Surface Contamination Monitors - doe-std-1128-98

DOE-STD-1128-98

ANSI N13.1 (ANSI, 1969a) provides detailed guidance on sampling

methods. One criterion that relates to CAMs is that air sample lines

between air inlet and filter media are to be eliminated where possible;

where not possible, they are to be designed to meet the sampling criteria

contained in the standard (e.g., short lines, proper sampling rate, smooth

bends). The use of Tygon tubing as sample lines before the collection

filter should be minimized or eliminated. Air in-leakage from

surrounding areas can be a problem when using sampling lines. Testing

for air in-leakage shall be performed at least annually or when seals or

"O" rings are replaced.

Surface Contamination Monitors. Surface contamination monitors

include hand and/or shoe counters and instruments (or probes) with

sufficient flexibility to survey pieces of equipment, including exterior

clothing. ANSI N317 (ANSI, 1980a) states that these instruments shall

have an audible alarm, a frequency that is proportional to the count rate,

or a preselectable trip setting, and that upon reaching that level shall

activate an audible or visible alarm or both. These instruments should be

calibrated according to the requirements in ANSI N323 (ANSI, 1997b)

and be equipped with a traceable check source. Fixed instruments should

be powered by alternating current (AC) and provided with an emergency

power source.

Photon and Neutron Area Monitors. Photon and neutron area monitors

measure the intensity of photon and neutron radiation in areas where

significant quantities of plutonium are stored and/or handled. ANSI

N317 (ANSI, 1980a) states that these monitors shall have a preselectable

trip setting with audible annunciators, shall provide electronic signals for

remote alarms if they are used as alarming devices, and shall be equipped

with a visual meter or digital readout. All neutron and photon area

monitors should be AC-powered and all critical monitors should be

provided with an emergency power source. Many of the requirements

that apply to portable survey instruments, as stated in ANSI N317 may

also apply to this type of instrumentation. Calibrations should be

performed according to the requirements in ANSI N323 (ANSI, 1997b).

3.5.2.3

Performance Criteria for Emergency Instrumentation

Meeting the criteria for criticality accident alarm systems, fixed nuclear

accident dosimeters, and other emergency instrumentation is essential.

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