Welcome to the ninth edition of the Radiation Protection Adviser.
Readers will be interested to see the articles below, giving brief details of the revised basic safety standards Directive and how we plan to implement it. The article on implementation of the Directive gives a flavour of how we will go about the task - we will keep you informed of the progress in future editions of the newsletter.
For the first time we have included an article about offshore radiography - giving a picture of a different world.
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The Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 1995 (RIDDOR 95) came into effect on 1 April. In general, the regulations simplify what should be reported and how to report it. In addition, for those who undertake work with ionising radiations, these regulations require certain dangerous occurrences involving radiation generators to be reported.
In particular, incidents in which
are notifiable to the relevant enforcing authority (usually HSE). Existing requirements in IRR85 for the notification of other incidents remain unchanged. RIDDOR 95 also requires the employer to send a report to the enforcing authority about certain work-related diseases - these requirements are similar to those in the earlier reporting regulations, RIDDOR 85.
A copy of the leaflet 'Everyone's guide to RIDDOR 95', (HSE 31), can be obtained from HSE Books, see page 1 for address.
Issue 8 included details of the Ionising Radiations Incidents Database (IRID) established under a partnership between HSE, NRPB and the Environment Agency (formerly HM Inspectorate of Pollution).
The first report of IRID has now been agreed, and subject to final clearance, should be published shortly.
The present partners are looking for other organisations to join the partnership or to contribute incident reports to IRID on a confidential basis. Professional bodies in the further education and medical sectors and corporate RPAs will be approached as well as other organisations likely to have been involved in the investigation of radiation incidents; some individual RPAs may also be interested in contributing incident reports to IRID. This will help to ensure that IRID becomes an effective tool in the UK for feeding back experience from radiation accidents and incidents to users of ionising radiations, their advisers and regulators.
Negotiations on the revised Euratom basic safety standards (BSS) Directive were completed and 'political' agreement reached in December 1995. The Directive should be formally adopted soon. The last month of negotiations was frantic but ultimately all the UK's major negotiating objectives were achieved.
Implementation of the BSS Directive
Now the revised Directive has been agreed, the spotlight has moved from negotiation to national implementation. The largest part of this task is revision of IRR85. HSE's current plans are to develop a formal Consultation Document containing draft revised Regulations, ACOP and guidance and to seek approval from HSC for its publication in about a year's time.
At present, HSE is conducting some informal consultation. This is taking two forms - interaction through topic groups and the issue of an informal consultation paper. The purpose of this paper is to seek views on some across-the-board issues, mainly of a structural nature. These views will form the basis of draft proposals for formal consultation.
Our statement to the European Commission on implementing the 1980 BSS Directive referred, in addition to IRR85, to legislation administered by four other Government Departments DoE (registration/disposal), DoH (medicinal products), MAFF (food safety) and DTI (consumer safety). The same will apply this time round. The relevant legislation will need to be reviewed for compliance with the revised Directive and amended where necessary. A new feature this time relates to the exposure of aircrew to cosmic radiation. This will add DoT to the roll-call of Government Departments involved.
The role of Euratom inspectors is to ensure that radioactive material is not diverted to wrong uses. Consequently, they carry out verification visits, with a legal right of entry, checking the returns of nuclear power stations and small users, such as companies which do non-destructive testing. Euratom inspectors are generally outside workers, therefore OWR applies. However, we know that their visits have caused problems because their radiation passbooks do nor reflect the exact requirements of the Outside Workers Directive and , therefore, OWR. The main problem is that there is no space for operators to enter dose estimates.
OWR reg 6(3) requires the operator to ensure that an estimate of the dose received is entered in the outside worker's passbook as soon as reasonably practicable, and reg, 6(4) allows that where the operator no longer has access to the passbook he should give the estimated dose information to the outside undertaking. Discussions have taken place and continue with the Commission to resolve this issue. Pending an outcome to these discussions, operators could either give a copy of the dose estimate to the Euratom inspector or possibly send it to the outside undertaking, which is DGXVII-E, Euratom Safeguards, European Commission, Batiment Cube, Plateau du Kirchberg, L-2920 Luxembourg.
With negotiation of the BSS Directive behind us, we can now make some time to evaluate the OWR. If you have had significant experience of the regulations and would be willing to take part and provide constructive feedback, please contact the Editor.
One of the letters received by the Editor last year asked:
Paragraph 6 of the ACOP supporting OWR explains that, in general, it is safe to assume that all work-related activities are covered unless there is a good reason for believing that the definition of activities does not apply. However, paragraph 12 of the ACOP advises that visitors who happen to be classified and who enter an operator's controlled area, for their own or their employer's information would not usually fulfil the definition of providing a service to the operator and therefore would not be outside workers. Therefore, it is not possible to give a clear cut answer to the first question; each case should be treated on its merits.
If the individual happens to be a classified person and is only obtaining basic information to help estimate costs it is unlikely he needs to be treated as an outside worker. However, if estimation work is undertaken routinely and the individual is a classified person he or she may need to be treated as an outside worker.
As to the second question, the writer makes a valid point. Indeed, HSE has not encouraged the wider use of radiation passbooks for reasons of this kind, although HSE cannot prohibit the practice. Nevertheless, employers who are considering the issue of passbooks to non-classified persons should ask themselves whether this is really necessary - the information in the passbook will be incomplete (e.g. health status). There may be more appropriate means of exchanging information with the site operator e.g. by letter of fax.
The next scientific meeting of the Society for Radiological Protection will take place on 1 October on the topic 'Communicating radiological protection - the professionals, the media, the public'. The meeting will be held in London.
The British Institute of Radiology is organising a meeting on the revised BSS Directive and the Patient Protection Directive in London on 24 June.
In January 1996 HSE published the CIDI statistical summary of dose data for 1994. Copies of the 1994 statistical summary are available from the Editor.
Nuclear density gauges are used to measure the compaction of freshly laid tarmac on road construction sites. The gauges often incorporate a neutron source (typically 1.48 GBq 241Am/Be) and a gamma source (typically 0.3 GBq 137Cs). The gauge is placed in contact with the freshly laid, hot road surface and the amount of back scattered radiation is measured for about one minute. The degree of backscatter can be related to the density of the medium, and the degree of compaction of the surface. Further compaction is provided if necessary. During the measurement the operator stands about two meters away from the gauge to:
The gauge is used in very close proximity to the road rollers and HGV's. The crushing of a gauge by a road roller or other HGV is reasonably foreseeable and there has been a history of such events - an example is given below.
Under regulation 25 IRR85, the employer should assess the hazards likely to arise from any such incident and take all reasonably practicable steps to prevent it from occurring. The employer may also need to draw up a contingency plan under regulation 27 IRR85, setting out steps to identify and limit the consequences of any such incident (eg spread of contamination). Employees will also need information, instruction and training.
Shielding around the sources may become ineffective and the sources themselves may be damaged or detached and lost. Therefore, care of the gauge and effective maintenance are important.
In October 1995 HSE published a free information sheet for managers explaining the requirements for the assessment and recording of doses received by classified persons. Copies are available from the Editor.
We would be interested to receive feedback on this guidance - has it proved useful to employers and employees? If not, why not? Please send comments to the Editor.
Further advice is available in a free information sheet: Ionising Radiation Protection Series No. 3 Portable nuclear moisture/density gauges in the construction industry recently published by HSE. It is aimed at employers of those working with gauges and the self employed. Managers of road building or repair projects may also find it useful. Copies are available from HSE Books.
A company was recently fined heavily in a joint prosecution by the HSE and the Environment Agency (at the time HMIP) following the loss of a nuclear density gauge.
The gauge was 'signed out' of the company 's Head Office store and sent out on site. No record of its whereabouts was kept on site and the firm noticed its loss some months later. It was not reported to the HSE until 14 months later:
The firm was prosecuted under regs 19 and 31 IRR85, and also for a subsidiary offence under Reg 13 when investigations showed that dose records for some of their classified workers were kept by the company themselves and not by an Approved Dosimetry Service.
Two lessons can be learnt from this case:
In October 1995 the European Commission agreed a formal proposal to revise the Patient Protection Directive 84/466/Euratom. The proposal, which was developed by the Commission's group of experts appointed under Article 31 of the Euratom Treaty, has now been considered by the Economic and Social Committee. It is scheduled to go to Council in the Summer with negotiations starting later this year. Department of Health will be leading the negotiations for UK and they intend to consult professional bodies and other interested parties on the draft revision to this directive in the near future.
An incident in which a nuclear density gauge was crushed by a road roller led to a recent HSE prosecution.
After the incident occurred the road roller was driven 100 metres over hot, sticky tarmac and rough ground, and about 0.5 tonnes of limestone chippings poured over the remaining wreckage of the gauge. These actions could have increased risk to personnel in the event of source rupture, source loss, and during attempts at source recovery.
The company's contingency plan stipulated that any vehicle involved in such an incident should not be moved, in order to minimise the dispersal or loss of a source. Also, it stated that the area should be immediately cordoned off at a distance of two metres and people excluded.
An investigation showed that the gauge had not been used in accordance with the company's local rules, nor in compliance with IRR85. A controlled area had not been demarcated or delineated and the gauge had not been continuously supervised. The driver of the road roller had not been given any relevant information or instruction and site management was not aware of what the gauge operator or roller driver should be doing in (a) normal use, and (b) in the event of an accident.
The company was successfully prosecuted under regulation 11(2) IRR85, for failing to supervise the use of the gauge and for failing to provide adequate information, instruction and training about actions required in the event of an accident. The investigation indicated that there were wider ranging management failures which contributed to the incident. Consequently the company was also prosecuted under the Management of Health & Safety at Work Regulations 1992 for failure to make arrangements to control the work.
Lessons can be learned from this incident:
The Radiological Protection Institute of Ireland told us about an incident they have investigated. A manufacturer of animal feeds had taken out of commission a level gauge containing a 137Cs source. They left the gauge, with the source inside, in place on the chute to which it was fitted, but tack welded a protective metal box over it.
Due to the acidic nature of the material being processed, corrosion of the chute became a problem. When dismantling the chute, the fitter noticed that the gauge was missing. An extensive search for the source failed to reveal its whereabouts. Inspectors examining the remains of the chute found that the gauge had been mounted over a hole cut in one side. Since the protective box was still in place at the time the chute was dismantled it was extremely unlikely that anyone had removed the gauge on purpose. It must therefore have fallen into the chute. The question was, how did this happen?
The inspectors believe that, when originally installed, the chute walls were too thick for the gauge to work, so the hole was cut and the gauge mounted on a thinner sheet of metal. Corrosion of the metal caused the mount to weaken and eventually it collapsed inwards, assisted by suction due to the flow of material. Periodically the chute outlet has to be cleared when blocked by solid detritus. A small tipper truck is used to transfer the material removed to a skip.
It is assumed that the gauge was lost in this way, and finished up buried on a municipal waste disposal site. The dose rate close to the source was a few mSv h-1 (the shutter was locked closed), so it would not have exposed anyone involved in the removal and disposal of the device to hazardous radiation levels. The source encapsulation and the gauge housing should ensure that the radioactive contents would not become dispersed.
This incident shows the importance of having satisfactory procedures for accounting for the whereabouts of sources, and for providing suitable storage for disused sources before re-use or ultimate disposal.
We're always interested to hear of incidents like this, and will consider publicising them in this Newsletter. If you have a contribution, please contact the Editor.
HSE has produced criteria for the seven day notification of site radiography, provided by regulation 5(4) IRR85. Inspectors are now applying these criteria to help ensure that companies operating in different parts of the country are treated in the same way by HSE.
There are four main scenarios which require notification by companies which have been served a notice by HSE under regulation 5(4) IRR85:
A site radiography company was recently prosecuted by HSE following an incident in which a radiographer working at a newly constructed chemical plant in the North West received a significant dose to his hands while moving an x-ray set.
Two teams of radiographers were working above ground in close proximity to each other. Having just finished setting up the next exposure a radiographer called down to his work mate stationed at the x-ray control panel to initiate exposure. Unfortunately, the x-ray set had already been switched on and had been generating x-rays for about 45 seconds, giving the radiographer an extremity dose of about 95 mSv.
The control panel operator had heard someone shout down to switch on the x-ray set. He subsequently realised that he had heard this from the other team of radiographers.
This incident illustrates the need for adequate systems of work (including clear and effective means of communication) to restrict exposure. If the person setting up the shot had been in possession of the key from the control panel of the x-ray equipment he would not have been exposed to x-rays.
The HSE took a serious view of this incident and the firm was successfully prosecuted under regulation 6 IRR85.
On 1 April, two new Agencies took over as the regulatory bodies responsible for administering and enforcing the Radioactive Substances Act 1993. The Environment Agency (EA) incorporates HMIP and regulates radioactive substances and radioactive waste in England and Wales; the Scottish Environment Protection Agency (SEPA), took over those responsibilities in Scotland, and incorporates HMIPI. Both Agencies are Non Departmental Public Bodies i.e. they are not part of Government Departments.
Arrangements for authorising disposals of radioactive waste from nuclear licensed sites in England and Wales also changed on 1 April. Previously, HMIP and MAFF (HMIP and the Welsh Office in Wales) were jointly responsible for issuing authorisations for nuclear premises. The Environment Agency has sole responsibility for such authorisations, with MAFF a statutory consultee. No such changes were needed in Scotland where HMIPI was the sole regulator under RSA93. HSE consults the Agencies when considering applications for licences under the Nuclear Installations Act.
The Environment Agency's Head Office is in Bristol, with eight regional offices; SEPA's Head Office is in Stirling with 3 regional offices. Queries should be raised with the regional offices.
Radioactive sources are widely used offshore by specialist contractors for two main purposes -
Logging sources are also generally smaller than those used for radiography and only exposed underground, but there is a potential for incident(s) during transfer of the sources to and from the logging tools, and for loss of sources downhole.
Pipework radiography can be either subsea, on pipelines, installation legs, etc or more commonly "topsides", mainly on process plant. The sources and work methods used are generally similar to those found onshore. Subsea work, however, demands specialist equipment and expertise. X-ray sources are rarely used, except on pipe-laying barges.
The work is often done at night using a permit-to-work obtained from the installation management. Training of the installation's own workers is normally limited to warning them to keep away from barriers marking the edge of a controlled area. In general, the discipline offshore means that the contractors have the area to themselves. The larger installation operators tend to have their own radiography policies and procedures; smaller ones may rely on those of the contractor.
The risks offshore from site radiography are generally the same as those onshore, but the nature of the work and the logistics of offshore working introduce some extra factors. These include:
As most of the radiographers work onshore as well as offshore, it is difficult to get a clear picture of the doses received specifically from offshore radiography. HSE's Offshore Safety Division will be looking increasingly at the way in which client and contractors work together to perform radiography safely, paying particular attention to ensuring that the radiography contractor has sufficient notice from the client to enable proper planning of the work to be carried out.
Issue 7 carried a letter which advocated certification of the safety competence of RPAs and RPSs. In the last issue we included extracts from several readers' letters responding to this suggestion. We have been asked for advice on what it might be reasonable to see in local rules. The following is only intended as a guide.
Please let us know if you agree, disagree or have additional matters that you think should be included.
Occasionally, RPAs may need to help an employer make a special entry application to HSE under reg 13(8) IRR85. Before agreeing to a special entry, HSE must be satisfied that there is reasonable cause to believe that the employee(s) concerned did not receive the recorded dose(s). However, some employers fail to provide convincing arguments to HSE, leading to the application being rejected.
Problems can arise because employers assume it is sufficient to assert that the individual's dosemeter was exposed whilst not being worn e.g. following temporary loss or storage in a 'high dose' area. In these cases, some corroborating evidence is important, e.g. from an exposure reconstruction by the RPA, work records, copies of dose summaries for work colleagues etc. Chromosome aberration analysis of a sample of the individual's blood can also be valuable provided the recorded dose exceeds the limit of detection for this test (typically > 100mSv whole body gamma or x-radiation). To illustrate these points, details are given of two recent applications for special entries in dose records.
A Poor Application
a non-destructive testing contractor applied for special entries for several of its radiographers on the grounds that their TLD were thought to have been accidentally exposed in a mail-room x-ray surveillance device when delivered to site.
The employer stated that the 'high' doses were unprecedented and coincided with the use of the mail-room monitor for the first time. However, no attempt was made to confirm that the mail-room x-ray device was the cause of the problem, for example by setting up test exposures.
Also, the application gave no information about the work schedules of the radiographers. Therefore, there was nothing to show that the doses were unlikely to have been received during the course of the employees' normal work - for NDT work involving the use of large sources, evidence of this kind is crucial.
HSE had little option but to reject this application, even though the mail-room device seemed to provide a possible explanation for the unusual recorded doses.
A Good Application
a fitter working on nuclear plant temporarily lost his dosemeter whilst in an undesignated area; the dosemeter was later recovered but by then, it had been exposed to radiation during some radiography work. The dosemeter was returned to the ADS but, because it was thought to have been lost in an undesignated area, the employer did not mention it had been exposed while not being worn. The measurement of the dose received by the dosemeter was therefore entered in the employee's dose record. When the employer realised that the individual's dose was incorrect an investigation was undertaken, with great thoroughness.
First, a comprehensive exposure 'reconstruction' was conducted. Then the ADS was asked to check the dosemeter worn by the employee for anything unusual about its sensitivity or performance (i.e. glow-curve, contamination and calibration checks). Also, the employer checked the record of doses shown by the personal indicating dosemeters worn daily by the employee for any unusual exposures - none was identified.
HSE approved this application. The employer's 'reconstruction' exercise and the record of doses for the employee's personal indicating dosemeter made it highly unlikely that the dose recorded by the dosemeter had been received by the individual.
In March HSE published revised RADS documents. The basic requirements have been modified to improve clarity and the guidance on specific criteria for approval has now been considerably expanded. Copies have been sent to approved dosimetry services; further copies are available from the Editor.
published on internet 13/11/97