snapshot of the page taken as our search engine crawled the Web.
The web site itself may have changed. You can check the current page or check for previous versions at the Internet Archive. Yahoo! is not affiliated with the authors of this page or responsible for its content.
CONTAMINATION CONTROL WORK PRACTICES handout.d CONTAMINATION CONTROL
WORK PRACTICES





















Fluor Hanford ALARA Center







http://www.hanford.gov/alara/ CONTAMINATION CONTROL WORK PRACTICES

At Hanford, loose radioactive material can be found in plant systems, rooms, ventilation ducts,
fuel pools, and outside radiological work facilities. Work practices used to accomplish
radiological work in nuclear facilities often concern keeping radioactive contamination from
spreading.

This is not an easy task as the contamination activity levels can be very high and the material can
be very unstable. Most of the time, the contamination is not visible, so we have to rely on
surveys taken by Radiological Controls personnel to tell workers where the contamination is
located and the activity levels present.

The work practices used by workers are critical in controlling contamination spread, but it is
impossible to document all of the work practices a worker should use. Many times, something
will happen during the job that could result in a contamination spread. We rely on the workers
knowledge and experience to realize when a potential spread of contamination is occurring, and
take the actions necessary to prevent it from happening. It is important that a worker understand
the concepts of contamination control in order to make the right decisions when work is
accomplished.

In facilities that work with fissile materials there is increased concern that nothing be done that
increases the chance that a criticality accident might occur during work. Criticality safety
personnel need to be consulted and approve contamination control practices that could increase
the potential for a criticality accident.

1. CONFINEMENT (To enclose within bounds, limit, restrict)

Examples of the techniques used to confine the spread of contamination include the use of tape,
sleeving, bags, glovebags, containment tents, catch basins, collection containers, protective
clothing, ventilation, vacuum cleaners, fixatives, aerosol fixatives, polyurea coatings, and
misting with water and other products that prevent the contamination from moving. The
selection of tools used to work on contaminated systems can have a significant effect on whether
contamination is spread.

The following is a list of these products with a brief explanation on how theyre used. Any
experienced worker or RCT that reads this can probably add more examples of products that can
be used to confine contamination spread. So consider this as a living document.
a. Tape: Tape is used to seal plastic bags, cover non-essential surfaces in the work area or on
tools and equipment. It can also be used to decontaminate surfaces.
b. Sleeving: Sleeving is used to cover radioactive material so the contamination isnt spread
during handling. It can be made from transparent, translucent, or solid color materials. The
advantage of using transparent sleeving is that workers can read serial numbers or other data through the sleeving without completely unwrapping the item. The sleeving can be made
from thicker, tougher material than normally found in plastic bags. This reduces the chance
the sleeving will rip or tear if heavy objects or objects that have sharp edges are placed in the
sleeving. It is often necessary to install sleeving over piping joints when hydrotesting
radioactive systems. The sleeving provides spray protection, contains minor leakage, and
this may prevent a spill. Sleeving is sometimes used to cover service lines passing into
Contamination Areas to keep the hose or cable from becoming contaminated. We also
remove a lot of equipment from contaminated systems by raising the piece into a sleeve,
twisting the sleeve, taping, and then cutting through the tape. This is called making an
Umbilical Cut or horsetail.
c. Bags: Bags are similar to sleeving and are used to contain radioactive material. Most
facilities have several sizes of bags to fit the most common items they handle. The bags can
be fabricated to fit unusual shaped pieces and can be padded and contain absorbent. The
bags can have Velcro closures, ties, windows, and pouches for Radioactive Material Control
Tags. Items removed from rooms or containment tents can be bagged in each section of the
tent as its removed to ensure that contamination on the outside of a bag isnt transferred
outside the tent.
d. Glovebags: Glovebags confine contamination at the source. The area that can become
contaminated is limited to the space inside the glovebag. Workers using glovebags may
only have to wear and additional set of gloves instead of donning the protective clothing
usually prescribed for work in a containment tent. Workers who have other work nearby
dont have to wear protective clothing and respiratory protection that might be required if
the job were worked without containment. Guidelines for using containments can be found
in WHC-EP-0749, Radiological Containment Guide.

Glovebags are usually made from flexible 8-mil thick polyurethane or polyvinyl chloride
(PVC). The advantage of polyurethane is that it remains flexible in freezing weather. The
disadvantage is the polyurethane does not glue well so everything needs to be heat sealed to
the glovebag during initial fabrication. The gloves in the glovebag allow personnel to
perform repairs or operate components without directly touching the item. Pass sleeves and
zippered or Velcro openings allow tools and material to be inserted or removed from the
glovebag. The ALARA Center recommends that once everything is placed inside the
glovebag the Velcro or Ziploc seals be covered with a strip of tape on the outside and inside
the glovebag. If contamination levels will be high or aggressive tools will be used, the outer
seal should be a glued strip to make sure nothing escapes. Guidelines for using glovebags
are contained in WHC-EP-0749, Radiological Containment Guide. See Appendix A,
Glovebag Design for assistance in designing a glovebag.
e. Containment Tents: Containment tents enclose the work area and prevent contamination
from spreading outside the tent. Workers have to wear protective clothing to keep
contamination off their skin and clothing when working in the tent. Containments are
obtained from off-site vendors, made at our Site plastic shop, or fabricated by specially
trained workers. Lately, we have been inflating some containments to make them easier to
install. Attachment (B) provides a checklist that can be used to design a containment. Containments can be fitted with liners in the work area to simplify decontamination. When
the floor becomes contaminated, the top liner can be removed and disposed as radioactive
waste. The new liner underneath provides a new uncontaminated floor. Appendix C is a
signoff sheet that can be used to get all parties that will be using a containment tent or
glovebag to approve the design.
f. Catch Containments: Catch containments are installed beneath components or systems to
catch radioactive contamination that might fall or drip. They are usually made from sheet
plastic, but could also be made from metal or hard plastic. Drain connections can be added
at the low point to drain off any liquids. Absorbent can be placed inside the catch
containment if a drain is not installed to collect residual liquids that might drip. Flame-
retardant material could be placed in the catch containment if hot work such as machining,
grinding or welding was being accomplished. If a job is being worked in a glovebag and the
introduction of liquids into the glovebag is part of the job, it might be wise to install a catch
containment under the glovebag. Sometimes there is no room for a catch containment so
drop cloths are laid under the components and workers can stand on the drop cloth to
accomplish the work. Any contamination that falls straight down will be caught on the drop
cloth, just as it would in a catch containment.
g. Collection Containers: The most common collection container for liquids is the Radcon
poly bottle in either the 5 or 15-gallon size. These have an adapter for connecting the hose
that has a fitting for installing a 2-3 CFM HEPA filter. As the plastic bottle fills, the air
thats displaced passes through the HEPA filter. Waste drums can be used as collection
containers when vacuuming contaminated debris. See section 1.j below. Drip pans or
impermeable barriers placed under radioactive collection facilities collect liquids if there is a
spill.
h. Protective Clothing: There are different types of protective clothing that can be worn during
radiological work and Radcon Managers are encouraged to select the type that is appropriate
for the work being accomplished. Launderable protective clothing is available at each
facility. Some facilities are purchasing higher quality b