SIST EN 60405:2008
Nuclear instrumentation - Constructional requirements and classification of radiometric gauges
Nuclear instrumentation - Constructional requirements and classification of radiometric gauges
Specifies constructional requirements for the design of instruments and the radiation protection to be provided in the case of radiometric gauges. Special attention is drawn to the stability of the source housing in the event of fire.
Strahlungsmessgeräte - Konstruktionsanforderungen und Klassifikation radiometrischer Einrichtungen
Instrumentation nucléaire - Prescriptions de construction et classification pour les jauges de mesure des rayonnements ionisants
Spécifie les prescriptions de construction concernant la conception de l'instrument et la radioprotection à mettre en oeuvre dans le cas de jauges radiométriques. Une attention spéciale est portée à la stabilité du boîtier de la source en cas d'incendie.
Jedrska merilna oprema - Konstrukcijske zahteve in razvrstitev radiometričnih merilnikov
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 60405:2008
01-februar-2008
-HGUVNDPHULOQDRSUHPD.RQVWUXNFLMVNH]DKWHYHLQUD]YUVWLWHYUDGLRPHWULþQLK
PHULOQLNRY
Nuclear instrumentation - Constructional requirements and classification of radiometric
gauges
Strahlungsmessgeräte - Konstruktionsanforderungen und Klassifikation radiometrischer
Einrichtungen
Instrumentation nucléaire - Prescriptions de construction et classification pour les jauges
de mesure des rayonnements ionisants
Ta slovenski standard je istoveten z: EN 60405:2007
ICS:
27.120.01 Jedrska energija na splošno Nuclear energy in general
SIST EN 60405:2008 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
EUROPEAN STANDARD
EN 60405
NORME EUROPÉENNE
July 2007
EUROPÄISCHE NORM
ICS 27.120
English version
Nuclear instrumentation -
Constructional requirements and classification of radiometric gauges
(IEC 60405:2003, modified)
Instrumentation nucléaire - Strahlungsmessgeräte -
Prescriptions de construction Konstruktionsanforderungen
et classification pour les jauges und Klassifikation radiometrischer
de mesure des rayonnements ionisants Einrichtungen
(IEC 60405:2003, modifiziert)
(CEI 60405:2003, modifiée)
This European Standard was approved by CENELEC on 2007-07-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60405:2007 E
---------------------- Page: 2 ----------------------
EN 60405:2007 – 2 –
Foreword
The text of the International Standard IEC 60405:2003, prepared by IEC TC 45, Nuclear
instrumentation, together with common modifications prepared by CENELEC BTTF 111-3, Nuclear
instrumentation and radiation protection instrumentation, was submitted to the formal vote and was
approved by CENELEC as EN 60405 on 2007-07-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2008-07-01
– latest date by which the national standards conflicting
(dow) 2010-07-01
with the EN have to be withdrawn
Clauses, subclauses, notes, tables and figures which are additional to those in IEC 60405:2003
are prefixed “Z”.
Annexes ZA and ZB have been added by CENELEC.
__________
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– 3 – EN 60405:2007
Endorsement notice
The text of the International Standard IEC 60405:2003 was approved by CENELEC as a European
Standard with agreed common modifications as given below.
COMMON MODIFICATIONS
Delete the clause INTRODUCTION in total.
Replace “radiation protection class” with “shielding class” all over the document.
1 Scope and object
In the last sentence of the last paragraph, replace “special attention is attached” with
“special attention may be attached”.
2 Normative references
Add:
EN 60846:2004, Radiation protection instrumentation – Ambient and/or directional dose
equivalent (rate) meters and/or monitors for beta, X and gamma radiation
(IEC 60846:2002, modified)
EN 61005:2004, Radiation protection instrumentation – Neutron ambient dose equivalent
(rate) meters (IEC 61005:2003, modified)
Delete the indications of IEC 61326:2002 and ISO 7205:1986.
3 Definitions
3.4 source holder
Replace “support and contain” with “support and fix”.
Add a note below the definition, reading:
NOTE Z1 In the context of this standard the term source holder means the part of the device which fixes or
holds the source. This can be e.g. the shutter or a part of the housing.
3.6 source housing
Add a note below the definition, reading:
NOTE Z1 If the source housing is not part of a measuring head the term source container shall be used (see
definition 3.Z1).
3.9 collimation device
Delete “useful”.
Add a note below the definition, reading:
NOTE Z1 This term is usually applied to collimators used in combination with detectors.
Add an additional definition 3.Z1, reading:
3.Z1
source container
device which includes the radioactive source, its holder and primary shielding measure and
shutter mechanism, if any
NOTE Z1 The term usually means stand alone source container.
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EN 60405:2007 – 4 –
4 Classification of radiometric gauge types
Add an additional Subclause 4.Z1 below 4.2, reading:
4.Z1 Category C: Source containers for fixed radiometric gauges
Category C comprises stand alone source containers for radiometric gauges equipped with
a shielding and properties for collimation of the useful beam.
The source container shall be designed in such a way that the radiation, except for the
useful beam, is attenuated in conformity with the requirements of this standard.
NOTE Z1 Such source containers are used in fixed level or density gauging systems in which the source holder
and the detector are independent units and the useful beam is not restricted by the detector but by additional
radiation protection measures.
S
Figure Z1 – Category C stand alone source container for fixed level or density gauges
4.3 Radiation protection classes
In Table 1, replace all entries for shielding classes 1 and 7 with “Not to be applied”.
In Table 1, add for shielding class 6 in the first line of 5 cm distance “> 3,0 µSv/h” and in the
first line of 100 cm distance “> 1,0 µSv/h”.
In Table 1, add a new column for class “E” with “≤ 3,0 µSv/h” in the line of 5 cm distance
and “≤ 1,0 µSv/h” in the line of 100 cm distance.
Add the following notes below Table 1:
NOTE Z1 The values given in Table 1 are NOT related to limits required in European or national regulations for
radiation protection. Those limits may require additional measures on site and have to be verified in the specific
application.
NOTE Z2 Referring to 10.1 to each gauge four shielding classes are assigned. Two for "shutter closed" at 5 cm
and 100 cm respectively, and two for "shutter open" at 5 cm and 100 cm respectively.
& &
NOTE Z3 The dose equivalent rate can be measured in terms of H (10) and/or H '(0,07) , see 8.4.
4.4 Temperature class
Replace “Temperature class” with ”Temperature classes” in the headline of 4.4.
In Table 2, replace all entries for temperature class 1 with “Not to be applied”.
In Table 2, replace all entries for temperature class 7 with “Other values”.
Add the following paragraph below Table 2:
If the temperature class corresponding to the testing range of an incorporated source (e.g.
according to ISO 2919) is lower than that of the source housing the temperature class of the
source only shall be used.
5 General requirements
5.2 Source holder
In a), replace “installation” with “installation and de-installation”.
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– 5 – EN 60405:2007
5.4 Alignment of the useful beam
In the first paragraph, replace “collimation device” with “collimating properties” and
“restricts” with “restrict”.
In the second paragraph, replace “Category B” with “Category B and C” and “source
holder” with “source container or the source housing”.
5.5 Other requirements
Delete the preultimate sentence of the last paragraph.
6 Protection against ionizing radiation
6.1 General requirements
Add the following paragraphs below the current text:
Following the ALARA principle in position "shutter closed" of the gauge the shielding class
should be E or 6.
Radiation profiles of gauges may be influenced by the individual application on site and may
require additional measurement after installation (see Annex ZA).
6.2 Requirements for Category A gauges
Begin the last paragraph with “If the shutter of the device is remote-controlled or servo-
controlled, any failure of the control circuits …”
6.3 Requirements for Category B gauges
Replace the second paragraph with:
The shielding housing shall ensure that the dose equivalent rate for the respective shielding
class is adhered to in accordance with 4.3 and this class shall be used for "shutter closed"
indication in the classification according to 10.1.
Add an additional Subclause 6.Z1 below 6.3, reading:
6.Z1 Requirements for Category C source containers
The source container shall ensure that the dose equivalent rate for the respective shielding
class is adhered to in accordance with 4.3.
The source container shall be equipped with shutters for interrupting the useful beam.
If the shutter of the device is remote-controlled or servo-controlled any failure of the control
circuits (e.g. failure of power supply) shall automatically close the shutter. After elimination
of the fault, the shutter shall not automatically open until the system is intentionally returned
to its normal operating mode.
The shielding housing shall include a safety lock in order to prevent unauthorized access to
the source.
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EN 60405:2007 – 6 –
6.4 Resistance of the source housing in case of fire
Replace the whole text of 6.4 with:
A source housing and its shielding device, if any, intended to withstand a case of fire shall
be constructed in such a way that the dose equivalent rate does not exceed the values of
national regulatory limits for a fire reaching an ambient temperature of 800 °C for 30 min.
The radioactive source shall remain shielded.
If the requirements of 9.3 are met, "F" shall be indicated for the fire test condition within the
classification code of 10.1.
If the conditions above are not met or no test is performed, "N" shall be stated for the fire
test condition.
7 Other safety devices
7.2 Protection against non-authorized use
Replace “prevent being used” with “prevent use”.
7.3 Indication of the shutter position
In the last sentence, replace “upon a failure” with “upon a technical failure”.
7.4 Additional warning devices
Delete “the user or” in the last sentence of the first paragraph.
8 Determination of the dose equivalent rate
8.1 General
In the first paragraph, delete “or can be calculated”.
In the second paragraph, add at the end of the first sentence “or of the stand alone source
container (see Figure Z2)” and replace the last sentence with “For non-uniform fields, the
2
dose rate should be averaged over an area of 10 cm .”
Add a note to Figure 4, reading:
NOTE Z1 The container depicted in Figure 4 a) may also be an other appliance for storing or carrying medium,
for example a conveyor belt in case of a bulk flow measurement.
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– 7 – EN 60405:2007
Add an additional Figure Z2 below Figure 4, reading:
Dimensions in centimetres
100
100
S S
5 5
a) - Shutter in closed position b) - Shutter in open position
Key
S source container
NOTE Z2 No measurements are made within the shaded area.
Figure Z2 – Schematic representation of isodistance gauging faces
in the case of stand alone source containers
8.2 Dose equivalent rate measurements in the case of closed shutters
Add the following paragraph below the current text:
In this case the values in the center between source housing and detector housing shall be
taken as practicable and documented for information.
8.4 Procedure for dose equivalent rate measurements
Replace the whole text of 8.4 with:
Appropriate measuring instruments according to EN 60846 (photon and beta radiation) or
EN 61005 (neutron radiation) shall be used for measuring the dose equivalent rate:
&
a) in every case the measuring quantity shall be the ambient dose equivalent rate H (10) ;
b) in the case of low energy (gamma sources) and beta sources an additional
measurement with the measuring quantity directional dose equivalent rate
&
H ' (0,07) shall be undertaken.
For neutron radiation for the distance of 5 cm calculation back from the measurement at
1 m is permitted.
8.5 Determining the relevant values of the dose equivalent rate
Replace the whole text of 8.5 with:
For calculation of the relevant values of the dose equivalent rates for shielding classification
&
according to Table 1, values in terms of H (10) for penetrating radiation are to be used.
&
Values in terms of H ' (0,07) shall be divided by ten before applying Table 1 for
classification.
& &
Where both H (10) and H ' (0,07) are relevant the lowest class of the different measuring
quantities shall be used for classification of the entire gauge.
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EN 60405:2007 – 8 –
9 Test methods
9.1 General
Replace the first paragraph with:
Where proof of the properties required cannot be verified by the prototype tests specified in
9.2 through 9.4 this proof shall be determined by other means (e.g. calculations and
evaluation of the material characteristics).
9.2 Temperature cycle test on the shutters and the source holder
9.2.2 Procedure
In the first paragraph, replace “can be determined” with “shall be determined”.
In the last paragraph, replace the last sentence with “The values shall not be different from
the original values by more than that which could be expected from statistical variation.”
9.3 Test for checking the resistance of the shutter and the source holder in case of fire
Replace the headline of 9.3 with “Test for checking the resistance of the shutter, the
source holder and the source container in case of fire”.
9.3.2 Procedure
Replace the second paragraph with:
The source housing is introduced into a furnace preheated to at least 800 °C and heated
until equilibrium is achieved and then maintained at at least 800 °C for at least 30 min.
Replace the last paragraph with:
If the source has moved (e.g. due to the melting of the shielding material) the dose
equivalent rates that would occur in the case of a real source shall be determined. The dose
equivalent rates derived shall not exceed the limit values in accordance with 6.4 where that
source would be in the most critical place for maximum dose rate.
10 System classification coding and labelling
10.1 Classification code
In the first paragraph, replace “radiometric gauge” with “radiometric gauge or source
container” and “international standard designator IEC 60405” with “standard designator
EN 60405”.
Add a note below the first paragraph, reading:
NOTE Z1 The classification code may depend on the source characteristics (e.g. activity, temperature range,
radionuclide, encapsulation, accident conditions).
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– 9 – EN 60405:2007
Replace the shown example for the classification code with:
Gauge category
Suitability under normal
operating conditions
EN 60405 – A E E 3 3 2 1 F
Fire test condition
Temperature class: minimum operating temperature for which the gauge is
designed
Temperature class: maximum operating temperature for which the gauge is
designed
Shielding class: dose equivalent rate at 100 cm distance – shutter open
Shielding class: dose equivalent rate at 5 cm distance – shutter open
Shielding class: dose equivalent rate at 100 cm distance – shutter closed
Shielding class: dose equivalent rate at 5 cm distance – shutter closed
11 Accompanying documents
Replace item b) with
b) the information on labelling given in Clause 10 and an application that the
classification is in accordance with the provisions given EN 60405;
Add a note below item c), reading:
NOTE Z1 In some cases it may be necessary to describe the basis of the dose rate calculation.
Replace item g) with
g) certificate related to the leakage of radioactive material from the source;
In item h), replace “is to be performed” with “are to be performed”.
Add the following new items k), l), m) and n):
k) in case of shielding class 2 (see Table 1) indication of the respective dose rate
value(s);
l) in case of temperature class 7 (see Table 2) indication of the respective
temperature(s);
m) instructions for appropriate radiation protection measures;
n) value according to 8.2 if the measuring gap is below 10 cm for information.
---------------------- Page: 10 ----------------------
EN 60405:2007 – 10 –
Additional Annex ZA
Add additional Annex ZA, reading:
Annex ZA
(informative)
Guideline for installation of radiometric gauges
This guideline is intended to give examples of aspects which may be required to be
considered in design, operation or servicing of gauging systems.
It is recommended to undertake a radiation protection risk analysis before installation and to
verify the protective measures by measurements before operational use.
1) Due to the purpose of shielding penetrating radiation (e.g. gamma radiation) the source
container or auxiliary screening measures may have a considerable weight that can
easily exceed several 100 kg. This shall be taken into consideration when planning
– mounting brackets or consoles;
– installation, e.g. with cranes;
– access to the source container for service purposes.
2) For reduction of the possible dose exposure, the useful beam shall not be directed
towards places of high foot traffic. Besides that, the dose equivalent rate at the detector
side has to be considered as well as the dose equivalent rate at the source container.
While reduction of the dose equivalent rate at the source container is simply possible by
slightly increasing the distance (inverse square law), this is unlikely to apply to the
detector side because the distance to the source is already considerable. Also the dose
equivalent rate at the detector has to be considered under worst conditions (e.g. empty
vessel).
3) Access to the useful beam between source container and e.g. vessel at least in case of
Category A or C gauges shall be restricted.
4) Figure ZA.1 gives examples of protection principles which may be required to be
considered in design or operation of gauging systems.
---------------------- Page: 11 ----------------------
– 11 – EN 60405:2007
In direction of the useful beam
Shielding
Shielding
increased dose rates are to be
expected and may require
additional shielding or area with
restricted access.
The dose rate values at a certain
point may differ significantly
depending on the kind and
condition of medium or whether
medium is present or not.
Wall
Walls, floors and ceilings do not
provide sufficient shielding in
ceiling,
every case.
floor
SD
Additional shielding or restricted
areas may be required.
Backscattering
effects
Backscattering effects shall be
taken into consideration.
Such effects may depend on the
Shielding
properties of the medium to be
measured or on geometrical
circumstances of the application.
Subsequent fittings may change
Shielding
the backscattering conditions.
Backscattering
effects
Access
Sufficient access protection shall Access
Access
Protection Protection
be provided.
Protection
Protective measures shall be
SD
taken for maintenance / servicing
activities where additional
shieldings have to be removed or
the restricted area has to be
accessed.
protective
Appropriate protection against measure
chemical and mechanical
influences shall be provided to
keep the source under control in
any event.
intentionally left blank
Locally increased dose rates due
intentionally left blank intentionally left blank
to adjacent gauges shall be
considered.
Figure ZA.1 – Examples of protection methods and principles
---------------------- Page: 12 ----------------------
EN 60405:2007 – 12 –
Annex ZB
(normative)
Normative references to international publications
with their corresponding European publications
The following referenced documents are indispensable for the application of this document. For
dated references, only the edition cited applies. For undated references, the latest edition of the
referenced document (including any amendments) applies.
NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
IEC 60476 1993 Nuclear instrumentation - Electrical measuring - -
systems and instruments utilizing ionizing
radiation sources - General aspects
IEC 60692 1999 Nuclear instrumentation - Density gauges - -
utilizing ionizing radiation - Definitions and test
methods
IEC 60846 2002 Radiation protection instrumentation - Ambient EN 60846 2004
(mod) and/or directional dose equivalent (rate) meters
and/or monitors for beta, X and gamma radiation
IEC 60982 1989 Level measuring systems utilizing ionizing - -
radiation with continuous or switching output
IEC 61005 2003 Radiation protection instrumentation - Neutron EN 61005 2004
(mod) ambient dose equivalent (rate) meters
IEC 61010-1 2001 Safety requirements for electrical equipment for EN 61010-1 2001
measurement, control, and laboratory use - + corr. June 2002
Part 1: General requirements
IEC 61336 1996 Nuclear instrumentation - Thickness - -
measurement systems utilizung ionizing
radiation - Definitions and tests methods
ISO 361 1975 Basic ionizing radiation symbol - -
ISO 921 1997 Nuclear energy - Vocabulary - -
ISO 2919 1999 Radiation protection - Sealed radioactive - -
sources - General requirements and
classification
---------------------- Page: 13 ----------------------
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---------------------- Page: 14 ----------------------
60405 IEC:2003 – 3 –
CONTENTS
FOREWORD . 7
INTRODUCTION .11
1 Scope and object .13
2 Normative references.13
3 Definitions.15
4 Classification of radiometric gauge types.17
4.1 Category A: Radiometric gauges with restricted beam .17
4.2 Category B: radiometric gauges with omnidirectional beam.19
4.3 Radiation protection classes.19
4.4 Temperature class .19
5 General requirements.21
5.1 Measuring gap .21
5.2 Source holder .21
5.3 Source housing.21
5.4 Alignment of the useful beam .21
5.5 Other requirements .23
6 Protection against ionizing radiation .23
6.1 General requirements .23
6.2 Requirements for Category A gauges .23
6.3 Requirements for Category B gauges .23
6.4 Resistance of the source housing in case of fire .25
6.5 Detector housing.25
6.6 Measuring head .25
7 Other safety devices .25
7.1 General .25
7.2 Protection against non-authorized use.25
7.3 Indication of the shutter position.25
7.4 Additional warning device.25
8 Determination of the dose equivalent rate.27
8.1 General .27
8.2 Dose equivalent rate measurements in the case of closed shutters.29
8.3 Dose equivalent rate measurements in the case of open shutters .29
8.4 Procedure for dose equivalent rate measurements .29
8.5 Determining the relevant values of the dose equivalent rate.31
9 Test methods .31
9.1 General .31
9.2 Temperature cycle test on the shutters and the source holder .31
9.3 Test for checking the resistance of the shutter and the source holder
in case of fire.33
9.4 Test for checking the mechanical resistance of the shutter and
the source holder .35
10 System classification coding and labelling .35
10.1 Classification code.35
10.2 Labelling.37
11 Accompanying documents.37
---------------------- Page: 15 ----------------------
60405 IEC:2003 – 5 –
Figure 1 – Schematic arrangement of Category A gauges .17
Figure 2 – Schematic arrangement of Category B gauges .19
Figure 3 – Schematic representation of isodistance gauging faces in the case of
thickness gauges.
...
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