Minutes of the Second ASUF Meeting
28 November 2000
National Physical Laboratory
| Participants: | Michel Ceuppens | Canberra Packard, Belgium | |
| Matthew Curtis | VLA | ||
| Peter Danyluk | AWE Aldermaston | ||
| Mike Dolan | AWE Aldermaston | ||
| Jim Desmond | BNFL Geoffrey Schofield Laboratories | ||
| Steve Dunkley | Harwell Instruments | ||
| Terry Gingell | DERA | ||
| George Ham | NRPB | ||
| Trevor Hatt | Perkin Elmer | ||
| Hilary Haywood | AWE Aldermaston | ||
| Simon Jerome | NPL | ||
| Arthur Lally | RTC | ||
| David Lambert | VLA | ||
| John Makepeace | NPL (Chairman) | ||
| Fiona Miller | UKAEA Dounreay | ||
| Darvis Rishehri | NNC WQCL | ||
| Anne Ross | UKAEA Dounreay | ||
| Martin Rushby | AWE Aldermaston | ||
| Bob Sharrock | Urenco | ||
| Robin Treadwell | AWE Aldermaston | ||
| Stephanie Vallet | Harwell Instruments | ||
| Doug Van Cleef | Perkin Elmer | ||
| Mike Woods | NPL | ||
| Simon Woods | NPL (Secretary) | ||
| Alan Young | CEFAS |
1. Chairman’s opening remarks
The chairman welcomed those present. He informed the forum, that NMSPU has agreed that, in future, meetings of the ASUF would be held annually.
2. Minutes of the 1st meeting – 14 April 1999
These were accepted without correction.
3. Actions arising from the minutes
Action 1.1: NPL (Simon Jerome/Julian Dean) to investigate incorporating a survey of MDA techniques into their comparison programme.
Action 1.2: All to review their method of reporting MDAs
Both of these actions will be addressed during the forthcoming environmental comparison. It was noted that a common approach should be used, hence, as well as laboratories using the usual methods, a prescribed formulation should also be given.
One problem that faces those performing alpha spectrometry, as opposed to gamma-ray spectrometry, is that at the MDA level ROI analysis will be used rather than peak fitting and hence the MDA determination is very subjective. This is further complicated if there is spectral degradation present, as then the integration region is poorly known.
When quoting detection limits as part of a tender bid, users are urged to provide enough information on their technique used in order that meaningful comparisons may be carried out.
Action 1.3: NPL (Simon Jerome/Julian Dean) to include sample preparation in discussions at the Environmental Workshop.
Action continues. It was noted that, in particular, the treatment of solid samples should be discussed.
Action 1.4: NPL (Simon Jerome) to raise 242Pu at the next ICRM Meeting (PTB, May 2001).
Action continues. There is a possibility of a workshop between the national laboratories to address the problem.
Action 1.5: NPL (Simon Woods) to arrange discussion meetings between manufacturers and users.
Both Perkin Elmer (EG&G Ortec) and Harwell Instruments (Canberra) were at the forum and would be making presentations later.
Action 1.6: All to inform Simon Woods of problems encountered with decay data.
No reports had been received. It therefore appears that the available decay data is adequate for most purposes. In case problems are encountered, action continues.
4. User discussions
4.1 AlphaVision – user problems
Most people thought that the software worked reasonably well, particularly at the environmental level where ROI analysis, rather than peak fitting, was being used. There was some feeling for a stripped down version of the program. Doug van Cleef (EG&G Oretc) commented that they had done an extensive survey of users and this was the first time they had been asked for less!!
He went on to explain that, if a good peak is present in the spectrum, then peak fitting would be most appropriate approach. NIST had evaluated 100 spectra, each with 1000 counts or more including overlapping peaks. All but 3 analyses gave the correct answer even when the operative had had no software training. He did agree, however, that, for environmental work, peak fitting would not be the primary method of analysis.
4.2 Terms of reference
The terms of reference have provision for a register of UK facilities and services. The subject of “commercial-in-confidence” was raised – a list of services was compiled in the 1970’s but fell into disuse. When attempts were made to resurrect this list post-Chernobyl, problems with confidentiality arose. However, none of those present had any major objection as such a list could be viewed as “free advertising”. However, George Ham did point out that, with the current situation regarding the determination of MDAs, some of the information may be misleading, particularly to an untrained eye.
Action 2.1: NPL (Simon Woods) to issue a proforma asking for available details of UK services and facilities.
Jim Desmond queried whether this register would be duplicating that held by UKAS. It was generally felt that it wouldn’t.
4.3 Air Monitoring
This is a topic that is becoming more of a problem. NPL was in the process of establishing an Air Monitoring Users’ Forum to address issues such as monitoring techniques (including stack monitoring), a/b particulates on filters, bubblers and PAS.
Action 2.2: NPL (John Makepeace) to establish AMUF.
4.4 Traceability
Either a common source of decay data is required or users should ensure that the source of their data is referenced. The preferred option would be to have an extra field in the data tables associated with the various software packages so that this information could be inserted.
5. Manufacturers’ presentations
5.1 Doug van Cleef (EG&G Ortec)
| Topics: | AlphaVision 5.0 | - acquisition control |
| - uncertainties | ||
| - counting facilities | ||
| - spectral manipulation | ||
| - security and traceability |
5.2 Michel Ceupens (Canberra)
| Topics: | Air monitoring | - Ra progeny |
| - PIPs detectors | ||
| - Alpha Analyst | ||
| Web based users discussion group | ||
6. Assessment of uncertainties
It was suggested that a subgroup be formed to look at this topic from a wide ranging viewpoint and produce a list of all uncertainties arising in alpha spectrometry.
Those present expressing and interest in joining the subgroup were:
Mike Woods
Bob Sharrock
George Ham
Robin Treadwell
Terry Gingell
Simon Jerome
Matthew Curtis
Action 2.3: NPL (Simon Woods) to arrange uncertainties subgroup meeting.
7. Concluding discussions
The forum thanked Doug van Cleef and Michel Ceupens for attending and giving their presentations.
Simon Woods
Secretary, ASUF