CHME 491. Special Topics – Introduction to Nuclear Criticality Safety

1. Course number and name

CHME 491. Special Topics – Introduction to Nuclear Criticality Safety 

2. Credits and contact hours

3 credit hours = 45 contact hours per semester

3. Instructor’s or course coordinator’s name

Alicia Salazar-Crockett and Andrew Wysong 

4. Text book, title, author, and year

Nuclear Criticality Safety Theory and Practice, Ronald Allen Knief, American Nuclear Society Publishing (2000)

a. other supplemental materials

  • LA-14098 – Modern Fission Theory for Criticality by J. Eric Lynn
  • LA-14244-M – Hand Calculation Methods for Criticality Safety – A Primer by Douglas G. Bowen and Robert D. Busch
  • LA-13638 – A Review of Criticality Accidents (2000 Revision) by Thomas P. McLaughlin, Shean P. Monahan, and Norman L. Pruvost

5. Specific course information

a. catalog description:  : Introduction to the concepts and practice of nuclear criticality safety. Includes an introduction to nuclear physics, overview of criticality safety accidents, Orders/Standards applicable to criticality safety. Introduction to hand calculations and Monte Carlo methods used in criticality safety analysis. Application of skills learned in preparation of criticality safety evaluation.

b. prerequisites: none co-requisites: none

c. required, elective, or selected elective (as per Table 5-1): elective

6. Specific goals for the course

a. The student will be able to…

  • Define the following terms: Excitation energy, Cross Section, Fissile material, Fissionable Material, Fertile Material.
  • Sketch the fission cross section for both U-235 and Pu-239 as a function of neutron energy. Label each significant energy region and explain the implications of the shape of the curves for criticality safety.
  • Explain why only the heaviest radioactive nuclear are easily fissioned.
  • Define sub-critical, critical, super-critical, nu, and beta.
  • Define nuclear reactivity and describe how it is measured.
  • Explain the effects of the following factors relevant to criticality safety of operations: Mass, Interaction, Geometry, Moderation, Reflection, Concentration, Volume, Neutron absorbers and Enrichment.
  • Describe the interactions of the following with matter: Alpha particle, Beta particle, Positron, and Neutron.
  • Describe the use of neutron poisons.
  • Explain the absorption characteristics of the following elements in terms of their cross-sections: cadmium, boron, chlorine, gadolinium, and hydrogen.
  • Identify and discuss the application of several common hand calculation methods.
  • Select one hand calculation technique (buckling, solid angle, or areal density) and prepare an example of its use.
  • Describe how cross section data impact Monte Carlo and deterministic codes.
  • Describe the importance of validation of computer codes and how it is accomplished.
  • Describe the methodology supporting Monte Carlo codes and deterministic codes.
  • Describe the types of data derived from critical experiments and their use in criticality safety.
  • Discuss previous criticality accidents and their causal factors, including parameters involved in solution and metal critical accidents.
  • Discuss ANSI/ANS-8.1, Nuclear Criticality Safety in Operations with Fissionable Materials Outside Reactors.
  • Discuss ANSI/ANS-8.19, Administrative Practices for Nuclear Criticality Safety.
  • Discuss ANSI/ANS-8.21, Use of Fixed Neutron Absorbers in Nuclear Facilities
Outside Reactors.
  • Discuss ANSI/ANS-8.26, Criticality Safety Engineer Training and Qualification Program.
  • Discuss DOE Order 420.1C, FACILITY SAFETY, Section 4.3, Nuclear Criticality Safety
  • Discuss DOE-STD-3007-2007 Guidelines for Preparing Criticality Safety Evaluations at Department of Energy Non-Reactor Nuclear Facilities.
  • Discuss LA-10860-MS, Critical Dimensions of Systems Containing U235, Pu239, and 
U233, 1986. 
  • Discuss TID-7016, The Nuclear Safety Guide, June 1978.
  • Develop contingency analysis, limits and controls.
  • Describe key personnel needed to assist in preparation of criticality safety evaluations and determination of process upsets.
  • Describe how subcritical margins and limits are determined.
  • Describe typical criteria to consider when evaluating various fissile processes, including common process upsets: Aqueous, Metal, Recovery, Fabrication/Foundry, Mixed Waste.
  • Discuss the methods used in the calculation of criticality safety, source term, environmental transport, and dose assessment activities including commonly used computer models.
  • Identify and discuss essential elements of deterministic and probabilistic risk assessment techniques.
  • Identify and discuss the methods used to determine and analyze failure modes.
  • Explain how natural phenomenon events are evaluated in NCS.
  • Discuss LA-13638, A Review of Criticality Accidents, 2000 Revision

b. Criterion 3 Student Outcomes specifically addressed by this course are found in a mapping of outcomes against all CHME courses in the curriculum.

7. Brief list of topics to be covered

  • Introduction to Nuclear Criticality Safety
  • Introduction to Nuclear Physics
  • Criticality Safety Accidents
  • DOE Orders
  • ANSI/ANS Standards
  • Hand Calculations for Criticality Safety Analysis
  • Monte Carlo Methods for Criticality Safety Analysis
  • Criticality Safety Evaluations – Process Description
  • Criticality Safety Evaluations – Hazards Analysis
  • Criticality Safety Evaluations – Analysis (Handbooks/Experimental Data)
  • Criticality Safety Evaluations – Calculations
  • Review/Intro to Additional Topics (Critical Experiments, CAAS, etc)

Common Syllabus Addendum

The NMSU Department of Chemical Engineering maintains a syllabus addendum containing course requirements common to all courses with the CH E prefix online.  This document is accessible from the URL: