Term
| Explain the purpose and function of the LPRM and APRM systems. |
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Definition
The PRM signal is used to: Provide the reactor operator with reactor power level. Provide input signals to the RPS and RMCS to assure that local power density and average power level limits are not exceeded.
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Term
| "Identify the normal, alternate, and or emergency power supplies for major LPRM and APRM system components." |
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Definition
| "Primary power (120 Vac) for the PRM system is provided from bus A (Y-50) and bus B (Y-40) of the RPS Power Distribution System. ARPM Channels 1,2 and 3 and RBM Channel 7 are connected to bus A. The remaining channels receive their primary power from bus B. Instrument bus power (120 Vac) is supplied to the power level recorders..." |
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Term
| Functional and component relationships between the LPRM and the APRM system |
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Definition
| LPRMs provide input to the associated APRMs. A downscale LPRM reading will result in a lower reading for the associated APRM. An upscale reading may result in a hi or hi hi trip condition for the associated APRM and associated RPS trip. A change in a LPRM reading will affect the associated APRM AGAF readings. |
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Term
| Functional and component relationships between the LPRM system and the Process computer |
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Definition
| Uses TIP system data to calculate gain adjustments for the LPRMs. The follwing supply inputs to the plant process computer: 1. Flow converter analog output signals; 2) COMPARATOR or UPSCALE/INOP digital alarms; 3) The output of the LPRM flux amplifier; 4) The output of each APRM averaging amplifier. |
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Term
| Functional and component relationships between the LPRM system and the RBM system |
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Definition
| RBM: provides LPRM inputs to the RBM averaging amplifier. LPRM signal is also sent to the RBM input count circuit for minimum input requirements; |
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Term
| Functional and component relationships between the LPRM system and the Gardel system |
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Definition
| "Gardel uses LPRM signals porvided by the process computer to provide information such as thermal power, flux profiles, etc." |
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Term
| Functional and component relationships between the APRM system and the LPRM system |
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Definition
| LPRMs provide input to the associated APRMs. A downscale LPRM reading will result in a lower reading for the associated APRM. An upscale reading may result in a hi or hi hi trip condition for the associated APRM and associated RPS trip. A change in a LPRM reading will affect the associated APRM AGAF readings. |
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Term
| Functional and component relationships between the APRM system and the Rod block monitor (RBM) |
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Definition
| "A failure of the APRM to the RBM input will cause the RBM to become INOP, generating a rod block. A misadjusted APRM input to the RBM may cause the RBM to initiate a rod block at lower or higher power (possible high local power)." |
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Term
| Functional and component relationships between the APRM system and the Reactor recirc system |
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Definition
| Receives total recirc loop flow for use in establishing the scram/ rod block trip settings. |
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Term
| Functional and component relationships between the APRM system and the RPS |
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Definition
| "RPS bus A supplies APRMs 1, 2 and 3. RPS bus B supplies APRMs 4, 5 and 6. PRMs provide a trip signal to RPS to initiate a scram. A loss of either power supply will result in a trip of the associated APRMs and a half scram. A rod block will also be initiated." |
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Term
| Functional and component relationships between the APRM system and the RMCS |
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Definition
| RMCS provides rod block trip signals to prevent a rise in reactor power by control rod motion. |
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Term
| Functional and component relationships between the APRM system and the Process computer |
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Definition
| Uses TIP system data to calculate gain adjustments for the LPRMs. The follwing supply inputs to the plant process computer: 1. Flow converter analog output signals; 2) COMPARATOR or UPSCALE/INOP digital alarms; 3) The output of the LPRM flux amplifier; 4) The output of each APRM averaging amplifier. |
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Term
| Causes of Detector LPRM failures |
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Definition
Depletion of Uranium; Mechanical failure: Seal failure would result in loss of argon gas which would result in loss of sensitivity and lowering signal output. Cable insulation breakdown could cause a short to ground or other electrical source (indications may go high or low) Insulator failure (between concentric cylinders) could cause a short between electrodes, failing output high. 'Whiskers' and shorts (frayed and loose wires may short electrodes to each other or to ground."
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Term
| Predict the impact/consequences of Loss of ion chamber power supply on LPRM |
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Definition
| Loss of power supply will result in LPRM downscales. |
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Term
| Causes of Detector LPRM failures |
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Definition
Depletion of Uranium; Mechanical failure: - Seal failure would result in loss of argon gas which would result in loss of sensitivity and lowering signal output.
- Cable insulation breakdown could cause a short to ground or other electrical source (indications may go high or low)
- Insulator failure (between concentric cylinders) could cause a short between electrodes, failing output high.
- 'Whiskers' and shorts (frayed and loose wires may short electrodes to each other or to ground.
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Term
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Definition
| Designed to continuously monitor the neutron flux level in the reactor. Signals must be available to permit demonstration of compliance to the critical power ratio limits with a speed and ease consistent with efficient operation of the plant. |
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Term
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Definition
| "To provide a continuous, accurate indication of the core average power. Must perform this function even in the worst permitted LPRM bypass and failure condition and continue to perform its function following single component failure within the subsystem." |
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Term
| Tech Spec 3.3.1.1 LCO/Applicability and Conditions with less than or equal to one hour completion time |
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Definition
"Section 3.3: Instrumentation Tech Spec 3.3.1.1 Reactor Protection System (RPS) Instrumentation LCO 3.3.1.1: The RPS instrumentation for each Function in Table 3.3.1.1-1 shall be OPERABLE; APPLICABILITY: According to Table 3.3.1.1-1; CONDITION C: One ore more Functions with RPS trip capability not maintained. REQUIRED ACTION C.1: Restore RPS trip capability; COMPLETION TIME: 1 hour. CONDITION D: Required Action and associated Completion Time of Condition (A, B,) or C not met. REQUIRED ACTION D.1: Enter the Condition referenced in Table 3.3.1.1-1 for the Channel. COMPLETION TIME: Immediately. NOTE: for ARMs, the step referenced in the table 'F'. REQUIRED ACTION F.1: Be in MODE 2; COMPLETION TIME: 6 hours AND REQUIRED ACTION F.2: --NOTE-- Only Applicable to Main Steam Isolation Valve closure... |
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Term
| TRM 3.3.2.1 LCO/Applicability and Conditions with less than or equal to one hour completion time |
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Definition
"Section 3.3: Instrumentation. TRM 3.3.2.1: Control Rod Block Instrumentation. TLCO 3.3.2.1: The control rod block instrumentation for each Function in Table 3.3.2.1-1 shall be OPERABLE. CONDITION B: --NOTE-- Only applicable to Functions 1,2 and 3 (SRMs, IRM, and APRMs). One or more functions with two required channels inoperable. REQUIRED ACTION B.1: Place channel in the tripped condition OR B.2 Suspend control rod withdrawal. BOTH COMPLETION TIMES: IMMEDIATELY. CONDITION C: One or more required functions with 4 channels inoperable. REQUIRED ACTION C.1 Place channel in the tripped condition. OR C.2 Suspend control rod withdrawal. BOTH COMPLETION TIMES are IMMEDIATELY." |
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Term
| Function of (LPRM) In-Core Detectors |
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Definition
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Term
| Function of (LPRM) Ion Chamber Power Supply |
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Definition
| Convert 120 Vac to 100 Vdc for use with the fission chamber detectors. |
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Term
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Definition
| Contains a flux amplifier which converts its associated detector current signal to a voltage signal. |
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Term
| Function of (APRM) Averaging Amplifier |
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Definition
| Accepts the 24 LPRM input signals and produces an output signal proportional to the average of the input signals. |
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Term
| Function of (APRM) Calibrator |
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Definition
| Provides an adjustable precision current signal which is used to calibrate the LPRM channels assigned to an APRM. |
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Term
| Function of (APRM) Count Circuit |
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Definition
Monitors the number of LPRM channels operating in each APRM channel. If more than a preset minimum number are bypassed or removed, an APRM INOP trip will occur. Per B.05.01.02-02: "All APRM Count Circuits are set to trip at 6 LPRMs bypassed." |
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Term
| Function of (APRM) Recirc Flow Converter and Aux Unit |
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Definition
| Provides recirc loop flow signals for use in setting flow-biased APRM HI rod withdrawal block and APRM HI-HI scram functions. |
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Term
| Function of (ARPM) Quad Trip Unit |
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Definition
Provide trip signals (rod block or scram). APRM HI HI UPSCALE (flow-biased reference calc or 119.5% (clamp) results in scram signal; APRM HI UPSCALE (flow biased reference calc or 107.5% (clamp) results in a rod block signal); APRM DOWNSCALE (3.5%); APRM INOP (mode switch out of OPERATE, Removal of circuit board, Number of LPRMs drops below minmum required, Loss of power)
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Term
| Which LPRM trips are seal-in and which are auto-reset? |
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Definition
| "LPRM trips on C-37 seal in. On C-05, they are auto-reset." |
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Term
| Description of APRM system Operation |
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Definition
"Provides overall power range monitoring, the range monitored is from approximately 3 to 100% power. Six channels are provided which average selected groups of LPRM signals and provide output signals that are proportional to average neutron flux. Trip circuits associated with each channel provide trip output signals to the RMCS rod withdrawal block circuits and the RPS scram circuitry. MUST be two operable in each RPS locic channel." |
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Term
| Describe the coating on the LPRM detectors |
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Definition
| The active length of the outer cylinder is coated with 90% enriched U-235. U-234 is added to the coating to extend the neutronic lifetime of the detector. |
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Term
| Describe the basic principle of the LPRM detector |
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Definition
| "The (Argon) gas between the electrodes is ionized by the passage of charged particles which are released when the U-235 in the detector coating fissions. The negative ions produced are accelerated to, and collected by, the inner electrode. The resulting current flow (of electons) is proportional to the neutron flux and is the input to the flux amplifier." |
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Term
| What is the voltage of the LPRM High Volts power supply? |
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Definition
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Term
| Where is the output of the LPRM flux amplifier applied? |
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Definition
LPRM upscale and downscale trip circuits; Plant process computer (analog input); Rod block monitor
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Term
| Discuss the three positions of the thumbwheel mode selector switch on each LPRM card. |
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Definition
Operate: connected to the input of the LRPM flux amplifier; Calibrate: in-core input is replaced with… Bypass:…
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Term
| Description of System Design (LPRM) |
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Definition
| Designed to continuously monitor the neutron flux level in the reactor. A sufficient number of detectors is required to ensure the local neutron flux is known to an accuracy consistent with core deign. The LPRM subsystem signals must be available to permit demonstration of compliance to the critical power ratio limits with a speed and ease consistent with efficient operation of the plant. |
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Term
| Description of System Design (APRM) |
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Definition
| "Designed to provide a continuous, accurate indication of the core average power. Must perform this function even in the worst permitted bypass and failure condition and continue to perform its function following single component failure within the subsystem." |
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Term
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Definition
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Term
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Definition
| 24 strings with 4 detectors per string |
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