State the purpose of the safety system as given in the HFIR Safety System description.

"Fill in the Blank The purpose of the safety system is to _________ the control system and quickly shut the reactor down should any of the __________ exceed preset values."

"Fill in the Blank The purpose of the safety system is to override the control system and quickly ________ should any of the parameters affecting safety exceed _________."

"True/False The purpose of the safety system is to override the control system and quickly shut the reactor down should any of the parameters affecting safety exceed preset values."

"True/False The purpose of the safety system is to transmit signals to the control system to shut the reactor down should any of the parameters affecting safety exceed preset values."

"Fill in the Blank The HFIR Safety System utilizes uncompensated ion chambers to detect and transmit a signal proportional to the __________."

"Fill in the Blank The HFIR Safety System utilizes uncompensated _________ to detect and transmit a signal proportional to the neutron flux."

"Fill in the Blank The safety channel flux amplifiers receive a current proportional to the neutron flux from the ionization chamber and produces an output voltage proportional to a ___________________."

"Which of the following safety channel components receives a current proportional to the neutron flux from the ionization chamber and produces an output voltage proportional to a percentage of the selected power range? A. Chamber Voltage Monitor and Test Unit B. Flux Amplifier C. Flux Reset Module D. "OR" Gate"

"Fill in the Blank The chamber voltage monitor and test unit serves two functions in the safety system. It monitors voltage supplied to the _________ and provides a method of testing the safety system response to a high ________ level by introducing a core power increase at a rate of approximately 10%/sec, and a high rate of rise by introducing a core power increase at a rate of approximately 30% /sec."

"True/False In addition to a separate voltage supply each safety channel is provided with a chamber voltage monitor and test unit which serves two functions in the safety system. It monitors voltage supplied to the ionization chambers and provides a method of testing the safety system response to a high neutron flux level by introducing a core power increase at a rate of approximately 10%/sec, and a high rate of rise by introducing a core power increase at a rate of approximately 30% /sec."

"True/False In addition to a separate voltage supply each safety channel is provided with a chamber voltage monitor and test unit which serves two functions in the safety system. It monitors voltage supplied to the ionization chambers and provides a method of testing the gamma attenuation provided by the pulse height descriminator."

What is the purpose of the after heat computer in the safety channels?

"Fill in the Blank The purpose of the after heat computer in a safety channel is to compensate for the difference in neutron flux level and _________, due to decay heat, during a large _________ power transient."

"Fill in the Blank The purpose of the after heat computer in a safety channel is to compensate for the difference in neutron flux level and _________, due to decay heat, during a large _________ power transient."

The after heat computer in each safety channel compensates for the difference in what two parameters during a large down power transient?

"True/False The flux reset feature continuously calibrates the reset flux signal against the measured heat power to compensate for gradual changes in flux distribution over core lifetime."

"True/False The flux reset feature continuously calibrates the reset flux signal against the measured heat power to compensate for gradual changes in detector sensitivity during core lifetime."

What purpose does the flux reset feature serve in a safety channel?

"Fill in the Blank The Safety System continuously monitors reactor inlet and outlet temperature for use in the high __________, the ___________, and the computation of heat power."

State two of the three purposes for which the safety system monitors reactor inlet and outlet temperature.

"Fill in the Blank The Safety System monitors primary system flow for use in computing heat power, __________, and _________ fast reverse and scram."

State two purposes for which the safety signal monitors primary system flow.

"Fill in the Blank The safety system heat power computers develop a signal proportional to the reactor heat power in megawatts to supply a __________, the flux reset mechanism, a __________, and a heat power run permissive circuit."

"Fill in the Blank The heat power computer develops a signal proportional to the reactor heat power in megawatts to supply a heat power scram, the _________, a high heat power reverse, and a __________."

State two purposes for which the safety system uses the signal generated by the heat power computer.

"Fill in the Blank The safety system vessel pressure switches monitor reactor vessel pressure for use in the __________ and the ___________."

State the two functions provided by the vessel pressure switches monitored by the safety system.

"Fill in the Blank The FFED system monitors gross coolant activity as close to the core exit as possible to limit the release of fission products should a __________."

"Fill in the Blank The FFED system monitors __________ as close to the core exit as possible to limit the release of fission products should a breach occur in the __________."

"True/False The Safety Channel Power Supplies, located in drawer S-2, regulate instrument battery voltage to various voltages used by the equipment in the safety channel drawers."

"True/False The Safety Channel Power Supplies, located in drawer S-2, regulate the 120 volts from P-1A to the various voltages used by the equipment in the safety channel drawers."

"Fill in the Blank In the safety system, fast trip comparators are used to monitor various process parameters and provide a signal for a _________or an __________ upon detection of an unsafe condition."

"True/False Fast trip comparators provide for both fast scrams and auxiliary control actions in the safety system."

"True/False Fast scrams is the only function provided by the fast trip comparators in the safety system."

The OR gate in each safety channel monitors the output of what components? What is controlled by the output of the OR gate?

"Fill in the Blanks The OR gate in each safety channel monitors the output of the scram comparators and turns off the ____________ when one or more comparator's output goes to __________."

To how many control plate magnet coils does EACH safety channel magnet amplifier provide power?

What function does the safety channel magnet amplifiers perform?

"True/False The slow scram circuit provides administrative control over the reactor to ensure that certain important conditions are met for the operation of the reactor."

"True/False The purpose of the slow scram circuit is to override the control system and quickly shut the reactor down should any of the parameters affecting safety exceed preset values."

"True/False The inner cylinder shim inhibit serves to inhibit the shim motor withdrawal of the inner cylinder upon the event of a scram."

"True/False The inner cylinder shim inhibit serves to inhibit the servo motors upon the event of a scram."

What is the purpose of the inner cylinder shim inhibit?

"Fill in the Blank The safety system ion chambers are located in _________ which penetrate the reactor ________."

"True/False The safety system ion chambers are held in the reactor vessel thimbles with latches which hold them in a fixed position."

"True/False The safety system ion chamber assemblies are held in the reactor vessel thimbles with remotely adjustable positioners."

Where are the safety channel temperature transmitters located?

"True/False Each safety channel temperature detector has an individual temperature transmitter located at the instrument monitoring platform in the experiment room."

"True/False Each safety channel temperature detector has an individual temperature transmitter located at the beam room transmitter rack."

Where are the safety channel flow transmitters located?

"True/False The primary coolant flow rate signals are obtained from measurement of the differential pressure developed across the primary coolant flow Venturi FE-100. The instrument taps are extended through the pipe tunnel wall to the differential pressure transmitters located at the beam room transmitter rack."

"True/False The primary coolant flow rate signals are obtained from measurement of the differential pressure developed across the primary coolant flow Venturi FE-100. The instrument taps are extended through the pipe tunnel wall to the differential pressure transmitters located at the instrument monitoring platform in the experiment room."

"Fill in the Blank Each of the safety channel flow instruments have their own individual power supplies; EM-100-1, -2, and -3 for the high range and EM-100-1B, -2B and -3B for low range, located in the _________."

Each of the safety flow instruments have their own individual power supplies; EM-100-1, -2, and -3 for the high range and EM-100-1B, -2B and -3B for low range. Where are these power supplies located?

"Fill in the Blank The heat power computer for each channel is located in the safety channel cabinet in the _________."

Where are the safety channel heat power computers located?

"True/False The reactor vessel pressure is monitored for the safety system at the vessel penetration RH-8. The instrument tap is extended through the pipe tunnel wall to a series of pressure switches located at the beam room transmitter rack."

"True/False The reactor vessel pressure is monitored for the safety system at the vessel penetration RH-8. The instrument tap is extended through the pipe tunnel wall to a series of pressure switches located at the experiment room monitoring platform."

Where are the FFED ionization chambers located?

"True/False The FFED ionization chambers are located next to the vessel exit water line at it's point of entry into the pipe tunnel."

"True/False The FFED ionization chambers are located next to the vessel inlet water line at it's point of entry into the pipe tunnel."

Describe the design of the ionization chambers used for the Safety and Servo systems.

"True/False The HFIR utilizes special design multiple section ion chambers. Each chamber serves a single safety channel and a single regulating channel. The current design incorporates two separate chambers in a common housing."

"True/False The HFIR utilizes special design multiple section ion chambers. Each chamber serves a single safety channel and a single regulating channel. The current design incorporates three separate chambers in a common housing."

What type of temperature sensor is utilized in the Safety System?

"True/False The safety system temperature sensors are dry well resistance type temperature detectors."

"True/False The safety system temperature sensors are dry well gas capillary tube type temperature detectors."

"Fill in the Blank The safety system utilizes the 128 pressure system which has three _________ contact digital-electronic type pressure switches."

"Fill in the Blank The safety system utilizes the _________ pressure system which has three dual contact digital-electronic type pressure switches."

Each Safety Channel ionization chamber has a power supply in drawer S-3. From where do the power supplies receive their power?

"True/False The ionization chamber power supplies are provided with 32 v dc from the Instrument Power system through P-31, P-32, and P-33."

"True/False The ionization chamber power supplies are provided with 120 v ac from the Instrument Power system through P-1A."

"True/False The safety temperature transmitters are supplied with AC power from the static invertors."

"True/False The safety temperature transmitters are supplied with 32 v dc from P-31, P-32, and P-33."

From where do the safety system temperature transmitters receive their power?

"True/False Each of the safety system flow instruments have their own individual power supplies; EM-100-1, -2, and -3 for the high range and EM-100-1B, -2B and -3B for the low range. The power supplies are supplied with 118 v ac from the static invertors."

"True/False Each of the safety system flow instruments have their own individual power supplies; EM-100-1, -2, and -3 for the high range and EM-100-1B, -2B and -3B for the low range. The power supplies are supplied with 120 v ac from P-1B."

From where do the power supplies for the safety system flow transmitters receive their power?

"True/False The safety system utilizes the 128 pressure system which has three dual contact digital-electronic type pressure switches. The pressure switches are powered from the static invertors and fail to the trip position on a loss of power."

"True/False The safety system utilizes the 128 pressure system which has three dual contact digital-electronic type pressure switches. The pressure switches are powered from P-1B and fail to the trip position on a loss of power."

From where do the safety system pressure switches receive their power?

"True/False Power for the safety systems magnet amplifiers is supplied from P-31, 32, and 33."

"True/False Power for the safety system magnet amplifiers is supplied from the static invertors."

From where do the safety system magnet amplifiers receive their power?

How do ionization chambers in the safety system detect neutrons?

"Fill in the Blanks Ionization Chambers in the safety system detect neutrons by collecting the __________ produced when the neutrons interact with the _________ inside the chamber."

"True/False The safety system flux amplifiers are variable gain operational amps. By proper choice of a feedback resistor the amplifier output voltage for a given percentage of power for a mode is the same in all three modes of operation."

"True/False The safety system flux amplifiers receive a current proportional to the neutron flux from the ionization chamber and produce an output voltage proportional to the power level. The sensitivity of the channel is changed as required for operations in modes 2 and 3 by remotely changing the reference voltage on the trip comparators."

The purpose of the after heat computer is to compensate for the difference in neutron flux level and actual core power, due to decay heat, during a large down power transient. How does the after heat computer accomplish this function?

"Fill in the Blank The purpose of the after heat computer is to compensate for the difference in neutron flux level and actual core power, due to decay heat, during a large down power transient. In order to cope with the after heat problem, the fission product heating is approximated ___________________."

"Fill in the Blank In order to compensate for gradual changes in neutron flux distribution the reset flux module continuously compares the __________ signal to the more accurate __________ signal. The voltage multiplier multiplies the error voltage with the voltage from the output of the flux amplifier producing a new corrected reset flux signal."

"Fill in the Blank In order to compensate for gradual changes in neutron flux distribution the reset flux module continuously compares the __________ signal to the more accurate __________ signal. The voltage multiplier multiplies the error voltage with the voltage from the output of the flux amplifier producing a new corrected reset flux signal."

How does the Flux Reset module function to compensate for the gradual changes in flux distribution over core lifetime?

"The safety system has both a high range and a low range flow transmitter for each channel. A. The high range transmitter develops a signal proportional to what range of flow? B. The low range transmitter develops a signal proportional to what range of flow? C. For what purpose(s), other than indication, is the low range transmitter signal used in the safety system?"

"True/False The safety system low range "B" flow transmitters develop a 4 to 20 ma current signal for flows in the range of 0 to 20% of full flow. Other than indication, this signal is used only for the "Low-Low Flow" scram."

"True/False The safety system low range "B" flow transmitters develop a 4 to 20 ma current signal for flows in the range of 0 to 50% of full flow. Other than indication, this signal is used only for the "Low-Low Flow" scram."

The operation of the FFED ionization chambers is essentially the same as the safety system neutron flux chambers, with one exception. What is the difference in the chambers which makes their operation different?

"Fill in the Blanks The operation of the FFED ionization chambers is essentially the same as the safety system neutron flux chambers, with the exception that they do not have the _________ coating or gas to make them sensitive to __________."

"Fill in the Blank Each safety channel has three independent voltage regulators which receive power from the instrument batteries. The voltage regulators produce ________ different dc voltages which are used by various equipment in the safety channel drawers."