ML20033A392
| ML20033A392 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 11/16/1981 |
| From: | Woolever E DUQUESNE LIGHT CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, 2DLC-4333, NUDOCS 8111250314 | |
| Download: ML20033A392 (5) | |
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United States Nuclear Regulatory Comission
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. Region I 631 Park Avenue Lj y,
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ATTENTION:
Mr. Boyce H. Grier,- Director A
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SUBJECT:
BEAVER VALLEY POWER STATION - UNIT NO. 2
-Docket No. 50-412 Motor Operated Gate Valves - Significant Deficiency 80-06
. Gentlemen:
This letter is interim report number 3 on' Significant Deficiency 80-06.
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On October 29, 1980, a significant deficiency of problems with three-inch gate valves manufactured by the Westinghouse Electro-Mechanical Division (W-EMD) was reported to the Nuclear. Regulatory Commission Region I office. Since that time, two interim reports were issued and some four-inch gate valves were also identified as deficient.
Recently, comnunication with Westinghouse and IE Bulletin No. 81-02, Sup-plement I have indicated that similar problems may exist in all W-EMD motor operated gate valves. The enclosed report describes the recent developments as they apply to Beaver Valley Unit No. 2.
This problem is still being investigated.
Duquesne Light plans to issue another report per the requirements of 10CFR50.55(e) when valve modification details are complete. This report is planned for June 1,1982.
DUQUESNE LIGHT COMPANY M
By E. J. Woolever Vice President Enclosu re cc:
Mr. V. Stello (15)
Director of Inspection and Enforcement Ms. Jane Grant Licensing Mr. G. Walton NRC Resident Inspector A
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i Interim Report No. 3 i*
Significant Deficiency 80-06 Westinghouse MOV Gate Valves 1.0
SUMMARY
IE Bulletin No. 81-02, Supplement No.1, stated that closure problems could be.
anticipated with the entire line of W-EMD manufactured motor-operated gate valves.
Several.of these valves are scheduled for installation on Beaver Valley Unit No. 2.
Attachment No. I t'o this. report lists the-valves identified as a result of this.
Bulletin Supplement that were not previously reported in earlier interim reports 'of i
Significant Deficiency 80-06.
2.0 IMMEDIATE ACTION TAKEN Nonconformance and disposition report 5029 has been prepared to identify and control all of the valves listed in Attachment No. I pending further investigation.
1
3.0 DESCRIPTION
OF DEFICIENCY As a part of its ongoing analysis program, Westinghouse Electro-Mechanical i
. Division (W-EMD) has applied the analytical methods developed for the 3" and 4" gate-valves to. the remaining W-EMD motor operated gate valves. These analyses predict that the entire line of motor-operated gate valves has the potential for not closing against dif ferential pressure.
4.0 ANALYSIS OF. SAFETY IMPLICATIONS The safety i=plications a re listed in the last colum of Attachment No. I titled " Consequences of Failure to Close."
5.0 CORRECTIVE ACTION TO REMEDY THE DEFICIENCY Westinghouse is conticuing the analysis of these valves to determine if each valve as currently built is capable of closing under its limiting normal and po'st accident service condition (" Final Functional Requirement" of Attachment 1).
For those valves which are incapable of meeting these requirements, Westinghouse will i
identify co rrec tive action to be taken to insu re that the valves close when required. The corrective action is expected to be complete by June 1,1982.
6.0 ADDITIONAL REPORTb
. A-final report will be issued when valve modification details are complete.
i t
9
'ATTACllMENT 1 P ge 1 t
INTERIM REPORT No. 3 SIGNIFICANT DEFICIENCY 80-06 Valve W-EMD Valve Location Model Maximum Dif ferential Pressure (PSI)
Function Numbe r Numbe r as Flow Approaches Zero Consequence of Failure to Close Equip.
Final Spec.
Functional Requirement VCT Outlet LCV-115C,E 4-GM72FB 200 100 Two valves in series; failure of either valve to close reduces redun-dancy of providing isolation. Alter-nate valve will provide isolation.
RWST to LCV-115B,D 8-GM72FB 200 200 One MOV in each of two parallel Suction of paths from the RWST to suction of Charging the CCP's; failure reduces redundancy.
Pumps of providing isolation of RWST during the recirculation phase following a LOCA.
Isolation will be provided by check valve in series with the two paths.
RCP Seal 8100 3-GM72FBil 200 165 Two valves in series; failure of Water 8112 either valve to close touuces Re tu rn redundancy of providing isolation.
(Containment Alternate valve will provide isolatiog isolation) i Charging 8130A,B 8-CM72FB 200 200 Two valves in series; failure of Pu mp 8131A,B either valve to close reduces Suction redundancy of providing isolation lleade r Alternate valve will provide isolatioI RilR Suction 8702A,B 12-GM88SEH 700 700 Two valves in series; failure of Isolation inner isolation valve to close j
(inner valves) reduces redundancy of providing isolaw l
tion. Isolation is provided by closing the outer valve.
RilR Suction 8701A,B 12-GM88SEli 700 700 Two valves in series; failure Isolation of outer isolation valve to close (outer valves) reduces redundancy of providing isola-tion. Isolation is provided by closin, the inner valve.
ATTA'CIIMENT 1 (CONTINUED)-
- E Valve W-EMD Valve Location Eodel
. Maximum Dif ferential Pressure (PSI)
Function Numbe r Numbe r as Flow Approaches Zero Consequence of Failure to Close Equip.
Final-Spec.
Functional Requirement l RHR Cold 8703A,B 10-GM88SEH 700 700 Valve in series with two check.
l Leg Discharge valves; no effect of valve failing l
to close.
Backflow into the RHRS -
l
~f rom the RCS is prevented by the.
l-ch,cck valves.
l l RWST to 8809A,B 14-GM72FB 200 100 Valve is closed ~ for recirculation l SI Pump phase following a LOCA.
If valve Suction fails to close, L kflow into RWST is prevented oy checi. valve in.line.
1.SI Pump 8888A,B 10-GM78FN 2750 200 When valves are used for containuent
~
l Cold Leg isolation:
Injection Containment isolation (ORC) valve.
Isolation of containment following failure of valve to close is provided by check valve (IRC).
When valves are used for switchover from cold leg to hot 1cg t rec irculatio@
Valve is closed for switchover f rom CL to HL recirculation.
Failure of valve to close will degrade flow to :
HL's.
Accunulator 8808A,B 12-GM88FNH 2750 u
Valve is closed to present-RCS Disc ha rge pressurization during - cold shutdown ope ra tions.
If the valve fails ~ to close, the accunulator may be depres-'
surized by venting the N2 to the-i conta inment.
Page 3'
' ATTACHMENT I (CONTINUED)
Valve W-EMD Valve L5 cation Eodel Maximum Dif ferential Pressure (PSI)
Function Number Numbe r as Flow Approaches Ze ro'-
Consequence of Failure to Close Equip.
Final Spec.
Functional Requirement Low Head SI 8887A,B 10-GM72FB 200 300 Failure of valve to close reduces ;
Pump Discharge
-redundancy of providing low head Cros sconnect y
train separation during CL recircu-lation phase following a LOCA.
Train separation can be achieved by.
- 3 [.
closing other valve, na e.-
Low Head SI 8889
' 10-GM78FN 2750 200 Valve is closed ' for switchover f rom Pump Discharge HL to CL recirculation following a 1
to Hot Leg LOgA.
If valve fails to close, iso-lation is provided by closing the LHSI discharge crossconnect valves.
Recirculation
-8811A,B 10-GM72FB 200 200 Valve is ' opened for recirculation Pump to Low phase following a LOCA and would be Head Safety closed for passive failure in the Jef t Injection rceirculation train. Following Header f ailure of the valve. to close, back-flow into the recirculation line is precluded by two check valves in the discharge. line.
Low Head 8812A,B 8-GM72FB 200-200
. Valve is1 opened for recirculation Recirculation
. phase following a'LOCA and would be to Charging closed for. an active or passive Pung Suction failure downstream of the valve (in the CCP train). Failure of the valve to close will not preclude isolation of CCP flow; flow will be stopped by shutting off the CCP.
.