ML18031B241
| ML18031B241 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 03/05/1987 |
| From: | Domer J TENNESSEE VALLEY AUTHORITY |
| To: | Muller D NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.K.3.18, TASK-TM NUDOCS 8703160317 | |
| Download: ML18031B241 (8) | |
Text
ACCESSION NBR FAC IL: 50-259 50-260 50-296 AUTH. NANE DONERi J. A.
NILLER> D. R.
REGULATORY
'ORI'IATION DISTRIBUTION.BY N (R IDS) 8703160317 DQC. DATE: 87/03/05 NOTARIZED:
NQ DOCH.ET Brogans Ferry Nuclear Pouer Station>
Unit ii Tennessee 05000259 Brogans Ferry Nuclear Paver Stationi Unit 2 Tennessee 05000260 Brogans Ferry Nuclear Pouer Stations Unit 3i Tennessee 05000296 AUTHOR AFFILIATION Tennessee Valieg Authority RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
OFfice oF Nuclear Reactor Regulationi Director (post 851125
SUBJECT:
InForms that automatic depressurization sos (ADB) logic vill be modified to allo+ ADS to initiate vessel depressuri zationi per 860724 meeting m/NRC re closing NUREQ-0737> Item II. K. 3. 18 issues.
DISTRIBUTION CODE:
A003D COPIES RECEIVED: LTR ENCL SI ZE:
TITLE: OR/Licensing Submittal:
Supp l 2 to NUREQ-0737(QeneT ic Ltr 82-33)
NOTES: NNSB/FCAF 2cg.
NNSB/FCAF/PN icy. OI* 2cg.
NNBB/FCAF 2cg.
NNBS/FCAF/PN icy.
OIA 2cg.
NlIBB/FCAF 2 c g.
NNSB/FCAF/PN 1 c g.
QIA 1 c g.
05000259 05000260 05000296 RECIPIENT ID CODE/NANE BMR ADTS BMR EICBB BMR PD2 LA QROTENHUIS, I f BMR RBB INTERNAL: ADN/LFNB NRR BMR ADTB NRR/DSRO El'fR IT NRR/DSRQ/RBIB EXTERNAL LPDR NBIC NOTES:
COPIES LTTR ENCL 1
1 2
2 1
1 1
1 1
0 1
1 1
IE/DEPER/EPB NRR PMR-B ADTS RO/EIB REQ FI 01 NRC PDR RECIPIENT ID CODE/NANE BMR EB BWR FOB BMR PD2 PD BMR PSB COPIEB LTTR ENCL 1
7 7
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1 1
1 1
TOTAL NUNBER OF COPIES REQUIRED:
LT1 R 33 ENCL 32
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TENNESSEE VALLEYAUTHORITY CHATTANOOGA. TENNESSEE 37401 5N 1578 Lookout Place MAR 05 1II7 U.S. Nuclear Regulatory Commission Attn:
Document Control Desk Office of Nuclear Reactor Regulation Hashington, D.C.
20555 Attention:
Mr. D.
R. Muller In the Hatter of the Application of
)
Tennessee Valley Authority
)
Docket Nos.
50-259 50-260 50-296 BROHNS FERRY NUCLEAR PLANT (BFN) MODIFICATIONS TO AUTOMATIC DEPRESSURIZATION SYSTEM (ADS) LOGIC NUREG-0737, I'TEM II.K. 3. 18 The subject NUREG-0737 item calls for modification of the ADS logic in order to eliminate the need for manual action to depressurize the reactor during certain accidents and transients.
The current ADS logic requires, in part, a
lo-lo-lo reactor water level signal in conjunction with a high drywell pressure signal in order to actuate.
Certain non-LOCA scenarios accompanied by failure of all high pressure makeup require manual action to depressurize the reactor and permit makeup from low pressure systems.
In response to the NUREG, the Boiling Hater Reactor Owners Group (BHROG) performed a study and identified modifications that would satisfy the. basic concerns.
NRC reviewed the'HROG study and by letter to H.
G. Parris from D.
B. Vassallo dated June 3,
- 1983, requested that TVA choose one of two options.
The options acceptable to NRC were (1) elimination of the high drywell pressure permissive and addition of a manual inhibit switch or (2) bypass of the high drywell pressure permissive after a sustained low water level and addition of a manual inhibit switch.
In past correspondence with NRC, TVA agreed that the proposed options could be implemented without reducing plant safety, although our basic position was that the existing BFN ADS logic was adequate.
The most recent correspondence is a letter from R. L. Gridley to you dated March 26,
- 1986, in which the TVA position is summarized.
To close the issue, a meeting was held with, the'NRC staff on July 14, 1986.
Subsequently, we elected to implement a modification similar to option two described above.
The ADS logic wi 1 1 be modified to allow the ADS to initiate vessel depressurization, automatically bypassing the high drywell pressure signal 10 minutes after a s'ustained lo-lo-lo reactor vessel water level signal.
This 10-minute delay will consist of a new eight-minute bypass timer in conjunction with the existing ADS two-minute timer.
A manual switch will also be installed to allow the operator to inhibit the ADS as recommended by the BHROG Emergency Procedure Guidelines.
,8703160317 870305
'PDR ADOCK 05000259 P
PDR An Equai Opportunity Employer
U.S.
Nuclear Regulatory Commission MAR 06 1987 General Electric Company previously performed an analysis (NEDO 24266, "DC Power Source Failure for Browns Ferry Nuclear Power Station Units 1, 2, and 3"), which was provided to NRC in our letter dated March 26, 1986.
The analysis shows that for a worst-case primary system break in combination with a loss of high pressure
- makeup, depressurization of the reactor within 10 minutes will maintain peak cladding temperature well below 2,200'F.. Ten minutes is also sufficient time for the operator to take manual action in accordance with operating instructions and depressurize the reactor in a controlled manner.
This ADS logic modification and submittal of appropriate technical specifications is scheduled for completion during the cycle 7 refueling outage for BFN unit 1
and cycle 6 refueling outage for BFN units 2 and 3
~
If you have any questions or need further information, please get in touch with J.
L. Turner at (205) 729-2853.
Very truly yours, TENNESSEE VALLEY AUTHORITY u~
J.
A. Domer, Assistant Director Nuclear Safety and Licensing cc:
See page 3
4 I
l I y'
0 U.S. Nuclear Regulatory Commission MAR 06 1887 cc:
U.S. Nuclear Regulatory Commission Region II Attn:
Dr. J.
Nelson Grace, Regional administrator 101 Marietta Street, NN, Suite 2900 Atlanta, Georgia 30323 Mr. G.
E. Gears Browns Ferry Project Manager U.S. Nuclear Regulatory Commission 7920 Norfolk Avenue
- Bethesda, Maryland 20814 Mr. G.
G.
2ech, Director TVA Projects U.S. Nuclear Regulatory Commission 101 Marietta St.,
NH, Suite 2900 Atlanta, Georgia 30323 Browns Ferry Resident Inspector Browns Ferry Nuclear Plant Route 2, P.O.
Box 311
- Athens, Alabama 35611