Tenn. Comp. R. & Regs. 0400-20-06-.07 - ANALYTICAL X-RAY INSTALLATIONS

(1) Equipment.

(a) The leakage radiation from the tube housing shall not exceed a radiation level of 2.5 milliroentgens in 1 hour at 5 centimeters from the surface of the tube housing at any specified tube rating.

(b) Radiation originating within the high voltage power supply (i.e., transformer and rectifiers) shall not exceed a radiation level of 0.5 milliroentgen in 1 hour at every specified rating at a distance of 5 centimeters from the housing of the power supply.

(c) A warning light with the notation "X-Ray On," or equivalent shall be located on the control panel and shall light only when the x-ray tube is activated. This light shall be a fail-safe design or administrative controls shall be exercised to ensure operations will not continue without a proper functioning warning light. On equipment installed after October 2, 1978, this device shall be a fail-safe design.

(d) The x-ray accessory apparatus shall include a beam trap or other barrier with sufficient shielding so that the dose rate due to the transmitted primary beam does not exceed 0.25 mrem/hr at 5 centimeters under normal operating conditions. The dose rate may be difficult to evaluate in the presence of scattered radiation, however, this requirement shall be considered met if the inherent shielding of the trap or barrier is at least equivalent to the thickness of lead specified in Table RHS 3-5 for the maximum rated anode current and potential.

Table RHS 3-5 THICKNESS OF LEAD REQUIRED FOR A PRIMARY BEAM BARRIER LOCATED 5 CENTIMETERS FROM THE FOCAL SPOT

Anode current	Thickness of lead (mm)
(mA)	50 kVp	70 kVp	100 kVp
20	1.5	5.6	7.7
40	1.6	5.8	7.9
80	1.6	5.9
100	1.7

(e) A light or indicator in a conspicuous location near the tube housing assembly shall be used to indicate when the x-ray tube is on. This light or other indicator shall be of failsafe design or administrative controls shall be exercised to ensure operations will not continue without proper functioning of this light or indicator. On equipment installed after October 2, 1978, this device shall be of fail-safe design.

(f) In addition to any signs or labels required in Rule 0400-20-05-.111, a sign or label shall be placed on or adjacent to each x-ray tube housing and shall be located so as to be clearly visible to any individual who may be working in close proximity to the primary beam path. The sign or label shall bear the words:

"CAUTION - HIGH INTENSITY X-RAY BEAM"

(g) Where couplings exist, e.g., between the x-ray tube and the collimator of the diffractometer, etc., they shall prevent radiation from escaping the coupling.

(h) Each port of the radiation source housing shall be provided with a beam shutter interlocked with the x-ray accessory apparatus coupling, or collimator, in such a way that the port will be open only when the collimator or coupling is in place. Shutters at unused ports shall be secured to prevent inadvertent opening.

(i) Open beam x-ray equipment

1. All shutters shall be provided with a "shutter open" indication of fail-safe design.

2. Radiation levels in the vicinity of controls and adjustments of the x-ray accessory apparatus used during normal operation shall be such that the operator's exposure shall not exceed in one hour 37 mrem to the hands or 2 mrem to the whole body, gonads, bloodforming organs, or lens of the eye.

3. A guard or interlock which prevents entry of any part of the body into the primary beam path should be utilized.

4. The operator shall be in immediate attendance at all times when the equipment is in operation except when the area is locked to protect against unauthorized or accidental entry.

5. When not in use, equipment shall be secured in such a manner as to be inoperable by unauthorized persons.

(j) Enclosed beam x-ray equipment

1. The radiation source, sample, detector and analyzing crystal (if used) shall be enclosed in a chamber or coupled chambers that cannot be entered by any part of the body during normal operation.

2. The sample chamber closure shall be interlocked with the x-ray tube high voltage supply or a shutter in the primary beam so that no x-ray beam can enter the sample chamber while it is open unless the interlock has been conspicuously and deliberately defeated. The interlock required by this section shall be of failsafe design or adequate administrative controls shall be exercised to ensure operations will to continue without a proper functioning interlock.

3. The exposure level at 5 centimeters from the tube housing apparatus complex shall not exceed 2.5 milliroentgens per hour during normal operation.

(2) Operation of equipment.

(a) The registrant shall not permit any individual to operate or maintain analytical x-ray equipment until such individual has received instruction in and demonstrated competence as to:

1. Identification of radiation hazards associated with the use of the equipment;

2. Significance of the various radiation warning and safety devices incorporated into the equipment, or the reasons they have not been installed on certain pieces of equipment and the extra precautions required in such cases;

3. Proper operating procedures for the equipment;

4. Symptoms of an acute localized exposure; and

5. Proper procedures for reporting an actual or suspected exposure.

(b) Procedures and apparatus utilized in beam alignment shall be designed to minimize radiation exposure to the operator.

(c) Written operating procedures and emergency procedures pertaining to radiation safety shall be established for each facility and shall be conspicuously posted in a location near each unit of analytical x-ray equipment.

(d) Only trained personnel shall be permitted to install, repair, or make modifications to the x-ray generating apparatus and the tube housing apparatus complex.

(e) Any temporary alteration to safety devices, such as by-passing interlocks or removing shielding shall be:

1. Approved in advance by the radiation safety officer.

2. Specified in writing and posted near the x-ray tube housing so that other individuals will know the existing status of the x-ray apparatus.

3. Terminated as soon as possible.

4. Recorded and the record maintained for inspection by the Division. This record should contain such information as date alteration was made, type of alteration, length of time unit remained in the altered condition, and signed by the individual who made the alteration and the individual who restored the unit to original condition.

(f) Tests of all safety devices such as interlocks, shutters, and warning lights shall be conducted at intervals not to exceed 3 months for all operable analytical x-ray equipment. Records of such tests shall be maintained for inspection by the Division.

(g) Interlocks shall not be used to de-activate the x-ray tube, except in an emergency or during testing of the interlock system. After such shut-off, it shall be possible to restore the machine to full operation only from the control panel.

(h) Surveys and personnel monitoring shall be provided to insure compliance with the requirements of Chapter 0400-20-.05 (See Rules 0400-20-05-.50, 0400-20-05-.55, 0400-20-05-.56, 0400-02-05-.60, 0400-20-05-.70, 0400-20-05-.71(1), 0400-20-05-.130, 0400-20-05-.132, and 0400-20-05-.135 ).

(3) In addition to the requirements of paragraphs (1) and (2) of this rule, the following requirements apply to open-beam, hand-held, analytical X-ray devices:

(a) Procedures.

All registrants possessing open-beam, hand-held, analytical devices shall have available for review by the Division operating policies and procedures that contain measures to ensure that: ⁹

1. Radiation protection is provided equivalent to that afforded in subparagraph (1)(d) of this rule. This shall be in the form of an operating procedure that contains, at a minimum:

(i) The operator's hands will not approach the primary beam;

(ii) The operator will not hold the sample during operation of the hand-held x-ray device;

(iii) The operator will not aim the primary beam at him/herself or at any individual during operation of the device; and

(iv) Before energizing the device, the operator will ensure that no person is within two meters of the device or sample being tested.

2. If the safety devices, which are known as the "X-ray On" warning light and the tube housing "X-ray On" indicator light, as outlined in subparagraphs (1)(c) and (1)(e) of this rule, are not of a fail-safe design, administrative controls shall be put in place in the form of an operating procedure that shall include, at a minimum:

(i) Discussion of the warning light(s) safety mechanism on the device, the rationale behind subparagraphs (1)(c) and (1)(e) of this rule, the absence of the fail-safe design on the device, and the potential risks to the operator should the warning light(s) fail;

(ii) Training the operator to visually verify that the warning light(s) is correctly working when the device is known to be generating X-rays;

(iii) Training the operator to recognize warning light failure. For example: warning light(s) not functioning when the device is known to be generating X-rays, or if one of several warning lights is not operating;

(iv) Proper procedures for reporting an actual or suspected warning light failure; and

(v) If failure of the warning light, or any one of the warning lights if there are multiple warning lights, is confirmed, the analyzer will immediately be removed from service and returned to the manufacturer for repair. Return to service will not be permitted until necessary repair has been performed, and the maintenance record for the device updated. Such maintenance records shall be made available upon request by the Division.

3. Operator radiation exposure is as low as reasonably achievable. For example, use of ancillary equipment when possible, such as a sample holder.

(b) Extremity Monitoring.

The registrant shall provide and require individual personnel monitoring with extremity dosimeters for all operators of the hand-held device in compliance with Chapter 0400-20-05. Extremity monitoring may be discontinued after one year if the results of the personnel monitoring demonstrate that the operator of the hand-held device is not likely to receive a dose in excess of 10 percent of the limits in Rule 0400-20-05-.50, as outlined in Rule 0400-20-05-.71. The registrant shall maintain records of doses received by all individuals for whom monitoring was required pursuant to Rules 0400-20-05-.71 and 0400-20-05-.135.

(c) Training.

In addition to the training requirements of subparagraph (2)(a) of this rule, the registrant shall provide training for all users and operators on the requirements of subparagraph (a) and (b) of paragraph. Records of all user and operator training shall be maintained and made available for review by the Division. Training records shall include:

1. The date the training was provided;

2. The name of each individual trained (printed) and their signature;

3. The name and dated signature of the individual providing the training;

4. The topics covered in the training (or an attachment of the training material); and

5. The duration of the training.

⁹ This part is intended to apply to units that are hand-held. Analytical units designed to be hand-held but operated in a fixed configuration and not hand-held shall be subject to the requirements of subparagraph (1)(d) of this rule.

Notes

Tenn. Comp. R. & Regs. 0400-20-06-.07

Original rule filed February 22, 2012; effective May 22, 2012. Amendments filed September 10, 2019; effective 12/9/2019.

Authority: T.C.A. §§ 4-5-201, et seq.; 68-202-101, et seq.; and 68-202-201, et seq.