ML20117M837
| ML20117M837 | |
| Person / Time | |
|---|---|
| Site: | Dresden, LaSalle, 05000000 |
| Issue date: | 12/05/1983 |
| From: | Spessard R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20114G054 | List:
|
| References | |
| FOIA-84-616 NUDOCS 8505170233 | |
| Download: ML20117M837 (2) | |
Text
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. - p ast UNITED STATES M/Z4 o,,
NUCLEAR REGULATORY COMMISSION g-REGIONlil 5-799 ROOSEVELT Ro AD g
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GLEN ELLYN, ILLINOIS 60137 p
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Decem'er 5, 1983 b
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~ MEMORANDUM FOR:
D. G. Eisenhut, Director, Division of' Licensing.
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FROM:
R. L. Spessard, Director, Division of Engineering
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SUBJECT:
USE OF PARTS AND. MATERIALS.0F INDETERMINATE QUALITY IN' SAFETY-RELATEDLAPPLICATIONS
- During recent. Region III inspections at the Commonwealth Edison Company (CECO)
Dresden 2-3 and LaSalle 1-2 Nuclear facilities, it was determined that parts and materials of indeterminate quality were being used in safety-related QW...
, applications. The specific instances were as follows:
Chevron-type seals made of teflon were used on the torus-to-dryvell F,
vacuum breaker valve shafts. These seals formed part of the reactor
- containment boundary.
J Dow Corning DC-111 grease was utilized to pack the Chevron-type teflon seal units on the torus-to-drywell vacuum breaker valve shafts. The-
-grease was used to aid in the passing of the local leak rate testing
.(LLRT). The grease was required due to the physical design configuration of the chevron-type seals.
Ethylene - propylene soft seat seals were used as seals on the 24-inch-feedwater check valves (containment isolation valves). The soft seals provided a part of the containment boundary.
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These items were purchased outside the-quality assurance program requirements applicable to safety-related structures, systems', and components at the facilities._ Qualification requirements were not recognized, specified, or verified by Ceco, and the seals or grease had not been qualified by the licensee,-prior to use, by testing or analyses after being procured as commercial grade, off-the-shelf materials.
s yThe Region III inspections revealed an apparent important, underlying cause f
'. for.the failure to properly recognize, specify, or verify the qualification of
@Y these. type materials. An engineering decision had been made based solely on the applicability of the ASME code (pressure bound"f craponent) requirements,
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.and those parts not designated as'ASME code affe'ais ; were not considered safety-related. The qualification requireme-in or he parts were then not appropriately specified. This engineering }e. 3 L>
.ppears to be an industry Practice which needs to be addressed by the 44C.
8505170233 840914 PDR FOIA BARFIEL84-616 PDR
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D. G. Eisenhut 2
It is,our understanding that NRR is presently addressing the qualification of mechanical equipment similar to the handling of the electrical equipment qualification program. The above examples emphasize the need for that NRR effort to ensure uniform industry understanding of mechanical equipment qualification requirements and the problems encountered at the Dresden 2-3 and LaSalle 1-2 facilities. We have provided two proposed IE Information Notices to IE for consideration.
Our understanding regarding these matters is that materials used in safety-related applications need to be fully qualified through approved design and procurement programs or through comprehensive testing or analyses prior to utilization. Since it is possible that we will continue to encounter the use
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~~,,, of'less-than fully' qualified materials in safety-related applications, we need LNRR guidance on how to handle those cases. We would appreciate receiving'"you E guidance as soon as possible and request that it include criteria for determining the impact of.the use of less than fully qualified materials on I
~the operability of safety-related equipment.
' Questions regarding these matters should be directed to Messrs. J. F. Streeter (FTS-388-5541) or D..R. Hunter (FTS 388-5555).
j
.R. L. Spessard, Director Division of Engineering
Enclosures:
1.
Proposed IE Information Notice-
-Failures'of Soft Seat Seals on Valves 2.
Proposed IE Information Notice-Use of Parts and Materials of Indeterminate quality in Safety-Related Applications cc w/encis:
P. Vollmer,' NRR R. Wessman, NRR A. Bournia, LPM, LaSalle
'R. Gilbert, LPM, Dresden J. Partlow, IE F. Jordan, IE W. Shafer, RIII T. Tongue, SRI, Dresden W. Guldemond, SRI LaSalle
. Director, DE, RI
- Director, DE, RII Directors, DRRPEP, RIV & RV l
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'ma nee UNITED STATES NUCLNAR RECULATORY COMMISSION
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f:S REGION 111 j
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OLEN ELLYN. ILUNOl$ 40137 NOV 2 51983 M5MORANDUMFOR:
E. L. Jordan, Director, Division of Emergency Preparedness.and Engineering Response, Office of Inspection and Enforcement FROM:
R. L. Spessard, Director, Division of Engineering, Region III
SUBJECT:
PROPOSED IE INFORMATION NOTICE: FAILURES OF SOFT SEAT SEALS ON VALVES
, Enclosed for your consideration is a proposed IE Information Notice regarding recent failures of soft seat seals of dual seated check valves at the LaSalle County Nuclear Station.
If you have any questions regarding the proposed notice, please contact Dorwin Hunter (FTS 388-5555) or Ned Choules (FTS 388-5561) of my staff.
A-f R. L. Spessard, Director Division of Engineering, Region III
Enclosure:
As Stated cc: RI, RII, RIV, RV R. Kiessel, IE l
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UNITED STATES NUCLEAR REGULATORY COMMISSION-0FFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 DATE IE INFORMATION NOTICE NO. 83-
- FAILURES OF SOFT SEAT SEALS ON VALVES Addressees:
i-All nuclear power reactor facilities holding an operating license (OL) or construction permit (CP).
Purpose:
This information is provided to inform licensees of an event at a boiling water reactor (BWR) where the soft seat seals,on feedwater check valves failed. Addressees are expected to review this information for applicability to their' facilities.
Descriftion of Circumstances:
In September 1983 Commonwealth Edison Company notified the NRC that the inboard feedwater check valves at the LaSalle County Nuclear Station had failed their local leak rate tests. These check valves had been modified
. prior to initial plant operation from a hard seat valve to a combination soft p
and hard seat by modifying the valve discs to allow installation of the i
additional soft seat seals.. The failure mode of these soft valve seals which were of a molded design has not been definitely determined. However, there appears to be three possible causes. First, sharp edges around the l-pressure equalizing ports located in the discs had cut the soft seal material l
in multiple locations. The sharp edges apparently had not been properly removed when the valve discs were modified. It is possible the local leak rate test air bypaased the seal completely through those cuts. Second, a possible cause is that when the faces of the-soft seals were machined for proper fit the machining may have affected their sealing capability. Third, the service conditions encountered by the valves during plant startup and j
shutdown may have damaged the soft seals. The original. soft seals were ethylene propylene rubber obtained through Anchor / Darling Valve Company from L
the Stillman Rubber Company.
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The damaged molded seals were replaced in September with new seals of an estruded-vulcanized design obtained through Anchor / Darling Valve Company from Stevens Associates. Grinding was performed on these seals at the site to
.obtain proper fit and the valves passed local leak rate tests. Since the cause of failure of the original molded seals had not definitely been deter-mined, the licensee agreed to perform a local leak rate test on the valves
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during a subsequent outage. On November 16, 1983, Commonwealth Edison Company informed the NRC that the check valves had failed the local leak rate tests.
Disassembly of the valves showed the soft seals had failed at the vulcanized joints resulting in gaps. The licensee plans to return to seals of the molded design and conduct augmented leak rate testing to assure continued seal operability.
Anchor / Darling indicated that the failure of the extruded-vulcanized seals resulted from improper vulcanizing of the seal joints. Anchor / Darling is also of the opinion that the problem is probably limited to one batch of seals and only affects the LaSalle Nuclear Power Station. Attached is an Anchor /
Darling document listing those nuclear plants which the company has provided valve seals and showing the dates delivered. All soft seals, initial and replacement, furnished by Anchor / Darling after October 1981 were the extruded-
, vulcanized type.
It is not known which of the vs/.ves listed in the attachment may have applications important to safety or which have the molded or extruded-vulcanized soft seat material at this time.
Attachment:
Anchor / Darling Experience i
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Anchor /Dar ing m
EXPERIENCE # ~ l
. r.e. i CHECK VALVES, WITH DUAL SEAT DESIGN Valve Description UTILITY - Installatien ANSI Oty Slas Pressure Design Class (#)
BOSTON EDISON 3 77 Pilgrim 1 4
18" 900 TDC CAROLINA POWER & LIGHT
- 9 79 Brunswick 1 & 2 2
J8*
900 TDC 3-80 Brunswick 1 & 2 2
18" 900 TDC COMMONWEALTH EDISON 8-80 La Salle 1 & 2 4
24*
1500 TDC NORTHEAST UTILITIES 9 80 Millstone 1 4
18*
1500 Swing Check I
NEBRASKA PUBLIC POWER 1-81 Cooper Nuclear 4
18" 900 TDC FLORIDA POWER & LIGHT 1 81 Turkey Point 2
2%~
150 Swing Check DUKE POWER 6 81 Oconee 6
24*
900 TDC PENNSYLVANIA POWER & LIGHT 6 81 ' Susquehanna 4
24" 900 TDC COMMONWEALTH EDISON l
6-81 La Salle 1 & 2 2
10*
150 T Globe
. VERMONT YANKEE NUCLEAR FOWER 8-81 Vermont Yankee 4
18-900 Swing Check TAlWAN POWER 10-81 Kuosheng 1 & 2 2
17 150 Y-Globe TVA 1 0-81 Sequoyah 1 & 2 4'
8*
150 TDC 4
8-150 TDC TVA 10-81 Watts Bar 1 & 2 4
8*
150 TDC 4
6*
150 TDC TAlWAN POWER 6 82 Kuosheng 1 & 2 2
3*
900 Swing Check ILLINOIS POWER 7 82 Clinton 2
18*
1500 iTDC 1
.C O u ;;if t.04
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- sTILITY - Instatistion ANSI Oty.
Slae Prassure Design t
Class (#)
CAROLINA. POWER & LIGHT
-e 7-82 Brunswick 1 & 2 2
8*
150 Angle Globe GEORGIA POWER 9 82 Hatch 1 & 2 2
20" x 16" x 20" 150
% Globe 2
10" x 8* x 10" 150-Y-Globe BOSTON EDISON 9 82 Pilgrim 1 1
2(T 150
% Globe Stop 1
8" 150
% Globe Stop SOUTHERN CALIFORNIA EDISON 9 82 San Onofre 1
2%*
150 T-Globe ARKANSAS POWER & LIGHT 11 82 Arkansas Nuclear One 2
4*
600 T-Globe PENNSYLVANIA POWER & LIGHT 12 82 Susquehanna 1
20" 150 T-Globe 1
10" 150 T-Globe LONG ISLAND LIGHTING 1-83 Shoreham 2
18*
150
% Globe 2
, 8*
150
% Globe WASHINGTON PUBLIC POWER
. SUPPLY SYSTEM 183 WNP 2 4
24" 900 Swing Check CONSUMERS POWER 1 83 Big Rock Point 1
10-1500 Swing Check DETROIT EDISON 2 83 Enrico Fermi 2 6
1 20" 150 Y-Globe 1
10" 150
% Globe 1
DUKE POWER t
2-83 Oconee 3
6' 630 Swing Check TVA 3 83 Browns Ferry 12 1500 Swing Check WASHINGTON PUBLIC POWER SUPPLY SYSTEM 4 83 WNP 2 1-1(r 150 TGlobe DETROIT EDISON 5 83 Enrico Fermi 2 2
24" 900 Swing Check 4
20" 900 Swing Check 2
12" 900 Swing Check j
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' CINCINATTl GAS & ELECTRIC 6 83 W. H. Zimmer 1
8*
150 T Globe 8 83 W. H. Zimmer 1
8" 1500 TDC DETROIT EDISON 10-83* Ertrico Fermi 2 1
4-900 Swing Check 2
1%"
900 Swing Check 9
A" 1An hinn c.h., k
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