rad monitor Flashcards
Components
Scintillation Detector
Function/design
A photomultiplier tube transforms each light flash into a small pulse of electrons and then amplifies the pulse a million fold or more
Components
Scintillation detector
How many types used at TMI?
Which ones?
2
Thallium activated sodium iodine (good for gamma photons)
Beta plastic
RMS alarms
High, alert, fail interlock bypass
Bypass/reflash explain
C-?-? for each
-High (C-1-1)
o Alert (C-1-1)
o Fail (C-3-1)
o Interlock Bypass (C-2-1)
o Radiation Level and Interlock Bypass alarms will REFLASH if another one comes in after the first is acknowledged and not cleared
Components
RMS interlocks
Activated by what setpoint of respective rad monitor?
Liquid, area gamma monitors, atmospheric
Use what channels for high alarm interlocks
Activated by High alarm setpoint of respective RAD monitor
-> Use GAS channels ONLY for the high alarm interlocks
types of gas filled detectors at TMI, what regions
used for what?
ionization chambers (region 2) (when dose rate info is desired
Geiger-Mueller (region 5) (determine presence of radiation)
Gas filled detector
region 3
number of ions collected is a multiple of the number originally created, multiplication factor increases with what? what is that called?
multiplication factor increasing with voltage (gas amplification, proportional counter)
RMS interlocks
if detector voltage Fails (no voltage to the rad monitor itself, but the voltage to a detector inside the rad monitor) and rate and amplifier are still funciton, the interlock is still functional? if power to the rad monitor FAILS, interlocks will actuate?
yes
RMS interlocks
on restoration of power needle pegs what when reset? interlocks placed in what position procedurally before power restoration?
on restoration power needle pegs high when reset
interlocks placed in defeat before power restoration
detectors
RM-G-9
FH Bridge (fuel handling bldg)
interlocks, can they be defeated?
what does it do?
interlocks can be defeated
1.) trips AH-E-10
2.) Closes AH-D-120/121/122
detectors
RM-G-16
A OTSG sample 305’ turb bldg
can interlocks be defeated?
what does it do?
interlocks can be defeated
closes CA-V-4A/5A
detectors
RM-G-17
B OTSG sample 305’ turb bldg
can the interlock be defeated?
what does it do?
interlocks can be defeated
closes CA-V-4B/5B
detector
RM-G-18
RCS sample 305’ aux
can interlocks be defeated?
what does it do?
interlocks can be defeated
Closes CA-V-1/2/3/13
detectors
RM-G-20
RCDT outlet 305’ aux
can interlocks be defeated?
what does it do?
interlocks can be defeated
closes WEDL-V-303/304
Closes WDG-V-3/4
power supplies
detectors powered form what?
vital buses
power supplies
sample pumps powered from where?
ES MCCs
interlocks
actuated by which alarm on which channels?
actuated by ‘High alarm’ on Gaseous channels only
flow path
isokinetic nozzle flow path
which RM-A inlet doesn’t have one?
isokinetic nozzle -> P -> I -> G -> sample pump -> return
RM-A-2 inlet
Map-5 samplers (3)
which ones and their names
RM-A-8 aux/FH exhaust
RM-A-9 RB purge Exhaust
RM-A-5/15 condensor off gas
map-5 samplers
Start on which alarm or manually from where?
start on GAs high alarm or manually form control room
map-5 samplers
after solenoid valves open, sample pump starts except for which one because it uses what?
how must pump be shut off?
composite sampling of iodine for what?
RM-A-5, it uses vacuum pump DP
pumps must be shut off locally
composite sampling of iodine for accurate offsite dose calculations
RM-A-1 control room
what interlock does it have and what does it do if reached?
Gas high alarm
Trips AH-E-17A/B, 20A/B, 21,26,93A/B, 94A/B,95A/B
closes AH-D-28/617
RM-A-2 tx bldg atmosphere
non-RMS interlocks (2) what are they and what do they do?
CM-V-1/2 sample pump interlocks
-> if CM-V-1 and/or CM-V-2 goes closed RM-A-2 pump goes off
-> pump will NOT start unloss both CM-V-1/2 are OPEN
ESAS isolation of RB sample line
-> ESAS signal closes CM-V-1/2/3/4
RM-A-4 fuel handling bldg
interlocks (1) and what does that do?
Gas High Alarm
trips AH-E-10
closes AH-D-120/121/122
RM-A-5 Lo condensor off-gas monitor
interlocks (1) and what does it do?
Gas High alarm
starts Map-5 sampler
RM-A-6 aux bldg
interlocks (1) and what does it do?
Gas High alarm
trips AH-E-11
RM-A-7 waste gas disposal effluent
interlocks (1) what does it do?
Gas High Alarm
Closes WDG-V-47
RM-A-8 Aux/FH Bldg Combined Exhaust
Interlocks (1) what does it do?
**Gas High Alarm **
Trips AH-E-10/11
Closes WDG-V-47
Starts MAP-5 sampler
RM-A-9 RX bldg purge exhaust
interlocks (1) what does it do?
Gas High Alarm
Closes AH-V-1A/B/C/D
Closes WDL-V-534/535
Starts MAP-5 sampler
Rm-A-14 ESF
interlocks (1) what does it do?
Gas High alarm
switches to accident range jfilters and bypasses Rm-A-14G-Lo
RM-A-15 Condenser Offgas Backup
interlocks (1) what does it do?
starts Map-5 sampler
RM-L-1 Hi RCS letdown
interlocks (1) what does it do?
fuel failure will not be detected until it gets to the monitor after how long of a delay?
Closes Mu-V-2A/B which isolates letdown
30-60 mins
RM-L-6 Plant Radioactive Waste Discharge
interlock does what?
closes WDL-V-257
RM-L-7 plant water discharge
interlock does what?
closes WDL-V-257
RM-L-12 IWTS/IWFS Effluent
what happens on interlock?
Trips IW-P-16/17/18 (IWTS effluent pumps)
Trips IW-P-29/30 (IWFS effluent)
Closes IW-V-73 (IWTS release), Closes IW-V-279 (IWFS release)
Limits and Precautions
when testing the detector high radiation alarm or priot to removing a monitor from service, ensure what?
ensure that all interlock switches are in the defeat position to prevent inadvertently tripping interlocks
limits and precautions
ensure T.S. requirements are satisfied prior to doing what?
Main annunciator panel alarm C-2-1, rad mon interlock bypass, will do what when any radiation monitor interlock switch is placed in the what position and another radiation monitor is already in what?
will re-flash when any rad mon interlock switch is placed in the defeat position and another rad monitor is already in defeat
Limits and precautions
When the reactor is critical and above 2% power and the RB rad monitor (RM-A-2) becomes inoperable, a sample of the RB atm will be taken how often?
every 8 hours
limits and precautions
reading alarm setpoins from the meter face by pressing the alarm pushbutton does NOT give an accurate indicaiton of actual setpoint. this feature is not calibrated and should not be relied upon for accurate setpoint information
true
tech specs (area gamma monitors)
post accident montioring 3.5.5
with the number of OPERABLE channels less than required by the minimum channels operable requirements:
either restore the inoperable channel to operable status within 7 days of the event (highlighted) OR
submit a special report within 30 days (not highlighted)
tech specs (atmospheric monitors)
when reactor is critical and above 2% power, 2 reactor coolant leak detector systems of different operating principles shall be in operation for the RB with 1 of 2 systems sensitive to radioactivity. the systems sensitive to radioactivity may be out of servce for no more than how much time provided a sample is taken of the RB atm every how long and anaylyzed for radioactivity and 2 other means are available to detect leakage.
the 1 of 2 system for radioactivity sensitivity may be out of service for 72 hours provided sample taken of RB atm every 8 hours is analyzed for radioactivity and 2 other means are available to detect leakage.
lmits and precautions: ODCM
RM-A-5with number of channels operable less than required by the min channels operable req, effleunt releases via this pathway may continue for how long?
up to 14 days
limits and precautions: ODCM
RM-A-5
If the primary-to-secondary leak rate was unstable, or was indicating an increasing trend at the initial time when there was no operable channel of the Condenser Vent System Low Range Noble Gas Activity Monitor, analyze grab samples of the reactor coolant system and Condenser OffGas once every how long?
every 4 hours
precautions and limitations: ODCM
RM-A-7 gas release
With the number of channels OPERABLE less than required by the Minimum Channels OPERABLE requirement, the contents of the tank may be released to the environment provided that prior to initiating the release, these three things apply:
- At least two independent samples of the tank’s contents are analyzed in accordance with Table 3.2-2, Item A, and
- At least two technically qualified members of the Unit staff independently verify the release rate calculations and verify the discharge valve lineup.
- The TMI Plant Manager shall approve each release. Otherwise, suspend release of radioactive effluent via this pathway.
precautions and limitations:
RM-A-4/RM-A-6/RM-A-8/RM-A-9/ALC-RMI-18
particulate/iodine
With the number of channels OPERABLE less than required by the Minimum Channels OPERABLE requirement, effluent releases via this pathway may continue provided that:
within four hours after the channel has been declared inoperable, samples are continuously collected with auxiliary sampling equipment.
precautions and limitations:
GAS
With the number of channels OPERABLE less than required by the Minimum Channels OPERABLE requirement, effluent releases via this pathway may continue provided:
grab samples are taken at least once per 12 hours and the initial samples are analyzed for gross activity (gamma scan) within 24 hours after the channel has been declared inoperable.
precautions and limitations:
RM-A-14
With the number of channels OPERABLE less than required by the Minimum Channels OPERABLE requirement, effluent releases via this pathway may continue provided:
grab samples are taken at least once per 12 hours and the initial samples are analyzed for gross activity (gamma scan) within 24 hours after the channel has been declared inoperable.
precautions and limitations:
RM-A-14
With the number of channels OPERABLE less than required by the Minimum Channels OPERABLE requirement
either restore the inoperable channel to OPERABLE status within 7 days
precautions and limitations:
WHP-RIT-1/RLM-RM-1
With the number of channels OPERABLE less than required by the Minimum Channels OPERABLE requirement, effluent releases via this pathway may continue provided that :
within four hours after the channel has been declared inoperable, samples are continuously collected with auxiliary sampling equipment.
precautions and limitations: liquid monitors
RM-L-C (WECSTs)
With the number of channels OPERABLE less than required by the Minimum Channels OPERABLE requirement:
effluent releases may continue, provided that prior to initiating a release:
- At least two independent samples are analyzed in accordance with Surveillances 3.2.1.1.1 and 3.2.1.1.2 and;
- At least two technically qualified members of the Unit staff independently verify the release rate calculations and verify the discharge valve lineup.
- The TMI Plant Manager shall approve each release. Otherwise, suspend release of radioactive effluents via this pathway.
precautions and limitations:
RM-L-12 (IWTS)
With the number of channels OPERABLE less than required by the Minimum Channels OPERABLE requirement:
effluent releases via this pathway may commence or continue provided that grab samples are collected and analyzed for gross radioactivity (beta or gamma) at a limit of detection of at least 1x10-7 microcuries/ml, prior to initiating a release and at least once per 12 hours during release.
RM-L-12 IWTS/FS Effluent has local indication ONLY and does what on high alarm?
Closes IW-V-73 release valve on high alarm
when restoring rad monitors to service, the what switch is selected to prevent auto actuation of interlocks?
defeat switch
RM-G9 and RM-A-4 and RM-A-8
which ones are interlocked with AH-E-10 and FHB dampers, which one is just the fan
RM-G-9 and RM-A-4 ah-e-10 and FHB dampers
RM-A-8 only fan
RM-A-9
if moving fuel and accident occurs that causes RM-A-9 to go HIGH, the RB purge valves (which ones) will stay in what position? they usually go to what position but it’s different in this situation why?
also basis
AH-V1a/b/c/d will stay open. usually go closed on high alarm but in defeat during fuel moves. to ensure RB pressurization doesn’t occur to prevent BWST gravity drain to RCS. action is to suspend fuel move and evacuate RB.
if RM-A-9 is inoperable, dicontinue what? if you can’t commence what?
discontinue purge and isolate AH-V-1’s within 8 hours per T.S 3.5-1. if unable to isolate any of the AH-V-1’s commence shutdown since t.s. not met
RM-L-1
what’s the time delay?
due to what?
first indication of fuel failure comes from what?
30-60 min time delay, due to letdown transport time.
first indication of fuel failure comes from RM-A-5/15
RM-A-2
make up flow to RM-A-2 provided from RB to prevent what?
when doing work on RM-A-2, do what to prevent breaking containment?
1.) prevent pressurization of building and contaminating IB
2.) shutdown pump and isolate CM-V1/4 to prevent breaking containment integrity
