AN EXPLORATORY STUDY OF PROTECTION AGAINST NUCLEAR THERMAL RADIATION WITH SMOKING AND INTUMESCENT PAINTS
An exploratory laboratory investigation was made on protection against nuclear thermal radiation with thermoshielding and intumescent paints. Thermoshield ing paint, a new invention, protects by interposing a rapidly produced, self-generated smoke screen between substrate and radiation. Intumescent paint, commercially available, protects by expanding into a heat- insulating, sponge-like mat. Three experimental, prototype thermoshielding paints were invented, and one intumescent palnt, Albi-99, was selected for study. The former consisted of Nawy gray paint having tetracene (i.e., 1granyl-4- nitrosoaminoguanyltetrazene), nitrosoquanidine or sebacic acid as smoke- generating components. The paints were applied on thin, 3/4-in. diameter, primered copper discs. These were subjected to square-wave and simulated weapon pulse exposures with the Mitchell thermal radiation source, and curves of temperature rise versus time after incidence were determined. Degree of protection was evaluated relative to ordinary Navy gray paint, and was expressed numerically for any particular time after incidence as a percentage (A-B)/ (A) x 100, where A represents the temperature rise of the Navy gray paint disc, and B that of the test palnt disc. The degree of protection varied with paint and exposure characteristics. The thermoshielding sebacic acid paint protected appreciably (7 to 16%) throughout a range of simulated weapon exposures extending from one of high peak irradiance and moderate yield (22 cal/cm/sup 2/ sec and 0.2 Mt) to one of low peak irradiance and high yield (5 cal/cm/sup 2//sec and 10 Mt). The explosively decrepitating thermoshielding paints, tetracene and nitrosoguanidine, protected appreciably (13 to 19%) when the simulated weapon pulses delivered the majority of the radiation within a few seconds, but they failed to protect when the majority was delivered during a period of many seconds. Intumescent Albi-99 protected appreci-ably (7 to 23%) when temperature rises were great enough (about 225 to 250 deg C) for formation of its relatively slowly produced foam blanket, but it failed completely for large, vary rapid temperature rises since immediate decomposition then caused loss of the intumescent property. All paints showed appreciable, sustained protection at exposures corresponding to 22 cal/cm/sup 2//sec peak irradiance and 1-Mt yield: sebacic acid paint, 14%; tetracene and nitrosoguanidine paints, 19%; Albi-99 paint, 23%. (auth)
- Research Organization:
- Naval Radiological Defense Lab., San Francisco
- NSA Number:
- NSA-12-012041
- OSTI ID:
- 4301997
- Report Number(s):
- USNRDL-TR-241
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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