Radiation survey meter

Neutron radiation survey meter. General neutron survey. 

Radiation survey meter with telescopic extension. General radiation survey. 

High sensitivity underwater radiation survey meter covering the range from 0.1 mr/hour to 30000 rad.hour. Spent fuel measurements. Also for unattended monitoring (if coupled to computer). 

Because it cannot count at high rates without losses, the Geiger counter is now obsolete in diffractometry. It is still used in some radiation survey meters. 

To meet ERDA (formerly AEC) license requirements, the activity of each sample received was monitored with a radiation survey meter, and the personnel involved were supplied with radiation dosimeters. An excellent discussion of radiation safety and licensing requirements in handling reactor-activated petroleum products is available (49). 

Which of the following is not one of the typical pre-operational checks before using a radiation survey meter ... 

Radiation Saturation A phenomenon in which a survey meter s capability to measure radiation levels is overwhelmed, causing the meter to incorrectly read zero . 

Roentgen (R) The unit of radiation exposure in the air units for quantities of X-ray or gamma radiation measured by detection and survey meters. Named after Wilhelm Roentgen, German scientist who discovered X-rays in 1895. 

Health Physics Laboratory. The health physics laboratory is located at the entrance to the radiation sources controlled area (Figure 2). From this laboratory the access to the radiation sources area is monitored and controlled. The health physics laboratory is equipped with portable beta, gamma, and neutron survey meters of various designs and ranges to facilitate the area monitoring, air monitors for airborne contamination, and anticontamination equipment. It is equipped with monitors and alarms for the area radiation detectors, pool water level indicators, and access doors. It also has ready access to the counting equipment of the radiochemistry laboratory. 

When lead bricks or concrete blocks are used as shielding materials, shielding must be done as near radiation sources as possible and the shielding effect must be confirmed with a survey meter. Care must be taken in regard to leaking and scattering rays through clearances between piled bricks and blocks. A lead container is usually used to carry radioactive materials. 

Dosimeters are used in conjunction with survey meters to monitor the amount of radiation that personnel are exposed to over a given period of time. There are two types of civil defense dosimeters with different monitoring scales. The CD V-138 is used for monitoring relatively low levels of exposure and has a minimum-scale reading of 200 mR. The CD V-742 has a range up to 200 R (200,000 mR) and is used for high levels of personnel exposure. Both meters should be worn by responders to ensure proper protection. 

Measurement of ionizing radiation. Standard survey meters are of two types Geiger counters and ionization chambers. To accurately measure radiation, they must be calibrated by a known... 

This saturation collection current finds two important applications - measurement of high radiation fields without paralysis and measurement of intensities of extended photon emitters. A GM detector (see next section) is a useful survey meter for modest levels of radiation, but in high radiation fields a GM detector becomes paralyzed. Ionization chambers based on continuous current do not have this deficiency and even benefit from the more robust current. 

Portable survey meters Detect radiation emanating from a point source Geiger-Muller counter Ionization chamber Solid scintillation... 

A frisker type hand held radiation meter may be used to survey low levels of contamination and may be used to demonstrate the use of a portal monitor. If a whole body counter is available, student monitoring can be a useful experiment. It can be performed with and without radioactive materials concealed in or on clothing (e.g., lantern mantels, or other available unlicensed materials.) The same can be performed with hand held survey meters, perhaps allowing one group to hide sources and another group to find them. 

What meter would you choose to do a general radiation survey of the reactor laboratory while the reactor was shut down ... 

A radiation survey of an area reveals a general radiation reading of 1 mrem/hr. There is, however, a small source which results in 10 mrem/hr in one (1) meter. Which ONE of the following defines the posting requirements for the area in accordance with 10 CFR 20 ... 

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. 

Radiation Saturation A phenomenon in which a survey meter s capability to measure radiation levels is overwhelmed. causing the meter to incorrectly read zero". Ratfiatlon Sterilization Use of radiation to cause a plant or animal to become incapable of reproduction the use of radiation to kill all forms of life, especially bacteria, in food and surgical sumres. 

Portable radiation monitors. Portable measuring instruments include gamma survey meters and neutron dose equivalent meters. The use of portable instruments is helpful, provided that the place and time of measurements are specified and recorded. 

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.

It is important to realize that if the survey meter is not functioning properly, we might be harmed by radiation or loose ore fields. The problem is that sometimes the fault develops very slowly, without dramatic signs. The repair staff and the user should know how to check the performance of the survey meter to overcome the hazards to health and property. 

All survey meters have an ionizing radiation detector and circuits to convert the detector-sIgna1-carried information into dose-rate information and a display unit. The survey meters are battery-operated, portable units. With a few exceptions, they contain DC/DC converters for the detector supply, as well as for the low voltage. 

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