Cooperation With South Korea

South Korean In Vivo Intercomparison Programme

The Head of the Human Monitoring Laboratory (HML) was invited (1995) by the Korean Atomic Energy Research Institute (KAERI) to assist in setting up a nationwide In Vivo intercomparison programme. KAERI was presented with details of the Canadian In Vivo intercomparison programme which has now been adopted in part by KAERI. The HML is continuing to assist KAERI with this work.

Calibration of KAERI's lung counter

KAERI has a lung counter that consists of four germanium detectors. They are 50 mm in diameter and 20 mm thick. The Head of the HML was invited (1996) by KAERI to help calibrate their lung counter. The HML also supplied the Asian torso phantom to KAERI. This phantom was designed and built in Japan, and better represents Korean workers. The American phantom is much larger than the average Korean.

In the course of calibrating KAERI's lung counter it was possible to directly compare the two phantoms and to compare two types of lung sets: sliced with planar sources, and whole with the activity homogeneously distributed throughout.

Preliminary results showed that the two phantoms were significantly different but not by more than about 20% - depending on the photon energy. A significant difference, also energy dependent was found between the two types of lungs sets. The results of this work have been published in the open literature. Kramer, G.H; Hauck, B.M; Lee, T-Y; Chang, S-Y. Comparison of sliced and whole lung sets for the LLNL and JAERI Torso Phantoms using Ge Detectors. Health Phys. 76(5): 547-552; 1999.

Measurement of the Lawrence Livermore National Laboratory (LLNL) Phantom.

The HML used its measuring device to characterize the thickness of the chest plate and the overlay plates of KAERI's LLNL phantom. It was found that the manufacturer's thickness values did not apply to the positions of KAERI's detectors on the phantom. This work will be published in the open literature and is similar to: Kramer, G.H., Hauck, BM Chest wall thickness measurements of the LLNL and JAERI torso phantoms for germanium counting. Health Physics 73(5): 831-837;1997.

Ultrasound Measurements of KAERI Staff.

The HML used its ultrasound unit to measure the chest wall thickness (CWT) of 120 male workers at KAERI. The results showed that the average CWT of the worker population was significantly smaller than the corresponding North American values.

Measurements were made at 14 locations above the left and 14 locations above the right lung in the regions where KAERI's lung detectors are placed. Measurement points were placed on each subjects chest,using a black marker pen, so that the measurements were precise. A 5 MHz linear array ultrasound probe was used for all the measurements.

The image below shows a typical ultrasound image recorded on the imager. In-built calipers were used to measure the CWT from the chest surface to the lung boundary. The chest wall is at the top of the screen. The elliptical dark circles in the top third of the picture are the ribs. The bright white horizontal line under the ribs is the lung boundary. The two dark vertical columns are shadows cast by the ribs as ultrasound cannot easily penetrate bone.

The data collected was age (yr), height (m), weight (kg),and CWT in centimeters (cm). The averages were 40.7 yr, 1.71m 69.3 kg, and 2.70 cm, respectively. The maximum values were 59.0 yr, 1.82 m, 98.0 kg, and 4.1 cm, respectively. The minimum values were 24.0 yr, 1.59 m, 54.0 kg, and 1.9 cm, respectively.

Memorandum of Understanding (MOU) between Health Canada and the Korean Atomic Energy Research Institute

A Memorandum of Understanding was signed March 15, 1999, between Health Canada and the KAERI. Both parties have agreed to the MOU for the following purposes:

• Formally establish scientific cooperation and inter-institutional relationships.
• Exchange data and information.
• Collaborate on research and development in the field of health physics.
• Collaborate in development of improved techniques and technology for assessing internal radioactivity burdens and resulting doses..
• Generally broaden the scientific experience of both parties.