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,'"..L August 8, 1973 jff ru e
l Mr. Norman C. Moseley, Director Directorate of Regulatory Operations U. S. Atomic Energy Commission Region II - Suite 818 r
230 Peachtree Street, NW.
Atlanta, Georgia 30303
Dear Mr. Moseley:
I This is a further response regarding commitments made in I
our letter of June 25, 1973, from R. T. Hathcote to your office. Our resolution of those commitments is described in the enclosure to this letter. We hope these, resolutions will be satisfactory.
i Very truly yours,
/s/ J. E. Gilleland t
1 J. E. Gilleland Assistant to the Manager of Power
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Enclosure
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8604300434 860317 PDR FOIA Attachment B MORROW 85-782 PDR C0PY
ENCLOSURE RESOLUTION OF C0}9fIIMENTS MADE IN TVA LETTER OF JUNF. 25, 1973 In our letter of June 25, 1973, TVA made commitments in regard to four last-minute licensing concerns. We have completed the necessary modifications and additional tests to meet these commitments as follows:
A.
Door Closers - As originally installed, the negative pressure inside the buildir.g was sufficient to prevent the door closers from completely closing and latching some of the' doors in two sets of personnel airlocks when the SGTS was operating. The opening direction of two doors in one set and of one door in the other set has been reversed so that the negative pressure will assist the closing motion.
Following completion of the work to reverse the opening direction of the doors discussed above, a secondary containment surveillance test was conducted. The test resulted in a building vacuum that was greater than 1/4 inch water gauge with a SGTS flow rate (in one train) of less than 9000 scfm. These results demonstrated secondary containment integrity was maintained.
B.
Containment Inerting - The broken dip tube in the liquid nitrogen storage tank has been replaced with the modified design as discussed in the above referenced letter. The preoperational test, TVA-6B-Primary Containment Atmospheric Control (Inerting System), has,been completed and the results are being reviewed by DED.
There are five exceptions noted; three of which are associated with the purge subsystem of the inerting system and, therefore, they are not related t'o the use of the inerting system as an
. interim CAD system.
(The purge subsystem is used to expedite inerting the containment from a deinerted state.) The fourth exception concerns an incorrectly sized orifice in a flow element which will be resized and this portion of the test repeated.
As sized, the flow meter read 100 percent with a nitrogen flow rate of 41 scfm and the flow control valve (FCV) at 70 percent of full opening. A conservative extrapolation of the FCV opening versus nitrogen flow rate in scfm indicates that 50 sefm will be obtained at less than an 85 percent FCV opening. Thus, we are confident that the system will deliver 50 scfm when used in the interim CAD mode.
A repeat of the test will confirm that the instrumentation problems h* ave been corrected.
The fifth exception concerns inleakage to the vacuum jacket and, as a consequence, we have excessive boiloff of liquid nitrogen.
The source of inleakage has been traced to two possible problems. One possibility is leakage through attached instrumentation (Hastings Vacuum gauge), and the other could be the result-of a TVA connected vacuum pump loading to oil contamination of the insulation.
Tests at the manufacturer's plant following the repair of the dip tube indicated that the vacuum jacket was sound. A mass spectrometer indicated no inleakage from either the tank or the outer shell when the most sensitive scale was used.
In addition, the tank was loaded with liquid nitrogen, and,a three-day test was conducted for inleakage. This test met the manufacturer's guarantee of a pressure rise of less than 120 micron of Hg per year.
Thus, the tank integrity was established at the factory.
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The tank was emptied of liquid nitrogen and shipped with the jacket
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evacuated. The initial vacuum was less than 25 microns of Hg, and when it was measured at the site 7 days later, it was 50 microns of Hg.
This factor of two increase is attributed to heating up from a liquid nitrogen temperature of -238.8 F to an atmospheric temperature of about 85 F with essentially no inleakage.
We will continue to investigate the two possible sources of inleakage described above.
If the inleakage is not corrected before we exceed, one (1) percent of rate power, we will attach a vacuum pump and maintain the required vacuum until the probicm is resolved.
The pump would be powered from the same power source as presently provided for the tank controls. Therefore, we feel that we have met our commitment for completing the containment inerting preoperational test made in item B of the above referenced letter.
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. C.
Heating and Ventilation - The actual flow rates and distributions for the reactor building and control bay have been analyzed, and the results of such analyses are described below:
1.
Reactor Building - New sheaves were provided for the exhaust fans.
contrary to the expectation expressed in item C.(1) of our June 25 letter, the installation of new sheaves and subsequent rebalancing increased the pressure drop sufficiently so that the total flow rate was not increased appreciably.
However, sufficient total flow was available to properly distribute the flow to all local areas.
In addition, some leakage paths had to be plugged to increase the differential pressure between some local areas.
The results of this work have been reviewed by our Division of Engineering Design (DED) taking into consideration flow rates, temperatures, and differential pressures. As a result of that review and an analysis of predicted heat load, DED has concluded that the present system is satisfactory for full power operation.
In addition, new drives (sheaves and motors) for the exhaust fans have been ordered, and they will be installed during the first refueling outage. A flow distribution check will be made to assure that with these new drives in service, additional margins will be provided for all flow rates.
I Steps are being taken to confirm that adequate flow and temperature control has been achieved during normal operation. This will assure that ne degradation occurs as a result of the slightly less than design flows.
. 2.
Control Bay - Rebalancing has been completed to increase the flow to some local areas, and the results of this new flow distribution have been reviewed by DED. The review still indicates that the air tem-perature increase across two of the electrical board rooms will be 2 F higher than was desired. However, as reported in item C.(2) of our June 25 letter, our experience at our fossil plants indicates that this equipment will operate for years under such con-ditions without observable degradatio'n.
In addition, the review indicates that for operator comfort it may be desirable to limit,the Unit 2 equipment that is energized at any one time in the common control room for Units 1 and 2.
The Unit 3 preoperational test has proven conclusively that the control bay cooling system is completely adequate for Unit 1 operation.
New tests are being performed to determine precisely the chilled water system cooling capacity, the coil capacities, and the air heat balance for the Unit 1, 2, and 3 control rooms.
The data from these tests will be used to determine if modifications are necessary for 2 unit or 3 unit operation.
In order to provide additional margin, we have ordered replacement drives (motors and sheaves) for Unit 1 and 2 shutdown board room exhaust fans.
In addition, we will replace the Unit 1 shutdown board room supply fan with a heavier duty unit (withstand higher differential i
pressures). This new equipment will be installed before the first refueling outage.
. D.
TIP - A final deficiency report was filed with the Directorate of Regulatory Operations on July 9,1973, that described this problem with the pressure-sensitive limit switch in the TIP system and the necessary modifications for correcting the deficiency.
As stated in the report, a temporary solution of milling slots in the actuator plunger to provide pressure equalization has already been made and satisfactorily tested for Unit 1.
The TIP system will achieve all of its design objectives with the temporary modification without increasing the risk to the health and safety of the public.
As a permanent solution, a proximity-type limit switch will be installed as soon as it is available at the site.
We conclude that we have sufficiently cleared up these outstanding matters so that any remaining work on these four items can be included on the list of Unit 1 exceptions that are deferred until after Unit 1 operation.
Therefore we request that the necessary actions be taken to allow removal of the restriction on our license, which temporarily limits activities to fuel loading, low power testing, and operation at one (1) percent of the rated power level, i
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c, REGION II FEEDER INSPECTION REPORT IDENTIFICATION SHEET REPORT NO.
TO:
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7 Licensee:
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Inspection Dates
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Other Inspectors
+? d-Feeder Report Prepared By:
Date Inspector's Evaluation (continue on attached sheet, if necessary)
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-,Signprn"
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The attached Feeder Inspection Docu:tentation is transmitted in reviewed and approved form.
4 Coments:
. Signature Date
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