SciTech Connect

Title: Riola release report

Riola release report Eleven hours after execution of the Riola Event (at 0826 PDT on 25 September 1980) in hole U2eq of the Nevada Test Site (NTS), a release of radioactivity began. When the seepage stopped at about noon the following day, up to some 3200 Ci of activity had been dispersed by light variable winds. On 26 September, examination of the geophone records showed six hours of low-level, but fairly continuous, activity before the release. Electrical measurements indicated that most cables were still intact to a depth below the stemming platform. A survey of the ground zero area showed that the seepage came through cracks between the surface conductor and the pad, through cracks in the pad, and through a crack adjacent to the pad around the mousehole (a small hole adjacent to the emplacement hole). To preclude undue radiation exposure or injury from a surprise subsidence, safety measures were instituted. Tritium seepage was suffucient to postpone site activities until a box and pipeline were emplaced to contain and remove the gas. Radiation release modeling and calculations were generally consistent with observations. Plug-hole interaction calculations showed that the alluvium near the bottom of the plug may have been overstressed and that improvements more » in the design of the plug-medium interface can be made. Experimental studies verified that the surface appearance of the plug core was caused by erosion, but, assuming a normal strength for the plug material, that erosion alone could not account for the disappearance of such a large portion of the stemming platform. Samples from downhole plug experiments show that the plug may have been considerably weaker than had been indicted by quality assurance (QA) samples. 19 references, 32 figures, 10 tables. « less
Authors:
Publication Date:
OSTI Identifier:5301654
Report Number(s):UCRL-53437
ON: DE84005750
DOE Contract Number:W-7405-ENG-48
Resource Type:Technical Report
Data Type:
Resource Relation:Other Information: Portions are illegible in microfiche products. Original copy available until stock is exhausted
Research Org:Lawrence Livermore National Lab., CA (USA)
Country of Publication:United States
Language:English
Subject: 45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE; 54 ENVIRONMENTAL SCIENCES; BOREHOLES; FAILURES; NEVADA TEST SITE; NUCLEAR EXPLOSIONS; RADIOACTIVE EFFLUENTS; FISSION PRODUCTS; GASEOUS WASTES; SEALS; TRITIUM; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; CAVITIES; EXPLOSIONS; HYDROGEN ISOTOPES; ISOTOPES; LIGHT NUCLEI; MATERIALS; NATIONAL ORGANIZATIONS; NUCLEI; ODD-EVEN NUCLEI; RADIOACTIVE MATERIALS; RADIOACTIVE WASTES; RADIOISOTOPES; US DOE; US ORGANIZATIONS; WASTES; YEARS LIVING RADIOISOTOPES 450202* -- Explosions & Explosives-- Nuclear-- Weaponry-- (-1989); 500300 -- Environment, Atmospheric-- Radioactive Materials Monitoring & Transport-- (-1989)