ML20114D701

Forwards Mod to Response to Request for Addl Info Re Mitr TS 6.5, Generation of Medical Therapy Facility Beam for Human Therapy. Proposes Rev to Second Sentence of Provision 19 on Pages 6-27 & 6-28 to Read as Listed

ML20114D701
Person / Time
Site:	MIT Nuclear Research Reactor
Issue date:	08/31/1992
From:	Bernard J MASSACHUSETTS INSTITUTE OF TECHNOLOGY, CAMBRIDGE
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
TAC-M82958, NUDOCS 9209090265
Download: ML20114D701 (4)

Text

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NUCLEAR REACTOR LABORATORY

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L e.Q AN INTERDEPARTMENTAL OENTER OF MASSACHUSET I S INSIll .lTE OF TECHNOi OGN, I

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j; f O K. HARUNG 133 Albany Speet. Cambrdge, Mass. 02139' J A. BERNARD. JR

j. O, rector Tetetai No 1617)253 7300 _ Director of 4eactor operatons l Teier No 921473 MIT-CAM

, Tet No. (617)253 4202 i

August 31,1992 i

U.S. Nuclear Regulatory Commission -

A'lTN: Docunent Control Desk -

I Washington, D.C. 20555 L -

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Subject:

Modification to Response to Request for Additional Information (TAC No. M82958)  :

l Concerning Generation of Medical Therapy Facility Beam for Human Herapy,

License No. R-37, Docket No. 50-20 i

! Gentlemen:-

On 07/30/92, the Massachusetts Institute of Techno?ogy submitted a revised version of

. proposed MITR Technical Specification No. 6.$, " Generation of Medical Therapy Facility Et am L for Hunun Therapy." nat revision waslsubmuted in response to the U.S.1 Nuclear . Regulatory:

Commission't request for additional information'(TAC No. ;M82958). _ MIT has conducted.a -

j further roiew of the materialin the proposed technical specification and . feels that,.as now ' worded, . ,

, provision #19 is impracticel. Pmvision #19 specifies that a secondary calibration laboratory shall _

calibrate the instruments that are used to calibrate the beam monitors. 31oreover, it requires that "The calibration of these monitors shall be done prior (within six months) to the initiation of patient irradiations and every two years l thereafter." - There are fonly i few secondary . calibration laboratories that do mixed-field dosimetry. Accordingly, additional flexibility is needed. -It is therefore proposed to revise the secono sentence of provision #19 on pages 6-27 and 6-28 to read, ,

"%e calibration of these monitors shall be done prior to the initiation of patient irradiations 'and

every two years thereafter."

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. _ nis abovc pioposed- calibration frequency 10 in agn:ement withithat: required for .

, teletherapy. Also,- it should be noted that other calibrations / checks are done. The schedule is:

i Is:sl- Frecuency Provision 3

I Calibration Check Weekly - 1 Characterization: Semi-Annually 14

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l Secowlary Calibradon Every Two Years 19 f

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. U.S. Nuclear Regulatory Comm ission Page 2 4

j Enclosed please find revised copies of pages 6 27 and 6-28 of the proposed specification.

! His change has been reviewed and approved by the MIT Reactor Safeguards Committee.

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Sincerely,

',A ct A-

! John A. Bernard, Ph.D.

Director of Tieactor Operations MIT Research Reactor -

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! JAB /gw i

Enclosures:

Revision to Proposed MITR TS #6.5 (pp. 6-27 & 6-28) cc: MITRSC (with enclosures)

. USNRC - Project Manager, NRR/PDNP USNRC - RegionI Chief, Effluent PMiation Protectien Section FJtPS)

FRSSB/DRSS USNRC - Director.

NRR/PDNP i

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verbal permission is requested and received from the reactor console operator immediately prior to such action. Emergency closures are an exception and may be made without finit requesting permission.

Reconis of the training provided under subparagraph (a) above shall be retained in accordar a 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 teactor 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 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 I, or his designata. 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 Generation of Medical Therapy Faci!ity Beam for IIumut Therapy at the Massachusetts Institute of Technology Research Reactor shall be observed for any human therapy.

19. The beam monitors which are described in provision 11 of this technical specification shall be calibrated against mstruments 'that measure dose including a tissue equivalent chamber and a graphite or magnesium wall ionization 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 to the initiation of patient irradiations and every two years thereafter.

6-27 SR#-0-91-17 MAR % 1992 1

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. In addition, the proper operation of these beam-monitors shall be verified as part _of- the beam characteri7ation process that is.done semi annually as described in provision 14 ' of this technical-specification. _,

l 20. It shall be possible to close the shutters'that control beam delivery '

l from within the medical therapy facility. This capability shall ~ be-l Verified for proper operation fat least-- monthly _ and - prior to_- the-l l treatment of human patients if the. Interlock has been repaired or .

j deenergized.

{- Definitions

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

beam delivery and (ii) to adjust the neutron energy spectrum of the beam. The -

former currently include lead, boral, and light _ water shutters 'as described in. -

Reference 6.5-1. The heavy water blister tank, which is also described in t

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

j configuration. Accordingly, the phrase " shutters that control beam delivery".refus

either to the aforeme.

tioned three existing shutters or to any future shutter or group thereof that_ provides an equivalent or._ greater reduction ~in beam intensity.

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! Shutter-effect analyses shall be documented through the standard safety review

i. process including, where appropriate, an SAR~ revision and submission to NRC i

i under 10 CFR 50.59.  ;

l 2. The functional check listed as the surveillance requiremert for the beam-monitoring i

. instrumentation shall consist.of verifying that the system output is consistent 2

( 10%) with previou.dy measured values upon normalization to a common reacto-neutronic power level.

6 l SR#4)-91-17 MAR 061992

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