Total radiation dose calculations for operations in areas where the decay rate is nonstandard can be

computed using the total dose (fallout) nomogram, the residual decay (fallout) nomogram, and the

correction factor for nonstandard decay (LOW n) and (HIGH n) nomograms, (Figures 6-9 and 6-10).

Total dose computations are made using the total dose nomogram and the same principles as for

standard decay with the following exceptions.

1.

The R1 value must always be determined for dose calculations using the appropriate

decay exponent. Using the residual radiation decay (fallout) nomogram, determine the H

+ 1 dose rate for the appropriate nonstandard decay exponent.

2.

For problems where it is desired to find a time of entry, time of stay so that a specific

total dose will not be exceeded, standard decay should be assumed. These calculations

will be approximations, since no direct method is available for finding these values for

nonstandard decay.

The true dose can be determined by multiplying the dose calculated from the total dose (fallout)

nomogram, by the correction factor (CRF) determined from the correction factor for nonstandard decay

nomograms in Figures 6-9 and 6-10.

Integrated Publishing, Inc. |