Contamination Monitoring Flashcards
Fill in the blanks:
Using a 44-9 probe, where the background count rate is <___ CPM, scan at ~__” per second within __” of the surface.
100
2
1/2
Above which level should beta/gamma DP surveys not be taken?
300 CPM, unless in a casualty scenario)
Fill in the blanks for the uranium control system:
Using an ASP-2 probe, scan at __ to __” per second within __” to light contact, stopping at select hold points for __ seconds.
Which blank changes if in the TRU system?
1
2
1/8
5
The hold point length changes to 15 seconds
Fill in the blanks for the uranium control system:
If ≥ 1 click in ___ seconds, count for an additional __ seconds. 2 clicks in 15 seconds = <__ pCi. If ≥ 3 clicks in 15 seconds, count for an additional __ minute(s). __ clicks in in 1 minute = 50 pCi.
5
15
50
1
20
Fill in the blanks for the TRU control system:
If ≥ 1 click in __ seconds, count for an additional 30 seconds. 2 clicks in 30 seconds = <__ pCi. If ≥ 3 clicks in 15 seconds, count for an additional __ minute(s). __ clicks in in 1 minute = 20 pCi.
15
20
1
8
Why is direct frisking preferred over swipes?
DPs require less time
DPs measure both fixed and loose surface contamination
Swipes don’t provide representative samples on porous surfaces
Why are dry swipes used?
Because they are more representative of how contamination is spread by personnel brushing past these surfaces than other methods
Can personnel be surveyed for contamination by swiping? why or why not?
No! Swiping might embed rad particles into the pores of the skin
What is the basis for 100 cm2 swipe area?
Swipes tend to disintegrate when wiped over a larger area
Area gives nearly optimum efficiency for collecting and measuring contamination
Area is convenient
Standardizes surveys
How are wet swipes surveyed?
Surveyed initially when taken, and then again after they dry (in order to better asses for alpha activity)
How long are MFP/ACP swipes counted initially? U? TRU?
5 seconds
5 seconds
1 minute
Fill in the following information for U/TRU swipes after initial 5/60 second count:
U
If ≥ 1 click, count for ___ seconds.
After that, if ≥ 3 clicks, count for ___ seconds.
TRU
If 2-3 clicks, count for ___ seconds.
If 2-3 clicks again, send to ____________.
15
60
60
radiochemistry
Why are LAWs and DAWs used?
To determine that an area is free of loose surface contamination.
What are LAWs made of? How large of an area do you take LAWs? What type of contamination can LAWs not reliably detect?
Absorbent material folded into an approximately 6” x 6” square and dampened with water or other non-haz liquid. Taken in <1m2 area.
Because LAWs are dampened, they cannot be used to determine that an area is free of alpha loose surface contamination.
