CONTAINMENT OF FRAGMENTS FROM A RUNAWAY REACTOR. Summary Progress Report No. 2 for Period November 1, 1959-April 30, 1960
In order to extend earlier studies to longer periods which would overlap SPERT data, development of new energy sources was undertaken. This development of low-velocity high-energy explosive has had substantial success. Velocities in the vicinity of 1000 meters per second were obtained and measured by a variety of techniques. Even lower velocities appear feasible. Calorimetric measurements indicate more than adequate energy yield. Simulated reactor periods up to 20 msec should be possible with this explosive. Study of reactor model response to simulated runaways was extended to include additional reactor features, many of which were found to have significant influence on the response. Energy sources with entirely gaseous reaction products produced considerably greater fragmentation and fragment throw than sources with partly solid products. Magnitude of pressure pulses delivered by the source is responsible for the difference. Lowering the energy release rate from a 1- to 2-msec period results in substantial reduction of damage produced by the release. Simulated thermal shielding between model reactor vessel and model biological shielding allows an appreciable fraction of energy to be absorbed by the vessel wall or the shielding itself, reducing damage to the concrete. Reduction of concrete shielding thickness by 25% results in a large increase in shielding fragmentation. Lack of confinement of vessel contents (no lid on vessel) had little effect on damage produced in model excursions. Approximate calculations of pressure rise inside the model reactor vessel gave a maximum value of 13,000 psi for any of the model energy releases currently in use. Actual pressures are expected to be lower because of several processes, neglected in the calculations, that absorb minor amounts of energy. Studies, both experimental and analytical, of steel plate penetration were extended. Apparatus for prestressing small-scale target plates was designed and constructed. Preliminary penetration experiments with the apparatus showed that a measurable reduction in penetration resistance can be produced by prestressing the target. In small-scale tests, penetration was achieved in moderately stressed plates with projectile energies reduced as much as 11%-compared with energies required to penetrate unstressed targets. Penetration tests with large steel projectiles of 1-in.thick targets that conform to the specifications for steel in reactor vapor container shells indicated at least 20% lower resistance to penetration than low-carbon aluminum-killed mild steel which had fine grain structure and 30% lower tensile strength. These results indicated that current standards are not sufficient to indicate dynamic resistance of steel. Penetration tests of ordinary mild steel with large concrete projectiles showed that neither enhanced dynamic compressive strength nor sevenfold excess in kinetic energy over that required of steel projectiles is effective for achieving penetration. Calculations indicated that a con crete missile diameter greater than 2 ft is necessary for the missile to penetrate 1- in. steel plate. (For preceding period see SRIA-2.) (auth)
- Research Organization:
- Stanford Research Inst. Poulter Labs., Menlo Park, Calif. Page(s): 104
- DOE Contract Number:
- AT(04-3)-115
- NSA Number:
- NSA-15-007031
- OSTI ID:
- 4105353
- Report Number(s):
- SRIA-25
- Resource Relation:
- Other Information: Project No. 2. Orig. Receipt Date: 31-DEC-61
- Country of Publication:
- United States
- Language:
- English
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