Hazards Analysis, Code Compliance & Procedure Development

Services to identify process safety hazards and facilitate compliance with established standards and codes.

Combustible Dust Testing

Laboratory testing to quantify dust explosion and reactivity hazards

Flammable Gas & Vapor Testing

Laboratory testing to quantify explosion hazards for vapor and gas mixtures

Chemical Reactivity Testing

Laboratory testing to quantify reactive chemical hazards, including the possibility of material incompatibility, instability, and runaway chemical reactions

DIERS Methodology

Design emergency pressure relief systems to mitigate the consequences of unwanted chemical reactivity and account for two-phase flow using the right tools and methods

Deflagrations (Dust/Vapor/Gas)

Properly size pressure relief vents to protect your processes from dust, vapor, and gas explosions

Effluent Handling

Pressure relief sizing is just the first step and it is critical to safety handle the effluent discharge from an overpressure event

Thermal Stability

Safe storage or processing requires an understanding of the possible hazards associated with sensitivity to variations in temperature


Classification of hazardous materials subject to shipping and storage regulations

Safety Data Sheets

Develop critical safety data for inclusion in SDS documents


Model transport of airborne virus aerosols to guide safe operations and ventilation upgrades


Model transport of contamination for source term and leak path factor analysis

Fire Analysis

Model transport of heat and smoke for fire analysis

Flammable or Toxic Gas

transport of flammable or toxic gas during a process upset

OSS consulting, adiabatic & reaction calorimetry and consulting

Onsite safety studies can help identify explosibility and chemical reaction hazards so that appropriate testing, simulations, or calculations are identified to support safe scale up

Mechanical, Piping, and Electrical

Engineering and testing to support safe plant operations and develop solutions to problems in heat transfer, fluid flow, electric power systems

Battery Safety

Testing to support safe design of batteries and electrical power backup facilities particularly to satisfy UL9540a ed.4

Hydrogen Safety

Testing and consulting on the explosion risks associated with devices and processes which use or produce hydrogen

Spent Fuel

Safety analysis for packaging, transport, and storage of spent nuclear fuel

Decommissioning, Decontamination and Remediation (DD&R)

Safety analysis to underpin decommissioning process at facilities which have produced or used radioactive nuclear materials

Laboratory Testing & Software Capabilities

Bespoke testing and modeling services to validate analysis of DD&R processes

Nuclear Overview

Our Nuclear Services Group is recognized for comprehensive evaluations to help commercial nuclear power plants operate efficiently and stay compliant.

Severe Accident Analysis and Risk Assessment

Expert analysis of possible risk and consequences from nuclear plant accidents

Thermal Hydraulics

Testing and analysis to ensure that critical equipment will operate under adverse environmental conditions

Environmental Qualification (EQ) and Equipment Survivability (ES)

Testing and analysis to ensure that critical equipment will operate under adverse environmental conditions

Laboratory Testing & Software Capabilities

Testing and modeling services to support resolution of emergent safety issues at a power plant

Adiabatic Safety Calorimeters (ARSST and VSP2)

Low thermal inertial adiabatic calorimeters specially designed to provide directly scalable data that are critical to safe process design

Other Lab Equipment and Parts for the DSC/ARC/ARSST/VSP2 Calorimeters

Products and equipment for the process safety or process development laboratory


Software for emergency relief system design to ensure safe processing of reactive chemicals, including consideration of two-phase flow and runaway chemical reactions


Facility modeling software mechanistically tracks transport of heat, gasses, vapors, and aerosols for safety analysis of multi-room facilities


Our highly experienced team keeps you up-to-date on the latest process safety developments.

Process Safety Newsletter

Stay informed with our quarterly Process Safety Newsletters sharing topical articles and practical advice.


With over 40 years of industry expertise, we have a wealth of process safety knowledge to share.

Recent Posts

Level II Probabilistic Risk Assessments (PRA) for Nuclear Safety

Posted by The Fauske Team on 03.11.14

In the wake of the Fukushima Daiichi accident in Japan, nuclear power safety is under heightened scrutiny throughout the United States and worldwide. Fauske & Associates, LLC (FAI) utilizes Probabilistic Risk Assessments (PRA) to gauge the probability of risk by using calculations to determine the potential, probability and possible severity of an unwanted phenomena occurring in a nuclear power plant. FAI developed extensive capabilities and experience in performance of NRC classified Level II risk analysis specifically focused on the potential for accidents that could release radioactivity from a nuclear facility.

In the late 1980’s, FAI supported the nuclear industry response to the NRC’s Generic Letter 88-20 requirement that all nuclear facilities undergo a risk assessment for severe accident vulnerabilities termed as an Individual Plant Examination (IPE), assisting a large percentage of US utilities in the process. IPE updates included improvements to Level I success criteria, assessments of Large Early Release Frequencies (LERF), determination of Level II source term releases and assessments of plant vulnerabilities to severe accident phenomena. FAI also performed a number of key experiments to expand the understanding of severe accidents related to:PWR Containment Cross Sectional View

• Direct containment heating
• Drywell shell core debris interaction (liner melt-through)
• External cooling of the RPV
• Lower plenum penetration response
• Rapid pressurization due to steaming (steam explosions)
• In-vessel cooling
• Hydrogen control and management

The extensive Level II work performed by FAI is indicative of both a strong knowledge base and a high-quality organization," states Martin Plys, ScD, Vice President, Waste Technology & Post Fukushima Services, FAI. "Both in-house experiments and knowledge of experiments performed elsewhere have provided FAI professionals with an in-depth understanding of the broad technical basis developed for accident analyses including those focused on severe accident phenomena. This understanding is communicated through phenomenological position papers which become part of the living documentation. This, coupled with a staff of experienced engineers with hands-on nuclear power plant experience, positions FAI as the ideal choice for performing or assisting in Level II risk analysis."

The Modular Accident Analysis Program (MAAP4 and MAAP5) an Electric Power Research Institute (EPRI) owned and licensed computer software have been used to perform severe accident analysis and associated severe accident phenomena such as: hydrogen generation and combustion, direct-containment heating, rapid pressurization due to steaming, core concrete interactions, fission product releases, transport and deposition, for many decades. These codes are also used extensively in the probabilistic risk/safety assessment (PRA/PSA) arena as well as for applications including success criteria evaluations, human reliability analyses (HRA) and Level II source term evaluations.

FAI was also the principal author of the original Severe Accident Management (SAM) Technical Basis Report (TBR - EPRI TR-101869). This report provided the technical bases upon which the PWR (Pressurized-Water Reactor) Owners Groups at the time (Westinghouse, Combustion Engineering and Babcock & Wilcox) developed generic severe accident management guidance SAMG) support material, which served as a framework for each utility’s plant-specific SAMG program. In the aftermath of the Fukushima accident, EPRI commissioned an update to the original TBR, and FAI was once again a principal author of this update. In addition to the immediate insights from the Fukushima accident, the TBR update also incorporates a significant amount of research and experimental information that post-dated the original TBR.

While FAI leveraged its severe accident technical basis experience within the SAM TBR in its post-TMI and post-Fukushima evolutions, Westinghouse Electric Company, LLC (In 1986, FAI became a wholly owned subsidiary), focused on implementation of the TBR into the actual plant-specific SAMG implementation programs for customer sites. Thus, FAI and Westinghouse have maintained complementary SAMG capabilities which can be utilized to assist customers with preparing for NRC inspections. Due to the diversity of skills across FAI’s engineering staff, the company specializes in many functional areas within the nuclear power and decontamination/decommissioning industries including:

Corium Pool• General Thermal Hydraulics Analysis
• Fluid System-Specific Transient Analysis
• Two-Phase Critical Flow
• Waterhammer and Related Hydrodynamics
• High-Pressure Subcooled Jet Depressurization and Jet Impingement
• One-Phase Plume and Jet Mixing Analysis
• Building Analysis (Primary Containment, Reactor Building, Auxiliary Building)
• Software Development
• NRC Regulations and FAI Supporting Skill Set
• Industry Flexible and Diverse (FLEX) Strategy for Extended SBO
• BWR High-Reliability Hardened Vent Support
• Spent Fuel Pool Monitoring (SFPIS)
• Containment Filtered Vent Support
• Hydrogen Generation, Monitoring and Control
• Severe Accident Management
• Probabilistic Risk Assessment (PRA)

Founded in 1980 by Drs. Hans Fauske, Robert Henry and Michael Grolmes, FAI is a world leader in nuclear, industrial and chemical process safety. For more information on PRA, MAAP, severe accident analysis or other nuclear power safety concerns, please contact Dr. Martin Plys: plys@fauske.com or 630-887-5207

Subscribe to FAI's "Nuclear Technical Bulletins"

Topics: severe accident, MAAP, nuclear safety, nuclear power, PWR Owners Group, Probabilistic Safety Assessment, nuclear


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