About Us

Innovative Systems Software

Advancing Reactor Safety Analysis Since 1996

Company Overview

Innovative Systems Software, LLC (ISS) is a distinguished limited liability company, established in 1996, that specializes in advancing reactor safety analysis and simulation technologies. The organization orchestrates the SCDAP Development and Training Program, a global consortium committed to the enhancement of reactor safety through research, regulatory efforts, and collaborative initiatives.

ISS is globally recognized for its exceptional contributions to reactor safety analysis and the development of thermal-hydraulic systems analysis software. The foundation of the company by Dr. C. Allison, who spearheaded the SCDAP/RELAP5 severe accident code development at the Idaho National Engineering and Environmental Laboratory (INL) from 1981 to 1996, underscored ISS's commitment to excellence.

Dr. Allison's consultancy roles with the U.S. Nuclear Regulatory Commission (USNRC), Department of Energy (USDOE), and International Atomic Energy Agency (IAEA) further accentuate the firm's authoritative standing in the field.

Our Core Values

The principles that guide our work in nuclear safety

Safety First

We are dedicated to enhancing nuclear safety through accurate, reliable analysis tools that meet the highest industry standards.

Innovation

Continuously advancing our software capabilities to address evolving challenges in the nuclear industry.

Reliability

Providing dependable software solutions backed by rigorous validation and decades of proven performance.

Global Collaboration

Working with international partners to advance nuclear safety research and regulatory efforts worldwide.

Our Team

Experienced professionals dedicated to nuclear safety excellence

Dr. Chris Allison

Dr. Chris Allison

General Manager

Founder of ISS and pioneer in SCDAP/RELAP5 severe accident code development at Idaho National Engineering and Environmental Laboratory (INL) from 1981 to 1996.

Dr. Raimon Pericas

Dr. Raimon Pericas

RELAP5/SCDAP Researcher & System Engineer

Expert researcher specializing in RELAP5/SCDAP modeling and system engineering for advanced thermal hydraulic analysis.

Dr. Marina Perez-Ferragut

Dr. Marina Perez-Ferragut

ENSO

Uncertainty Analysis Developer

Expert in uncertainty analysis and model development training, specializing in advanced statistical methods for reactor safety.

Brian Allison

Brian Allison

IT/Programmer

Information technology specialist and computer programming expert, managing ISS's technical infrastructure and software development.

Dr. Victor Martinez-Quiroga

Dr. Victor Martinez-Quiroga

ENSO

Associate Professor

Associate Professor at the Technical University of Catalonia, bringing academic excellence and research expertise to the team.

Former Key Personnel

R. Wagner: Lead architect of the RELAP5 code at INL, served as lead programmer for RELAP/SCDAPSIM from May 1998
L. Siefken: Specialized in Fuel Behavior and SCDAP Modeling

Global Impact & Reach

Leading international collaboration in reactor safety analysis and simulation technologies

34+

Countries

ISS proudly administers the SCDAP and ASYST Development and Training Programs (SDTP/ADTP), an international consortium comprising over 100 research, regulatory, and diverse organizations spanning more than 34 countries worldwide.

100+

Global Organizations

Our collaborative endeavor brings together research institutions, regulatory bodies, and industry leaders dedicated to advancing reactor safety analysis and simulation technologies.

40+

Years of Experience

The ISS team excels in reactor safety and thermal-hydraulic software development, gaining global recognition as industry leaders since the early 1980s.

Why Choose ISS?

Our expertise, experience, and commitment to excellence make us the preferred choice for nuclear safety analysis

SDTP/ADTP Consortium

Leading global programs across 34+ countries

Industry Standard

RELAP5/SCDAPSIM is the gold standard

Expert Support

Comprehensive training and assistance

Innovation Leader

Continuous advancement in safety technology

Industry Affiliations & Recognition

ISS maintains strong relationships with the U.S. Nuclear Regulatory Commission (USNRC), Department of Energy (USDOE), International Atomic Energy Agency (IAEA), and numerous research institutions worldwide. Our software and expertise are recognized as essential tools for nuclear safety analysis and regulatory compliance.