ANS Whitepaper Background
In 2001, the NCSD Executive Committee endorsed use of whitepapers to relate guidance on pertinent issues or examples of good practices in the practice of Nuclear Criticality Safety. The whitepaper process is intended to be a venue for all members of the division to promote best practices, lessons learned or to explore meaningful discussions on issues of importance to the criticality safety community. Whitepapers are intended to be living documents that could and should change as practices improve.
The white paper begins with a relevant subject matter or guidance topic that could add value to ANS NCSD. Once the Education Committee agrees to work on the topic, volunteers are assigned to draft the white paper.
Introduction This document presents an overview of the American Nuclear Society (ANS) Nuclear Criticality Safety Division (NCSD) Education Committee and delineates the white paper process lifecycle.
One of the more important tasks of a criticality safety engineer (CSE) is early design evaluation of proposed fissile material processes and facilities. The overall evaluation and selection of structures, systems, and components used for nuclear criticality safety (NCS) control purposes for a complex facility is a highly interactive and iterative process. Appropriate interaction with diverse engineering disciplines (chemical, process, radiological, structural, fire, MC&A, etc.) should be balanced to assure the established NCS control scheme is optimal for safety and operations and can be reliably maintained. Engineered control functionality and parameter selection and constraints can also affect process efficiency and facility operational cost structure. Therefore it is important that NCS practitioners engage project / process engineering management throughout the design process. NCS evaluations performed during design evolution should establish appropriate subcritical limits and controlled parameters. NCS control types used (e.g, passive, active and administrative) on said parameters must assure that an acceptable margin of subcriticality is maintained during normal operations, maintenance, and credible accident conditions.
One of the more difficult tasks of a criticality safety engineer (CSE) is to develop the rationale for the establishment of controlled parameters and the proper documentation of the basis for subcritical limits derived for the controlled parameters. In addition, clear specifications of associated control and functionality requirements to safely operate a process or facility that contains fissile material must be clearly communicated to operating personnel.
One of the more difficult tasks of a criticality safety engineer (CSE) is to develop the rationale for the establishment of controlled parameters and the proper documentation of the basis for nuclear criticality safety limits derived for the controlled parameters. In addition, clear specifications of associated control and functionality requirements to safely operate a process or facility that contains fissile material must be clearly communicated to operating personnel.
The Nuclear Criticality Safety Division (NCSD) urges and encourages the use of realistic models and assumptions in all studies of the risks, costs, benefits, and consequences related to establishing criticality safety in operations with fissionable material outside reactors.
As the Nuclear Criticality Safety Community grows older and large numbers of experienced criticality safety engineer specialists retire, there is a need for young aspiring criticality safety engineer specialists to fill the gap. It is very important that the lessonslearned over the past ~50 years are passed on to the “next generation.” This can be effectively accomplished utilizing a nuclear criticality safety mentorship program. A more experienced criticality safety engineer specialist (i.e., Mentor) should educate the lesserexperienced criticality safety engineer specialist (e.g., Trainee, or Engineer). Mentorship should not end once the Criticality Safety Trainee becomes a qualified Criticality Safety Engineer or Senior Criticality Safety Engineer at his/her nuclear facility. It is an ongoing, continuous process while an active member of the Nuclear Criticality Safety profession.
This fact sheet provides information on nuclear criticality accidents that have occurred since the beginnings of the nuclear industry with primary focus on those that have occurred in the workplace.
As more people become involved in nuclear criticality safety without having the experience of working handson with fissile materials, it is apparent that what a criticality safety engineer specialist is and what one does are not well understood. Therefore, it is important to have a common understanding of the definition of a criticality safety engineer specialist.
There is a need for a documented training and qualification program for new criticality safety engineer specialists at nuclear facilities. The need is being driven by (1) the emphasis on nuclear criticality safety, as nuclear facilities continue to undergo process modifications to support their respective missions; (2) regulatory agencies (e.g., U.S. Department of Energy, U.S. Nuclear Regulatory Commission, IAEA); and (3) the lack of a source of trained criticality safety engineer specialists from the universities.