ML20129J415

Application to Amend License R-67,revising Tech Spec Section 6.2.5 to Perform Calibr of Power Channels by Calorimetric or Heat Balance Methods Semiannually.Fee Paid

ML20129J415
Person / Time
Site:	General Atomics
Issue date:	06/04/1985
From:	Mowry W GENERAL ATOMICS (FORMERLY GA TECHNOLOGIES, INC./GENER
To:	Thomas C Office of Nuclear Reactor Regulation
References
67-7063, NUDOCS 8506100082
Download: ML20129J415 (3)

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c .n.- n In Reply Refer To: 67/7063  ;

GA Technologies Inc. l SAN D E UFoRNIA 9211?

(6 t 9) 455-3000 Dr. Cecil 0. Thomas, Chief Standardization & Special Projects Branch Division'of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

Dockt 50-163: R-67; Application for License Amendment and

-Technical Specification Change. (19 copies)

Dear Dr. Thomas:

GA Technologies Inc. (GA) has need to make a change in its subject reac-tor technical specification for reasons stated below. Accordingly we re-quest that our subject license reactor technical spec;fications, Section 6.2.5, be amended to read:

"The reactor power measuring channels shall be calibrated by the calorimetric or heat balance method semiannually but at intervals not to exceed eight (8) months."

Attached.are the fees required to accompany this license amendment request.

The purpose of this request is to seek authorization to perform calibra-tion of the power channels by either_ calorimetric or heat balance methods at least semiannually but with no interval greater than eight (8) months.

This would eliminate need to unnecessarily interrupt the extended runs of the experimental programs for the sole purpose of power channel calibra-tions by the calorimetric method.

For the conduct of extended reactor operations such as for the thermionic tests, certain surveillance tests of the reactor's safety systems normal-ly performed daily are performed on a delayed basis as already provided by the Technical Specifications. See, for example, Section 6.2.4. How-ever, Section 6.2.5 requires that the power measuring channels shall be calibrated at least quarterly by comparing with the heat balance. At present, certain of the thermionic tests would normally exceed three months in duration, but are now required to be terminated because of the requirement to perform a power' calibration (Section 6.2.5).

Not only does this requirement interrupt an otherwise long run, but the thermionic devices are subjected to increased risks. When the reactor is shutdown these devices are subjected to thermal shock. Further, opera-tion of the reactor at intermediate power levels to perform the power 8506100082 850604 i PDR ADOCM 05000163 0%g /k P PDR L, j gd 0

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calibration produces ' intermediate ' temperatures within the devices that

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are .especially risky because of the possibility of fuel migration. ~ It is F

'much gentler on the devices to operate as much as possible at the' design -

temperature.

I- - To' shut [the5 reactor down ' for performing a power calibration (at inter- -

mediate ttemperatures) is therefore doubly risky .for the .thermionic de- -

vices from (1) thermal shock due to temperature changes, and (2) extended Loperation at unsuitable, intermediate temperatures.-

l Justification for increasing the interval from three months to semi-

. . annually:

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1. The Mark III TRIGA reactor license (R-100). authorized extended ther -

& mionic tests =in our San Diego facility. The Technical Specifica-

', tions for that reactor. required only semiannual power calibration and used the wording suggested above.

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2. To instrument for the present continuous operation, we now have ,

, available.a largert number of on-line power indicating monitors, namely:

- 3 CIC chambers with Keithley channels 1 fission counter with Wide Range Channel readout 3 self-power, in-core power monitors

'(3 thermocouple fuel elements are also monitored)

Y With such an array of power monitors, it is very unlikely that all Jchannels could simultaneously fail in such'a fashion as to falsify the true power level. On the contrary, it is clear that any'signifi-Jcant deviation in the reading of one channel will be detected by the-operator and called 'to the attention of the facility management for appropriate' action. Enough channels remain for safe operations.

L, Although we have been required to perform power calibrations only quarterly, we have in the past regularly performed these calibra-

.tions monthly. During the past fifteen years, the longest Mark F O reactor run was on the order of 60 hours6.944444e-4 days <br />0.0167 hours <br />9.920635e-5 weeks <br />2.283e-5 months <br />,.so there was no interfer-4 ence.with a monthly power calibration. The facility management in-tends to continue the monthly power calibrations when there is a return to..the former ' intermittent ~ operating schedule.

3 'The facility management shall continue all the usual. requirements as i set forth in the. facility' written procedures. As an example, a new

. .~ power calibration shall be performed whenever a significant change

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, in core configuration'(fuel or experiments) is made, regardless of

, , wh,en Lthe previous power calibration was made. In addition, the facility management still intends to perform power calibrations monthly should the' operation return to a series of short runs.

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3 s .. s-Cecil Thomas 67-7063

4. An -important incentive for extending the interval between power cali-

.brations (provided no fuel or experiment changes are made) is to pro-tect the thermionic devices. As explained above, every. time the re-actor operation is shut down, the thermionic devices are subjected to undesirable thermal shock and to possible fuel migration should the operation involve extended intermediate temperatures within the devices.

4 GA judges that no safety considerations are altered by this request for

- decreased frequency of power calibrations. All the requirements suggest-ed by good operating practice shall be in effect; therefore, power cali-brations will be made as needed whenever core configuration changes so warrant.. On the other hand, long term operations will not be interrupted solely for power calibrations except for the nominal semiannual tests.

We would appreciate your assistance in expediting this request and look

' forward.to receiving the requested license amendment at your earliest convenience. Should you'have any questions in the matter, please prompt.ly contact by telephone either Dr. W. L. Whittemore at (619) 455-3277 or me (619) 455-2823 Very truly yours.

(

William R. Howry

/ /6 Licensing Administrat r WRM:he

Attachment:

Check for $150

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