Rad Monitoring Flashcards
What is the purpose of rad monitoring system?
Servew to warn plant personnel of rising radiation levels in various plant areas.
Each typical analog ARM RIA has the following controls and indications:
Two-scale analog meter
Nine-position function selector switch
Alarm, alert, and reset lamps/pushbuttons
Each typical analog ARM RIA has a two scale meter that indicates what?
Two-scale analog meter – provides measured radiation field indication
- Red scale spans eight decades, from 10-1 mR/hr to 107 mR/hr
- Black scale spans three decades with selectable range
- Specific range is selected using the function selector switch.
Each typical analog ARM RIA has Nine-position function selector switch that does what?
Nine-position function selector switch
“OFF” – removes power from analog meter and detector, but not from alarm lamps
- Causes channel failure and initiates channel failure annunciator
- Does not cause a high radiation alarm for the affected channel
“ALL” – output signal is scaled for red scale
- 10-1 mR/hr to 107 mR/hr
The following positions are read on the black scale:
- “107” – scales output signal to indicate from 104 mR/hr to 107
- “106” – scales output signal to indicate from 103 mR/hr to 106
- “105” – scales output signal to indicate from 102 mR/hr to 105
- “104” – scales output signal to indicate from 10 mR/hr to 104
- “103” – scales output signal to indicate from 1 mR/hr to 103 mR/hr
- “102” – scales output signal to indicate from 10-1 mR/hr to 102 mR/hr
“CS” – unshields a local check source at the detector; meter indicates on the “102“ black scale
Each typical analog ARM RIA has three push buttons that do what?
High Alarm (Red)
- Lamp lit high alarm setpoint met and/or exceeded.
- Pressing the lamp pushbutton indicates the setpoint on the analog meter.
- Generally set two to ten times normal background for that area
Alert Alarm (Yellow)
- Not connected; has no function
- Pressing the lamp pushbutton brings in circuit failure alarm
Reset (Green)
- When lit it indicates power available and reading > 10-1 mR/hr
- Resets the high alarm if level has dropped below the high setpoint. Otherwise it will alarm again.
What are Containment Gamma Monitors – RIA 2321/2322?
Containment Gamma Monitors – RIA 2321/2322
Also known as the Containment High Range Radiation Monitors
Different from the typical Analog RIA
- Two-scale analog meter (same as typical)
- Eight-position function selector switch
- Alarm, safe/reset, and test lamps/pushbuttons
Containment Gamma Monitors – RIA 2321/2322 buttons function to do what?
High Alarm (Red)
- Lamp lit high alarm setpoint met and/or exceeded.
- Pressing the lamp pushbutton indicates the setpoint on the analog meter.
- 400R/hr
Alert Alarm (Yellow)
- Lamp lit high alarm setpoint met and/or exceeded.
- Pressing the lamp pushbutton indicates the setpoint on the analog meter.
- 40R/hr
Safe/Reset (Green)
- When lit it indicates power available and reading > 1 R/hr
- Resets the alert and high alarm if level has dropped below the high setpoint. Otherwise it will alarm again.
- Indicates last self-check was completed SAT
Channel Test (Blue)
- Only functions if selector switch is in Test
Containment Gamma Monitors – RIA 2321/2322 Channel Test “Blue” button does what?
Containment Gamma Monitors – RIA 2321/2322 Channel Test “Blue” button
With selctor switch in “TEST”
Pressing and holding the blue “Channel Test” button causes
- Alert, High, and Channel Test lamps immediately illuminate
- Brings in EK-0225 [0226], “CONT GAMMA RIA‑2321 [RIA-2322] FAIL”
Release the button
- High and Alert lamps should extinguish
- Green safe lamp will extinguish only if the local radiation field is less than 1 R/hr.
Containment Gamma Monitors – RIA 2321/2322 self test?
Containment Gamma Monitors – RIA 2321/2322 self test
Every 17.1 minutes, each Containment Gamma Monitor undergoes an automatically initiated self-test using an internal electronic check source (ECS).
Also initiated with selector switch in test and pushing “ECS Test Button”
Test last six seconds.
Output signal on the analog meter rises as the self-test progresses
What are the Containment Radiation Monitors RIA-1805/1806/1807/1808.?
Analog meters but slightly different from typical analog RIA.
Each of the four has:
Analog meter
- Vertical, single-scale meter
- Only spans six decades, from 10-2 to 104 R/hr
Three-position function selector switch
- “CHECK” – Places monitor in tripped condition (Trip 2) and initiates internal self-check
- applies a voltage to the channel circuitry that corresponds to 103 R/hr, which trips the channel
- Function selector switch spring returns to “OPERATE” from “Check”
- “OPERATE” – Places monitor in service
- “TRIP ADJ” – Causes the channel output to go full-scale high
Trip 1, Trip 2, and Operate lamps/pushbuttons
RIA-1805/1806/1807/1808 Trip 1, Trip 2, and Operate lamps/pushbuttons do what?
Containment Radiation Monitors RIA-1805/1806/1807/1808 lamps/pushbuttons:
Operate (Green)
- Lit = monitor is in service.
- Not lit = may have failed low
Trip 1 (Alert – Yellow)
- Lit - met or exceeded alert setpoint of 1 R/hr
Trip 2 (High – Red)
- Lit - met or exceeded alert setpoint of 10 R/hr
- Trip 2 bistable feeds the 2 of 4 Containment High Radiation Logic
What are Containment Refueling Monitors RIA-2316/2317?
Containment Refueling Monitors RIA-2316/2317
- Energized and calibrated prior to starting core alterations.
- Removed and stored after.
- Provide inputs to the Containment Isolation logic during refueling operations
- Each monitor has a key switch located on the back of Panel C-11.
- Key switch is in the “IN” position, the associated monitor inputs to a 1/2 high alarm logic to initiate containment isolation.
- Setpoint is 80 mR/hr above background.
What are the controls/indications for the typical Digital ARM Channel?
Typical Digital ARM Channel
On-Off pushbutton
- Simply turns on/off - there are alarms
Large green LED digital display
- Displays is in scientific notation X.XXEN
- “EEEEE” displayed along with Range light lit if High out of range
- “0.00E0” displayed along with Range light lit if low out of range
Horizontal LED bar graph
- No alarm state - indication is in Green
- Warn alarm state - indication is Amber
- High alarm state - indication is Red
Four function pushbuttons
Four alarm LEDs
What is the function of the pushbutton controls for the typical Digital ARM Channel?
Typical Digital Area Radiation Monitor Pushbutton Controls
HIGH
- Press to display high alarm setpoint
WARN
- Press to display warn alarm setpoint
ALARM ACK
- Press to clear the alarm, if below setpoint
- Functions the same as the Reset button on an analog ratemeter
CHECK SOURCE
- Opens window/moves slug to expose detecting element to source.
What are the digital area radiation monitor alarm lights?
Digital AR Alarm Lights
High
Warn
Fail
- Illuminates when the ratemeter circuitry senses a channel failure
- Five minutes of zero counts from the channel detector
- Accompanied by an error code displayed on the digital display in the format, “EXXXX,” where the Xs are numerals.
- Error codes should be recorded and reported to I&C on a Work Request.
Range
- Illuminates when the measured radiation field is either out-of-range high or out-of-range low.
The CHR signal does what?
Initiated by 2 of 4 on RIA-1805, 1806, 1807, 1808
Initiated by 1 of 2 on RIA-2316, 2317
- Actuates Containment Isolation
- Trips Air Room Purge Fan V-46.
- Actuates Control Room HVAC Emergency System (Trains A and B)
- Disables automatic operation of Safeguards Rooms Sump Pumps (P-72A, 72B, 73A, 73B)
Actuates Control Room alarm EK-1363, “CONTAINMENT HI RADIATION” only when initiated by RIA-1805/1806/1807/1808.
What does RIA-5710, Penetration Fan Room Monitor, do?
RIA-5710, Penetration Fan Room Monitor
- Setpoint: 4 mR/hr
- Trips Penetration Room Supply and Exhaust Fans V-78 and V-79
- Closes dampers PO-8035 and PO-8036