ML19248D704
| ML19248D704 | |
| Person / Time | |
|---|---|
| Site: | Oregon State University |
| Issue date: | 07/20/1979 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Wang C Oregon State University, CORVALLIS, OR |
| References | |
| NUDOCS 7908170223 | |
| Download: ML19248D704 (3) | |
Text
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UNITED STATES g
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NUCLEAR REGULATORY COMMISSION 3
E WASHINGTON D. C. 20555
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July 20,1979 Docket No.: 50-243 Dr. C.11. Wang Reactor Administrater Oregon State University Corvallis, Oregon 97331
Dear Dr. Wang:
On July 5,19/9, our staff discussed your request of April 16,1979, for amendment to the license for the Oregon State TRIGA Reactor with your Mr. Terry Ancerson. During that discussion we requested additional infor-mation. The enclosure to this letter provides the documentation for that request. We request the requested information or a schedule for providing the information within 30 days.
Sincerely, h
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Robert W. Reid, Chief Operating Reactors Branch !4 Division of Operating Reactors
Enclosure:
Request for Aoditional Information 7 9 0 817 07p *;5 7 7 8 3,,,on u
ENCLOSURE REQUEST FOR ADDITIONAL INFORMATION OREGON STATE UNIVERSITY TRIGA REACTOR NEW INSTRUMENTATION Upon review of your submittal of April 16,1979 concerning modifications to the 0.S.T.R. Technical Specifications, several areas are in need of clarification for proposed changes 1 through 4.
Spect fically.
1.
Please document that the new linear " safety power level" channel and the existing percent power channel will use separate ion chambers?
2.
Provide additional supporting infornation and test results or analyses that will support your contention that the new instrumentation package (modification) will be more reliable than the previous system.
3.
Describe the " burn-in" procedures to be used for the new instrumentation.
What criterion will be used to establish an adequate level of reliability?
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4.
Describe the new calibration circuits for linear and log power and period, and discuss test methods employed (a) prior to startup and (b) during operation.
5.
We understand.that, because the fission chamber for the new Linear-Log channel is physically larger than the existing fission chamber, it
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cannot be located in the same position.
Discuss and compare the new fission chamber location to the previous location with regard to source-fuel-detector geometry, including consideration of potential detector shadowing.
Provide a diagram i
indicating the positions of all other proposed instrumentation detectors 4
relative to the source and fuel.
6.
Provide a diagram similar to Fig. 3,16 of the Safety Analysis Report for the 0.5.U. Triga Reactor reflect.ng the new ranges of the proposed channels.
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7.
The letter of April 16,1979 (enclosure 2, page 2, item 8) indicates that the proposed change includes new "pewer supplies, including a j
high voltage supply (Model HV-6)."
For each channel of the existing instrumentation and of the proposed instrumentation, provide a list indicating the detector power supply, loss-of-high-voltage protection (i.e., alarm, scram), and other power supplies.
8.
Describe the new pulsing logic.
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9.
It is our view that the new instrumentation would consist of 3 safety channels instead of the 4 safety channels in your present instrumentation. Please provide your design bases for determining that
.this reduction in the number of safety channels will provide an acceptable degree of protection.
~10.
We understand that by failure of the proposed log-linear channel detector, the linear channel could read low, and consequently cause the control system to automatically start pulling control red (s).
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In such an event, period protection would also be lost.
It appears that in this situation, the new instrumentation does not provide the degree of safety present in the existing instrumentation, where pericd protection would still be available.
Please provide your basis for determining that the proposed instrumentation will provide adequate protection.
11.
For the proposed log-linear channel, will loss-of-high-voltage i.
generate a scram? If so, modify Figure 2 accordingly.
12.
Both Figures 1 and 2 of the proposal show the 1-kw interlock.
Clarify this descrepancy by providing documentation indicating clearly the function point from which the 1-kw interlock is derived.
13.
For the new instrumentation, will an overpover condition, such as i
200% full-power flux at the detector be appropriately accommodated e
by both the detector and the instrumentation without " fold-over?"
Explai n.
14 The existing linear channel trips at a percentage of each range.
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i It is our understanding that the propo:ed safety power level channel
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will only trip at a percentage of full power.
Please provide your i
design bases (or transient analysis) for determining that the new safety power level channel will provide adequate protection.
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