Graded Approach to Application of Quality Assurance Controls at the Waste Isolation Pilot Plant

Abstract

ABSTRACT This paper documents Washington TRU Solution's LLC (WTS) reengineering initiative for the application of graded approach at the U.S. Department of Energy's (DOE) Waste Isolation Pilot Plant (WIPP), which is a non-reactor nuclear facility used for permanent disposal of transuranic (TRU) waste. In the early 1990s, the “graded approach” concept to the application of quality assurance (QA) controls was institutionalized. Early application of QA controls were based on the importance of the item, service, or activity to nuclear safety. While this continued to be a primary driver, the design classification of items, originally developed by Bechtel during the construction of the WIPP also continued as an important part of the initial quality–affecting determination. New guidance introduced by DOE G 420.1-11 advocated the application of quality controls to the design, fabrication, construction, and modification of systems, structures, and components (SSCs) based on their importance to nuclear safety as analyzed in the documented safety analyses. With the new guidance in mind, the WIPP Safety Analysis Group, in concert with the QA Department, adopted a methodology to assure that quality and safety were sufficiently integrated consistent with the new guidelines. Two procedural enhancements resulting from the effort include 1) Functional Classification Determination for Design, and 2) Quality–Affecting Determination. Correspondingly, the graded approach process was reengineered so that the foundation of the quality–affecting determination is dependent on deliberate quality planning and is based on facility–specific or activity–specific factors consistent with their importance to safety and functional classification. The newly adopted methodology expanded the application of graded approach beyond SSCs or items to include activities and services such as procurement and procedures. The methodology was formalized in a quality assurance implementing procedure and cross-referenced in site design, maintenance, and procurement procedures. As a result, WIPP's enhanced graded approach process provides an effective management system tailored to WIPP operations and activities through the deliberate and graded application of QA elements. Importantly, the integration of the reengineered graded approach process with other site management systems forms the basis for the WIPP Integrated Safety Management System (ISMS), which provides a formal, organized process to plan, perform, assess, and improve the safe conduct of work. As a management tool, the newly improved graded approach methodology enhances the ability of WIPP personnel to better determine the application of quality. The selected controls will be commensurate with importance and relative risk to safety, waste isolation, and regulatory compliance. 1Non-Reactor Nuclear Safety Design Criteria and Explosives Safety Criteria Guide for use with DOE O 420.A. Facility Safety.