required using the equations shown in Section VIII. These data are available in tabular
form from the EIC computer.
Vil.
B.
Unlock the shield plug padlock and attach the source handling tool.
C.
During calibration be watchful of personnel entering the field. Immediately, on
completion of calibration, lower the source into its shielded container.
D.
When ealibration operations have been completed remove the source handling tool, lock
the shield, place the shielded container in the bunker, and place a weatherproof cover
over the shield.
E.
Remove the rope barrier from the area and lock the storage bunker.
calibrate probe as specified in the instrument procedure manual.
Proceed to
Source Testing
All sources shall be leak tested in accordance with the current FRST Source Testing SOP 608-06 at
least every six months. A copy of the SOP is attached for reference. The source should be leak
tested whenever rust is evident on the shield or if it is difficult to return and remove the source from
the shield, or when damageto the source is suspected.
Vill.
Source Handler
Care should be used during setup of bunker source handling system to assure that source capsule does
not drag during removal from and insertion into shield. Shim or align shield and/or bearing unit to
prevent any detectable drag. Spacers on shield plug shall be installed to prevent source from
impacting on pig bottom during insertion.
Decay of dose rate listed will be as follows:
1 = Ipe{(0.693)(T))/361.2
I = Intensity at Time T
I, = Intensity at calibration date Ty
T = Months from Ty, to present date (measure to nearest 1/10 month)
Intensity values for the Enewetak cesium-137 calibration source are listed below:
Source
Intensity(mR/h @ 100 em\(I,)
100 mCi (CS-352)
10 mCi
Date(T,)
29.9
6/28/77
0.35
8/31/77
(Future Source)
1 mCi (CS-8184A)
The following equation can be used to calculate the field intensity-distance relationship:
d= 39.37 / 11/12
Where
Il
Present intensity of field in mR/h at 1 meter after correction
factor is applied.
12
Intensity of field mR/h at distance d.
Distance in inches between source and test point (2.54 em = 1 inch).
A-18-2