ML20106B273

Proposed TS 6.5, Generation of Medical Therapy Facility Beam for Human Therapy

ML20106B273
Person / Time
Site:	MIT Nuclear Research Reactor
Issue date:	09/23/1992
From:	MASSACHUSETTS INSTITUTE OF TECHNOLOGY, CAMBRIDGE
To:
Shared Package
ML20106B080	List: ML20106B076 ML20106B273
References
NUDOCS 9210010094
Download: ML20106B273 (16)

Text

_ __ ._. . . _ . . . __ _ _ ._ _ _ . _..

W l

6. EXPERIMENTS 6.1 General Experiment Criteria .... ............................................6-1 6.2. In-Core Cryostat . . .. . .... .. .. . ...................................6-8 6.3 Sodium Subassembly for Fast Neutron Spectrum Facility. ..... . .. . .. 6-14 6.4 Closed-Loop Control Systems . ... ... . . ..... . .. ....... ... . . . . . . . . . . 6- 17 6.5 Generation of Medical Therapy Facility Beam for llaman Therapy ....... 6-21 t

l l- 7. ADMINISTRATIVE CONTROLS 7.1 Respon si bili ty .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7- 1 7.2 Reactor Staff Organization ...... ... ... .... ......... .. . .......... ..... 7-4 7.3 Reactor S taff Qualifications . . . . . . . . . . . . . . . . . . . . ........... ........... 7-6 7.4 Re training and Replacement Training.. . .... ... . ... ................ ..... 7-8 7.5 Review . . .. . ... . . . ..... . .. . .. . ... ..... ....... .. 7-9 7.6 Action to be Taken in the Event of an Abnormal Occurrence......... ..... 7-18 7.7 Action to be Taken if a Safety Limit is Exceeded........ . ...... . ..... . 7-19 7.8 Operating Proced ures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-20 7.9 Experiment Approval Procedures. .. . . . .. . .. ........ .......... 7-22 7.10 Radiation Protection Prograni ... ... . ..... . . .. .. ................... 7-24

7.11 Security Program... . . . .... ... ....................................7-25 7.12 Records Retention.. . . . ......... .. .. . ..............................7-26 7.13 Plant Reporting Requirements. . . . . . . . . . . . .. . . .. . . . . . . .. . . . . . . .. . . . . . . . . . 7-28 '

i i

i 1H S R#-0-91-17 MAR 061992 9m10010094 9;/0923 0 PDR ADOCK 0500 P

r++v++ p-% <-s g.- w -

• 7--a e ~w - - p'- w L

. - - - ~ _- - -. . . - - .-

T 6.5 Generation of Medical Therany Facility Beam for Human Therany Applicability This specification applies solely to the generation of the medical therapy facility beam for the treatment of human patknts. It does not apply to any other use of the medical therapy facility and/or its beam.

Obiective To provide for the protection of the public health and safety by ensuring that patients are treated in accordance with the treatment plan established by their phyrician and that the ALARA principle is observed for all non-therapeutic radiation exposures.

Snecification

1. Patients accepted for treatment shall have been referred by written directive from NRC Medical Use Licensee No. 20-03857-06 or from any other medical use licensee that has been similarly authorized by NRC to utilize the MIT Research Reactor's. Medical Therapy Facility beam for human therapy.

2. All medical treatments, including irradiations and analyses of the neutron capture agents in the patients, are the responsibility of the licensed physician in charge of the therapy and the medical physicists from the NRC-licensed medical center. The e Massachusetts Institute of Tect:nology is only responsible for delivery of the-desired radiation fluence as requested by the medical physicist in charge of the therapy. Before the start of a therapy, both a certified medical physicist and the Director of the Nuclear Reactor Laboratory, or his designate, must . gree that the therapy can be initiated. A certified medical physicist is responsible for monitoring L the therapy and for directing its termination. Ilowever, a radiation therapy can also be terminated at any time if either the physician or the NRL Director, or their designates, judge that the therapy should be terminated.

3. It shall be possible to initiate a minor scram of the reactor from a control panel 6-21 SR# 0-91-17 MAR 061992 l

located in the medical therapy facility area. In the event that the medical facility minor scram is inoperable, it shall be acceptable to use one of the control room scrams via communication with the reactor operator as a temporary means of satisfying this provision. Use of this temporary provision is limited to seven consecut:ye working days.

4. Access to the medical therapy facility shall be controlled by means of the shield door located at its entrance.

5. The following features and/or interlocks shall be operable:

(a) An interlock shall prevent opening of the shutters that control beam delivery unless the medical therapy facility's shield door is closed.

(b) The shutters that control beam delivery shall be interlocked to close automatically upon opening of the medical therapy facility's shield door.

~

(c) The shutters that control beam delivery shall be designed to close I automatically upon failure of either electric power or on low air pressure if the shutter is operated pneumatically.

(d) Shutters that control beam delivery and that are normally pneumatically-operated shall, in addition, be designed for manual closure.

(e) It shall be possible to close the shutters that control beam ~

delivery from witisin the medical therapy facility.

6. Each of the shutters that controls beam delivery shall be equipped with a light that indicates the status of the shutter. These lights shall be visible at the medical therapy facility's local cc:wrol panel. In the event of a status light malfunction,it shall be acceptable to use the affected shutter provided that an alternate means of verifying position is available. Use of this alternate means of shutter e Position verification is limited to seven consecutive working days.

6-22 S R#-0-91-17 MAR 061992

-1

i

7. The medical therapy facility shall be equipped with a monitor that provides a visual indication of the radiation level within the facility, that indicates at the local control panel, and that provides a local, audible alarm.

(a) This radiat.. n monitor shall be equipped with a backup power supply such as the reactor emergency power system or a battery.

(b) -This radiation monitor shall be checked for proper operation by means of a check source within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to any patient irradiation.

l (c) This radiation monitor shall be calibrated quarterly.

(d) Th; andible alarm shall be set so as to alert personnel if radiation levels in the medical therapy facility exceed that which exists with the reactor at full power and with ':

shutters that control beam delivery in the closed position by more than a factor of three. This monitor and/or its alarm may he disabled once the medical therapy room has been searched and secured, such as is done immediately prior to initiation of patient therapy. If this is done, the monitor and/or its alarm shall be interlocked so that they become functional upon opening of the medical therapy facility's shield door.

(c) In the event that this monitor is inoperable, personnel entering the medical therapy facility shall use either portab!c survey insne.aents or audible alarm personal dosimeters as a temporary means of satisfying this provision. These instruments / dosimeters shall be in calibration as defined by the MIT Research Reactor's radiation protection program. ~ Use of these instruments / dosimeters as a temporary means of satisfying this provision is limited to seven consecutive working days.

6-23 S R#-0-91-17 MAR 061992 l

l

8. An intercom or other means of two-way communication shall be operable between the medical therapy facility and the reactor control room.

9. It shall be possible for personnel monitoring a patient to open the medical therapy facility's shield door manually.

10. It shall be possible to observe the patient through both a viewing port and by means of a closed-circuit TV camera. Both methods of patient visualization shall be operable at the outset of any patient irradiation. Should either fait during the irradiation, the treatment may be continued at the discretion of either the patient's physician or medical physicist. Adequate lighting to pe.7 nit such viewing shall be assured by the provision of emergency lighting.

I 1. The total radiation fluence delivered by the mediol tt apy facility beam as measured by on-line beam monitors shall not exceed that prescribed in the patient treatment plan by more than 20%. The treatment is normally delivered in fractions in accordance with standard practice for human therapy. The 20% criterion applies to the sum of the radiation fluences associated with all fractions in a given treatment plan. A criterion of 30% applies to the difference between the administered and prescribed fluence for any given week (seven ec- cutive days).

Finally, if the treatment consists of three or fewc. .ractions, then a

~

criterion of 10% shall apply.

12. The following interlocks or channels shall be tested at least monthly and prior to treatment of human patients if the interlock or channel has been repaired or deenergized:

Interkrk or Channel Surveillance a) Medical therapy facility minor scram Scram test b) Shutters will not open unless Operational test shield door is closed 6-24 SR#-0 91-17 MAR 061992

c) Shutters close upon both manual and Operational test automatic opening of shield door d) Shutters close on loss of electrical Operations test power and reduction of pressure in pneumatic operators,if applicable c) Manual closure of pneumatic shutters Opemtional test f) Feasibility of shutter closure Operational test from within the facility g) Shutter status lights Functional check h) Radiation monitor alarm Operational test i) Radiation monitor and/or alarm Functional check enabled upon opening of shield door In addition to the above, the medical therapy facility minor scram shall be tested prior to reactor startup if the reactor has been shut down for more than sixteen hours.

13. Manual operation of the medical therapy facility's shield door shall be verified semi-annually.

14. Use of the medical therapy facility beam shall be subject to the following:

a) A calibration check of the beam and a functional check of the beam monitors that are described in provision 11 of this specification shall be made weekly for any week that the beam will be used for human therapy. These checks shall be made prior to any patient irradiation for a given week. In addition, a calibration check shall be performed prior to any patient irradiation in the event that any compotient of a given beam 6-25 SR#-0 17 MAR 061992 l

~ . . . .. _ - _ _ _ _ _

4 l design has been replaced. Finally, a calibration and a functional check shall be performed prior to any patient irradiation in the event of a design modification.

b) A characterization of the beam shall be performed every six months for any six-month in!crval that the beam will be used for human therapy. This six-month characterization shall be made prior to any patient irradiation for a given six-month interval. A characterization shall also be performed prior to any patient irradiation in the event that any component of a given beam design has been modified. As part of the characterization procers, the proper response of the beam monitors that are described in provisi<m 11 of this specification shall be verified.

c) A calibration of the beam monitors that are described in provision 11 of this specification shall be performed at least once every two years for any two year interval that the beam will be used for human therapy. The two year calibration shall be made prior to any patient irradiation during any given two year interval.

15. Maintenance, repair, and modification of the medical therapy facility shall be perfomied under the supervision of a senior reactor operator who is licensed by the U.S. Nuclear Regulatory Commission to operate the MIT Research Reactor. The

' medical therapy facility' includes the beam, beam shutters, beam monitoring equipment, medical therapy facility shielding, shield door, and patient viewing 6-26 SR#-0-91-17 MAR 061992

b equipment. All modifications will be reviewed pursuant to the.

requirements of 10 CFR 50.59. The operating couch, patient positioning equipment, medical instrumeats, and other equipment used for the direct medical support of the patient are not considered part of the medical therapy facility for purposes of this provision, except insofar as radiation safety (i.e.,

activation and/or contamination) is concerned.

16. Personnel who are not licensed to operate the MIT Research Reactor but who are responsible for either the medical therapy or the beam's design including _

construction and/or modiGeation may operate the controls for the medical therapy facility beam provided that:

(a) Training has been provided and proficiency satisfactorily demonstrated on the design of the facility, its controls, and the use of those controls.

Proficiency shall be demonstrated annually.

(b) Instmetions are posted at the medical therapy facility's local control panel that specify the procedure to be followed:

(i) to ensure that only the patient is in the treatment room before tuming the primary beam of radiation on to begin a treatment; (ii) if the operator is unable to turn the primary beam of radiation off with controls outside the medical therapy facility, or if any other abnonnal i

condition occurs. A direct:ye shall be included with these instructions to notify the reactor console operator in the event of any abnomulity.

(c) In the event that a shutter affects reactivity (e.g., the D2 0 shutter),

personnel who are not licensed on the MIT Research Reactor but who have been trained under this provision may operate that shutter provided that verbal pennission is requested and received from the reactor console 6-27 SR#-0-91-17 MAR 061992

operator immediately prior to such action. Emergency closures are an exception and may be made without first requesting permission.

Records of the training provided under subparagraph (a) above shall be retained in accordance with the MIT Research Reactor's training program or at least for three .

l years. A list of personnel so qualified shall be maintained in the reactor control j room.

17. Events defined as ' recordable' under definition 7 of this specification shall be recorded and the record maintained for five years. Events defined as

'misadministrations' under definition 8 t this specification shall be reported to the U.S. Nuclear Regulatory Commission (24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> verbal,15 day written report).

The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> verbal reports will be made to the Regional Administrator, Region 1, or his designate. The 15 day written reports will be sent to the NRC Document Control Desk with a copy to the Regional Administrator, Region I, or his designate.

, 18. The requirements of the Quality Management Program for the l

l Generation of Medical Therapy Facility Heam for lluman Therapy at the Massachusetts Institute of Technology Research Reactor shall be l

observed for any humar, therapy.

, Definitions 1.

1. The medical therapy facility is equipped with shutters that are used (i) to control l

beam delivery and (ii) to adjust the neutron energy spectrum of the beam. The former currently inclede lead, boral, and light water shutters as described in Reference 6.5-1. The heavy water blister tank, which is also described in l.

Reference 6.5-1, is an example of the latter. It is conceivable that these L designations may change should it be found desirable to alter the beam L

configuration. Accordingly, the phrase " shutters that control beam delivery" refers 6-28 SR#-0-91 MAR 061992 l

l

. - . - . - - - _ ~ . - _ - . - - - . - - - - -.

either to the aforementioned three existing shutters or to any future shutter or group thereof that provides an equivalent or greater reduction in beam intensity.

Shutter-effect analyses shall be documented through the standard safety review i process including, where appropriate, an SAR revision and submission to NRC l

under 10 CFR 50.59.

2. The term ' calibration check' refers to the process of checking the beam intensity and quality via one or more of the following: foil activation; use of a fission chamber, l use of an ion chamber, or an equivalent process. The purpose of a caribration check is to ensure that the beam has not changed in a significant way (e.g., energy spectrum or intensity) from the beam that was characterized. l

3. The term ' functional check of the beam monitors'shall consist of verifying that l

l system output is consistent (i 10%) with previously measured values upon.

i normalization to a common reactor neutronic power level.

4. The term ' characterization' refers to the process of obtaining the dose versus-Apth profile in phantoms as described in Reference 6.5-2 or an equivalent process. The l dose versus-depth profile from the surface of the phantom to a depth t least equivalent tr. 'he total thhkness of the body part to be treated on a central axis is deemed adequate for a characterization. Fast neutron, themial neutron, and gamma ray components are determined in a full characterization and monitors are i

normalized by this chuacterization. ,

5. The term ' calibration of the beam monitors' refers to the process whereby the beant monitors that are described in provision 11 of this specification are calibrated against instruments that measure dose including a tissue-egtJvalent chamber and a graphite or magnesium i

wall ionization chainber (or 'he equivalent to any of these three) that -

l.

6-29 SR#-0-91-17 MAR 061992 1

l

- ~ - - --+--,-,.---<- --- - . _ . ,.. -..-.,- - - - - , , -- - - , - n....,e , r n - - - -, ,

have in turn been calibrated by a secondary calibration laboratory.

6. 'the tern ' design modification' as applied to the medical therapy facility beam refers (a) to a change that is shown to alter the dose-versus depth profile of the fast neutrons, thermal neutrons, or gamma rays in the beam as sensed by the calibration check and (b) to a change that has the potential to increase l l

significantly the amount of activation products in the medical therapy facility when the beam is to be used for the treatment of human patients.

7. The term

• radiation fluenec* means the total fluence of neutrons and gamma radiation that is emitted in the medical therapy facility beam. The determination of the ratios of gamma, fast neutron, and thennal neutron fluences is part of the bearn characterization. Knowledge of these ratios allows the total radiation fluence to be monitored by the on-line detectors, which are neutron-sensitive. Compliance with the limits specified on radiation fluence by this specification is detennined by reference to the fluence monitored by these detectors.

8. The tc em ' recordable event' means the administration of:

(a) A radiation treatment without a written directive where a written directive is required and where the treatment i., appropriate; or (b) A radiation treatment where a written directive is required without the per treatment recording of administered radiation fluence in the appropriate L

i reconi; or (c) A treatment delivery for which the administered radiation fluence for any given fraction is 15'7c greater than prescribed.

9.~ The tenn ' misadministration' means the admir.istration of a radiation therapy:

N 6 30 SR#-0-91-17 MAR 061992 I c

. . L . :_ . ._ _ . _ _ . , _ , _. . , _ _ _ . _ _ _ _ , _ . . , . _ _ . _ , _ _ _ . _ . . _ _ , _ _ . . _ . _ _ . _ . . , - . . . . .

Involving the wrong patient, wrong mode of treatment, or wrong treatment  !

(a) site; or i

(b) When the treatment delivery is not in accordance with provision 11 of this specification.

10. The tem 1 ' written directive' means an order in writing for a specific patient, dated and signed by an authorized user physician prior to the administration of radiation and which specifies the treatment slie, the total radiation fluence, radiation fluence per fraction, and overall treatment period.

I 1. The term ' human therapy' means radiation treaunents that are of direct therapeutic benefit to the patient and/or part of investigatory studies that involve humans.

12. The tenn ' certified medical physicist' means a medical phyricist certified in either L radiological physics or therapi utie radiation physics by the American Board of Radiology, or in therapeutic radiation physics by the American lloard of Medical Physics.

Basis The stipulation that patients only be accepted from NRC Medical Use Licensee No.

20-03857-06 or from any other medical use licensee that has been similarly authorized by NRC to utilize the MIT Research Reac'or's Meuical Therapy Facility beam for human therapy, ensures that medical criteria imposed by NRC on such licensees for the use of the MIT Resea'th Reactor's m ydical therapy facility beam for human therapy will be fulfilled.

The second orovision delineates the division of responsibilities between the Massachusetts Institute of'lechnology and the medicallicensee that refers the patient. Also,it establishes l administrative authority and protocol for initiating and temiinating a radiation therapy.

1

'I he requirement that it be possibic to initiate a minor scram from a control pane!

located in the medical therapy facility area assures the attending physician and/or medical physicist of the capability to terminate the treatment immediately should the need arise. The l 6-31 SR#-0-91-17 MAR 061992 .

c provision that access to the medical therapy facility be limited to a single door ensures that there will be no inadvertent entries. The various interlocks for the shutters that control beam delivery ensure that exposure levels in the medical therapy facility will be minimal prit r to entry by personnel who are attending the patient. The shutter-indication lights serve to notify personnel of the beam's status. The provision for a radiation monitor ensures that personnel will have information available on radiation levels in the medical therapy facility prior to entry. The purpose of this monitor's audible alarm is to alert personnel to the presence of elevated radiation levels, such as exist when the shutters that control beam delivery are open. This monitor and/or its alarm may be disabled once the medical therapy facility has been searched and secured so that it will (1) not disturb a patient and (2) not distract attending personnel. The monitor and/or its alarm are interlocked with the shield door so that they are made functional upon opening that door, and hence prior to any possible entry to the medical therapy facility.

The intercom provides a means for the prompt exchange of information between medical personnel and the reactor operator (s).

The provision for manual operation of the medical therapy facility's shield door ensures access to any pat; nt in the event of a loss of elecuical power. The presence of the viewing window and a closed-circuit TV camera provide the attending physician and/or medical physicist with the opportunity to monitor the patient visually as well as through the use of various instruments. The viewing window will function even during an electrie power failure because of the provision for emergency lighting.

The specification that the total radiation fluence for a therapy (i.e., the radiation fluences for the sum of all fractions specified in a given treatment plan) not exceed that l

prescribed in the patient treatment plan by 20% establishes an allowable upper limit on the delivered Huence. The 20% criterion is based on the definiticn of misadministration (clause 6-32 SR#-0-91-17 MAR 061992 l

!_,_,_.___.___.._._..u..____.._..__. _.__..___.a._.._._,.-_._.

. l

.- l 4(iv)) as given in 10 CFR 35.2. The criterion that the difference between the administered and piescribed fluence for any seven consecutive days is set at 30% This is also in accordance with the definition of misadministration (clause 4(iii)) as given in 10 CFR 35.2. Finally, if a treatment involves three or fewer fractions, then a more stringent criterien,10%, applies to the difference between the total radiation fluence for a therapy and that F escribed in the treatment plan (10 CFR 35.2(411)). The surveillance requirements for beam calibration checks and characteritations provide a mechanism for ensuring that the medical therapy facility and its bearr will perform as originally designed. Similarly, the surveillance requirements on the beam monitors ensure that these instruments are calibrated by a means traceable to the National Institute of Standards and Technologv. The chambers specified (tissue equivalent, and graphite or magnesium wall) were chosen because they measure dose as opposed to fluence.

'The specification on maintenance and repair of the medical therapy facility ensures l

i that all such activities are perfonned under the supervision of personnct cognizant of quality assurance and other requirements such as radiation safety. The provision on the training ,

and proficiency of non licensed personnel ensures that all such personnel will receive instruction equivalent to that given to licensed reactor operators as regards use of the medical therapy facility beam. (Note Licensed personnel may, of course, operate the medical therapy facility beam.) Also, this provision provides for the posting ofinstructions to be followed in the event of an abnomiality.

The specification on ' recordable events' and 'misadministrations' provides for the documentation and reporting to the U.S. Nuclear Regulatory Commission of improper events regarding the generation and use of the medical therapy facility beam. The requirement' that the Quality Management Program (QMP) be observed  ;

6-33 L S R#-0-91-17 MAR 061992 q

L '

l l

. . _ . ~

ensures that radiation treatnients provided by flie inedical therapy f acility bearn will be adrninistered as directed by an authorized user. (Note: The presence of this corninittment to observe the QMI' in these specifications does not preclude niodifying the QMI' as prosided in that document. Any such inodifications are not considered to be a change to the MITH Techr.ical Specifications.)

6-34 SR#4)-91-17 MAR 061992 1

litfrmn 6.5-1 hilTR Staff, " Safety Analysis Report for the hilt Research Reactor (hilTR ll),"

Report No. hilTNE-115,22 Oct.1970, Section 10.1.3.

6.5-2 Choi, R.J., " Development anti Characterization of an Epithermal 13 cam for lloron Neu'ren Capture Therapy at the hilTR-il Research Reactor," Ph.D. Thesis, Nuclear Engineering Department, hiassachusetts institute of Technology, April 1991.

6-35 S R#-0-91-17 hiAR 061992 4