ML20041D564
| ML20041D564 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 02/26/1982 |
| From: | Mclendon C, Mclendon G LOUISIANA POWER & LIGHT CO. |
| To: | Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, W3K-82-0108, W3K-82-108, NUDOCS 8203050414 | |
| Download: ML20041D564 (3) | |
Text
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y 142 DELARONDE STREET POWER & LIGHT P O BOX 6008
- NEW ORLEANS. LOUIStANA 70174 * (504) 366-2345
$0$ s"04IU u
February 26, 1982 G. D. McLENDON Senior wce President W3K-82-0108 Q-3-A35.07.43 Mr. John T. Collins, Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76012
SUBJECT:
Waterford SES Unit 3 Docket No. 50-382 Interim Report of Significant Construction D.efic1ency No. 43
" Main / Emergency Feedwater System"
Reference:
Telecon - L. L. Bass (LP&L) to W. Crossman (NRC) on 1/29/82 O
Dear Mr. Collins:
In accordance with the requirements of 10CFR50.55(e), we are hereby providing two copies of the Interim Report of Significant Construction Deficiency No. 43, " Main / Emergency Feedwater System."
If you have any questions, please advise.
O C) g Very truly yours, NNlfgg h
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Attachment a
cc: 1) Director Office of orcement Washington, D. C. 20555 U. S. Nuclear i
ry Commission g[j\\
(with 15 copies of report) y M"IN Ph
- 2) Director
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1 Office of Management a
,f Information and Program Control U. S. Nuclear Regulatory Commission f
Washington, D. C. 20555 3 g @ g \\V] ] %
(with 1 copy of report)
I W-11982
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8203050414 820226 PDR ADOCK 05000382 S
PDR 1
LOUISIA'IA POWER 6 LIGHT COMPM;Y WATERFORD SES UNIT No. 3 Interim Report of Significant Construction Deficiency No. 43 "l'.AIH/DERGENCY FEED"ATER SYSTDi" Reviewed by hMMIW 4 / /9
- 2..
R. J. d'fihtz6er - Site Manager Date Reviewed by d,o) pe.c d//7!%2 J. 'L. Wills - Pget Superintendent
/ Date Reviewed by 2nw 4h [A
\\ N/9b1 J. Hard 6- @dj ect Licensing Engitieer J
I D' ate Reviewed by 6
'2/i5/p t J.
Kruin - ESSE'Woject Engineer
/
/ Date
~
[hS[92 Reviewed by O' le
/d/>_L d7J.Gutierrez-Q.A. S'ite Supervisor Date
/
February 10, 1982 t
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t
1 e
INTERIM REPORT OF SIGNIFICANT CONSTRUCTION DEFICIENCY NO. 43
" MAIN / EMERGENCY FEEDWATER SYSTEM" INTRODUCTION This report is submitted pursuant to 10CFR50.55(e).
It describes a design deficiency regarding the ability of the plant protection system to detect and to respond adequately to a break in the feedwater system piping inside containment.
The problem is considered reportable under the requirements of 10CFR50.55(e).
To the best of our knowledgs, this problem has not been identified to the Huclear Regulatory Commission pursuant to 10CFR21.
DESCRIPTION A review of the Main and Emergency Feedwater System has revealed that if a pipe break occurs in the feedwater line, inside containment, between the containment penetration and either check valve 2FW-V825A or 2FW-V826B, the Emergency Feedwater System (EFWS) may not perform as intended.
Upon a feedwater line break at the steam generator nozzle, the Emergency Feedwater Actuation Signal (EFAS) is actuated on low steam generator level in the intact unit.
A Main Steam Isolation Signal (MSIS) is generated upon low steam generator pressure. A " feed good generator only" logic is actuated by steam generator differential pressure. However, due to the presence of the check valves (discussed in the previous paragraph), there will be no large difference in pressure between the faulted unit and the intact unit when a break occurs upstream of the check valves.
This will prevent generation of the necessary signal required to isolate Emerge.tcy Feedwater (EFW) flow to the faulted unit. As a result, there could be excessive loss of emergency feedwater and an inability to maintain the secondary side heat sink.
SAFETY IMPLICATIONS Failure to achieve a pressure differential between the faulted and t'.ie intact steam generators results in a failure of the Emergency Feedwater System to p,erform as intended.
This loss of this system could adversely affect the safet/ of the plant.
Therefore, the present design of the feedwater system presents a safety hazard.
CORRECTIVE ACTION Corrective action for the feedwater design deficiency involves removing the internals of check valves 2FN-VS25A and 2FW-V826B.
This action would enable steam generator instrumentation to detect and respond to a feedwater break anywhere inside containment.
However, upon an Emergency Feedwater Actuation Signal (EFAS), these modifications could result in the loss of inventory from the intact steam generator through the break via a cross-connection in j
the EFUS.
To alleviate this, a 6"-900# check valve will be added downstream of each EFW flow transmitter.
FSAR Section 10.4.9.B, EFWS Reliability Analy-sis, will be updated to reflect the analysis of the failure of these valves.
Nonconformance Report W3-3444 was generated on February 4, 1982, to provide tracking on this deficiency.
Corrective action will be completed and a Final Report submitted to the USNRC by September 30, 1982.
s 2
LOUISIANA POWER & LIGHT COMPANY WATERFOPG SES UNIT No. 3 Interim Report of Significant Construction Deficiency No. 43 "MAIH/DERGD2CY FEED"ATER SYSTEM" Reviewed by hMMIW egl / /9
?.
R. J. di1@ flier - Site Manager Date Revieued by
.h_
d-r.s> pc.s-D//1fR2
/ Date J. 'L. Wills - Pget Superintendent Reviewed by (nw
+h
[A h/9!8 2.-
h J. Had E (ffdject Licensing Engitieer Date Reviewed by
'O~ h,,, n ik2L w
J.
ifruin - ESSE'Woject Engineer
/ 7Date Reviewed by Ot c[la
/84/1 f[/g / 92 Jj)J.Gutierrez-Q.A. Tite Supervisor Date
/
February 10, 1982 t
i i
[
s
4 g
INTERIM REPORT OF SIGNIFICANT CONSTRUCTION DEFICIENCY NO. 43
" MAIN / EMERGENCY FEEDWATER SYSTEM"
_. INTRODUCTION This report is submitted pursuant to 10CFR50.55(e). 'It describes a design deficiency regarding the ability of the plant protection system to detect and to respond adequately to a break in the feedwater system piping inside containment. The problem is considered reportable under the requirements of 10CFR50.55(e).
To the best of our knowledge, this. problem has not been identified to the Huclear Regulatory Comnission pursuant to 10CFR21.
L2SCRIPTION A review of the Main and Emergency Feedwater System has revealed that if a pipe break occurs in. the feedwater line, inside containment, between the containment penetration and either check valve 2FW-V825A or 2FW-V826B, the Emergency Feedwater System (EFWS) may not perform as intended.
Upon a feedwater line break at the steam generator nozzle, the Emergency Feedwater Actuation Signal (EFAS) is actuated on low steam generator level in the intact unit. A bbin Steam Isolation Signal (MSIS),is generated upon low steam generator pressure. A " feed good generator only" logic is actuated by steam generator differential pressure. However, due to the presence of the check valves (discussed in the previous paragraph), there will be no large dif ference in pressure between the faulted unit and the intact wait when a break occurs upstream of the check valves.
This will prevent generation of the necessary signal required to iso' late Emergency Feedwater (EFW) flow to the faulted unit. As a result, there could be excessive loss of emergency feedwater and an inability to maintain the secondary side heat sbak.
SAFETY IMPLICATIONS Failure to achieve a pressure differential between the faulted and the intact steam generators results in a failure of the Emergency Feedvater System to perform as intended. This loss of this system could. adversely affect the safety of the plant. Therefore, the present design of the feedwater systen presents a safety hazard.
CORRECTIVE ACTION Corrective action for the feedwater design deficiency involves removing the internals of check valves 2FN-VS25A and 2FW-V826B. This action uould enable steam generator instrumentation to detect and respond to a feedwater break anywhere inside containment.
However, upon an Emergency Feedwater Actuation Signal (EFAS), these modifications could result in the loss of inventory from the intact steam generator through the break via a cross-connection in the EFUS. To alleviate this, a 6"-900# check valve will be added downstream of each EFW flow transmitter.
FSAR Section 10.4.9.B, EFWS Reliability Analy-sis, will be updated to reflect the analysis of the fcilure of these. valves.
Nonconformance Report W3-3444 was generated on. February 4,1982, to provide tracking on this deficiency.
Corrective action will be completed and a Finah Report submitted to the USNRC by September 30, 1982.