Interpretation

DOE-STD-1027-92

ATTACHMENT 1

INTERPRETATION: Facilities with the potential for nuclear criticality events or with

sufficient quantities of hazardous material and energy, which would

require on-site emergency planning activities.

CRITERIA:

The criterion is that given in 10 CFR 30, with rebaselined calculation.

This criterion is essentially possession of quantities of material whose

unmitigated release could produce total doses of 1 rem in the range

of 100 meters from the facility.

In addition, any facility containing fissile material in quantities greater

than the theoretical minimum mass limits for criticality emergencies

as specified in ANSI/ANS-8.1-1983, R88 "Nuclear Criticality Safety in

Operations with Fissionable Materials Outside Reactors" should be

included. For aqueous solutions of U 233, U 235, and Pu 239, these values

are 500, 700, and 450 grams, respectively. Credit may be taken if

segmentation or nature of process precludes potential for criticality.

CONSIDERATIONS: The intent of this threshold is to capture those quantities of material

whose unmitigated release would require an emergency plan for on-

site evacuation. The NRC has specified certain values in 10 CFR 30

with a defined threshold of a 1 rem dose at 100 meters. DOE has

evaluated these numbers and made certain modifications to release

fractions which are explicitly allowed in the regulation. DOE has also

modified the meteorology used in the threshold calculation.

Specific groundrules for Category 2 hazard categorization are as follows:

In general, it is necessary to consult the individual threshold values

only if an individual isotope is being isolated and collected for some

purpose. For example, if a facility processes weapons grade

plutonium, it can simply be classified on the aggregate amount of

Pu239 present without specifying quantities of trace isotopes (i.e.,

Pu238, Pu240, Am241, etc.) carried along in the mixture. Likewise, if a

fuel reprocessing plant has more than 1000 curies of mixed fission

products, it is a Category 2 facility with no need to consider individual

radionuclide make-up.

Facilities are considered Category 2 if the potential for criticality exists

in the storage arrays and processing means used.

Hazard Category 3

Hazard Analysis shows the potential for significant but localized

DEFINITION:

consequences.

A-3