IEC 60761-1:2002 pdf download

IEC 60761-1:2002 pdf download.Equipment for continuous monitoringof radioactivity in gaseous effluents -Part 1: General requirements.
3.21
sensitivity
for a given value of the measured quantity, ratio of the variation of the observed variable to the corresponding variation of the measured quantity
3.22
volumic activity
activity per unit vo’ume of air or gas
3.23
surfac. emission rate of solid sources
number of particles of a given type above a given energy emerging from the front face of the source per unit time
3.24
test nomenclature
3.24.1
type test
a test of one or more devices made to a certain design to show that the design meets certain specifications
[1EV 151-04-15J
3.24.2
routine test
a test to wtiich each Individual device Is subject during or after manufacture to ascertain whether It complies with certain criteria
[1EV 151-04-16]
3.24.3
acceptance test
a contractual test to prove to the customer that the device meets certain conditions of its specification
[1EV 151-04-201
3.24.4
maintenance test
a test carried out periodically on a device o equipment to ascertain and, If necessary, make certain adjustments to ensure that Its performance remains within specified limits
[1EV 151-04-22]
3.25
manufacturer and purchaser
the term manufacturer includes the designer and the seller of the equipment.
The term purchaser includes the user of the equipment.
3.26 Units
This standard uses the SI system of units. The following units of practical importance are also
used where appropriate:
— for time: year (y), day (d), hour (h), minute (mm);
— for energy: electron-volt (eV);
— for volumic activity: Becquerel per cubic metre (BqIm3).
4 Symbols and abbreviations
MTBF Mean Time Between Failures.
5 General requirements
The primary purpose of radioactive effluent monitoring equipment is, generally, to provide assurance that the effluent discharged from each establishment conforms to the authorized discharge limits.
It may also provide the purchaser with data relevant to the control of any process carried out. While this is usually a secondary purpose, in certain circumstances, situations may be envisaged where the detection of activities significantly below the allowed discharge limits may give early warning of plant malfunction.
Irrespective of whether the proposed effluent monitoring is intended to meet the requirements of the responsible authority or is mainly intended to provide control information to the purchaser, the most likely requirement is the capability to measure a defined level of discharge, characterized by its volumic activity and the total effluent flow-rate.
This capability is affected by a number of factors including detector type and performance, mode of operation of the monitor, dilution of activity in the overall effluent stream, and effectiveness of the sampling system (where part, not all, of the effluent stream is actually measured).
Of the various factors involved, it is obviously possible to optimize, at a very late stage, the detailed monitor design, but often not enough thought is given, early in plant design, to the possible monitoring requirements and how the overall effluent system should be arranged so as to allow effective monitoring at the sensitivity level required. Thus, for maximum performance capability, it is recommended that the need for and the necessary performance of monitoring equipment be identified early In the design of any plant and the plant design influenced as necessary to achieve the requirements.
6 Types of monitors
6.1 General
The types of gaseous effluent monitoring envisaged are radioactive aerosol monitors, radioactive noble gas monitors and specific radionuclide monitors. They are dealt with in detail in the other parts of this standard. However, the following summary highlights some significant features.
6.2
Aerosol monitors
Such equipment generally includes some means of collection on a sampling medium such as a fixed filter or a moving filter which is monitored by a suitable detection assembly. The detector chosen shall be appropriate to the particular radioactivity of interest and be consistent with the performance requirements of IEC 60761-2.