Main Research Area and International
Activities of the Radionuclide Metrology
Laboratory from IFIN-HH
“Horia Hulubei” National Institute of Research and
Development for Physics and Nuclear Engineering,
IFIN-HH, Bucharest, Romania
Second workshop for radioactive Decay Data Evaluators,
Bucharest, Romania, May 12 – 14, 2008
Subjects to be treated
• General presentation of the Radionuclide
Metrology Laboratory (RML)
• Main research areas
• International cooperation of RML
•IFIN-HH was founded, under the name of
“Institute for Atomic Physics”, in 1949.
•Name IFIN was given in 1977, what became
IFIN-HH (Horia Hulubei) in 1996.
• Radionuclide Metrology Laboratory
(RML) was created in early sixties.
The founder is Dr. Enric Leon Grigorescu.
Official Status of the Laboratory
• Absolute (primary) standardization in the field.
• 2005-Protocol, National Metrology Institute (NMI) -Romanian
Bureau of Legal Metrology (BRML) and IFIN-HH:
- IFIN-HH - owner of the Primary Standard of Activity Unit
(Becquerel) and derived units
- BRML designated IFIN-HH: participant in International
Committee for Weights and Measures - Mutual Recognition
Arrangement (CIPM-MRA) ionizing radiations, CIPM-MRA, Annex
- BRML appointed IFIN-HH: representative in the Technical
Committee for Ionizing Radiations (IR-TC) of EURAMET
• BRML authorizes RML for legal metrology activities and
attests it , as a calibration laboratory
Infrastructure and personnel
RML- part of the IFIN-HH Radioisotope Department (RD)
- Facilities for safe operation of sealed and open radioactive
sources: radiochemistry laboratory, a balance room, two
measurement laboratories, auxiliary rooms;
- Separation from the RD crossing activities. Climatic regime
and radiation background control-recently improved.
- As a part of IFIN-HH, RML has access to all the available
facilities, library, computing and communication network
•RML Staff: 5 permanent and 1 associate members
2 PhD, 1 PhD student, 1 Scientific researcher, 1 young physicists,
Thanks are due to Dr. E.L.Grigorescu, who retired.
Main research areas
• Methods and equipment for absolute
• Methods and equipment for spectrometry and
for relative standardization
• Methods and equipment for preparation of
• Metrology services and assurance of
4πPC-γ coincidence method
Standardization of radionuclides emitting several coincident
radiations and of pure beta emitters, by the tracing method.
- First system, manually operated, constructed during sixties,
contains a home made Proportional Counter (PC) - flow type,
pure methane , and a NaI(Tl) detector.
-Electronics is NIM modular of types Nuclear Enterprises and
The method and equipment were verified in
X, gamma - X, gamma coincidence detection block -
two thin NaI(Tl) detectors - standardization of 125
M. Sahagia et al. Appl.Radiat.Isot.3986/2008, under print.
Main Romanian contribution
in the development
of the method
(i) Dead time and coincidence resolution time corrections,
E.L. Grigorescu, Mesucora Congress, Paris 1963;
(ii) Measurement of beta, electron capture-gamma emitters,
by the efficiency extrapolation:
E.L. Grigorescu, Nucl.Instrum.Meth. 112(1973)151 ;
E.L.Grigorescu, et al. Nucl. Instr.and Meth A369(1996) 414-
420 and subsequent papers;
(iii) Efficiency tracer for pure beta emitters and
extrapolation for emitters with transition to the ground
level. M.Sahagia, Marianske Lazne , Symp., 1979, Proc., 2/5,
pp.180-187, and followings;
(iv) Standardization of special radionuclides, 99m
M.Sahagia, Appl.Radiat.Isot. 64(2006)1234-1237.
New coincidence system
• The Research project, supported - Romanian National
Authority for Scientific Research (ANCS), 2006-2008,
• New 4πPC-γ coincidence system: a Proportional
Counter, two NaI(Tl) detectors and new electronic
modules, ORTEC type or home - IFIN-HH made,
operated in a semi automatic regime - constructed, is
under testing :
C.Ivan et al. IFIN-HH Internal Rep. 2007.
• Thanks are due to the Bureau International des Poids
et Mesures (BIPM), ENEA (Italy) and Laboratoire
National “Henri Becquerel” (LNHB) from CEA-
Saclay, France, for their help in designing the new
Liquid Scintillation Counting
•Liquid Scintillation Counter, principle of the Triple to
Double Coincidence Ratio (LSC-TDCR):
Detection block with three photomultipliers and associated
• Contribution of the LNHB-France and RC-Poland
LSC-TDCR method implemented, and the system used
for standardization of : H-3, C-14, P-32, Ni-63, Sr-89, Tl-
204, Am-241, Cs-137, Fe-55
•Method and system - verified by bilateral or key
A.C. Razdolescu and P. Cassette, Appl. Radiat. Isot. 60 (2004)
A.C. Razdolescu, et al, Appl. Radiat. Isot. 64 (2006) 1510-1514.
ANCS project – LSC improvements under way:
(i) New photomultipliers, type Burle 8850
(ii) A new detection block with 6 Channel
(iii) A NaI(Tl) probe for the application of the
4πLS-γ coincidence method.
(iv) The LabVIEW operation software - under
Methods and equipment for spectrometry and
for relative standardization
• Spectrometric methods
• Equipment and methods for relative
- Traditional work: GeHP gamma-spectrometer of the RD
- Contribution in development of the spectrometry method:
(i) Use of the coincidence and Compton suppression
anticoincidence for the low level activity measurements.
E.L.Grigorescu, Nucl.Instrum.Meth. A 369 (1996) 574-577;
A. Luca et al., Appl. Radiat. Isot. 53 (2000) 221-224;
E.L. Grigorescu et al., Appl. Radiat.Isot. 61 (2004) 191-195;
(ii) Studies on the shape of the gamma-ray background under
the total absorption peaks,
A.Luca et al., Appl.Radiat.Isot. 60 (2004) 233-237;
(iii) Measurement of the X- and gamma-rays emission intensities
for Zn-65, Sb-124
M.M.Be, ICRM2005, Appl.Radiat.Isot. 64 (2006)1396;
Content of the system
Three detection blocks:
(i)Gamma-ray detector: coaxial HPGe type,
ORTEC model GEM-25P4, relative efficiency 30% (60
resolution 0.62 keV for 122 keV and 1.67 keV at 1333 keV;
energy interval: 30 keV - 3 MeV. Shield: old lead, copper and
a 1 mm thick tin foil - under construction
(ii) X-ray detector - Si(Li), CANBERRA : energy interval 1
keV-50 keV, resolution 166 eV at 5.9 keV
(iii) Alpha spectrometry chamber - surface barrier
silicon detector, and vacuum system.
All the three detection blocks are compatible (or adapted) to
the analysis system, ORTEC, consisting from a digital
spectrometer, connected to a personal computer.
Software facilities :
ORTEC GammaVision-32 (Model A66-B32), version
6.01, Advanced Measurement Technology, Inc.
ORTEC MAESTRO-32 (Model A65-B32), version 6.06,
Advanced Measurement Technology, Inc. (AMETEK),
GESPECOR, Romanian (Prof. O. Sima) - German (Dr.
D. Arnold) - calculation of coincidence summing
corrections and transfer of efficiency calibration between
various geometries and matrices.
Equipment and methods for relative
Well-type ionization ionization chamber
Transfer instrument, for secondary standardization
of radioactive sources and solutions.
Calibration of the chamber.
Calibration figures were assigned for Various Gamma
emitters and various geometries
(i)High activity sealed sources: certified by other
producers - 241
(ii)Solutions vials: 2ml , PTB, Germany; 3.6 ml, BIPM -
SIR; 5 ml , for radiopharmaceuticals; response is
dependent of the volume of solution, mainly for low
energy gamma-rays emitters.
Calibration for solutions
•Calibration with solutions absolutely standardized in RML by
4πPC-γ coincidence method , for 17 radionuclides: 54
Uncertainty, U, for k = 2: U < 1.0% ( 2.1% for 99m
•10 radionuclides: 54
verified in Key comparisons. RML values compared with calibration
figures assigned, according he Key Comparison Reference Values
(KCRV). Maximum difference: 241
•Calibration performed in 2001 at PTB, Germany, by Dr. H.
Schrader, A.Luca and Al. Druker (NMI), using PTB - 2ml vials with
standard solutions, for 19 radionuclides, 11 being common. PTB -
IFIN-HH comparison : results agreed within uncertainties.
•Special attention for 131
I , Sahagia et al. ARI 66(2008)539-544
Improvement of the electrometric system
of the chamber
• Traditional electrometric system : a set of 0.1 nF, 1nF, 10
nF and 100 nF capacitors.
- Separate calibration figures, expressed in, mV s-1
the capacitors, had to be determined, to be used for various
• Since 2006, an electrometer type Keithley 6517A has
- Parallel registrations, with both electrometers, and precise
determination of the capacitors values - performed .
- The capacitor , 1 nF - value was determined with an
uncertainty uc = 0.15%.
• The calibration figures were transferred to the new
units, pA MBq-1
Large area multiwire, sealed proportional counter
• Used for large surface alpha and beta sources used for
measurement of surface contamination.
• Calibration - performed in terms of activity and particle
emission rate in 2πsr geometry.
- calibration in activity was performed by using standard
sources, gravimetrically prepared from 147
- emission rate calibration is made using sets of sources
measured directly in the upper half of the proportional counter.
- response values - determined for various source dimensions,
up to 250 mm x 250 mm.
M.Sahagia et al. Proceedings, IRPA 9 Congress, 1996, vol 3,
pp.34-36 Vienna, Austria
Methods and Equipment for preparation
of radioactive sources
• Sources and solutions for absolute (primary) standardization
- Radioactive solutions and gravimetric dilutions for other solutions.
- Sources for absolute standardization: solid VYNS sources for coincidence
method and LSC vials.
- Traditional work: a METTLER M5 micro and an analytical balance.
- Recent purchase: a set of METTLER TOLEDO certified balances, types:
MX/M (micro) and XS204/M.
• Radioactive standards for users
- various types of radioactive solutions
- solid radioactive sources, covering the main part of Romanian necessities:
alpha spectrometric sources,
large area beta sources
sets of gamma sources, of types: (i) point sources; (II)
volume solid sources, with matrices: water equivalent, soil, zeolite for
various volume samples measurement.
M.Sahagia et al. ICRM1991, Nucl.Instr. And Meth. A312(1992)236-239
Metrology services and assurance of traceability:
• Organization of national comparisons
- Environmental type, mononuclide samples, 2 comparisons, 134
M.Sahagia et al. Nucl. Instr. And Meth. A339(1994)38-42
- Radiopharmaceuticals: 131
I (1994 and 2007), 57
Co (1998), 99m
Tc (1998 and
M.Sahagia et al. Proceedings, IRPA9 Congress, 1996, Vienna, Vol.3 pp.497-499
• Metrology services
As a B RML authorized and attested laboratory, RML performs
- legal metrological check and calibration of equipment
- standardizes radioactive sources for users (RML products, or imported).
• Accreditation by the national body, RENAR.
- whole documentation for accreditation - submitted to RENAR
- pre-assessment evaluation , according to EN ISO/IEC 17025-2005, by Mike J
Woods, IRMC Ltd., U.K.
- RENAR evaluation of the documents and implementation - this year.
- process is under way, with the accomplishment of corrective actions.
• Participation at international comparisons
for absolute and relative standardization
• Membership in international organizations
• Bilateral and multilateral projects
Participation at international comparisons for
absolute and relative standardization
• BIPM comparisons since 1962 - 60
• Adoption of the CIPM-MRA (Mutual Recognition
Arrangement) and establishment of the Annex B, Key
Comparison Data Base (KCDB), RML is part of the
• Key comparisons registrations:
(i) BIPM.RI(II)-K1: 110m
(ii) CCRI(II)-K2: 241
(iii) EUROMET RI(II)-K2: 169
Yb , 124
Sb (under analysis)
• Supplementary comparisons, organized by the IAEA
CCRI(II)-S4 “Radionuclides activity measurement in
environmental samples of water, soil and grass” (2006);
CCRI(II)-S5 “TENORM” (2007); CCRI(II)-S6 - 131
Co (planned 2008)
Conclusions from comparisons
• Classification of results:
- Very satisfactory results- our result being considered for the calculation
of the KC Reference Value (KCRV), 60
I ( SIR 2007-
2009 approval); results with small deviation from the mean: 54
- Good results, registered in KCDB, but not in KCRV (134
- Not satisfactory - 125
I. We identified the error sources and developed a
new, coincidence, standardization method.
• The program allowed us:
- to validate our methods for absolute and relative standardization,
- to establish the equivalence of the primary Romanian Activity standards
at the level of the CIPM-MRA,
- to promote 37 Calibration and Measurement Capability (CMC) files,
for radioactivity, which were approved by all Regional Metrology
Membership in international organizations
•IFIN-HH - Member of the International Committee for
Radionuclide Metrology (ICRM) since 1980
- RML participated regularly, starting with 1991, at ICRM conferences
and presented scientific papers.
- Dr. Enric Leon Grigorescu served as ICRM - Vicepresident, during
-Dr. Maria Sahagia is in the nominating commission, 2001-2009.
Recognizing the active participation in international comparisons and
RML publication list
• The Consultative Committee for Ionizing Radiations, Section
Measurement of Radionuclides [CIPM-CCRI(II)], accepted IFIN-
HH, as a full member, in 2004,
besides other 18 Metrology Institutes and 8 Observers
In this quality, we presented reports at the 2005 and 2007 meetings
and updated regularly the publication list.
Bilateral and multilateral collaboration
EC of Excellence – IDRANAP
• Collaboration with LNHB-France
Collaboration Agreement, concluded by the CEA-DIMRI (DETECS)/ LNHB
– France and IFIN-HH, 1993, in force until 2010
Very fruitful, all IFIN-HH, RML members worked in the LNHB and French
colleagues in IFIN-HH.
Common papers published:
-X and gamma-ray spectrometry:
A. Luca et al., Appl.Radiat.Isot. 52(2000)481-486, 56(2002)173-180,
58(2003)607-610; Appl.Radiat.Isot. 60(2004)233-237
A.C. Razdolescu and P. Cassette, Appl.Radiat.Isot. 60(2004)493-498;
-gas and LSC counting:
D. Stanga et. al., Appl.Radiat.Isot. 64(2006)1203-1206, P. Cassette, M. Sahagia et
al., Appl.Radiat.Isot. 64(2006)1465-1470;
-LSC-TDCR using channel photomultipliers:
C. Ivan et al., ICRM2007, Capetown, SA, Appl.Radiat.Isot. ref 4007.
New directions developed at RML:
LSC-TDCR method, Tritium gas measurement, High performance gamma-
ray spectrometry and Nuclear Decay Data Evaluation, Radon
standardization, Use of CPMs for LSC-TDCR.
• IFIN-HH, RML benefited of a common
calibration of the CENTRONIC IG12/20A
Ionization Chamber at PTB-Germany, in 2001
• Collaboration with ENEA- Italy was
accomplished by three ENEA fellowships, 2001-
2002: Source preparation, Coincidence counting,
Surface sources measurement.
• European Commission’s Center of Excellence
InterDisciplinary Research and Applications Based on
Nuclear and Atomic Physics (IDRANAP), Contr. ICA1-
- Radionuclide Metrology Laboratory participated as the WP 7
- RML members worked mainly at LNHB, on thematics:
Decay Data evaluation, LSC-TDCR, Gas counting.
- Colleagues from LNHB-France, RC POLATOM-Poland, ENEA-Italy,
Institute of Hungarian Academy -Center Debrecen, worked in RML, in
the fields: LSC-TDCR, Coincidence counting, Positron emitters
obtaining and standardization.
- RML members and his visitors had an important scientific
contribution at the Conference: Applications of High Precision
Atomic and Nuclear Methods (HIPAN 2002 ) Neptun, Romania,
9 participants from WP7, 9 papers presented-published in Conference
Proceedings, Romanian Academy Editor, 2005
Multilateral Projects - continued
• International Atomic Energy Agency (IAEA)
Coordinated Research Projects (IAEA-CRP)
- CRP E2.10.05 “Harmonization of quality practices for nuclear medicine
radioactivity measurements” Contract ROM/12921/ 2004-2008
“Assurance of traceability, IAEA, IFIN-HH, hospitals, for nuclear medicine
- Participated at : two international comparisons 131
Co (under way)
- Organized a national (2007) and an international (2008), Ankara-Turkey
Tc comparison - 2008 scheduled;
- Participated at IAEA-TRS 454/2006,Quality Assurance for Radioactivity
Measurement in Nuclear medicine and other documents’ elaboration.
- CRP F42.006 „Updated Decay Data Library for Actinides” Contract
ROM /13341/2005-2008: „Improved decay data for important actinides”,
with details to be presented by Dr. Aurelian Luca
• The Radionuclide Metrology Laboratory
developed methods and equipment for absolute
• RML assured the whole traceability chain by
offering radioactivity standards and metrology
services to Romanian users.
• RML has a long tradition of participation in
• RML validated its standards by participating
in international programs of comparisons