Remedial actions: evaluation

With regard to the availability of design information for the submarine and icebreaker SGIs, a great deal is still unknown about the support structures for the reactor cores, thermal shields, and RPVs. While sufficient information is knowm about the disposal of the SNF fh)m the icebreaker as to make this less of a concern, the lack of this information is most significant for criticality studies and remedial action evaluation of the submarine RPVs that contained SNF. 

Information is distributed through periodic summaries of accident statistics, status reports on safety measures, special reports, etc. There are different uses of this information such as input to decisions on remedial actions, evaluation of the effects of these actions, and monitoring of SHE performance. The database also provides mandatory reports on accidents to insurance companies and the authorities. 

The apparent cause(s) of the complaint(s) is (are) identified Remedial action and follow-up evaluation will confirm whether the hypothesis is correct. 

The components of each factor can be evaluated at two levels of detail. An example of these levels for the factor "Procedures and Job Aids" is provided in Figure 2.12. If the question indicates that the first level (e.g., content and reliability) is deemed to be inadequate then more questions are available at the next level of detail (the topic level) to provide additional information on the nature of the problem. For each topic, further questions are provided at a greater level of detail. These detailed questions (diagnostics) are intended to pinpoint the precise nature of a deficiency and also to provide insights for remedial action. 

A number of site-specific factors must first be evaluated. Including (1) the chemical characteristics and amount of hazardous waste, (2) the potential for release to the environment, (3) the sensitivity of the particular environment to the hazardous waste, (4) the proximity of the hazardous waste to humans, and (5) Its potential effect on human health. Then the environmental engineer must decide If a field Investigation of the site Is necessary, whether a feasibility study for remedial action Is required, what remedial action Is required to mitigate. If not eliminate, the contamination, and finally, what monitoring plan will enable the efficacy of the remedial action to be evaluated. 

The components of FS comprise developing, screening, and evaluating alternative remedial actions. 

Evaluating the need for a treatability study. The requirement and schedule for treatability studies so as to better evaluate potential remedial alternatives are identified. If remedial actions involving treatment have been identified for a site, then the need for treatability studies should be evaluated as early as possible in the RI/FS process. This is because many treatability studies may take several months or longer to complete. 

The sources of contamination are usually those hazardous materials that are contained in drums, tanks, surface impoundments, waste piles, and landfills, as well as heavily contaminated media (such as soil) affected by the original leaking or spilling source. The purpose of defining sources of contamination is to help to identify the source location, potential releases, and engineering characteristics that are important in the evaluation of remedial actions, as well as waste characteristics, such as the type and quantity of contaminants that may be contained in or released to the environment, and the physical or chemical characteristics of the hazardous wastes present in the source. 

Modeling of evaluative and real environments should be viewed as complementary. Evaluative models are particularly suitable for assessment of new chemicals, for comparing chemicals, and for obtaining general chemical behavior profiles. Real models are obviously best used for elucidating the actual or potential nature of contamination situations and remedial actions. The use of similar or identical calculation techniques in both is very desirable since success in the real case may lead to greater credibility in the evaluative case. 

A major objective in developing these risk estimation procedures was to provide a method capable of evaluating hundreds of properties in several communities within the DOE Uranium Mill Tailings Remedial Action Program in a timely manner. Therefore, we chose a calculation scheme that could be performed using commercially available database software (dBASE II, a trademark of Ashton-Tate, Culver City, CA), but that at the same time would be flexible enough that assessments for other contaminants could be readily incorporated. 

The QC manager, QA manager, and production manager will evaluate and approve the results in case of failure and determine the remedial actions. 

If it deems it necessary, the USEPA can require an expedited response action (ERA) at a site that would require an immediate engineering evaluation/ cost analysis (EE/CA). After a removal action is completed or determined unnecessary, the long-term remedial action must be undertaken. First, a remedial investigation/feasibility study (RI/FS) is performed to determine a proper course of action. This can involve ... 

Calibration procedures shall include specific directions and limits for accuracy and precision. When accuracy and precision limits are not met, there shah be provisions for remedial action to re-establish the limits and to evaluate whether there was any adverse effect on the device s quality. These activities shah be documented. 

The procedural controls to be followed if the system fails or breaks down should be defined, and specified. Any failures and remedial actions must be recorded and evaluated. 

One of the initial TRE procedures includes the collection and review of available data and facility specific information, as well as an evaluation of remedial actions to optimize facility operation. The key components of this preliminary assessment include an evaluation of ... 

Taking into account these difficulties and all discussions and evaluations of recent research results, many authors propose the weak salt solutions of calcium chloride, sodium nitrate and ammonium nitrate as extraction reagents to predict the risk/ toxicity associated to soil PTMs pollution or residing after remediation actions (Kabata-Pendias, 2004 Keller and Hammer, 2004 Ure and Davidson, 2002). 

A straight-line model is the most used, but also the most misused, model in analytical chemistry. The analytical chemist should check five basic assumptions during method validation before deciding whether to use a straight-line regression model for calibration purposes. These five assumptions are described in detail by MacTaggart and Farwell [6] and basically are linearity, error-free independent variable, random and homogeneous error, uncorrelated errors, and normal distribution of the error. The evaluation of these assumptions and the remedial actions are discussed hereafter. 

Acknowledgment that mixtures may cause risks that are not fully covered by single compound evaluations does not automatically imply that mixture assessments should be performed for all potential mixture exposures. This depends on the problem at hand, the specific exposure situation, and the available information. If a regulator must make a decision about the remediation of 1 contaminated soil plot, and it is already known that one of the mixture components exceeds the remediation threshold, and this fact results in a need for remedial action itself, then a mixture assessment is redundant. Mixture assessment for contaminated soils (and other compartments and exposure routes) is useful if the known individual components do not exceed their respective thresholds, but if it is suspected that the overall mixture may still cause unacceptable adverse effects, and in case risk managers have a limited budget for a large number of contaminated sites, that is, when they have to prioritize the most hazardous sites to be remediated first, while other sites should possibly be subject to simple risk reduction measures. The situation is different for mixture emissions. Here, potential mixture effects should always be addressed because the aim was and is to establish an emission level that is lower than a certain (acceptable) effect level. 

The following checkhst is based on work by the German APV for practitioners validating existing compnter systems that were not, or were only partially, developed in accordance with validation reqnirements. Some practitioners prefer to use the term retrospective evaluation to highlight that the exercise is founded on the principle of a comphance gap analysis and conseqnential remedial actions. It is important to realize that any retrospective vahdation takes more elTort than prospective validation and rarely achieves the same standard. 

As a necessary prerequisite for the correct operation of maintenance functions as well as for the GLP requirement of traceability it is important that any problems or inconsistencies detected during the daily operation of the system are recorded, and that any consequent remedial actions taken are docmnented. Changes to the computerised system may thus become necessary through maintenance-related events, but they may also be intentionally introduced through the perceived need for additional or changed application modules. All such changes have to be evaluated in terms of their influence on the validation status of the system. To deal with such situations, change... 

The Remedial Action Priority System (RAPS) and Multimedia Environmental Pollutant Assessment System (MEPAS) are different names for an objective exposure pathway evaluation system developed by Pacific Northwest Laboratory to rank chemical and radioactive releases according to their potential human health impacts. Constituent migration and impact are simulated using air, groundwater, overland, surface water, and exposure components based on standard assessment principles and techniques. A shell allows interactive description of the environmental problem to be evaluated, defines required data in the form of problem-specific worksheets, and allows data input. The assessment methodology uses an extensive constituent database as a consistent source of chemical, physical, and health-related parameters. 

Pacific Northwest Laboratory has developed health impact assessment systems, the Remedial Action Priority System (RAPS) and the Multimedia Environmental Pollutant Assessment System (MEPAS), for the U.S. Department of Energy (DOE) to evaluate the relative importance of environmental problems. RAPS, which was developed first, applies to releases from inactive waste sites. MEPAS, the most recent version of the system, allows consideration of releases from both active and inactive sites. MEPAS differs from RAPS mainly in terms of the types of emission options. Although MEPAS retains the documented framework of RAPS (1), several enhancements have been added to the transport and exposure components (2). 

The MEPAS shell has elements of a knowledge-based system. The source term, environmental. transport, and exposure assessment data entries build a database of information that can be used to define additional environmental problems. This feature, which was added to simplify evaluation of similar or related problems, will also be useful in the evaluation of remedial action alternatives for site cleanup using a baseline case. Also the knowledge base in the constituent database grows as MEPAS is applied to new constituents. 

DOD s prioritization methodology determines the sequence in which munition sites should be investigated and evaluated, not whether or what type of remedial action will be taken at any given site. For example, a site could have a high priority, but the remedy selected might be leave in place with long-term stewardship. The decision on whether... 

Testing and Evaluation of Permeable Materials for Removing Pollutants from Leachates at Remedial Action Sites... 

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