University of Pennsylvania
Radiation Safety Office

Tandem User's Guide

Outline

A. Personnel Dosimeter Policy
B. Dosimeter Placement
C. Dose Reports

A. Wear lab coats, gloves or other protective clothing when there is a possibility for external contamination.

B. Do not eat, drink, or smoke in the target room or areas where the possibility for airborne effluent exists.

C. Careful experimental planning, dry runs, shielding, distance, and monitoring are required for minimizing exposure.

D. The facility must be secured at all the times against unauthorized entrance.

E. Keep a record of quarterly sealed source inventory.

F. Radioactive waste disposal and procedures

1. Collect contaminated protective clothing and articles in appropriate containers as radioactive wastes.

2. Identify the radionuclides that make up the waste.

3. Monitor the exposure rate from radioactive wastes storage monthly or whenever new wastes added.

4. Store wastes being stored for decay (T1/2 < 65 days) for a minimum of 10 half-lives, and ensure that the exposure rate from the unshielded surface of the container is no greater than background prior to disposal. Keep a log of wastes being stored for decay shall be kept.

G. Use approved fume hoods or glove boxes to control possible airborne contamination.

H. Label the facility with proper radiation signs.

I. Wash hands thoroughly after working at contaminated area.

J. All personnel working in the facility must have radiation safety training prior to working, and annually thereafter.

K. Keep a daily operations log book. Record all operation parameters in this book.

L. Notify the Radiation Safety Office (RSO) promptly in the event of:

1. Personnel contamination

2. Any accident resulting in direct exposure to personnel

3. Unexpected loss of Radioactive Material (RAM) to air or sewer

4. Loss of RAM

A. Personnel Dosimeter Policy

All personnel working at the facility are required to wear one of the radiation monitoring devices provided by the RSO. These devices are:

i. A film Badge to monitor doses to the whole body
ii. A TLD dosimeter to monitor doses to the whole body
iii. A pocket dosimeter to indicate the accumulated exposure.

B. Dosimeter Placement

Interpretation of the measured dose is dependent upon the placement of the dosimeter. It is important that all personnel wear their dosimeters correctly. All dosimeters must be worn on top of lab coat close to the collar.

C. Dose Reports

The Radiation Safety Office sends dose summary reports on a monthly and an annual basis. These reports should be posted in a conspicuous location in the facility.

A. Do not enter the high radiation area while the accelerator is operating.

B. Check extremities with a survey instrument for possible contamination whenever the beam line has been opened.

A. Check the exposure reading before entering the area.

B. Ensure that the exposure is less than 5 mR/h before entering the area.

C. Wear a neutron dosimeter.

D. If the primary exposure survey indicates the exposure is larger than 5 mR/h, leave the area and acquire approval from the Radiation Safety Office before performing the maintenance.

E. Wear a lab coat or protective clothing during the maintenance procedure.

F. Carry an audible monitoring device.

G. If the maintenance work requires opening the beam line, wear gloves and protective clothing and check extremities for possible contamination before leaving the area.

H. Survey any part of beam line that has been dismantled with a survey instrument before further handling.

J. Maintenance on the contaminated parts

1. If maintenance procedure calls for sanding or milling of the contaminated parts, survey the residues.

2. If the survey indicates any contamination, collect the residues in a bag and treat them as radioactive waste.

3. Identify the activity and isotope and note them on the bag.

4. Survey the work area.

5. Check your extremities for possible contamination before leaving the work area.

A. Ensure that the exposure is less than 100 mR/h before entering the radiation area.

B. Notify the Radiation Safety Office.

C. Follow all the instructions given in part IV.

D. Do not enter the area with exposure larger than 100 mR/h without the presence of a representative of the RSO.

A. The safety interlock must be fail-safe; that is, it must be designed so that a defect or component failure in the interlock system prevents operation of the accelerator.

B. Entrances to vault and target areas must have a double-interlock system.

C. The operation of safety interlock systems must be checked quarterly and the results recorded in a log book.

D. The interlock trip system must be checked to insure that the accelerator will resume operation only after the controls have been manually reset at interlock positions and finally at the main control console.

E. Check the functionality of scram buttons or other emergency power cutoff switches located in high radiation areas. This must include checking the cutoff switch, the manual reset, and the inability to restart the accelerator from the control console with resetting the cutoff switch.

F. An easily visible warning light must be installed to warn the staff when the interlock system is by-passed.

G. The safety interlock system by-pass must be recorded in the daily operational log book.

H. The vault area must be equipped with lights and an enable switch. The Faraday cup will not retreat unless the light inside vault is turned off, the enable switch is activated, door to the vault is closed, and by pass key is removed. There must not be any switch at the accelerator control console to make the Faraday cup retreat.

I. A member of the staff must check inside the vault to assure that area is cleared of personnel before putting the Faraday cup in retreat position.

J. The area must be equipped with devices that will automatically activate visible and audible alarms to alert personnel in the vault area to operation of the accelerator. The system must allow sufficient time for an individual in the area to operate a clearly identified control device which must be present in the area and which can prevent the initiation of irradiation.

K. At no time shall staff enter the high radiation area with exposure larger than 100 mR/h without a representative of the RSO.

A. Bypass the interlock only for the purpose of stabilizing the beam.

B. Obtain the key for bypass from the operator.

C. In bypass mode, an alarm will sound when anyone enters the vault area. The alarm will be heard at the control console.

D. Carry an audible monitoring device.

E. In bypass mode, if the exposure is larger than 5 mR/h, put the interlock into operation and notify the RSO.

A. Exposure Survey

1. Check radiation exposures at the facility during the operation of accelerator quarterly or whenever a new procedure is in process.

2. Ensure that Laboratory and vault areas have permanent exposure monitors which sound an alarm at 5 mR/h trigger levels.

3. Record quarterly exposure checks.

B. Perform leak testing of sealed sources semi-annually.

Calibrate all survey instruments annually or following a repair. Check all instruments for proper response to radiation before each use.