ALARA Guidelines - STD-1128-98master0115

DOE-STD-1128-98

Guide of Good Practices for Occupational Radiological Protection in Plutonium Facilities

the field, the phoswich detector has a detection limit of <1 nCi/g. The ZnS scintillation

detector had a detection limit of 25 pCi/g for gross alpha counting. Laboratory-based

systems include active and passive gamma-ray spectroscopy, passive neutron detection, and

pulsed portable neutron generator interrogation.

During the decommissioning of a mixed-oxide fuel fabrication facility, West et al. (1991)

used a nondestructive assay system to provide criticality safety monitoring, track the

plutonium inventory, provide measurement of decontamination effectiveness, and provide

quantitative characterization/assay of the waste. The system consisted of an integrated set of

two passive neutron networks, two pulsed active neutron units, a high-resolution gamma

spectrometer [high-purity germanium (HPGe)], and a neutron-coincidence counting unit.

Waste determined to be less than 10 nCi/g was certified as class A low-level waste (LLW).

4.2.7 ALARA Guidelines

Contamination levels should be maintained ALARA to minimize the potential for the spread

of contamination and to reduce the protective measures and equipment required. Control of

radioactive material at the source and prevention of the generation of contamination are

more effective and less costly than remediation.

4.3

PERSONNEL CONTAMINATION CONTROL

As described earlier, the purpose of contamination control is to prevent the ingestion or inhalation

of plutonium by workers. This is primarily achieved by the engineered barriers discussed

previously, containment, confinement, and ventilation control. Only if the primary controls fail or

if there is a potential for personnel contamination during an activity are administrative controls such

as protective clothing and respirators advisable.

4.3.1 Monitoring Philosophy

Monitoring the worker is necessary, not only to ensure that a potential intake is detected

promptly and that the resulting internal dose is assessed, but to confirm the integrity of the

engineered containment system and ensure the effectiveness of the overall radiation

protection program.

There are several types of worker monitoring, some during and immediately following work

with radioactive material and some scheduled for a later time at a preset frequency. This

section addresses only methods of monitoring the worker at the workstation. Other methods

are discussed in the section that deals with internal and external exposure controls.

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