Washington State University
SAFETY POLICIES AND PROCEDURES MANUAL

RADIATION SAFETY
9.42
Revised 3-02
Radiation Safety Office
335-8916

Laboratory Survey Program

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RESPONSIBILITY

Authorized users are responsible for periodically surveying all areas where radioactive materials are used and stored. Authorized users must conduct these surveys with appropriate instruments and methods.

The RSO recommends that authorized users perform surveys after each day's use of radioactivity. However, authorized users must record surveys for inspection by the Radiation Safety Office at a frequency required to assure compliance with applicable regulations.

FREQUENCY

Laboratory Classification

The Radiation Safety Office classifies laboratories in accordance with the monthly level of use of radioactivity of four hazard groups of isotopes. See the laboratory classification table in the PDF version of 9.42.2.

Weekly Surveys

Laboratory Classes B, C, and D require documentation of weekly surveys.

Complete a Laboratory Survey form for each weekly survey. Obtain the form from the RSO or print the PDF master on 9.42.8 or complete onscreen and print to make copies as needed.

Monthly Surveys

Laboratory Class A requires documentation of monthly surveys.

Complete a Laboratory Survey form for each monthly survey. Print the PDF master on 9.42.8 or complete onscreen and print to make copies as needed.

Special

Laboratory Class S is a special laboratory designation which allows the authorized user to maintain a laboratory for future radioactive material (RAM) use. No surveys or postings are required because no RAM is stored or used in these laboratories.

REQUIREMENTS

Surveys must include all areas of radioactive material use (e.g., fume hoods, work benches, floor around work areas, storage areas, door handles). In addition, radiation surveys should include selected areas where radioactive contamination is neither likely nor expected.

Radiation surveys are employed to detect both fixed and removable radioactive contamination.

Methods

The surveys must be done using wipe methods and portable survey instruments. (Wipe methods alone are sufficient for laboratories using only 3H.)

Each laboratory (except those using only 3H) must possess an appropriate portable survey instrument.

WIPE SAMPLING

Wipe (swipe or smear) sampling is a radiation survey technique used to evaluate removable contamination from articles, surfaces, and personnel.

Using a gloved hand, personnel hold a Whatman #1 filter (or equivalent sized and shaped material) between the thumb and index finger plus middle finger. To wipe (swipe or smear) a surface, the filter paper is pressed firmly and uniform pressure is applied over the area being sampled.

Approximately 100 square centimeters (cm2) is the standard area sampled during a wipe. Make a one-foot-long S-shaped motion with the wipe to approximate an area of 100 cm2. (The use of the 100 cm2 standard permits ready comparisons among sampling points).

Survey Logbook

Each laboratory must maintain a radiation survey logbook. This logbook contains records of laboratory surveys performed for each location of use or storage.

Each survey report must include the following information:

The map must identify relevant features such as stock and sample storage areas, waste storage areas, work areas, refrigerators, sinks and hoods. Include selected areas which are not expected to be contaminated, e.g., telephone, chairs, desks.

Contamination

If a sample shows contamination, the location must be decontaminated.

Following decontamination, perform a follow-up wipe survey of the location for removable contamination. Enter the follow-up survey results and a description of corrective actions in the survey logbook. Record any appropriate meter surveys.

Schedule

The authorized user must perform the required laboratory surveys and enter the results into the logbook according to the schedule dictated for that laboratory and classification. See the survey requirements schedule in the PDF version of 9.42.4.

The authorized user may omit the required surveys if a laboratory enters into a period of time when radioactive materials are not in use. (See NOTE below.) However, the authorized user must make an entry noting the special circumstances in the logbook in place of each of the normal surveys.

NOTE: The authorized user must survey the storage areas for radioactive materials at least once each month and document the results.

Logbook Audit

The logbook of surveys must be available to the Radiation Safety Office and/or Department of Health inspectors.

Keep the survey records for at least three years. (WAC 246-221-230(9)(c)) See BPPM 90.01.

SURVEY INSTRUMENTS

Portable survey instruments are used to detect radioactive contamination in personnel (e.g., hands, clothes, shoes) as well as for laboratory surveys.

Selection Guide

The following table indicates appropriate detector application

Radionuclide

Radiation

Energy in MeV

Detector

14C

ß-

0.156

Thin window GM

32P

ß-

1.709

Thin window GM

35S

ß-

0.167

Thin window GM

45Ca

ß-

0.257

Thin window GM

51Cr

gamma

0.320

GM, thick NaI

60Co

gamma

1.17, 1.33

GM, thick NaI

125I

gamma

0.035

Thin NaI

131I

gamma, ß-

0.364/0.606

GM, thick NaI

22Na

gamma/ß+

0.511/0.545

GM, thick NaI

Alpha emitters,
i.e., 241Am, 239Pu

alpha ++

Various

Alpha probe

In general, for betas (e.g., 35S, 45Ca), choose a pancake probe detector (preferable) or at least a GM detector with a thin window (window thickness of 1.5-2.0 mg/cm2).

For detection of high energy gammas (e.g., 51Cr and 131I), a GM detector with window thickness exceeding 2 mg/cm2 or a thick crystal of NaI (2.54 cm x 2.54 cm) may be used.

For detection of low-energy gammas (125I) or X-rays, use a thin-crystal NaI detector (1-2 mm x 2.54 cm).

Calibration

Calibrate survey instruments at least once each year and after each service.

The Radiation Safety Office (RSO) provides calibrations free of charge upon request for survey meters that were approved by the RSO in advance of procurement. In such cases, the authorized user must furnish the RSO with a copy of the instruction manual.

An authorized user may elect to utilize the calibration services of another qualified provider. The authorized user must submit a copy of the calibration certification to the RSO immediately after calibration for records retention purposes. The annual calibration frequency must still be maintained.

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.

Questions

Direct any questions regarding the purchase of survey instruments to the Radiation Safety Office.

Notification

Report the acquisition of new survey instruments to the Radiation Safety Office for purposes of updating the database and scheduling required annual calibrations.

SECURITY OF RADIOACTIVE MATERIALS

Security of sources of ionizing radiation remains a major interest of the Nuclear Regulatory Commission and the Washington State Department of Health. The focus of this interest is radioactive materials (RAM).

Radioactive materials (RAM) and radiation machines laboratories must be either locked or attended at all times.

Enforcement of security for RAM involves progressive citations:

The RSO gives two such notices to any authorized user before proceeding to the next citation level.

The RSO maintains a logbook record of all such letters of notification.

See the PDF master form:
9.42.8: Laboratory Survey
Print or complete onscreen and print as needed