Code of Massachusetts Regulations › 310 CMR - DEPARTMENT OF ENVIRONMENTAL PROTECTION › Title 310 CMR 43.00 - Site Selection Criteria For Low-level Radioactive Waste Management Facilities › Section 43.60 - Guidelines and Procedures for Use in Preparation of the Candidate Site Identification Report

Current through Register 1525, July 5, 2024
(1)
Objective
. The principal objective of the Candidate
			 Site Identification Report is to identify at least two, but not more than five,
			 candidate sites that have a high likelihood of satisfying the requirements of
			 310 CMR
			 43.41(1). In addition, the
			 report is intended to present the results of a preliminary characterization of
			 the meteorology, surface and ground water, geology, tectonics, geomechanics,
			 air quality, ecology, land use, cultural resources and social and economic
			 characteristics of each such candidate site; a description of the procedure
			 used to identify the candidate sites based on such preliminary
			 characterization; and draft plans for detailed site characterization of each
			 candidate site. Installation of ground water wells is not required for sites
			 which are not selected as candidate sites. The purpose of 310 CMR 43.60 is to
			 provide guidance on how, at a minimum, the requirements for technically
			 superior sites should be interpreted and applied in the preparation of this
			 report.
(2)
Data
			 Collection and Evaluation Protocols.
(a) The Candidate Site Identification report
			 should be prepared on the basis of the types of data sources described at
			 310 CMR
			 43.40 and
			 43.50,
			 additional published and unpublished data and maps and additional field data
			 obtained and technical analysis carried out during this or previous phases of
			 the siting process.
(b) All
			 exclusion, conditional consideration and, in the Board's discretion, preference
			 criteria should be applied and evaluated in the preparation of the Candidate
			 Site Identification Report.
(c) The
			 Board may continue to use the GIS for data analysis and comparative evaluations
			 of siting factors. Map scales should be employed, if reasonably available,
			 which most accurately depict the characteristic being evaluated. Mapping
			 accuracy should be commensurate with the map scales employed and the accuracy
			 of the data sets.
(d) Computer
			 modeling may be used in the site evaluation process for those factors for which
			 computer models are determined to be reliable and valid in prediction,
			 including, but not limited to, generally accepted performance assessment,
			 hydrogeologic and hydraulic models. It is not required that the computer code
			 be specifically developed for low-level radioactive waste management siting
			 provided the code is applicable to the site/facility and the parameter being
			 investigated. Where a code is not generally accepted a determination of
			 reliability and validity should include, but not be limited to the following
			 factors:
1. The model should have supporting
			 documentation that establishes its ability to represent the factors under
			 investigation and any history of its previous applications;
2. The set of equations representing the
			 factor under investigation must be theoretically proven and must be well
			 documented;
3. The numerical
			 solutions must be based on sound mathematical principles and supported by
			 verification and checking techniques;
4. The model must be calibrated against site
			 specific field data developed in accordance with
			 310 CMR 43.00; and
5. A sensitivity analysis should be conducted
			 to measure the model's response to changes in the values assigned to major
			 parameters, specified error tolerances and numerically assigned space and time
			 discretizations.
(e)
			 Conceptual model uncertainty should be addressed by identifying a broad range
			 of conceptual models, and using each in performance assessments. Revisions of
			 these models should be made by accounting for progressive data collected that
			 can be used to eliminate some models from consideration. Uncertainties about
			 the future of the site should be addressed by projecting alternative future
			 site conditions. Parameter uncertainty may be addressed by using Monte Carlo
			 analysis in combination with other techniques (such as Latin Hypercube
			 Sampling) to reduce the computation effort.
(f) Despite the efforts to validate models,
			 substantial uncertainties are likely to be encountered in making predictions.
			 Sole reliance on these numerical predictions to determine compliance may not be
			 appropriate; the Board may chose to supplement such predictions with
			 qualitative judgments as well.
(g)
			 Any ground water wells that are installed to collect data and evaluate the
			 extent to which the site meets the criteria for a superior site should be
			 installed and maintained in accordance with Department guidance document,
			 standard Reference for Monitoring Wells, WSC-31-91.
(h) In the absence of specific Department
			 policy/guidance documents, the analysis of hydraulic factors necessary to
			 calculate saturated and unsaturated groundwater flow paths including, without
			 limitation, horizontal gradient, hydraulic conductivity, transmissivity,
			 hydraulic head, porosity, geometry, boundary conditions and the time of travel
			 of the flow shall be conducted in accordance with generally accepted standards,
			 principles and protocols, including, without limitation, a pump test performed
			 in accordance with generally accepted methods, if appropriate. Where an
			 evaluation of these parameters is dependent upon measurement of soil or water
			 samples the measurement may be done by direct measurement in situ or by the
			 testing of laboratory samples. The use of both methods is highly desirable, but
			 more extensive investigations may be deferred to the Detailed Site
			 Characterization stage.
(i) The
			 site characterization activities should be consistent with the guidance set
			 forth at
			 310
			 CMR 43.42(1)  to the extent
			 that the detail set forth in said guidance is consistent with and applicable to
			 the scope of a site investigation necessary to conduct a valid preliminary site
			 characterization. The Board should indicate in its report where further site
			 characterizations are to be deferred to the Detailed Site Characterization
			 stage. In addition to these guidelines the further guidelines of
			 310
			 CMR 43.61 and
			 43.62
			 should be applied.
(j) Where the
			 Board determines that adequate data exists and/or reasonable assumptions can be
			 made on site characteristics, waste characterization and probable facility
			 design, a preliminary performance assessment on likely sites may be conducted.
			 The purpose of the assessments is to assist in the evaluation of how the site
			 will perform by itself and in conjunction with suitable technologies to meet
			 DPH performance objectives. The preliminary performance assessments should be
			 used to estimate factors including, but not limited to:
1. The potential release of radioactivity
			 from waste packages into the facility;
2. The potential release of radioactivity
			 through the engineered barriers into the ambient or geologic
			 environment;
3. The movement of
			 radioactive materials through the environment to humans by ingestion or direct
			 contact;
4. The resulting exposure
			 to humans in comparison to DPH performance objectives and among the
			 sites.
(k) Performance
			 assessments need not provide complete assurance that DPH performance objectives
			 will be met. Because of the long time periods which may be involved and the
			 nature of the events and processes of interest, there will inevitably be
			 substantial uncertainties in projecting site and facility performance. What is
			 required is a reasonable expectation based on reasonably conservative
			 assumptions in relation to the record before the Board that compliance with DPH
			 dose performance objectives is reasonably likely to be achieved.