Considerations on a Definition of Nanomaterial for Regulatory Purposes

The recent EU Cosmetic Products Regulation includes a labelling obligation for nanomaterials in the list of ingredients, in order to allow consumers to make a choice. Similar provisions are now being considered for other regulations/directives, e.g. the Novel Foods Regulation. Also the European chemicals legislation REACH may need adjustments to address and control the potential risk of nanomaterials. The introduction of these provisions specific to nanomaterials requires the adoption of a definition of the term "nanomaterial". This need is also acknowledged by the European Parliament which has called for a comprehensive science-based definition in Community legislation. This report reviews and discusses issues and challenges related to a definition of "nanomaterial". It gives a short overview about what may be considered as nanomaterials, their novel properties and applications. The need for a definition of nanomaterial is discussed, and the question of what should be achieved by a definition is addressed. The report gives an overview of definitions by international, national and European institutions, and lists approaches used in European legislation. It summarises the advantages and shortcomings of different elements typically used in available definitions, regarding their applicability in a regulatory context. The following three key elements are identified as being crucial in achieving a single, enforceable definition of nanomaterial: (i) the term "material", (ii) the nanoscale, and (iii) specific nanoscale properties. Material and nanoscale should both preferably be defined precisely in order to ease enforceability. This implies the introduction of precise nanoscale limits and instructions on how such limits can be applied to nanoscale materials with size distributions. Size-derived properties, nanostructured features, nanoscale materials incorporated in a matrix and the origin of the material are also issues to be considered. Key words: nanomaterial, definition, nanoscale, physico-chemical properties, Cosmetic Products Regulation, REACH.JRC.DG.I.5-Nanobioscience

DONA Detector: Further Improvements and Evaluation for Field Applications

The DONA neutron spectrometer concept is based on the measurement of neutron induced activity in a series of small metal disks that have been exposed to a neutron field. The induced activity is measured and the neutron spectrum is calculated using and unfolding technique, based on environmental neutron spectra. The novelty of the approach lies in the concept as such, including usage of carefully selected metal disks arranged in a holder, high performance gamma-ray spectrometry and spectrum unfolding using a library of environmental neutron spectra. This report covers the IRMM exploratory research prolongation project for 2006 and now environmental neutron fields with considerably lower neutron fluence rates are used. The result shows that after further refinement of the detector device and the data evaluation program the detector can very well be used for environmental neutron fluence measurements. Tests were done at PTB, Germany, using their calibrated neutron source and at the MOX fuel fabrication plant Belgonuclearire in Mol, Belgium.JRC.D.4-Isotope measurement

The Recoil Proton Telescope in Non-coincidence Mode for Neutron Fluence Measurements

The paper describes an alternative approach to use the Los Alamos type Recoil Proton Telescope for fluence measurements of mono-energetic neutrons with energies above 1 MeV. Traditionally, this type of detectors are used in a 3-coincidence acquisition mode (proportional counter – proportional counter – end-detector). This study shows that by only using the end-detector and a background reduction method similar results are obtained, but with considerably less complexity in the measurement set-up.JRC.D.5-Neutron physic

Research on Isomer Decay with the NEPTUNE Spectrometer

A new spectrometer has been built at the EC-JRC IRMM to investigate isomer decay in the millisecond range and activation cross sections of isotopes, where isomeric states exist and are populated. The spectrometer is equipped with high-resolution gamma-ray detectors and an ionisation chamber for the measurement of charged particles, e.g., fission fragments. NEPTUNE provides pulsed quasi mono-energetic neutrons at pulse repetition frequencies up to 5 kHz and tuneable neutron pulse widths ranging from 10 µs into the ms-region. For this purpose a beam chopper based on a parallel-plate capacitor has been integrated into the accelerator beam line in order to deflect the charged-particle beam onto a tantalum beam dump. First research has been performed with the NEPTUNE spectrometer dedicated to the shape isomer search in the odd-A uranium isotopes 235U, 237U and 239U. In further experiments the population of long-lived spin isomers was investigated.JRC.D.5-Neutron physic

NEPTUNE - The New Isomer Spectrometer at IRMM

A new spectrometer has been built at the EC-JRC IRMM to investigate isomer decay in the millisecond range and activation cross-sections of isotopes, where isomeric states exist and are populated. The spectrometer uses high-resolution ¿-ray detectors and an ionisation chamber for the measurement of charged particles, e. g. fission fragments. NEPTUNE provides pulsed quasi mono-energetic neutrons at pulse repetition frequencies up to 5 kHz and tuneable neutron pulse widths. For this purpose a beam chopper based on a parallel-plate condenser has been integrated into the accelerator beam-line in order to deflect the charged-particle beam onto a tantalum beam dump. An instrument status report is given together with results from first experiments dedicated to the search for shape isomers in 235,239U performed with the NEPTUNE isomer spectrometer.JRC.D.5-Neutron physic

Validation of a Method for Neutron Dosimetry and Spectrometry Using Neutron Activation of Metal Discs

A technique for neutron dosimetry and spectrometry base don neutron activation of different metal discs has been studied. After exposure to a neutron field the activated radionuclides in the discs are detected using low-level-gamma-ray spectrometry and the neutron spectrum is obtained using a spectrum unfolding technique. In order to validate the method an irradiation was performed in a well-characterized252Cf neutron reference field. Furthermore, the detector was used to determine the neutron fluence rate and spectrum at a storage place for MOX nuclear fuel. The results of the two measurements are reported and discussed.JRC.D.4-Nuclear physic

The New PADC Based Fast Neutron Dosimetry System of the INFN-LNF

At the Radiation Protection Laboratory of the INFN¿Frascati National Laboratories, a new polyallyl diglycol carbonate (PADC) based fast neutron dosimetry system has been established for the routine monitoring of ambient neutron radiation around the 510MeV e+/e- DAØNE collider as well as research activities in the field of neutron dosimetry. The detectors, supplied by Intercast (Parma, Italy), are processed by means of a two-stage chemical etching. The analysis is performed with a new automated reader, developed at the laboratory under the Labview (National Instruments) environment. Taking advantage of a set of automated motion, vision and regulation procedures, this system provides very reproducible, accurate and quick results suitable for both investigation and routine purposes. Moreover, the adoption of a four element configuration combined with a deep study of the background distribution, allows obtaining a minimum detectable ambient dose equivalent as low as 30µSv. This work analyzes the dosimetric performance of the LNF ambient dosemeter as well as the characteristics of the LNF new reading system.JRC.D.5-Neutron physic

New Results on the Neutron-induced Fission Cross-section of 231Pa for Incident Neutron Energies En=0.8 to 3.5 MeV

New results on the neutron-induced fission cross-section of 231Pa in the incident neutron energy range between En = 0.8 and 3.5 MeV are presented. The individual cross-section data are obtained within an uncertainty of less than 5 % and meets the accuracy required by the IAEA in the summary report of the consultant’s meeting on “Assessment of Nuclear Data Needs for Thorium and other Advanced Cycles” from 1999. With the new data the hitherto existing large spread between evaluated data files may be removed.JRC.D.5-Neutron physic

Neutron Field Measurements for Alara Purposes around a Van de Graaff Accelerator Building.

Abstract not availableJRC.D-Institute for Reference Materials and Measurements (Geel

The New Pulsed Mono-Energetic Neutron Source at IRMM at the Shape Isomer Search in 239U

In the frame of the exploratory research initiative of the JRC a new pulsing device has been installed at the Van-de-Graaff of the IRMM to produce pulsed quasi mono-energetic neutron beams in the MeV range. The pulse width may be tuned from 10 mus up to several hundreds of mus with a repetition rate between 1 Hz and 5 kHz. The aim is to study the decay of short-lived activation products between pulses in an essentially neutron-free environment. In a first application the shape isomer in 239U is searched, for which a decay half-life probably much longer than a few tens of mus has been predicted in literature. The new facility will be presented together with first results on the shape-isomer search, and some possible applications will be discussed.JRC.D.5-Neutron physic