RPT 113Instructional Resources
Module 3: Monitor Dose Rates Using G.M. Detectors
Table of Contents:
Resources Key......
Module Readings and Homework......
Primary Scenario “Perform Dose Rate Survey Under Reactor Vessel Head”......
Transfer Scenario “Remotely Measure Radiation Levels at a Research Reactor”......
Module Assessment Items
Primary Scenario “Perform Dose Rate Survey Under Reactor Vessel Head”......
Suggested Labs......
ACAD References......
Resources Key
This refers to: / This reference:ACAD / National Academy for Nuclear Training, Uniform Curriculum Guide for Nuclear Power Plant Technician, Maintenance, and Nonlicensed Operations Personnel Associate Degree Programs, ACAD 08-006.
DOE-SG / Office of Environmental, Safety and Health: Radiological Control Technician Training Site Academic Training Study Guide Phase I, Project Number TRNG-0003
Available at: File is located under the Docs/General Curriculum/DOE materials folder.
G. / Gollnick, D. (2006). Basic Radiation Protection Technology, 5th Ed. Pacific Radiation Corporation, Altadena, CA.
Spectrum / Spectrum Spectroscopy Techniques Lab Manual (Instructors and Student Versions)
Supl. Lab / Supplemental Lab Manual (instructors and Student Versions)
Module Readings and Homework
Primary Scenario “Perform Dose Rate Survey Under Reactor Vessel Head”
Core Concept: Detector EfficiencyHomework (end of chapter)
Readings / Calculation Items / Non-calculation Items
G., Chap. 7, # 243-244 / N/A / N/A
Core Concept: Dead time losses
Homework (end of chapter)
Readings / Calculation Items / Non-calculation Items
G., Chap. 7, # 264-265 / G., Chap. 12, #32 / G., Chap. 7, # 10, S-2
Core Concept: G.M. tube based telepole detector design and operation
Homework (end of chapter)
Readings / Calculation Items / Non-calculation Items
DOE-SG-Mod. 2.16-14-2.16-16 / N/A / DOE-SG-Mod. 2.16.03
Transfer Scenario “Remotely Measure Radiation Levels at a Research Reactor”
Refer to readings and homework for primary scenario above.
Module Assessment Items
Note: If instructors wish to increase the difficulty of any item,then we suggest you use it as the basis for an in-class discussion, and / or require students to write an explanation for why a particular choice is correct.
Primary Scenario “Perform Dose Rate Survey Under Reactor Vessel Head”
1. (Prediction) If the size of a G.M. detector (volume) is increased, what happens to the geometric and intrinsic efficiencies of the detector?
A.) They both increase. (Correct)
B.) The geometric efficiency increases and the intrinsic efficiency decreases.
C.) They both decrease.
D.) The geometric efficiency decreases and the intrinsic efficiency increases.
2. (Prediction) When contrasting the dead time correction for a G.M. detector (300 µsec dead time) with a proportional counter (1 µsec dead time), which statement below is correct?
A.) The G.M. tube detector will have the larger error in the observed count rate. (Correct)
B.) The proportional counter detector will have no dead time losses.
C.) Both detector systems will have similar dead time losses.
D.) The percentage of lost counts is less for the G.M. tube detector.
3. (Explanation) Which of the explanations below describe why the high range detector in the G.M. Telepole instrument is reduced in size?
A.) To increase the detector's overall efficiency
B.) To prevent saturation (Correct)
C.) To increase the dead time of the detector
D.) To reduce the physical size and weight of the detector probe
4. (Explanation) Which of the statements below is correct based on the effect of dead time on G.M. detector response?
A.) At high exposure rates the dead time losses cause the detector response to show higher than actual exposure rates
B.) At low exposure rates the dead time losses cause the detector response to show lower than actual exposure rates
C.) At high exposure rates the dead time losses cause the detector response to show lower than actual exposure rates (Correct)
D.) At low exposure rates the dead time losses cause the detector response to show higher than actual exposure rates
5. (Explanation) Which of the following explanations best describe why a G.M. detector is the best detector type for the Telepole instrument?
A.) An ionization chamber is too sensitive to radiation and doesn’t work well in high radiation fields.
B.) The G.M. detector inside the telepole will easily measure alpha radiation, which causes most of the dose.
C.) The G.M. detector’s has a small dead time which makes its measurement more accurate.
D.) An ionization chamber is sensitive to electronic interference from radio signals and magnetic fields (Correct)
Suggested Labs
Spectrum Lab #4 - Resolving Time, page 30
ACAD References
1.1.8 Radiation Protection and Detection
- Explain the principles and operation of radiation detection and monitors including the following:
Module Monitor Dose Rates Using G.M. Detectors
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