Example 4.7. Example of Performance Specifications for a Bioassay Laboratory

DOE-STD-1121-98

Example 4.7 (continued)

Example of Performance Specifications for a Bioassay Laboratory

Other factors that should be negotiated and put into the statement of work include turnaround time(s)

for analytical results, especially for special bioassay; the need for prompt notification of results that

exceed certain levels; and length of storage time for unused portion of samples or final analyzed

preparation of samples (e.g., counting planchet) to allow for reanalysis or recounting of samples, if

necessary.

The radiobioassay laboratory is required to maintain a QA manual that outlines responsibilities and

also provides requirements for data control, document control, maintenance/test equipment

calibration and checks, procedures, training, corrective action in the event of noncompliance, and

traceability to standardizing bodies such as the National Institute of Standards and Technology

(NIST) (when available).

All instruments used for the analysis of the radionuclides in the bioassay program shall be properly

"response"-checked before being used to analyze the DOE site's samples. The results of the response

checks shall be documented for each instrument that requires calibration (e.g., radiation detectors,

scales, balances, etc.). All radiation detection instruments used for analysis of the radionuclides in

the bioassay program shall be calibrated at least annually using NIST-traceable standards when they

are available. A NIST certificate for all standards (when available) shall be retained by the

radiobioassay laboratory and shall be made available to the DOE site for review.

Additional Quality Control Factors

Yields: The average yields determined for plutonium and strontium separated from urine and feces

shall be at least 50% without restrictions, and at least 25% if it is determined that contractual

minimum detectable amounts can be met. For americium and uranium, the average yields shall be at

least 40% and 20%, respectively.

Resolution: The resolution of "-particle spectrum energy peaks shall be less than 100 keV full width

at half maximum.

Contamination: The results of the reagent blanks shall be at least low enough to allow meeting the

minimum detectable amounts. Any trend or sudden change towards increase in activity in blanks or

their standard deviations that may cause the contractual minimum detectable amounts to be exceeded

should be investigated and the cause eliminated.

Contamination of the final fraction of one element with the nuclide of another element becomes

important in alpha-particle spectrometry, particularly when it involves nuclides with alpha energies

that cannot be resolved (energy peaks within one full width at half maximum of each other).

Whenever potentially interfering foreign nuclides appear in the final fraction of any element, the

cause for the contaminations should be identified and eliminated. If the magnitude of the

contamination adversely affects the result, work shall be stopped until the problem is solved.

However, work stopage is not warranted for an isolated suspected contamination event.

(continued)