ML20036B977
| ML20036B977 | |
| Person / Time | |
|---|---|
| Site: | University of Michigan |
| Issue date: | 05/26/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20036B975 | List: |
| References | |
| NUDOCS 9306070431 | |
| Download: ML20036B977 (3) | |
Text
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UNITED STATES 1
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. NUCLEAR REGULATORY COMMISSION-k%, * *. + + f[
WASHINGTON, D.C. 20666
!q SAFETY' EVALUATION BY THE'0FFICE OF NUCLEAR REACTOR REGULATION f
SUPPORTING AMENDMENT NO. 38 T0 FACILITY OPERATING LICENSE N0.' R-28 l
UNIVERSITY OF MICHIGAN DOCKET NO. 50-2 1
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1.0 INTRODUCTION
By letter dated October 29, 1992, as' supplemented on March 1, and. April:15,.
d 1993, the University of Michigan (the licensee) requested that their Technical Specifications (TS) be revised to include changes _ made as a result' ofs a thorough review of the TS. Changes have been made to correct typographical' and spelling errors, to correct section reference numbers, to provide-consistency between sections and to clarify the exact meaning.
The changes made to the TS are denoted in the right margin and are identified byL"38."
2.0 f'iALVATION The significant changes are as follow:
(1)
In TS 3.1.1, the statement "except during the process ofl verifying; j
shutdown margin" has been added. The-purpose of this' change is to allow-i j
the determination of shutdown margin without violating the..TS, since-these parameters may be somewhat off the TS limits when they are being.
determined. The. wording of TS 3.1.1, along with the limitations:en fuel j
movement in TS 3.1.4, give reasonable ass'urance that the licensee will
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make careful-prior estimates of the changes i.n reactivity due.to fuel loading and fuel shuffling so that shutdown margins:will be equal to.
or greater than.025 delta K/K._ However due to the uncertainty in the the reactivity per gram-of fuel in different. locations and~even in the i
same-location due to differences in. surrounding burnups, iteis difficult l
to calculate the shutdown margin for the most reactive shim rod. stuck out.
without a measurement.- These. measurements for. total' shutdown margin and i
the shutdown margin with the most reactive rod stuck'out are made at low power levels under carefully controlled conditions with all rods at.about.
the same position, i.e., the most reactive rod is not withdrawn to its:
outer-limit but it is in the'same position as the other rods. _-The position of these rods at the_ low power critical position,- in conjunction' g*
with other data, then_provides the total shutdown margin, the.shutdownL margin with the most reactive rod stuck _out and.the excess-reactivity of the core.
The staff finds this revision to TS 3.1.1 acceptable.
9306070431 930526
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e <. * (2)
In TS 3.1.3 the statement "except during the process of verifying experiment reactivity" has been added.
The reactivity worth of experiments that have previously been performed are known to a high level of confidence.
For an experiment not previously irradiated, a more detailed review and reactivity evaluation is performed including specific safety review committee approval.
The experiment reactivity therefore, in either case is known to some level of accuracy. Also, the amount of experiment reactivity t. at can be added to a known core configuration is-k also known. This limit will not be exceeded, but actual experiment reactivity may, when measured, be greater than TS 3.1.3 limits.
If.it is, then the experiment (s) will be adjusted to conform to the requirements of TS 3.1.3.
The staff finds this revision to TS 3.1.3.
acceptable.
(3) Specification 3.1.4 has been changed to read "...during fuel movements to.
and from the reactor core." This makes it clear that the reactor must be subcritical by at least 0.025 delta K/K for any fuel insertion into or removal from the reactor core, including during a critical loading experiment.
The way this section was previously written i.e., "...during fuel loading changes" was narrowly interpreted by the licensee to apply only to critical loading experiments and not to regular fuel movements.
This change more explicitly clarifies the intent of the TS. The staff finds this acceptable.
(4)
In Table 3.2, the radiation moniter "6.
Primary Demineralizer" radiation alarm has been deleted.
The intent of the monitor was:
(1) to detect -
fission products from a failed fuel element and (2) to detect radioactive water in the facility's " cold sump" which at one time was pumped directly into the sewer system.
The cold sump connection to the sewer has oeen disconnected, and the sump pumps directly to the facility retention tanks.
From there the water is recycled back to the reactor pool.
The demineralizers never showed any increase in radiation levels as the result of the three failed fuel elements that have occurred at the facility. The mobile air particulate monitors provided immediate indication and longer term confirmation was obtained by pool water analysis.
This has been true at other facilities. The noble gas releases come up into the room and are detected by air particulate monitors and_ the non-gaseous releases get diluted in the water and are not as readily detected. The staff finds that deletion of the Primary Demineralizer radiation alarm is acceptable.
The staff has reviewed the remaining changes as submitted on October _29, 1992, March 1, and April 15, 1993, and finds them acceptable.
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3.0 ENVIRONMENTAL CONSIDERATION
This amendment involves changes in the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20 and changes in inspection and surveillance requirements.
Also, the amendment involves changes in the category of recordkeeping, reporting, and adminis-trative procedures and requirements.
The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and there is no significant increase in individual or cumulative occupational radiation exposure. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9) and (10).
Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.
4.0 CONCLUSION
The staff has concluded, based on the considerations discussed above, that:
(1) because the amendment does not involve a significant increase in the probability or consequences of accidents previously evaluated, or create the possibility of a new or different kind of accident from any accident previously evaluated, and does not involve a significant hazards considera-tion, (2) there is reasonable assurance that the health and safety of the public will not be endangered by the proposed activities, and (3) such activities will be conducted in compliance with the Commission regulations and the issuance of this amendment will not be inimical to the common defense and security or the health and safety of the public.
Principal Contributor:
Theodore S. Michaels Date:
May 26, 1993 4
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