Radiation Safety Refresher Training for 2006

Sue Dupre, Radiation Safety OfficerSue Dupre, Radiation Safety Officer

Steve Elwood, Health & Safety SpecialistSteve Elwood, Health & Safety Specialist

Refresher Training Topics

The outcome of the NRC inspection conducted in August 2005

The results of the intensive audits of several labs conducted in 2005 by the Radiation Safety Committee

Some radioactive waste matters

A few contamination episodes

Policy and administrative changes

NRC Inspection Outcome

In August 2005, the University was inspected by an NRCinspector accompanied by NJDEP inspectors. No citationswere issued by the NRC but …

The NRC inspector DID observe beverages in one lab. He chose not to cite us because he believed that it was an isolated incident.

With regard to eating and drinking in rooms designated as radioisotope use areas, be reminded that …..

Eating & Drinking Policyfor Radioisotope Labs

Don’t! It’s Prohibited!

Authorized Users must support lab managers inefforts to control eating and drinking in the lab.

We also continue to find food and beverages in radioisotope cold rooms. Don’t! It’s Prohibited!

NRC Inspection Outcome

The inspector strongly recommended that the Radiation Safety Committee reconsider its security policy with regard to tethering of lockboxes. Previously the Committee had not required that lockboxes be tethered to a secure surface.

As a result the Committee has revised its policy with regard to lockboxes ….

Security & Lockboxes

As a result of the NRC inspection, the RadiationSafety Committee has adopted a new policy forthe use of lockboxes, which allows three options.

Lockboxes must either be:

Stored in a locked refrigerator or freezer or

Stored in a locked room (i.e., the room must be locked when no one is present) or

Tethered to a secure surface

Security & Lockboxes

If EHS staff find a lockbox in an unlocked refrigerator or freezer or in a room that is unlocked and unoccupied, the lab will be required to purchase a tether and to tether the lockbox.

Outcome of Annual RSC Audit

The audit teams found the following problems:

An unlocked padlock on a lockbox – lockboxes must be kept locked

Liquid radioactive wastes were not adequately labeled:

All rad wastes must also be labeled with the isotope and a description of the chemical components of the waste.

A container of radioactive waste that contains hazardous chemical components must be labeled with a yellow haz waste label.

Audit OutcomeIn one lab the common radioisotope workspace set up in ahood was not optimally set up to accommodate all labmembers. Shielding was heavy and cumbersome, andexcess waste materials were stored in the hood, whichlimited the space available for working. It was especiallydifficult for shorter persons to conveniently work withinthe hood.

Reorganize common work areas to make sure that all members of the lab can conveniently work in the area.

Practice good housekeeping and keep the work area well-organized.

Remove wastes promptly to waste pails.

Waste Matters

Project to measure radiation levels for P-32 waste containers

Three years ago, we switched to plastic waste storage pails. There have been concerns that the plastic pails don’t provide the same protection as the old metal pails.

P-32 Waste Pail Survey Project

As a result of these concerns, EHS conducted a waste studythis past year:

Dose rate measurements of P-32 waste pails were made in several labs Measurements were taken on bags of P-32 waste obtained from the

University’s decay in storage facility. Dose rate readings were taken on unshielded bags of P-32 waste.

The bag with the highest dose rate was placed into a new-style plastic pail and then into an old metal pail.

Measurements were taken at the corresponding point of highest reading with the bag in each of the containers.

Waste Pail Study - Results

Dose rate on contact with the pails The dose rate measured on contact with the plastic waste pail was ~

3X higher than the same measurements on the metal pail. As expected, this is due to the greater percentage of betas transmitted through the plastic than the metal.

Dose rate at 1 meter from the pails Dose rate measurements at 1 m were nearly identical, regardless of

container type.

In the plastic pails, more betas are transmitted but fewer bremsstrahlung x-rays are generated in the plastic wall of the pail.

In the metal pails, fewer betas are transmitted but more bremsstrahlung x-rays are generated in the metal walls of the pail.

Remember that the amount of bremsstrahlung x-rays generated as beta particles decelerate depends on the atomic number of the material through which the betas are passing

Waste Pail Study - Conclusion

At distances of 1 meter or more, it does not matter whether the waste pail used to store P-32 wastes is plastic or metal.

We used the highest dose rate measured for any P-32 pail found in our labs to calculate the dose that a researcher would receive if the researcher worked:

1 meter from the pail, 1 hour per day, 365 days per year.

The resultant dose to the lower extremities is ~5 mrem per year

Keep in mind that the extremity dose limit is 50,000 mrem per year

Waste Matters

Good news! It is no longer necessary to remove radioactive material labeling from any items going into radioactive waste, including short-lived P-32, S-35 and I-125 waste.

For long-lived wastes such as H-3, you must keep good records to document the total amount of activity present in a waste container. Waste Can Registers are available from EHS for that purpose

Contamination Episodes

A summer student handling radioactive materials (P-32) forthe first time was not fully supervised during the entireprocedure because he insisted that he could do the rest ofthe work on his own. At one point, he failed to survey hisgloves and did not discover they were contaminated.

During his postoperational survey, he found contaminationin many places. Lab personnel finished the survey andsupervised his clean-up.

Afterwards he told the lab members

“From now on, I’ll do everything you tell me!”

Contamination Episodes

This summer student had completed radiation safety training a week before the incident and had been awake when the subject of contamination control was discussed!

No matter what new users tell you, always closely supervise inexperienced radioisotope users.

Record contamination incidents in the Survey Log!! The NRC inspector questioned why the contamination incident was not recorded in the Log.

Skin Contamination Episodes

1. The student described in the incident on the previous slides had contamination on his forehead.

2. Two researchers in the last three months have found P-32 contamination on their wrists (near where the cuff meets the skin). They were able to wash it off without difficulty.

Lessons Learned The point at which the lab coat cuff meets the skin of the wrist is

a vulnerable area. Always survey that area.

Call EHS immediatelyimmediately (as soon as the contamination is (as soon as the contamination is discovered) discovered) to report skin or clothing contamination. It is not necessary to report contamination on a lab coat unless the contamination is unusually high and could have been present for a significant period.

Lab Coat Laundering & Surveys

P-32 users: it’s easy! Survey the lab coat before turning it in for laundering

For isotopes such as C-14 or S-35, it is more difficult to survey lab coats with a G-M meter because the fabric of the coat may provide enough shielding to prevent contamination from being detected. Should you do a wipe survey of such lab coats or for coats worn during H-3 use?

Consider How much activity has been used while the coat was worn? Was any contamination found during the postoperational survey? What has the past history been for postoperational surveys for this kind of work?

Wipe Surveys of Lab Coats

To survey a lab coat, use a wipe dampened with water and press it several times against locations on the front of the lab coat and on the cuffs. Place the wipe in a vial with liquid scintillation counting fluid and count.  If you see no activity > 100 dpm, go ahead and launder the lab coat.  If you find activity > 100 dpm, call EHS or Mike Fredericks.

Maintenance of Lab Equipment

A microcentrifuge used for H-3 work was taken to the Physics Machine Shop for repair. The Physics staff member removed the side panels of the microcentrifuge and became suspicious because pads located in the interior of the centrifuge were damp.

He requested a survey. Substantial H-3 contamination was found.

A new procedure has been established for the repair and maintenance of any equipment that is potentially contaminated with radioactive materials.

Maintenance of Lab Equipment

1. Be sure to label potentially contaminated equipment with appropriate RAM identification, such as “Caution:  Radioactive Material” tape.

2. Any equipment marked with RAM labeling is “potentially contaminated.”  Such equipment must be surveyed and “released” by EHS prior to maintenance.

3. Contact EHS to perform a survey prior to sending the equipment for maintenance or inviting a service technician into your laboratory.

4. Provide radiation survey documentation (provided by EHS) to anyone who will be working on the equipment.

News at EHS

EHS has hired a new radiation safety technician, Tonya Gruchacz, to replace Mike DuMont who retired

Look for both Tonya and Joan Hutzly as they visit your labs

New Administrative Efforts

Web-Based Dose Reports

Web-Based Dose Reports

Each time a new set of dose reports arrives, EHS will send out an e-mail notice to everyone who is badged

Log in through DBToolbox, using your NetID and LDAP password

Enter your Participant Number

Web-Based Dose Reports

The web dose report will show your dose data for the monitoring periods included in the most recent report and will show your cumulative dose data for the calendar year

EHS will no longer regularly send out paper copies of the dose report to labs but will notify the PI if there are doses of interest or concern

The web dose reports will have more explanatory information than available before (in case you’ve found the old Landauer reports to be confusing to read).

Ordering Radioactive Materials

If you’re ordering materials from the West Coast (MP Biomedicals) or from GE Health Care Life Sciences (formerly Amersham) in Chicago, it’s advisable not to expect your delivery the next day. Most of the time the materials will arrive the next day, but don’t count on it!

If you want to request a replacement order, call EHS first. EHS will contact Purchasing, and Purchasing will call the vendor to arrange for a replacement.

Radioisotope Use

Radioisotope use remained stable in recent years but is experiencing a noticeable decline (20-25% since 2004).

Is this true in your laboratory? How is your work changing? What are the factors driving the move away from radioisotope work?

Can EHS do anything to make radioisotope work more convenient?

Conclusion

Your questions, comments and feedback are welcome.

Contact Sue at 8-6252 or Steve at 8-6271