Hazards Summary Report for the Reflector-Control Critical-Assembly Experiments

Technical Report · Tue Feb 12 04:00:00 EST 1957

DOI:https://doi.org/10.2172/4281556· OSTI ID:4281556

Jankowski, Francis J. ^[1]; Hogan, William S. ^[1]; Redmond, Robert F. ^[1]; Chastain, Joel W. ^[1]; Fawcett, Sherwood L. ^[1]

---

1. Battelle Memorial Inst., Columbus, OH (United States)

Critical experiments are described, and the hazards attendant to these experiments are evaluated for a reflector-controlled boiling-heterogeneous-reactor design. The proposed reactor design is water moderated and reflected. However, to provide maximum flexibility and safety, the critical assembly is a thermal reactor moderated and reflected with plastic having appropriate voids to simulate water. A section of the plastic reflector is movable to represent changes in the water-reflector level. The data obtained using this reflector-controlled assembly is then supplied to an electronic reactor simulator which is connected to a full-scale mock-up of the proposed hydraulic control system. In this manner, the characteristics of the complete system are determined. The fuel-element assemblies are composed of strips of aluminum and Teflon-coated uranium sandwiched with plastic and encased in aluminum boxes. One-half of the core is on a movable table, while the other half is on a fixed table. Primary control and safety of the assembly is achieved by inserting or withdrawing sandwiched stainless steel-cadmium regulating and safety plates and by increasing or decreasing the distance between the two core halves. For safety, the maximum normal rate of reactivity addition has been limited to an estimated 0.04 per cent per sec for control-rod withdrawal, table closure, or reflector movement. The system is interlocked so that only one rod can be withdrawn at a time and so that the movable table and rods cannot be moved simultaneously. In addition, criticality cannot be reached by moving the tables together. The scram system can insert all the rods in about 0.4 spec. Hazards calculations are made to determine the dosage from direct irradiation, fall-out, and inhalation from a radioactive cloud resulting from an accident. The exclusion area is shown to be adequate for even the maximum hypothetical accident.

• Research Organization: Battelle Memorial Inst., Columbus, OH (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP); US Atomic Energy Commission (AEC)
• DOE Contract Number: W-7405-ENG-92
• NSA Number: NSA-13-010625
• OSTI ID: 4281556
• Report Number(s): BMI-1166
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACCIDENTS
ALUMINUM
ANALOG SYSTEMS
Analysis
CADMIUM
CONFIGURATION
CONTROL
CONTROL SYSTEMS
COOLANTS
CRITICAL ASSEMBLIES
CRITICALITY
Configuration
Criticality
Experiments
FALLOUT
FLUORINATED HYDROCARBONS
FUEL CANS
FUEL ELEMENTS
HYDRAULICS
Hazard Calculations
JACKETS
MECHANICAL STRUCTURES
MOCKUP
NUMERICALS
Nuclear Criticality Safety Program (NCSP)
ORGANIC FLUORINE COMPOUNDS
PLATES
POLYMERS
RADIATION DOSES
RADIATION INJURIES
REACTIVITY
REACTOR CORE
REACTOR SAFETY
REACTORS
REFLECTORS
Reactor
STAINLESS STEELS
Safety
TEFLON
Teflon
URANIUM
WATER
WATER COOLANT
WATER MODERATOR