IAEA-443 , Irish Sea water

Inorganic , Sea Water

In collaboration with IAEA-MEL, the Federal Maritime and Hydrographic Agency (BSH), Hamburg, Germany, collected about 3600 litres of surface water from the Irish Sea on-board Research Vessel Valdivia on September 7, 1993. Sampling was performed while cruising between two shallow (ca. 20 m water depth) stations located at 54°24,89' N - 3°33,62' W and 54°23,2'N - 3°33,45'W. Water was sampled from 5 m water depth, stored in 600 L containers and acidified to pH<1 immediately without prior filtration. A part of the sample was forwarded to IAEA-MEL and was used for the IAEA-381 interlaboratory comparison on anthropogenic and natural radionuclides. The results obtained from 28 laboratories were reported and the IAEA-381 certified reference material was issued.

In 2005, 1100 L of this sample, stored at the then Risø National Laboratory, Denmark, were provided to IAEA-MEL. The sample was then transferred into a container of 1500 L and mixed for 4 hours using two pumps, aliquoted into 5 L cubitainers and coded as IAEA-443. All units were sterilized according to ISO standards at 25 kGy in an irradiation facility.

This certified reference material is intended to be used for quality assurance purposes in the determination of radionuclides in sea water samples, including development and validation of analytical procedures, preparation and testing of reference methods, quality control, and training of analysts. This material is not to be used as a calibrator.

Certified values for massic activities 

Reference date for decay correction: 1 January, 2007

Radionuclide Certified value [Bq kg-1] Expanded uncertainty  [Bq kg-1]*
3H 37.2 0.5
40K 11.4 0.4
90Sr 0.110 0.005
137Cs 0.36 0.01
234U 0.044 0.002
235U 0.00185 0.00010
238U 0.039 0.002
238Pu 0.0031 0.0001
239+240Pu 0.0147 0.0002
241Am** 0.0197 0.0010

*Estimated expanded uncertainty with a coverage factor k=2, corresponding to a level of confidence of approximately 95%, as defined in the Evaluation of measurement data - Guide to the expression of uncertainty in measurement JCGM100:2008.
**The values should be corrected for in-growth from 241Pu.

Information values for massic activities 

Reference date for decay correction: 1 January, 2007

Radionuclide Information value [mBq kg-1] Combined expanded uncertainty [mBq kg-1]
230Th 0.5 0.1
232Th 0.19 0.03
239Pu 8.2 0.8
240Pu 7.0 0.6
241Pu 161 19


The assigned values were established on the basis of results reported  to the IAEA Environment Laboratories in Monaco by  laboratories which had participated in an interlaboratory comparison (ILC). The details concerning the criteria for qualification as certified or information value may be found in the report IAEA/AQ/10 (attached). 


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