ML20214H879
| ML20214H879 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 11/13/1986 |
| From: | Howard J TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML20214H850 | List:
|
| References | |
| C010603-SQN, C010603-SQN-R02, C10603-SQN, C10603-SQN-R2, NUDOCS 8612010077 | |
| Download: ML20214H879 (8) | |
Text
I TVA EMPLOYEE CONCERNS SPECIAL PROGRAN REPORT NUMBER: C010603-SQN REPORT TYPE: Sequoyah Nuclear Plant Element REVISION NUMBER: 2 TITLE: Bolting-Material Compatibility PAGE 1 0F 7 REASON FOR REVISION:
Incorporate SRP and TAS comments.
Revision 1 To update safety significance on Attachment A.
Revision 2 PREPARATION PREPARED BY-M'l et l-ll ] V6 7
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SIGNATURE DATE CONCURRENCES CEG-H:
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- DATE APPROVED BY:
N/A ECSP MANAGER DATE MANAGER OF NUCLEAR POWER DATE CONCURRENCE (FINAL REPORT ONLY)
- SRP Secretary's signature denotes SRP concurrences are in files.
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1-1 TVA EMPLOYEE CONCERNS REPORT NUMBER: C010603-SQN i*
SPECIAL PROGRAM REVISION NUMBER: 2 PAGE 2 0F 7 I.
INTRODUCTION This report addresses three concerns, IN-86-183-001, IN-85-021-X04, IN-85-824-001 and which were determined to be generic to Sequoyah Nuclear Plant (SQN) by the Watts Bar Nuclear Plant (WBN) Employee Concern Task Group (ECIG) evaluation.
These three concerns raised the issue of material compatibility, more specifically, the use of carbon steel bolts in stainless steel flanged connections including stainless steel valves.
II.
SUMMARY
OF PERCEIVED PROBLEMS Carbon steel bolting material was installed in stainless steel flanged connections including valves.
Replacement of carbon steel bolting was started in valves.but halted before all bolting replacement was completed.
III.
EVALUATION METHODOLOGY The issue (as stated in section I above) was made generic to SQN as a result of the evaluation made at WBN. The following evaluation process was used at WBN for the Material Compatibility Element Report.
A.
Reviewed Nuclear Safety Review Staff (NSRS) Investigation Report I-85-483-WBN which addressed the use of carbon steel bolts in stainless steel flanged connections.
Determined the thoroughness of the report with respect to how adequately the concern was addressed as stated by the concerned individual (CI),
and if sufficient documentation relevant to the concern was reviewed.
Also, determined if the report addressed the use of carbon steel bolting in stainless steel valves, as well as flanged connections.
B.
Reviewed applicable criteria to determine the bolting requirements for stainless steel components to include TVA-WBN Class A, B, and C systems.
Also researched records to determine if documentation had i
been initiated (i.e., nonconformance reports (NCRs)) to record any previous deficient areas with respect to the subject concerns.
C.
Interviewed cognizant individuals in responsible organizations at WBN to determine if they agreed with the findings in the aforementioned NSRS report and evaluated their input on the relevance of the report to stainless steel valves.
- Also, interviewed responsible OE and Design Services personnel to determine the requirements / design intent with respect to the subject concern.
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TVA RMPLOYEE CONCERNS REPORT NUMBER: 0010603-SQN SPECIAL PROGRAM REVISION NUMBER:
2 PAGE 3 0F 7 IV.
SUMMARY
OF FINDINGS A.
A detailed review of NSRS Investigation Report I-85-483-WBN, revealed that it was sufficiently comprehensive in that it addressed directly the subject concern and provided adequate documentation to verify the findings and conclusion.
It was also determined that the NSRS report could be applied directly to carbon steel bolting in stainless steel valves.
B.
A review of TVA General Construction Specification G-29M revealed that section 3.1.7.4 addressed stainless steel flanges but did not directly apply to stainless steel valves.
A review of BLN-NCR-59 revealed that it applied to an ASME Class III-3 stainless drain tank cooler which had carbon steel bolting in closure connections.
The disposition of the NCR was to "use-as-is" since the vendor had supplied the tank with the carbon steel bolting installed.
As stated in the NSRS investigation report, NRC-IE Bulletin 82-02, addressed a corrosion wastage problem with carbon steel bolting in systems where borated water was present.
This subject was also addressed in NRC Information Notice 80-27.
The correspondence listed below applies directly to carbon steel bolting in stainless steel flanged piping, valve and pump flange connections:
-Memorandum NEB 791030 108
-Memorandum SWP 791109 047
-Memorandum NEB 810521 264
-Memorandum NEB 820401 276
-Memorandum B45 860113 268 The summary of this correspondence is that carbon steel bolt degradation was identified / documented as a problem in borated water systems.
As a result, corrective action has been initiated to replace on a "no delay to schedule basis" carbon steel bolting in the affected TVA designed flanged connections during routine survelliance/ repair / maintenance activities.
To this end, ECN 3522 was written on September 14, 1982 to add bolt replacement criteria to mechanical B/Ms. However, in memorandum B45 860113 268 it was noted that considerable confusion had resulted in the original B/M changes in accordance with ECN 3522, so another ECN (6004) was initiated on January 31, 1986 specific bolting substitution guidelines.to clarify the wording and give more It should be noted that in Class B and C systems, the SA 193 Gr B7 carbon steel bolting was to be replaced with specific stainless steel bolting material.
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t TRA EMPLOYRE CONCERNS REPORT NUMBER: C010603-SQN SPECIAL PROGRAN REVISION NUMBER: 2 PAGE 4 0F 7 However, if replacement bolting was not immediately available, the SA 193 GR B7 carbon steel bolting was to remain installed.
This substitution is also addressed in the aforementioned NSRS report.
A review of the 47BN series of drawings for various piping systems and components revealed the following:
1.
For Class A systems, in all cases. SA 453 Gr 660 stainless steel material is specified for stainless steel flanged connections.
2.
For Class B systems, the note initiated per ECN 6004 is included which allowed substitution of SA 193 Gr B7 (carbon steel) for SA 564 Type 630 (stainless) if the latter was not readily available. The stainless bolting was to be installed on a "no delay to schedule basis" as a replacement when it
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became available.
3.
For Class C systems, if SA 193 Gr 87 was installed, it was to
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be replaced as detailed in item number 2.
t A review of vendor valve drawings (Westinghouse) for Class A 4
systems, check, globe, and gate valves was conducted.
Of 18 separate drawings reviewed at random, no Class A valves were found to be furnished with carbon steel bolting. Also, a review of I
approximately 20 Class B check, gate, and globe valve drawings was conducted with the same result--no carbon steel bolting was furnished for the flanged bonnet-to-body connection.
C.
The cognizant OE individual, who was the author of the memorandum referenced above, was interviewed.
He indicated that OE's intent i
of the memorandum was to include the valve body-to-bonnet bolted connection with respect to carbon steel bolting replacement.
j Their interpretation of the valve body-to-bonnet connection was that it was also a flanged connection.
He also provided (informally) documentation with respect to OE's position on carbon steel bolting l
used in stainless steel flanges and valves, i
The cognizant site Design Services represent ative was interviewed.
He concurred with the statement by OE that the valve body-to-bonnet connection was, in fact, a flanged connection and therefore, was addressed as requiring carbon steel bolting replacement in accordance with the correspondence in section IV, paragraph B, of this report. He also indicated that it was reasonable to assume that the bolt replacement addressed by the subject concern on stainless valves was a result of the carbon steel bolting replacement recommendations per the correspondence referenced in section IV, paragraph B, of this report.
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TVA EMPLOYEE CONCERNS SPECIAL PROGRAN REPORT NUMBER: C010603-SQN REVISION NUMBER: 2 PAGE 5 0F 7 D.
In preparation of the Subcategory Report " Bolting (Construction),"
which includes the issue addressed in this report, the DNE Supervisor--Nuclear Engineering Branch, Codes, Standards, Materials Corrosion, and Coatings--was interviewed and the subject concerns were discussed.
This individual is a member of the joint Atomic Industrial Forum (AIF) and Metal Properties Counsil (NPC)
Task Group on bolting. He was coeditor of the paper " Improved Technology for Celtical Bolting Applications," presented at the 1986 Pressure Yessels and Piping Conference and Exhibition and published by ASME (attachment B).
The paper summarizes industry-wide bolting failure experiences, the AIF bolting program, the result of the work performed under the AIF program, and the AIF program recommendations.
The AIF report documents detailed research on boric acid wastage of carbon steel bolts.
The essence of his comments was that, assuming an adequate preventative maintenance program, leakage of carbon steel bolted connections because of boric acid wastage will be detected prior to a significant loss of the pressure boundary.
Thus, the concern is considered to be a reliability issue rather than a safety issue.
However, no evidence of a systematic review of vendor qualified components on safety related borated water service systems was found for any TVA PWR plant that would ensure that all critical connections were identified.
In fact, the DNP procedure that will control the bolt replacement program at WBN specifically excludes vendor qualified components.
This exclusion is contrary to the DNE technical position memorandums and the documented scope of the industry-wide bolting wastage problem.
J E.
The Employee Concern Task Group (ECTG) investigation revealed that the use of carbon steel bolts on flanged connections in borated i
water service was common to SQN, as well as WBN.
'However, no ECTG evaluation of SQN was performed beyond the examination of documents pertaining to this issue.
None of the SQN documents examined addressed conclusively all the issues raised by these concerns.
particular, the SQN responses to IEB 82-02 did not indicate that In i
all vendor qualified components in borated water service were reviewed to determine if carbon steel bolts were used in flanged connections nor was there any evidence to suggest that SQN's maintenance program would be revised to incorporate the AIF bolting program recommendations.
Consequently, deficiencies may exist at SQN similiar to the deficiencies identified at WBN.
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TVA EMPLOYEE CONCERNS REPORT NUMBER: C010603-SQN SPECIAL PROGRAN REVISION NUMBER:
2' PAGE 6 0F 7 CONCLUSION
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-1.
There is evidence to support the fact that carbon steel bolting is to be replaced with stainless steel bolting in TVA-designed fitnged' connections where borated water la present, including bolted pipe to valve connections.
l-It is conceivable that the CI witnessed valve bolt change-out at WBN on TVAndesigned 4
flanges in borated water service and it is also c'onceivable that the change-out was halted before completion because:
All available replacement bolting material had been used--
a.
no more was readily available.
b.
Since the bolting replacement was on "no delay tofschedule basis," more critical work may have required completion
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and therefore caused the bolt chenge-out to be halted for I
an indeterminate period of time.
i 2.
A partial review of valve drawings and B/Ms revealed no Class A i,
systems where valves were furnished with carbon steel bolting, and in Class B and C systems, the use of carbon steel SA 193 Gr B7 bolting is acceptable and will only be replaced in borated water pressure boundary systems. According to the referenced t
correspondence in section IV, paragraph B, the SA 193 Gr B7 carbon steel bolting is even considered an acceptable substitute for the replacement stainless bolting until the latter can be installed in the Class B and C systems.
The statement by the CI may well be a true statement with respect to carbon steel bolted stainless steel valves and the CI may also have witnessed a bolt change-out in the subject valves at WBN.
However, based on the findings of this evaluation, the concern has not identified a condition adverse to quality. Also, this evaluation is in agreement with the findings of the NSRS Investigation Report I-85-483-WBN.
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3.
The evaluation and investigation of this element at WBN did not i
reveal a procedure or program providing for the systematic evaluation of vendor quallfled bolted closures or flanged connections used on borated water systems.
In addition, no evidence was found to indicate that the recommendations to be made by the AIF Bolting Task Force will be reviewed by the appropriate organization (s) and, where applicable, incorporated into the site maintenance program (s).
Further evaluation and corrective actions will be required to resolve these deficiencies for WBN and SQN (CATD No. 10603-SQN-02).
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TVA EMPLOYEE CONCERNS REPORT NUMBER: C010603-SQN SPECIAL PROGRAM REVISION NUMBER: 2 PAGE 7 0F 7 V.
ROOT CAUSE None VI.
CORRECTIVE ACTION Corrective action is to be provided by line organization.
VII. GENERIC APPLICABILITY The concerns comprising this issue were determined to be generic to WBN, SQN, and BLN based on the evaluation of the concerns at WBN.
.f 111 ATTACHMENT A -
REFERENCE - ECPS120J-ECfS121C TENCESSEE VALLEY AUTHORITY FREQUENCY
- REQUEST DNP - ISSS - RWM OFFICE OF NUCLEAR PONER PAGE T
EMPLOYEE CONCERN PROGRAM SYSTEM (ECPS)
RUN TIME - 12sSfe22 LIST OF EMPLOYEE CONCERN INFORMATION RUN DATE - 11/10/86 CATE00RYs CD CONSTRUCTION-PROCESS
$U8CATE00RY: 10600 BOLTING S
DENERIC H
APPL GTC/NSR$
P KEYWORD A CONCERN SUB R PLT 385W INVESTIGATION S
CONCERN KEYWORD 8 NUM8ER CAT CAT D LOC f&Q3 REPORT R DESCRIPTION KEYMORD C KETHORD D IN 021-XO4 CD 10400 N H8N NYYY N0 H8NP UNIT #1, STAINLESS STEEL VALVES SPECIFICATIONS 750052 REPORT (CHECK, OLOBE AND GATE VALVE $s DIFF ERENT $1ZES: 2"O AND UP) HAVE STUD 8 PIPING OLTS & NUTS SHOULD BE STAINLESS STEE VALVES L.
IN 1983 AND 1984, STEAMFITTERS S TARTED TD CHANGE OUT THESE CAR 80N ST EEL STUDS & NU15. THE CHANGE OUT WAS
$ TOPPED IN 1984 DEFORE ALL THE VALV ES HERE COMPLE1ED. VALVES WITH CARB CN STEEL STUDS & NUTS ARE NDH INSULA TED. LOCATIONS REACTOR SUIL DING, (A CCUMULATOR ROOMS) AND AUX 8UILDING U Ntf 1.
CI COVLD NOT RECALL SYSTEN 0 R VALVE NUMBERS.
1 824-001 CD 10400 N H8N NYYY NO UNIT 1. *ALL OVER" - STAINLESS STEEL DESIGN REVIEW T500T1 REPORT VALVES INSTALLED WITH CARBON STEEL CORRECT!vE ACTION STUDS THAT HAVE SINCE BEEN COVERED 0 PIP]NO VER HITH INSULATION, NO ACDITICNAL VALVES INFORMATION AVAILABLE.
IN 18S-001 CO 10600 N H8N NYYY 1-85-48S-W8N NO CARBON STEEL $0LTS ARE INSTALLED IN SPECIFICATIONS TS0129 REPORT STAINLESS STEEL FL ANGED CONNECTIONS.
NONCONFORNANCE AN EXAMPLE OF THIS CAN BE FOUND 14 PJPING UNIT 2 IN THE AUX BUILDING ELEVATIO FITTINGS N TIS' NEAR 13814 AND U.
GO A80UT 1 0' TO THE NORTH DOHN HALL TD A ROOM ON THE LEFt. AN EXAMPL E !$ A80VT 3' 0FF THE FLOOR ON SOME 6* PJPE.
IT EXISTS ALL OVER THE PLANT. C1 HAS N 0 ADDITIONAL INFORMATION. CONST DE PT CONCERN.
S CONCERNS FOR CATE00RY CD SU8CATE00RY 10600
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