Information Notice 1993-10, Dose Calibrator Quality Control

Dose Calibrator Quality Control

ML031080166
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	02/02/1993
From:	Cunningham R NRC/NMSS/IMNS
To:
References
IN-93-010, NUDOCS 9301270077
Download: ML031080166 (7)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS

WASHINGTON, D.C. 20555 February 2, 1993 NRC INFORMATION NOTICE NO. 93-10: DOSE CALIBRATOR QUALITY CONTROL

Addressees

All Nuclear Regulatory Commission medical licensees.

Purpose

This notice is provided to alert recipients to problems concerning dose

calibrator quality control tests, identified by NRC inspectors during

inspections of medical programs, and also to emphasize the importance of

quality control procedures for equipment used to assay patient doses. It is

expected that-licensees will: review this information for applicability to

their programs; distribute this notice to those responsible for radiation

safety and medical quality assurance, including technologists; and consider

actions to preclude similar situations from occurring at their facilities.

However, the suggestions contained in this notice do not constitute any new

NRC requirements, and no written response is required.

Description of Circumstances

During recent NRC inspections of medical facilities, inspectors found

deficiencies and irregularities in the performance and recording of dose

calibrator quality control tests. The most frequently occurring deficiencies

involve the constancy checks and linearity tests. However, there have also

been citations for failure to perform accuracy tests and determine geometric

independence. In some instances, the licensee did identify a malfunctioning

dose calibrator, but no corrective action was taken even though the error or

deviation exceeded allowable limits. Other problems included: failure to

instruct supervised individuals in the proper use of the dose calibrator;

failure to perform constancy checks when emergencies required the dose

calibrator to be used during non-routine periods such as weekends and

holidays; and failure to analyze the data, as required.

Discussion

Quality control checks of dose calibrators used to assay patient dosages are

essential to ensure that the dosage administered to a patient is the same as

the prescribed dosage. Medical personnel administering dosages should be

aware of the applicable NRC regulations (10 CFR 35.50) and any specific

related license conditions. Licensees are encouraged in Regulatory Guide

10.8, Rev. 2, to develop procedures that provide an even higher level of

confidence that the correct dosage is administered. For example, Regulatory

Guide 10.8, provides a model procedure for meeting the requirement. The guide

proposes a smaller percent deviation as a trigger level, so the licensee can

9301270077 S

IN 93-10

February 2, 1993 take action before the regulatory limit is reached. However, if it committed

to the regulatory guide procedures as part of a license application, the

licensee must comply with the more restrictive requirement. Licensees are

responsible for the instruction and supervision of individuals to ensure that

they know and follow the proper procedures for dose calibrator checks.

1. Constancy Checks

Constancy means reproducibility in measuring the activity of a known source

over a long period of time. The dose calibrator is required

(10 CFR 35.50(b)(1)) to be checked for constancy with a dedicated check source

at the beginning of each day of use. This includes weekends and holidays, if

radiopharmaceuticals are administered to a patient. During recent NRC

inspections, inspectors determined that licensees had failed to perform these

required checks because part-time technologists who worked only on weekends or

staff technologists called in on weekends had not been properly instructed by

the licensee and did not know that these checks were to be performed on

weekends.

The reference source used for the constancy check must be assayed at a

frequently used setting. Regulatory Guide 10.8 suggests using two or more

sources with different photon energies and activities, although one source

meets the requirement. The rule requires that the licensee determine the

constancy of the dose calibrator under an actual condition of use. Since most

medical licensees use technetium-99m for patient-dosage administrations more

frequently than any other isotope, such licensees should check the technetium-

99m setting, on each day of use, with a dedicated check source. It is

recommended that dose calibrators having both pre-adjusted controls (i.e.,

push buttons) and variable potentiometers be tested on both the variable

potentiometer technetium-99m (or other frequently used isotope) setting and

the pre-adjusted control. Discrepancies or fluctuations between the two

controls, when tested for constancy with the same check source, may be

indicative of equipment malfunction. Licensees must plot or log (10 CFR

35.50(e)(1)) the measured activity of each source and compare it to the

calculated activity, based on decay of the dedicated check source. If the

error between the two values exceeds 10 percent, the dose calibrator must be

repaired or replaced (10 CFR 35.50(d)).

2. Accuracy Test

The accuracy test ensures that the activity is within 10 percent of a given

calibrated reference source whose activity has been determined by the

manufacturer to be within 5 percent of the activity stated by the National

Institute of Standards and Technology (NIST) or by the supplier who has

compared that source to a source that was calibrated by NIST. At least two

sealed sources with different principal photon energies, one of which has a

principal energy between 100 keY and 500 keY, must be used to determine

accuracy upon installation, and at least annually thereafter

(10 CFR 35.50(b)(2)). The regulations require that the activity is at least

10 uCi for Ra-226 and 50 ACi for any other photon-emitting radionuclide. For

best accuracy, the lower energy reference standards should be in vials of

similar thickness to those for actual samples. As with the. constancy check

IN 93-10

February 2, 1993 a trigger level of

and linearity tests, Regulatory Guide 10.8 suggests if the error exceeds

5 percent difference but the requirement states that or replaced.

10 percent then the dose calibrator must be repaired

3. Linearity Tests

can indicate the correct

The linearity test ensures that the dose calibrator dose that will be

activity over the range of use between the highest dose calibrator is to be

administered to a patient and 10 microcuries. The

thereafter

tested for linearity upon installation and at least quarterly

determined linearity over

not

(10 CFR 35.50(b)(3)). Licensees have frequently frequently used for the

the entire range of use. Technetium-99m is most

and it is

linearity test because of its availability and short half-life, 10 percent, dosage

relatively inexpensive. If the percent deviation exceeds

Regulatory Guide 10.8 suggests a

readings must be mathematically corrected. to this level in

trigger level of +5 percent but unless the licensee commits percent variation.

allows for a 10

the license application, the requirement

4. Geometry Dependence

activity does not

Testing for geometry independence ensures that the indicated

be performed, upon

change with volume or configuration. This test mustconfigurations for which it

installation, over the range of volumes and volume in Regulatory Guide 10.8, will be used (10 CFR 35.50(b)(4)) and, as suggested for injections.

should be done using a syringe that is normally used kits should also do the

Licensees who use generators and radiopharmaceutical to the

test using a vial similar in size, shape, and construction testing performed by

radiopharmaceutical kit vials normally used. Geometry manufacturer has

the manufacturer may be acceptable, provided that the the dose calibrator'

included all volumes and volume configurations for which keeps a record of

will be used at the licensee's facility and the licensee

this test.

appropriate checks

Licensees are also required (10 CFR 35.50(c)) to perform after battery

and tests following adjustment (e.g., a constancy check it is not necessary-to

replacement) or repair of the dose calibrator. Whereas relocated

check geometry dependence if the dose calibrator is physically

instrument panel, it

within the department or following minor repairs to the done that might affect

is appropriate to do the geometry check if repairs are linearity and

the response of the chamber. It is appropriate to conduct

accuracy tests following any repairs to the dose calibrator.

(RSO) and Radiation

It is the responsibility of the Radiation Safety Officerperformed. Licensees

Safety Committee (RSC) to ensure that these checks are responsible for

are reminded that 10 CFR 35.21 requires that an RSO be that radiation safety

implementing the radiation safety program and ensuring procedures and

activities are being performed in accordance with approved byproduct

regulatory requirements in the daily operation of the licensee's

that an RSC perform

material program. In addition, 10 CFR 35.22 requires

periodic reviews, to oversee the use of byproduct material.

/

IN 93-10

February 2, 1993 No written response is required by this information

questions about this matter, please contact the notice. If you have any

office or this office. appropriate NRC regional

Richard E. Cunningham, Director

Division of Industrial and

Medical Nuclear Safety

Office of Nuclear Material

Safety and Safeguards

Technical contact: Patricia K. Holahan, NMSS

(301) 504-2694 Attachments:

1. List of Recently Issued

NMSS Information Notices

2. List of Recently Issued

NRC Information Notices

g - z r

Attachment 1 IN 93-10

February 2, 1993 LIST OF RECENTLY ISSUED

NMSS INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

93-07 Classification of Trans- 02/01/93 All Licensees required to

portation Emergencies have an emergency plan.

93-05 Locking of Radiography 01/14/93 All Nuclear Regulatory

Exposure Devices Commission industrial

radiography licensees.

93-04 Investigation and Re- 01/07/93 All U.S. Nuclear Regulatory

porting of Misadministra- Commission medical

tions by the Radiation licensees.

Safety Officer

93-03 Recent Revision to 01/05/93 All byproduct, source, and

10 CFR Part 20 and special nuclear material

Change of Implementa- licensees.

tion Date to

January 1, 1994

92-84 Release of Patients 12/17/92 All Nuclear Regulatory Com- Treated with Temporary mission Medical Licensees.

Implants

92-72 Employee Training 10/18/92 All U.S. Nuclear Regulatory

and Shipper Registra- Commission Licensees.

tion Requirements for

Transporting Radioactive

Materials

92-62 Emergency Response 08/24/92 All U.S. Nuclear Regulatory

Information Require- Commission Licensees.

ments for Radioactive

Material Shipments

92-58 Uranium Hexafluoride 08/12/92 All fuel cycle licensees.

Cylinders - Deviations

in Coupling Welds

1%J .

Attachment 2 IN 93-10

February 2, 1993 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

93-09 Failure of Undervoltage 02/02/93 All holders of OLs or CPs

Trip Attachment on for nuclear power reactors.

Westinghouse Model DB-50

Reactor Trip Breaker

93-08 Failure of Residual 02/01/93 All holders of OLs or CPs

Heat Removal Pump for nuclear power reactors.

Bearings due to High

Thrust Loading

93-07 Classification of Trans- 02/01/93 All Licensees required to

portation Emergencies have an emergency plan.

93-06 Potential Bypass Leak- 01/22/93 All holders of OLs or CPs

age Paths Around Filters for nuclear power reactors.

Installed in Ventilation

Systems

93-05 Locking of Radiography 01/14/93 All Nuclear Regulatory

Exposure Devices Commission industrial

radiography licensees.

93-04 Investigation and Re- 01/07/93 All U.S. Nuclear Regulatory

porting of Misadministra- Commission medical

tions by the Radiation licensees.

Safety Officer

93-03 Recent Revision to 01/05/93 All byproduct, source, and

10 CFR Part 20 and special nuclear material

Change of Implementa- licensees.

tion Date to

January 1, 1994

93-02 Malfunction of A Pres- 01/04/93 All holders of OLs or CPs

surizer Code Safety for nuclear power reactors.

Valve

93-01 Accuracy of Motor- 01/04/93 All holders of OLs or CPs

Operated Valve Diagnostic for nuclear power reactors.

Equipment Manufactures

.by Liberty Technologies

OL = Operating License

CP = Construction Permit

IN 93-10

February 2, 1993 No written response is required by this information notice. If you have any

questions about this matter, please contact the appropriate NRC regional

office or this office.

Richard E. Cunningham, Director

Division of Industrial and

Medical Nuclear Safety

Office of Nuclear Material

Safety and Safeguards

Technical contact: Patricia K. Holahan, NMSS

(301) 504-2694 Attachments:. > v

1. List of Recently Issued

NMSS Information Notices

2. List of Recently Issued

NRC Information Notices

DOCUMENT NAME: 93-10.IN

E. Kraus

TechEd

11/23/92

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• See previous concurrence

OFC :IMAB :IMAB* :IMAB* :IMOB* :OGC* :DD/IMNS* :D/IMNS*

NAME :PHolahan:rj:LWCamper :JEGlenn :FCombs :STreby :JTGreeves:RECunningham

DATE :01/21/93 :12/14/92 :12/17/92 :12/18/92 :01/15/93 :01/25/93 :01/25/93 OFFICIAL RECORD COPY