skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Allowable residual-contamination levels for decommissioning facilities in the 100 areas of the Hanford Site

Technical Report ·
DOI:https://doi.org/10.2172/5722142· OSTI ID:5722142

This report contains the results of a study sponsored by UNC Nuclear Industries to determine Allowable Residual Contamination Levels (ARCL) for five generic categories of facilities in the 100 Areas of the Hanford Site. The purpose of this study is to provide ARCL data useful to UNC engineers in conducting safety and cost comparisons for decommissioning alternatives. The ARCL results are based on a scenario/exposure-pathway analysis and compliance with an annual dose limit for three specific modes of future use of the land and facilities. These modes of use are restricted, controlled, and unrestricted. The information on ARCL values for restricted and controlled use provided by this report is intended to permit a full consideration of decommissioning alternatives. ARCL results are presented both for surface contamination remaining in facilities (in dpm/100 cm/sup 2/), and for unconfined surface and confined subsurface soil conditions (in pCi/g). Two confined soil conditions are considered: contamination at depths between 1 and 4 m, and contamination at depths greater than or equal to 5 m. A set of worksheets are presented in an appendix for modifying the ARCL values to accommodate changes in the radionuclide mixture or concentrations, to consider the impacts of radioactive decay, and to predict instrument responses. Finally, a comparison is made between the unrestricted release ARCL values for the 100 Area facilities and existing decommissioning and land disposal regulations. For surface contamination, the comparison shows good agreement. For soil contamination, the comparison shows good agreement if reasonable modification factors are applied to account for the differences in modeling soil contamination and licensed low-level waste.

Research Organization:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
DOE Contract Number:
AC06-76RL01830
OSTI ID:
5722142
Report Number(s):
PNL-4722; ON: DE83016642; TRN: 83-021293
Resource Relation:
Other Information: Portions are illegible in microfiche products. Original copy available until stock is exhausted
Country of Publication:
United States
Language:
English