ML20150C968
| ML20150C968 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 03/17/1988 |
| From: | Kuemin J CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| TAC-66655, NUDOCS 8803230017 | |
| Download: ML20150C968 (32) | |
Text
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- l Consumers Power rowsmus niKH0GAN5 PR06Rs55 General Of fices: 1945 West Parnall Road, Jackson, MI 49201 e (517) 788-0550 March 17, 1988 Nuclear Regulatory Commission Document Control Desk Washingtri, DC 20555 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLANT -
RESPONSE TO REQUEST FOR INFORMATION ON POWER RANGE MONITORING INSTRUMENTATION (TAC 66655)
The NRC letter of March 7, 1988 requested additional information on the modifications to the Big Rock Point Plant power range monitoring instrumen-tation. The requested information, which is to support review of our Nc vember 9,1987 Technical Specifications Change Request, is contained in the enclosure to this lett er.
The NRC has also requested review of our 10C)R50.59 evaluation pertaining to the subject modifications. The evaluation which has been revised will be submitted following appropriate Plant Review Committee and Nuclear Safety Board review and concurrences.
James L Kuemin Staff Licensing Engineer CC Adminstrator, Region III, NRC NRC Resident inspector - Big Rock Point Attachment 0
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OC0388-0077-NLO4 8803230017 880317 PDH ADOCK 05000155
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l ATTACHMENT Consumers Power Company-Big Rock Point Plant Docket 50-155 RESPONSE TO REQUEST FOR INFORMATION ON POWER RANGE MONITORING INSTRUMENTATION (TAC No 66655).
March 17, 1988 '
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30 Pages 0C0388-0077-NLO4 i l
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ENCLOSURE Reply to the request of March 7,1988 for additional information on the Nuclear Measurement Analysis and Control DC Wide Range Monitor (NUMAC-DCWRM).
Big Rock Point Plant Docket No. 50-155
- 1. Request New instrument racks and indicators in the control room have been installed. New cables have been installed from the sensors to the new instrument racks and to the new indicators in the control room. Provide a detailed description of the separation criterion for the new cables and.
equipment and its conformance to Regulatory Guide 1.75 and IEEE-STD-384.
Compare this separation criterion to that currently utilized in the plant.
Response
l Installation of the NUMAC-DCWRM instrument assemblies (3) will be performed by utilization of chassis slides to accommodate use of the existing openings in the main control panel; new instrument racks will not be 1
utilized. l l
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2 The remote read-only operator display assemblies (3) will be located on the control console (benchboard) in the area previously occupied by analog meters / indicators which provide neutron flux monitoring information to operating personnel. Minor hardware changea will be required to the console facing to provide space for the display assemblies and at the same time, maintain the proper aesthetic values and human engineering requirements.
Signal and polarizing voltage cables to the existing detectors (eg, the detectors are not being replaced) from each channel will be replaced. The new cables will be routed from the control room, through the existing cable trays, electrical penetratiens and conduits presently used for the exiscing cables. As an additional feature to enhance equipment operation and reduce noise sevels, the new cables will be provided with extra-shielding by the addition of conduit in the cable tray runs. All new ,
cabling inter- and intra-panel wiring will be installed in a manner consistent with the existing installation at Big Rock Point Plant.
Big Rock Point Plant was built prior to the establishment of the requirements of Regulatory Guide 1.75 and IEEE-384. Separation / isolation criteria in accordance with these requirements was evaluated in accordance with the Systematic Evaluation Program (SEP) for Big Rock Point Plant.
Criteria for the isolation and separation of RPS components and their input parameters was evaluated to General Design Criterion (GDC24),
entitled "Separation of Protection and Control Systems"1 and IEEE-279-1971, l entitled "Criteria for Protection Systems for Nuclear Power Generating l
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3 Stations", Section 4.7.22 . As a result of this evaluation, the staff concluded 3 that suitable isolation devices exist in the Reactor Protection System (RPS) with the exception of possible effects from the motor generator sets and alternate feed. This exception was resolved by the implementation of plant modifications which the staff found acceptable.4 Additional isolation / separation will be provided upon installation of the :
DCWRM instrumentation, as the direct 12 volt' logic inputs to the RPS from the Neutron Monitoring System will be replaced by a relay logic network powered by the RPS low voltage power supply (see At.dchment 1).
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By letter dated September 16, 19865 the USNRC found the design of the )
NUMAC-LRM acceptable in regard to Conformance to Separation Criterion I
(R.G. 1.75). The NUMAC-DCWRM meets all of the same applicable regulatory -
requirements.s The interface criteria for its installation into existing I operating plant will be the same as for the original monitors, utilizing the external isolation devices and the power sources that the present l l
instruments use. l l
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- 2. Request After reviewing the NUMAC-LRM System (Topical Report NEDO-30883), it is the staff's understanding that the NUMAC-LRM is a single-channel instrument designed to be an exact replacement for Log Rad Monitors in existing systems. However, when used for safety related system application, it should conform to IEEE Standard 279-1971. Describe the conformance of the NUMAC-DCVRM system to IEEE Standard 279-1971 MIO388-0115A-BT01
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requirements for a protection system application. Although the mechanical design of this instrument permits it to replace several other neutron flux monitoring instruments in a single chassis, it should not compromise the channel separation requirements.
Response
The NUMAC-DCWRM is a single-channel instrument designed to be a monitoring instrument for intermediate and power level neutron flux ranges of a nuclear reactor. It is a functional and physical replacement for existing neutron flux monitoring equipment. When used for such purposes, conformance of the host system to IEEE Standard 279-1971 is preserved, including the use of multiple instruments where required. The staff has previously found this approach to be acceptable.5 At Big Rock Point Plant, three (3) such instruments (NUMAC-DCWRM) will be used to replace the existing intermediate and power range instrumentation. Installation of this new equipment will be performed in a manner consistent with the existing installation at Big Rock Point which was found to be previously acceptable.3 i
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- 3. Request Provide a detailed description of the isolation devices used between separation groups and between safety and non-safety systems. Provide a l
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detailed description of design criteria, tests performed and test results for all isolation devices utilized.
Response
As stated previously in the Response to Request No. 1, the 3
isolation / separation criteria at Big Rock Point Plant has been evaluated and found to be acceptable. The NUMAC-DCWRM is a single channel I
instrument designed to replace existing instruments. Each NUMAC-DCWRM contains a single input module (a second one cannot be effectively added) and, when applied in existing systems, utilizes both the same external isolation devices and power source as the instruments being replaced. A minor improvement in the Big Rock Point Plant installation is the benefit of additional isolation / separation via the use of a relay logic network to replace the direct 12 volt DC logic inputs to the RPS from the trip unit outputs of the Neutron Monitoring System flux level monitors.
4.
Request Provide a description of the design process and the design verification and validation steps utilized in the development of the software utilized for the updated neutron monitoring system.
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Response
In September, 1986, the USNRC accepted GE's Licensing Topical Report NED0-30883-A for the NUMAC Log Rad Monitor (LRM), the first Class IE NUMAC instrument.5 As part of its findings, the NRC Staff concluded that both GE's software design process and its software design validation and verification (V&V) steps met the intent of Regulatory Guide 1.152, Criteria for Programmable Digital Computer System Software (this Reg Guide was not available at the time the LRM was designed). The NRC further concluded that "(certain named) design measures and test procedures are reasonable to prevent the software program from cycling in a continuous loop and to defend against common mode failures."
From a hardware standpoint, the LRM and the Big Rock Point DCWRM designs are very similar. The instruments differ mainly in that the DCWRM performs a variety of software controlled functions not found in the LRM. However, the named design measures, software design process, and the V&V steps for both are the same.
The software design pro' cess incorporates the following basic steps:
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Preparation of software design specifications and division of software tasks into modules (individual software functions which can be separately specified, coded and tested).
Coding, code "walk-throughs", and testing of the individual modules.
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- Integration of individual modules and testing of combined module functions using emulation techniques.
System testing of the entire software package on the target machine (DCWRM, SRM, etc).
- Verification and Validation testing of the final software package against instrument requirements.
Several design features have been incorporated into the DCWRM (also the LRM and SRM) to defend against software (computer) failures:
Two computers are incorporated in the desigt, a "functional" CPU (Harris 80C86) which performs the safety-related tasks and a display controller (National NSC800) which operates the display (a non-safety related task). The only means of communication between them is via a serial data link (they do not share control or data buses). This helps to lessen the probability of a safety-related computer fault.
A self-test system operates in background which both detects hardware faults an examines certain data registers to see that they contain I
proper values. Faults detected by the self-test system are announced l by the downscale alarm and the downscale trip.
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- The functional computer incorporates a "watchdog timer". The CPU must reset a hardware timer approximately every 100 milliseconds. If not, the CPU is forced to reset thereby causing all relay outputs to trip.
Thus, if a "pror, ram glitch" occurs and the CPU becomes "lost", a "safe" action occurs and the operator is warned.
- When the functional computer requests data from one of the other modules, it releases control of the data bus to the module until the data is received. If data is not received within approximately 1 millisecond, a timeout occurs, the computer resumes control of the bus and continues on, and the lack of data will be flagged by the self-test system.
A (hardware) watchdog timer is provided on the I/O contact module which must be reset by the functional computer approximately every 70 milli-seconds. Failure to reset the timer causes all output relay coils to de-energize (ie, all contacts revert to the trip / alarm condition). Thus, if the functional computer gets "lost", a safe action occurs and the operator will be notified.
The DCWRM operates under the control of fixed programs stored in Electrically Programmable Read Only Memories (EPROMs). Operators and technicians cannot change these programs except through replacement of these EPROMs. When program modifications are required, the needed re-coding is performed by GE and new, re-validated EPROMs are provided for installation at the Big Rock Point site.
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Certain operating parameters (eg, the Downscale Trip and Alarm Points) are stored in non-volatile memory and can be adjusted within specified limits by operators and/or technicians. Such changes can only be made under keylock and password control.
Software for the DCWRM is developed and documented the same as hardware in accordance with the NRC approved Nuclear Energy Business Group Boiling Water Reactor Quality Assurance Program Description.7 Specifications appear either as published documents or are kept in Design Record Files (DRFs). Validation test plans and procedures, and similar documents are also maintained in DRFs. The object codes which determine instrument operation are installed in the DCWRM via Programmable Read Only Memories (PROMS) and uocumented on drawings that are under strict revision control. A design specification was prepared for each software component module and, after coding, cach module was tested. The modules were then assembled and tested informally using target hardware and full function emulators. Next, the software was entered in Programmable Read Only Memory (PROM) and installed in a DCWRM chassis for testing in accordance with Self-Test Integration and Software Validation Test Plans and Procedures. Testing results were documented with formal reports.
Finally, the combined hardware / software product was tested by the Quality 1
Assurance organization prior to shipment. I i
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- 5. Request Identify any major difference in hardware and software development between NUMAC-DCWRM system and NUMAC-IRM system (Topical Report NED0-30883).
Response
SYSTEM DESCRIPTION The NUMAC DCWRM monitors the neutron flux levels in the BWR core over the intermediate and power ranges of operation (IE-7% to 150% of full scale).
It is used with a compensated neutron sensitive ion chamber which provides current, proportional to the flux, to a Femtoammeter input module. A dual polarizing power supply module provides high voltage polarization voltages for excitation of a compensated ion chamber. A functional computer in the DCWRM processes the neutron flux using modularized microprocessor controlled hardware and firmware. An operator interface is provided which includes a multifunctional "pixel" display having digital and graphical presentations, status, and statistics related to flux, period and rate-of-power change functions. Analog outputs are provided for external linear flux, log flux, and period meters and recorders. Relay contacts are available for high flux and alarm trips. The DCWRM is a functional replacement for the following instruments in early BWR plants:
- Dual High Voltage Power Supplies for ion chambers.
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- Log-N Amplifiers for intermediate range monitoring.
- Picoammeters for power range monitoring.
HARDWARE CONFIGURATION Hardware configuration of the NUMAC-DCWRM is essentially identical to the LRM except that the quantity, type and arrangement of circuit boards and rear brackets and connectors varies with each NUMAC instrumer.t type, whereas the main chassis and motherboard, the display and keyboard assembly, the computer and analog modules, and low voltage power supply modules are common to all types. An optional read-only remote interface is also available for the operator front panels or benchboards.
The NUMAC-DCWRM consists of the following subsystems and modules: (1) an i essential microcomputer; (2) a high speed parallel data bus; (3) a >
serial data link; (4) neutron detector signal conditioning; (5) detector I power supplies; (6) analog input signal conditioaing; (7) trip and analog outputs; (8) two redundant instrument power supplies; (9) a I
display microprocessor, and (10) the front panel display. I l
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- 1. Essential Microcomputer - same as LRM
- 2. High Speed Parallel Data Bus - Same as LRM
- 3. Serial Data Link - Same as LRM MIO388-0115A-BT01
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- 4. Neutron Detector Signal Conditioning A Femtoammeter module measures low level detector input current and accurately converts it to a proportional output voltage for currents
, over a range of 1 x 10 ~14 to 1.5 x 10~3 amps. This module is the same as that used in the LRM, but is used over a wider input current range for the DCWRM.
- 5. Detector Power Supplies A dual high voltage power supply module provides two adjustable polarizing valtages for the compensated neutron detectors in the range of 0 to 1250 volts.
The four-channel discriminator module, normally used for pulse height discrimination with counting detectors, provides two D/A converters, which are driven by the function computer to control the two high voltage power supply output voltage levels.
- 6. Analog Input Signal Conditioning An analog module provides A/D conversion of analog inputs, such as low voltage power supply outputs, to a 16-bit digital signal which is sent to a parallel data bus. The essential microcomputer compares the digital readings from the analog module with trip settings to assure that they are within specified values.
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An isolated analog input module, used in some versions of the DCWRM, provides 11 channels of individual isolation amplifiers for accurate measurement of low level process variables. Each isolated signal is multiplexed by the analog module and sent to the parallel data bus. A 500 Hz sine wave generator in the isolated analog input module tests the operability of each channel.
- 7. Trip and Analog Outputs An I/O contact module drives five external relays which provide contacts for initiating trips and alarms. The module circuitry monitors the relay coil currents so that a comparison with the intended relay status will aid fault location diagnosis in the ,
event of abnormal operation. Relays can optionally be located either on the chassis or externally.
An analog module provides D/A conversion of selected signale from the parallel data bus to analog ouputs for remote displays, recorders, the plant process computer, and for auto calibration and the self-testing functions.
- 8. Rejundant Instrument Power Supplies - same as LRM
- r. Displav Computer and Front Panel - same as LRM MIO388-0115A-BT01
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FIRMWARE CONFIGURATION The firmware configuration (both function and display) is the same as the LRM.
SYSTEM OPERATION Lystem operation is essentially identical except that the instrument display is turned on and off in the Operate mode to extend screen life; it will automatically turn on in the event of a self-test failure or a trip.
Whenever the display is on, instrument reading, trip status and self-test status are shown along the top. The remainder of the display will depend on actions selected by the user.
DESIGN CONSIDERATIONS SAFETY CLASSIFICATION, ASPECTS l
i The NUMAC instrumentation can perform both safety-related and j non-safety-related functions. The DCWRM is qualified to perform on-line safety-related functions, and also non-safety-related operational and surveillance functions in accordance with its performance specifications.
If the Self-Test System detects a failure of safety-related functions, it causes a trip.
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15 INSTRUMENT POWER - same as LRM except that two types of internal power supplies are provided; a pair of low voltage power supplies and a dual high voltage power supply.
AC power input for the DCWRM is as follows:
Voltage 120V ac, 10%
Frequency 47 Hz to 63 Hz Current 0.7 Amperes, max continuous ENVIRONMENTAL CONDITIONS - same as LRM except as noted below:
Electromagnetic Interference The NUMAC-DCWRM will operate when exposed to conducted and radiated EMI-of following types:
EMI Frequency l Type Range Magnitude and Waveform l
Transients 100 - 500 Khz 0 to 300V p-p damped oscillations rf 500 Khz - 100 Mhz O to SV p p steady state MIO388-0115A-BT01
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16 Conducted Mode: EMI generator connected through a large capacitor to .120'/
ac power input lines of instrument to simulate power line EMI.
Radiated Mode: EMI generator radiating through 50 ft of terminated parallel conductors to signal input / output lines of instrument to simulate cable tray radiated EMI.
MECHANICAL DESIGN ASPECTS
- 1. General The mechanical design of this instrument permits it to replace several other neutron flux monitoring instruments.
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- 2. Dimensions l
1 The NUMAC-DCWRM chassis measures 7-in, high by 19-in. wide and is approximately 17.5-in. deep.
- 3. Weight - same as LRM
- 4. Modularity - same as LRM
- 5. Mounting - same as LRM MIO388-0115A-BT01
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- 6. Chassis - Same as LRM except that selected modules (dual high voltage power supply, femtoammeter) have direct high voltage and sensitive signal connections at the back edge of the module which do not go through the motherboard.
- 7. Fr nt Panel - same as LRM
- 8. Connections l All external connections are made through connectors mounted on a bracket located at the rear of the instrument with the exception of the detector excitation voltages which are obtained directly from a l l
connectors on the High Voltage Power Supply module and the signal l input connection on the femtoammeter module. The design accommodates both top and bottom entry cables when the instrument is installed in a panel or cabinet and takes into account the proper bend radii of connecting cables.
- 9. Color and Finish - same as LRM ELECTRICAL DESIGN ASPECTS
- 1. Measurement Section (Femtoammeter)
- a. Sensitivity MIO388-0115A-BT01
a 18 Sensitivity range is N 4E-14 to 1.5E-3 amperes.
- b. Period Based Trip A rate-of-increase monitor provides a signal to block control rod withdrawal and/or scram whenever the rate of core reactivity increase (period) exceeds a reference rate. A dynamic reference period, derived by amplifying and filtering the actual period, is compared with the actual period, and when the latter exceeds the j former due to a transient, the output signal is provided. The 1
range of the period-based trip is from -30 see to +3 see and is accurate to within 2% of full scale.
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- c. Accuracy at Recorder Output - same as LRM i
- d. Drift l
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1 The drift is not to exceed 5% of point over a 30-day period l l
following a two-hour stabilization under design center conditions.
- 2. Trip Outputs ,
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Same as LRM except that the number and functions are as specified for !
a particular application.
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- 3. Polarizing Power Supply Output Each channel has a separate dual high voltage power supply for polarizing its a:sociated compensated detector. Both sections of each
. dual supply are identical ekeept for the polarity. The characteristics of each power supply are the same as the LRM except as noted below:
Voltage Range: 0 to 1250V de i 10%
Maximum Current: 1.5 mamp over the entire output voltage range
- 4. Other outputs
- a. Each recorder output is proportional to the input current (may.
change with specific application). ,
Input Current Output s 4E-14 to 1.5E-3 amperes 0 to 1.0 Volt
- b. Each remote meter output is proportional to the input current (may change with specific application).
Input Current Output s 4E-14 to 1.5E-3 amperes 0 to 1.0 mA MIO388-0115A-BT01
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- c. Each process computer output (when required) is proportional to the input current.
Input Current Output N 4E-14 to 1.5E-3 amperes 0 to 160 mV
- d. Component Grade - same as LRM USER INTERFACE CONTROLS
- 1. Display Controller - same as LRM
- 2. Front Panel Display The user selects the information to be displayed on the front panel screen through the use of a keypad. The following information is generally available. Exactly what is displayed will depend upon each specific instrument plant application.
l The display is capable of working in conjunction with the front panel 1
operating keys as described for the LRM. Types cf information include: l l
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- Percent of full power in alphanumeric form
- Percent of full power in graphic forms (logarithmic and linear) ,
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- - Period and rate of change in alphanumeric and' graphic forms Trip settings and status Polarizing voltage level
- Alarma
- Self-test status
- Calibration results
- Diagnostic messages HELP messages
- 3. Front Panel Operating Keys - same as LRM l
- 4. Keylock Switch - sama as LRM
- a. Operate Mode - same as LRM except i
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th the t<, sh in the Operate mode, the DCWRM is ir the display j 1
L'#f possible to calibrate the instrument or change j w e- '. o ; f olarizing voltage settings. The soft keys are op > vi a a for the selection of alternate displays. The user' i
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22 may reset trip displays where appropriate. As long as the instrument is in the Operate mode, the functional computer sends data to the display controller, but not vice versa.
- b. Inop Mode When the keylock switch is in the Inop mode, the instrument is capable, on demand, of the following (a downscale trip of the instrument will occur in this mode):
Providing the previously specified items under the Operate mode. Unless otherwise specified for a particular application, the formats need not be the same.
Having the adjustable trip and polarizing vcitage setting 3 1
changed. !
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1 Being calibrated. l
- Self-test on a user demand basis, j Accepting user selected options. ,
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- Password 3 otection i
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S. HELP System - same as LRM
- 6. Remote Display A remote display interface is provided for operators for DCWRM information to be displayed in front row benchboards. The remote interface is read-only and, therefore, consists of the electro-luminescent display and a display control logic module, with function keys only.
RP.NTER CONTIGURATION - same as LRM SELF+ TEST CAPABILITY - ssme as LRM except that i 10% variance in the polarizing supplies, detection of a loss of a safety related function or placing the keylock switch in "INOP" will initiate a downscale trip ,
(receipt of a devascale trip will revert the configured RPS relay logic matrix to a 1 out of 2 logic, ie, an upscale trip on either of the two remainirg DM1n will scram the reactor).
CALIBRATION AND CPERATIONAL TESTS - same as LRM except as noted below:
1 Tests using internal circuitry can be performed on selected portions of the DOWRM to check operability as followa:
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- 1. Trips: When the instrument is in the Inop mode, an operator selected period trip (ramp) test can be performed under direction of the functional computer to test the trip output circuits. Trips can also be tested by operatur direct setting of the signal level to check the setpoint.
- 2. Microprocessors: Exercise of the self-test and calibration functions demonstrates operability of the microprocessors with high confidence.
- 3. Display: Detailed testing can be performed to test the front panel display and keys for proper operation.
- 6. Request The NUMAC-DCWRM system was designed for use in control room or similar 5 environments, not in "harsh" environments. Provide plant specific information that will assure that the NUMAC-DCWRM instrument will be operating within the environmental qualification limit.
Response
The NUMAC-DCWRM instrumentation will be insta}1ed in the centrol room at Big Rock Point Plant. The rating ot 0.5 mr/hr including a total integrated dose of 175 rads (eg, 40 years at 0.5 ar/hr) is not inconsisteor eith the original environmental design specifications for the Dag Rock Point Plant control room. Section 4.6.1.3 of the Big Rock Point Plant Final Hazards HIO388-0115A-BT01
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25 Summary Report 8 defines the control room as a Zone 1 area. Zone 1 areas are areas where maximum dose rates shall not exceed 0.5 mrem /hr. Current control room radiation level at approximately 85% reactor power is less than .1 mr/hr. Section 4.6.1.8 states that the control room is shielded to reduce the exposure to less than 0.5 rem during the first eight hours following a "maximum credible accident", a time period more than adequate to insure that the safety-functions of DCWRM are completed. Therefore, the qualification limits for the NUMAC-DCWRM are consistent with design radiation limfts for the control room at Big Rock Point Plant.
- 7. Request ,
Provide equipment qualification information of the detectors (gamma compensated ion chamber) and the interface requiraments with the NUMAC-DCWRM system.
Response
l As stated in the response to Request 1, the existing detectors are not being replaced. The ex'isting detectors are compatible with the ;
NUMAC-DCWRM to provide neutron flux level monitoring throughout the l 1
entire operating range of the Big Rock Point Plant reactor. l l
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The detectors and associated neutron monitoring system equipment at Big Rock Point Plant are not part of the plant Electrical Equipment Qualification (EEQ) list of equipment qualified for harsh environments in l
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, 1 26 accordance with 10CFR 50.49. .The Master Equipment List (MEL) for Big Rock Point Plant equipment was reviewed and accepted by the USNRC as a result of the special safety inspection conducted by USNRC representatives on September 15, through 19, 1986.9 The detectors are qualified to operate in the corral environment of the containment builditig at Big Rock Point Plant. The same type of detectors have been installed for over 25 yea.es of reactor operation with no known effects of damage due to adverse ensironmental conditions.
Environmental / performance specifications for the detectors are as follows:
GE Catalog No. 8NA01 (5467870G11)
Characteristics _
Neutron Sensitivity : 5.7E-14 amp /nv 15%
Gamma Sensitivity Uncompensated : 1.2E-11 amp /R/hr 120%
Compensated : <6E-13 amp /R/hr Neutron Flux Range : 2E01 to 9E11 nv f,perating Voltage Positive High Voltage: 20 - 2200V de Negative High Voltage: 20 - 2200V de Chamber Capacity Collector to +HV : 140 pf MIO388-0115C-BT01 ,
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+HV to Case : 190 pf
-HV to Collector : 22 pf Insulation Resistance : 2 1E13 ohms Gamma Compensation : 100 +0, -5%
Perturbation Factor : 0.0 Maximam Ratings Voltage : 3500v de Temperature : 320*C ,
Neutron Exposure (life): 1E20 nyt (for 50% reduction in sensitivity) 1 Pressure : 80 psig l l
Vibration : Designed to operate under conditions of I MIL-STD-167 l l
Shock : Designed to operate under conditions of shock per MIL-S-901C Interfacing of the detectors with the NUMAC-DCWRM instrumentation will be i
provided by direct connection of the coaxial cables from the detector to coaxial connector mounted on the Femtoammeter module (signal) and on the high voltage power supplies (pos4.tive and negative polarizing voltages).
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- 8. Request As described in the. licensee's submittal, Attachment 2 (Power Range Monitor System Description), Power Range Monitor trip contacts are connected to Reactor Protection System Channel 1 and Channel 2. Provide an electrical schematic diagram that illustrates that the channel separation and channel independence are preserved in this arrangement.
Response
An electric schematic diagram illustrating the existing and proposed (NUMAC-DCWRM) Reactor Protection System inputs for one channel of protection is shown on Attachment 1. Note that the relay logic network is designated 1, 2, 3, D1, D2, D3 to represent the trip inputs from the three FUMAC-DCWPM instruments. The notes describe relay operation.
References:
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- 1. General Design Criterion 24. "Separation of Protection and Control Systems," of Appe..,. dix A, "General Design Criteria for Nuclear Power Plants," 10 CFR Part 50, "Domestic Licensing of Production and Utilization Facilities" j l
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- 2. IEEE Standard 279-1971, "Criteria for Protection Gystems for Nuc1 car Power I l
Generating Staticus." ]
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- 3. Letter; SEP Topic VII - 1.A, ISOLATION OF REACTOR PROTECTION SYSTEM FROM NON-SAFETY SYSTEMS, INCLUDING QUALIFICATION OF ISOLATION DEVICES - FINAL SAFETY EVALUATION REPORT FOR BIG ROCK POINT NUCLEAR POWER PLANT, September 02, 1982
- 4. NUREG-0828, Integrated Plant Safety Assessment, Systematic Evaluation Program, Big Rock Point Plant, Section 4.22.
- 5. Letter; GC Lainas, Asst Dir, Div of BWR Licensing to D.J. Robare, General Electric Company, entitled, "ACCEPTANCE FOR REFERENCING OF LICENSING TOPICAL REPORT NED0-30883, "THE NUCLEAR MEASUREMENT ANALYSIS AND CONTROL LOGARITHMIC RADIATION MONITOR (NUMAC - LRM)", September 16, 1986.
- 6. NEDO-31399. "The Nuclear Measurement Analysis and Control DC Wide Range Monitor (NUMAC-DCWRM)", General Eeletric Company, April 1987.
- 7. NEDO-11209-04A, Revision 7. "Nuclear Energy Business Operations Quality Assurance Program, General Electric Company, May 15, 1987.
- 8. "Final Hazards Summary R ' eport," Vol.1, "Plant Technical Description and Safeguards Evaluation", Revised March 1962.
l l
l MIO388-0115C-BT01
a ** G l
- l l
ATTACHMENT 1 NEITTRON MONITORING SYSTEM REACTOR PROTECTION SYSTEM INPtrrs EXISTING CONFIGURATION l
se ear b toes
. I se esc
- 1) Neutron Meettering Channels 1. 2 sad 3 f C***WL ' bh' trip at 41201 power for combination with
" Md'# 4 h h
~
w drunseale trip at 151). i g) y g~ nu a -
- 2) Neutron Monitoring Channels L, 2 and 3 g
3 {a '
g Per* c.rM/ 4
-+:h.
t ups: ale-dcwnscale coincident trip is bpassed with all three power channel
. , _],. range switches in the 40 x 10 11 power 7 f ,' ,% , , ,,g ., j ,
)d _,
M position or below.
}w <
- 3) Neutron Monitoring Channels 1, 2 and 3 N!* d [' upscale-downscale relaying is part of the y' ?## #M d ?'h_ Neutron Monitoring systes tetp output logic.
CMwit S rep ng rpshd %>~ 4) 116 relay contacts are closed (ie, short C ' period trip bypass) with two of three power channel range switches in the 41 power
/ &" > b" position (actual bypass operation occurs at
, 2
- T 53 approximately 60 to 703 of the 1.251 power NNO s/msa ,1r positten er at 0.75 to 0.8751 power vbes the
,- W switching operation is perf ormed).
y,8a
- 4_4 e g? y i
Aft 2fegs Atmase TD regrut avs retase y gmy; y g an Trn Teo* DisM3 (M 8/283Y Jng)
FIGURE 1 PROPOSED CONFIGURATION Notest p a s o$ rat.
a; 1) Neutron Monitoring Channels 1. 2 and 3 i W f
!) M
. 3, g
y -.w- DCVRM "R1-51 TRIP" occurs at 31201 povert
$10 second period when below 11 power or M
ag a ' 'J 4 fast power rate when above it power (ie.
':' I lh 8
8.a , y
- free 11 to 502 power 450 MWt/ minute from 50! to 83.31 power ato MWt/ minute),
Contacts I, 2 and 3 open on"BI-El TRIF" j
4 h"' &
'i 1= HHb ~~~)b 1 3 ~
- 2) Contacts 91. D2 and D3 open upon instrument k)M as F
C down-ocale (1 a 10~71 power), high voltage
- 3 power supply f ailure (+ or - or both at 1
,f*D 101 of voltage setting of 800V DC), key lock W switch is "!NOP" position or "Fatal Fault
- wr vsep 4 y)) in dWAC DCVRM hardware /firmware. Opening of these contacts "sets up" the upscale- l
~b-' downscala trip logic to provide reactor C
screa on a "111-81 TltF" f rom another S'S ^ channel.
se ac t eff) j '
,Le l 1 Nr'eD.a . . .N.. .s,i, t , ;
rs .< ~ oa, cr.e
- man m,o novas 4 9e asaw, e sov *#
FIGURE 2 i
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