The licensee shall establish and submit for department
approval a bioassay program used to evaluate internal doses. At a minimum an
acceptable program shall include the following action levels for organ uptakes,
corresponding actions taken if these levels are exceeded, frequency of
measurement and maintenance of records.
(1) Routine bioassay is required when an
individual handles in open form unsealed quantities of radioactive iodine that
exceed those shown in the table 1 below. The quantities shown apply to both the
quantity handled at any one time or integrated as the total amount of activity
introduced into a process by an employee over any 3-month period.
|
TABLE 1
|
|
I-125 or I-131 Activity Handled in
Unsealed Form Requiring Bioassay
|
|
Type of Operation
|
Volatile or Dispersible
|
Bound to Nonvolatile Agent
|
|
Processes in open room or bench, with possible escape
of iodine from process vessels
|
1.0 mCi (37 MBq)
|
1.0 mCi (37 MBq)
|
|
Processes with possible escape of iodine carried out
within a fume hood of adequate design, face velocity, and performance
reliability
|
1.0 mCi (37 MBq)
|
10.0 mCi (370 MBq)
|
|
Processed carried out within glove boxes, ordinarily
closed, but with possible release of iodine from process and occasional
exposure to contaminated box and box leakage
|
10.0 mCi (370 MBq)
|
100.0 mCi (3700 MBq)
|
(a) A bioassay
shall be taken within 72 hours of initial use of radioiodine and every 2 weeks
thereafter. When radioiodine use is on an infrequent basis (less than every 2
weeks), a bioassay shall be taken within 10 days of the last day of
use.
(b) If the thyroid burden at
the time of measurement exceeds 0.12 microcurie (4.44 KBq) of iodine 125 or
0.04 microcurie (1.48 KBq) of iodine 131, the following actions shall be taken:
1. An investigation of the operations
involved, including air and other facility surveys, shall be carried out to
determine the cause(s),
2.
Corrective actions that will eliminate or lower the potential for further
exposures shall be implemented,
3.
A repeat bioassay shall be taken within 2 weeks of the previous measurement and
shall be evaluated within 24 hours after the measurement in order to confirm
the presence of internal radioiodines; and,
4. Notification reports must be provided as
required by Rules
64E-5.345 and
64E-5.347, F.A.C., or as
required by conditions of the license; and,
(c) A record of each bioassay shall be
maintained for inspection by the department in an auditable form for 3 years
and shall include the date of the bioassay, the name of the individual, and the
thyroid burden at the time of the measurement.
(2) Routine bioassay is required when an
individual handles in open form unsealed quantities of tritium that exceed
those shown in table 2, below. The quantities shown apply to both the quantity
handled at any one time or integrated as the total amount of activity
introduced into a process by an employee over a 1-month period.
|
TABLE 2
|
|
Tritium Activity Handled in Levels or
Concentrations Requiring Bioassay
|
|
Type of Operation
|
HTO and Other Tritiated Compounds (Including
Nucleotide Precursors)
|
Tritium (HT or T)
Gas in Sealed Process Vessels
|
|
Processes in open room or bench with possible escape
of tritium from process vessels.
|
0.1 Ci ( 3.70 GBq)
|
100 Ci (3.7 TBq)
|
|
Processes with possible escape of tritium carried out
within a fume hood of adequate design, face velocity, and performance
reliability.
|
1 Ci (37 GBq)
|
1, 000 Ci (37 TBq)
|
|
Processes carried out within glove boxes that are
ordinarily closed but with possible release of tritium from process vessels and
occasional exposure to contaminated box and leakage.
|
10 Ci (370 GBq)
|
10, 000 Ci (370 TBq)
|
(a) A bioassay
shall be taken within 72 hours of initial use of tritium and every 2 weeks
thereafter. When work with tritium is on an infrequent basis (less frequent
than every 2 weeks), a bioassay shall be taken within 10 days of the last day
of use.
(b) If the urinary tritium
concentration exceed 5 microcuries (185 KBq) per liter at the time of the
measurement the following actions shall be taken:
1. An investigation of the operations
involved, including air and other facility surveys, shall be carried out to
determine the cause(s),
2.
Corrective actions that will eliminate or lower the potential for further
exposures shall be implemented,
3.
A repeat bioassay shall be taken within 1 week of the previous measurement and
shall be evaluated within 1 week after the measurement. Internal dose
commitments shall be estimated using at least two bioassays and other survey
data, including the probable times of intake of tritium; and,
4. Notification reports must be provided as
required by Rules
64E-5.345 and
64E-5.347, F.A.C., or as
required by conditions of the license; and,
(c) A record of each bioassay shall be
maintained for inspection by the department in an auditable form for 3 years
and shall include the date of the bioassay, the name of the patient, and the
urinary tritium concentration at the time of the
measurement.
