|Tank Waste Remediation System (TWRS)
A vitrification melter is a key component of
the processing system.
|Probabilities of accidents
postulated in a safety case versus actual accidents were used for
recommending acceptable accident frequencies.
Statement of Problem: Provide
technical assistance and bases necessary for the development of
regulatory framework and associated guidance that can be used to support
regulation of TWRS-P Phase II waste solidification (vitrification)
operations based on 10 CFR Part 70.
Approach and Accomplishments: This
program was structured into two parts:
1) Developed technical documents that
provided the most current information of the waste solidification plant
operations and safety issues, chemistry of waste in tanks and molten
glass, evaluation of plant consequences based on 10 CFR Part 70 and
standard review plan for TWRS.
2) Assisted the U.S. Nuclear Regulatory
Commission staff in technical and
regulatory reviews of Department of Energy (DOE) contractor documents,
identified technical uncertainties and potential safety issues, and
performed independent evaluations of proposed technologies or
calculations used by the DOE contractor to support the safety case.
This task included review of (i) process flow diagrams and designs, (ii)
radionuclide inventories in tanks and criticality analyses, (iii)
preliminary hazard analysis, (iv) initial safety analysis, (v) design
safety features such as hydrogen
generation in waste tanks, (vi) fire hazard analysis, (vii) management
of risks posed by explosive and chemical hazards such as steam or sugar
dust explosions and nitrate/organic reactions, (viii) preliminary design
basis events, (ix) compliance with risk goals and project reliability
CNWRA® staff with experience in high-level
waste solidification process design and operations, fire technology,
health physics, risk analysis, corrosion engineering, chemical
engineering, facility design engineering, nuclear criticality, and
performance assessment were used to accomplish the task.
Client Benefits: The concerted
efforts of a multi-disciplinary team at CNWRA provided, on schedule,
evaluations and recommendations on technical uncertainties and potential
safety issues associated with the proposed technologies or calculations
used by the DOE contractor to support the safety case.