ML20064K387
| ML20064K387 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 01/12/1983 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | Adensam E Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.E.3.1, TASK-TM NUDOCS 8301180381 | |
| Download: ML20064K387 (2) | |
Text
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N TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 374ol 400 Chestnut Street Tower II January 12, 1983 Director of Nuclear Reactor Regulation Attention:
Ms. E. Adensam, Chief Licensing Branch No. 4 Division cf Licensing U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Ms. Adensam:
In the Matter of
)
Docket Nos. 50-327 Tennessee Valley Authority
)
50-328 A responae to item 2.1.1 of NUREG-0578 was submitted to NRC by my December 10, 1980 letter to A. Schwencer. This item was subsequently incorporated into NUREG-0737 as item II.E.3.1, Emergency Power Supply for-Pressurizer Heaters. Enclosed is our revical response to item II.E.3.1 to clarify the emergency power supply for pressurizer heaters.
If you have any questions concerning this matter, please get in touch with J. E. Wills at FTS 858-2683 Very truly yours, TENNESSEE VALLEY f.UTHORITY L. M. Mills, Kanager Nuclear Licensing Sworn
.dsubsegbedbeforeme this day of Vast #4W 1983 dontdt W. %22_
Notary Public My Commission Expires Enclosure cc:
U.S. Nuclear Regulatory Commission (Enclosure)
Region II Attn:
Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 G301100381 830112 PDR ADOCK 050G0327 P
PDR j
An Equal Opportunity Employer
. y ENCLOSURE:,
Sequoyah Nuclear Plant Revisc.d Response to NUREG 0737, II.E.3.1 7, -
e The following design and administrative control features have been imple=ented to satisfy the staff position:
1.
The pressurizer heaters are powered and contr'olled from Class 1E power sources (see FSAR Figures 8.3-10, 8.3-11, 8.3-12, and 8.3-13).
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The motive and contEol power interfaces ~with the emergency buses are qualified in accordance with safety'l grade requirements. (i.e., each of these interfaces is protected by safety. grade circuit breakers or fuses.)
3 All presst$rizer beater banks are automatically shed from the offsite
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and onsite power ' sources upon the occurrence of a safety injection actuation signal (SIS).
4.
The redun' dant capability for providing power to each bank of heaters is -
shown below.
Power Train Heater Banks 1A d
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1A-A, 1D
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.;~ 1B-B 1B-B, 1C 2A-A, 2D 2A-A
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2B-B 2B-B, 2C The offsite and onsite power sources have sufficient capacity to supply
. the pressurizer beaters.
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5.
If offsite power is available, the SIS is reset, and the water-level'id, -
the pressurizer has recovered backup heater bank 1C is given a Permissive to operate. Under this scenario, if the process auto =atic 6'
control switch is reset, backup heater banks 1 A-A, 1B-B ar,e given a permissive td operate.
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6.
In the event of a loss or offsite power with the SIS reset and the process automatic control switch reset two backup heater banks (1A-A, 1B-B) are given a permissive to operate 90 seconds after emergency Power becomes available. The other backup heater bank (1C) and the
, control bank (1D) would not come en automatically but may be manually
~ ~
. activated if the blackout relays are reset.
7.
The required operator actions are specified in the Sequoyah Emergency operating instructions. If there is a loss of offsite power' the operator has ansneters and voltmeters available to monitor the diesel generator's loading.
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