Benchmarking of the CAP-88 and GENII computer codes using 1990 and 1991 monitored atmospheric releases from the Idaho National Engineering Laboratory.

The CAP-88 environmental radiological assessment computer code was benchmark tested to establish confidence in its results. The results from CAP-88 were compared to the results from the GENII computer code, which has undergone rigorous testing. The codes were benchmarked using 1990 and 1991 monitored atmospheric releases from Idaho National Engineering Laboratory facilities and the results (the effective dose equivalent to the maximally exposed offsite individual) were quantitatively compared using a metric based on the uncertainty in the Gaussian plume model and terrestrial transport models. The results of the benchmark tests were within the 95% acceptance region specified in the test protocol. CAP-88 was found to overpredict effective dose equivalent relative to GENII for elevated releases, largely because CAP-88 calculates a larger atmospheric dispersion factor (chi/Q) than does GENII using the same meteorological data. However, CAP-88 consistently underpredicted effective dose equivalent relative to GENII for ground-level releases. This was because CAP-88 accounts for the processes of plume depletion by dry and wet deposition while GENII does not account for these processes. The effect of depletion was tested and found to be most important for a ground-level release of a highly depositing species such as radioiodine which implies that acceptable benchmark results would be difficult to obtain for a highly dopositing species.

Anterior cruciate ligament reconstruction by over-the-top repair combined with popliteus tendon plasty.

We used the MacIntosh over-the-top repair combined with a popliteal tendon plasty in 273 athletically active patients with chronic incapacitating functional instability due to anterior cruciate ligament rupture; 244 were reviewed at three to nine years after operation. We describe the technique and its results, with functional evaluation by the Tegner and Lysholm system. Excellent or good results were obtained in 71%; most of the 29% fair or poor results were due to extensive meniscal and degenerative changes. In a group of 11 patients with excellent results arthroscopic and histological findings were encouraging, showing good incorporation of the graft.

Use of a simulation model in occupational dose assessment at a high-level radioactive waste repository.

Occupational radiation dose assessment at a nuclear facility can benefit from a systems approach that recognizes the complex dynamics of the facility. A simulation model can be a useful tool for accomplishing this goal. This technique can quantify the uncertainty in estimates of occupational dose equivalent and illustrate the effects of system interactions. A simulation model of operations at a high-level radioactive waste repository together with a radiological dose assessment model were used to illustrate this technique. Annual individual and collective occupational dose equivalents were estimated in the truck cask receiving and handling stations at a repository. The uncertainty of these estimates is shown through the use of complementary cumulative distribution functions. The effects of changing parameters in cask handling operations are examined.