Installation of a pilot experimental trench at the Little Forest legacy site

During 2017, a pilot experimental trench was constructed at the Little Forest Legacy Site (LFLS). The objective of installing this trench was to facilitate experimental field-work aimed at further characterising the site, in particular the hydrology of the excavated trenches and of the near-surface layers in which the trenches are located. The test trench is of similar depth to the waste disposal trenches at the legacy site (3 metres) and extends 6 m in length. However, unlike the disposal trenches, the experimental trench contains no waste materials of any kind. Instead, the trench contains a number of sampling points and other instrumentation, and is back filled with river gravel to provide a uniform composition and maintain structural stability. It is intended that the pilot trench will be followed by other trenches with specific experimental objectives. The purposes of this report are to discuss the background, rationale for, and implementation of the facility; to provide a detailed description of the pilot trench; and to compile information and photographs documenting the excavation process. Although some preliminary hydrological data and comparisons with the legacy trenches are presented, the scientific data will be fully discussed and interpreted in future scientific reports.
Radioactive wastes, Sampling, Ground water, Shaft excavations, Radioisotopes, Research programs
Payne, T. E., Kinsela, A. S., Bligh, M., Rowling, B., Hughes, C. E., Hankin, S., Anderson, D., Cendón, D., Wilsher, K. & Comarmond, M. J. (2018). Installation of a pilot experimental trench at the little forest legacy site : July 2018: (ANSTO/E786). Lucas Heights: Australian Nuclear Science and Technology Organisation.