Clearance is the release from regulatory control of materials
that may contain residual levels of radioactivity. An example
of this is the release of slightly contaminated metal from
nuclear facilities into the general scrap metal supply.
Is EPA currently investigating
the issue of the clearance of metal from nuclear facilities?
EPA began its work on clean materials by examining the
issue of recycling scrap metal from domestic nuclear facilities.
We conducted a technical study to understand both the recycling
process and any potential for the recycled metal to affect
human health. One of the significant findings of this study
was that the amount of metal available for recycle from
nuclear facilities represents only a small fraction (1/1000)
of the steel used in the US annually. Further we discovered
that orphaned sources and imported metals posed a higher
risk. Therefore, EPA suspended its work on a domestic standard,
and the program was redirected to address the orphaned sources
and imports problems.
What are other government
agencies doing concerning clearance?
The NRC is also conducting studies on the clearance of
materials from NRC-licensed facilities and facilities licensed
by states having regulatory agreements with NRC (agreement
states). The results of the EPA studies are available
from this Website, under 'Publications.'
A National Academy of Science panel has completed a draft
study on the clearance of slightly contaminated materials
issue, at the request of NRC.
Is all metal from a nuclear
facility contaminated with radiation?
Facilities operated by the Federal government and private
industry, currently generate scrap metal from routine operations
as well as from facility closure (decommissioning) activities.
Metal from these facilities fall into one of the following
three categories:
Metal that has never been exposed to radiation and can
be recycled just as any other scrap metal;
Metal that has been exposed to some radiation, but can
be cleaned to natural background levels, with its cleanliness
verified before its release to scrap metal dealers; and
Metals that have been exposed to high levels of radiation,
cannot be cleaned, and are not candidates for recycling.
The only appropriate disposition for these metals is isolation
and burial.
What guidelines are currently
used to verify that previously contaminated scrap steel is
clean?
The preparation of contaminated scrap metal from domestic
nuclear facilities for recycling is conducted under guidance
developed by the Nuclear Regulatory Commission and the Department
of Energy in the early 1970s. These guidelines contain "clearance
levels" for individual radionuclides. The clearance levels
were set at the lowest level that could be distinguished
from background by detection equipment, making them 'technology-based
guidelines.' They apply to materials being cleaned that
have only surface contamination, but not to metals that
have been contaminated throughout (volumetrically contaminated
metals).
How much previously
contaminated scrap metal is being recycled from DOE and NRC
facilities?
All of the metal that could potentially be recycled from
DOE and NRC-licensed facilities, including never contaminated
and previously contaminated scrap, represents a very small
fraction (1/1000) of the total steel used in the US annually.
Currently, only small quantities of metal that has been
exposed to some radiation, are cleaned and released from
DOE and NRC-licensed facilities. As many DOE facilities
and NRC-licensed power reactors reach the end of their operating
lives over the next several years, the large quantities
of never contaminated and previously contaminated metal
will be available for recycling, but still represent only
a very small fraction of the total amount of steel used
annually.
What has EPA done so far on
the issue of domestic scrap metal from nuclear facilities?
EPA attempted to answer these questions by conducting
several related studies or analyses:
Identifying the various ways that the recycling of carbon
steel could be handled (called "recycling scenarios")
by talking with managers of DOE facilities, NRC-licensed
commercial power reactors, and firms that provide decommissioning
services, as well as scrap recyclers and steel industry
personnel.
Determining the relationship between residual activity
levels in scrap metal and the potential for industrial
workers or the general public to be exposed;
Studying the economics of scrap metal management by
estimating the amount of scrap metal that may be generated
by these facilities and which of the recycling scenarios
facilities might be followed under various proposed sets
regulations; and
Predicting health effects from the risks posed by scrap
metal management under various sets of economic conditions
and regulations, including disposal.
EPA has prepared two major documents, a Technical Support
Document and a preliminary Cost-Benefit Analysis, as part
of an on-going program to determine the need for radiation
protection standards for scrap metal that may be applied
nationally and internationally.
The Technical Support
Document (TSD) summarizes the technical information
that will be part of the background information used
to help determine whether or not to propose revised
standards for the release of scrap metal. The TSD
provides updated time tables for release of scrap
metals from nuclear facilites, as well as revised
analysis of normalized doses and risks.
The Cost Benefit
Analysis examines the economic ramifications of
the various regulatory options under consideration.
It is important to note that the clearance levels
shown in this document were chosen to ensure that
the analysis covers a wide range of levels and includes
levels that are used in other countries; they should
not be interpreted as EPA recommendations. The decision
on what level to use in any regulation has not been
made.
