ML18029A318
| ML18029A318 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 12/21/1984 |
| From: | Domer J TENNESSEE VALLEY AUTHORITY |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8412270375 | |
| Download: ML18029A318 (25) | |
Text
REGULATORY FORMATION DISTRIBUTION SY M.(RIDS)
ACCESSION NBR'8012270375 DOC ~ DATE: 8'/12/21 NOTARIZED: YES DOCKET ¹ FACIL:50 259 Browns Ferry Nuclear Power Station~
Unit 1i Tennessee 05000259
~
AUTHeNAME AUTHOR AFFILIATION DOMERrJ ~ A~
Tennessee Valley Authority RECIP,NAME RECIPIENT AFFILIATION DENTONiH.R ~
Office of Nuclear Reactor Regulationi Director
SUBJECT:
Requests exemption from test interval requirements of 10CFR50gApp J
due to current refueling outage projected to lest until Summer 1985 'ist of applicable components 8
justification encl'ISTRIBUTION CODE; A017D COPIES RECEIVED:LTR
'NCL SIZEe. r3.
TITLE:
OR Submittal:
Append J Containment Leak Rate Testing NOTES:NMSS/FCAF icy'cy NMSS/FCAF/PM.
OL',Ob/26/73 05000259 REC IP IENT ID CODE/NAME NRR ORB2 BC 01 INTERNAL; ACRS 07 ELD/HOSE 08 NRR/DSI/CSB 06 RGN2 COPIES LTTR ENCL 7
7 10 10 1
1 1
1 RECIPIENT ID CODE/NAME ADM/LFMB NR ASB REG ILE.
00 COPIES LTTR ENCL 1
0 1
1 1
1 EXTERNAL; LPDR NSIC NOTES' 1
1 2
2 NRC PDR NTIS 02 TOTAL NUMBER OF COPIES REQUIRED:
LTTR 29 ENCL 28
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TENNESSEE VALLEYAUTHORITY CHATTANOOGA. TENNESSEE 37401 400 Chestnut Street Tower II December 21, 1984 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 No. 50-259 TVA is 10 CFR unit 2 summer 1 in a needed hereby requesting an exemption from the test interval requirements of 50 Appendix J for the Browns Ferry Nuclear Plant unit 1.
Browns Ferry is currently in a refueling outage which is projected to last until 1985.
To avoid or minimize overlap of outages, we-'plan to operate unit lengthy period of coastdown.
Approval of the requested exemption is to support those plans.
The list of components for which the extension is requested is provided in enclosure
-1.
Included are notes explaining why the components cannot be tested or pr oviding additional information; As explained in enclosure 1, we are planning to test those components that can be tested while operating.
During the last outage on Browns Ferry unit 1, inspections of stainless steel piping revealed the presence of intergr anular stress corrosion cracking.
As a'esult TVA applied weld overlays to the cracked welds.
Justification for extended operation with the overlaid welds is pr ovided in enclosure 2.
It is projected that unit 1 will reach depletion of reactivity (start of power coastdown) by mid-February 1985.
There is a degree of inherent protection in power coastdown.
Specifically, operation in power coastdown results in reductions in maximum power capability.
Ensuing margins to safety limits increase dramatically as maximum capability decreases.
Furthermore, coastdown operations at Browns Ferry have demonstrated an exceptionally stable and safe mode of operation.
Scram frequency during coastdown is about half that observed during normal full-power operation.
Additional discussion is provided in enclosure 3.
It is pr ojected that unit 1 will shutdown and start its refueling outage in early June 1985.
However, to allow for schedular flexibilityand uncertainty the exemption is requested to allow operation until October 1,
1985.
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l An Equal Opportunity Employer
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Mr. Harold R. Denton December 21, 1984 Similar requests for exemption from 10 CFR 50 Appendix J requirements for Browns Ferry have been approved in the past.
A pr evious exemption for unit 1
was forwarded by letter from D. B. Vassallo to H. G. Parris dated April 8,
- 1983, and previous exemption for unit 2 was forwarded by letter from D. B. Vassallo to H. G.
Par ris dated August 13, 1984.
As reflected by the dates provided in the enclosure 1 list of components, the initial testing of components comes due about mid-April 1985.
Approval of the enclosed Appendix J exemption is therefore needed by April 3, 1985.
If you have any questions, please get in touch with us through the Browns Ferry Project Manager.
Very truly yours, TENNESSEE VALLEY AUTHORITY 4~.~
ames A. Domer Nuclear Engineer Subscribed apd sworn to efore me this ~~
day of 1984.
Notary Public My Commission Expires Enclosures cc (Enclosures):
U.S. Nuclear Regulatory Commission Region II ATTN:
James P. O'Reilly, 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, Mar yland 20814
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ENCLOSURE 1
10 CFR 50 APPENDIX J EXEMPTION REQUEST BROWNS FERRY NUCLEAR PLANT UNIT 1
Com onents Reauirin Local Leak Rate Testin (LLRT)
Because of anticipated delays in the startup of Browns Ferry unit 2, we are scoping the requirements to operate Br owns Ferry unit 1 beyond the scheduled shutdown (fate presently set for April 1985 to a projected unit 1, cycle 6 outage start date of early June 1985.
This schedule will surpass the test intorval, as stated in Appendix J to 10 CFR 50, oz a'umber of primary containment system components.
Me are therefore requesting an exemption from the test interval requirements of 10 CFR 50, Appendix J for Browns Ferry unit 1.
The request is for exemption to October 1,
1985.
Listed below are the components for which an extension to the test interval will be required.
Included in this attachment is the surveillance interval end date for each component with explanatory notes.
These notes indicate which components were not exposed to temperature,
- pressure, and other conditions which would potentially degrade the leak rate performance of the component, subsequent to testing during the cycle 5 refueling outage.
This outage ended January 2,
1980.
The following list contains components with a note 3.
This note specifies that those components can be tested while at power.
TVA will test those components as required by Appendix J.
No exemption is requested for those components.
1 J
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4
IB (Inboard)
OB (Outboard)
Component Number Descri tion Expiration Date Note(s)
Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Be'ws Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows Bellows X-7A IB X-7A OB X-7B IB X-7B OB X-7C IB X-7C OB X-7D IB X-7D OB X-8 IB X-8 OB X-9A IB X-gA OB X-9B IB X-9B OB X-10 IB X-10 OB X-11 IB X-11 OB X-12 IB X-12 OB X-13A IB X-13A OB X-13B IB X-13B OB X-14 IB X-14 OB X-16A IB X-16A OB X-16B IB X-16B OB X-17 IB X-17 OB Primary Steamline Primary Steamline Primary Steamline Primary Steamline Primary Steamline Primary Steamline Primary Steamline Primary Steamline Primary Steamline Drain Primary Steamline Drain Feedwater Line Feedwa r Line Feedwater Line Feedwater Line Steamline to RCIC Turbine Steamline to RCIC Turbine Steamline to HPCI Turbine Steamline to HPCI Turbine RHR Shutdown Supply Line RHR Shutdown Supply Line RHR Return Line RHR Return Line RHR Return Line RHR Return Line Reactor Water Cleanup Line Reactor Water Cleanup Line Core Spray Line Core Spray Line Core Spray Line Core Spr ay Line RHR Head Spray Line RHR Head Spray Line 7-13-85 7-13-85 7-13-85 7-13-85 6-16-85 6-16-85 6-16-85 6-16-85 7-13-85 7-13-85 A=14-S5
'7-14-85 7-13-85 7-13-85 7-14-85 7-14-85 7-14-85 7-14-85 6-15-85 6-1'5-85 6-16-85 6-16-85 6<<15-85 6-15-85 6-30-85 6-30-85 6-28-85 6-28-85 6-28-85 6-28-85 6-30-85 6-30-85 1,4 1,4 1,4 1,4 1,4 1,4 1,4 l ~w 1,4 1,4 1,4 1,4 1,4 1,4 3
3 3
3 3
3 4,5 1
p 3 1 l3 1
$ 3 1 f3 1,3 3
4J CV
Com onent No.
Descri tion Expiration Date Note(s)
Elec. Penetration Elec Penetration Elec Penetration Elec Penetration Elec Penetration.
Elec Penetration.
Elec Penetration Elec Penetration Elec Penetration-Elec Penetrati'on Elec Penetration Elec Penetration Elec Penetration Elec Penetration Elec Penetration Elec Penetration Elec Penetration Elec Penetration Elec Penetration Elec Penetratibn Elec Penetration Elec Penetration Elec Penetration Elec Penetration Elec Penetration Elec Penetration Elec Penetration Elec Penetration Elec Penetration Elec Penetration Elec Penetration Elec Penetration X-104E X-104F Indication
& Control Indication
& Control X-105B Recir Pump Power X-105C Recir Pump Power X-105D X-106A X-106B X-107A X-107B X-108A X-108B X-109 X-110A X-110B X>>219 Spare CRD Rod Position Indic Neutron Monitoring Neutron-Monitoring Spare Power CRD Rod Position Indic CRD Rod Position Indic Power CRD Rod Position Indic Vacuum Breaker Inst X-100A--Indication- & Control X-100B Neutron Monitoring X-100C Neutron Monitoring X-100D Neutron Monitoring
-X-100E
- Neutron-Monitoring X-100F Neutro4 n-'Monitoring
.X-100G
-'CRD Rod Position Indic
- X-101A Recir Pump-Power
-X-101B
'Recir Pump Pojwer
= X-101C
-"Recir Pump Power X-101D Recir Pump Power
, X-102 Thermocouples
-X-103 CRD Rod-Position Inc'~.
. X-104A Indication
& Control
-X-104B CRD Rod Position Indic X-104C Neutron Monitoring X-104D
'Thermocouples 4-24-85=
4-24-85 4-27-85 4-26-85 4-'6-85 4-28-85 4-25-85 8-'5-85 8-5-85 4-28-85 4=28-85 4 g5-86..
.4-26 "~
4-24-85 4-24-85 4-24-85 4-27-85 4-a7-85 4-27-85 8-5-85 4-28-85 4-27-85 4-24-85 4-25-85 4-'24-85 4-24-85 8-5-85 4-2S-8S 4-25-85 8-5-8S 4-25-85 4-27-85 1 1 3 1 1 3 1
1 3 113 1
1 3 1 1 3 1 1 3 1.6 1,6 1.6 1,6 1
1 3 1 1 3 113 1
1 3 113 1,3 1 1 3 113 1,6 1,6 113 1 1 3 1 1 3 1 1 3 1)3 1 1 3 1 1 3 1
1 3 1
1 3 1 1 3 1 1 3 Double 0-Ring Seal Double 0-Ring Seal Double 0-Ring Seal Double 0-Ring Seal Double 0-Ring Seal Double 0-Ring Seal Double 0-Ring Seal Double 0-Ring Seal X-4 X-35B X-35C X-35D X-35E X-35F X-35E X-47 DW Head Access Hatch T.I.P.
Dr ive T.I.P. Drive T.I.P. Drive T.I.P. Drive T.I.P. Drive T.I.P. Drive Power Operation Test 8-31-85 8-3-85 8-3-85 8-3-85 8-3-85 8-3-85 8-3-85 8-5-85 1 )7 1 1 3 1 1 3 1 1 3 1 1 3 1 1 3 1 1 3 1,5 r
~Com anent Valve Valve Valve Valve Valve Valve Valve Valve Ualve Valve Valve Valve Valve Valve Val ~'e Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Ualve Valve Ualve No.
1-14 1-15 1-26 1-27 1-37 1-38 1-51 1-52 1-55 1-56 2-1192 2-1383 3-554
~-558 3-568 3-572 12-738 12-741 32-62 32-63 32-336 32-.2163 33-785 33-1070 43-28A 43-28B 43-29A 43-29B Descri tion Main Stream Main Steam Main Steam Main Steam Main Steam Main Steam Main Steam Main Steam Main Steam Drain Main Steam Drain Service Mater Service Mater Feedwater Feedwater Feedwater Feedwater Aux Boiler to RCIC Aux Boiler to RCIC Drywell Comp Section Drywell Comp Section Drywell Comp Return Drywell Comp Return Service Air Service Air Rx Water Sample Line Rx Water Sample Line RHR Supp Chamber Sample RHR Supp Chamber Sample RHR Supp Chamber Sample RHR Supp Chamber Sample Line Line Line Line xpiration Date 8-8-85 8-27-85 8-16-85 6-1-85 8-10-85 9-27-85 8 16-85 8-27-85 4>>19-85 4-19-85 4-21-85 4-21-85 5-7-8S "7-85, 7-22-85 7-21-85 4-20-85 4-20-85 4-21-85 4-21-85 4-22-85 4-22-85 4-22-85 4-22-85 5-5-85 5-5-85 9-11-85 9->>-85 9-12-85 9>>12-85 Note(s) 1 $ 7 1 $ 7 1
$ 7 1.7 1$ 7 1$ 7 1.7 1.7 1
$ 7 1.7 7
7 1
1
$ 7 1 $ 7 117 1$ 3 1$ 3 1
1 1$ 7 1
$ 7 7
7 1$ 7 1
$ 7
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3 3
Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Ualve Valve 63-525 63-526 68-508 68-555 69-.1 69-2 69-579 71-2 71~3 71-14 71-32 71-580 71-592 73-2 73-3 73-23 73-24 73-44 73-45 73-81 73-603 SLC Discharge SLC Discharge CRD to RC Pump Seals CRD to RC Pump Seals RWCU SupPly RWCU SuPply RWCU Return RCIC Steam SuPPly RClC Steam SuPP1Y RCIC Turbine Exhaust RCIC Vacuum Pump Discharge RCIC Turbine Exhaust RCIC Vacuum Pump Discharge HPCI Steam Supply HPCI Steam Supply HPCI Turbine Exhaust HPCI Turbine Exhaust Drain HPCI Pump Discharge HPCI Pump Discharge HPCI Steam Supply Bypass HPCI Turbine Exhaust 5-5-85 5-5-85 9-25-85 9-25-85 9-10-85 9-10-85 7-23-85 4-19-85 4-19-85 4-19-85 4-19-85 4-19-85 4-19-85 4-22-85 4-22-85 4-24-85 4-21-85 5-7-85 5-7-85 4-22-85 4-24-85 1 $ 7 1$ 7 7
7 7
7 7
1 $ 7 1 $ 7 1,8 1,8
~ 1,8 1,8 1 $ 7 1
$ 7 1,8 1,8 1 $ 7 1,7 1.,7 1,8
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~Com onent Valve Ualve Valve Valve Valve Valve Valve Valve Ualve Valve Valve Ualve Valve Valve Valve Valve Valve Valve Ualve Valve Valve Valve Ualve Valve Valve Ualve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Valve Ualve Valve Valve Valve No.73-609 74-53 74 54 74-57 74-58 74-60 74-61 74-67 74-68 74-71 74-72 74-74 74-75
'4-77 74-78 74-661 74-662 74-722 75-57 75-58 76-49 76-50 76-51 76-52 76-53 76=-54 76-55 76-56 76-59 76-60 76-61 76-62 76-63 76-64 76-65 76-66 77>>2A 77-2B 77-15A 77-15B 85-576 90-254A 90-254B 90-255 90-257A 90-257B Descri tion HPCI Turbine Fxhaust Drain RHR Shutdown Suction RHR LPCI Discharge RHR LPCI Discharge RHR SC Spray RHR SC Spray RHR DW Spray RHR DW Spray RHR LPCI Discharge RHR LPCI Discharge RHR SC Spray'HR SC Spray RHR DW Spray RHR DW Spray RHR'Head Spray RHR Head Spray RHR Shutdown Suction RHR Shutdown Suction RHR SC Dr'ain CS to Aux Boiler CS to Aux Boiler Containment Atmospheric Mon Containment Atmospheric Mon Containment Atmospheric Mon Containment Atmospheric Mon Containment Atmospheric Mon Containment Atmospheric Mon Containment Atmospheric Mon Containment Atmospheric Mon Containment Atmospheric Mon Containment Atmospheric Mon Containment Atmospheric Mon containment Atmospheric Mon Containment Atmospheric Mon Containment Atmospheric Mon Containment Atmospheric Mon Containment Atmospheric Mon DW Floor Drain Sump DW Floor Drain Sump DW Equipment Drain Sump DW Equipment Drain Sump CRD Hydraulic Return Radiation Monitor Suction Radiation Monitor Suction Radiation Monitor Suction Radiation Monitor Discharge Radiation Monitor Discharge Date 4-21-85 5-8-85 5-6-85 5-6-85 8-16-85 8-16-85 5-'5-85 5-5-.85 5-7-85 5-7-85 5-7-85 5-7-85 5-8-85 5-.8. 5-'8-".5 5-'8-85.
5-8-85 5-8-85 9-14-85 5-3-85 5-3-85 4-23-85 4-23-85 4-23-85 4-23-85 9-29-85 9-29-85 9-29-85 9-29-85 4-23-65 4-23-85 4-23-85 4-23-85 9-29-85 9-29-85 9-29-85 9-29-85 4-24-85 4-24-85 4-24-85 4-24-85 7-23-85 4-17-85 4-17-85 4-17>>85 4-17-85 4-17-85 Note(s) 1,8 772 7/2 1,8 1,8 1,8 1,8 7)2 7 f2 1,8 1,8 1,8 1,8 1~7~-
11712 7
7 1,8 1s8 1
$ 7 1
p 7 1
p 7 117 1 g 7 1
1 )7 117 1 p 7 1
117 177 1
1>7 1 g 7 1 f7 7
7 7
7 7
1,3 1
g 3 1 f3 1,3 1 f 3 kP
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Note 1:
Component w
not exposed to normal operatin conditions of temperature,
- pressure, or other operating conditions subsequent to testing during the cycle 5 outage which would tend to degrade leak rate performance.
Note 2:
Note 3:
Valve was used to support shutdown operations and
<<s normally open in a post LOCA condition.
Component is located in relatively moderate temperature and radiation area.
Can be tested at power.
Note 0:
Component cannot be tested during power operations due to heat stress.
Ambient temperature is 100-160oF.
Note 5:
Component cannot be tested during operation due to high radiation levels that exist during power operation.
General area is greater than 200 mr/hr.
Note 6:
Electrical penetration is on the supply to a recirculation pump.
Power must be removed by opening the associated MG breaker.
The unit should not be operated with only one recirculation loop, therefore the penetration cannot be tested at power.
Note 7:
Component cannot be tested because:
(1)
The unit must be shut down and the containment deinerted to facilitate access to the component, or (2)
The unit must be shut down so that affected systems can be properly vented for testing.
Note 8:
Valve cannot be tested at power because it would require entering an LCO condition of technical specifictions in order to perform the LLRT.
In addition, SIs must be performed on related safety systems in order to prove their operability.
Performance of these SIs to accommodate LLBT represents an unnecessary challenge to plant safety systems.
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ENCLOSURE 2 Extension of, AnorovaMfor 0 eration with Weld Overla to October 1
1985 The SER as related to intergranular stress corrosion cracking (IGSCC) in Browns Ferry unit 1 documented NRC concurrence that unit 1 could be safely returned to power at the beginning of fuel cycle 6 and could be safely operated in its present configuration for at least one fuel cycle.
Since TVA's plans at that time were for an 18-month fuel cycle, the SER was prepared using 18 months as a reference interval. It is advantageous to TVA to extend the specified 18-month fuel cycle to 21 months.
As such we 7
'~ e providing our evaluati<<;s for a a1-month fuel cycle.
Our evaluation considers the 9 unrepaired cracked welds, the 3 replaced defective welds, the 42 overlaid welds, and the 25 uninspectable welds.
Based on our evaluations, our conclusion is that unit 1 can be operated safely in its present configuration for at least one 21-month fuel cycle.
Our evaluations of the 9 unrepaired cracked welds show that final crack sizes at the end of a 21-month fuel cycle are well within the limits of IWB-3640 even if the initial crack sizes are doubled.
Therefore, we conclude that the Code design safety margins will be maintained for each of these welds for at least a 21-month fuel cycle.
Defective welds (1 core sPray, weld DCS-1>>2; and 2
RWCU welds, DSRWC-1-2 and DSRWC-1-3) were replaced with 304 NG stainless steel using heat-sink welding.
Stainless steel material (304 NG) is considered resistant,to IGSCC.
Heat-sink welding produces favorable compressive residual stresses at the inner surface further inhibiting IGSCC initiation and growth; therefore, we conclude that the 3 replaced defective welds are acceptable for at least a 21-month fuel cycle.
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The analyses provided by NUTECH Engineers and Structural Integrity Associates (SIA) demonstrate that each of the overlays will inhibit further crack growth even if the crack sizes are doubled with the exception of overlaid weld GR-1-41.
These postulated initial crack sizes (twice the initial sizes) are within the limits of I>TB-3640.
The NUTECH analyses demonstrate that the crack growth in weld GR-1-41 will be arrested after 60 months of operation, even if the initial crack size is doubled.
This arrested crack depth is within the limits of INB-3640; therefore, we conclude that these engineered overlays wi" provide adeqv."" e assurance of safe operation for at least a 21-month fuel cycle.
Also, we conclude that 0he full structural overlay on weld DRMC-1-1A will provide assurance of safe operation for at least a 21-month fuel cycle because the overlay weld material inhibits IGSCC.
Based on the same reasoning in the safety evaluation report, we conclude that the 25 welds not examinable by ultrasonic testing will not create any major safety problem during continuous operation of the plant for a 21-month fuel cycle.
In summary, we conclude that, Browns Ferry unit 1 can be safely operated, with respect to piping integrity, in its present configuration for at least a 21-month fuel cycle.
ENCLOSURE 3
Performance of Browns Ferry Reactors During Coastdown The frequency of reactor scrams during long coastdowns
( >1500 MHd/STU) at Browns Ferry has been significantly lower than the frequency observed during the full-power operational portion of the cycles.
Based on the Browns Ferry monthly operating reports for U2CO, U2C5,wand U1C5 (with "l coastdowns valying from approximately 1550 to 2800
.""rid/STU), the scram frequency during coastdowns was less than half the frequency during full<<power operation.
During coastdown, ther e are no requirements for power changes for control rod movements since all rods are normally withdrawn and ther e are no sequence exchanges or rod adjustments.
Also, surveillance tests and some maintenance that must be done at less than full power can be performed without changing power or with a smaller power reduction.
Mar gin to scram setpoints on power level and margin to thermal limits increase with coastdown (see figures 1
and 2 for examples).
The reduction in required power maneuvers and increase in the margin to scram setpoints result in improved operating flexibilityand are at least par t of the reason for reduced scr ams during coastdown.
The characteristics of a coastdown necessary to extend cycle 6 of BFN unit 1 are shown in figure 3.
Depletion of full-power reactivity is expected to occur in February 1985.
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1.6 Figure 1: Ratio of MAPLHGR and LHGR fo Limiting Values, BF1 CY5 1.4 1.2 OI-10 0.8 0
., UR,:, pPQ 0
START OF COASTDOWN LlMIT 0.6 4
6 8
10 C'ycle Exposure (GWD/MT) 12 14
~ 2.0 Figure 2: MCPR vs Cycle Exposure BF1 CYG 1.8 START OF 0 COASTDOW 1.6 C3 1.4 oo o 0 CD oo 0
LIMIT 1.2 1.0 4
6 8
10 Cycle Exposure (GWD/MT)
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FlgUI'8 3: COBstdQwn Powel'evel JBF:l. CYG 100 80 70 60 0
E 60 I-
~o 40 20 10 0-~
.6 8,0 8.6 9.0 9.6 10 0 10.6 11.0 Cycle Exposure (GN/D/ST) 70 7
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