ML20214A887
| ML20214A887 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 10/09/1986 |
| From: | SARGENT & LUNDY, INC. |
| To: | |
| References | |
| OL-I-ROREM-161, NUDOCS 8705190643 | |
| Download: ML20214A887 (7) | |
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SARGENT&LUNDY DESIG?. CONTROL
SUMMARY
ASSUM?TIONS AND PROCEDURES
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PROJECT NO. 4(AS/M UNIT NO.' l]h...
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T PAGE _9 0F CALCULATIONS NO.
/h. 3. l
_ REY. Y DATE 9-2M5 3
DESIGN PROCEDURES AND ASSUMPTIONS I
FOR THE EVALUATION AND CLAS5IFICATION
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OF DISCREPANCIES, CONCERN 5 AND 055ERYATIONS IDENTIFIED IN THE BRAIDItVUU CON 5TRUUIION A55E55 MENT PROGRAM (BCAP) s.
1.0 The purpose of this design control sumary (DCS) is to define the assumptions and procedures to be used for the classification and evaluation of BCAP discrepancies and concerns.
This DCS does not apply to the evaluation of NCR's generated in parallel with the BCAP discrepancy reports.
1.1 Objectives
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The objectives of the BCAP are to verify that structures, systems and components at Braidwood are properly installed and to provide assurances to the following areas:
)
A.
No programatic design significant problems exist in the
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construction of the Braidwood Station which have not been identified and addressed.
B.
On site contractor's procedures governing ongoing safety-related construction and quality assurance activities i
addressed all applicable design and regulatory requirements.
C J
C.
Significant corrective actions for past construction problems 2
were adequately implemented and documented.
Three elements of BCAP have been initiated to ensure that the above objectives are achieved.
A.
Construction Sample Reinspection (CSR) is the element of the program that is responsible for the reinspection of completed h
construction work and the review of construction documents.
w The reinspection and review are conducted on a sample basis.
The sample is based on a random selection from the entire population.
A secondary sample based on highly g
stressed items may be included as part of the sample.
This specialized sampling is chosen from items with higher stress
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or more importance to safety-related functions.
iii fR B.
l Q f Reverification of Procedures to Specification Requimments (RPSR) is the element of the program that reviews current J
R installation and inspection procedures which govern the S, g
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ongoing and future safety related. construction work.
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AP.004S71
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DESIGN CONTROL
SUMMARY
SARGENT &LUNDY ASSUMPTIONS AND PROCEDURES E
PRO 1ECT NO. $ $ $l UNIT NO. $ '.
j PACE l O OF CALCULATIONS NO.
/M, /
REV. 1 DATE 9-2.3-6 f cE C.
Review of Significant Corrective Action Programs (RSCAP) is the element of BCAP that reviews the implementation, methodologies and documentation associated with the significant corrective action programs initiated by CECO and the contractors since the fall of 1982.
RSCAP discrepancies are processed by BCAP/ Ceco and are not in the scope of this DCS.
1.2 Methods of Analysis Methods of analysis shall conform to unique Braidwood design criteria and procedures which exist for each given design activity.
This includes a
review of all applicable load combinations (SSE, OBE, blast, etc.) and any other criteria unique to each element.
Clear referencing of load
- sources, Support / connection / beam
- numbers, drawing
- numbers, discrepancy reports, revisions, and applicable allowable stresses are required in each detailed calculation.
When detailed calculations require design loads, Braidwood final loads should be used whenever possible. However, Byron final loads which were developed using the Byron /Braidwood enveloped response spectra may be used if Braidwood final loads are not yet available.
Evaluation of reported discrepancies will be performed in two phases to detemine their effects on plant safety.
O 1.2.1 Phase I g
ce The first phase will be a case-by-case engineering evaluation of discrepancies observed during BCAP inspections.
This is
.y an ongoing review which will be perfomed on each discrepancy a
as it is received by S&L.
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1.2.2 Phase II x
E Phase II will be perfomed once all observations for any given populat'.on have been evaluated by S&L.
It will consist of a trending review of all observations in a population to determine if programmatic construction discrepancies exist.
This second phase will also determine whether additional sampling plans or refinement in analysis methods am required.
j 2.0 Scope i
The scope of this DCS is limited to the evaluation and classification of discrepancies and concerns reported by the CSR and RPSR elements of BCAP.
AR004S72
DESIGN CONTROL
SUMMARY
SARGENT&LUNDY ASSUMPTIONS AND PROCEDURES E
PRO.IECT NO. 4 *ff 3/ UNIT NO. h
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PAGE ll OF CALCULATIONS NO. li 1. '
REV.
5 DATE 7* D "E 6 Observations shall not be considered unless they have been validated and reclassified as either a discrepancy or concern.
In the remainder of this DCS, " discrepancies," shall be taken to refer to both discrepancies and concerns.
2.1 Sample Population s.
Sample populations to be evaluated in full or part by the Structural Engineering Divis. ion will be limited to the following:
1.
Concrete placement 2.
Structural steel 3.
Masonry walls 4.
Condqit and conduit hangers 5.
Cable pans and cable pan hangers 6.
Electric equipment installation 7.
HVAC ducts and HVAC duct hangers 8.
HVAC equipment installation 9.
HVAC plenum fabrication l
10.
Mechanical equipment field fabrication 11.
Mechanical equipment installation 12.
Rigid and non-rigid large bore pipe supports 13.
Small bore pipe supports 14.
Instrument pipe / tube support 6
2.2 Sample Selection l
The selection of population items to be inspected is the j
responsibility of BCAP personnel.
The procedural description for sample selection is outlined in BCAp documents nos. 20 and 21.
9 Basically, the selection of elements to be inspected is based on N
statistical techniques for random selection from the entire J.,
population.
The selection of highly stressed elements is done by e
SED.
f 2.2.1 Highly-Stressed Elements Inspections on highly stressed elements may be included for some populations to provide a biased sample towards verifying non-design significant construction quality. Highly stressed populations are provided only at the request of the client.
Selection of highly stressed elements is based on the element's interaction coefficient as detemined in technical t
evaluation or final load check.
Elements with interactions i
of 0.8 or higher are considered highly stressed.
- However, t
the limit for critical interaction may be changed to provide a larger population from which the sample may be chosen.
In addition, the sample size may be increased by selecting i
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SARGENT&LUNDY ASSUMPTIONS AND PP,0CEDURES 5
paoaEcT so.q/g3f/ UstT No. /l2.
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I PACE l1 OF CALCULATIONS N0. __/9 3./
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elements which are i nportant to safety-related operations.
The total of highly stressed elements identified for each
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population shall be determined by the client.
2.3 Cable Pan Support Population For the cable pan support population, only checklist a ttriba tes involving weld quality dill be evaluated.
Configuration attributes for cable pan supports were deleted from the BCAP scope.
These attributes are inspected for hanger technical evaluation, and the inspection procedure in controlled by PI-BB-85.
1i 3.0 Evaluation o,f, Discrep,ancies, The evaluation of structural discrepancies is performed to determine if the discrepancy would have affected the item's ability to perform its safety related function and remain within code allowable stresses when subjected to as-built conditions.
The evaluations are categorized into i
four levels of capacity reduction determined by documentation, documented engineering judgement, or calculation analysis.
The discrepancy reports shall be divided into the following categories:
^tu)/ X-t ^, t taji) y X classification applies to ccmponents with 2
reported discrepancies that are within BCAP checklist tolerances or within specified S&L construction tolerances.
Items that are within BCAP tolerances cause the discrepancy to be specified " invalid" in Part 4 of the BCAP Observation Record (see Section 4.0).
Items that exceed BCAP C
g tolerances but are within specified S&L tolerances are specified as a
" valid discrepancy."
As-buil t conditions which have been shown by generic calculations to have no effect on the element capacity are also*
considered as Category X.
!!J, l Category Y - A Category Y classification applies to components with e
discrepancies that may be evaluated based on engineering judgement or enginerring calculations.
In all cases, items included in Category Y xg have reductions from zero up to and including ten percent when compared to the as-specified condition.
Engineering judgement as identified below allows for a comparison of the magnitude of the discaepancy with the original design or specifications. A discrepancy resolved by engineering judgement shall be considered to be within code allowables and able to meet its 1 cad carrying requirements.
Nonconfonning attributes that result from a deviation in a design drawing such that tne as-built condition is in excess of what is shown on the design drawing and has no impact on design requirements are included in this category.
All components have specifie! :yntties with inherent design margins.
/
Refined analysis, actual niteisl certificates, and actual applied loads are all methods to refine a calculation, should.one desire to remove l
AP.004S74 6
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DESIGN CONTROL
SUMMARY
SARGENT&LUNDY ASSUMPTIONS AND PROCEDURES E
PROJECT NO. /v483/34 UNIT NO. h j
C 21 ***-
l PAGE 13 0F CALCULATIONS NO. / 9. 3. l REV. 6 DATE I//B/$SS~
E additional design conservatism.
When the capacity of an item is reduced by less than 10%, it becomes apparent that the minor effect to the design margin may easily be offset by applying any of the calculation refinements available.
Therefore, engineering judgement that an item remains within design allowables may be applied to any item that retains at least 90% of its section.
Category Z
-A Category Z classification applies to components with reported discrepancies that result in a reduction greater than 10 percent when compared to the as-specified conditions and has an as-built interaction coefficient (IC) 4 1.0.
The method for evaluating the discrepancies is based on engineering calculation because the item's as-built condition cannot be judged adequate without a detailed calculation.
Discrepancies that have an insignificant effect on Category Z evaluations may be reclassified as Category Y for trending purposes.
Examples of these discrepancies are weld porosity, arc strikes and craters which considered independently would result in negligible capacity I
reductions.
This Judgement can only be applied for trending of discrepancies, and is not to alter the reported R-value of the evaluation which contains the insignificant discrepancies.
Category 0 - A Category 0 classification applies to components with as-built IC > 1.0, reported as design significant discrepancies.
Tnese are items, which uncorrected, could impair the items ability to perform its safety related function.
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3.1 Stress Transfer plane u
The discrepancy evaluation shall be performed to determine the j
reduction in capacity across the entire stress transfer plane.
The 7
stress transfer plane is defined as the load carrying mechanism for p
all normal and shear stresses occurring at the discrepant m
location.
The capacity of adjacent Stress transfer planes shall not g
be evaluated to determine which transfer plane is more critical.
o The stress transfer plane on which the discrepant condition is repo*ted shall be considered as the governing case.
i ARC 04S75
DES 2GN CONTROL
SUMMARY
SARGENT&LUNDY ASSUMPTIONS AND PROCEDURES E
PROJECT NO. 46 93pUNIT NO. jj]
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PAGE g 0F CALCUI.ATIONS NO. / 9. 3. /
REV.
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DATE //- //- fs-E 3.2 Reporting of Capacity Reduction The reduced capacity of an item due to the reported discrepancy is represented by the term "R."
This R value when determined by documented engineering judgement is generally the ratio of the as-built properties of an item to the as-designed properties of that item, and is a quantitative measure of capacity reduction due to the reported discrepancies. Category X components, which are components within specified tolerances, have no reduction in design strength, and, therefore, R equals 1.0 for all Category X discrepancies.
For components evaluated by engineering judgement, the R value must be greater than or equal to 0.90, where:
g verning properties of as-built component R = governing properties of as-designeo component In some cases, as-built conditions may result in larger components capacities than the as-designed component (i.e.,
R > 1.0).
For-these cases, R shall conservatively be reported as 1.0.
For discrepancies that result in a Category Z classification, the R value is the ratio of the as-designed stress interaction coefficient (IC) to the as-built stress interaction coefficient for the item under consideration.
For Category Z components, the. R value is given as:
R = g verning stress IC as-designed o
governing stress IC as-ou11t g'
The R-value determined by the Stress IC ratio may be greater than or equal to 0.90.
In this situation, the component is classified as
=
Category Y.
However, in no case shall a ratio of governing a
properties be used for a Category Z component R-value.
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3.3 Design Margin v2 5
The as-built design margin shall al so be calculated for all o
Category Z components. The design margin is a measure of the excess capacity remaining in the component, determined as the ratio of the design basis allowable stress to the actual as-built stress.
If this factor is equal to or greater than one, the design is within the specified design limits.
If the as-built stress IC exceeds 1.0 (Design Margin < 1.0), then the item has exceeded allowable stresses, and the discrepancy is considered Design Significant and is classified as Category D.
All discrepancies that do not cause the item to exceed allowable stresses are considered to be per Current Design Basis.
AP.004S76
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DESIGN CONTROL
SUMMARY
SARGENT&LUNDY ASSUMPTIONS AND PROCEDURES 5
PROJECT NO. 483/y UNIT NO. //Z
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I PAGE _/5_ 0F CALCULATIONS No.
19.3./
REV. I DATE //- Il-ff E
4.0 Discrepancy Reports BCAP CSR inspection checklists are used to reinspect completed construction work and construction documents for deficiencies.
If an attribute is found that appears to be in conflict with the checklist, the attribute is identified as an observation and a BCAP Observation Record, Form BCAP-06.1 (Figure 4.1), is, initiated.
Part 4 of Form BCAP-06.1 shall be initiated by S&L upon the completion of the discrepancy evaluation.
The following procedure shall be used:
1.
Enter observation number as listed on page 1.
2.
Complete the evaluation section of the form indicating the resolution of the discrepancy, including any design significance.
Root causes and programatic characteristics of an observation shall only be addressed on Part 4 if:
- 1) the root cause or programatic.
cnaracteristics occurred as a result of a deficiency in S&L specifications, drawings, etc.; and 2) the observation is design significant.
The root cause is the engineer's judgement as to the underlying cause of the discrepancy.
Whether this cause appears to be programatic or not should also be indicated.
Additional pages may be attached.
3.
Check the appropriate validity of discrepancy / concern and design significance box.
4.
Signatures and dates of the preparer and approver of the engineering evaluation, along with design calculation numbers are required for the completion of the form.
y 5.
Original forms must then be torwarded to the BCAP Administrative Engineer for final processing of the discrepancy.
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