IEC 60761-5 pdf download – Equipment for continuous monitoring of radioactivity in gaseous effluents – Part 5: Specific requirements for tritium monitors

IEC 60761-5 pdf download – Equipment for continuous monitoring of radioactivity in gaseous effluents – Part 5: Specific requirements for tritium monitors
1scope and object
This part of lEC 60761 is applicable to equipment intended for the simultaneous, delayed ordiscrete sequential measurement of tritium in any gaseous form in gaseous effluents dis-charged into the environment.
lt is applicable to equipment designed to fulfill the following functions:
the measurement of the concentration of tritium in the gaseous effluents at the dischargepoint and its variation with time;
the actuation of an alarm when a predetermined volumic activity or a predetermined totalreleased radioactivity is exceeded.
The equipment may also be used for the determination of the tritium activity discharge over agiven period.
The object of this standard is to establish specific standard requirements，including technicalcharacteristics and general test conditions and to give examples of acceptable methods for thetritium effluent monitors defined in clause 4.
The general requirements, technical characteristics, test procedures, radiation characteristics,electrical,mechanical，safety and environmental characteristics are given in lEC 60761-1.Unless otherwise stated, these requirements apply in this standard.
2 Normative references
The following normative documents contain provisions which，through reference in this text,constitute provisions of this part of lEC 60761.For dated references,subsequent amendmentsto，or revisions of，any of these publications do not apply. However，parties to agreementsbased on this part of iEc 60761 are encouraged to investigate the possibility of applying themost recent editions of the normative documents indicated below. For undated references,thelatest edition of the normative document referred to applies. Members of lEC and lS0 maintainregisters of currently valid lnternational Standards.
IEC 60068-2-27:1987,Environmental testing – Part 2:Tests. Test Ea and guidance:Shock
IEC 60761-1:2002,Equipment for continuous monitoring of radioactivity in gaseous effluents -Part 1: General requirements
IEC 61000 (all parts), Electromagnetic compatibility (EMC)
EN 55022:1994,Limits and Methods of Measurement of Radio Disturbance Characteristics ofInformation Technology Equipment
3Terms and definitions
For the purpose of this part of lEC 60761, the following definitions apply:
3.1
tritium effluent monitor
equipment designed for the continuous monitoring of tritium in gaseous effluents discharged tothe environment
3.2
tritium
unless otherwise stated,”tritium”, in this standard,covers tritium in gaseous or vapour forms,whether chemically combined or not
4Classification of tritium effluent monitors
The equipment may be classified according to the type of measurement as:
selective monitors,for the selective measurement of one particular form of tritium (gas,tritium oxide or any tritiated compoundy;
non-selective monitors, for the overall measurement of tritium in all its forms.
5 Sampling and detection assembly
5.1Sampling and exhaust pipes
ln addition to the general requirements of lEC 60761-1, the following characteristics shall beconsidered and shall be agreed between manufacturer and purchaser:
– the nature of the materials used,paying particular attention to chemical corrosion,
electrostatic effects, memory effects,etc.;
the minimum distance between inlet and outlet to avoid recirculation;
– the prevention of condensation in the pipe by variation of temperature or pressure;- the ease of decontamination.
5.2 lnlet filter
A filter shall be placed in a filter-holder at the sampling circuit inlet to remove any dust andaerosols from the air. In order to maintain the specified performance of the equipment, such afilter shall not trap, or even temporarily,retain tritium.
All necessary arrangements shall be made to control the pressure drop in the filter.The systemshould be designed to allow filter change at a given pressure drop to ensure that an intact filteris in place.
5.3Ease of decontamination
ln order to avoid interference with measurements，it is recommended that all necessaryarrangements be made to limit the contamination of the detector. In all cases, the detectionassembly shall be easy to dismantle, decontaminate and reassemble.
5.4 Collection medium
If the detection assembly includes an absorbent medium, intended to collect a specific chemical form of tritium, its characteristics, efficiency, retention capacity and delay time constant shall be known for the various radioactive gases of significance in the effluent.