ML20205D207
| ML20205D207 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 07/24/1986 |
| From: | Beck J TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | |
| Shared Package | |
| ML20205D198 | List: |
| References | |
| NUDOCS 8608150302 | |
| Download: ML20205D207 (10) | |
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i l COMANCHE PEAK RESPONSE TEAM RESULTS REPORT ISAP: I.a.5
Title:
NCRs on Vendor Installed Amp Terminal Lugs REVISION 1 rc ? /G sc ssue Coordinator Date b '
h Eview T p Leader Date' W . fLa.
JohK W. Beck, Chairman CPRT-SRT r/u/u Date 8608150302 860812
{DR ADOCK 05000445 PDR i
18 Revision: 1
- Pags 1 of 9 i RESULTS REPORT ISAP I.a.5 NCRs On Vendor Installed AMP Terminal Lugs
1.0 DESCRIPTION
OF IF7UE IDENTIFIED BY NRC (NUREG-0797, Supplement Number 7, Page J-30)
" Allegation AQE-36 involved vendor-installed AMP Product Corporation (APC) terminal lugs in ITT (sic) Gould-Brown Boveri, 6.9 Kv switchgear being excessively bent in the area between the ring and the barrel. The TRT discovered 16 NCRs (E-84-01066 through E-84-01081) issued early in April 1984, which documented this condition. The TRT review of TUEC action taken regarding these NCPs revealed the following:
- The NCRs described the APC lugs either as being bent in excess of 60 degrees or twisted.
- The documented record of a telephone conversation between TUEC and the representative of the lug manufacturer (reference letter VBR-16624) stated that lugs bent to 90 degrees one time were to be considered acceptable; that lugs bent to 120 degrees could be acceptable after utilizing an engineering evaluation by the end-user; and that although lugs bent to 120 degrees would not maintain their full mechanical strength, they would maintain their electrical characteristics. This acceptance criteria for field bent lugs was changed by APC due to the dispositioning of NCR E-84-00972 regarding the General Electric (GE) motor control center (MCC) thermal overload relay replacement program.
The TRT findings regarding the disposition of these NCRs were as follows:
- The disposition block of the NCR form stated that many of the lugs were " determined not to pose an equipment serviceability problem." However, there was no reference to or evidence of an engineering evaluation, as required by the lug manufacturer prior to a change in the acceptance criteria on NCR E-84-00972.
- Only the " bent" condition of the lugs was addressed by both the vendor representative and TUEC engineering.
Neither the mechanical strength nor the electrical characteristics were ever addressed with respect to
" twisted" lugs.
The TRT determined that these NCRs were improperly dispositioned in that the full scope of the identified problem was not addressed and the "use-as-is" dispositions were not adequately justified."
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j RESULTS REPORT l
ISAP I.a.5 (Cont'd) 2.0 ACTION IDENTIFIED BY NRC (NUREG-0797, Supplement Number 7, Item 6 (a), Page J-31)
"TUEC shall accomplish the following actions prior to (nel load:
Reevaluate and redisposition all NCRs related to vendce-installed terminal lugs in ITT (sic) Gould-Brown Boveri switchgear, taking into consideration the effects of twisted as well as bent lugs, and perform and document the results of engineering analysis to justify any resulting "use-as-is" dispositions."
3.0 BACKGROUND
The issue involved bending of AMP terminal lugs (also known as ring tongue terminals). In 1981, during the process of terminating (landing) conductors it became obvious that under certain configurations it was impossible to land conductors without bending the AMP terminal lug. Accordingly, Brown & Root Engineering contacted AMP Special Industries, a subsidiary of AMP Incorporated, t
for guidance on bending of AMP terminal lugs. The response (vendor letter VBR-16624), which formed the basis for acceptance criteria at CPSES, stated that AMP terminal lugs could be bent one time to 60*.
In the first quarter of 1984 when a GE thermal overload relay was being replaced, it was noted by TUGC0 that the AMP terminal lugs had to be bent 90* to 120* to install the relay. Because this violated the criteria for bending established in 1981, a Non-conformance Report (NCR E-84-00972) was issued. Shortly thereafter, during a scheduled TUGC0 QC inspection of ITE Gould-Brown Boveri Switchgear, it was noted that some of the vendor-installed AMP terminal lugs were bent in excess of 60*
and/or twisted.
j NCRs were issued to document the condition (NCRs E-84-01066 through i E-84-01081). These are the NCRs identified by TRT as giving rise l
to this issue.
In responding to the NCRs, in April 1984 AMP once again was contacted and the existing situation (including the criteria l established in 1981) was discussed. AMP responded that the terminal lugs could be bent two (2) times to 45' or one (1) time to 90*. Further, AMP stated that bending more than 90* and up to and including 120' is acceptable if the product user evaluated the specific application by considering the length of conductor to be i
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(Cont'd)
3.0 BACKGROUND
(Cont'd) l supported by the terminal and the susceptibility of the final installation to vibration. AMP also advised that, while a terminal lug bent more than 90* still maintained electrical characteristics, it would not maintain full mechanical strength. This information was documented in telephone conversation record CPPA 38,241, which was provided to AMP for review.
TUGC0 Nuclear Engineering (TNE) judged that the AMP criteria gave appropriate guidance to the concerns raised regarding bent and/or twisted terminal lugs. In applying these criteria, TNE decided that the terminal lugs in question would be replaced if the bending was in excess of 90* or the terminal lug showed signs of fatigue (i.e., flaking, cracking or other physical discontinuities).
At the time, TNE did not discuss the term " twisted" with AMP. This was due to TNE's evaluation that the term " bent" appropriately described the physical configuration of the small AMP terminal lugs and that TUGC0 QC's description of " bent and twisted" connoted a situation to which the AMP criteria applied. (As it turns out, anything other than bending requires excessive force and could not be done by hand. Terminal lugs described as being twisted were judged by TNE as being bent in a manner not exactly perpendicular to the axis of the terminal lugs, a condition consistent with physically landing the conductors by hand.)
Based on this information, the NCRs were dispositioned as follows prior to the TRT review:
- NCR E-84-00972 - An engineering evaluation was conducted by TNE as part of the NCR disposition approving bending the AMP terminal lugs associated with the GE relay in excess of 90' but less than 120'. (The TRT did not state any concern with this evaluation.)
NCRs E-84-01066 through 01081 - Each terminal lug in question had been inspected by TNE and where it had been documented that the bending had been in excess of 90* or the terminal lug showed signs of fatigue (i.e., flaking, cracking or other physical discontinuities), the terminal lug was to be replaced. The decision to replace all of the terminal lugs bent in excess of 90' had been based on the fact that it was not necessary for installation to bend the terminal lugs more than 90*, and replacing them would negate the need for an engineering analysis to justify their acceptance. However, the vast majority of the terminal lugs, including most noted
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ISAP I.a.5 (Cont'd)
3.0 BACKGROUND
(Cont'd) in the NCRs to be " twisted", had been dispositioned "use-as-is". The basis for the "use-as-is" disposition had been stated in the NCRs as follows:
"The current Manufacturer's position is that terminals may be bent one time to 90*, and up to 120* with engineering evaluation. Engineering has reviewed the following terminals in question .... It is our determination that these terminals do not pose an equipment serviceability problem and may be used as is."
Since the TNE disposition was that all terminal lugs bent greater than 90* were to be replaced, engineering evaluations were not required. (Note that TUGC0 QE approved the above disposition.)
While it was TNE's position that the stated dispositions were technically correct, and that the AMP criteria on bent terminal lugs encompassed the concerns regarding bent and/or twisted terminal lugs, the TRT was concerned that the NCRs did not clearly provide justification for the "use-as-is" disposition. To resolve its concerns, the TRT directed tha.t the NCRs related to the bent and/or twisted terminal lugs in the ITE Gould-Brown Boveri switchgear be reevaluated and redispositioned.
j 4.0 CPRT ACTION PLAN l 4.1 Scope and Methodology The objective of this action plan was to reevaluate and redisposition all NCRs related to vendor-installed terminal lugs in ITE Gould-Brown Boveri switchgear to take into consideration twisted as well as bent terminal lugs, confirm the accentability of the "use-as-is" dispositions, and have AMP substantiate their change in acceptance criteria.
The following tasks were implemented to achieve this objective:
- The sixteen (16) identified NCRs were redispositioned to justify the actual disposition.
- A vendor analysis of the bent and twisted terminal lugs was obtained.
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( RESULTS REPORT ISAP I.a.5 (Cont'd) 4.0 rTRT ACTION PLAN (Cont'd) 4.1.1 Disposition of Non-Conformances The Non-conformance Reports on bent and twisted terminal legs (NCRs E-84-01066 thru E-84-01081) were redispositioned. The redispositioned NCRs more clearly state the observed condition of the terminal lugs and the engineering justification for "use-as-is". The initial disposition of these NCRs did not allow any terminal lugs which were " bent or twisted" more than 90' to remain in service.
4.1.2 Vendor Analysis AMP was requested to and did provide documented analysis to substantiate the change from a 60* bend being acceptable to a 90' bend being acceptable. This analysis included an evaluation of " twisted" terminal lugs.
4.1.3 Use of Results If the results of this Action Plan had identified deficiencies in the "use-as-is" dispositions by TNE, then a root cause and generic implications evaluation would have been performed and appropriate corrective action determined.
4.1.4 Related Activities An evaluation of the dispositioning of NCRs including the adequacy of the technical justification is the subject of Action Plan VII.a.2, "Non-conformance and
,, Corrective Action Systems".
4.2 Participants Roles and Responsibilities The organizations and personnel that participated in this effort are described below with their respective work scope.
4.2.1 TUGC0 Comanche Peak Project 4.2.1.1 Processed NCRs identified in this action plan.
i l 4.2.1.2 Obtained AMP analysis of bent and twisted I
terminal lugs.
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. Page 6 of 9 i RESULTS REPORT ISAP I.a.5 (Cont'd) 4.0 CPRT ACTION PLAN (Cont'd) 4.2.1.2 Personnel Mr. W. I. Vogelsang TUGC0 Coordinator 4.2.2 Electrical Review Team 4.2.2.1 Reviewed the final disposition of the NCRs.
4.2.2.2 Reviewed the AMP analysis.
4.2.2.3 Performed root cause, generic implications, and safety significance evaluations, if required.
4.2.2.4 Personnel (prior to October 18, 1985) l Mr. M. B. Jones, Jr. Review Team Leader Mr. E. P. Stroupe Issue Coordinator 4.2.2.5 Personnel (starting October 18, 1985)
Mr. J. J. Mallanda Review Team Leader Mr. J. R. Pearson Issue Coordinator
- Mr. M. B. Jones, Jr.- Third-Party Adviser 1
! Mr. E. P. Stroupe Third-Party Adviser 4.3 Qualification of Personnel Third-party participants in the implementation of this action plan met the personnel qualification requirements of the CPRT Program Plan and its implementing procedures.
Other participants were qualified to the requirements of the CPSES Quality Assurance Program or to the specific l requirements of the CPRT Program Plan. Activities performed
! by other than third-party personnel were governed by the
! applicable principles of Section III.K " Assurance of CPRT Program Quality", of the CPRT Program Plan.
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Page 7 of 9 RESULTS REPORT ISAP I.a.5 (Cont'd) 4.0 CPRT ACTION PLAN (Cont'd) I 4.4 Procedures Not applicable 4.5 Acceptance Criteria The acceptance criterion is as follows:
The NCRs must be properly dispositioned by either justifying the "use-as-is" disposition or requiring replacement of the terminal lugs.
4.6 Decision Criteria The decision criteria are:
4.6.1 If the justification for using terminal lugs bent up to 90* can not be provided, they will be replaced. This was not necessary as described in Section 5.0.
4.6.2 If the justification for using twisted terminal lugs cannot be provided, they will be replaced. This was not necessary as described in Section 5.0.
5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS Each of the NCRs dispositioned "use as is" for bent and twisted terminal lugs in the ITE Gould-Brown Boveri switchgear was reviewed by TNE and redispositioned to provide a more complete justification for the "use as is" determination. Significantly, the TNE review reflected that no terminal lug originally dispositioned "use as is" showed signs of fatigue or was bent in excess of 90*. Accordingly, based on the vendor-provided criteria, the terminal lugs were acceptable without further analysis or rework.
AMP provided an Engineering Evaluation Report (including testing and analysis) supporting its 1984 position that bending an AMP terminal lug one time up to 90' was acceptable. This testing and analysis concluded that even with " moderate vibrations such as that set up by heavy equipment running, we feel that the testing proves that the terminations will withstand such a condition without any detrimental affects".- The ITE Gould-Brown Boveri switchgear 4
terminations are not installed near vibrating equipment and will
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Ravision: 1 Page 8 of 9 i RESULTS REPORT ISAP I.a.5 (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd) experience little, if any such vibration during their lifetime.
Also, a metallurgical analysis of bent or twisted terminal lugs was performed by AMP to demonstrate that the mechanical strength of the terminal lugs was not degraded in such a way that the seismic qualification of the terminal lugs was negated.
The AMP testing and analysis also reflected that terminal lugs twisted to 45' (approximately the maximum possible twist without risking damage to the terminal lug *) were acceptable given the "moderace" vibration described above.
The Electrical Review Team Leader (RTL) has reviewed the AMP Engineering Evaluation Report and associated metallurgical analysis and confirmed that the original qualification of the subject terminal lugs is supported by AMP for terminal lugs that are bent to 90* or twisted to 45*.
7 The Electrical RTL, using the redispositioned NCRs, performed an evaluation of the dispositions by a visual examination of all terminal lugs listed in the applicable NCRs written on the Unit 1 ITE Gould-Brown Boveri switchgear. All terminal lugs designated "use-as-is" were not bent more than 90* or twisted more than 45*.
However, some of the "use-as-is" terminal lugs appear to have been-replaced. The new terminal lugs also meet these criteria. One terminal lug (NCR E-84-01074, terminal lug attached to terminal point PR-1) was dispositioned by TNE to be replaced. Even though
! this NCR has been closed by QE, the RTL has concluded that this terminal lug has not been replaced. NCR E-86-100831S was issued by TUGC0 to document this deviation. Closure of this NCR will specifically be examined by the RTL in accordance with Section 7.0 below.
Since the "use-as-is" dispositions of the referenced NCRs do not involve any discrepancies, safety significance, root cause and generic implications evaluations were not performed. However, the deviation noted above on NCR E-86-100831S has been forwarded to the QA/QC RTL in accordance with Appendix B, " Quality of Construction and QA/QC Adequacy Program Plan," to be included in the collective ,
evaluations of that plan.
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- The Review Team Leader (M. B. Jones, Jr.) was informed by AMP that in preparing " twisted" specimens for testing, the maximum twist achievable without risking damage (e.g., cracking of the terminal lug's plating) was approximately 45*.
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- RESULTS REPORT ISAP I.a.5 (Cont'd)
6.0 CONCLUSION
S In April 1984 AMP advised TNE that bending up to 90* of the subject terminal lugs was acceptable. AMP further stated that bending from 90*-120* could be acceptable subject to an end-use engineering review. Prior to the TRT review, TNE determined that all terminal lugs that were bent in excess of 90* should be replaced.
The actions performed by CPRT, augmented by AMP's testing and analysis of bent and twisted terminal lugs, showed that the original dispositioning of the NCRs at issue was technically acceptable. TNE's decisions pertaining to the appropriateness of the April 1984 AMP criteria appear validated. The NCRs have all been redispositioned to provide a clear documented basis for acceptance of the existing equipment condition.
7.0 ONGOING ACTIVITIES Additional NCRs have been written by TUGC0 on bent and twisted lugs on various equipment in Units 1 and 2. TUGC0 has identified and will review the NCRs that were written prior to February 1,1986.
Any that have the "use-as-is" disposition will be evaluated to assure that all non-conforming conditions have been addressed and l
that required engineering justifications are adequate. CPRT will overview this activity and will issue a Supplementary Report when l
the overview is complete.
The deviation noted in Section 5.0 on NCR E-86-100831S was forwarded to the QA/QC RTL in accordance with Appendix B, " Quality of Construction and QA/QC Adequacy Program Plan," to be included in the collective evaluations of that plan.
The evaluation of dispositioning of NCRs including the adequacy of technical justification is the subject of Action Plan VII.a.2, "Non-conformance and Corrective Action Systems".
8.0 ACTION TO PRECLUDE OCCURRENCE IN THE FUTURE The installation specification (2323-ES-100) has been revised to incorporate criteria for inspecting vendor furnished terminal lugs.
This revision utilized the results of AMP's testing and analysis and provides assurance that bent and twisted terminal lugs will be appropriately addressed in the future on Units 1 and 2.
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