An Applications Guide to Pedestrian Snm Monitors

By Fehlau, Paul E.

Book Id: WPLBN0000142983
Format Type: PDF eBook
File Size: 4.0 MB
Reproduction Date: 2008

Title:	An Applications Guide to Pedestrian Snm Monitors
Author:	Fehlau, Paul E.
Volume:
Language:	English
Subject:	Government publications, Legislation., Government Printing Office (U.S.)
Collections:	Government Library Collection
Historic Publication Date:
Publisher:	Government Printing Office


Citation APA MLA Chicago Fehlau, P. E. (n.d.). An Applications Guide to Pedestrian Snm Monitors. Retrieved from http://gutenberg.cc/

Excerpt
Introduction: Pedestrian special nuclear material (SNM) monitors offer a rapid, effective means to search for SNM as an individual departs a material-access or protected area. The SNM monitors sense gamma radiation emitted by nuclear materials, which is a more specific clue to the presence of the material than is its visual or tactile appearance. Best performance is obtained from well-designed monitors when the monitors are situated away from interfering radiation fields, when they are properly calibrated and adjusted, and when the monitors are periodically tested to be sure that they are in a good state of repair. The purpose of this applications guide is to make you familiar with the SNM pedestrian monitors that are applied at DOE contractor facilities. Our goal is to familiarize You with the monitors and their operation as well as to tell you h;w the monitors should be maintained once they have been input into use. We hope to make you aware of the monitors’ limitations as well as their strong points. Our task is not as simple as we would like it to be because many different people are involved...

Table of Contents
CONTENTS INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Partl. AN OVERVIEW OF PEDESTRIAN SNMMONITORING . . . . . . . . . . . . . . 2 I. II. III. IV. v. VI. VII. PEDESTRIANSNMMONITORS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 GAMMA-RAYMONITORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 FACTORSTHATAFFECTPEDESTRIANSNMMONITORPERFORMANCE. . . 4 A. MonitoringStatistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 B. SNMRadiationIntensity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 C. MonitoringTime s...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 EXAMPLESOFSNMMONITORMASSDETECTIONSENSITIVITY. . . . . . . . 8 APPLYING AUTOMATIC SNMPEDESTRIAN MONITOR TECHNOLOGY . . . 8 A. Preplanning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 B. Climate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 C. Protecting the Monitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...10 D. Calibrating and Servicing the Monitors. . . . . . . . . . . . . . . . . . . . . . . . . 10 E. Testing the Monitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...10 F. An Example ofan SNMMonitor Application. . . . . . . . . . . . . . . . . . . . . . 11 COSTS OF GAMMA-RAY SNMMONITORS . . . . . . . . . . . . . . . . . . . . . . 11 WHAT ABOUT NEUTRON MONITORS? . . . . . . . . . . . . . . . . . . . . . . ..12 Part 2. THE TECHNICAL BASIS OF RADIATION MONITORING . . . . . . . . . . . . . 13 I. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..13 IL A BRIEF HISTORY OF RADIATION MONITORING . . . . . . . . . . . . . . . . . 13 111. GAMMA RADIATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 A. Radioactive Decay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...14 B. Gamma-Ray Energy Spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...15 C. Gamma-Ray Interactions with Materials . . . . . . . . . . . . . . . . . . . . . . . . 15 D. The Inverse Square Law of Radiation Intensity. . . . . . . . . . . . . . . . . . . . . 17 Iv. GAMMA-RAY SOURCE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . 18 A. Background Radiation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...18 B. Gamma-RadiationT estSources. . . . . . . . . . . . . . . . . . . . . . . . . . ...20 C. Characteristics of Transient Diversion Signals . . . . . . . . . . . . . . . . . . . . . 21 l. SNMSelf-Absorption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...21 2. SNMDiversion Signal Profiles . . . . . . . . . . . . . . . . . . . . . . . . . . ..22 v. SNMGAMMA-RAY SOURCE DETECTION. . . . . . . . . . . . . . . . . . . . . . . 24