ANSI HPS N13.59-2008 Characterization in Support of Decommissioning Using the Data Quality Objectives Process.pdf

1、 ANSI/HPS N13.59-2008 American National Standard Characterization in Support of Decommissioning Using the Data Quality Objectives Process Approved: July 3, 2008 American National Standards Institute, Inc. ANSI/HPS N13.59-2008 ii Published by Health Physics Society 1313 Dolley Madison Blvd. Suite 402

2、 McLean, VA 22101 Copyright 2008 by the Health Physics Society. All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without prior written permission of the publisher. Printed in the United States of America ANSI/HPS N13.54-2

3、008 iii This standard was consensus-balloted and approved by the ANSI-accredited HPS N13 Committee on March 14, 2008. At the time of balloting, the HPS N13 Committee had the following membership: Chairperson Tracy Ikenberry American College of Occupational and Environmental Medicine Bryce Breitenste

4、in American Industrial Hygiene Assoc. Irene Patrek American Iron and Steel Institute Anthony LaMastra American Mining Congress Scott C. Munson American Nuclear Insurers Bob Oliveira American Nuclear Society Nolan E. Hertel Conference of Radiation Control Program Directors Shawn Seeley Council on Ion

5、izing Radiation Msmts the goal is to have only those data necessary to select between alternative paths of future action. Decisions lay out those actions and the action levels (e.g., release criteria) for selection among alternative actions. This focuses the characterization, provides the quality cr

6、iteria for the data collection, and defines when characterization may be stopped. Laying out the decisions and ANSI/HPS N13.59-2008 2 specifying the action levels are done during planning, before any data are collected. 1.2 Scope This standard provides guidance for performing characterizations of la

7、nd areas and structures in support of decommissioning. In this context, land areas generally refers to environmental media such as soils, surface and ground water, and vegetation; structures typically refers to building construction materials. It is expected that when the ultimate objective of decom

8、missioning is site release, character-ization and final status survey design should be coordinated. Therefore, users of the MARSSIM or other final status survey protocols can use this standard for its technical approach to designing a characterization survey for a specific objective. The scope of th

9、is standard is geared toward radiological characterization. However, if non-radiological contaminants (e.g., asbestos, poly-chlorinated biphenyls (PCBs), lead, mercury, arsenic) are potentially present, it is beneficial to integrate radiological and non-radiological characterization activities. A us

10、eful reference for non-radiological characterization activities is ASTM E 1527-05. It is outside the scope of this standard to discuss all of the instruments, tools, and procedures currently available to support characterization activities. This standard does not apply to the release of materials an

11、d equipment. Similarly, it is outside the scope to address emerging characterization technologies. Rather, this standard endorses any and all instruments, tools, and procedures that effectively achieve the particular characterization objective. In this regard, the standard serves to focus the user o

12、n preparing a characterization survey plan based on the DQO process, drawing on specific instruments, tools, and procedures as needed. 2.0 Definitions The definitions and terms contained in this standard, or in other American National Standards referred to in this document, are not intended to embra

13、ce all legitimate meanings of the terms. They are applicable only to the subject treated in this standard. 2.1 Specific Word Usage The word shall is used to denote a requirement, the word should is used to denote a recommendation, and the word may is used to denote permission, neither a requirement

14、nor a recommendation. To conform to this standard, all survey activities and documentation shall be performed in accordance with its requirements, but not necessarily with its recommendations. 2.2 Specific Terms As Low As Reasonably Achievable (ALARA): An approach to radiological safety to manage an

15、d control exposures to levels that are as low as reasonable, considering social, technical, and economic factors. Background radiation: Radiation from naturally occurring radioactive materials that have not been technologically enhanced (i.e., not increased by or as a result of past or present human

16、 practices, e.g., oil and gas production pipe scale and phosphate industry wastes), cosmic and cosmogenic sources, and global fallout. Background reference area: A geographical soil area or structure surface area (i.e., building construction material) from which background radiation levels and radio

17、nuclide concentrations can be obtained and used for comparison to the radiation and radioactivity measurements per-formed in areas being surveyed. The distribution and concentration of radiation levels and radionuclide concentrations, as well as physio-chemical properties, in the background referenc

18、e area should be similar to those in the surveyed area (site) had the surveyed site never been contaminated. Calibration source: Radioactive material that has been characterized by, and is traceable to, a recognized standards or testing laboratory, such as the National Institute of Standards and Tec

19、hnology (NIST), for its radiological properties (e.g., particle emission rate). The calibration source is used for calibration of survey instruments and measurement systems. Check source: A radioactive source, not necessarily calibrated, that is used to confirm the continuing satisfactory operation

20、of a survey or measurement instrument. ANSI/HPS N13.59-2008 3 Data Quality Objectives (DQO) process: A planning tool that promotes the effective use of resources and increases the likelihood of efficiently collecting appropriate and useful data. DQOs are qualitative and quantitative state-ments deri

21、ved from the outputs of the DQO process that 1) clarify the objective, 2) define the most appropriate types of data to collect, 3) determine the spatial boundaries and practical constraints on collecting the data, and 4) specify tolerable limits on decision errors that will be used as the basis for

22、establishing the quantity and quality of data needed to support the decision. DQOs ensure that the type, quantity, and quality of the survey data used in decision making are appropriate for its intended use, at the same time promoting efficient use of resources by eliminating unnecessary, dupli-cati

23、ve, or overly precise survey data. DCGL: Acronym for derived concentration guideline level, a radionuclide-specific surface or volume residual radioactivity level that equates to the decommissioning release criterion and is derived through various exposure pathway scenarios. Energy dependence: A cha

24、nge in instrument response with respect to varying radiation energy. The efficiency of many survey and measurement instruments varies as a function of photon or particle energies. Graded approach: The process of ensuring that the level of detail or magnitude of resources applied to an item or work i

25、s commensurate with the intended use of the results and the degree of confidence needed in the quality of the results. Guideline: Level of radioactivity or radiation presented in terms of ambient radiation, surface activity, and radionuclide concentration in soil that represents the decommissioning

26、release criterion. Guideline unit: Unit of measure for measurement and sampling data that is consistent with the unit used for the applicable guideline, limit, or release criterion. Guideline units include Bq/cm2(or dpm/100 cm2) for surface activity and Bq/g (or pCi/g) for radionuclide concentration

27、s in soil. Hot spot: A general term that refers to an area of elevated contamination or radiation that 1) exceeds the average guideline level or 2) is markedly greater than the general contamination or radiation level. Instrument efficiency, i: Ratio of the instrument net count rate and the surface

28、emission rate of a source under specified geometric conditions. For a given instrument, the instrument efficiency depends on the radiation energy emitted by the source and the geometry between the detector and the source. Instrument efficiency is a 2 value (i.e., based on surface emission rate, not

29、activity) and shall only be used in surface activity determinations when multiplied by a surface efficiency to yield a 4 value of total efficiency. Minimum detectable concentration (MDC): The lowest activity concentration that can be detected with specific confidence for a given instrument and speci

30、fic measurement procedure. The MDC is usually specified as the lowest activity concentration that can be detected with 95% confidence (i.e., 95% of the time a given instrument and measurement procedure will detect activity at the MDC). Note that the term MDC applies to both activity present on a sur

31、face and to activity within a volume of a material. Quality assurance (QA): An integrated system of management activities involving planning, quality control, quality assessment, reporting, and quality improvement to ensure that radiological survey or measurement data meet defined standards of quali

32、ty with a stated level of confidence. Quality control (QC): The overall system of technical and procedural activities that measures the attributes and performance of a process, item, or service against defined standards to verify that they meet the stated requirements, such as those established by t

33、he regulator. Quality system: A structured and documented management system describing the policies, objectives, principles, organizational authority, responsibilities, accountability, and implemen-tation plan of an organization for ensuring quality in its work processes, products, and services. The

34、 quality system provides the framework for planning, implementing, documenting, and assessing work performed by the organization ANSI/HPS N13.59-2008 4 and for carrying out required quality assurance and quality control activities. Radiologically controlled area (RCA): An area that requires physical

35、 or administrative controls for purposes of protecting individuals from exposure to specific levels of radiation and radioactive materials. Radiological work permit: A work control document that identifies radiological conditions, establishes guidelines for workers protective clothing and dosimetry

36、and monitoring require-ments, and contains specific approvals for radiological work activities. Removable surface contamination: Radio-active material that can be removed from surfaces by nondestructive means, including casual contact, wiping, or washing. It does not include radioactive material tha

37、t is fixed and requires physical abrasion of the surface by scabbling or other physical means to remove the radioactive material. Surface efficiency, s: Ratio between the number of particles of a given type emerging from a given surface per unit time (surface emission rate) and the number of particl

38、es of the same type released within the source per unit time. The surface efficiency is nominally 0.5 but may be increased by back-scattered radiation and reduced by self-absorption. Surface emission rate: The number of particles of a given type (i.e., alpha, beta, or gamma) emerging from a given fa

39、ce of a source (or surface) per unit time. Total surface contamination: Radioactive material present on a surface that includes both removable and non-removable components. 3.0 Data Quality Objectives for Characterization 3.1 DQO Process The U. S. Environmental Protection Agency (EPA) has developed

40、a systematic planning process for data collection. This process focuses on the decision that would be supported by the dataso that only those data required for previously identified decisions would be collected, ensuring that the right quality and quantity of data are collected to make a specific de

41、cision. This systematic planning process is called the Data Quality Objectives (DQO) process. The DQO process, and the EPA orders and federal regulations that mandate a Quality System, are described in EPAs guidance document Guidance for the Data Quality Objectives Process (EPA 2000a). The document

42、addresses all environmental data operations, from initial characterization to final cleanup and release. The application of the DQO process ranges from a formal quantitative approach to an informal qualitative approach. Either way, it provides a good method for formally determining character-ization

43、 objectives, analyzing data requirements, presenting and discussing these requirements with decision makers and/or other stakeholders, and documenting the final decision criteria. This standard supports a flexible approach to the application of the DQO process. The seven-step DQO process is describe

44、d as follows (EPA 2000a). Step 1: State the Problem. In this step, the planning team is assembled and they develop a concise description of the problem. For instance, the team may develop a site conceptual model of the environmental hazard or issue to be investigated. Step 2: State the Decision(s) t

45、hat need to be made. The goal of this step is to define the questions that the study will attempt to resolve. For example, study questions might be “Are contaminants present in soil and sediment at the site that exceed appropriate release criteria?” and “What is the volume of soil that requires disp

46、osal as low-level waste?” Decision statements are then developed, and multiple decisions are organized into a decision logic diagram where each branch terminates in an action statement or set of actions that must be undertaken to resolve the problem. Step 3: State the Inputs to the Decision(s). The

47、purpose of this step is to identify the information inputs that are required to address each decision statement. In this step, sources of information in addition to the data that will be collected are identified. Often during this step, ANSI/HPS N13.59-2008 5 the type of data originally planned for

48、collection is shown not to be the type of data that will resolve the decisions in the decision logic from Step 2. During this step, the Action Level (i.e., the cut-off value for taking one action versus another, e.g., the release criteria) is identified. Often, the Action Level is a result of negoti

49、ation, a consensus among technical experts and regulators, and requires outside information. Step 4: State the Boundaries for the Decision(s). In this step, spatial, temporal, and practical boundaries to the problem are set. This helps narrow the problem and better define exactly what data are required. What is the size of the area to be surveyed? What grid sizes should be used for the survey? In statistical terms, the target population is defined, along with any subpopulations about which separate decisions must be made. Step 5: State the Decision Rule(s). This i