Reported Incidents Involving Spent Nuclear Fuel Shipments
1949 to Present

May 6, 1996

There have been 72 reported incidents involving spent nuclear fuel shipments from 1949 to present.

• From 1949 to 1970 14 incidents were reported in a series of U.S. Atomic Energy Commission reports. They were either traffic accidents with no releases or nontraffic accident events with minor leaks suspected from the casks which resulted in small amounts of observed contamination.

• From 1971 to present, 58 incidents have been reported in the Radioactive Material Incident Report database operated by Sandia National Laboratories. 49 of the 58 incidents involve minor surface contamination.

The 72 incidents can be characterized as follows:

• 4 incidents of accidental radioactive material contamination beyond the vehicle

• 4 incidents of accidental radioactive material contamination confined to the vehicle

• 13 incidents of traffic accidents, resulting in no release or contamination

• 49 incidents of accidental surface contamination

• 2 other incidents were mentioned in papers but descriptions are not available.

Eight incidents of radioactive material contamination (between 1960-1984) involved leaks of water, liquid, or (reported as) coolant/moderator from casks which were discovered during shipping. Description of the events and equipment are insufficient to evaluate the failure mechanisms or sources of contamination. However, the abbreviated information provided seems to indicate contributing factors may include the absence of regulations for design and use of transport casks, inadequate procedures, or not following the procedures. Some of the earlier incidents occur-red prior to the establishment of formal transportation regulations (1.966). (See attached incident reports.)

Attached is a table describing each of the 72 incidents in more detail.

Reported Incidents Involving Spent Nuclear Fuel Shipments
1949 to Present (72 incidents by type)

DEFINITIONS FOR RELEASE AND CONTAMINATION AS USED IN TRANSPORT ACCIDENT OR EVENT REPORTS

RELEASE:

An official definition for release from a cask is not found in NRC's 10 CFR 7 1 (i.e., the Definitions section 71.4). However, an NRC definition of release as it pertains to transportation can be inferred from 10 CFR 71 as follows:

[10 CFR 71.4, Definitions] "Containment System means the components of a packaging intended to retain the radioactive material during transport."

[10 CFR 71.5 1, Additional requirements for Type B packages.] Paragraph (a)(1) prohibits loss or dispersal of radioactive contents for Normal Condition of Transport. Paragraph (a)(2) restricts escape of krypton or other radioactive materials for Hypothetical Accident Conditions. Finally, the word release is used in paragraph (b) which states: "Compliance ,with the permitted activity release limits of paragraph (a) of this section must not depend upon filters or upon a mechanical cooling system."

From the above 10 CFR 71 material we can develop a definition that is consistent with NRC's rules and regulations. Release means loss, dispersal, or escape of radioactive material from the package's containment system.

CONTAMINATION:

[10 CFR 71.87(l)(1) and (1)(2), Routine determinations.] refer to . non-fixed (removable) radioactive contamination on external surfaces. These paragraphs prescribe specific limits for transport of radioactive materials. However, a formal definition is not provided.

Although the NRC's regulations do not provide a definition for contamination in 10 CFR 7 1, a definition is provided in NUREG-0770 (U.S. Nuclear Regulatory Commission, Glossary of Terms Nuclear Power and radiation, NUREG-0770,Washington, DC 20555, June 1981). Contamination: "The deposition of unwanted radioactive material on the surface of structures, areas objects, or personnel."