ML20046A033
| ML20046A033 | |
| Person / Time | |
|---|---|
| Site: | Kansas State University |
| Issue date: | 07/14/1993 |
| From: | Faw R KANSAS STATE UNIV., MANHATTAN, KS |
| To: | Michaels T NRC |
| References | |
| NUDOCS 9307230365 | |
| Download: ML20046A033 (2) | |
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Departrnent of Nuclear Engineering Ward Hall SM unrvertstry Manhattan, Kansas 66506-2503 913 532 5624 14 July 1993 Mr. Theodore S. Michaels U.S. Nuclear Regulatory Commission ONDD M.S. I l-B-20 Washington, D.C. 20555 Re: License R-88, Docket 50-188
Dear Mr. Michaels:
This is a request for a change in wording in the technical specifications for the operating license of the Kansas State University TRIGA Mk-II Nuclear Reactor. Table II, Item 2, in the Technical Specifications (Appendix A of .
the license) requires an interlock, which, in the steady-state mode of operation, prevents
" application of air to transient rod unless regulating and shim rods are fully inserted."
It is requested that item 2 be reworded, to require an interlock, which, in the steady-state mode of operation, prevents
" application of air to transient rod unless the transient-rod shock absorber is in the fully down position."
It is also requested that we be permitted to operate the reactor pending resolution of this change in technical specifications.
Background Information In the steady-state mode of operation, the transient (pulse) rod operates as follows: A shock absorber, located on the bridge above the reactor tank, is moved vertically, by motor, to a fully down position. Compressed air is
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applied to hold a piston, connected to the control rod, in contact with the shock absorber. When the shock absorber is down, application of air does t not move the rod and there is no reactivity effect. The shock absorber is then moved upward, by motor, thus moving the control rod itself to some 220040 n i v O 9307230365 930714 9 pc PDR ADOCK 05000188 b p PDR [ ]
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U.S. Nuclear Regulatory Commission,14 July 1993 Page 2 position determined by the reactor operator. Other control rods are then positioned to achieve operating conditions determined by the reactor operator. Once air is applied to the transient rod, that rod, and the reg and shim rods, operate independently.
The specification dates from 1962, when the shock absorber was moved into position .
manually and left continuously in a (usually) fully up position. The interlock specification prevented the reactor being pulsed, i.e., transient rod pneumatically ejected, in the steady-state mode of operation. Some years ago, the shock absorber for the transient rod was motorized so that its use is as described above.
We are now in the process of installing an operating console that saw' previous service with the U.S. Geological Survey TRIGA Reactor in Denver. This console has a slightly different interlock arrangement, which was not discovered until installation was in process. In the steady state mode of operation, compressed air may not be applied to the transient rod unless the shock absorber is in the fully down position.
Thus, as with the origiral console, the interlock prevents the reactor from being pulsed in the steady state mode of operation Safeguards Committee Action This request has been approved by the Reactor Safeguards Committee for the TRIGA Reactor. They agree that the new console meets all technical specifications for the reactor, but that an editorial change is needed to clarify the specification for an interlock on application of air to the transient rod. .,
Sincerely,
'g Richard E. Faw, Director KSU Nuclear Reactor Facility Phone 913-532-5963, FAX 913-532-6952 i
cc: U.S. Nuclear Regulatory Commission, Region IV Reactor Safeguards Committee
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