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Chapter 5 - Policies & Procedures
 
5.0 Policies and Procedures for Radiation Use Areas (Top)
 
 

5.1.1 Areas shall be defined with regard to radioactive material and radiation fields under the following classifications.
 
Table 5.1 Area Access Restrictions.
The following terms are used in the Radiation Safety Manual, permits and operating procedures for the purpose of regulating which personnel may enter an area. 
Area​ Definition ​
Uncontrolled Area* (Unrestricted Area)+ An area where access is neither controlled nor restricted ​
Secure Area​ An area where access is limited to specific personnel as a condition of either a radioactive material or RPE use permit 
Controlled Area* (Restricted Area)+​ An area where access is restricted to authorized radiation users and accompanied visitors 
Exclusion Area​ An area where access is prohibited while a sealed source or RPE is in use  ​
     
 *New York State Sanitary Code Chapter 1 - Part 16
+ U.S. N.R.C. 10 CFR 20 
 
Table 5.2 Area Use Restrictions. 
The following terms are used in the Radiation Safety Manual, permits and operating procedures for the purpose of regulating where radioactive material and RPE can be used. 
Area​ Definition​
Authorized Radiation Use Room​ A room authorized for use and/or possession of radioactive material or RPE 
Area Labeled for Radiation Use  ​ An area within an authorized radiation use room which is designated a controlled area, including sites where radioactive material is handled (such as bench tops), stocks and waste are stored, hoods, equipment, etc. or where RPE is used 
Non-Radiation Use Area​ A non-labeled area within an authorized radiation use room where radioactive materials are not used, such as desks and other work benches 

Table 5.3 Radiation Field Warning Classifications. 
The following terms are used in the Radiation Safety Manual, permits and operating procedures for the purpose of warning individuals as to the intensity of radiation fields in the area.
Area Definition​
Radiation Area​ An area where an individual located 30 centimeters from any source of radiation could receive greater than 5 mrem in one hour 
High Radiation Area​ An area where an individual located 30 centimeters from any source of radiation could receive greater than 100 mrem in one hour 
  Very High Radiation Area​ An area where an individual located 100 centimeters from any source of radiation could receive greater than 500,000 mrem in one hour  ​

    
5.1.2 External dose rate limits from radiation fields for each of the areas defined in section 5.1.1 are the following: 
 
Table 5.4  External Dose Rate Limits from Radiation Fields
Area​ External Dose Rate Limit (mrem/h)​  CU ALARA Guideline (mrem/h)​
Inside Controlled Area or
Area Labeled for Radiation Use​
limited by dose received by user,
not dose rate alone​
limited by dose received by user, not dose rate alone​
Uncontrolled Area,
outside of Secure Area
 or Non-Radiation Use Area
 or Exclusion Area (while occupied)​
2.0 at the perimeter of controlled and labeled areas and 0.05 at or beyond 30 cm from the
perimeter of controlled and labeled areas*​
 0.5 at the perimeter of controlled and labeled areas and 0.05 at or beyond 30 cm from the perimeter of controlled and labeled areas*​
*At a constant dose of <0.05 mrem/h the 100 mrem/yr. is achieved.
5.1.2.1 Dose rates shall be kept ALARA. In most cases, external dose rates at or below the CU ALARA Guideline are achievable.  
5.1.2.2 Dose rates may exceed the above limits with prior authorization from the RSO.
5.1.3    Contamination shall be kept below the following limits for each of the areas defined in section 5.1.1. 
 
Table 5.5 Removable Contamination Limits   
Area  Removable Contamination Limit (dpm/100 cm2) CU ALARA Guideline (dpm/100 cm2)  
Inside Controlled Area or
Area Labeled for Radiation Use
500 for α emitters
5000 for β and or γ emitters
100 for α emitters
1000 for β and or γ emitters
Uncontrolled Area,
Outside of Secure Area,
Exclusion Area
 or Non-Radiation Use Area
100 for α emitters
1000 for β and or γ emitters
100
Personnel
(skin, hair, personal clothing)​
not detectable​ ​ not detectable ​​
Table 5.6 External Dose Rate Limits from Fixed (non-removable) Contamination
Area​ Dose Rate Limit
mrem/h at 1 cm)​
CU ALARA Guideline
(mrem/h at 1 cm)
Inside Controlled Area or
Area Labeled for Radiation Use
1​ 0.5​
Inside Uncontrolled Area,
outside of Secure Area,
Exclusion Area, or
Non-Radiation Use Area
0.2​ 0.05​
Personnel
(skin, hair, personal clothing)
0.1​
not detectable 
 
 

5.1.3.1    Contamination shall be kept ALARA.  In most cases, contamination levels at or below the CU ALARA Guideline are achievable. 

5.1.3.2    If any individual’s skin, hair or personal clothing is found to be contaminated above background readings, immediately contact Cornell Police by calling 911. (See Chapter 10, section 10.2.2.7)
5.1.3.3    The permissible levels on glassware, tongs, lead bricks, and other laboratory equipment will be the same as those for working surfaces; however, it is expected that, in certain instances in which such equipment is to be used over again in radiological operations, contaminated equipment will be present and is permissible as long as it is appropriately labeled and stored separately from uncontaminated equipment. The glassware will be labeled as being radiologically contaminated and must be kept within an area labeled for radiation use.   
5.1.3.4    To ensure that these levels are maintained, the permit holder will perform and record routine surveys of all areas under his control.  
5.1.3.5     In general, no radioactive contamination can be tolerated. Exceptions to this will include certain hood trays, stainless steel trays, Kimpak covered surfaces, or other equipment which is used frequently for active work and which will be clearly marked with the standard radiation caution signs or stickers. 
 

5.2.1    A “RADIOACTIVE MATERIALS USED IN THIS FACILITY” sign shall be conspicuously posted at each entrance    to laboratories where radioactive materials are stored and/or are used. 

 
5.2.2    Radioactive use and storage areas and equipment shall be conspicuously marked with a “CAUTION, RADIOACTIVE MATERIALS” sign. The perimeters of areas labeled for radiation use shall be conspicuously marked. In addition, containers in which materials are transported or stored shall bear a durable, clearly visible label bearing the radiation caution symbol and the words “CAUTION, RADIOACTIVE MATERIALS”. This label shall also state the quantities and kinds of radioactive materials in the containers and the date of measurement of the quantity. 
 
5.2.3      Radiation areas, high radiation areas and very high radiation areas, as defined in Table 5.3 of this section, shall be posted with the sign “CAUTION, RADIATION AREA”, “CAUTION, HIGH RADIATION AREA”, and “GRAVE DANGER, VERY HIGH RADIATION AREA”, respectively.  
 
5.2.4    All equipment contaminated with radioactive material shall be marked with signs, decals, or other conspicuous means. Labeling shall not be required for laboratory containers such as beakers, flasks, and test tubes, used in transiently in laboratory procedures during the presence of the user.   
 
5.2.5     Prior to removal or disposal of an empty container, including shipping boxes, confirm that it is free of contamination and remove or deface any radioactive material label and other markings referencing radioactive materials.

EH&S will check during periodic surveys to ensure that adequate shielding is used in all radiological operations. The total amount of shielding materials that will be necessary will depend on the amount of activity and the type of radiation involved. In some instances, it may be necessary to construct a "hot cell" or large shielding barrier to meet shielding requirements.  EH&S will be available for consultation on all shielding problems encountered. 

 

5.4 Aerosols, Dusts and Gaseous Products (Top)

5.4.1     Procedures involving aerosols, dusts or gaseous products or procedures which might produce airborne contamination in excess of regulatory limits shall be conducted in a hood, dry box or other suitable closed system.  These procedures must be authorized in advance. 

5.4.2     All release from such systems shall not exceed ten percent of the maximum permissible concentration in air for nuclide in question, unless regulated by a DEC Part 380 permit. However, where practical, traps should be incorporated in the experimental set-up to ensure that environmental releases are as low as possible. 

5.4.3     Radioactive gases must be stored in gas-tight containers and must be kept in areas having approved ventilation. 

5.4.4     Hoods to be used for radioisotope work shall be tested by EH&S to ensure that they meet the minimum requirements for air velocity at the face of the hood. 

5.5 Work Surfaces (Top)

All areas where radioactive material is used or stored shall be covered at all times with plastic-backed absorbent paper (e.g. “Kimpak”), stainless steel or plastic trays, uncracked glass plates or other impervious material. Absorbent paper should be replaced when damaged. 

5.6 Periodic Surveys of Radiation Areas (Top)

Areas (e.g., hoods, bench tops) in which radioactive materials are being used should be checked for contamination as soon as each procedure is completed by the radiation workers in that laboratory.  These areas shall be inspected each and every time there is reason to suspect a contamination; these surveys do not have to be recorded but action (i.e. decontamination) is required if limits are exceeded.  Monthly wipe and instrument surveys shall be conducted with recorded positive and negative survey results in the Permit Holders’ laboratory logs. 

5.7 Laboratory Monitors (Top)

Each laboratory or area (other than those where only H-3 is used) shall be equipped with a calibrated, functioning portable or semi-portable survey instrument to be used for personnel and area monitoring.

5.8 Removal of Equipment from the Laboratory   (Top)

Once used for radioactive substances, equipment shall not be used for other work or sent from the  area  to  cleaning  facilities,  repair  shops,  or  returned  to  the  source  of  supply,  until a meter and wipe survey have been completed and contamination levels are under 100 dpm/100cm2.   The survey shall be recorded and record kept with other lab survey records.  A "Terminal Survey Notice" from EH&S Radiation Safety, stating that the equipment has been demonstrated to be free of contamination shall accompany the equipment.

 

5.9 Maintenance of Laboratories and Equipment (Top)

Laboratories or equipment to be serviced in the lab by shop, maintenance or custodial personnel, or by commercial contractors, shall be demonstrated (METER AND/OR WIPES) to be free of contamination (i.e. less than 100 dpm/100cm2 prior to servicing.  The survey shall be recorded and record kept with other lab survey records.  If necessity requires that emergency repairs be performed in contaminated areas, or on contaminated equipment, the work will be supervised by a member of EH&S staff, who will assure that the necessary safeguards are taken.  Laboratory personnel are responsible for requesting this supervision from EH&S.  

Prior to facility repair or maintenance (e.g. floor refinishing, leak repairs, etc.), the lab shall perform and record a meter and wipe survey of the affected area(s). 

5.10 House Vacuum Lines (Top)

 

House vacuum lines are vulnerable to contamination. If house vacuum lines are to be used, the withdrawn gas must be free of radioactivity. Use a separate vacuum system whenever possible, such a separate vacuum pump exhausting into a hood.
 

 

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