IX. Laboratory Monitoring
The safe use of radioactive materials includes periodic monitoring and survey of all areas where significant quantities of radioactive materials are used or stored. Good radioactive material handling practices are evaluated or confirmed by surveys. Contamination of laboratory areas and equipment is a problem of fundamental importance to everyone working with radioactive materials. Constant vigilance to prevent contamination, or to contain its spread, must be maintained by every user. The primary concern in this regard is always the health and safety of the personnel working in the laboratory. In addition, the maintenance of uncontaminated laboratories and equipment is of paramount importance if precise and reliable results are to be obtained.
In order to ensure the safe use of radioactive materials in University laboratories, as required by WAC 246-221-110, monitoring must be conducted by both laboratory and Radiation Safety Office personnel. The authorized users, who constitute the first level of control and responsibility, must perform routine laboratory monitoring to evaluate and ensure their safe use of radioactive materials. The Radiation Safety Office will also perform confirmatory laboratory surveys in all campus locations where radioactive materials are used or stored.
The Radiation Safety Office assigns a laboratory classification for each location in which radioactive materials are used or stored. Those classifications are based upon radionuclide toxicity and frequency of use. (See Table I.) The rationale for the laboratory class selection is based upon the information submitted by the authorized user and reviewed for appropriateness by the RSO. After authorization approval by the RSC, the authorized user is so informed on the Authorization Sheet, with a cover letter detailing the rationale for the RSO determination of laboratory class. In addition, Table II specifies the frequency and type of radiological surveys to be performed by laboratory personnel, as well as by the Radiation Safety Office. When circumstances of radionuclide use in a given laboratory change, within constraints of an existing authorization, so as to alter the laboratory classification, reclassification will be done at the Radiation Safety Office as an administrative matter. That is, the Radiation Safety Office will administratively alter the laboratory classification upon written request by the user after confirmation of appropriateness by the Radiation Safety Office. Any classification may be modified (increased laboratory surveys), as a consequence of problems noted during the RSO's routine audits: RSO reviews which note continued (repeated) items of non-compliance or deficiency, or the staff's professional health physics judgment. Such restrictions are made by the RSO as an administrative matter, with subsequent concurrence of the Radiation Safety Committee. (Laboratory reclassification is not an amendment procedure.)
IX.A. Authorized User Responsibilities
The authorized user and his or her laboratory personnel must monitor the laboratory to ensure that radioactive materials are properly contained after each use. To verify that this monitoring has occurred, required surveys must be recorded. The required frequency for performing and recording surveys is specified on the attachment to the Cover Sheet for an Authorization to Use Radioactive Material. The required frequency and types of user surveys depend on the types and quantities of radioactive material being used, as shown in Tables I and II.
The instructions in this procedure, which apply to methods and techniques for surveying laboratories, reflect the policy and requirements for surveys that must be recorded.
IX.A.1. Survey Methods
Surveys are carried out in order to evaluate fixed and/or removable contamination and radiation fields. Radiation fields and contamination are measured with portable survey instruments. The removable fraction of contamination is measured with wipes that are counted in a liquid scintillation counter or gamma counter, as appropriate, whereas fixed contamination is measured with a portable survey meter. All surveys should be timed to coincide with the completion of radioactive material use procedures. The following discussion of contamination evaluation will be divided into use of swipes or portable survey instruments.
a. Method 1: General Wipe Survey Technique
(1) Wipe Technique: With gloved hands,
(a) Use a Whatman #1 (4.25 cm diameter) filter paper, or similar media, to remove surface contamination.
(b) Wipe approximately 100 cm2 for each survey location, which can be achieved using two fingers and a thumb to hold the Whatman filter and moderate surface pressure to drag the filter about 9" to 1 ft (23 cm - 30 cm).
(c) Count the wipe using routine procedures (such as 1 minute counts, counting vials, etc. ) in the counting system used by your laboratory, using liquid scintillation counter for beta-emitters and gamma well counter for gamma emitters (I-125, Cr-51). A non-contaminated, unused filter should be used as a background wipe for comparison.
(2) Survey Locations: Wipe surveys should be biased toward locations of use (e.g., hoods, bench tops). In addition, a couple of random locations (e.g., refrigerator handles, desks) should be wiped during each survey.
(3) Action Levels:
(a) Wipes in excess of two times background should be recounted to confirm the result. Look for trends in low levels of contamination.
(b) Wipes in excess of 200 counts per minute should be recounted for 5 minutes, and if confirmed, local decontamination efforts should be used.
(c) If widespread contamination is found, call the RSO (5-8916) for assistance.
(4) Records: All wipe results must be recorded on a form which is keyed to a diagram of your lab (see form at this link). /USER%20RADIATION%20SURVEY%20FORM.pdf
(5) Final Step: Always monitor and wash hands after performing wipes.
b. Method 2: Portable Survey Meter Technique
The use of a portable survey meter quickly localizes areas where radioactive contamination or excessive radiation fields exist. If a meter survey indicates contamination on a work surface, take a wipe.
(1) Prior to surveying, check the battery's status, determine the instrument's background (known low background areas can be the hallway), and check the instrument's response to a source of radiation (e.g., check source, stock vial).
(2) Move the survey meter probe over surfaces slowly enough to compensate for any erratic meter movement. (Meter probe should not be allowed to come in contact with the surface.)
(3) Survey areas of use and storage (including the waste box).
(4) Action levels - Investigate any anomalous levels of radiation. Consult with RSO (5-8916) for assistance. Certain locations would be expected to have readings above background, e.g., waste containers, stock solutions.
(5) Records - Record all results on a map which is keyed to the survey locations (see the following link for the prescribed form). /USER%20RADIATION%20SURVEY%20FORM.pdf
IX.A.2. Survey Frequency and Multi-User Facilities
a. Survey Frequency
The frequency of surveys depends on the type and quantity of radionuclides used in the laboratory. When a laboratory is authorized for radioactive material use, the laboratory rating is assigned based on the radionuclides used and the average amount used in one month. There are six laboratory classes: A, B, C, D, E, and S. A is a minimal hazard laboratory, and D is the highest hazard laboratory. S is reserved for special use laboratories. Locations which have very infrequent or special use may be assigned Class "S" to allow greater flexibility in the RSO's oversight authority. For example, all training classes using radioactive materials will be assigned laboratory class "S," as will locations where in the judgment of the RSO, prior notification is prudent and appropriate. The "S" lab classification requires that the authorized user contact the RSO prior to working with the radioactive material. Laboratory ratings are determined by the Radiation Safety Office using Tables I and II as a guide.
The survey frequency for the authorized user and for the Radiation Safety Office depend on the laboratory rating. Table II summarizes the frequency and type of surveys required by the user for the various lab ratings and radionuclides.
Please note: In laboratories rated A, if a portable instrument is not routinely available and used during routine work, weekly wipe surveys must be performed instead of monthly instrument surveys.
When no radioactive material has been used or stored since the last survey, no survey is necessary, but the reason for skipping the survey must be noted in the survey records. If material has not been used but is being stored, surveys must still be done but at a lower frequency. For storage only, A rated laboratories must be surveyed at least quarterly and B, C, and D labs must be surveyed at least monthly. The reasons for this reduced survey frequency should be noted on the survey form.
b. Multi-User Facilities
In the case where more than one authorized group uses a laboratory, the responsibility for conducting surveys will be assigned by the cognizant Dean, Chairman, or Director to a single authorized user in that unit. The Radiation Safety Office will be apprised of the identity of that responsible party by memorandum.
IX.A.3. Where to Survey
Surveys should be conducted in all areas where radioactive material is used or stored. Areas where contamination is more likely should be surveyed with greater attention. Some areas of particular importance are listed below:
a. Floor near storage of radioactive material, including waste;
b. Floor in front of hoods and work benches;
c. Hood lip and sash;
d. Areas on work bench where work is done;
e. Floor near exit from lab;
g. Interiors of storage areas;
h. Handles on refrigerators and freezers where radioactive material is stored;
i. Other miscellaneous items that could be contaminated: e.g., telephones, doorknobs, instrument dials.
IX.A.4. How to Record Surveys
All required surveys must be recorded. At this link, /USER%20RADIATION%20SURVEY%20FORM.pdf , is a standard form suggested for use. This form is very similar to the form that Radiation Safety Office staff use to survey laboratories. Use of this form will remind the user of action levels for contamination and proper safety practices in the lab. If this form is used, copies should be made from the original. If another form is used, the following information should be recorded:
a. Room and building surveyed;
b Name of surveyor;
c. Date of survey;
d. Diagram or map showing facilities surveyed;
e. Instrument used to perform survey;
f. Results of background count;
g. Results of wipe tests and portable instrument surveys;
h. Actions taken for any contaminated areas or items;
i. Reason for missed surveys or decreased survey frequency.
In laboratories where the locations surveyed and the instruments used are always the same, this information can be typed onto the standard form.
As noted under the section on survey frequency, when no radioactive material has been used or stored in a lab since the last survey, no survey needs to be done. However, a dated record must be established stating that no survey was done because no radioactive material was used. This record can be added as a note to the most recent required survey.
IX.A.5. General Laboratory Practices
When performing required laboratory surveys, it is a good practice to be alert for unsafe laboratory practices or conditions in the lab that could lead to the loss of radioactive material or to uncontrolled contamination. Some conditions that should be noted and corrected are
a. Laboratory Housekeeping
If laboratories are messy and housekeeping is especially poor, these conditions could contribute to the uncontrolled release of radioactive material.
b. Food and Drink
(1) The consumption of food and beverages in radioactive material laboratories at the University is strictly prohibited. The presence of empty food and drink containers will constitute a violation of regulations, since it will be inferred that consumption occurred on the premises.
(2) Food or drink must not be stored in refrigerators or cold rooms that contain radioactive materials.
(3) Food or drink preparation should not occur adjacent to radioactive material usage areas.
(4) Food and drink may be transported (expeditiously) through a radioactive materials laboratory only if in a completely closed container.
(5) Laboratory glassware and other equipment should not be used for food or drink.
(6) Food or drink containers should not be used for laboratory materials, unless conspicuous new markings are present to indicate the new use as a laboratory container. (Food and drink materials which are being used for a legitimate experiment constitute an obvious exception; proper labeling of containers will explain the purpose to inspectors.)
c. Radioactive Waste
(1) Radioactive waste should not be placed in the hallways or other unrestricted or unsecured locations.
(2) Radioactive waste receptacles should be identified with the proper warning labels, tape, or stickers.
(3) Radioactive waste must not be mixed with normal trash or placed in ordinary waste baskets.
d. Laboratory Security
Radioactive material laboratories must not be left open and unattended while radioactive material is accessible.
IX.A.6. Inspection of Records
Survey records will be inspected by Radiation Safety Office staff. If survey records are found not to be complete and correct, a verbal warning will be issued on the first such occasion. Thereafter, letters will be sent to the authorized user to register noncompliance situations.
IX.B. Radiation Safety Office Responsibilities
The Radiation Safety Office is responsible for ensuring that all required laboratory surveys are performed by the authorized user and laboratory personnel, and for conducting periodic surveys for further verification of compliance. Moreover, the Radiation Safety Office conducts all required sealed source leak tests. Finally, the Radiation Safety Office is responsible for ensuring timely calibration of all laboratory survey instruments.
IX.B.2. Laboratory Surveys
Laboratory surveys are conducted in accordance with the schedule set forth in Table II above. Laboratory classification will change according to changes in use, as determined during interactive dialogue between the cognizant authorized user and the Radiation Safety Office. Records of these surveys are retained in the Radiation Safety Office. In the event of an instance of non-compliance, notice is given to the cognizant authorized user.
a. Delinquent Survey Log Book
When a laboratory survey log book is found to be delinquent, a verbal warning is issued for the first such event. Thereafter, a letter of notice of non-compliance is sent to the authorized user. When the third such letter is issued within a twelve-month period, the Radiation Safety Committee is notified so that it may take appropriate action.
b. Laboratory Contamination
If contamination below the threshold of 500 cpm for a wipe test is discovered, a verbal notice is given to the authorized user or to cognizant laboratory personnel. If contamination above this threshold is found, a letter of notice of non-compliance is issued to the authorized user. When the third such letter is issued within a twelve-month period, the Radiation Safety Committee is notified so that it may take appropriate action.
c. Food or Drink in Laboratory
When evidence of food or drink is found in a radioactive materials laboratory, a letter of notice of non-compliance is sent to the authorized user. When the third such letter is issued within a twelve-month period, the Radiation Safety Committee is notified so that it may take appropriate action.
d. Other Cases
When other cases of non-compliance are observed, such as a messy laboratory, failure to post a Notice to Employees or Emergency Information, improper waste storage, use in an unauthorized location, or other unauthorized use, notice is given to the authorized user or laboratory personnel. This notice may be verbal or written, depending on the severity of the breach of regulations. Multiple such occurrences may be reported to the Radiation Safety Committee by the Director, Radiation Safety Office.
IX.B.3. Sealed Source Leak Tests
Each sealed radioactive source, other than hydrogen-3 (tritium), with a half-life greater than 30 days and in any form other than gas, will be tested for leakage by means of a swipe test prior to initial use and at six-month intervals in accordance with the requirements of WAC 246-221-080. The leak tests, to be performed by a member of the Radiation Safety Office staff, will be capable of detecting the presence of 0.005 microcuries (185 Bq) of removable contamination. The results of all leak tests will be recorded in an appropriate record system in units of microcuries or becquerels. Leak tests are required for sealed beta or gamma sources with an activity of 100 microcuries (3.7MBq) or greater, and for alpha sources with an activity greater than 10 microcuries (370 kBq).
If a sealed source shows evidence of leaking, the source will be immediately withdrawn from use, decontaminated, and repaired or disposed of as appropriate. In the event of the detection of a leaky sealed source, a report will be filed with the State of Washington Department of Health, Radiation Control Section, within five days of the test, describing the source, the test results, and the corrective action taken.
sealed sources not being used may, however, be placed in an appropriate sealed
container and placed in long-term storage in the cave room of the
IX.B.4. Survey Meter Calibration
Survey instruments are to be calibrated annually, or following any maintenance, excluding battery replacement. The Radiation Safety Office (RSO) will calibrate survey instruments free of charge upon request and if the RSO is capable of doing so. In such cases, the authorized user (AU) must furnish the RSO with a copy of the instruction manual.
If the authorized user chooses, or the RSO is not equipped to calibrate an instrument, the calibration must be completed by a qualified service provider at the AU's expense. Once completed, the AU must provide the RSO with a copy of the calibration certification in a timely manner. The calibration frequency/interval for all survey instruments must be maintained, documented, and records retained by the RSO.
If work with radioactive materials is to continue while an instrument is being calibrated or repaired, the authorized user may obtain a temporary loaner instrument from the RSO.