REFERENCE SHEET REFERENCE SHEET REFERENCE SHEET REFERENCE SHEET
REFERENCE MATERIAL
IAEA IAEA IAEA
IAEA----315 315 315 315
RADIONUCLIDES IN MARINE SEDIMENT
Date of issue: January 2000⊕⊕⊕⊕
Recommended Values (Based on dry weight) Reference Date for decay correction: 1st January 1993
Information Values (Based on dry weight)
* Number of accepted laboratory means which were used to calculate the recommended or information values and corresponding confidence intervals about the median values.
§ 210Pb and 210Po are considered to be at equilibrium
⊕⊕⊕
⊕ Revision of the reference sheet dated March 1996
Radionuclide Recommended Value
Bq/kg 95% Confidence Interval
Bq/kg N*
40K 297 288 – 303 111
210Pb§ 30.1 26.0 – 33.7 33
226Ra 13.8 13.0 – 14.6 90
228Ra 26.7 25.3 – 28.0 51
228Th 27 24.0 – 28.9 22
232Th 25.6 24.5 – 27.5 36
234U 17.8 16.6 – 20.0 11
238U 17.6 16.1 – 18.5 31
Page 1 of 3 Radionuclide Information Value Bq/kg 95% Confidence Interval Bq/kg N* 230Th 16.9 15.1 – 20.9 8
235U 0.84 0.65 – 1.20 9
The values listed above were established on the basis of statistically valid results submitted by laboratories which had participated in an international intercomparison exercise organized in 1993. The details concerning the criteria for qualification as a recommended value can be found in the report (IAEA/AL/065; IAEA/MEL/61) "Report on the Intercomparison Run IAEA-315: Radionuclides in Marine Sediment" [1]. This report is available free of charge upon request.
Intended Use
This sample is intended to be used as a reference material for the measurement of radionuclides in marine sediments. It can also be used as a quality control material for the assessment of a laboratory's analytical work, for the validation of analytical methods and for quality assurance within a laboratory.
Origin and preparation of the material
The sediment material was obtained from the Health Physics Division of the Bhabha Research Centre, Bombay, India in 1991 near the Tarapur Atomic Power Station. This material is influenced by discharges from the Tarapur Atomic Power Station. The sediment is composed of clay minerals, mainly illite-montmorillonite with minor amounts of quartz, calcite, dolomite and feldspar. The material was freeze-dried then ground in pestle and mortar to pass a 250 µm sieve and the fraction below this size was homogenised in a rotating drum for four 8 hour periods. The material was dispensed in 100 g units.
Homogeneity
The homogeneity of the bottled material was assessed using marker radionuclides (40K, 60Co,
137Cs, 210Pb, 239+240Pu and 241Am) in 25 bottles taken at random.
Note: Evidence has been presented to suggest that this material may be contaminated with “hot particles” resulting from discharges from the Tarapur Atomic Power Station. The frequency of the occurrence of these “hot particles” is unknown and consequently, it is possible that significantly elevated activities may be observed for anthropogenic radionuclides in some sub-samples. For this reason activities of the anthropogenic radionuclides have been excluded from the certification of IAEA-315. However, data received for these radionuclides are presented in the report IAEA/AL/065.
Dry weight determination
All recommended values are expressed on a dry weight basis. Therefore, the dry weight must be determined at the time of analysis, using separate sub-samples of at least 500 mg dried to constant weight in a drying oven set to 105 °C. Subsequent weighings should differ by less than 5 mg.
Instructions for use
The recommended minimum intake mass for analysis of radionuclides is 50 and 10 g for gamma and alpha,beta-emitters respectively.
Analysts are reminded to take appropriate precautions in order to avoid contamination of the material during handling. No special precautions are required for the storage of this material.
Legal disclaimer
The IAEA makes no warranties, expressed or implied, with respect to the data contained in this reference sheet and shall not be liable for any damage that may result from the use of such data.
Page 2 of 3
References
[1] Ballestra S., Gastaud J., Parsi P. and Vas D., Report on the Intercomparison Run IAEA-315: Radionuclides in Marine Sediment.
IAEA/AL/065 (IAEA/MEL/61), IAEA, Monaco 1996.
Issued by
Marine Environment Laboratory (MEL) International Atomic Energy Agency
B.P. No 800 MC-98012 Monaco
Supplied by
Analytical Quality Control Services (AQCS) Agency’s Laboratories, Seibersdorf International Atomic Energy Agency
P.O. Box 100 A-1400 Vienna, Austria
Prepared by
S. Ballestra, J. Gastaud, P. Parsi and D. Vas
Page 3 of 3
