Surveillance Program - std301320040054

DOE-STD-3013-2004

relatively high. These failures are generally the result of mistakes made in

manufacturing the product that were not detected during production inspections. In

the case of storage packages described in this Standard, inadequate stabilization

could also contribute to such failures. This is followed by a relatively low failure rate

period, which describes most of the life of the product. Then, as the product reaches

its end of life, the failure rate again climbs to relatively higher values. The relative

magnitude of the three parts of the curve will vary depending on the type of product

and manufacturing process. In light of the lack of long-term storage data on these

plutonium metal and oxide storage packages, it is reasonable to expect that failures

would follow a pattern typified by the bathtub curve. Surveillance Programs should

1) account for the increased failure rate anticipated early in the life of the storage

package; 2) recognize the lower inherent "mid-life" failure rate; and 3) monitor for

the onset of end of life conditions.

There are at least three possible storage configurations that span the risks

associated with plutonium storage. One configuration places the storage package in

a vault that relies on the containment function of the storage package to ensure

public safety. Another places the storage package in a vault that does not rely on the

integrity of the package, and in which the primary risks involve worker safety. A third

possible storage configuration places the storage package in some sort of container

or over-pack. If the over-pack does not rely on the integrity of the storage package,

then the condition of the storage package may not be important to safety, except as

it may affect risks associated with opening the over-pack. The surveillance program

should take into account the risks associated with storage (i.e., the consequences of

failures as well as their probabilities). The program should consider the balance

between these risks and surveillance costs, both in terms of economic impact and

personnel exposure to radiation or other hazardous environments, in determining the

parameters of the surveillance program.

Finally, there are two broad classes of "problems" that surveillance is expected to

detect. The first class could be called "anomalies" because they are single events

that occur more or less randomly in a large population of storage packages. The

second class could be called "systemic" because they affect a significant fraction of

the storage packages, and generally represent an unanticipated condition in those

packages. The surveillance program is expected to be able to distinguish between