ML20235L955
| ML20235L955 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 07/08/1987 |
| From: | Brown W, Russell Gibbs, Portwood G TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML20235L948 | List: |
| References | |
| CO11301-SQN, CO11301-SQN-R08, CO11301-SQN-R8, NUDOCS 8707170004 | |
| Download: ML20235L955 (20) | |
Text
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o TVA EMPLOYEE CONCERNS REPORT NUMBER: C011301-SON I
SPECIAL PROGRAM REPORT TYPE: Sequoyah Nuclear Plant Element REVISION NUMBER:
8 (Final Report) l TITLE: Design of Plates PAGE 1 0F 18
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REASON FOR REVISION:
i To incorporate comments Revision 1 To incorporate TAS and SRP comments Revision 2 To incorporate TAS, SRP, and NRC comments Revision 3 l
To update listing of concerns Revision 4 -
To incorporate SRP comments Revision'5 To incorporate line management' response Revision 6 I
and finalize report To incorporate NRC comments and refinalize report Revision 7 l
l-To incorporate additional NRC comments, evaluation Revision 8 findings and refinalize report.
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PREPARATION
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TVA EMPLOYEE CONCERNS REPORT NUMBER: C011301-SQN SPECIAL PROGRAM REVISION NUMBER:
8 PAGE 2 0F 18 I.
Introduction The concerns in this element, IN-85-031-001, IN-85-109-X04, OE-QMS-8, IN-85-033-001, and In-85-103-001 address the design of plates.
-1 II.
Summary of Perceived Problems The perceived problems address the following items:
A.
Errors, omissions, and incorrect assumptions were not corrected in design calculations.
B.
EnDes Procedure 4.03 Appendix 4, which addresses visual acceptance j
l of load additions to embedded plates (embeds), is not adequate.
j l
l C.
TVA is not in compliance with Nuclear Regulatory Commission (NRC) l IE Bulletin 79-02 in that base plate flexibility is not a design l
consideration.
j i
D.
Concrete anchor bolt load allowables for wedge bolt anchors are f
greater for Unit 1 than for Unit 2.
I III. Evaluation Methodology l
l l
A.
Reviewed the Sequoyah Nuclear Plant (SQN) Generic Concerns Task l
Force (GCTF) Report on " Inspection and Design Criteria Inadequate on Embedded Plates" for content, adequacy, and findings.
B.
Reviewed the Watts Bar Nuclear Plant (WBN). Employee Concerns Task Group (ECTG) Element Report on the Design of Plates (C011301) to determine generic applicability to SQN as well as content.
C.
Reviewed existing Nonconformance Reports (NCRs), Significant Condition Reports (SCRs), NRC IE Bulletin 79-02, Nuclear Safety Review Staff (NSRS) reports, Nuclear Engineering Procedures, Civil Design Standards, and other documentation and correspondence as required to determine applicability to the subject of this element.
D.
Interviewed knowledgeable personnel, as listed, to evaluate their input on applicable areas of the subject of this element.
Civil Design Analysis (CDA) engineer, SQN - Division of Nuclear Engineering (DNE); two Civil Design engineers. SQN-DNE; SQN Compliance / Licensing engineer; SQN Electrical Modifications engineer; DNE-SQN Engineering Project engineer; DNE-Civil Engineering Branch (CEB) Central Staff engineer; SQN Construction M & A Hanger Group Engineer.
TVA EMPLOYEE CONCERNS REPORT NUMBER: C011301-SQN SPECIAL PROGRAM REVISION NUMBER: 8 PAGE 3 0F 18 IV.
Summary-of Findings A.
A' detailed review of the SQN-GCTF report on Inspection and Design Criteria Inadequate on Embedded Plates revealed the following:
1 1.
The findings with respect to concern IN-85-033-001 were that EnDes Procedure 4.03, appendix 4, applied to WBN only..This evaluation agrees with that finding. The SQN-GCTF report also stated, "There are no issued. instructions for visual approval
)
of.FCRc due'to minor loads." This, however, is not:a.true statement. Construction Specification.N2C-937 (Locating Attachments on Embedded Plates) section 2.5.2, provides mechanism for visual' examination of embedded plates'by site OE personnel. This allows for approval of Field Change Reque'st (FCRs) without a sketch if the visual examination determines that detailed evaluation of the plate (calculation and analysis) is not required.
Discussions with responsible' i
engineers revealed.that the visual approval process allowed by.
l N2C-937 was not used at SQN.
Therefore, additional evaluation by the WBN-ECTG was performed and revealed significant details on this subject as described below.
A process is used by the Civil Structural' Design Group which l
allows for " preliminary approval" of minor loads attached to i
embeds.
This preliminary approval consists of engineering evaluation of the specific embed attachment by the responsible engineer. FCRs, Engineering Change Notice (ECNs), new j
attachments, alternate analysis review and revised loadings'per j
rigorous analysis are sufficient reason to initiate.this evaluation. A detailed sketch of the individual feature or attachment only is attached to a log sheet used for attachments to embeds. This sketch along with the information included on the log sheet provides sufficient detailed information for the responsible engineer' to evaluate the installation.:.For cases where minor loads are approved without detailed calculations being' performed,'a' note is made on the log sheet that only a minor load is invcived.
Subsequently, the assembled.
l information Ap-entered into'the group's computer data base which will establish a baseline of information for future i
reference.
Eventually, detailed calculations can be performed 1
on the emoed that will include the minor loads which receive only prelialnary approval under the current program.
I However, it should be noted that this program has been in place for approximately 6 months only. Therefore, only the deteiled calculations for each identified embed attachment submittf.d since the program's origination date and, future calculations i
for specific embed attachments will' be' retrievable from the data base.,.All other existing embeds, including attachment
.e L
z_-
.l TVA EMPLOYEE CONCERNS REPORT NUMBER: C011301-SQN SPECIAL PROGRAM REVIt'.ON NUMBER:
8 PAGE 4 0F 18 configurations and loads will not be included in the computer data base unless they are submitted to or identified by the group for evaluation.
It is reasonable to assume that the final contents of the data base will include only a portion of
.l the total number'of. embeds, their attachments and loads if the i
program continues in its present form.
Subsequent discussions i
with the responsible civil engineer in the group revealed that l
there were no commitments in place at present to perform j
detailed calculations / analysis on embeds which would include the loadings from minor load attachments currently receiving preliminary approval.
The process used by the Civil Support Design Group includes the following:
a.
A detailed sketch attached to the FCR which includes
. features within a 2-foot radius of the subject embedded plate attachment.
.i l
l b.
When applicable, a note is made on the FCR indicating.
minor loads are attached to the embed. While the minor load is shown on the detailed sketch, this load addition to the embed is not always included in the detailed calculations performed to qualify the embed.
- Instead, engineering evalustion by the responsible design engineer I
determines whether the minor load is significant to the point that it will be included in the detailed calculations.
l f
Both groups stated that there was no written criteria which l
clearly defined or provided guidelines for identifying minor loads.
Further discussion led to the conclusion that some general guidelines for identifying a minor load could further l
enhance the engineering judgment and expertise which is currently used to make this determination. This evaluation agrees with that conclusion.
i 2.
The SQN-GCTF report specifically addressed concern i
IN-85-033-001, but the information offered in Section III, 1 i
and 2 'is indirectly applicable'to concern IN-85-031-001Lwhich addressed errors, omissions, and incorrect assumptions in design calculations for structural steel access platforms. The SQN-GCTF report referenced Nonconformance Report - Generic Civil Engineering Branch (NCR-GENCEB) 8208, R3 which applies to j
multiple attachments to embedded plates; not to the description given above on concern IN-85-031-001.
However, NCR-GENCEB-8208 is indirectly applicable in that it, in conjunction with I
l l
L
___ _ ___- _ _ O
TVA EMPLOYEE CONCERNS REPORT EUMBLE: 0011301-SQN SPECIAL PROGRAM REVISION NUMFER:
8 PAGE 5 0F 18 NCR-GENCEB-8205 which addressed oafety factors for welded stud anchors for embedded plates (embeds), initiated a sampling program of 60 embeds which included independent reviews of existing calculations and visual checks of Field Change Request (FCR) sketches.
The sampling process also acted as a mechanism to reveal errors, omissions, etc., and revealed that all sampled supports exceeded the Design Standard (DS) in effect at that time (DS-C6.1).
The sample results reflected a confidence level of 95 percent that less than 5 percent of all embeds did not meet design requirements. The SQN-GCTF report also mentioned Project Construction Specification N2C-937 as being written to control field installations of multiple embed attachments at SQN when, in fact, N2C-937 was written as the
" Action Required to Prevent Recurrence" (ARPR) to NCR-GENCEB-8208, R3.
The NSRS Investigation Report I-85-265-WBN recommended that a procedure be issued to describe the actual embedded plate approval process:
N3C-928 was written for WBN and N2C-937 for SQN. The report concluded that the sampling program implemented according to NCR-GENCEB-8208, R3, verified the adequacy of embedded plates at SQN.
B.
A detailed review of the WBN ECTG Element Report for Design of Plates (C011301) revealed the following with respect to generic applicability to SQN:
1.
The generic applicability identified in the WBN report was addressed at SQN in SCR-SQNCEB-8607 R0, which applied to the distance between existing embeds and concrete edges.
This problem was identified as another part of the multiple attachment to embedded plate scenario originally addressed at WBN in SCR-WBNCEB-8623 and at SQN in SCR-SQNCEB-8622.
The sampling program initiated according to SCR-WBNCEB-8623 identified no plant hardware deficiencies but raised several
" side issues" which were documented as conditions adverse to quality (CAQ). Those determined to be generic to SQN will be addressed in Section IV.D.1 of this report.
SCR-SQNCEB-8607 is still open and will be addressed in Section IV.C.2 of this report.
C.
1.
A review of NCR-GENCEB-8208, R3 and the reply memorandum documenting the completion of the NCR (B41 850711008) was performed.
It was discovered that NCR-GENCEB-8205 was also addressed in the sixty plate sample that was done. The results of this cample revealed a 95 percent confidence level that less than 5 percent of the embedded plates sampled would not meet design requirements.
All welded studs analyzed had i
factors-of-safety which exceeded the design standard requirement.
TVA EMPLOYEE CONCERNS REPORT NUMBER: C011301-SQN 4
SPECIAL PROGRAM REVISION NUMBER:
8 PAGE 6 0F 18 2.
A review of SCR-SQNCEB-8607 which addressed the distance between existing embeds and concrete edges is still open. A summary of the actions being taken with respect to this SCR is as follows:
a.
A 100 percent review of all Type 2 embeds (DSC.1.8.1) is being done by the SQN Civil Design Analysis section.
b.
A " worst case" sample of embeds installed adjacent to concrete edges is also being performed at present. These actions are scheduled for completion before restart of SQN.
After restart, an upgrade of all Type 2 embeds to a higher factor-of-safety will be considered.
3.
Reviewed SCR-SQNCEB-8622 which addressed cable tray supports where all loading conditions may not have been considered.
This SCR applies to those embeds with cable tray supports attached and is still open and under review by Civil Design Analysis (CDA), SQN. Approximately 35 embeds are being reviewed on a " worst case" type basis; a load / configuration review was done to identify these embeds. The methodology being applied by the CDA at SQN is to sample different l
configurations from all Category I buildings to identify and correct cable tray support problems.
I 4.
a.
Reviewed NCR-SQNCEB-8404 which was written to document the failure to consider baseplate flexibility when determining anchor bolt loads. This SCR was initiated as a result of the Potential Generic Condition Evaluation performed by SQN in response to NCR-WBPCEB-8402 written at WBN which originally identified the same problem.
These NCRs were initiated because both WBN and SQN designers had misinterpreted previous design instructions for baseplate analysis which resulted in the DS-C1.7.1 Design Standard requirements not being fully implemented.
(A review of NSRS investigation report I-85-111-VBN revealed that TVA had not considered baseplate flexibility in baseplate designs as required by NRC IE Bulletin 79-02.
This evaluation agrees with that determination). TVA's response to the NRC's request for additional information on IE 79-02 (A27 800102006) included information on baseplate flexibility (Area 2.c.) and basically " wrote-off" the baseplate flex question.
Design Standard DS-C6.1 was in effect at that time and contained no criteria for consideration of baseplate flox.
Therefore, sample programs were initiated to evaluate base plates using flexible plate analysis.
Because of the similarity between WBN and SQN, as well as the fact that the nonconforming conditions were the same for both plants, a smaller samp]e l
TVA EMPLOYEE CONCERNS REPORT NUMBER: C011301-SQN SPECIAL PROGRAM REVISION NUMBER:
8 PAGE 7 0F 18 was justified at SQN (60 supports) since a 300 plate sample was performed at WBN.
The support sampling programs required recalculation of anchor bolt loads which would include baseplate flexibility. This exercise is still being performed and evaluated at SQN and NCR-SQNCEB-8404 j
remains open.
In addition, SQN will regenerate calculation packages for I
approximately 5600 seismic pipe supports on rigorously l
analyzed systems before unit 2 restart as required by NRC.
l This exercise will cause recalculation of the loadings or l
any concrete anchorages used in the affected pipe supports.
l It should also be noted that design standard DS-C1.7.1 1
requires baseplate flexibility to be considered in the i
calculation process when the baseplate does not meet the l
DS-C1.7.1 requirements for rigid plate analysis. Therefore, lR8 during the process of regenerating the aforementioned l
calculation packages, baseplate flexibility will be l
considered unless the affected pipe support baseplate (s)
I meet the criteria for rigid plate analysis. This exercise l
will serve to further verify that expansion anchor factors I
of safety meet the requirements of DS-C1.7.1 and NRC OIE l
Bulletin 79-02 when flexible plate analysis is performed.
l After unit 2 restart, calculation packages will be I
regenerated for affected pipe supports in alternately I
analyzed /small bore piping systems located in unit 2 and l
common areas.
I b.
The cer.cern expressed on wedge bolt load allowables (IN-85-109-X04) can also be answered by referencing the sampling programs initiated per SCR-SQNCEB-8404 for SQN and NCR-WBPCEB-8402 for WBN.
Since 79-02 increased the factor of safety for concrete anchors, this caused a reduction in the corresponding allowable bolt loads.
These changes occurred during a time frame which resulted in the al3owable loads for wedge bolts in WBN unit 2 being lower than those allowed in unit 1.
The same methodology was employed to establish wedge bolt load allowables both in units 1 and 2 at SQN and WBN unit 1.
This fact was verified during conversation with DNE-CEB Central Staff personnel. In addition, conversation with previous SQN Construction M&A Hanger Group personnel revealed that wedge bolts were used at SQN during this timeframe only as a replacement for SSDs which had failed the pull test required after installation.
Therefore, replacing a SSD with the same or larger size wedge bolt, as detailed in G-32, would serve to increase the overall factor of safety for the feature.
These facts are presented as evidence that the concern on wedge bolt allowable loads is not applicable to SQN.
TVA EMPLOYEE' CONCERNS REPORT NUMBER: C011301-SQM SPECIAL PROGRAM REVISION NUMBER:
'8 PAGE 8 0F 18 5.
A review of SCR-WBNCEB-8650 was performed to determine the
-parameters of the nonconforming condition identified at WBN on structural steel attachments to buildings and platforms.~ A search was made for the completed Potential Generic condition
' Evaluation' form which SQN was required to respond to as required by the SCR at WBN. It was. discovered.that SQN was still performing the evaluation to determine if the structural steel attachments to buildings and platforms were also nonconforming at SQN. This finding is discussed in greater
~
detail in Section IV.D.1, this report.
6.
A review of PIR-WBNCEB-8602 (initially referenced in the WBN-ECTG Element Report on Design of Plates C011301) revealed'
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the PIR to be closed. The Potential Generic Condition Evaluation performed at SQN as a result of the PIR at'WBN
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(Memorandum B25 860124 300) showed the identified condition (s) as being generic and NCR-SQNCEB-8502 had been initiated to document deficiencies in the following areas:
a.
inaccurate configuration in approval of FCRs b.
misinterpretation of installation requirements for;1-hole straps (47A056-2) rigid and rod type supports were mixed on nondivisional c.
conduit d.
supports installed using drawings not approved to qualified criteria The following actions were implemented on the items above:
Initial review of the condition adverse to quality (CAQ) on a.
inaccurate configurations being used in the approval of FCRs.has revealed this item'as not being significant to the point of preventing conduit from performing its intended design function. The program that will evaluate a sample of'the affected supports as' addressed in the subject NCR Engineering Report, to. determine their adequacy had not been initiated as of B-6-86.
~
b.
Initial review has revealed the' worst case failure to be slippage of the conduit through the clamps which would not cause conduit failure in most cases. Some over-tress'of the conduit could also occur but neither scenario would be likely to impair the overall functionability of the cable.
Therefore, a sample program.as recommended in the Engineering Report of NCR-SQNCEB-8502 R2 will be performed on the affected supports as well as a test program to~
verify the design adequacy-of the subject. clamps'. As of 8-6-86, the subject sample program had not been initiated.
?
TVA EMPLOYEE CONCERNS REPORT NUMBER: C011301-SQN SPECIAL PROGRAM REVISION NUMBER:
8 PAGE 9 0F 18 The evaluation performed on the mixing of rigid and rod c.
type supports on nondivisional conduit determined that localized support failures would not result in generic failure of conduit support mechanisms..In addition, the.
47A056-110 typical drawing provides mechanism for the-mixing of rigid and rod type supports under certain l
conditions. ~One specific condition involves the use.of flex type conduit between the rigid and rod type support.
Knowledgeable SQN-DNE' personnel who were interviewed were not aware of any instance where the flex type conduit had; not been used under the subject conditions. Therefore, it was concluded that mixing rigid and nonrigid (rod type)
I supports for nondivisional conduit would not prevent the conduit from remaining in place.both during and after a safe shutdown earthquake (SSE).
d.
Initial review, including detailed calculations, show all of the supports that attached to the steel containment vessel (SCV) meet category 1(L) criteria and all of the supports except one (support typical drawing 47A056-143) could be shown to meet the more stringent requirements of the SQN Pipe Support Design Manual without any structural modifications. The stresses in.the SCV meet the requirements of the ASME Code, section III under the effects of a design basis accident (DBA) and safe shutdown earthquake (SSE) loadings. Therefore, a small sampling program will be performed on affected conduit supports, to include evaluation of the as-built configurations, but had.
not been initiated as of 8-6-86.
This evaluation has performed a detailed review of the subject NCR and attached Engineering Reports. All-indications are that sufficient evaluations to include sampling programs will be performed to fully evaluate and determine the functionability of the subject conduit supports.
It was revealed that several areas of the aforementioned engineering reports lack definitive statements with respect to the adequacy of the conduit supports..However, when-j consideration is given to the fact that the engineering reports reflect only initial results based largely on engineering judgments and experience, the lack of definitive statements does not seem significant.
Section IV.E.5, this report, details further actions. required on this subject.
7 j
4 TVA EMPLOYEE CONCERNS REPORT NUMBER: C011301-SQN SPECIAL PROGRAM REVISION NUMBER:
8 l
l PAGE 10 0F 18
)
l 7.
A review was conducted of Nuclear Engineering Procedure (NEP)
L 3.1 (Calculations), 3.2 (Design Input). 3.3 (Internal. Interface Control), 5.2 (Review), and 6.1 (Change Control) to determine if adequate criteria existed to control the design processes used for calculations / analysis and the other' exercises associated-with these processes.
Also reviewed Modifications and Additions Instruction (MLAI) 11, R12 Section 7.5, and Design Standard j
(Civil) DS-C1.7.1.
To summarize the results of-these reviews, adequate controls and mechanisms are currently in place to.
control the design / analysis processes required at SQN, and to include sufficiently detailed check / review proceduresLfor eniculation packages.
8.
A review was performed of the SQN initial response to NRC IE Bulletin 79-02 and 79-02 R1 (A27 790705 010) and the SQN final l
responses to NRC IE Bulletin 79-02, 79-02, R1, and 79-02, R2 lR8 (A27 810403 011) and (NEB 810324 276). The NRC accepted-SQN's final 79-02 evaluation prt_ tam with approved deviations after lR8 l
l SQN answered additional.information requests made by the NRC subsequent to the initial response.
This evaluation has also identified a side issue relevant to the l
)
subject of concrete anchor qualification and NRC OIE Bulletin 1
79-02.
Specifically, it has already been stated that the NRC accepted SQN's final 79-02 evaluation program with approved.
I deviations. This acceptance occurred efter SQN had answered I
additional information requests from the NRC and is documented 1
in the SQN Safety Evaluation Report, Supplement 2, section 3.9.2, I dated August 1980, i
I However, further evaluation has revealed a discrepancy in the l
TVA response'to six additional questions posed by the NRC-l c?ncerning specific issues related to 79-02.
TVA memorandum l
NES 800201 250 dated February.1, 1980 documents the six-lR8 questions and the TVA response to each question.
Question l
three states, "For each type and size of expansion anchor used-l at SQN, provide a comparable table of the maximum allowable 1
design loads and the manufacturers' average ultimate strength l
values considering the actual concrete strength, embedment I
depth, plug depth and applied preload (as applicable)." The l
TVA response to this question included the requested table l
as well as the manufacturer's information on which the table' I
was based.
The response also stated, "Of the four manufac-l I
turers, Rawl is the only one who quotes capacities which are.
I consistently less than G-32 requirements.
In our opinion,'the l
lower Rawl test values are directly related to specimen size and I
testing procedure.
To the best of our knowledge, no Rawl i
self-drilling anchors were used at SQN..Rawl has not bid on
-l j
supplying any TVA project with self-drilling anchors and,-
l l
therefore, we have not tested any of their anchors." It has l
TVA EMPLOYEE CONCERNS REPORT NUMBER: C011301-SQN SPECIAL PROGRAM REVISION NUMBER:
8 PAGE 11 0F 18 been determined, however, that Rawl anchors were, in fact, used I
l at SQN.
I Therefore, DNE-CEB has initiated CAQR-SQF870101,. Revision 0, to I
document the.use.of Rawl self-drilling anchors at SQN. The CAQR l
description of condition states, "Rawl self-drilling anchors.
IR8 have been used at SQN. The manufacturer's data indicates
.I capacities less than the Phillips anchors used as the standard.
1 L
In addition.TVA's response to NRC OIE Bulletin 79-02 states I
that, "to the best of our knowledge no Rawl anchors were used at l
SQN."
This discrepancy was identified by an NRC inspector during i an audit of the Employee Concerns Task Group report on
.I anchorage."
(CATD C011301-SQN-09) l D.
1.
The responsible engineer, SQN Civil Design' Analysis Group, was interviewed and provided applicable information as detailed below:
- SCR-SQNCEB-8622 was applicable to cable tray supports only. He stated that the sampling program addressed in'Section IV.C.3, this report, had initially reflected positive results.
- SCR-SQNCEB-8607 was also an open iscue that was being reviewed by his group and addressed Type 2 embeds.as described in Section IV.C.2., this report. The SQN Po*.ential Generic. Condition Evaluation being performed as a result of SCR-WBNCEB-8650 was "to determine cumulative effects of attachments and configurations." The initial review indicated that the latest analysis criteria may.
not have been used in some cases.at SQN and all structural steel attachments may not have been considered. The review includes calculation packages and some "as-constructed" field walkdowns. PIR-SQNCEB-8658 has been initiated by SQN to document this potential deficiency. With respect to-the " side issues" raised at WBN as a result of SCR-WBNCEB-8623, the following comments were made:
At WBN some embedded plate FCRs reference the wrong unique a.
plate identification number. Reply:.SQN embeds were not assigned unique identification numbers like those at WBN so this problem was not generic to SQN.
SQN identified embeds-by location only.
4 TVA EMPLOYEE CONCERNS REPORT NUMBER: C011301-SQN SPECIAL PROGRAM-REVISION NUMBER:
8 i
I PAGE 12 OF 18 l
b.
At WBN attachments were identified which were not.shown on j
the latest embedded plate FCRs. Reply FCRs at SQN were evaluated one-by-one, each on a case-by-case basis so this problem also is not generic to SQN. Section d. below aisc 1
applies to this issue, Errors found in the calculations at WBN would be addressed c.
at SQN in the review required according to SCR-SQNCEB-8622.
d.
At WBN some embeddc.d plate FCRs were accepted using a standard review form.
Reply: This applies to WBN only
('
because SQN has never had and does not have now a standard review for FCRs. As stated in Section b..above, each is
' 1 considered on a case-by-case basis. Therefore, this problem is not generic to SQN.
]
With respect to errors, omissions, and incorrect e.
assumptions in the calculation / analysis process, he referenced the generic review that was done according to SCR-WBNCEB-8650 which would address directly the subject concern at SQN.
Preliminary results of the generic. review revealed potential problem areas with respect to all attachments to structural features not being considered.
PIR-SQNCEB-8658 has been issued for this problem. However, no instance of actual errors or omissions.in the calculation / analysis process had been identified.
He also indicated that human error was a reality that had to be considered in calculations / analysis but was' confident that-the new NEP described in Section IV C.7, this report,
~
3 i
l provided sufficient checks and balances to overcome this I
problem. His final comment was.that he was not aware of-any situation where identified errors had been left uncorrected.
l 2.
The responsible SC-4, SQN Civil Support Design Group, was-interviewed and indicated that she was not aware of any l
identified errors not being corrected.
Her response to the L
adeguacy of the new NEP as described in Section C.7, this l
report, was that it provided adeguate guidelines and controls for calculations and analysis in the design group.
j 3.
Several conversations with responsible engineers in the Division of. Nuclear Engineering (DNE), Civil Engineering Branch j
(CEB) Central Staff revealed the following:
The sample programs at SQN according to NCR-GENCEB-8208-
.j a.
included independent reviews of existing calculations'on embed attachments that would have revealed errors, omissions or incorrect assumptions as addressed in WBN concern IN-85-031-001. These independent reviews are considered to be important and are normally handled within the applicable group on a scheduled basis.
9 l
1
~
TVA EMPLOYEE CONCERNS REPORT. NUMBER: C011301-SQN
(
SPECIAL PROGRAM l
REVISION NUMBER:
8 l
PAGE 13 0F IS l
b.
As of July 15, 1986, 13 supports had been evaluated at SQN l
as a result of SCR-SQNCEB-8622 and none had failed. The D
initial sample included thirty cable tray supports that represented a " worst case" sample, The 100 percent review being performed at SQN according to c.
SCR-SQNCEB-8607 was scheduled for completion before restart. After restart, upgrading of Type 2 embeds (DSC'1.8.1) to a higher factor of safety will be considered.
With respect to section D.1.c. and e., this report, which address errors in calculations; this specific side issue applied to cable. tray supports calculations only and would be adequately addressed according to SCR-SQNCEB-8622.
d.
As detailed in Section IV.C.3.b. of this report, the concern on wedge bolt allowable loads was not applicable to f
SQN because the same methodology was used to calculate these loads for both Units 1 and 2.
The calculation process'and the allowable loads were not different for each unit as was the case at WBN.
E.
==
Conclusion:==
In view of the findings in Sections A, B, C and D, the following.
l conclusions are offered:
1.
Sampling programs have been performed or are being performed at j
SQN as a result of several SCRs, NCEs and Potential Generic Condition Evaluation reports. The sampling program that is
- i complete (according to NCR-GENCEB-8205 and -8208) revealed 95 percent confidence that less than 5 percent of the embeds did not meet the required criteria.
This statement-can be expanded by noting that the plant was never operated in an unsafe condition, nor was the actual structural integrity of-the embeds compromised with respect to each embed performing its intended function. This sample.would also have revealed j
errors,-omissions, etc. that were present in the existing initial calculation packages. The sampling programs in progress according to SCR-SQNCEB-8607 (Section C.2., this report). NCR-SQNCEB-8404 (Section C.4., this report)
SCR-SQNCEB-8622 (Section C.3., this report) and PIR-SQNCEB-8658 (Section D.1, this report) provide sufficient mechanism to address fully the concerns in this element.
1
,J TVA EMPLOYEE CONCERNS REPORT NUMBER: C011301-SQN-SPECIAL PROGRAM REVISION NUMBER:
.8 PAGE 14 0F 18 2.
Concern IN-85-031-001L wlII'be addressed directly atLSQN by-PIR-SQNCEB-8658.. The plant feature addressed by this PIR is structural steel attachments, the same feature identified in the employee concern. This PIR will also serve to identify errors, omissions.fand incorrect assumptions in the design calculations for these features.'
In addition, the existence of
~
I errors, omissions or incorrect. assumptions in design calculations, if any, will be revealed during the sampling.
programs and regeneration of calculation: packages at SQN.
Section 1 above gives summary information.with respect to the sample as well as specific sections-of this evaluation report which contain detailed information on the subject lof.each.NCR-and SCR.
Interviews with responsible personnel within the SQN site DNE organizations did not reveal evidence of. identified errors, omissions, etc., which would not have been corrected.
3.
Concern IN-85-033-001 was not answered adequately by the-SQN-GCTF report. This evaluation _ determined that the concern expressed on En Des Procedure 4.03 was not generic to SQN.
However, that portion of the concern which.specifically addressed minor loads attached to' embeds is. indirectly spplicable to SQN. It was determined that the programs,for evaluation of minor loads attached to embeds tre adequate with the.following comments:
a.
DNE-CEB should consider a review to determine whether general guidelines.for identifying minor loads would serve to improve the existing program (s).
An example would be i'
CEB-EP 21.46 which was issued at WBN to providefadditional guidelines for attachments to embeds not addressed in N3C-928.
b.
In addition DNE-CEB should consider a review to determine j
whether:
4
- The existing program (s) should be expanded so that the detailed sketch reflects all features attached to the embedded plate. This comprehensive' sketch would only be required the first time a FCR, ECN, new. attachment,-etc.,
caused the subject embed to undergo detailed
~
calculations. This exercise would serve to establish a baseline program which would preclude the potential for j
overloading an embed because all attachments had not been i
identified and considered during the calculation s
process.
Future FCR, ECN, etc. sketches would only be required to reflect the individual feature or attachment since the. data base would contain detailed calculation j
data on all other attachments to the subject embed.
l
L 1
l 1
IVA EMPLOYEE CONCERNS REPORT NUMBER: C0]I301-SQN t,
SPECIAL PROGRAM
(
REVISION NUMBER:
8 j
L
(
PAGE 15 0F 18
- Any mince loads receiving preliminary approval under the current program should eventually be included in the detailed calculation process.
Concern IN-85-103-001 and 0E-QMS-8 will be answered directly by
'4.
the evaluation of NCR-SQNCEB-8404 at SQN. This NCR addresses the issue of baseplate flexibility which was.a requirement i
according to NRC IE Bulletin 79-02.
The baseplate flex issue l-will also be addressed in the regeneration of calculation l
packages for seismic pipe supports before unit 2 restart as (R8-l l
l required by the NRC.
-l l
S.
The issues raised by NCR-SQNCEB-8502 R2 did not directly j
address a specific concern but did serve to identify problem j
areas within the subject of this element; Design of Plates.
The review of this NCR has revealed sufficient mechanism is'in L
place, i.e., detailed engineering evaluations, to include sampling programs, to insure complete resolution of specific problem areas.
However, section 5 of the subject NCR (NCR-SQNCEB-8502) which addresses the cause of the CAQ, details programmatic inadequacies as the principle cause of the identified deficiencies.
Additionally, SCR-SQNCEB-8607, NCR-SQNCEB-8404 and l
NCR-GENCEB-8205 were also initiated as a result'of programmatic inadequacies within the DNE organization. The most obvious inadequacies being the lack of consistency in the interpretation and application of design criteria at the site and engineering project level..
Therefore, DNE should consider implementing programs and/or exercises that will ensure all design personnel are adequately trained to applicable design criteria. This. training should be comprehensive and include upper-tier and site-specific design criteria as well as those site procedures, drawing notes, etc.,
which contain tolerances that, when applied.during the installation process by the site, could effect the original analysis / qualification basis.
6.
The " side issues" raised as a result of SCR-WBNCEB-8623 were determined not to be generic to SQN-(Section IV.D.1.a-e, gives-detailed information on this subject) except for the issue of calculation / documentation errors.
This specific issue is currently being addressed at SQN by several sampling and/or requalification programs as detailed in Sections IV.E.1 and 2 of this evaluation report.
I TVA EMPLOYEE CONCERNS REPORT NUMBER: C011301-SQN SPECIAL PROGRAM REVISION NUMBER:
8 l
PAGE 16 0F 18-l 7.
CAQR-SQF870101 documents the use of Rawl self-drilling anchors l
as well as the potential deficiency with respect to the '
l
)
qualification of these anchors.
Corrective action (s) are being
. l R8 l
developed by DNE-CEB. The CAQR process ls. sufficient mechanism l
I to resolve the identified deficiencies.
'l J
8.
The concern In-85-031-001 was verified as being true at WBN.
It was generically applicable.to SQN, and is being adequately addressed.at SQN.
The concern IN-85-033-001 was verified as being~true at.WBN but was not directly applicable to SQN.
The concerns IN-85-103-001 and OE-QMS-8 were verified to be true at WBN. They were generically applicable to SQN, and are being adequately addressed at SQN.
The concern IN-85-109-X04 was. verified to be true at WBN but was not applicable to SQN.
V.
Root Cause 1.
For NCR-SQNCEB-8404 - misinterpretation of instructions by designers for baseplate flexibility analysis and therefore, a failure to follow procedure (DS-C1.7.1).
2 For SCR-SQNCEB-8607 - failure to consider concrete edges on embedded plate capacities during'the design evaluation of,the plate and lack of adequate procedure.
3.
For SCR-SQNCEB-8622 - all loading conditions for cable tray supports were not considered in the original design and lack of adequate procedure.
4.
For NCR-SQNCEB-8502 - inadequate design criteria and implementation of requirements, lack of documentation, and lack of adequate training in the applicable design eriteria.
5.
For CAQR-SQF870101 - controls were not adequate to ensure that all~
l brands of concrete anchors vere qualified before use. Also, a i
failure to ensure that all correspondence on'79-02 issues was true-
.lRB and-verifiable by required documentation.
1.
I
L TVA EMPLOYEE CONCERNS REPORT NUMBER: C011301-SQN SPECIAL PROGRAM l
REVISION NUMBER:
8 PAGE 17 0F 18 l
l
)
l VI.
Corrective Actions The line management response to CATD Number C011301-SQN-03 was:
DNE-CEB does not'see the need to collect data other than that required to approve the attachment under evaluation.. By collecting data.in the immediate area of the subject attachment, enough data is obtained.to.
1 consider the effect of the subject attachment on the embedded plate including the effects of multiple attachments, G-32 violations'and location of the attachment on the plate.
The current design. method which utilizes data in the. proximity of the attachment effectively establishes a baseline concept because the-
]
results of previous qualifications are completed. Therefore, no action is required.
Further evaluation of the preliminary approval process by the WBN-ECTG I
has revealed this to be an acceptable practice. Therefore, this J
evaluation concurs with the line response.
The line management response to CATD Number C011301-SQN-02 was:
DNE-CEB will develop criteria to provide procedural control of the current preliminary approval program for attachments to embeds. This procedure will also:
- Provide general guidelines for identifying minor load attachments to embeds.
Require minor loads to be included in the final calculation process.
- Identify the methodology used to determine the final loading for each i
embed evaluated.
The line management. response to CATD number C011301-SQN-01 was:
'DNE-CEB will establish a program to ensure that DNE-CEB personnel are adequately trained in the application of design criteria and standards relevant to the work being performed.
These corrective actions are not SQN restart items.
i m
TVA EMPLOYEE CONCERNS REPORT NUMBER: C011301-SQN SPECIAL PROGRAM REVISION NUMBER:
8 PAGE 18 0F 18 The corrective actions for the listed CATDs are detailed below:
C011301-SQN Performance of disposition and subsequent closure J
of SCR-SQNCEB-8607.
{
C011301-SQN Performance of disposition and subsequent closure
)
of SCR-SQNCEB-8622.
C011301-SQN Performance of disposition and subsequent closure of NCR-SQNCEB-8502.
I l
C011301-SQN Performance of disposition and subsequent closure of NCR-SQNCEB-8404.
l Performance of disposition and subsequent closure j
C011301-SQN of PIR-SQNCEB-865'8.
l C011301-SQN Assignment and perforn.ance of corrective action and l
subsequent closure of CAQR-SQF870101.
l NOTE: This CATD issued for tracking purposes only.
\\
VII. Generic Applicability The issues raised by the concerns in this element potentially apply to all TVA nuclear plants. This determination was airo made by the WBN-ECTG Element Report on the subject of those issues. Design of Plates.
VIII. Attachments Attachment A Listing of Concerns Indicating Safety Relationship and Generic Applicability I
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