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Title: Type B investigation of the iridium contamination event at the High Flux Isotope Reactor on September 7, 1993

Abstract

On the title date, at ORNL, area radiation alarms sounded during a routine transfer of a shielding cask (containing 60 Ci{sup 192}Ir) from the HFIR pool side to a transport truck. Small amounts of Ir were released from the cask onto the reactor bay floor. The floor was cleaned, and the cask was shipped to a hot cell at Building 3047 on Oct. 3, 1993. The event was caused by rupture of one of the Ir target rods after it was loaded into the cask for normal transport operations; the rupture was the result of steam generation in the target rod soon after it was placed in the cask (water had entered the target rod through a tiny defect in a weld while it was in the reactor under pressure). While the target rods were in the reactor and reactor pool, there was sufficient cooling to prevent steam generation; when the target rod was loaded into the dry transport cask, the temperature increased enough to result in boiling of the trapped water and produced high enough pressure to result in rupture. The escaping steam ejected some of the Ir pellets. The event was reported as Occurrence Report Number ORO--MMES-X10HFIR-1993-0030, datedmore » Sept. 8, 1993. Analysis indicated that the following conditions were probable causes: less than adequate welding procedures, practices, or techniques, material controls, or inspection methods, or combination thereof, could have led to weld defects, affecting the integrity of target rod IR-75; less than adequate secondary containment in the cask allowed Ir pellets to escape.« less

Publication Date:
Research Org.:
Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
10139742
Report Number(s):
DOE/OR-2004; ORNL/M-3175
ON: DE94009446; TRN: 94:007530
DOE Contract Number:  
AC05-84OR21400
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Mar 1994
Country of Publication:
United States
Language:
English
Subject:
22 GENERAL STUDIES OF NUCLEAR REACTORS; 07 ISOTOPES AND RADIATION SOURCES; IRIDIUM 192; ISOTOPE PRODUCTION; RADIATION ACCIDENTS; HFIR REACTOR; FAILURE MODE ANALYSIS; TARGETS; CASKS; CONTAMINATION; 220900; 220600; 070500; REACTOR SAFETY; RESEARCH, TEST, TRAINING, PRODUCTION, IRRADIATION, MATERIALS TESTING REACTORS; HEALTH AND SAFETY

Citation Formats

. Type B investigation of the iridium contamination event at the High Flux Isotope Reactor on September 7, 1993. United States: N. p., 1994. Web. doi:10.2172/10139742.
. Type B investigation of the iridium contamination event at the High Flux Isotope Reactor on September 7, 1993. United States. https://doi.org/10.2172/10139742
. 1994. "Type B investigation of the iridium contamination event at the High Flux Isotope Reactor on September 7, 1993". United States. https://doi.org/10.2172/10139742. https://www.osti.gov/servlets/purl/10139742.
@article{osti_10139742,
title = {Type B investigation of the iridium contamination event at the High Flux Isotope Reactor on September 7, 1993},
author = {},
abstractNote = {On the title date, at ORNL, area radiation alarms sounded during a routine transfer of a shielding cask (containing 60 Ci{sup 192}Ir) from the HFIR pool side to a transport truck. Small amounts of Ir were released from the cask onto the reactor bay floor. The floor was cleaned, and the cask was shipped to a hot cell at Building 3047 on Oct. 3, 1993. The event was caused by rupture of one of the Ir target rods after it was loaded into the cask for normal transport operations; the rupture was the result of steam generation in the target rod soon after it was placed in the cask (water had entered the target rod through a tiny defect in a weld while it was in the reactor under pressure). While the target rods were in the reactor and reactor pool, there was sufficient cooling to prevent steam generation; when the target rod was loaded into the dry transport cask, the temperature increased enough to result in boiling of the trapped water and produced high enough pressure to result in rupture. The escaping steam ejected some of the Ir pellets. The event was reported as Occurrence Report Number ORO--MMES-X10HFIR-1993-0030, dated Sept. 8, 1993. Analysis indicated that the following conditions were probable causes: less than adequate welding procedures, practices, or techniques, material controls, or inspection methods, or combination thereof, could have led to weld defects, affecting the integrity of target rod IR-75; less than adequate secondary containment in the cask allowed Ir pellets to escape.},
doi = {10.2172/10139742},
url = {https://www.osti.gov/biblio/10139742}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Mar 01 00:00:00 EST 1994},
month = {Tue Mar 01 00:00:00 EST 1994}
}