Radiation Surveying instruments

NRC. 1998b. Minimum detectable concentrations with typical radiation survey instruments for various contaminants and field conditions. Washington, DC Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission. NUREG/CR-1507. 

Demonstrating use of radiation survey instruments and instruments for screening chemical agents... 

E. Detection of Suspected NBC Agents. It is not always evident when biological, chemical, or radiological weapons have been used. For example, several days will pass between the release of anthrax and the appearance of the first symptom. One method to detect the use of NBC agents before the appearance of symptoms is to sample the environment and troops. Personnel monitoring using radiation survey instruments should be done if radioactive contamination is... 

Individuals within the laboratory should, as in any other emergency, evacuate the area following routes that would reduce their risks. Any location within the facility should have two evacuation routes so that one, at least, should be relatively safe.The storage location ofportable radiation survey instruments should be near the entrance to the facility oralong the evacuation route deemed most likely to be safe in a radiation-related emergency. 

A radiation survey instrument was used to measure an irradiated experiment. The results were 100 mrem/hr with the window open and 60 mrem/hr with the window closed. What was the beta dose rate ... 

RADIATION SURVEYS, INSTRUMENT CALIBRATION AND RADIATION WORK PERMITS... 

It is necessary to choose monitoring equipment with care, since not all equipment is equally efficient at detecting all types of radiation. There are three basic types of portable radiation surveying instruments (Figure 13.3). 

Piltingsrud HV, Farr RL. 1978. A beta-alpha-gamma x-radiation (bag-x) detection probe for use with a plutonium-americium survey instrument. Health Phys 34 177-184. 

Calibration of Survey Instruments Used in Radiation Protec-... 

SC 46-4 Calibration of Survey Instrumentation SC 46-5 Maintaining Radiation Protection Records SC 46-6 Radiation Protection for Medical and Allied Health Personnel SC 46-7 Emergency Planning... 

Calibration of Survey Instruments Used in Radiation Protection for the Assessment of Ionizing Radiation Fields and Radioactive Surface Contamination (1991)... 

NCRP. 1991. National Council on Radiation Protection and Measurements. Calibration of survey instruments used in radiation protection for the assessment of ionizing radiation fields and radioactive surface contamination. NCRP Report No. 112. Bethesda MD. 

In addition to survey instrumentation, the radiochemical forensic lab requires basic radiationcounting support in order to monitor the progress of certain chemical separations. For example, the performance of a methanolic nitric acid separation of Am and Cm on an anion-exchange column is not always reproducible. In operation, the column eluent is collected as a sequence of small samples in a number of glass centrifuge cones. Americium, which emits Y radiation in its decay, follows curium off the column, and is located in the eluent stream with the aid of a laboratory radiation counter. 

Under any emergency conditions for which the locations of the potential or actual releases can be identified, instrumental measurements should be used to define as well as possible the source related radiation fields associated with the emergency. Under most conditions this would amount to the use of beta-gamma survey instruments. However, it should be ensured that the types of instruments available for measurement purposes are suitable. For example, if the material released might consist of tritium or plutonium, then the usual beta-gamma survey instruments are not useful, and special instruments and/or monitoring techniques should be used. 

Use of individual survey instruments used in reactor lab-function, range, type of radiation detected, conversion to dose survey methods to be used in Reactor Laboratory. 

Match the best Radiation Survey or detection instrument in the right column to the measurement in the left column by writing in the survey instrument number in the blank. 

As a minimum, radiation surveys should be performed when x-ray generating equipment is installed, modified, or moved. These surveys are typically performed with a Geiger-Muller (G-M) coimter or other sensitive rate meter with a fast response. The probe of the survey instrument is moved in a zigzag pattern across all surfaces of the tool. Cabinet seams, windows, screw holes, and other penetrations are particularly scmtinized. As part of the survey, any interlocks on the equipment should be checked to ensure they are functioning properly. 

Records documenting the designation and location of controlled and supervised areas should be kept. Records should also be kept of radiation surveys, including the date, time, location, and the radiation levels measured, and any comments relevant to the measurements made. Records should identify the instrument(s) used and the individual performing the survey. 

Figure 13.5 Monitoring and surveying instruments. These are used to detect spills and stray radiation. Front row, from left ratemeter with low-energy gamma probe ratemeter with pancake probe for beta detection survey meter for gamma and high-energy beta area-survey meter for detecting gamma and x-ray radiation fields. Back row alpha detection probe ratemeter with scalar.

Remove the neutron source from the graphite pedestal. Note time of removal on the data sheet. Remove stringers from the pile. Check the radioactivity of the stringers and foils with a radiation safety survey instrument to insure no dangerous health conditions are prevailing. 

Evaluate the initial direet reading instrument survey data for the presenee of eombustible gases, organie and inorganie gases, partieu-lates, vapors, and ionizing radiation. 

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