Improvements on the Factored Estimate

Miller divides the plant into four areas Battery Limits, Storage and Handling, Utilities, and Services. The last three can often be estimated separately. They are a function of size of the facility and do not depend on the type of product being made. For instance, a steam plant, a warehouse, or an office building are the same 

Substential instrumentation, central control panels, petrochemicals MISCELLANEOUS CHEMICAL PLANTS Little instrumentation, solids 

INSTRUMENT- NOTE Total instrumentation costs does ATION not vary a great deal with size 

MISCELLANEOUS Includes site preparation, painting A other items not accounted for above 

NOTE When building specifications and dimensions are known a high speed building cost estimate is recommended especially if buildings are a significant item of cost. If a separate estimate is not possible, evaluate the buildings as follows before selecting the factors. 

---

The importance of choline as a nutritional factor has created a need for its estimation in biological materials and pharmaceutical preparations. Choline occurs bound in phospholipids (lecithins and sphingomyelin) and as acetylcholine, phosphorylcholine, and glycerylphosphorylcholine. Small amounts may occur in the free form. The estimation of choline and choline-containing compounds has been the subject of numerous reports in recent years, and has been discussed by Best and Lucas (13) in their excellent review in 1943. Since then, several new techniques and improvements on the older methods have been devised. 

Analyses and experimental results used to assess the consequences of a severe potential accident have resulted in substantially reduced estimates of severe accident consequences. Comparing estimates made by the U.S. Atomic Energy Agency (27) in 1977 with those reported by the U.S. NRC (18,28) in 1990 shows that improved knowledge and plant modifications have reduced the cote damage frequency by a factor of 3—15, depending on reactor type. Additionally, the fractions of radioactive species that would be released are lower by a factor of 10—100,000, depending on the radioactive species. 

For catastrophic demand-related pump failures, the variability is explained by the following factors listed in their order of importance system application, pump driver, operating mode, reactor type, pump type, and unidentified plant-specific influences. Quantitative failure rate adjustments are provided for the effects of these factors. In the case of catastrophic time-dependent pump failures, the failure rate variability is explained by three factors reactor type, pump driver, and unidentified plant-specific Influences. Point and confidence interval failure rate estimates are provided for each selected pump by considering the influential factors. Both types of estimates represent an improvement over the estimates computed exclusively from the data on each pump. The coded IPRDS data used in the analysis is provided in an appendix. A similar treatment applies to the valve data. 

On the other hand, the Hoar Committee s estimate for the UK did not include some significant factors, and some costs that were considered have increased in real terms since the estimates were made. Larger plants and structures are more common, and even when there is no increase in size more intensive use of equipment is demanded. As a result, the real cost of downtime or unavailability, and of dislocation to users of, for example, motorway viaducts while repairs are made, have increased appreciably. Moreover, maintenance and rectification are labour intensive activities, and hence particularly susceptible to the effects of inflation. The increases probably outweigh the savings mentioned, and the current cost of corrosion in the UK is probably around 4% of GNP. As future savings depend on the improvement being maintained despite pressures to reduce first costs, a sound economic approach to corrosion is no less important than it was in 1970. 

The accuracy of any expression for first order errors can be improved as much as desired (so long as the expression is differentiable) by including additional terms of its Taylor expansion. For example, the error magnification factor in the age equation for the 230Th/238u term, (p, can be improved to include the second derivative, so the estimate of the effect of a given error in cp on the age becomes ... 

The accuracy and reliability of an estimate can be improved by dividing the process into sub-units and using factors that depend on the function of the sub-units see Guthrie (1969). In Guthrie s detailed method of cost estimation the installation, piping and... 

In conclusion it can be stated that the basic assumptions of the re-entry model — a linear relationship between application rate and initial dislodge-able foliar residue and a first-order decay of the DFR — have been confirmed. The relationship between the transfer factor and re-entry time at various DFR levels should be explored further. Including information on foliage surface area or crop density may lead to a refinement of the model however, crop volume estimating methods should be improved before their influence on the exposure processes can be fully evaluated. 

Factors influencing the production and migration of radon in soils have been examined, and various sources of geographic data have been discussed. Two significant soil characteristics include air permeability and, less importantly, radium concentration. While there are, at present, few opportunities to compare the larger-scale data with on-site field measurements, those comparisons that have been made for both surface radium concentrations and air permeability of soils show a reasonable correspondence. Further comparisons between the aerial radiometric data and surface measurements are needed. Additional work and experience with SCS information on soils will improve the confidence in the permeability estimates, as will comparisons between the estimated permeabilities and actual air permeability measurements performed in the field. 

Initially, results reported for dry-combustion methods were found to be higher than wet-oxidation methods based on persulfate by factors of 2 or more. This discrepancy has steadily decreased as methodologies have improved. Contamination problems of dry methods have been reduced and the oxidation efficiency of the wet methods has been improved. While the differences between approaches have been discussed [94,95], there is still uncertainty whether the remaining difference between the two techniques is real - a result of incomplete oxidation, incorrect estimation of blanks, or a combination of both. 

---