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EMDC 6(6618 )  
 
 
 
DRAFT TANZANIA STANDARD  
 
 
Protection against i onizing r adiation : Specification  for industrial 
radiogra phic installations  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1 
 0. Foreword  
The problem of ionizing radiation pollution is exacerbated by improper land use planning, failure to follow 
building permits in most of our cities, municipalities and towns. This Tanzania Standard is developed partly 
due to the requirements of the law (EMA, 2004) and partly becau se of the public outcry on randomly 
construction of ionizing radiation facilities without using standards. Therefore, the requirements  values 
provided by this Tanzania Standard will provide the basis for authorities to assess and manage building 
enclosing ionizing radiation facilities.   
In preparation of this Tanzania Standard, considerable assistance was derived from  
Management of Radiation Protection in Defense Part 2: Leaflet 28 - Industrial radiography 
including enclosures, site and underwater radiograp hy. September 2013.  
IAEA Safety Standard for protecting people and the environment; Radiation Safety in  
Industrial Radiography  Specific Safety Guide  No. SSG -11 International Atomic Energy 
Agency Vienna, 2011  
Safety Report Series Radiation Protection and Sa fety in Industrial Radiography International 
Atomic Energy Agency Vienna, 1999  
In reporting the result of a test or analysis made in accordance to this Tanzania Standard, if the final 
value, observed or calculated is to be rounded off, it shall be done in accordance with TZS 4 (see 
clause 2).  
 
 
 
 
 
 
 
 
  
2 
 Introduction  
The applications of ionizing radiation bring many benefits to humankind, ranging from power generation to uses 
in medical institutions, agriculture and industry.  One of the lengthiest established industrial applications of 
radiation is the use of radiogra phy for the non -destructive testing where by many types of manufactured 
components can be inspected to validate the internal structure and integrity of the sample. Industrial radiography 
provides a means of verifying the physical integrity of equipment and  structures such as vessels, pipes, welded 
joints, castings and other devices. The integrity of this equipment affects not only the safety and quality of the 
products used by workers, but also the safety and quality of the environment for workers and the p ublic at large.  
In particular, radiography can be performed so as to pose a negligible risk on the public and with sufficiently low 
occupational radiation exposure so as to pose no unnecessary radiological risk on the workers. However, 
experience has also  shown that bad practice in industrial radiography resulted in high doses to a person 
accidentally exposed to the primary beam or in close contact with an unshielded source. The consequences of 
such practice might also results in injury to workers, causing  severe health problems such as radiation burns and 
in other situation death might occurred.  
 
Members of the public can also suffered radiation over exposures when radioactive sources used for industrial 
radiography were not properly controlled or regulat ed. Industrial radiographic  work by its nature is often carried 
out under difficult working conditions in a variety of locations and under different environmental situations, such 
as in narrowed or restricted areas or in a place whereby extreme cold or hea t exists. Working under such adverse 
conditions might result in operational situations in which the principle of keeping doses as low as reasonably 
achievable (ALARA) is challenged. All of these features demonstrated the necessity for governmental 
organiza tions to set the required standards and regulation in an environment that promotes a safety within the 
organizations, environment and general public at large. It is assumed that, this Safety standard will facilitate in 
the laying down of effective legal an d regulatory steps that ensure effective measures are in place to limit the 
radiation exposure to any p erson as a result of radiographic  operations wherever they are conducted.  
 
 
 
 
 
 
 
 
 
 
 
  
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 1. Scope  
This Tanzania  standard provides requirement for design of industrial radiograph ic installations for the use 
of sealed nuclear substances, including fixed (perm anent) and temporary structures .  It is only concern 
with radiation protection and safety for occupational, general public and environment and does not deal 
with radiographic techniques for non -destructive testing.  
2. Normative References  
TZS942:2017/ ISO 7212:1986  Enclosures for protection against ionizing radiation -- Lead shielding units 
for 50 mm and 100 mm thick walls  
ISO 14152:2001 Neutron radiation protection shielding -Design parameters and considerations for the 
choice of appropriate materials  
ISO 2919:20113   Sealed radioactive sources –General requirements and classification  
ISO 12749 -4:2015  Nuclear energy, nuclear technologies, and radiological protection -- Vocabulary -- 
Part 4: Dosimetry for radiation processing  
ISO 3999:2004  Radiation pro tection -Apparatus for industrial radiography –Specifications for 
performance, design and tests  
ISO 361:1975  Basic  Ionizing Radiation Symbol.  
3. Terms and definitions  
For the purpose of this Tanzania standard, the following definition shall apply:  
3.1 barrier  
a physical obstruction that prevents or inhibits the movement of people, radionuclides or some other 
phenomenon (e.g. fire), or provides shielding against radiation.  
3.2 controlled area  
area set up before any radiographic exposure is undertaken outside an enclosure within an establishment 
where all areas outside it are to be at dose rates (over 1 minute) of less than 7.5 µSv/hr.  
3.3 industrial radiography  
Method of non -destructive testing whe re many types of manufacturing components can be explained to 
verify the internal structure and integrity of the specimen using ionizing radiations.   
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 3.4 ionizing radiation  
electromagnetic radiation and subatomic particles with sufficient energy to overcome  the binding energy of 
electron(s) in atom(s) or molecule(s) thus creating ion(s)  
3.5 occupational exposure  
contact with a potentially harmful physical, chemical, or biological agent as a result of one's work  
 
3.6 permanent radiographic  installations   
an enclosed  shielded room, cell, or vault, not lo cated at a temporary radiographic  installation, in which 
radiography is performed . 
3.7 radiation source  
material or apparatus emitting or capable of emitting ionizing radiation  
3.8  radiograph ic installations  
are an enclosed shielded rooms, cells, or vaults, located within establishment, in which radiography is 
performed.  
3.9 sealed radioactive source  
radioactive source sealed in a capsule or having a bonded cover, the capsule or cover being strong enough 
to prevent contact with and dispersion of the radioactive material under the conditions of use and wear for 
which it was designed  
 3.10 site radiography  
method of non -destructive testing (NDT)  where many types of the manufactured components can be 
examined to verify the internal structure and integrity of the specimen on site outside using either x -rays or 
gamma rays.  
3.11 supervised area  
area set up before any radiographic exposure is undertaken outside an enclosure within an establishment 
where all areas outside it to be set such that the expected annual biological full body dose to a person from 
normal operation and likely accident, duri ng the time the area or room is accessible is between 1 mSv to 6 
mSv.  
  
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 3.12 survey meter  
A portable instrument that measures radiation dose rate.  
3.13 shielded enclosure:  
an enclosed space engineered to provide adequate shielding from ionizing radiation for persons in the 
vicinity.  
 
3.14 temporary  radiograph ic installations   
any location where industrial radiography  is performed and where licensed material may be stored other 
than those locations of use authorized on the license  or registration . 
3.15 Warning sign  
sign used as a warning to protect people from being exposed to radiation. The sign must be posted where 
radioactive materials are handled or radiation -producing equipment is used.  
4. Requirements for design of industrial radiograph ic installations . 
Design principles for industrial radiograph ic installations are based on the requirement that all operating 
organizations shall ensure that any radiation exposures as a result of radiograph ic operations remain within 
the national and international best practice requirements.  
4.1 Requirements for shielded enclosure  
 
i. A shielded enclosure shall  be designed to take account of the radiation sources that are to be 
used and the specific work that is to be carried out.  
ii. The enclosure s hall be designed so that the exposure controls for the gamma source or radiation 
generator are located outside the shielded enclosure.  
iii. The design shall  be planned for immediate and foreseeable future needs before the 
commencement of construction.  
iv. The design o f the shield ed enclosure shall  include a drawing of the installation and its 
surroundings, including any adjacent offices or buildings.  
v. The drawing shall  include dimensions, as well as the thicknesses, densities and types of shielding 
materials on all sid es of, above and below the exposure area.  
 
vi. Entrances shall  be marked and distances to potentially occupied areas adjacent to, above an d 
below the exposure area shall  be indicated, including information on the occupancy factor (i.e. the 
frequency of occupation and the average   
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 4.1.1  Designation of shielded enclosures  
i.  The designation of radiographic enclosures as controlled areas during the exposure of 
radiographic sources or  the operation of an industrial X -ray set is to be undertaken in consultation 
with the R adiation Protection Authority (RPA) . 
ii. Suitable controlled radiation areas signs detailing the nature of the radioactive source and the risks 
arising from the source, shall be displayed around the perimeter of the controlled area and at each 
entrance to the enclosure.  
iii. Suitably worded signs shall be posted on each outside wall of the radiation enclosure to warn, 
where appropriate, against access to the roof without the per mission of the Radiation Protection 
Supervisor ( RPS). 
iv. Where radiographic sources are used, the radioactive source store shall be a controlled radiation 
area. The store is to be appropriately marked and display a sign on the door listing the radioactive 
contents within the store and the risks arising from the sources held.  
v. All controlled and supervised areas are to be suitably de scribed in local orders.  
 
4.1.2  Access to shielded e nclosures  
Entry to the radiographic  enclosure is prohibited during radiation exposure other than in special 
circumstances under a permit -to-work such as in returning a radiographic source to its container 
when it cannot be returned from outside the enclosure. All such special procedures shall be 
undertaken in consultation with the RPA.  
 
4.1.3  Design of shielded e nclosures  
i. Enclosures for industrial radiography using radioactiv e sealed sources or X -rays shall provide 
sufficient shielding to reduce the radiation dose rate to 7.5 μSv/hr at any point on the  surface of the 
outside wall of the enclosure. Additional shielding shall be provided for facilities  in constant use. 
New facilities shall be designed, where re asonably practicable, to provide  sufficient shielding such 
that the external dose rate will not exceed 1 μSv/hr.  
ii.  Control panels for X -ray machines or radioactive sourc es shall be situated outside the walled 
enclosure.  
iii. Where an X -ray machine is used, inter locks shall be pr ovided and maintained to ensure that should 
any door to the enclosure be opened whil e an X -ray machine within it is energized , the machine 
shall be automatically de -energized  and cannot be operated so long as that door  remains open.  
iv. Where a radioactive sealed source is used, where reasonably practicable, interlocks shall be 
provided and maintained at all entrances to an enclosure, such that while a sealed  source is exposed 
no door to the enclosure can be opened, and that a sealed source can not be exposed while any 
door is open.   
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 v.  Where an interlock has been opened, a radiographic exposure is not to re -start simply by  remaking 
the interlock. It shall be necessary to re -set the interlocks and the operator shall go through the re -
start sequence at the control point before the X -ray machine or sealed source  can be exposed.  
vi. All interlocks shall be designed and positioned so that t hey cannot easily be interfered with, and are 
to be of a fail -safe type.  
vii. Interlocks shall be regularly examined and test ed at a frequency laid down in the local  orders. 
Records of such tests shall be maintained, to identify the tests carried out, any  actions required to 
maintain the interlocks and the date for next examination . 
viii. For the protection of persons accidentally  locked inside an enclosure, an alarm shall to be provided 
to summon help from outside the enclosure. In addition, in all X -ray facilities and, where reasonably 
practicable, sealed source radiography, a means of controlling the radiation source from inside the 
room is to be provided. Such a control  is to prevent exposure from taking place if activated outside 
the exposure phase, and terminate if operated during an exposure.  
ix. A sufficient number of prominently marked controls (stop buttons or pull cords) shall be provided such 
that they can be activa ted promptly and without crossing a main exposure beam. These controls are 
to be of a type that needs to be positively re -set from the location at which they were operated before 
further exposures may be initiated. Such devices are to be regularly tested a nd documented. If it is 
not reasonably practicable to control the sources from inside the room, a shielded refuge is to be 
provided inside the enclosure. The RPA shall be consulted about the design of this refuge.  
x. A prominent notice shall be displayed in t he enclosure explaining the actions to be taken in the event 
of being accidentally locked  inside the enclosure.  
xi.  Where manually operated source wind out systems are used, or where the dose rate exceeds 50 
mSv min-1 at 1 m from the source, a search -and-lockup system shall be provided and operated before 
each exposure, to ensure that no -one may be accidentally locked  inside at the beginning of an 
exposure.  
xii. Where an enclosure has been designed in a way  that limits  positioning of the radiograph ic source or 
the X -ray machine within the enclosure, th e equipment operating area shall  be clearly marked . 
 
4.1.4  Radiation w arning d evices  
 
i. Adequate warning to all persons in the vicinity shall be given by appropriate visual or  audible signals, 
or both:  
a. When a sealed source is about to be exposed, or when an X -ray machine is about to be 
energized (pre -exposure warning alarm ); 
b. While a source is exposed or an X -ray machine is energized  (continuous exposure warning 
alarm).  
ii. The duration of the p re-exposure warning a larm shall be sufficient ly long  for anyone accidentally 
locked inside the enclosure to take appropriate action.   
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 iii. The pre -exposure warning alarm shall be easily distinguishable from the continuous exposure 
warning alarm and both warnings shall be clearly exp lained on well sited signs. To achieve this, a 
warning signal may be combined with a sign in the form of an illuminated sign.  
iv. In the case of X -ray machines, and sealed sources capable of producing >10 mSv min-1 at a distance 
of 1 m, the warning signals and illuminated signs shall be arranged to operate automatically.  
v. Warning signals shall be installed inside the enclosure and outside each entrance to the enclosure.  
vi. A further exposure warning signal (such as a r ed light) shall be activated on the control panel and is 
to remain on long enough for the indication to be seen by the operator irrespective of the exposure 
duration.  
vii. Warning devices for X -ray enclosures shall be fail -safe, i.e. if the warning device fails  the exposure 
will not proceed. If reasonably practicable, warning devices for sealed source  enclosures are to be 
fail-safe.  
viii. All warning signals shall  be regularly examined and tested to ensure their satisfactory operation. 
Records of such checks shall be maintained, to identify the tests carried out, any actions required 
to maintain the interlocks and the date the next examination is due.  
ix. Explanatory notices are to be provided to inform employees and other persons as to the purpose of 
the warning signal. T he notice shall be in both Swahili and English.  
 
4.1.5 Operating Procedures  
 
i. Work involving the exposure of sealed sources or operation of an X -ray set is only to be undertaken 
in accordance with practice  related rules  and written arrangements drawn up by the establishment 
in consultati on with the RPA . Non -classified persons are only to enter a controlled area under writ ten 
arrangements . 
ii. The movement or manipulation of sealed sources shall be undertaken by remote contro l. 
Radiographic sources shall never be handled with bare or gloved hands.   
iii. The radiograph ic set-up is to be completed before the X -ray machine is energized or the sealed 
source is exposed. No material is to be brought into the radiation beam except by the use of 
mechanisms operated from outside the enclosure.  
iv.  Where there are limitations on the location of these equipment’s  inside the enclosure, the 
radiograp hic source or the X -ray machine shall  only be operated in the demarcated area  
v. Before an X -ray machine is operated, or a sealed source is exposed, a search of the enclosure shall 
be made to ensure that no one has been accidentally  locked  inside.  
vi. After each exposure, personnel approaching the source shall do so with a dose rate monito ring 
instrument to verify that the X -ray machine has de -energized or that the source has retracted fully 
home into its container. Where ver possible  practicable, suitable electronic alarming dosimetry 
should also be worn.   
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 vii. The dos e rate outside an enclosure shall be checked regularly and particularly after any change of 
radiation source or methods of work. The results shall be recorded in a survey report which is to be 
retained for a period of at least 2 years from the date of completion.  
viii. All radiation protec tion and monitoring instruments used in radiographic work shall be calibrated and 
tested.  
 4.2 Requirements for site radiography  
When objects to be radiographed cannot be physically moved into a shielded enclosure, the work sh all 
be carried out under ‘site radiography’ conditions. This method of radiography is very common, but it is 
potentially hazardous because of the absence of engineered safety measures.Site radiograph ic work can 
be performed with gamma radiographic  devices, X ray equipment or mobile  accelerators.  
 
4.2.1  Movement and transport of sources  
When gamma exposure devices and sources are to be moved around a work  site, they shall  not to 
be removed from the storage facility until they are ready to be  used. The sources are to be moved 
only in appropria te containers such as transport packages which are locked correctly and the keys 
of which are removed.  The requirements for transportation of radioactive materials shall follow 
International Atomic Energy Agency ( IAEA ) Safety Standards Series No. S T-1. 
4.2.2  Storage of Radiograph ic Sources  
If it is necessary for a radiographic sealed source to be stored on site, it shall be stored in accordance 
with the general requirements. For short term exercises, where sources are used away f rom their 
base locations, it is acceptable for sources to be stored in their source containe r and transport 
packaging, in a locked and placarded vehicle in a secure area. For sources subject to H igher Activity 
Sealed Sources (HASS)  regulatory control , the conditions on the notification certificate shall be 
applied.  
4.2.3 Controlled Areas  
i) A controlled area shall  be set up before any radiographic  exposure is undertaken outside an 
enclosure. The ext ent of the controlled area shall  fulfil the following, unless otherwise advised by the 
RPA:  
a) Within an establishment, all areas outside the controlled area are to be at dose rates  (averaged 
over one minute) of less than 7.5 μSv/hr. Barriers and signs are to be set up  where dose rates 
exceed 2.5 μSv/hr.   
b) The extent of controlled areas is to be determined in consultation with the RPA, initially  by 
calculating the appropriate distance from the source to the 7.5 μSv/hr dose rate  contour within  
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 an establishment. On exposure of the sealed source or the  X-ray machine,  dose rate 
measurements are to be taken and the barrier moved until the dose rates do not  exceed 7.5 
μSv/hr or 2.5 μSv/hr, as appropriate.  
c) It is to be set up so that access control can be effectively achieved. Access to  controlled areas 
is to be restricted by the use of barriers, fixed structures, (such as the  walls of buildings or 
bulkheads of ships).  
d) It is to be minimized  by utilizing  local shielding such as walls, beam collimation etc.  
ii) Except where it is unavoidable for the purposes of  initiating or terminating an exposure,  where dose 
rates up to 2  mSv/hr would be permissible, no one shall work inside the controlled or  supervised areas 
until the exposures are complete.  
iii) Where radiography is undertaken in a multi -storey building or o n board ship, controlled  and 
supervised areas are not only to include areas on the sam e level, but where appropriate, levels above 
and below the source of the radiation shall  be designated.  
iv) Suitable warning signs shall  be displayed a t appropriate points around the perimeter of the controlled 
areas, such that a person approachi ng the controlled area from any direction would be made aware of 
the hazard. The signs shall state that the area is a controlled area and give details of the rad iation 
hazard and the risks arising from the radiation source being used. An appropriate number of guards  
are to patrol the perimeter of th e controlled area to prevent unauthorized  entry.  
v) All controlled areas shall be suitably described in practice rela ted roles . For site radiography, this 
can most easily be achieved by maintaining  distances from the sealed source or X -ray machine.  
 
4.2.4 Equipment Requirements  
4.2.4.1 X-Ray Apparatus  
Where X -ray machines are used, the following requirements are to be fulfilled:  
i. The beam filtration on the X -ray tube shall be equivalent to at least 2 mm of  aluminium;  
ii. The leakage rate from the X -ray tube housing shall not exceed 2.5 mSv/hr  at 1 m from the focal 
spot at the maximum rated voltage and current, and for pulsed  X-ray tubes at the maximum 
pulse rate;  
iii. The lengths of cables from the X -ray machines shall  be long enough to  enable the control 
panel, whenever reasonably practicable, to be outside the controlled  area;  
iv. For X -ray units operating up to 300 kV, cables of not less than 20 m in  length shall be used. 
Longer cables are required for X -ray units operating at greater than  300 kV. Control cables to  
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 warning signal devices shall be equal or greater in length than  the tube head to control panel 
cables;  
v. The X -ray set shall be provided with a means of collimation to restrict the  radiation beam to the 
minimum size necessary for the work;  
vi. The equipment shall be electrically safe;  
vii. The equipment shall be  provided with a means of preventing unauthorized  use (e.g. a key 
opera ted switch).  
4.2.4.2 Sealed Sources  
Sealed sources used in site radiography shall be pr ovided with a suitable means of collimation to restrict 
the extent of the radiation beam to a  minimum necessary to undertake the work and operated via a 
keyed switch to prevent unauthorized  use. 
4.2.5 Warning Signals  
i. Adequate warning of the impending or actual presence of radiation shall be given to all persons within 
or approaching the marked off area during site radiography by appropriate visual or audible signals, or 
both. The two signals are as follows:  
a)  When a source is about to be exposed or when an X -ray machine is about  to be energized 
(pre-exposure warning alarm);  
b) While a source is exposed or an X -ray machine is energized (continuous  exposure warning 
alarm).  
ii. The duration of the pre -exposure warning alarm shall be sufficient ly long  for anyone within the  
controlled area to walk clear.  
iii. The pre -exposure and the continuous exposure in p rogress warni ng signals shall be easily 
distinguishable from each other. Both signals shall be clearly explained on well sited notices at th e 
boundary. The notice shall  explain the signi ficance of the barrier. Warning signals and notices may be 
combined in the form of illuminated notices.  
iv. In the case of all X -ray app aratus, the warning signals shall  operate at or near the X -ray tube head, 
at the control panel and be clearly recognizable  at the boundary of the area. The pre-exposure and the 
continuous exposure signal s shall operate automatically and the equipment is to be unable to function 
unless they are con nected. Work is to cease if the warning signals are not operating correctly. Interlock 
defeat s witches shall  not be fitted. A device shall be provided to enable the warning signals to  be tested 
while the X -ray head remains de -energized.  
v. In the case of sealed sources, warning lamps are gener ally used which are switched on manually, 
and these are to be in good working order. They shall be positioned so that they are clearly visible to  
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 all persons in the vicinity. The pre -warning ala rm is usually an audible alarm, such as a manually 
operated air horn.  
vi. All warning signals shall be examined and tested on a r egular basis and records shall  be kept of the 
tests undertaken.  
4.2.6 Operating Procedures  
i. At least one designated RPS needs to be present on the site or establishment for the duration of 
any radiographic procedure. The RPS shall be easily contactable by the radiographers undertaking 
the task.  
ii. Written operating procedures shall be drawn up for all X -ray machines and sealed sources by the 
parent establishment of the radiographers, in consultation with their RPA. A copy of the operating 
procedure is to be displayed at the control point during each  such exposure.  
iii. A controlled area shall be set up in accordance wit h the requirements above. It is important that 
control cables are laid out so as to maximize  the distance of the operator from the X -ray tube head. 
The control point is to be, whenever possibl e, outside the controlled area, and where this is so it is 
to be continuously manned thr oughout the whole period of the exposure. At least two classified 
persons are to be employed  on each radiographic exposure, one of these shall be an experienced 
radiographer and both shall  have sufficient knowledge of the actions to be take n in the event of an 
emergency.  
iv. Where the control point is inside the co ntrolled area, operators shall only enter the  controlled area 
to start the exposure, terminate the exposu re or in the event of an emergency. In exceptional 
circumstances where it is necessary for an op erator to operate  the control point inside the controlled 
area the dose rate at the control point is to not exceed 25 μSv/hr.  
v. After setting up the controlled ar ea and before exposure, all persons within the  area not involved 
with the radiography shall leave. A thorough search  of the area shall be conducted with special 
attention being paid to places where personnel  may remain unobserved, such as remote 
compartmen ts and the interior of empty tanks.  
vi. The radiograph ic set-up shall be completed before any se aled source is exposed or X -ray machine 
is energized. No changes to the exposure arrang ements are to be made during an exposure.  
vii. Sufficient guards  shall be posted around the perimeter of the area to pr event entry to the controlled 
area during radiography. Care shall be taken to  ensure that there are no areas where personnel can 
enter unobserved. Where it is not pract icable to provide line of sigh communic ation between guards  
it may be necessary t o provide a voice communication system.  
viii. To ensure that radiation exposure to personnel is kept a s low as reasonably practicable the following 
conditions are to be satisfied:  
a) The useful beam shall  be directed away f rom the control point and all  occupied areas, unless 
these areas are adequately protected by distance or shielding;   
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 b) The beam size and exposure duration shall be kept to the minimum  compatible with obtaining 
a satisfactory radiograph;  
c) Only authorized  person s (these shall be at least classified persons or  people working in 
accordance with written procedures) may enter the controlled area.  
ix. On completion of the radiatio n exposure, the X -ray set shall be switched off, or the  radiation source 
retracted into i ts container. Where a sealed s ource is used, the radiographer shall approach the source 
container using an appropriate dose rate meter and confirm that the source is fully home in its container. 
Where an X -ray set is in use the rad iographer may only enter the controlled area and using a suitable 
radiation monitor ing instrument confirm that the exposur e is terminated.  
x. The movement or manipulation of sealed sources  shall always to be undertaken by remote control. 
Care is to be taken to prevent any part of the b ody coming close to the exposed source. Radiographic 
sources shall never be handled  with bare or gloved hands. All unnecessary movement of sources shall 
be avoided. Sourc es shall only be moved about a unit when they are locked in the shielded position s 
in their co ntainers and the keys have been removed.  
4.2.6 Monitoring Surveys  
A radiation survey record shall be maintained, containing det ails of radiation dose rates at the barrier 
and within controlled areas where persons are ex posed to levels of radiation in excess of 7.5 μSv/hr. 
Radiation survey records shall be maint ained for at least 2 years from the date of the survey, unless 
there is an incident in which case the records are to be kept indefinitely.  
4.2.7 Emergency Procedur es 
i. Contingency plans shall be draw n up by the establishment in consultation with the RPA to cope with 
any foreseeable emergency. A copy of these plans and a set of emergency equipment described in 
these plans shall be carried to each radiographic site. Radiographic sources and conta iners shall be 
designed to withstand severe fires; if a fire occurs the sources are only to be remov ed from the area if 
this can be done without risk to life. If this cannot be done they shall be abandoned and the firefighting 
services informed of thei r presence as soon as possible.  
ii. Special equipment shall be available to deal with emerge ncies such as detached sources, jammed 
sources and damaged containers. The equipment is listed as follows:  
a) Audible alarm monitor;  
b) Personal integrating dosimeter ; 
c) Tongs or CeeVee reachers (1 metre and 2 metre);  
d) Pliers, screwdriver, long -handled wire and bolt cutters;  
e) Adjustable spanner or wrench, rope, hand lamp;   
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 f) Tripod (2 metres high - to hoist end of the proje ction tube to help gravity  return of a detached 
source);  
g) Radiation barrier (quick erect type);  
h) Two bags of lead shot (2 kg each), for Iridium -192 source;  
i) Ten bags of lead or lead shielded semi -cylindrical tunnel for Cobalt -60 sources;  
j) Emergency storage con tainer;  
k) Pouring funnel to suit emergency storage container, for speedy placing of  the source.  
iii. Each person involved in site radiography shall be familiar with the content of these  contingency 
plans. Contingency plans shall be regularly practiced  (and at least annually) using dummy sources etc., 
to ensure that all personnel are a ware of the actions they are to undertake. Records of contingency 
plan exercises (including t he names of personnel involved) shall be kept.  
iv. Contingency plans for site radiography shall be sub mitted to the Health and Safety Executive if 
requested.