ML19339B944
| ML19339B944 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 11/05/1980 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8011100474 | |
| Download: ML19339B944 (2) | |
Text
TENNESSEE VALLEY AUTHORITY CH ATTANOOG A TENN EGSEE 37401
- . n,w 400 Chestnut Street Tower II
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November 5, 1980
':J) m' 10 /c1 9 15
'Z i h SERVICES Mr. Harold R. Lenton, Director Office of Nuclear Reactor Regulation U.S. Nucicar Reculatory Connission Washington, DC 20555
Dear Hr. Denten:
In the Matter of
)
Docket No. 50-327 Tennessee Valley Authority
)
Pursuant to Section 1.C.(3) of the Sequoynh Nuclear P2 ant Unit 1 License No. LPR-77, TVA requests your concurrence in a change to the startup test progran eequence. The proposed change in the test program sequence does not affect the basis for the safety analyses of the startup test program.
Enclosed are the juatifications for the proposed chango from the startup test sequence shown in Table 14.13 of the Final Safety Analysis Ecport.
All three tests, W 10.2, SU 1.1, and SU 1.2, will be conpleted before reaching the 100 percent test plateau of the startup test program cur-rently scheduled before Novecber 30, 1980.
The Sequoyah Nuclear Safety Review Board has concurred in the proposed change to the startup test program as described in the enclosure.
Very truly yours, TENNESSEE VALLEY AUTHORITY
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L. M. Mills, 'anager Nuclear Regulation and Safety Sworn t and subscri ed befero tre thisd day of hw 1980 uM L Ol.$hlld Notary Public My Cor=ission Expires
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8011100
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ENCLOSURE SEQUOYAH NUCLEAR PLANT JUSTIFICATIONS FOR CHANGE TO STARTUP TEST SEQUENCE The following is justification for proposed changes in the sequence of j
startup tests shown in Table 14.1.3 of the Sequoyah Nuclear Plant FSAR.
i All tests will be conducted at the power levels indicated in the FSAR.
l This change would involve three tests: W 10.2
" Steam Generator Level Control," SU 1.1
" Loss of Offsite Power," and SU 1.2
" Shutdown from Outside the Control Room." A discussion of the requested change for each of these tests is presented below.
W 10.2
" Steam Generator Level Control" involves the calibration of I
control system settings for the automatic control of steam generator 1evels. We request that this test be performed upon recovery from the negative rate trip performed at 50 percent power. Following this trip, the steam flow transmitters (which are a part of the automatic level control system) are to be replaced. Therefore, in order to eliminate an unnecessary repetition of this test, we propose to postpone this test until the transmitters are replaced. The transmitters will not be onsite until late this week. W 10.2 tests the control functions of the steam generator
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level control system. The safety-related functions are tested during the normal surveillance program, and the current protection setpoints for steam flow and feedwater flow are conservative with respect to the assumptions on the safety analysis.
SU 1.1
" Loss of Offsite Power" is a test of system response to a loss of offsite power. We propose to do this test following the performance of W i
10.2 discussed above. Postponing this trip will allow plant operating data to be obtained at the 50 percent power level before tripping the plant.
This operating time will allow us to take more data to use in optimizing control systems such as steam generator levels and uncever any additional operating problems which can be corrected during such a shutdown. We do not believe it is necessary to provide an additional demonstration of plant capability to cope with loss of offsite power before reaching the 50 percent power level since the plant has demonstrated such capability during the special test program. During that test the 6.9 kV shutdown boards were 4
deenergized from the offsite system, the diesel generators automatically started on the blackout signal,.and all emergency loads sequenced onto the shutdown boards.
SU 1.2
" Shutdown from Lotside the Control Room" consists of two parts:
i
( A) reactor trip and F t shutdown from the backup control room, and I
(B) a cooldown from the backup control room. Part ( A) of the test would be t
performed before reaching 100 percent power. This part would be performed at approximately 30 percent power but at a time more suitable to reactor operating conditions. This position is consistent with the requirements of Regulatory Guide 1.68.2 which requires that the test be done above 10 percent power. Part (B) of this test (the cooldown) would be performed i
following the negative rate trip from 50 percent ower. During the pre-operational test program all components required to safely shutdown the reactor from outside the control room were functionally tested. In addition, a cooldown was performed from outside the control room during the hot functional test program.
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