Earlier in this section, a quick-sort method was described using neutron
activation of sodium in the blood as an indicator of worker exposure. More
sophisticated laboratory analysis of blood samples can be performed to
obtain a more accurate estimate of worker dose, as discussed in Delafield
(1988) and Hankins (1979). The use of neutron activation of sulfur in hair
(32S(n, p)32P) is another method to estimate absorbed dose for workers
involved in a criticality accident (Petersen and Langham, 1966). The
orientation of the subject can also be determined by taking samples of hair
from the front and back of the person. Hankins (1979) described a technique
for determining neutron dose to within ±20-30% using a combination of
blood and hair activations. Their evaluation was independent of the worker's
orientation, of shielding provided by wall and equipment, and of neutron
RESPONSIBILITIES OF HEALTH PHYSICS STAFF
The health physics staff should have a basic understanding of program structure,
engineering criteria, and administrative controls as related to nuclear criticality safety as
reviewed in earlier sections of this chapter. Additionally, the health physicist's
responsibilities include emergency instrumentation and emergency response actions.
During routine operations the health physics staff's responsibilities related to
nuclear criticality safety include calibrating, repairing, and maintaining the neutron
criticality alarm detectors and nuclear accident dosimeters, and maintaining
appropriate records. The health physics staff should be knowledgeable of criticality
alarm systems, including alarm design parameters, types of detectors, detector area
coverage, alarm set-points, and basic control design. The staff should also be
familiar with plans for emergency response.
The health physics staff should maintain an adequate monitoring capability for a
nuclear criticality accident. In addition to the criticality alarm systems and the fixed
nuclear accident dosimeters discussed above, remotely operated high-range gamma
instruments, personal alarming dosimeters for engineering response/rescue teams,
neutron-monitoring instrumentation (in case of a sustained low-power critical
reaction), and an air-sampling capability for fission gases should be maintained.
Other support activities may include assisting the nuclear criticality safety engineer
or operations staff in performing radiation surveys to identify residual fissionable
materials remaining in process system or ventilation ducts.