ML18283B372
| ML18283B372 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 12/01/1977 |
| From: | Gilleland J Tennessee Valley Authority |
| To: | Case E Office of Nuclear Reactor Regulation |
| References | |
| Download: ML18283B372 (9) | |
Text
31STREBUTEQN A ZW ESSUAiXCE OF OPI'ATENG LECZ;tSE VRCFqRM
$ 98 U.S. NUCI.EAR REGULATORY MISSION 2.76)
PlRC DISTRIBUTION PGR PART 50 DOCKET MkTERIAL DOCKET NUMBER Fll F NUMBER
'r. Edson Gi Case.
FROM:
Tennessee Valley Authority Chattanooga, Tennessee.
J~ Ei Gillelard DATE OF DOCUMENT 12/1/77 DATE RECEIVED 12/5/'77
~eTTKR
~OR IGINAI I+COP Y ESCRIPTION ClNOTORI2ED
~NCLASSIFIED PROP INPUT FORM KNCI OSURE NUMSER OF COPIES RECEIVED
/i'tEAdW
,Consists-of corrections to initial report concerning "Electrical Connector Assemblies" submitted on 11/28/77 ~ ~ ~ ~ ~ ~
(1-P)
(6-P)
T)T 4~~+ ~q4fV ~
SAP ~i Browns Ferry Units I.-2-3 RJL 12/5/77 FOR ACTIONitNFORMATION a~~+ K'Ran ail~~
33wXCH CHE "F: (7
'KEG FT INTERNAI 0 ISTRI8UTION
=:(.:-RNAt DISi."ISUTICN i i q<-c-
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I 77339006i
830 Power Building t
December 1,
,r t~t 1977 c
s (1t<',
~~g e
Mr. Edson G. Case, Acting Director Office of. Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
Dear Mr. Case:
In the Matter of
)
Docket Nos, 50-259 Tennessee Valley Authority
)
50-260 50-296 On November 28, 1977, TVA submitted a response to your November 18, 1977, letter to Godwin Williams, Jr., concerning "Electrical Connector Assemblies."
As a result of the continuing review of the above report, we have noted. several corrections which should. be made to the initial report.
These changes are enclosed as Revision 1 to the response.
A listing of the changes is as follows:
l.
2.
3\\
5 ~
6.
Part I, Table 1, page 1 of 3 Part I, Table 1, page 2 of 3 Part I, Table 3, page 1 of 1 Part II, Section B, page 1 Part II,, Section D, page 2
Part II, Section E, page 3
Please get in touch with me if you have any questions regarding this subJect.
Very truly yours, i
I J,
E. Gilleland Assistant Manager of Power Enclosure 7y339006i
t 7.i'uLE t
SYSTEHS MD CQi~IPOilEKTS REQUIB=D TO FUNCTION TO YiITIGATE DESIGN BASIS EVENTS X.'NSIDE PiRXYARY C05T~iH~IT (+'enotes Systems with Connectors) inboard Main Steam Isolation VaIve Circuit s
~Automatic Depressurization Belief'alve Circuits
<nboard Containment Isolation Valve Circuits (See note 1)
= "(hymen,and Hydrogen Monitori:ng Sys ems.
"'Suppre sion Pool to D~rell Vacuum Breakers Recirculation System Suction and. Discharge Valves (See Note 1)
"'Residual Heat Removal System Head. Spray Plow Contzol, Valves (See Note 1)
~Hijh Pr'essure 'Coolant'Inject ion System. Steam 'Supply Valve (See Note 1)
- reactor Coxe Isolation Cooling System Steam Supp~ Valve (See Note 1)
II.
OU~.SIDE PBIMAHv COiNTAii~~"i&ilT A.
Inside Secondary Containment
(* Denotes Systems with Connectors)
""Main Steam Isolation Valve Circuits (See Note 2)
"Automatic.Depressurization Relief Va1ve.Circuits, (See Note 2)
Ll
- Containment Zsolati.on Va1ve Cixcuits (See Note 2)
- (hymen and. ~~drogen Yonitoring Systems (See Note 2)
- 4 KV and 480 V Boards (See Mote 3)
, "Diesel, Generations and. Process Auxiliaxies (See Note 3)
- 4 P/'nd. 400 V System Cixcuits 250 VDC System Circuits Control Bay Ventilation System Circuits (See Note 4)
. Cornex Room (Eley 519}'evel Svitch Cizcuits. (See-Note 5)
Radiation Yionitoring Systems
"- Main Steam Vault
~- PJE Bf Effluent
+- RHCQl
~- BBf Effluent
TABLE 1
(CONT.)
iage l os Diesel:-'Generator-Shuudowri.3oard Room Venti3.ation System Circuits (See Note 4)'Suppression Pool to Drywell Vacuum Breakers
- RCIC Circuits (See Note 6)
- Recirculation System Circuits foz Other Essentia1. Systems (See Note 7)
~'~<<Automatic. Depressurization System
~- Primary Containment Isolation
- Containment Inexting
- Reactor 3uilding Isolation
>>.Reactor Building Vacuum Belief
- Standby Gas Treatment
~ ~
- KiR Room Coolexs
- @~CD CS
- CS Room Coolers
> - HPCX
- << Reactor Protection System (Excluding Neutron Monitoring System, Control Rod Drive and Position Indicating Systems)
- Reactor Building Closed CooJ.in l/Gter
- - Fuel Pool Cooling
- - Reactor Mater Cleanup (Isolati'on Function Oner)
- Torus Uater Level and. Temperature 3.
Control 3~
The control bay environment is controlled by the control bay ventilation
"~
system.
The, environment for equipment within the contzol bay is no more severe during desi~ ba is events than that to which it is exposed during noncal unit operations.
C.
Unit 3, 2~ and p Diesel-Generator Shutdown 3oard Rooms The diesel-penexator shutdown boa'"
"om environments are control3.cd.
by the board. zoom ventilation systems.
The environment for ecpipment within these board. rooms is no more severe during desi~ basis events than that to which they are exposed. during norma1 unit operation.
~Ss tern Function t
TABLE I
CONNECTORS OUTSIDE OF CONTAXNiKNT No. of Devices/
Unit Unit Manufacturer Temperature Envir1
~Desi n men
.'fain S team- '
Line Rad Mon Xnstrumentation.
1',2;3 4
. Ampheno1.
B2-816 350 300
.". actor LJater Cleanup and P imary Con tainment Isolation, 1,2,3 Amphenol MS3106-A-20-4P MS3102-A-20-4S 257 170
".:in Ste m
Xsolation
. in= Leat' "a tee tots Cv Pri Containms nt 1,2,3 16 Amphenol 16 Amphenol MS3102-A-20-4F MS3102-A-20-4S 257'50 RHR H'e'at -Exc1i'Ins trumen tati:ori -: 1, Z,3 Disch Rad'on
6 2
2
":Amphenol*
Amphenol Amphenol
" UG.1.Z13/U.. -":-.. 1'85
.'.1.50 UG932/U 350
'150 UG260/U 185 150 tea ter
- -;:.fluent sea u l sOn
,1 Instrumentati,on 1,2,3 3
1 1
Amphenol Amphenol Amphenol UG1213/U UG260/U UG932/U 165 15':
18")
156 350 150 Reac Bldg Instrumentation 1,2,3 Closed Cool
':ater Effluent 3
1 1
Amphenol Amphenol Amphenol UG1213/U UG932/V UG260/U 105 1
1'50115 185 115
": CI Steam 'n"trumentation Lea'c -.Detectors',2) 3 16
'mphenol 16 "
Amphenol; 3106A-20-4P'102A-20-4S, 257*
" 550
<i X1 Leal:
Qe tee tors Xnstrumentation 1,2,3 16 16 Amphenol Amphenol 3106A-20-4P 3102A-20-4S 257*
550 1,213 1
Amphenol
- CXC Backu Test
- ontrol Center Fuel Pool '
-'nstrunientation 1,2.,3
. ':Amphenol, 1 coling 69-OB-10-15 257 Rept 69-OR16-105'-0100 257' 115 Plug 69-6R-16-10P
1See Part Xl, Section C
~
~
REVISION 1
.Pare IX Environmental Qualification of Electrical Connectors A.
Oxi inal Testin The original qualification tests (i.e., pressure, temperature)
W conducted on the Browns Ferry penetxations and associated connectors were described during a meeting with NRC representatives on November 16, 1977.
These tests did not include qualification for tne electrical
,,.connectors for 'the environment resulting fxom a postulated design basis
~
I event or accident outside containment.
3.
Steam Envixonment Test Based on the discussions held duxing the November 16, 1977, meeting and on the November 18, 1977, letter, TVA decided to conduct a supplemental environmental test on selected samples of tne electrical connector types used in containment in identified safety systems to determine if they
'I V
could continue to function in a steam environment'f a design basis event.=
These samples were taken from the plant stock of spares and were not thermally ox radiation preaged.
Attachment 1 describes the test pxoce-dures
- used, the-connector, samples
- tested, the teat facility, the environmental conditions used in the test, the electrical loaaings used; and'he test results..
The actual test conditions exceeded those that would be expected in the case. of an actual design basis
'event for Browns Ferry Nuclear Plant.. The electrical connectors.
satisfactorily passed the steam environment test.
The purpose of this test was to provide a xapid assessment of the performance in a steam environment of thc electrical connectors within primary containment.
REViSlON 1 C'.
Evaluation of Connectors Outside. Prim Containment The critical electrical connectors outside containment are those that are associated with the main steam;
- HPCI, and, RCXC leak detectors.'he postulated accident'nvironment temperature can exceed the design temperature of-these. connectors.
These are identified in. Table 3 with, an asterisk
(~),.
These circuits are provided to detect and initiate isolation signals in the event of a pipe break.
Since the signal to initiate isolation is set at 200 7 and is well below the design temperature of 257 7 for the'lectric'al connector's; these connectors will have'erformed their safety function before any potential environmental degradation.
These sensors and associated electrical connectors are not required to function following the initiation of the isolation signal.
D.
Evaluation of Radiation Effects The Physical. Science connectors, being an integral part of the penetration assembly',."were specified to withstand a-.nuclear radiation of 10 R/hr for a 40-year life.
The Bendix connectors are not part of the penetration assembly and therefore did not have a specified radiation life, in actuality, the threshold for damage of many organic materials generally mf
~." 8" is.greater than ZO R, with embrittlement beginning above approximately' five times this value, The integrated dose to affected connectors would not be expected.'o
- exceed, 10 R during the time interval in which they are needed following an.LOCA, and the exposure from operation to the
\\
present time is extremely small by comparison.
Therefore, radiation damage to these connectors is not a concern related to operation during the next few months.
The'ctual racia ion ef ects on the connector materials will be determined in the future additional tests specified in Section E.
BEViSiOif 1 E.
Future Additional Tests TVA intends to establish the qualified 1ife of all electrical. connectors both inside and outside primary containment used in safety-related circuits at Browns Ferry.,
Type testing will. be used to establish qualified life with the effects of thermal and radiation aging included.
Xt is anticipated that this portion of the program vill oe completed vithin 90 days.