(formerly The Radiation Protection Adviser) incorporating ADS News
Welcome to issue 25 of Radiation Protection News incorporating ADS News, which aims to clarify areas of concern and update readers on further developments in the field of ionising radiation.
Please send any comments, queries and contributions to firstname.lastname@example.org or Ionising Radiation Policy, Health and Safety Executive, Level 6, North Wing, Rose Court, 2 Southwark Bridge, London SE1 9HS
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It is a fundamental principle of radiation protection, and a requirement
8 of the Ionising Radiations Regulations 1999 that radiation exposures
should be restricted so far as reasonably practicable. But when is it reasonably
practicable to carry out radiography within a shielded enclosure, or to
put it a different way, when is working under site conditions justified?
Since the introduction of the Ionising Radiations Regulations 1985, radiation
exposures of classified persons* have generally fallen, but those received
by industrial radiographers remain high. The main reason for this is likely
to be the exposures received during site radiography when there are reduced
controls in place to restrict exposures.
Radiography enclosures should be designed with appropriate engineering controls, safety features and warning devices to ensure that, so far as reasonably practicable, people cannot receive significant radiation exposures as a result of the work. Site or "open shop" radiography is, by definition, inherently less safe since those in-built controls are not in place and consequently the risks of exposure are greater. If poor working procedures are followed, radiographers have the potential to gain close access to exposed radiation sources during site radiography (the likely reason for the higher recorded exposures), whilst enclosures are designed to prevent this happening. It is always preferable to work in a safer environment, and the question clients and radiography companies have to answer is not is site radiography justified? but more is it possible to do this work in an enclosure? In fact, both points will need answering independently.
It has always been HSE’s view that an item that can be readily loaded onto a vehicle and transported a reasonable distance into a radiography enclosure should be. In those circumstances, site radiography is unlikely to be justified. However, this begs further questions:
There are likely to be financial incentives for transporting work to an
enclosure. For example, enclosure work doesn’t require the attendance
of, and therefore charging for the time spent by "at least two radiographers,
one of whom should be an RPS". Furthermore, the client wouldn’t
feel it necessary to insist that the work was carried out after hours at
a premium rate just so they could clear the site of personnel. Also, as
described earlier, since work inside an enclosure doesn’t present
the same risks of exposure, it is not necessary to notify HSE seven days
And how often is site radiography carried out on the client’s site? HSE receives numerous notifications for repeated attendance by one radiography company at the same client’s site over an extended period. If regular site radiography work is being carried out on their site and movement of items to another premises is considered impracticable, then has the client considered constructing an enclosure? I recently bought a set of clippers because I was fed up of paying my barber £5 a time to shave my head. After a careful start and countless refusals by my wife to go out with me "looking like that", I’d quickly recovered the cost of the purchase and was doing as good a job as the barber. Whilst this somewhat trivialises the issue, radiography companies and their clients should be making similar decisions. Radiography enclosures do not all cost £250K; a ballpark figure regularly quoted by clients during HSE inspections. There are many shapes and sizes of enclosure in use across the country, from converted ISO containers to entire buildings (without necessarily containing large amounts of shielding but of sufficient size that radiation dose rates outside the building are still below 7.5 microsieverts per hour). Where budgets have been quoted for these enclosures, seldom do they approach anywhere near £250K. Where a radiography company or their client is considering building an enclosure, the conditions of the generic authorisation for x-ray work within shielded enclosures (available on this website) should be satisfied.
Radiographers should also be vigilant of small transportable items materialising during genuine site work for radiography "while you’re here mate". Such work cannot be justified under site conditions and the items should be transported to a purpose built enclosure.
Returning to What is a reasonable distance? If work is planned properly, this question may not need to be answered. Clients may have arrangements in place with local radiography companies to routinely carry out site radiography on their premises. The fact that this radiography company doesn’t have an enclosure big enough to fit the item in doesn’t necessarily mean that site radiography is justified. Clients may well have to shop around and make arrangements for enclosure work to be carried out by a different company. If another radiography company has the capability to perform the required exposures inside a suitable enclosure into which the items can be transferred, and is prepared to do so, then any client requesting site radiography on their own premises may have difficulty justifying that decision to HSE. Whilst the onus is on the clients to make appropriate arrangements, some responsibility rests with the radiographers informing potential clients of the requirements of the Ionising Radiations Regulations 1999 and the importance of carrying out work in purpose built enclosures. After all, the radiography company carries the greater burden of compliance with those regulations. A radiography company which carries out site radiography when an enclosure should be used is failing to satisfy the requirements of Regulation 8 to restrict exposures so far as reasonably practicable. In such cases, appropriate enforcement action would be considered by HSE.
If a load is transportable and there is no NDT company nearby, then how far should we reasonably expect a load to be transported? Twenty miles? Thirty miles? Further? The answer to this is not straightforward. Twenty miles across the centre of London is a much more arduous journey than twenty miles along the M5. How well equipped is the company for moving large components on the roads? Companies with well established transport operations are unlikely to find the transportation of items to enclosures inconvenient. Those who have to make new arrangements to transport loads are entitled to make decisions on the practicability of transporting loads based on incurred costs and time taken to ship the loads.
Over all, appropriate restriction of exposure is all about having a positive safety culture. Decisions should not be driven by purely financial reasons, by convenience or, at the other end of the spectrum, the fear of HSE enforcement. All decisions should be supported by a suitable and sufficient risk assessment. If sensible decisions have been made by the radiography company and their clients, the work has been well planned and all risks assessed, and if work is ultimately carried out in appropriate facilities by competent radiography teams, then it is unlikely to fall foul of HSE.
HSE specialist inspectors are based at offices in Luton, Birmingham, Cardiff, Edinburgh and Bootle, and are available to answer any enquiries on these or other matters relating to industrial radiography.
* Exposure data recorded on HSE’s Central Index of Dose Information (CIDI) available via www.hse.gov.uk
It is better to look silly for five minutes, than remain ignorant for life……..
Although I have been an RPA for several years, and during that time have gathered reasonable experience in NDT radiography, I was recently called to advise on an event which I did not recognize as a Reportable Incident.
Difficulty was experienced in retracting an 148 GBq 192 Ir source back into the container. It was recovered from the end of the delivery tube using remote handlers and safely transferred to a recovery pot. The dosimetry recorded 250 microsieverts. The radiation employer was subsequently advised by HSE that this constituted a Reportable Incident under RIDDOR 1995, Schedule 1, para 8 (1b). ( failure to return RAM to safe storage).
It may save other RPAs embarrassment to be reminded of this requirement, and to revise the wider consideration for both gamma (failure to return RAM to safe storage) and X (failure to terminate an exposure ( auto-timer failure). Not only is there a need to consider notification under RIDDOR 1995, but also under IRR99 if significant doses have been recorded.
NRPB have recently completed some work for HSE to review internal doses received from internal intakes of uranium.
Assessment of Internal Doses to Workers Potentially Exposed to Enriched Uranyl Fluoride and Uranium Tetrafluoride - T P Fell, A W Phipps and G N Stradling
This report considers whether internal doses to workers potentially exposed to uranium hexafluoride/uranyl fluoride (UF6/UO2F2), and uranium tetrafluoride (UF4) as a result of routine procedures or accidental intakes could exceed 6 mSv y-1. This will influence the employer's decision to classify them under the Ionising Radiations Regulations 1999, regulation 20(1). Since these compounds are soluble in body fluids, potential chemical toxicity is also discussed briefly. Consideration has been given to enrichments of 5%, 20% and 93% 235U by mass, and exposure by inhalation, ingestion and wound contamination.
It is concluded that chronic or repeated inhalation is the most important route of exposure whereby doses in excess of 6 mSv y-1 could be attained in the absence of respiratory protection and containment of dust-raising procedures. In a reasonable worst case assessment scenario, assuming 20% enrichment and default Type M biokinetics, the annual intake of uranium for a committed effective dose of 6 mSv would be only about 6.5 mg. For low enriched materials, the Occupational Exposure Standard (OES) of 0.2 mg m-3 would be more appropriate for health control.
Details can be found on https://www.gov.uk/health-protection/radiation
In February 2001 the Royal Free Hospital of the Royal Free Hampstead NHS Trust was treating a woman for vaginal/endometrial carcinoma with a ‘manually loaded’ train of caesium-137 sources. Some months after treatment these sources were discovered to be lost and the HSE and Environment Agency were notified.
An extensive investigation into this loss was carried out by General and Specialist Inspectors from the HSE (and a separate investigation was undertaken by the Environment Agency). During the course of this investigation numerous breaches of the Health and Safety at Work etc Act 1974 (HSW Act) and The Ionising Radiations Regulations 1999 (IRR99) were identified. An extensive report into the incident was subsequently produced in September 2001 and statements were taken from various personnel.
An HSE and Environment Agency joint prosecution was agreed and on 16th April 2004 the Royal Free Hampstead NHS Trust pleaded guilty at The City of London Magistrates Court to the following charges:
They were fined a total of £45,000 and ordered to pay costs of £45,619
No proper risk assessment had been performed and source location records, standards of staff supervision, radiation monitoring procedures and local rules were all inadequate. There was also significant concern about the standards of radiological protection training staff performing this procedure had received, the information they had received about a modification to a source train and the standard of advice the Trust had received from an RPA. Last but not least the actual whereabouts of the source train remains unknown to this day.
Although manual loading of sources is becoming increasingly rare, it is important to remember that adequate risk assessments must be performed prior to the use of any radiation source. Staff, including clinicians, must have received proper and adequate training in the safe use of the source and receive refresher training on a regular basis. They should also be properly supervised. Local Rules should be drawn up if the use of the source takes place in or causes the creation of a controlled area and these Local Rules must be brought to the attention of relevant staff. Source accounting records should be adequate enough to identify the loss or theft of a source within a reasonable amount of time and regular radiation monitoring, before, during and after the use of the source should be carried out as a routine.
Through the adoption of these simple radiological protection practices and requirements of the IRR99 losses of the sort that occurred at the Royal Free Hospital can be easily avoided.
Some of you may have heard that HSE is currently looking again at the HSE Statement on radiation protection advisers. Work is still at an early stage but once HSE has developed its proposals there will be an opportunity for everyone to feed into the process. HSE believes that it is an appropriate time to start to review the Statement as it has now been in operation since December 2001.
In due course details of HSE’s proposals will be put on HSE’s ionising radiation webpage inviting comments from all with an interest.
If you want to ensure that you are consulted please send your name, address and e-mail details to: firstname.lastname@example.org
In the meantime HSE would find it useful to have feedback on your experience of going through the RPA certification system. Tell us what you thought about it. This can then be fed into the review process. You can contact us via the e-mail address above or at HSE, Ionising radiations Policy, 6NW Rose Court, 2 Southwark Bridge, London SE1 9HS.
In accordance with the provisions of Part II, Annex 1 of the HSE Statement on radiation protection advisers
HSE has recently recognised the following as RPA Bodies under the Ionising Radiations Regulations 1999:
Dstl Radiological Protection Services
Crescent Road Alverstoke, Gosport, Hants, PO12 2DL
Tel: 02392 768130; Fax: 02392 768150; e-mail: email@example.com
Integrated Radiological Services (IRS) Ltd
Unit 188, Century Building, Tower Street, Brunswick, Business Park, Liverpool L3 4BJ.
Tel:0151 709 6296/4431; Fax:0151 709 8772; e-mail: firstname.lastname@example.org
NDT MainCal Limited
Unit 2 Dale Road, New Mills, High Peak, Derbyshire SK22 4NW
Tel: 01663 742549; Fax: 01663 746837; e-mail: email@example.com
Contact: Simon Wright or Steve Boocock
Contact details for all RPA Bodies recognised by HSE, including the National Radiological Protection Board, are included in HSE’s website.
The revised (11/03) version of the guidance on the criteria of competence for RPA bodies, is available on the web. Though it is presented differently, in terms of content, there is virtually no change from the earlier version.
HSE expects to complete the processing of all adequately prepared applications* that are received by it on or before 30 June 2004 but is not prepared to guarantee this if excessive demand precludes such an outcome.
HSE gives no assurances as to when it would be able to complete the processing of adequately prepared applications* that are received after 30 June 2004.
*An adequately prepared application is one that includes sufficient evidence to enable the HSE Recognition Panel to complete the assessment without further reference to the applicant for additional information (See guidance on the criteria of competence for RPA bodies).
The authors of this report wish to publicise a correction to table 4.1, chapter 4, section 4.3.1.
A dividing line at the top of the table should attribute both the 2nd and 3rd columns (Hp(10) and Hp(0.07) measurements) to the body rather than to hand. The summary and conclusions are not affected by this correction. The web based report has been amended.
Published on the HSE web site 3 June 2004