Abacc laboratories quality assurance
through secondary standards exchange program
Olga
Mafra Guidicini, 1 Jay
Thompson2 and Michael
Soriano2
1 ABACC Headquarters, Rio de Janeiro, Brazil; 2 New Brunswick
Laboratory, U. S. Department of Energy, Argonne, IL, USA.
In September 1999, the Brazilian-Argentine Agency for Accounting
and Control of Nuclear Materials (ABACC), with assistance
from the New Brunswick Laboratory (NBL) of the U.S. Department
of Energy, started a new cooperative activity with, among
other objectives, the production and characterization of
a traceable uranium secondary standard and the performance
of the Third Round Robin for ABACC’s laboratory network.
Brazil and Argentina have fabricated UO 2 pellets for use
as a secondary standard. Samples from the two batches were
sent to NBL for the determination of the reference values
for both uranium concentration (%U) and isotopic composition
for each batch.
ABACC and NBL then organized the Third ABACC Round Robin
for Brazilian and Argentine laboratories that are part of
the ABACC network. The laboratories comprising the network
can be used to analyze real samples collected during the
ABACC inspections.
The Brazilian and Argentine pellets were distributed to
all the laboratories together with the protocol to be followed
for the uranium concentration analysis, the forms for reporting
the measurement results, and natural UO 2 pellets (CETAMA
OU1) to be used as reference material. For the laboratories
with capability of measuring isotopics, NBL reference material
CRM 125-A was provided.
Several laboratories from each country provided results.
As soon as the measurement results were sent to the organizers,
they were statistically evaluated by NBL. During a meeting
held at ABACC headquarters with the participation of NBL
representatives, the ABACC technical support officer, and
representatives of all the participant laboratories, the
results were discussed and compared with the reference values.
All the laboratories had the occasion, in an open discussion,
to explain and show the difficulties and problems they faced
during the exercise. ABACC had the opportunity not only to
judge the quality of the measurements these laboratories
performed, but also to determine possible improvements in
their measurement processes.
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