Nuclear Regulatory Research
On this Page:
- Office of Nuclear Regulatory Research
- Program Management, Policy Development and Analysis Staff
- Division of Engineering
- Division of Systems Analysis
- Division of Risk Analysis
Office of Nuclear Regulatory Research
Director: Brian Sheron
Deputy Director: K. Steven West
Provides leadership; plans, recommends, manages and implements programs of nuclear regulatory research; and interfaces with all NRC offices and the Commission on research issues. Independently proposes improvements to the agency’s regulatory research programs and processes to enhance safety, efficiency, and/or effectiveness based on research results, and coordinates research activities with the program offices, as appropriate. Also coordinates the development of consensus and voluntary standards for agency use, and appoints RES staff to committees. Based on research results and experience gained, recommends regulatory actions to resolve ongoing and potential safety issues for nuclear power plants and other facilities regulated by the NRC, including those issues designated as generic issues (GIs). Assesses the effectiveness of selected NRC programs, including the agency’s regulations and regulatory guidance, with regard to risk reduction potential, burden reduction potential and the appropriate degree to which safety margins exist in the design and operation of licensed facilities. Develops and maintains computer codes and databases used in evaluating the response of systems, structures and components of nuclear reactors and nuclear materials facilities under normal and hypothetical accident conditions, of both current and future design. Conducts research to reduce uncertainties in areas of potentially high safety or security risk or significance. Develops the technical basis for risk-informed, performance-based regulations in all areas regulated by the NRC. Leads the agency’s initiative for cooperative research with the U.S. Department of Energy (DOE) and other Federal agencies, the domestic nuclear industry, U.S. universities, and international partners. Coordinates research activities outside the agency, and appoints RES staff to domestic and international committees and conferences. Maintains technical capability to develop information for resolution of nuclear safety and security issues, and provides technical support and consultation to the program offices in the related specialized disciplines. Provides independent analysis of operational data and assessment of operational experience through the review, analysis, and evaluation of the safety performance of facilities licensed by the NRC. Collects and analyzes operational data; assesses performance trends derived from these data; evaluates operating experience to provide insights and improve understanding of the risk-significance of events, “near-missses,” and trends; and produces and disseminates periodic performance indicator and accident sequence precursor (ASP) report. Provides program direction, coordination, and implementation for homeland security research. Also provides administrative and technical support for the Committee to Review Generic Requirements (CRGR). Coordinates domestic and international cooperative nuclear safety research activities, including the Code Applications and Maintenance Program (CAMP), the Cooperative Severe Accident Research Program (CSARP), and other programs with the Organization for Economic Cooperation and Development/Nuclear Energy Agency and the International Atomic Energy Agency.
Program Management, Policy Development and Analysis Staff
Director: Glenn Trent (Acting)
Deputy Director: (Vacant)
Provides leadership and manages short- and long-term strategic and programmatic planning, resource forecasting and allocation, and budgeting. Coordinates the development and oversight of the RES operating plan. Manages and coordinates the execution of financial resources for RES. Provides overall administrative and financial management and planning for RES technical assistance projects with private contractors, Federal agencies, and DOE National Laboratories. Provides overall program planning, management, and guidance for the development of objectives and requirements for contracted technical assistance programs. Provides independent review of non-technical RES policy papers and issues to ensure completeness, promptness, accuracy, and adherence to agency and office policy.
Manages, coordinates, and supports the acquisition of appropriate information technology and information management (IT/IM) infrastructure. Provides administrative and management support in the areas of human resource management, equal employment opportunity (EEO), facilities management, training, Freedom of Information Act (FOIA) coordination, and management of principal correspondence for RES. Directs and coordinates office communication plans and strategies, provides technical editing support, and leads and coordinates special projects (e.g., knowledge management). Also manages and coordinates responses to inquiries from the Commission, Advisory Committee on Reactor Safeguards (ACRS), Office of Management and Budget (OMB), and Congress, and responds to inquiries related to the RES budget and technical applicability of the agency’s research program, including resource tradeoffs within the technical and programmatic context. Assists in coordinating the RES operating plan with those of the NRC’s other major offices. Supports and coordinates with other NRC offices and DOE laboratories. Also supports and coordinates the annual Regulatory Information Conference (RIC), and assists in coordinating intra- and inter-agency special projects and international agreements.
Financial and Performance Management Branch
Chief: Lisa Bamford
Oversees and manages short- and long-term strategic and programmatic planning, resource forecasting and allocation, and budget formulation and execution. Coordinates the development and implementation of the RES Operating Plan, Performance Report and Internal Controls. Manages and coordinates the execution of financial resources for RES, including tracking and maintaining user need requests, FTE and spending analyses, and performance and financial reporting. Manages and coordinates responses to budget-related inquiries from the Commission, Office of Management and Budget, and Congress. Lead for implementing the internal control program within the office and ensures the proper implementation and reporting of fee billable contract costs. Also ensures the timely compilation and submittal of quarterly reports of office reimbursable expenditures.
Provides overall administrative and financial management and planning for RES technical assistance projects with private contractors, Federal agencies, and DOE National Laboratories. Provides overall program planning, management, and guidance for the development of objectives and requirements for contracted technical assistance programs. Manages the RES mid-year and annual Advance Procurement Plan. Oversees and tracks overall PMDA spending. Provides approving authority for bankcard purchases. Provides support to, and coordinates with other NRC offices on policies and procedures related to acquisition management. Provides analyses and recommendations to the RES front office on office commitments, obligations, and expenditures.
Human Capital and Communications Branch
Provides administrative and management support in the areas of human resource management, equal employment opportunity (EEO), labor-management partnership, facilities management, training, and management of principal correspondence for RES. Manages RES Nuclear Safety Professional Development Program, RES new employee on-boarding, Flexiplace and performance management programs. Manages and coordinates secretarial coaching and training programs. Provides support for the RES Roster, RES Seminars Program, Travel Card approval and e-Travel policies and procedures, the RES Occupant Emergency Plan and RES Office Instructions and the RES Suggestion Program. Directs and coordinates Office communication plans and strategies, and provides technical editing support. Maintains external communications with other support offices. Provides independent review of non-technical RES policy papers and issues to ensure completeness, promptness, accuracy, and adherence to agency and Office policy. Responsible for issuance of regular Office communications, such as the weekly "PMDA Notes" and PMDA announcements. Serves as contact for the annual FAIR Act, Agency-wide recognition, leadership development and awards programs and the Differing Professional Opinion program. Supports RES knowledge management program. Also coordinates and supports the annual Regulatory Information Conference (RIC).
Information Technology and Infrastructure Branch
Chief: Tom Kardaras
Oversees, manages, coordinates, and supports the overall RES information management (IT/IM) infrastructure and acquisition of appropriate information technology to support RES IT/IM needs. Provides RES web maintenance and oversees web content. Advises on IT security and provides routine, daily administrative IT support. Oversees administration of IT equipment and the IT bankcard. Responsible for new employee set-up, HRMS/TAC assignments. Manages and oversees the RES Global Calendar and the RES Freedom of Information Act (FOIA) and records management programs.
Division of Engineering
Director: Michael Case
Deputy Director: Brian Thomas
Plans, develops, and directs comprehensive safety research programs and standards development to support the NRC strategic goals in the design, construction, and operation of current and advanced nuclear power plants and other facilities regulated by the NRC. Coordinates research activities with the program offices, as appropriate, on areas that include material characteristics, aging, natural hazards, homeland security, and engineering aspects of these facilities. Resolves technical, security, and safety issues, including those designated as generic issues (GIs), related to engineering and material issues. Within scope of responsibility, assesses the NRC's regulations and regulatory guidance with regard to risk significance, burden reduction potential, and the engineering design margins associated with facility systems, structures and components. Manages the prioritization of technical activities and through contract or agreement arranges for necessary technical support or collaboration with DOE, other Federal agencies, commercial sources, international parties, and universities consistent with the Division's budget. Consistent with NRC policy, and to the extent overall Agency need exists, maintains liaison and provides technical input in assigned areas to other Federal agencies, American National Standards Institute, other professional societies, international agencies, and other organizations. Independently recommends improvements in NRC programs/processes to achieve outcomes of enhanced safety, efficiency or effectiveness. Has lead agency responsibility for coordinating NRC codes and standards activities as these relate to federal law and interaction writing organizations, including activities relating to the National Technology Transfer and Advancement Act of 1995 (Public Law [PL] 104-113) and OMB circular A119, "Federal Participation in the Development and Use of Voluntary Consensus Standards and in Conformity Assessment Activities." Supports the priority scheduling and revision or development of Regulatory Guides (RGs) and draft RGs (DGs) during review of agency infrastructure to support new reactor licensing activities. Maintains broad technical expertise in the relevant engineering technology areas and provides appropriate technical support to the program offices.
Component Integrity Branch
Chief: David Rudland
Develops methods, data, standards, and metallurgical modeling tools for identifying and evaluating degradation mechanisms that arise from irradiation on reactor pressure vessel steels; investigates the capabilities of fracture mechanics measurement and analysis technologies; develops methods, data, standards, and modeling tools to assess the mechanical performance of SSCs; develops the technical basis for revisions to ASME Section XI; provides and applies tools to quantitatively assess changes in structural reliability of nuclear plant systems, structures and components as a result of operating environment effects or aging of materials; evaluates the reliability of non-destructive examination methods for operating and new reactors; maintains the agency=s Best Practices ISI website; maintains expertise in Materials Engineering, Mechanical Engineering, Non-destructive Examination Methods and Metallurgy to support NRC's assessments of component integrity.
Corrosion and Metallurgy Branch
Chief: Mirela Gavrilas
Develops the data to characterize the causes and effects of corrosion and environmentally-assisted cracking on the structures and components of nuclear plant systems; conducts materials degradation studies of irradiated-assisted stress corrosion cracking, stress-corrosion cracking, materials fatigue, and general corrosion; assesses in-service inspection techniques to ensure steam generator tubes integrity; assesses the effect of chemical and corrosion issues on the mechanical performance of SSC's, maintains expertise in Metallurgy, Physical Chemistry, and Materials Science to support NRC needs for methods, data, standards, and tools associated with corrosion and cracking of nuclear power plant structures and components.
Regulatory Guidance and Generic Issues Branch
Chief: Thomas Boyce
Facilitates reviews and updates to agency regulatory guidance, particularly Regulatory Guides (RGs), through coordination with all organizations in NRC. Specifically responsible for the NRC's program for review, development, revision, and withdrawal of over 400 NRC RGs and draft RGs (DGs).
The RGDB staff works with other NRC staff to assist in formatting, technical editing, assembling packages for concurrence, issuing DGs for public comment, facilitating appropriate committee review(s), and issuing draft and final guides. Establishes the agency's standards for organization, tone, and required/standard content of guides; coordinates agency involvement in consensus codes and standards; represents NRC on OMB Circular A-119 requirements.
Manages the congressionally mandated Generic Issues Program for the agency. The program addresses issues that have significant generic implications related to safety or security which cannot be more effectively resolved by other regulatory programs or processes. The program uses Commission approved criteria to effectively place issues that have risk significance either within the program or with a regulatory office for resolution. The criteria assure that worthy issues enter the program and receive ample support and issues that are inadequately defined or have low risk do not divert agency resources. The program provides for participation on issues by affected offices and facilitates the development of agency consensus positions.
Instrumentation, Controls, and Electrical Engineering Branch
Chief: Russell Sydnor
Develops and applies methods, data, tools, standards, and guidance to assess the adequacy of digital I&C; develops and implements a broad research program in the area of digital instrumentation and control addressing digital system contributions to risk, software attributes that can affect safety or security, new reactor designs, and development of consensus standards; develops and applies methods, data, tools, standards, and guidance to assess the adequacy of electrical equipment; develops the technical bases to resolve electrical engineering issues such as equipment qualification, associated circuits, grid reliability; develops monitoring techniques for cable degradation; monitors operating experience; maintains expertise in Instrumentation and Control Engineering and Electrical Engineering to support the identification and resolution of I&C and electrical issues important to nuclear power plant safety.
Structural, Geotechnical and Seismic Engineering Branch
Develops and applies methods, data, standards, and modeling tools to assess the structural performance of SSCs; develops the technical bases and computational methods to resolve structural engineering issues associated with security assessments; collects and analyzes data related to seismic hazard and seismic performance of structures; develops and applies seismic design analysis methods and guidance for geotechnical and structural design elements; maintains expertise in Structural, Geotechnical, and Seismic Engineering, including Seismology and Geophysics.
Division of Systems Analysis
Director: Kathy Halvey Gibson
Deputy Director: Stuart Richards
Plans, develops and manages research programs to develop and maintain broad technical expertise, experimental data, numerical simulation analyses tools, and the knowledge bases needed to provide the NRC with the ability to make reliable and technically sound regulatory decisions. Coordinates research activities with the program offices, as appropriate. Works in partnership with universities, laboratories, and other national and international research centers involved in complementary areas. Maintains an infra-structure of criticality safety, thermal-hydraulic and severe accident phenomenology, accident source terms, accident sequence analysis and develops analytical capabilities for realistic analyses to be used in support of risk-informed regulatory decisions for a wide spectrum of conditions, including normal operation, accident, and severe accident conditions for current, new and advanced reactor designs. The developed computer codes and data are used to provide the technical infrastructure for reviewing and performing confirmatory analysis to support licensing decisions. Conducts research to quantify margins, reduce unnecessary burden, and reduce uncertainties for areas of potentially high risk or safety significance. Develops the methods, data, standards, and modeling tools to assess dose and health effects. Develops the methods, data, standards, and modeling tools to assess the magnitude and effect of released radioactive material to the environment outside nuclear facilities. Maintains broad technical expertise and provides consultation to NRC organizations in these specialized areas.
Reactor Systems Code Development Branch
Chief: Chris Hoxie
Plans, develops and manages research programs to develop and maintain computer codes, models and experimental data bases for evaluating coupled neutronic and thermal-hydraulic transient behavior of nuclear reactor and plant systems under normal, abnormal, and accident conditions for current and advanced reactors. Plans, develops and manages research programs to develop and maintain computer codes, experimental data bases and analytical capabilities for evaluating fuel behavior under normal, abnormal and severe accident conditions for current and advanced reactor designs. Works in partnership with universities, laboratories, and national and international research centers involved in complementary areas. Maintains experimental data, fuel, and coupled neutronic and thermal-hydraulic analytical tools and knowledge bases, and provides consultation to NRC organizations in these specialized areas to make reliable and technically sound regulatory decisions.
Reactor Systems Analysis Branch
Chief: Scott Elkins
Performs thermal-hydraulic and computational fluid dynamics analytical analyses to support NRC offices in making reliable and technically sound regulatory decisions and safety assessments for current and advanced reactors. Conducts thermal-hydraulic research to quantify margins, reduce unnecessary burden, and reduce uncertainties for areas of potentially high risk or safety significance. Works in partnership with universities, laboratories, and other national and international research centers involved in complementary areas. Plans, develops and manages analytical and experimental research programs on the performance of the primary coolant systems of nuclear plants, including thermal-hydraulic transient behavior and interaction with the balance of plant under normal, abnormal, and accident conditions. Lead for small modular reactor (SMR) and aqueous homogeneous reactor (AHR) research.
Radiation Protection Branch
Plans, develops, performs, and manages research programs supporting risk-informed regulatory decision-making in radiation protection at nuclear power plants, materials facilities and users, and fuel cycle facilities. Serves as an agency-wide resource by providing technical support in all aspects of radiation protection to program offices as well as to NRC's domestic and international regulatory and scientific counterparts. Develops and maintains computer codes for assessment of radiation doses to workers and members of the public; analyzes and reports worker exposure to Congress and other stakeholders; and executes research in radiation dosimetry and health studies. Strongly promotes and participates in knowledge management activities within the agency in radiation protection.
Fuel and Source Term Code Development Branch
Chief: Richard Lee
Plans, develops, and manages research programs supporting risk-informed regulatory decision-making in fuels, neutronics, and severe accident and source term issues. Develops and maintains (i) computer codes to perform severe accident and source term analyses of postulated accidents at nuclear power plants and fuel cycle facilities, (ii) computer codes and data bases for neutronics analysis and assessing criticality safety for current, new, and advanced reactors, and spent fuel storage and transportation casks, (iii) computer codes to assess fuel and cladding performance under design basis accident (DBA) conditions and for auditing licensee's safety analyses, and (iv) computer codes to assess containment and reactor system performance for selected DBA and beyond-DBA safety analyses. These computer codes are used to perform quantitative assessment of safety in reactor operations and spent fuel transportation and storage, and to support design certification of new and advanced reactors. Also executes and/or participates in experimental programs to obtain data required to develop and validate fuel, neutronics and severe accident and source term codes. Knowledge management on fuel, neutronics and severe accident phenomena is carried out to preserve and distribute relevant information throughout the Agency. Provides consultation to NRC organizations in these specialized areas to enable reliable and technically sound regulatory decisions. Works in partnership with other NRC staff, universities, laboratories, and other national and international research centers involved in complementary areas. Lead for high-temperature gas-cooled reactor research.
Accident Analysis Branch
Chief: Patricia Santiago
Plans, develops, and manages analytical and experimental research projects on the progression, response, and offsite consequences of postulated severe accidents; and performs safety analyses of nuclear power plant systems. This work includes safety and security analyses; analyses of thermal-hydraulic transient behavior and interaction with the balance of plant under abnormal and accident conditions; and accident analyses beyond the reactor core, such as postulated accidents from spent fuel storage and transportation. State-of-the-art analytical techniques are used to develop realistic best estimates of the potential effects (consequences) to the public of low-likelihood nuclear power plant and spent fuel storage and transportation accidents which could release radioactive material into the environment. Models accident progression in order to estimate the magnitude and timing of radioactive release into the environment to estimate site-specific consequences (e.g. health effects). The experimental research projects support NRC's knowledge and understanding of severe accidents, and they support NRC's models with experimental data. Provides consultation to NRC offices regarding safety or licensing decisions, development of guidance, or other regulatory needs, and partners with USDOE, universities, laboratories, and other national and international research centers. Also manages the Agency long-term research program and research for advanced reactor designs, for example, liquid metal reactor (LMRs).
Division of Risk Analysis
Director: Richard Correia
Deputy Director: Patrick Madden
Develops, recommends, plans, and manages research programs relating to probabilistic risk assessments (PRA), human factors, and human reliability analysis. Assesses U.S. operational safety data and reliability information to determine risk-significant insights and trends. Coordinates research activities with the program offices, as appropriate. Develops and uses PRA-based methodologies, models, and analysis techniques, as well as other risk assessment techniques, to determine overall risk. Responsible for development of guidance and regulatory tools for implementation of the Safety Goal Policy and PRA Policy Statements. Performs risk and reliability analyses and evaluations based on operating experience to assess industry and plant performance and identify plant outliers. Develops and manages data systems for the storage and retrieval of safety experience. Remains cognizant of operational and reliability data systems in the industry and the NRC, and serves as focal point for coordination of the NRC safety data collection programs with external stakeholders. Provides an NRC focal point for the Equipment Performance and Information Exchange (EPIX) system and oversees the use of EPIX data by NRC users. Develops risk-informed performance indicators and thresholds to provide support to the agency's Reactor Oversight Program (ROP) and Industry Trends Program. Implements the Accident Sequence Precursor Program for operating nuclear power plants, including the production of periodic performance indicator and accident sequence precursor reports. Performs reliability studies for risk significant systems and equipment on operating nuclear power plants. Maintains staff capability by developing standardized plant risk models (SPAR) and a PRA Code to perform state-of-the-art operating experience risk analyses for both independent assessments and to assist other agency organizations in the assessment of licensee risk-related performance and safety issue risk implications. Performs a comprehensive review of operating experience and conducts in-depth analyses and evaluations of significant operating events and safety issues to determine root causes of these events. Manages GIs related to systems performance. Manages and coordinates fire safety research, including testing and developing risk analysis models. Maintains broad technical expertise and provides consultation to NRC organizations in PRA-related areas.
Probabilistic Risk Assessment Branch
Chief: Kevin Coyne
Plans, develops, integrates and manages research and development programs relating to probabilistic risk assessment (PRA) models and methods. Supports agency efforts to use risk information in all aspects of regulatory decision making, and undertakes specific initiatives as the lead organization. Coordinates research and development activities and PRA Standards with the other agency program offices and external partners (e.g., Universities, international organizations). Develops and uses PRA-based methodologies, models, and analysis techniques, such as the standardized plant risk models (SPAR), the SAPHIRE code and other PRA codes. Develops guidance and other regulatory tools for implementation of the Safety Goal and PRA Policy Statements. Provides safety perspectives on plant design and operation using probabilistic techniques to identify dominant risk contributors and potential risk management strategies. Maintains broad technical expertise and provides consultation to NRC organizations in PRA-related areas. Participates in international activities aimed at sharing PRA-related information. Recommends improvements in NRC programs/processes to achieve outcomes of enhanced safety, efficiency, and effectiveness.
Fire Research Branch
Chief: Mark Salley
Plans, develops, and manages the agency's fire safety research programs, including fire modeling, fire PRA risk analysis methods and fire testing programs. Supports other NRC offices such as NRR and NMSS by developing and validating fire analysis methodologies and supporting data. Provides workshops and seminars on using these state-of-the-art methods and tools. Using results of associated fire safety research, recommends improvements in NRC programs and/or processes to achieve outcomes of enhanced safety, efficiency or effectiveness, and risk informed regulations. Represents the agency in fire safety research initiatives with outside organizations (e.g. EPRI), on standards development committees, and international fire research risk/safety forums.
Operating Experience and Generic Issues Branch
Plans, develops and manages research programs to systematically assess U.S. operational safety data and reliability information for use in probabilistic risk assessments and to determine risk-significant trends. Performs risk and reliability analyses and evaluations based on operating experience to assess industry and plant performance and identify plant outliers. Develops and maintains operating experience data base systems for the storage and retrieval of safety experience. Provides the focal point and coordination for the NRC safety data collection programs with the industry, international organizations and other Federal agencies involved with data collection systems. Supports the agency's Operating Experience Program and Clearinghouse. Supports the use of Equipment Performance and Information Exchange (EPIX) data by NRC users in the assessment of the safety significance of licensee performance and safety issue risk implications. Implements the agency's Generic Issues Program (GIP). Ensures that the GIP is coordinated with other offices and programs to achieve consistent, agency-wide program implementation. Provides oversight, tracking, and reporting of Generic Issue status to effectively manage the program, achieve timeliness, and effectively communicate to stakeholders.
Performance and Reliability Branch
Chief: John Nakoski
Plans, develops and manages research programs to systematically assess reliability information to determine risk-informed insights for nuclear power reactors and other regulatory applications. Assists other agency program offices in the safety assessment of licensee performance and safety issue risk implications. Develops risk-informed performance indicators and thresholds to support the agency's Reactor Oversight Program (ROP). Implements the Accident Sequence Precursor (ASP) Program for operating nuclear power plants, including the production of ASP reports and input to the NRC Performance and Accountability Report. Conducts in-depth analyses and evaluations of significant operating events and safety issues to determine root causes of these events, risk insights and lessons-learned. Coordinates related research activities with the program offices, such as the Risk Assessment Standardization Project (RASP), as appropriate. Recommends improvements in NRC programs and/or processes to achieve outcomes of enhanced safety, efficiency or effectiveness. Coordinates Office efforts to apply risk information in revising and updating NRC regulations, regulatory guides, and the technical bases for NRC regulatory decisions (e.g., licensing reviews, inspection findings and enforcement).
Operating experience data is obtained from nuclear power plants via the Institute for Nuclear Power Operations and from Licensee Event Reports, Monthly Operating Reports, the Mitigating System Performance Index program and an insurance organization. The data is collected, reviewed for quality, categorized and evaluated. The evaluations produce insights for reactor inspectors, input parameters for probabilistic risk assessments and input for the Industry Trends and Accident Sequence Precursor Programs.
Human Factors and Reliability Branch
Chief: Sean Peters
Plans, develops, and manages research programs relating to human factors, human reliability analysis, and human performance. Coordinates research and development activities with the Program Offices and external partners (e.g., Universities, international organizations). Develops and uses human factors and human reliability analysis methodologies, models, and techniques to evaluate human performance. Provides safety perspectives on the impact of human performance on nuclear power plant operations and other NRC-licensed facilities and activities. Identifies potential human performance safety issues and assesses their significance. Maintains broad technical expertise and provides consultation to NRC organizations in human performance related areas. Identifies the need for and supports the development of human performance related training for NRC staff. Collects, reviews, and evaluates data and information relating to human performance, and develops and validates regulatory tools and guidance for use in evaluating human factors, performing human reliability analyses, and assessing human performance. Participates in international activities aimed at sharing human factors and human reliability-related information. Recommends improvements in NRC programs/processes to achieve outcomes of enhanced safety, efficiency, and effectiveness.
Environmental Transport Branch
Chief: William Ott
Develops the methods, data, standards, and modeling tools to assess the magnitude and effect of released radioactive material to the environment outside nuclear facilities. Develops and evaluates pathway models to assess contamination. Provides an assessment of source terms from releases. Develops and applies surface and subsurface process models for assessing transport of released radioactive material. Develops and applies integrated systems models for evaluating complex sites, including computational techniques and systems and probabilistic analyses. Evaluates the degradation and long-term performance of engineered barriers to radionuclide migration. Maintains expertise in Hydrology (both ground water and surface water), Geochemistry, Radiochemistry, Geotechnical Engineering, Materials Science, and Radiobiology to support NRC assessments of environmental effects of released radioactive materials.