Process Parameter

DOE-STD-3007-2007

PROCESS PARAMETER a physical property whose value affects the nuclear reactivity of a system.

Parameters include the mass, density, concentration, and isotopic enrichment of fissionable material; the

geometry, reflection, and interaction conditions of the system; and the moderation, composition and

neutron absorption characteristics of the fissionable material mixture and other system materials.

UNLIKELY the attribute of being improbable on the basis of commonly acceptable engineering

judgment. An unlikely event is an event that is not expected to occur more than once in the lifetime of a

facility. Due to the general lack of statistically reliable data, assigning numerical probabilities to events is

not usually justifiable and when used should be backed up with references.

ACRONYMS

CAAS

Criticality Accident Alarm System

CCR

Criticality Control Review

CSE

Criticality Safety Evaluation

CSP

Criticality Safety Program

DOE

Department of Energy

DSA

Documented Safety Analysis

NCS

Nuclear Criticality Safety

NCSP

Nuclear Criticality Safety Program

SSC

Structures, Systems or Components

TSR

Technical Safety Requirement

USQ

Unreviewed Safety Question