Residues - std301320000025

DOE-STD-3013-2000

storage is underpinned by extensive experience with plutonium-uranium mixed oxide (MOX)

fuel in the commercial nuclear power sector.

Acceptability of materials at the Y-12 Plant is determined in accordance with the Y-12

acceptance criteria [USDOE 1997]. In very broad terms, the upper limit for plutonium is set at

5 ppm. This limit has been accepted as the lower limit for plutonium in uranium to be

dispositioned by the Materials Disposition Program [USDOE 1998].

The minimum plutonium

"RESIDUES"

content for those oxides

The word "residue" does not have a concise, consistent definition

that have significant

from site to site. During the time that weapons were being

produced, there were three general categories of plutonium:

quantities of uranium has

1) product metal or oxide or fuels-grade metal and ceramics;

2) residues - materials that were recycled to recover the

been set at the safeguards

plutonium; and 3) very lean material designated as waste, which

termination limit. This

was discarded. The distinction between residues and waste was

largely economic. When processing was stopped, some product,

provides a convenient and

residues, and wastes were left in unsatisfactory storage

conditions [see e.g., DOE 1994c, DNFSB 1994]. This led to DNFSB

practical threshold for

Recommendation 94-1 and the DOE 94-1 Implementation Plan

distinguishing between

(IP), which defined categories for all materials. Categorization

was worked out on technical and practical grounds, with oxides

materials that require

and metals >50 wt% Pu comprising one category, and residues

and mixed oxides <50 wt% a second. However, the Rocky Flats

continued safeguarding (or,

"Residues EIS" codifies five residue categories, none of which

alternatively, further

include oxides. Rocky Flats plans to place its oxides in long-term

storage, as it is commonly understood that the Fissile Materials

processing to reduce the

Disposition Program will accept all RFETS materials currently

attractiveness prior to

categorized as oxides. Thus, at Rocky Flats, and generally

throughout the complex, the word residue has come to mean

disposition), and those that

materials to be discarded, not stored long-term.

might be disposable

Most Rocky Flats residues have been declared waste and are

destined for appropriate low-level or TRU disposal, although a

without further processing,

very small fraction may be processed. Some residues at other

regardless of the

sites may also be processed to produce a storable oxide or metal

based on practical, programmatic considerations. Since the

enrichment level of the

products of such processing are expected to have impurities and

other characteristics similar to the materials already categorized

contained uranium.

as oxides or metals, they are included in the scope of this

Standard.

This Standard does not

In summary, oxides are included in the scope of the Standard

apply to materials destined

and residues are not. Broadly speaking, oxides in the EM program

are destined for disposition by the Fissile Materials Disposition

for WIPP, such as residues

Program and residues are destined for disposal. Finally,

plutonium content is not the distinguishing factor between oxides

and TRU Waste.

and residues the two are separated in the final analysis by

programmatic decisions.

The scope of DOE-STD-

238

3013-96 limits the