Fissile material transportation requirements

Criticality in cement waste, up to 68 kg -Flooding of Room 109 -Gross procedural error -Gross rearrangement of fissile material Transportation requirements limit each waste barrel to no more than 350 g of in the cement waste containers. The waste storage area. Room 109, holds up to 180 barrels. 

Packages containing fissile material are required to be designed and transported in such a way that an accidental criticaUty is avoided. Criticality is achieved when the fission chain reactions become self-supported due to the balance between... 

NRC similarly keeps track of all fissile material. Various organizations participate in creating or managing records of packaging, transport, transfer, and disposal of licensed material. In addition, NRC requires records of inspections and tests of materials, facilities for use, or storage, radiation monitoring and other equipment. There are also requirements for security records for the transport, storage, and use of fissile material. NRC requires reports of lost, unaccounted for, or stolen material. 

While still at Princeton, Wigner and Breit applied transport theory to estimate the critical size of a bomb (Paper 2). Similar calculations had already been performed by Peierls and Pryce in England, and by Fermi. Wigner and Breit s calculations confirmed the earlier estimates that an explosive device would require only a few kilograms of fissile material. 

A fission chain is propagated by neutrons. Since a chain reaction depends on the behaviour of neutrons, fissile material is packaged and shipped under requirements designed to maintain subcriticality and, thus, provide criticality safety in transport. In the Regulations the term fissile material is occasionally used to refer both to fissile... 

The requirements for packages containing fissile material are additional requirements imposed to ensure that packages with fissile material contents will remain subcritical under normal and accident conditions of transport AU other relevant requirements of the Regulations must be met. The systan for implonenting criticality control in transport is prescribed in Section V of the Regulations. 

It is possible for accidents to be significantly more severe in the air mode than in the surface mode. In recognition of this, more stringent requirements have been introduced in the 1996 edition of the Regulations for packages designed for the air transport of fissile material. 

Historically, there have always been checks and signatures required for limits and for experiments, while computer codes and calculations have been dealt with on a less formal basis. Part of the reason for this distinction is that the early one-dimensional diffusion or transport codes were not directly applied or applicable to real situations involving fissile material. Plant operations were based on critical or in situ measurements, with a large, conservative safety factor. 

Once they enter the FUJI MSR, fissile materials never leave the site throughout the reactor life. This feature of requiring no fuel transportation for recycling is of great benefit for physical protection because, in general, transport between sites could be a vulnerable point in the nuclear fuel cycle. 

Fissile material meeting one of the provisions (a)-(d) of this paragraph is excepted from the requirement to be transported in packages that comply with paras 673-682 as well as the other requirements of these Regulations that apply to fissile material. Only one type of exception is allowed per consignment ... 

All power-producing reactors require a fissile material, which may be lj233 or Pu, and a coolant to remove the heat from the fuel. In most cases the heat transported by the coolant is used to produce steam to drive a turbine. In this respect the nuclear power plant is similar to a conventional fossil-fueled station, but with the reactor acting as the heat source (see, e.g., Fig. 6.17). 

Packages designed to contain uranium hexafluoride shall meet the requirements prescribed elsewhere in these Regulations which pertain to the radioactive and fissile properties of the material. Except as allowed in para. 632, uranium hexafluoride in quantities of 0.1 kg or more shall also be packaged and transported in accordance with the provisions of the International Organization for Standardization document ISO 7195 Packaging of Uranium Hexafluoride (UF ) for Transport [10], and the requirements of paras 630-631. 

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