ML20217N747
| ML20217N747 | |
| Person / Time | |
|---|---|
| Site: | Kansas State University |
| Issue date: | 10/18/1999 |
| From: | Sharp S, Jacqueline Thompson KANSAS STATE UNIV., MANHATTAN, KS |
| To: | Michaels T NRC (Affiliation Not Assigned) |
| References | |
| NUDOCS 9910290121 | |
| Download: ML20217N747 (2) | |
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I STR1E 18 October 1999 g g g4 Department of Mechanical and Nuclear Engineering
. 302 Rathbone Holl U. S. Nuclear Regulatory Comm.ission uansa,,an.Ks 665o6-5205 Attn: Theodore Michaels 785-532 56io ron: 7ss.532 7057 Oflice of Nuclear Reactor Regulation Mail Stop 1IB20 Washington, DC 20555-0001 Re: License R-88, Docket 50-188 This is to report a violation of the Technical Specifications for the Kansas State University TRIGA Reactor Facility, namely, overpower operation as the result of a malfimetion in our percent power channel. This letter describes the problem, our discovery of the malfunction, repairs made, and changes in our maintenance plan that will prevent a reoccurrence.
On 23 September 1999, we began to perform a power calibration of our instrumentation. ;
This calibration is required by our Technical Specifications on an annual basis. We J found a measured power of 260.9 i 0.2 kW, but an indicated power of 250 kW.
Technical specifications limit operation to "0.25 megawatts nominal,0.2.6 megawatts upper limit." At this point I contacted Ted Michaels at the NRC with a notification about the problem, as well as the indication that the calibration would be re-performed.
On 27 September, the repeat power calibration was done. It resulted in a measured power of236.0 0.3 kW for an indicated power of 225 kW. This would translate to a true power of 262.2 kW with an indicated power of 250 kW. This confirmed a violation of our Technical Specification limit.
At this time I again called Ted Michaels with the results of the power calibration, and also advised that we would repair the channel and then recalibrate power indicators. I also indicated that this repon would follow within the next thiny days.
By 7 October, the channel was repaired and returned to service for the purpose of another power calibration and testing. It was found that the errors in indicated power were due to /
a failure in the calibration of the channel. On 8 October, power calibration revealed that O the power channel read consistent with measured power, and SCRAMS were tested, satisfying the functional performance test. The channel was returned to service.
Since this time we have encountered no problems with the percent power channel. Its g power indications are always consistent with the linear channel, and it is functioning 0 normally.
At this point, I would like to enumerate the steps that the reactor staff will take to prevent any such occurrence from happening again. First of all, we have added to our internal
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9910290121 9(1018 PDR ADOCK 05000188 S PDR
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. I maintenance list a requirement to check the power channel against its calibration currents
- on.a semi annual basis. Secondly, whenever a problem is suspected with the indication or circuitry in the power channel,- .ve will check not only the calibration currents, but also-the internal test points.
These steps should prevent any reoccurrence of power indication problems, and the reactor instrumentation is now functioning normally both in steady state and pulsed operation. Should there be any ' questions about this report or the behavior of the
' instrumentation, I can be contacted at either (785) 532-6657 or by email at siss362/a.ksasdu. The Reactor Manager, J. Garth Thompson, can be reached by telephone at (785) 532-2600, or by email at ,igtemne.ksu.edu.
i Sincerel ,
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Steph nie Sharp, et r Supervisor KSU Nuclear Reactor Facility for:
0 f $d6 J Garth Thompson, Reactor Manager KSU Nuclear Reactor Facility l
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