Minutes of the Twenty-Second IRMF Meeting
Wednesday 7th November 2001
National Physical Laboratory
Present:
Chairman: Martyn Sené, National Physical Laboratory
Secretary: Clare Scott, National Physical Laboratory
There were 29 other members present from 17 establishments, including:
Addenbrooke's Hospital
BAE Systems Marine, Barrow-in-Furness
BNFL, Berkeley
BNFL, Sellafield
Bristol General Hospital
Centronic Ltd
DERA RPS
DRaStaC
National Physical Laboratory
NRPB, Chilton
NRPB Northern Centre
NRPB, Scotland
Nucleonic Calibration Facility
Saint Gobain Crystals and Detectors UK Ltd
St Thomas’s Hospital
Velindre Hospital, Cardiff
Warship Support Agency, Foxhill
Twenty more members, including some from a further fifteen establishments had sent apologies.
AGENDA ITEMS
Gamma-radiation Monitoring Comparison
Duncan McClure (NRPB, Chilton) summarised the format of the present exercise. In particular there would not be a secondary standard or ionisation chamber type of instrument and no check source would be circulated. Uncertainty budgets would be requested in order to encourage labs to think more about their uncertainties and also to provide extra information to aid the analysis of results.
The instruments chosen for the exercise were the Electra with MC20 probe, the Mini-Rad 1000 and the EPD Mk2. Participants will be able to choose whether to calibrate the personal dosemeter on-phantom or off-phantom.
The protocol for the exercise will be circulated by e-mail. The measurement phase began in September and 4 of the 15 participating laboratories had completed their measurements to date. The final report was anticipated in Winter 2002.
Neutron Monitoring Comparison
Vic Lewis (NPL) reported that the Working Group had agreed to use a Mark 7 NRM (spherical moderator) and an NM2 (cylindrical moderator). All but one participant would calibrate the two monitors in fields produced by 241Am-Be and 252Cf sources; NPL and the final participant would calibrate the monitors in 2.7 MeV monoenergetic neutron fields.
One laboratory had completed their measurements to date. Measurements involving radionuclide fields were expected to be completed by March 2002 and the accelerator field measurements by the end of April 2002. The report on the exercise was anticipated in September 2002.
Comparison of Surface Contamination Monitoring
Clare Scott (NPL) reported that all participant data had now been received and the final analysis could be done. A workshop would be held after the main IRMF meeting to give participants the opportunity to view and discuss the raw data for the first time. It was hoped the workshop would allow the participants to share their experiences. A full report on the comparison would be published in December the near future.
Good Practice Guide 30, Practical Radiation Monitoring
Mike Woods (NPL) reported that a draft of the Guide had been made publicly available for comments. Following a presentation about the Guide made to AURPO (the Association of University Radiation Protection Officers), more illustrations and worked examples were requested. A final draft is expected in March 2002, this has been slightly delayed to allow inclusion of the additional worked examples.
Good Practice Guide 29, The Examination, Testing and Calibration of Installed Radiological Protection Instrumentation
Max Pottinger (BNFL, Berkeley) reported that this Guide was finished and was undergoing approval processes at NPL at the time of the IRMF meeting. Max reminded the meeting that this Guide covers installed gamma monitors and installed contamination monitors but not waste clearance monitors.
Click here to download NPL's GPG 29
Good Practice Guide 34, Radiometric Non-Destructive Assay
Vic Lewis (NPL) reported that production of GPG 34 had been initiated at the request of the Nuclear Installations Inspectorate (NII) and that the NPL secretariat was sponsored by HSE and four other organisations; the IRMF was not involved. The GPG described NDA methods, their limitations and calibration, uncertainties, performance demonstration, routine and maintenance testing and other aspects of quality assurance. It was aimed at applications in the nuclear industry such as criticality control, safeguards and the assessment of radioactivity in wastes, but was not intended to cover radiation protection and environmental monitoring.
It was intended to put a consultation draft of this Guide on the NPL website inviting comment from industry in general during 2002. It would be free to download. A final version, incorporating comments reported by the user community on the experience gained working with the guide, would be published at the end of 2002.
Secretary’s note: GPG 34 is available here
Good Practice Guide on The Treatment of Uncertainty in Radiological Measurement
Vic Lewis (NPL) described the aims, scope and progress of the GPG on uncertainties. The first section, a summary of the principles contained in M3003, had been completed. Four other sections contained examples of uncertainty budgets, along with discussion of the components, for radioactivity measurement, surface contamination monitoring, neutron area monitoring and photon dosimetry. Progress in the last three areas was linked to the uncertainty budgets that had been produced for the IRMF comparison exercises in those areas, and also to budgets produced for accreditation purposes. These sections needed to be finalised, incorporating the experience gained in the recent comparisons.
Mike Woods (NPL) thought that the radioactivity example, which covered the measurement of radon, needed to be reconsidered because it was too complex and perhaps inappropriate. It was hoped that first drafts of all sections, with the exception of that on radioactivity, would be produced by the end of December. These would then have to undergo peer review by the Working Group which should be reconvened with new members replacing those who had left.
Several members emphasised the urgent need to produce guidance for the widely used areas, if necessary leaving out the section on radioactivity. More sections could be added at a review of the Guide in about five years time. Consideration should be given to publishing consultation drafts of the GPG and of proposed additional sections on the NPL website in order to make the guidance available as soon as possible.
Policy on Production of Good Practice Guides in Ionising Radiation Metrology
Vic Lewis (NPL) gave a résumé of the draft procedure document covering the production of GPGs in the area of ionising radiation measurement. The document dealt with the setting up, responsibilities and functions of the Working Group, the drafting and peer review of the various versions, consultation by the user community, the review process and the charge for copies. A recommendation to review Guides at least every five years would be made. The policy document would be issued to GPG Working Groups and their chairs to show them what is expected.
Martyn Sené (NPL) reported that he had raised the matter of pricing GPGs with both NPL and DTI. Both had recognised the need for as wide a circulation as possible and acknowledged the need to recognise the contribution made by other organisations. The DTI stated that the NMS subsidised the cost of production but not the cost of printing such Guides (note this funding had not been received for GPG 14). It did not wish GPGs to be free because this would reduce the perceived value. NPL wished to recover the costs of printing and distribution. The standard price of GPGs published to date appeared to be £25 per copy, however, NPL actually made a loss by selling them at this price. Martyn Sené proposed that free copies should be given to organisations that had contributed to the GPG and that the two Guides to be published in the near future (GPG 29 and GPG 30) should be available to others at £15 per copy; this was under review with DTI.
Max Pottinger (BNFL, Berkeley) reported that there was a feeling in the nuclear industry that the IRMF should be approached to recommend the production of an urgently needed GPG on monitoring for the clearance of contaminated waste (this was not covered by GPG 34). The nuclear industry would approach universities and hospitals to get their views and their experience of complying with the regulations in this area. Such a GPG would fit in well with other GPGs in the ionising radiation area.
Click here to download NPL's GPG 14
Terms of Reference
It was decided that the ToR should be revised to reflect the evolution of the activities of the IRMF over the last ten years. It was made clear that the ToR will not restrict the activities of the IRMF in any way; their revision should be considered an opportunity to have them reflect more closely the work that has been undertaken recently.
The Chairman proposed the additional aim to encourage the development and dissemination of good practice in ionising radiation metrology and to specifically mention the organisation of comparison exercises and promotion of the production of GPGs for appropriate areas relating to ionising radiation measurement amongst the activities of the IRMF. The revised ToR can be found at the end of these minutes.
Forthcoming Events
The following meetings and courses were announced:
- Uncertainties Workshop on Radiochemical Analysis at NPL, 12-14 November 2001 (contact Dagmara Tyler 020 8943 6085)
- Nuclear Instrumentation Calibration Course at HMS Sultan, 19 Nov – 7 December 2001 (contact Jon Taylor 023 9254 6051)
- Gamma-ray Spectrometry Users Forum at NPL, 20 November 2001 (contact Simon Woods 020 8943 6424)
- Environmental Comparison Workshop at NPL, 9 January 2002 (contact Julian Dean 020 8943 6278)
- Practical Course in Reference Dosimetry at NPL, 28 - 30 January 2002 (contactRebecca Nutbrown 020 8943 6473)
- Radionuclide Calibrator Users Forum at NPL, 31 January 2002 (contact Michaela Baker 020 8943 6579)
- Radiotherapy Standards Users Meeting at NPL, provisionally June 2002 (contact Rebecca Nutbrown 020 8943 6473)
- Neutron Users Club, September 2002 (contact Peter Kolkowski 020 8943 6855)
- Liquid Scintillation Users Forum September 2002 (contact Andrea Woodman 020 8943 6435)
- Air Monitoring Users Group September 2002 (contact John Makepeace 020 8943 6480)
- Uncertainties Workshop on Gamma Spectrometry 2002 (contact Dagmara Tyler 020 8943 6085)
(Note: NPL email addresses are in the form first name.lastname@npl.co.uk)
Desiccants
Jan Easterbrook and Duncan McClure (NRPB) reported that they had recently needed to seek a new supplier of desiccants for use in ion chamber instruments. Cobalt chloride, the chemical commonly used as an indicator in silica gel, has been reclassified as a Class 2 Carcinogen. It is now considered to be toxic and will be subject to tighter disposal requirements under the Special Waste Regulations 1996.
At NRPB it has been necessary to source alternative chemicals for this purpose and a new supplier has been identified. GeeJay Chemicals Ltd (contact details below) supply non-toxic desiccants with a variety of possible colour changes, the most dramatic of which is orange – green. NRPB had sachets made to specially fit into RO2 and RO10 instruments which cost about 25 pence each.
GeeJay Chemicals Ltd
16 Gosforth Close
Middlefield Industrial Estate
Sandy
SG19 1RB
tel. 01767 682774
fax. 01767 692409
www.geejaychemicals.co.uk
Further information can also be found at: www.envirogel.co.uk
Air Monitoring Group Feedback
John Makepeace reported that the Air Monitoring Users Group (AMUG), had been established partly as a result of requests by IRMF members. The AMUG had held its first meeting on 20 September and was attended by 37 people representing 23 organisations with an additional 25 members requesting future information. Since that meeting, the AMUG had been approached by a similar group, chaired by Mr Overhoff in the US, to see whether information could be exchanged between the groups and if there was potential for future cooperation.
Invited talks had been given by Max Pottinger (Particulates-in-Air Monitoring) and Bob Otlett (Air Sampling Using Dry Bed Absorbers). Other topics discussed included self-absorption corrections, measurement uncertainties, radon compensation and stack sampling modelling. An invited talk from the National Engineering Laboratory on the measurement of flow rates was being considered for the next meeting.
The diversity of the activities of the group members was very wide. In order to focus priorities for future meetings, all members will be sent a questionnaire asking what areas of their work require additional advice or guidance. NPL will also set up an e-mail distribution list for members to raise issues for discussion between the yearly meetings. Further information regarding the AMUG can be found at: http://www.npl.co.uk/armug/ or obtained from John Makepeace (020 8943 6480).
HSE Response to Source Movement Difficulties
At the IRMF meeting on 2 May 2001 John Simpson (RWE Nukem), raised the issue of source movements on NII licensed sites. Difficulties were being experienced with the level of administration required to move relatively small quantities of radioactive material between sites for the purpose of testing radiation protection instrumentation. It was agreed that the IRMF would approach the HSE on this matter and request some clarification on appropriate levels of control.
The Secretary reported that the HSE had been approached to provide a speaker to attend the present meeting however, it was agreed that while they were happy to provide clarification, more detailed information regarding the problems encountered was needed before they were able to fully respond. Dr Patrick Stephen (contact details below) has agreed to either attend or prepare a statement for presentation on his behalf at a future meeting. Members are requested to send details of their specific experiences to Patrick Stephen so that he can respond to the particular issues arising.
Dr Patrick M S Stephen
HM Principal Nuclear Inspector
Health & Safety Executive
Magdalen House
Trinity Road
BOOTLE
MERSEYSIDE
LG20 3QZ
tel 0151 9514834
fax 0151 9513942
patrick.stephen@hse.gsi.gov.uk
NPL NMS Programme and PFI Update
The Chairman announced that the new NPL National Measurement System programme had been approved by the Science Minister Lord Sainsbury and had begun on 1 October 2001. He thanked the members of IRMF for their input to the formulation of the programme. Details of the programme content would be featured on the DTI website at the following address: www.dti.gov.uk/nms/prog/old/ir.pdf A document giving an overview of the programme would also be sent to all IRMF members when it is published. Invitations to tender for the competitively tendered projects in the programme will be posted on the DTI website.
The Chairman reported the current situation with regard to the move of much of the Centre for Ionising Radiation Metrology into the new building. The Chemical Dosimetry section had moved and been successfully recommissioned. In terms of X-ray dosimetry, a Protection Level calibration period was underway which will be followed by a Diagnostic and Mammographic calibration period and then a Radiotherapy calibration cycle beginning in February 2002. The Radioactivity measurement services had been worst affected by the move but these services were now gradually coming on-line. The gas-counting facilities were due to move during 2002 so some disruption to this service was expected next year.
Due primarily to problems with the new building, recommissioning of equipment had not been as rapid as anticipated. The Chairman offered apologies to members who had been unable to access the usual calibration services.
Next Meeting
The next meeting will take place on Wednesday 15 May 2002, in the Auditorium in Module 16 at NPL (the new building). The meeting will commence at 10.30 am as usual, with coffee served from 10.00 am. After the main meeting there will be an opportunity to visit the new laboratory facilities in Module 6.
Clare Lee (neé Scott)
Secretary, IRMF
Centre for Ionising Radiation Metrology, NPL
The above report is a summary of the minutes of the meeting. The minutes have been sent to all members attending the meeting and to those who had previously expressed an interest in the activities of the IRMF.
Anyone with an interest in the metrology of ionising radiation who wishes to attend or learn more about IRMF meetings and activities should contact the Secretary.
Ionising Radiations Metrology Forum - IRMF
TERMS OF REFERENCE
Aims
The NMS Ionising Radiation Metrology Forum exists for the benefit of UK establishments and organisations required to comply with the requirements of current ionising radiation legislation.
The forum aims to:
- encourage the development and dissemination of good practice in ionising radiation measurement;
- provide an opportunity for the exchange of information about available UK calibration and testing facilities and the efficient use of those facilities.
Activities
The Forum shall:
- hold regular meetings to discuss matters of common interest relating to ionising radiation calibration and measurement, including national and international specification standards;
- encourage good practice in ionising radiation measurements (including traceability to national standards) by all appropriate and practical means;
- organise comparison exercises in appropriate areas of ionising radiation measurement;
- promote the drawing-up and production of measurement good practice guides, codes of practice and other guidance material for appropriate areas of ionising radiation measurement;
- maintain and disseminate a register of UK ionising radiation calibration and testing facilities and services.
Membership
Members shall be representatives of UK establishments or organisations actively involved in calibration or measurements in the field of ionising radiation and radionuclide metrology, together with representatives of manufacturers of instruments and artefacts pertaining to such measurements.
Management
The Forum shall be managed by NPL, assisted by advisory committees drawn from and established according to the wishes of the members. Those responsible for the management of the IRMF shall take due account of views of the members. NPL shall provide the Chairman and Secretary of the IRMF.
Fees
There shall be no annual subscription but NPL shall reserve the right to make a charge for organising meetings, producing reports and providing services.
Liability
Neither NPL nor the IRMF nor any member thereof shall be responsible for any consequence arising from the activities of the IRMF.
NPL makes no warranty or representation that the use of any information arising from the IRMF will not infringe the rights of third parties but, if NPL staff whilst engaged on the IRMF become aware of any apparent infringement, NPL will inform the member.
NPL accepts no responsibility for the use made of any information from the running of the IRMF either by a member or by any third party who has obtained any of the said information, directly or indirectly from the member, except to the extent that NPL can be shown to have been negligent in providing such information.
Revised December 2001