-Related Design Bases allow pointwise or continuous measure-g p ,.i r*f ment of the axial neutron flux distri-p.t +"(" bution. The APRM shall provide the following W' # functions: MhM0 "' u (a) A continuous indication of average (c) Provide a totally automated mode of operation by the computer based automatic control system. reactor power (neutron flux) from a 1% p,IIMp( <w. h Ig), to 125% of rated reactor power which shall overlap with the SRNM range. 71211.6 Multi rs...: Rod Block Moaltar d/p1 a (MRBM) Subsystesa
- ggge (b) Interlock signals for blocking further rod withdrawal to avoid an unnecessary (1) SafetyDesignBasis hphfgp,*
D l scram actuation; t M (A[e
- p. t , Jg Amendmens 27 7.1 15 t .
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' ABWR 2s46ione REV.B Standard Plant v
NonejThe MRBM subsystem portion of the NMS i: ::: safety related and is addressed in hetic: 7.7.
-(2) Non Safety-Related Design Basis
' The MRBM sh'all meet the following power generation design bases.
(a) Provide a signal proportional to the average neutron flus level surrounding the control rod (s) being withdrawn and (b) Issue a rod block signal if the preset setpoint is execeded by this sigant whieb is propotional to the average neutron flux level sigani. l 7.1.2.6.2 Process Radiatlos Monitoring Systema (1) Safety Design Bases General Functional Requirements: l l (a) Monitor the gross radiation level t i l l l 7.1 111 Amamensa 27 j
ABWR 23xsioose Rev.n Standard Plant TABLE 7.1 1 COMPARISON OF GESSAR II AND ABWR I&C SAFETY SYSTEMS (Continued) I&C System GESSAR 11 Design ABWR Des!gn 2 shutdown cooling 3 shutdown cooling RHR/ SHUTDOWN COOLING MODE: divisions with 1 suction divisions with 3 suction line. lines (1 per division). REMOTE SHUTDOWN RCIC controls available at RCIC controls replaced with RSS panel HPCF controls at RSS panel. SYSTEM (RSS): SAFETY RELATED Designed to address Designed to address DISPIAY Regulatory Guide 1.97, Regulatory Guide 1.97, INSTRUMENTATION: Revision 2. Revision 3. NEUTRON MONITORING Class 1E subsptems are Class 1E subsystems are IRM, LPRM & APRM. SRNM (combines IRM & SRM), SYSTEM (NMS): LPRM & APRM.,. - 5 NEUTRON MONITORING Non-Class 1E subsystems are Non-Class 1E$ubsystenp ar8 ' SRM, TIP, and RBM ATIP, and MREM l SYSTEM (Continued)
%.J PROCESS RADIATION New system defmition and MONITORING SYSTEM organization, i.e., new instrument groupings, (PRMS):
locations and ranges. DRYWELL VACUUM Electrically operated Mechanically operated RELIEF SYSTEM: butterfly valve. relief valve. CONTAINMENT (Not in GESSAR 11 scope) New system provided in ABWR ATMOSPHERE scope. MONITORING SYSTEM (CAMS): SUPPRESSION POOL 4 thermocouples in each of 4 thermocouples in each of TEMPERATURE the 4 containment 2 divisions at each of 6 MONITORING quadrants. locations. SYSTEM: 4 X 4 = 16 total T/Cs. 4 X 2 X 6 - 48 total T/Cs. Added suppression pool level monitoring funedon. 7.1-25 Amendment 27
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- X X X X X X X X X X X X X X X X X X X X X X X X X X X X R15UWausg r., " Spey X X X X X X X X X X X X X X X X X X X X RHR/Sw PooICocinu X X X S ny Oes Tresammt
- X X X X X X X X X X X X X X X X X X X X Emergmey Diesel S - ;-=t X X X X X X X X X X X X X X Resear Bldg.Cooteg Water X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X E .tial HVAC S 1 c--, X X X X X X X X X X X X X X X X X X X X HVAC hm.Cooline Wu X X X Hi Press. Niwoga M X X X X X X X X X X X X X X X X X X X X X X Alwrnase Rod lasernca X St=-A-y uqued Cd X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X RHR/" *-- Coolma Remose SW., S,_.. X X X lL. X X X X X X X X Safety - Releaed Disgdey X X X/1 1 X X X X X X X X X X X X X X X X N-. Monid..g S1 -- X X f M)C / X X X X X X X X X X X X k D' X X X X X X X X X X X X X X X X X X X P,w Red. " _ z --L.i X HP/LP S,u" W X X X X' X X X X X X X X X X X X X X X l X X X em Agnos.Manitor / X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Sm,s Pool Temp Man. X X X !
X X X Control Sy=-dNon-lE)
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ch.,. egulatory Requirements Applicability Matrix for I & C Systems Sysia+> g j
\ -
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . , _ _ _ _ _ . _ _ _ _ _ _ _ _ - _ _ _ _ _ =
ABM utaiootr Standard Plant nry B (10) Operational Considerations Reactor core flow signals derived from core plate pressure drop signals are used in the The LPRM is a monitoring system with no APRM to provide the flow biasing for the special operating considerations. APRM rod block and thermal power trip ser-point functions. There is also the Core 7.6.1.1.2.2 Aterage Power Range Monitor Flow Rapid Coastdown Trip logic in the APRM
*e unit which utilizes the core flow and Subsystem W Y'f#%'g,(7$/] Instrumentation and Controls g (,,Gre[ thermal power information. The core flow gO,,
' g,g )
(1) General Desenption V., signal is also used to provide the flow b'
'j a[v ) A % 4 9 fo w M, ft biasing for the MRBM rod block setpoint c ^
The APRMs are safety-related systems. There functions. g 7-7 are four divisions of DMC based APRM #1 &&/ channels located in the control room. Each he APR ifafcinditi~oling unir alsor N channel receives 52 LPRM signals as inputs, j 'i cludes an algorithm that p[ovides N i and averages such inputs to provide a core det ction of core oscillation respired from average neutron flux that corresponds to the ; core 'n-stability. This algo'rithm uses core average power. One APRM channel is LPRM ignals as input, andJs based on a associated with each trip system of the , specific ctection method ogy that relates reactor protection system (RPS). However, the fuel thermal res use in the fuel trip signal from each APRM division also ' assembly to the LPR?f signals. It includes goes to all other RPS divisions, with proper ' a s p e cific m'e t h e of combining the s
,rs signal isolation. designated LPR signals in order to detect tp (r) ou.mw/La kp b % g/g) ,
' localized core p\wer ascillation. The (2) Power Sources algorithm moditors core power oscillation Op\9 P responses and provi i a trip signal if a APRM channels are powered as listed below: j growing' oscillatio with sufficient magnitide is detected. T COL applicant Channels will)diplement the oscilla 'on monitoring
;1 ic function in the APRM i accordance A 120 VAC UPS Bus A (Division I) th the conclusion of the B% Owners' B 120 VAC UPS Bus B (Division 11) roup as reauired_in Subuctinn&3 C 120 VAC UPS Bus C (Division III) ,
D 120 VAC UPS Bus D (D isi g g4) Trip Function y $1 foft The trip units and LPRM channels 4 associated </s.4 APRM system tripsYare summarized in Table with each APRM channel receive power from 7.6 2. The APRM scram trip function is the same power supply as the APRM channel. discussed in Section 7.2. The APRM rod l block trip function is discussed in Subsec-(3) Signal Conditioning tion 7.7.1.2. The APRM channels also pro-(0 Aftn vide trip signals indicating when an APRM r 1 APRM channel electronie equipment averages channel is upscale, downscale, bypassed, or the output signals from a selected set of inoperative. g LPRMs. The averaging circuit automatically corrects for the number of unbypassed LPRM (5) Bypasses and Interlocks Mp.t e amplifiers providing input signals. M) Apet One APRM channel may be bypassed at any Assignment of LPRMs to the APRM channels is time. The trip logic will in essence shown in Figure 7.61. The LPRM detector in become two out- of-three instead of _ the bottom position of a detector assembly }wo out of four. -- is designated Position A. Detectors above A M M O/$ {gt h,l./11 ) are designated B and C, and the uppermost (6) Redundancy .
^ ~ l detector is designated D. p1 (G)
Four Af< in dependent channels of the APRM moni-tor neutron flux. Any two of the four APRM channels which indicate an abnormal Ameadmem 29 hg.t 16 U.U1C7. *
..- a m urn 33A6t00AF 6W '#As Statidard Plant - nrv n con-dition will initiate a reactor scram via the RPS two out of four logic. The ' icdundoney uitcria are met so that in the 7 event of a single failure under permissible
'b APRM bypass conditions, a scram signal can ',- 1/icAtd 7 b#' 'I' be generated in the RPS as required. __
(%cffrig. (7) Testability APRM channels are calibrated using data from presious full power runs and are test-ad by nrncedures in the instruction
- nual. Each APRM channel can be tested individually for the operability of the APRM scram and rod-blocking functions by introducing test signals.g A self.
Tl.,3Alekt D fd h
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7.63.1 Amendment 29
o . Insert 7.6.1.L2.2.A The OPRM is a functional subsystem of the APRM. There are four safety related OPRM channels, with each OPRM channel as part of each of the four APRM channels. Each OPRM receives the identical LPRM signals from the corresponding APRM channel as inputs, and forms a special OPRM cell configuration to monitor the neutron flux behavior of all regions of the core. Each OPRM cell represents a combination of four LPRM signals selected from the LPRM strings at the four corners of a four-by-four fuel bundle square region. The OPRM detects thermal hydraulic instability and provides trip functions to the RPS to suppress neutron flux oscillation prior to the violation of safety thermal limits. The OPRM trips are combined with the APRM trips of the same APRM channel, to be sent to the RPS. Insert 7.6.1.1.2.2.B The OPRM utilizes the same set of LPRM signals used by the APRM that this OPRM channel resides with. Assignment of LPRMs to the four OPRM channels is identical to that referred in Figure 7.6-1, which shows the assignment of LPRMs to APRM channels. Figure 7.6-1A shows the detailed LPRM assignments to the four OPRM channels, including the assignment of LPRMs to the OPRM cells. With this configuration, each OPRM cell receives four LPRM inputs from four LPRM strings at the four comers of the 4X4 fuel bundle square. For locations near the periphery where one comer of the square does not include an LPRM string, the OPRM cells use the inputs from the remaining three LPRM strings. The overall axial and radial distribution of these LPRMs between the OPRM channels are unifonn. Each OPRM cell has four LPRMs from all four different elevations in the core. LPRM signals may be input to more than one OPRM cell within an OPRM channel. The LPRM signals assigned to each cell are summed and averaged to provide an OPRM signal for this cell. The OPRM trip protection algorithm consists of trip logic depending on signal oscillation magnitude and signal oscillation period. For each cell, the peak to average value of the OPRM signal is determined to evaluate the magnitude of oscillation and to be used in the setpoint algorithm. The OPRM signal sampling and computation frequency is well above the expected thermal-hydraulic oscillation frequency, essentially producing a continuous and simultaneous measurement of all defined OPRM cells. Insert 7.6.1.1.2.2.C For the OPRM trip function, the response signal of any one OPRM cell that satisfies the conditions and criteria of the trip algorithm will cause a trip of the associated OPRM channel. Figure 7.6-2A illustrates the trip algorithm logic. The OPRM trip function does not have its own inoperative trip for insufficient number of total LPRM inputs in the channel. It follows the APRM's inoperative trip ofinsufficient number of LPRMs. Insert 7.6.1.1.2.2.C.2 The APRM also sends an interlock signal to the SSLC similar to the SRNM "ATWS Permissive" signal (see Table 7.6-2). If this signal is a "high" level indicating the power is above the setpoint, this will allow the SSLC to permit ATWS protection action. I
Insert 7.6.1.1.2.2.D A CPRM channel bypass is controlled by the bypass of the APRM channelit resides with. Bypass of the APRM channel will bypass the OPRM trip function within this APRM channel. The OPRM also has its own separate automatic bypass functions: the OPRM trip output from any cell is bypassed if: i) the APRM reading of the same channel is below 30% of rated power or the core flow reading is above 60% of rated flow; ii) the number of LPRM inputs to this OPRM cell is less than two. Any LPRM input to an OPRM cell is automatically bypassed if this LPRM reading is less than 5% of full scale LPRM reading. There is no requirement as to how many cells per OPRM channel has to be active since this is controlled by the total number of active LPKNih to tne APRM channel. Insert 7.6.1.1.2.2.E There are fourindependent and redundant OPRM channels. The above APRM redundancy condition also applies to OPRM since each OPRM is a subsystem of each of the four APRM channels. The OPRM trip outputs also follows the two-out-of-four logic as the APRM since the OPRM trip output are combined with other APRM trip outputs in each APRM channel to provide the final trip outputs to the RPS. In addition, each LPRM string with four LPRM detectors provides one LPRM input to each of the four independent and redundant OPRM channels. This provides core regional monitoring by redundant OPRM channels. Insert 7.6.2.1.1. (2) It also includes a trip from the OPRM subsystem algorithm which will issue a trip if the OPPJi algorithm detects a growing neutron flux oscillation indicating core thermal hydraulic instability. i l i l l l l 1 l l
m _ - _ _ _ . ._ .. . ._ _ _ _ _ _ . _ . _ __ . o . 23A6100AF Standard Plant REv. n 7.6.2 ANALYSIS (2) Power range neutron monitors (PRNM) 74.2.1 Neutron Mooltoring System . The PRNM subsystem provides information for Instammentatloa and Controls monitoring the average power level of the reactor core and for monitoring the local The analysis for the trip inputs from the neu. power level when the reactor power is in the tron monitoring system (NMS) to the reactor pro. power range (above approximately 15% tection (trip) system (RPS) are discussed in power). It mainly consists of the LPRM and Subsection 7.2.2. the APRM subsystems. The automatie traversing in. core probe (ATIP) (a) LPRM subsystem: The LPRM is designed to is a nonsafety related subsystem of the NMS and provide a sufficient number of LPRM is analyzed along with the other nonsafety sub. signals to the APRM system such that the systems in Section 7.7.2. safety design basis for the APRM is satisfied. The LPRM itself has no This analysis section covers only the safety. safety design basis. However, it is related subsystems of the neutron monitoring sys. qualified as a safety.related system. tem (NMS). These include the following: (b) APRM subsystem: The APRM is capable of (1) Startup range neutron monitor subsystem generating a trip signal to scram the - reactor in response to excessive and (SRNM) unacceptable neutron flux increase, in (2) Power range neutron monitor subsystem (PRNM) time to prevent fuel damage. Such a which includea: trip signal also includes a trip from the simulated thermal power signal which (a) Local power range monitor subsystem is a properly delayed signal from the > (LPRM), and APRM signal. It also includes a trip from a core flow based algorithim which (b) Average power range monitor subsystem will issue a trip if the core flow suddenly decreases too fast, called the (APRM) ' Core Flow Rapid Coastdown trip. 11 . 74.2.1.1 General Functional Requirements scram function is assured so long as Me$ ~ Conformance minimum LPRM input requirement to the 7 gy, f' APRM is satisfied. If such an input (2) (1) Startup range neutron monitors (SRNM) requirement cannot be met, a trip signal - shall also be geaerated. The indepen. The SRNM subsystem is designed as a safety. dence and redundancy requirements are related system that will generate a scram incorporated into the design and are trip signal to prevent fuel damage in the consistent with the safety design basis - event of any abnormal reactivity insertion of the RPS. transients while operating in the startup power range. This trip signal is generated 74.2.1.2 Specific Itagulatory Requirements by either an excessively high neutron flux Confor==== level, or too fast a neutron flux increase rate, i.e., reactor period. The setpoints of Table 7.12 identifies the neutron monitoring these trips are such that under worst reac. system (NMS) and the associated codes and stan. tivity insertion transients, fuel integrity dards applied in accordance with the Standard is always protected. The independence and Review Plan. The following adpis lists the redundancy requirements are incorporated into applicable criteria in order of the listing on the design of the SRNM and are consistent the table, and discusses the degree -af confor. with the safety design bases of the reactor mance for each. Any exceptions or clarifica. protection system (RPS), tions are so noted. 7.6-12 Amwedawn:27
- - -- - _ . - - - - - -- - - 0-
. 9 .
ABM 2246moxr arv. s Standard Plant (1) 10CFR50.55a(IEEE279): as applicable. The GDCs are generi-cally addressed in Subsection 3.1.2. T!.c safety-related subsystems of the neutron monitoring system consist of four divisions (3) RegulatoryGuides(RGs): which correspond and interface with those of the reactor protection system (RPS). This in. In accordance with the Standard Review Plan dependence and redundancy assure that no sin- for Section 7.6, and with Table 7.12, the gle failure will interfere with the system following RGs are addressed for the NMS: operation. (a) RG 1.22 - Periodic Testing of Protec. l The 10 SRNM channels are divided into four tion System Actuation Functions divisions and independently assigned to three bypass groups such that up to three SRNM (b) RG 1.47 - Bypassed and Inoperable channels are allowed to be bypassed at any Status Indication for Nucleur Power time while still providing the required Plant Safety Systems monitoring and protection capability. (c) RG L. 3 - App!! cation of the Single. There are 52 LPRM assemblics evenly distri- Failu.e Criterion to Nuclear Power buted in the core. There are four LPRM de- Protection Systems tectors on each assembly, evenly distributed from near the bottom of the fuel region to (d) RG 1.75 - Physical independence of near the top of the fuel region (Figure 7.6 Electric Systems 3). A total of 208 detectors are dividied and assigned to four divisions for the four (e) RG 1.97 - Instrumentation During and APRMs. Any single LPRM detector is only following an Accident assigned to one APRM division. Electrical wiring and physical separation of the divi. (f) RG 1.105 - Instrument Setpoints for sion is optimized to satisfy the safety re. Safety Related Systems lated system requirement. With the four di-visions, redundancy criteria are met since a (g) RG 1.118 - Periodic Testing of Elec-scram signal can still be initiated with a tric Power and Protection Systems postulated single failure under allowed APRM - d"* bypassa.z 74s [ "s t.4 conditions./rn A WwM M '* *5"P'""*4 The NMS conforms with all the above listed qn RGs assuming the same interpretations and IAl! 7j$p.konents rn used for the safety related clarifications identified in Subsections functions are qualified for the environments 7.2.2.2.1(7), 7.3.2.1.2 and 7.1.2.10. j in which they are located (Sections 3.10 and 3.11). (4) Branch Technical Positions (BTPs): All applicable requirements of IEEE 279 are In accordance with the Standard P wiew Plan met with the NMS. for Section 7.6, and with Table '/.12, only BTPs 21 and 22 are considered applicable (2) General Design Criteria (GDC): for the NMS. They are addressed as follows: In accordance with the Standard Review Plan for Section 7.6, and with Table 7.1-2, the (a) BTP ICSB 21 - Guidance for Applica. ) ^ following GDCs are addressed for the NMS: tion of Regulatory Guide 1.47: j (a) Cnteria GDCs 2,4,10, ,19, and 28. The ABWR design is a single unit. Therefore, item B 2 of the BTP is not applicable. Other-(b) Conformance: The NMS is in compliance wise, the NMS is in full compliance with this with these GDCs, in part, or as a whole, BTP. 7.6 13 Amendswet 27
, .. , 1 MN 23A6100AF REV,B f Standard Plant \
. . - - . . . "' l TABLE 7.6 2 l I
APRM TRIP FUNCTION
SUMMARY
e ) M r M T y 4 c+f - Trio Function Trin Setooint (Nominal) Action APRM Upscale Flux Trip 118% power Scram (onlyin RUN) 13% power Scram (not in RUN) APRM Upscale Mux Alarm Mow biased Rod Block (onlyin RUN) 10% power Rod Block (not in RUN) l APRM Upscale Thermal Trip Flow biased Scram APRM Inoperative LPRM input too few Scram & Rod Block Module interlocks disconnect Electronics Critical Failure s
\i APRM DowNe 5%- m , Rod Block AfRM ATws Perm,um 6 Yo h
/ (onlyin RUN)
AH MA s ( Nde 0 j Core Flow Rapid Coastdown " fixed (Noteg)
/ 1 Scram (Note l) , ( (bypassed wph thermal
# p %)
Core Flow Upscale Alarm 120% (flow) Rod Block (onlyin RUN) Note's- ' " "Yl4 4* d'* * **
- P
I, IfCH h*s lo 'd:csIe ^ foot < \ < v*I h'I"'J U '$*Y
- d. ' The trip signal is based on a flow-dependent equation. If the flow decreaser, too
/ fast, the trip signal will reach the fixed trip setpoint and initiate scram. The thermal power signal is only used as a criteria to determine scram bypass condition.
7.6 22 Amendment 27
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~
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'il : o at h 2.2 sec, 7;:o,gl 6 1.tr,,
( k 4WC S cu Dr.4 7 6 -2 A ) Ont (ca { {~ % du; 4 /w wh c typ<neA <r % fwu S 3 s 7. O'"db~ d+k Pk T'r e : C+{r pam(os tlJ N?
- c *l* ~
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Mb 23A6100AF new n 4 Standard Plant Table 7.6-5 REACTOR OPERATOR INFORMATION FOR NMS (1) The NMS provides for the activations of the following annunciations at the main control panel. (a) SRNM neutron flux upscale reactor trip (b) SRNM neutron flux upscale rod block (c) SRNM neutron flux downscale rod block (d) SRNM short period reactor trip (e) SRNM short period rod block (f) SRNM inoperative reactor trip (g) SRNM period withdrawal permissive alarm (h) APRM neutron flux upscale reactor trip (i) APRM simulated thermal power reactor trip (j) APRM neutron flux upscale rod block (k) APRM neutroa flux downscale rod block (1) Reference APRM downscale rod block (m) APRM system inoperative reactor trip (n) Core flow rapid coastdown reactor trip (o) APRM core flow upscale rod block (p) Core flow inoperative alarm (q) LPRM neutron flux upscale alarm (r) LPRM neutron flux downscale alarm (s) ATIP automatic control system (ACS) inoperative (t) ATIP indexer inoperative (u) ATIP control function inoperative (v) ATIP valve control monitor function inoperative (w) MRBM upscale rod block (x) MRBM downscale rod block (y)~MRBM inoperative rod block (z) Dore flow abnormal (60 ofRt1 Top (2)pThe NMS provides status information on the dedicated NMS operator interface y control panel as follows: (a) APRM power level (b) Srnm power icvel (3) The dedicated operator interface of the NMS provides logic and operator controls, so that the operator can perform the following functions at the main control panet: (a) APRM channelbypass j (b) SRNM channelbypass I (c) MRBM main channel bypass (d) MRBM rod block logic test (e) MRBM upscale rod block setpoint setup to intermediate / normal i 74231 Amendment 27 l l
~ .
l 23A6100AF l ner n Standard Plant Table 7.6-5 i REACTOR OPERATOR INFORMATION FOR NMS (Continued) i (4) Certain NMS - related information, available on the main control panel,is implemented in software which is independent of the process computer. This information is listed below. (a) SRNM rea; tor period (b) SRNM count rate (c) APRM bypass status (d) APRM reutron flux upscale trip / inoperative status (c) APRM neutron flux upscale rod block status (f) APRM neutron flux downscale rod block status (g) APRM core flow upscale rod block status (b) APRM core flow rapid coastdown status (i) APRM core flow rapid coastdown bypass status
- 0) MRBM main channelbypass status (k) MRBM main channel upscale rod block status
- 41) MRBM main channel downscale rod block status (m) MRBM main channelinoperative rod block status (n) MRBM main channel core flow abnormal rod block status I (c) o fRH Tip Sg M (5) CRT displays, which are part of the performance monitoring and control system, provide certain NMS-related displays and controls on the main control panel which are listed below:
(a) SRNM upscale trip / inoperative status (b) SRNM reactor period trip status (c) SRNM upscale rod block status (d) SRNM reactor period rod block status (c) SRNM downscale rod block status (f) SRNM bypass status (g) SRNM period historicalrecord (b) SRNM count rate historical record (i) SRNM period based permissive
- 0) LPRM string selectcd for status readings (k) LPRM neutron fluxlevel(Designated group of LPRMs displayed upon selection of certain single rod or gang of control rods)
(1) LPRM bypass status (m) LPRM neutron Dux downscale alarm status (n) LPRM neatron flux upscale alarm status (o) Number bypassed LPRMs and APRM channel (p) APRM simubted thermal power reactor trip status (q) APRM core ilow (r) Core flow his.orical record , (s) APRM neutr an flux (t) APRM simisated thermal power trip setpoint l (u) APRM simulated thermal power ' (v) APRM simulated thermal power record (w) Reference APRM downscale rod block status (One for each MRBM main channel) (x) MRBM main channelblocklevel status (y) MRBM main channel ups: ale (normal) rod block setpoint (z) MRBM main channel upscale (intermediate) rod block setpoint 74 23.2 Amendment 27
ABWR - 23sim, n, n i Standard Plant Table 7.6-5 REACTOR OPERATOR INFORMATION FOR NMS (Continued) , (aa) MRBM main channel upscale (low) rod block setpoint ' (ab) MRBM main channel upscale (normal) rod block setpoint historical record " (ac) MRBM main channel upscale (intermediate) rod block setpoint historical record (ad) MRBM main channel upscale (low) rod block setpoint historical record * (ae) MRBM subchannelinoperative status : (af) MRBM subchannel upscale rod block status (ag) MRBM subchannel downscale rod block status (ah) MRBM subchar ncl intermediate level transfer rate (ai) MRBM subchannel normallevel transfer rate - - ~ (aj) MRBM subchannel reading (ak) MRBM subchannel reading historical record (al) MRBM subchannel setup permissive
\ 1 t
(am) MRBM gain adjustrnent failed / , (an) No rod selected (MRBM) (ao) Peripheralrod selected (MRBM)
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ACRONYMS { (ctrl o[gt1 Th 54Att /- NMS - Neutron Monitoring System SRNM - Startup Range Neutron Monitor (AS) ol'd 'Y' P '; APRM - Average Power Range Monitor . l LPRM - Laal Power Range Monito'r'eProbe ATIP Automatic Traversing in-Cor j f MRBM - Multi-channel Rod Block MonitoD CRT Cathode RayTube l l l t. J 7.6-23.3 Aniendment 27 w - , - , = - , , , , . - - , - . , - - . - , . -..n - - - -- -
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% AA st 4 a 20 26 A B p LPRHs emD3 hp1 b OPRH Channels A, 6, C, b L tyyn 4p t,4< : Ip t & OfRH chenru/ 4 typ r n,91 y/e . : z ,,.d b () fen CAar,rre/ B l.n a r f'yk Jeb . Lp + 1'~ often cAer,ne / C Lower le{1 k He , ; Zepd f', opgn channe/ >
(la su < < , ru ny, v.6, r uan ode &s A8,0 D/zu Antf ) Ryu a M- / A L/>RM 12etec /~ 4%&f k crG, L Assipw h OPP' 9 den
- u Amplitude & Growth Rate Based Detection Algorithm JL JL lyes
~
If t>3(tp2 tp1) m seent sean i sean t lre - l rm lro no no N y
-> SCm ;f St>=51 ( *.] Set E If St>=S(t-dt) 21$
t j[if St =S(t-dt)E Set
-> ,g !" If T1<(tp2-tp1)<Thl'.llf St>=$3 tp2 t & St<=S(t+dt) t =t + dt t0-t & St>=S(t+dt) & St<=S(t+dt. ' 8 " S*' '
pj ,3, & sus 2 yes Ncrinnal Values of Parameters: 51 = 1,1 52 = 0.92 DR3 - 1.3 Smax = 1.3 Ti = 0.31 see scan t Th = 2.2 see i rm 53 = (Pt 1.0) x DR3 +1.0 y dt = 0.0$0 sec 4 tf St>=S(t-dt) Set e bsue trip St = (F#tered Fbi) / (Trne Averaged Flux) & St>=S(t+dt) tp3=t ~~if TI<(tp3 tp2)<Th (ritered Fbx : no Ngn fre<pency nones, Time Averaged Flux: Fitered w/ 6 see tme comtant) lre Period Based Detection Algorithm lm sean t scan t f'o
- to lro if Trren<TO< Trna -> Set U
rm - Sg N=0 ]['f st>=S(t dt) yes Set tp1 =t rf st<=S(ta) yes set j[ if st>=S(td, yes Set t0=t 5 St>.3(t+dt) & St<=S(t+dt) tp2=t D 3 " "
"' Y
g & St>=S(t+'c') T0-tp3-tp1 _ yes rf Trnin+te<TO<Trnan te to M Set N=N+1 F N>Np If St>=Sp 4 igu 4 Nominal Vabes of Parameters: Trrin = 1.0 see Trnax = 3.5 sec te = 0.15 sec
=~ lre no go = 10 Sp = 1.1 dl = 0.050 see St = (Fitered Fbu./
Time Averaged Flus) Figure 7.6 2A OPRM Logic}}