ML18029A910
| ML18029A910 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 10/11/1985 |
| From: | Shell R TENNESSEE VALLEY AUTHORITY |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8510160153 | |
| Download: ML18029A910 (8) | |
Text
ACCESSION NBR F ACIL:50-259 50-260
- 50. 296 AUTHiNAME SHELL'gR AH, REC IP ~ NAME>>
DENTONiH ~
RE
REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
- 8510160153 DOC ~ DATE
- 85/10/11 NOTARIZED:
YES DOCKET Browns Ferry Nuclear>> Power.- Stationi Unit 1<., T'ennessee>>
05000259 Br owns Ferry Nuclear~ Power. Station~
Unit>> 2< Tennessee.'5000260 Browns Ferry Nuclear Power. Stationi Unit'~ Tennessee 05000296 AUTHOR Af FILIATION Tennessee Val 1 ey Author i ty RECIPIENT AFF IL>>IATION Office of Nuclear Reactor>> Regulationi Director SUBJECT;= Submits schedu.le. to meet requirements of,10CFR50
~ 62(c)(1)<<
(c)(5) re reduction of risk from ATWS,Final implementation of mods to meet Paragraphs (c)(3),8 (c)(0) scheduled for>>
Unit 1 Cycle 7~Unit 2 Cycle 6
8 Uni,t 3 Cycle 7 outages;
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DISTRIBUTION CODE:
A055D COPIES RECEIVED:LTR-
"ENCl>>
SIZE; TITLE; OR/Licensing Submittal; Salem ATWS'vents GL 83 28 NOTES:NMSS/FCAF 1cy ~
1cy NMSS/FCAF/PM'L!06/26/73 NMSS/FCAF 1cye 1cy NMSS/FCAF/PM'L:06/28/7Q NMSS/FCAF 1cy ~
1cy NMSS/FCAF/PM'Lo07/02/76 05000259 05000260 05000296 RECIPIENT ID CODE/NAME, NRR ORB2 BC 01 INTERNAL; ACRS ELD/HOSE IE/DQAVT NRR/DE/MEB NRR/DHFS/LQB NRR/DL/DRAB, NRR/DL/TAPMG NRR/DSI/ICSB NRR/DSI/RSB RGA2 COPIES LTTR ENCL 6
1 1
1i 2
1i RECIPIENT ID CODE/NAME; ADM/LFMB IE/DI>>
NRR/DE/EQB NRR/DHFS/HFEB NRR/DL D IR NRR/DL/SSPB NRR/DS I/AS8 NRR/DSI/PSB 0'OPIES LiTTR ENCL 1
1 1
1 1
1 1
1 1
EXTERNAL'4X NRC PDR NOTES'2:
LPDR NSIC 03 05 1
1 1
1
-TOTAL NUMBER'F COPIES REQUIRED:. LTTR 30 ENCL
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TENNESSEE VALLEYAUTHORITY CHATTANOOGA, TENNESSEE 37401 400 Chestnut Street Tower II October 11, 1985 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Mr. Denton:
In the Matter of,-the, Tennessee Valley Authority Docket Nos.
50-259 50-260 50-296 As you are aware, each licensee is required to propose a schedule for meeting the requirements of paragraphs (C)(1) through (C)(5) of 10 CFR 50.62, reduction of risk from Anticipated Transients Without Scram (ATWS). Paragraphs (C)(1) and (C)(2) of 10 CFR 50.62 apply only to pressurized water reactors and are not applicable to Browns Ferry Nuclear Plant (BFN).
Alternate Rod In ection ARI Paragraph (C)(3) requires each boiling water reactor to implement an ARI system.
The BFN conceptual ARI design provides an energize-to.-trip signal opening the existing backup scram valves upon low reactor water level or high reactor pressure with 2 out of 2 logic.
By opening the backup scram
- valves, the scram air header will be quickly depressurized resulting in insertion of the control rods independent of the reactor trip system.
The ARI system will be powered independently of the reactor trip system by a reliable DC power supply which will be capable of performing the safety function with a loss of offsite power. It will share common logic and sensors with the Recirculation Pump Trip (RPT) system.
Standb Li uid Control SLC)
Paragraph (C)(4) requires each boiling water reactor to maintain an SLC system with a minimum flow capacity and boron content equivalent in control capacity to 86 gallons per minute (gpm) of 13-weight percent sodium pentaborate solution.
At BFN two design concepts are currently being evaluated.
The first SLC system design consideration includes modifying the system such that both pumps are activated, after system initiation, injecting 86 gpm of the present sodium pentaborate solution.
The second SLC system design under consideration incorporates the use of Boron-10 enriched sodium pentaborate solution in the SLC system.
By using Boron-10 enriched sodium pentaborate solution, the 86 gpm, 13-weight percent equivalent control capacity can be obtained with the current single SLC 8510160153 851011 PDR ADDCK,'05000259 P,
PDR An Equal Opportunity Employer
C ll
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Mr. Harold R. Denton, Director October ll, 1985 system pump design.
A decision on which SLC system approach is implemented is pending an economic evaluation of the two options.
Our implementation schedule is based on the two-pump option, which has the longest lead time.
Recirculation Pum Tri RPT Paragraph (C)(5) requires each boiling water reactor to have an automatic RPT under conditions indicative of an ATWS.
At BFN an RPT system which meets the 10 CFR 50.62 rule has already been installed.
Modifications will initiate the reactor RPT from the same logic network as the ARI system.
A trip of two independent channels (2 out of 2 logic) will be required to initiate the RPT.
The RPT will be an energized-to-trip system.
Once the RPT relays have tripped, both reactor recirculation pump normal and emergency motor generator feeder breakers will open, allowing the reactor recirculation pumps to coast down.
Final implementation of the modifications to meet paragraphs (C)(3) and (C)(4) of 10 CFR 50.62 is scheduled for the unit 1 cycle 7 outage, unit 2 cycle 6 outage, and unit 3 cycle 7 outage.
The modifications to the existing RPT systems outlined in the previous paragraph will be done concurrently with installation of the ARI systems.
Specific dates for these refueling outages are contained in the Browns Ferry integrated schedule.
This schedule complies with the 10 CFR 50.62(d) requirement of final implementation no later than the second refueling outage after July 26, 1984 for all BFN units, Very truly yours, TENNESSEE VALLEY AUTHORITY R. H. Shell Nuclear Engineer Sworn t ~nd subscr' b fore me this
~ day of 1985 Notary Public My Commission Expires cc:
(See Page 3)
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Director of Nuclear Reactor Regulation October ll, 1985 cc:
U.S. Nuclear Regulatory Commission Region II Attn:
Dr. J. Nelson Grace, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. R. J. Clark Browns Ferry Project Manager U.S. Nuclear Regulatory Commission 7920 Norfolk Avenue
- Bethesda, Maryland 20014
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