ML20113H726
| ML20113H726 | |
| Person / Time | |
|---|---|
| Site: | MIT Nuclear Research Reactor |
| Issue date: | 07/30/1992 |
| From: | MASSACHUSETTS INSTITUTE OF TECHNOLOGY, CAMBRIDGE |
| To: | |
| Shared Package | |
| ML20113H722 | List: |
| References | |
| NUDOCS 9208050212 | |
| Download: ML20113H726 (16) | |
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6.5 Generation of Medical Therapv Facility Beam for Human Therany Applicability This specification applies solely to the generation of the medical therapy facility ocam for the treatment of human patients. It does not apply to any other use of the medical therapy facility and/or its beam.
Objective 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 physician and that the ALARA principle is observed for all non-therapeutic radiation exposures.
Soccification 1.
Patients accepted for treatment shtll 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 Massachusetts Institute of Technology 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 agree that the therapy can be initiated. A certified medical physicist is responsible for monitoring 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 j
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"4 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 consecutive 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 automatic dly upon opening of the medical therapy facility's shield door.
(c)
The shutters that control beam delivery shall be designed to close automatically upon failure of electric power or on low air pressure if the shutter is operated pneumatically.
(d)
Shutters that control beam delivery and that are nomnlly pneumatically-operated shall, in addition, he designed for manual closure.
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 control 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 position verification is limited to seven consecutive working days.
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.
6-22 SR #-0-91-17 MAR 061992
(a)
This radiation 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 souac ~ithin 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.
(c)
This radiation monitor shall be calibrated quarterly.
(d)
The audible alarm shall be set so as to alert personnel if radiath levels in the medical therapy facility exceed that which exists with the reactor at full power and with the shutters that control beam delivery in the closed position by more than a factor of three. This monitor and/or its alarm may be 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 r:edical therapy facility's shield door.
(c)
In the event that this monitor is ir aperable, personnel entering the medical therapy facility shall use either portable survey instruments 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 protectic program. Use of these instruments / dosimeters as a temporary means of satisfying this provision is limited to seven consecutive working days.
8.
An intercom or other means of two-way communication shall be operable between the medical therapy facility and the reactor control room.
6-23 SR#-0 91-17 MAR 061992
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 pon 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 fail during the irradiation, the treatment may be continued at the discretion of either the patient's physician or medical physicist. Adequate lighting to pemiit such viewing shall be assured by the provision of emerger 'y lighting.
11.
The total radiation fluence delivered by the medical therapy facility beam as measured by on-i'ne beam monitors shall not exceed taat prescribed in the patient treatment plan by more than 20% The treatment is normally delivered in fractions
.n 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 consecutive days).
Finally, if the treatment consists of three or fewer fractions, 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:
Interlock or Channel Surveillance a)
Medical therapy facility minor scram Scram test b)
Shutters will not open unless Operational test shield door is closed c)
Shutters close upon both manual and Operational test automatic opening of shield door 6-24 SR#-0 17 MAR 061992
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Shutters close on loss of electrical Operational test power and/or reduction of pressure hi pneumatic operators e)
Manual closure of pneumatic shutters Operational
- cst f)
Beam-monitoring instrumentation Functionalcheck g)
Shutter status lights Functional check h)
Radiation monitor alarm Operational test 1)
Radiation monitor and/or alarm Functional check enabled upon opening of shleid 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.
4 14.
The medical therapy facility beam shall be characterized dosimetrically prior to the initiation of patient irradiations. Similarly, a characterization shall be performed prior to patient irradiations following design modifications to the beam. In the event that components of a given design are replaced as opposed to modified, then a calibation check as opposed to characterization shall be performed. Calibration checks of the beam shall be made at least weekly for any week that the beam will be used for human therapy. The weekly calibraticn check shall be made prior to any patient irradiation for that week. A beam characterization shall have been done not less than six months prior to any patient irradiation.
15.
Maintenance, repair, and modification of the medical therapy facility shall be perfonned 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 6-25 SR#-0-91 -17 MAR 061992
' medical therapy facility' includes the beam, beam shutters, beam monitoring equipmer.t, medical therapy facility thielding, shield door, and patient viewing equipment.
All modifications will be reviewed pursuant to the requirements of 10 CFR 50.59. The operating couch, patient positioning equipment, medical instruments, 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 hilt Research Reactor but who are responsible for either the medical therapy or the beam's design including construction and/or modiGcation 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)
Instructions 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 turning tne 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 abnormal condition occurs. A directive shall be included with these instructions to notify the reactor console operator in the event of any abnormality.
(c)
In the event that a shutter affects reactivity (e.g., the D 0 shutter),
2 personnel who are not licensed on the hilt Research Reactor but who have been trained under this provision may operate that shutter provided that 6-26 SR#-0-91-17 hiAR 061992 i
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verba; pennission is requested and received from the reacter console operator imt 'htely 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 acconlance with the MIT Research Reactor's training program or at least for three years. A list of personnel so qualified shall be maintained in the reactor control 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 of this sper.fication shall be reported to the U.S. Nuclear Regulatory Commission ('4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> verbal,15 day written repon).
The -24 hour _ verbal reper!s n ill be made to the Regional Administrator, Region I, or his designate.
The 15 day written reports will be sent to the NRC Doenment Control Desk with a copy to the Regional Administrator, Region i. or his designate.
l 18.
The requirements of the Quality Management Program for the 1
Generation of Medical Therapy Facility licam for lluman Therapy at the Massachusetts Institute of Technology Research Reactor shall be observed for any human therapy.
19.
The. bean monitors which are described in provision 11 of this technical specification shall be calibrated against instrument < that measure dose including a tissue equivalent chamber and a graphite or magnesium wall lonization chamber (or the equivalent to any of these three) that have in turn been calibrated by a secondary calibration laboratory.
The _ calibration of these monitors shall be done prior (within six months) to the initiation of patient irradiations and every 6-21 SR#-0 ?! 17 MAR 061992
-. -. i
two years thereafter. In addition, the proper operation of these beam monitors shall be verified af, part of the beam characterization process that is done seml. annually as described in provlsion 14 of this technical specification.
20.
It shall be possible to close the shutters that control beam delivery from within the medical therapy facility.
This capability shcIl be verlfled fer proper operation at least monthly and prior to the treatment of human patients if the Interlock has bean repaired or deenergized.
De nitions n
1.-
The medical therapy facility is equipped vehh shutters that are used (i) to control beam deliver and (ii) to adjust the neutron energy spectrum of the beam. The j
former currently include lead, boral, and light water shutters as described in Reference 6.5 :. The heavy water blister tank, which is also described in Reference 6.51, is an example of the latter. It is conceivable that these designations may change should it be found desirabic to alter the beam configuration. Accordingly, the phrase " shutters that control b:am delivery" refers either to the aforementioned three existing shutters or to any future shutter or group thereof that provides an equivalen* or greater reduction in beam inw.;;ity.
Shutter-effect analyses shall be docomented through the standard safety review process including, where appropriate, an SAR revision and submission to NRC under 10 CFR 50.59, 2.
The functional check listed as the surveillance requirement for the beam-monitoring instrumentation shall consist of verifying that the system output is consistent-(i 10%) with pn:viously measured values upon nomulization to a common reactor neutronic power level.
6-28 SR#-0-91-17 MAR % 1992
3.
The tenn ' characterization' refers to the process of obtaining the dose versus-depth profile in phantoms as described in Reference 6.5 2 or an equivalent process. The dose versus depth profile from the surface of the phantom to a depth at least equivalent to the total thickr.ess of the body part to be treated oss a central axis is deemed adequate for a characterization. Fatt neutmn, thennal neutron, and gamma ray components are detennined in a full characterization and monitors are normalized by this characterization.
4.
'Ihe tenn ' calibration check' refers to the process of checking the k,- tm intensity and quality via one or more of the following: foil activation; use of a fissinn chamber, use of an ion chamber, or an equivalent pmcess. The purpose of a calibration check L
is to ensure that the beam has not chtmged in a significant way (e.g., energy 1
l spectum or intensity) from the beam that was characterized.
5.
The tem 1' design modilk..lon' as applied to tha. medical therapy facility beam refers (a) to a change that is shown to alter the dose versus depth profile of the fas' neutrons, thennal neutrons, or gamnu rays in the beam as sensed by the calibration check and- (b) to a change - that has the potential to increase significantly the amount of activation products in the medical therapy 1
facility when the beam is to be used for the treatment of human paticats.
L 6.
The tenn ' radiation lluence' means the total fluence of neutrons and gamma L
radiation that is emitted in the medical therapy facility beam. 'ihe determination of the ratios of gamma, fast neutmn, and thennal neutron fluences is part of the beam 1
characterization. Knowledge of these ratios al%ws the total radiation fluence to lx:
monitored by the on-line detectors, which am neutron sensitive. Compliance with the !!mits speciiled on radiation fluence by this specification is detennined by reference to the fluence monitored by these detectors.
6-29 SR#491-17 MAR 061992
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'Ihe tern ' recordable event' means the administration of:
(a)
A radiation treatment without a written directive where a written directive is
. required and where the treatment is appropriate; or (b)
A emdhti u neatment where a written directive is required without the per treatment recording of administered radiathm Duence in the appropriate record; or (c)
A treatment delivery for which the administered radiation Duence for any
- given fraction is 15% greater than prescriled.
8.
The tenn ' misadministration' means the administration of a radiation therapy:
(a)-
Involving the wrong patient, wrong mode of treatment, or wrong treatment sitt or -
(b)
When the treatment delivery is not in accordance with provision 11 of this specification, 9.
' The term ' 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 2nd which specifies treatment site, the total radiation fluence, radiation nuence per fraction, and overall treatment pericxi.
10.
The term ' human therapy' means radiation treatments that are of direct therapeutic benefit to the patient and/or part of investigatoy studies that involve hunans.
I1.
The tenn ' certified medical physicist' means a medical physicist certified in either radiological physics or therapeutic radiation physics by the American Board of Radiology, or in therapeutic radiation physics by the American Bcard of Medical Physics.
11 MIS 1he 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 6-30 SR#-0 91-17 MAR 061992
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NitC to rc..ize the hilt llescarch iteactor's hiedical Therapy I acility beam for human therapy, enstnes that medical criteria imposed by NRC on such licensees for the use of the MIT ltesean h Itcactor's medical therapy facility beam for human therapy will be fulfilled.
He second provision delineates the division of ruponsibilities between the hiassachusetts Institutc of Technology and the medical licensee that refers the patient. Also, it establishes administrative authority and pmtocol for initiating and tenninating a radiation therapy.
The requirement that it be possible to initiate a minor scram from a control panel located in the medical therapy facility area assures the attending physician and/or medical physicist of the capabihty to tenninate the treatment immediately should the need arise. The provision that access to the medical therapy facility be limited to a single door ensures that there will be no inadvenent entrier. The various interlocks for the shutters that control beam delivery ensure that exposure levels in the medical therapy facility will be minimal prior to entry by personnel who are attending the patient. The shutter-indication lights serve to noilfy 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 ta 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 distrnet attending personnel. The monitor and/or its alcrm are interlocked with the shleid 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 promp'. exchange of information between medical personnel and the tractor operator (s).
6-31 Sit #491-17 MAR 061992
7 The pmvision for manual operation of the inedical therapy facility's shield door ensures access to any patient in the event of a loss cf electrical power. The presence of the viewing window and a closed circuit TV camera provide the attending physician and/or medical physicist with the opponunity to monitor the patient visually as well as through the use of various instruments. The viewing window will function even during an electric power failure because of the provision for emergency lighting.
The specification that the total radiation Huence for a therapy (i.e., the radiation fluences for the sum of all fractions specined in a given treatment plan) not exceed that prescribed in the patient treatment plan by 20% establishes an allowable upper limit on the
)
delivered Huence. The 20% criterion is based on the dennition of misadministration (clause j
4(iv)) as given in 10 CFR 35.2. The criterion that the difference between the ndministered and prescribed 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 'Sree or fewer fracilons, then a more stringent criterion,10%, applies to the difference between the total radiation fluence for a therapy and that prescribed in the treatment plan (10 CFR 35.2(411)). The various surveillance requirements as well as those for beam characterization and/or calibration checks provide a mechanism for ensuring that the medical therapy facility and its beam will perfonn as originally designed.
Ihe specification on maintenance and repair of the medical therapy facility ensures that all such activities are performed under the supervision of ersonnel cognizant of quality assurance and other requirements such as radiation safety. The provision on the training and pronciency 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 6-32 SR# 0-91-17 MAR 061992
k s
a, medical therapy facility beam.) Also, this pruvision pmvides for the posting ofinstructiom.
to be followed in the event of an abnonnalhy.
The mecification on ' recordable events' and 'misadministrations' provides for the documentation and reporting to the U.S. Nuclear Regulatory Commission of improper events regarding the generation und use of the medical therapy facility beam. The requirement that the Quality hinnagement l'rogram (Qh11') be obsca red ensures that radiation treatments provided by the medical therapy facility beam will be administered as directed by an authorized user. (Nute.: The presence of this committment to observe the Qh11' In these technical specifications does not preclude modifying the Qh11' as provided in that document..Any such modifications are not considered to be a change to the h11TR Technical Specifications.)
The specification concerning the beam monitors ensures that these l
instruments are calibrated by a means traceable to the National Institut? of l
Stand.irds and Technology. The chambers specified (tissue equivalent, and graphite or magnesium wall) were chosen because they measure dose as t
opposed to Iluence.
The provision that it be possible to close the shutters that control beam delivery from within the medical therapy facility provides an additional mecsure of safety for these individuals who will be attending a patient during therapy.
Specillcally, should anyone not be clear of the medical therapy facility prior to the initit. tion of a treatment, that person can prevent his or her being exposed to elevated radiation levels.
6-33 SR# 0 91 17 htAR 061992 e
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.t Refereners 6.5-1 hil'IR Staff, " Safety Analysis Report for the hilt Research Reactor (MITR il),"
Report No. MITNil 115,22 Oct.1970, Section 10.1.3.
6.5 2 Chol, RJ.," Development and Characterization of an !!pithennal lleam for lloron Neutron Capture Therapy at the MITR.il Research Reactor," Ph.D. Thesis.
Nuclear !!ngineering Department, Massachusetts Institute of Technology, April 1991.
.i.
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6-34
- SR#4)-9l 17 MAR 061992
F.
Modification to' Existing Technical Specification #7.13.5 on l
Reporting Requirements i
1
..o (ii)
Gaseous Waste (Summarized on a monthly basis)
(a) 1(adioactivity discharged during the reporting period (in curies) for:
(1)
Gases (2)
Particulates, with half lives greater than right days.
(b)
The MPC used and the estimated activity (in curies)
I discharged during the reporting period, by nuclide, based on representative isotopic analysis.
(iii)
Solid Wage (a)
He total amount of solid waste packaged (in cubic fut),
l (b) ne total activity and type of activity involved (in curies).
(c)
The dates of shipment and disposition (if shipped offsite),
l.
A summary of the use of the medical therapy facility for human therapy.
(1)
Investigative Studies (a)
Nature and status of the siudies.
(b)
Number of patients involved.
(11) llumnn 1 hernny
-(a)
Number of patients treated.
(b)
Type of cancer treated.
7-32
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