ML20212H378
| ML20212H378 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 12/17/1986 |
| From: | Beck J TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | |
| Shared Package | |
| ML20212H304 | List: |
| References | |
| NUDOCS 8701210379 | |
| Download: ML20212H378 (57) | |
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COMANCHE PEAK RESPONSE TEAM RESULTS REPORT ISAP:
II.c
Title:
Maintenance of Air Gap Between Concrete Structures REVISION 1 i
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/ A de Ishue Coordinator Datef /
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/ 2// 7 /JL JohyW. Beck,ChairmanCPRT-SRT Date l
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l 8701210379 870116 PDR ADOCK 05000445 A
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RESULTS REPORT ISAP II.c Maintenancs of Air Gap Between Concrete Structures
1.0 DESCRIPTION
OF ISSUE IDENTIFIED BY NRC Issue II.c was identified in SSER 8 (Reference 9.1, pages K-159 and K-160) as follows:
"The TRT investigated the requirements to maintain an air gap between concrete structures. Based on the review of available inspection reports and related documents, on field observations, and on discussions with TUEC engineers, the TRT cannot determine whether an adequate air gap has been provided between concrete structures. Field investigations by B & R QC inspectors indicated unsatisfactory conditions due to the presence of debris in the air gap, such as wood wedges, rocks, clumps of concrete and rotofoam. The disposition of the NCR relating to this matter states that the " field investigation reveals that most of the material has been removed." However, the TRT cannot determine from this report (NCR C-83-01067) the extent and location of the debris remaining between the structures.
I Based on discussions with TUEC engineers, it is the TRT's understanding that field investigations were made but that no i
permanent records were maintained.
In addition, it is not apparent that the permanent installation of elastic joint filler material ("rotofoan") between the Safeguards Building and the Reactor Building, and below grade for the other concrete structures, is consistent with the seismic analysis assumptions and dynamic models used to analyze the buildings, l
as these analyses are delineaced in the Final Safety Analysis Report (FSAR). The TRT, therefore, concludes that TUEC had I
not adequately demonstrated compliance with FSAR Section 3.8.1.1.1 [*], 3.8.4.5.1, and 3.7.B.2.8, which require separation of Seismic Category I buildings to prevent seismic interaction during an earthquake."
Cited in Reference 9.1, page K-160, as 3.4.1.1.1; corrected to 3.8.1.1.1 in accordance with Reference 9.1, page K-168.
2.0 ACTION IDENTIFIED BY THE NRC The actions to be taken regarding Issue II.c were identified in SSER 8 (Reference 9.1, page K-160) as follows:
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RESULTS REPORT ISAP II.c 4
(Cont'd) 2.0 ACTION IDENTIFIED BY THE NRC (Cont'd)
"Accordingly, TUEC shall:
4 1.
Perform an inspection of the as-built condatien to confirm that adequate separation for all seismic 4
category I structures has been provided.
2.
Provide the results of analyses which demonstrate that the presence of rotofoam and other debris between all concrete structures (as determined by inspections of the as-built conditions) does not result in any significant increase in seismic response or alter the dynamic response characteristics of the Category I structures, components and piping when compared with the results of the original analyses".
3.0 BACKGROUND
TUCCO has committed in the FSAR to provide separation between buildings to prevent unacceptable seismic interaction during an earthquake (see FSAR Sections 3.8.1.1.1, 3.8.4.5.1, and i
3.7B.2.8).
To meet this commitment, CPSES has been designed in a j
fashion similar to other nuclear plants by providing an air space between buildings wide enough to allow for building movement (sway) l' during seismic activity.
Structural drawings call out a " gap" of 2",
3", or more depending upon the buildings involved.
The air space is also referred to as a " gap", " seismic gap", " separation I
gap" or " air gap".
Certain components (e.g., fire or environmental seals) are by design allowed to span this gap. Elastic foam forming material is also allowed in the gap below waterstops'(below grade) in the design.
As construction commenced, an elastte foam
- was used by Brown &
Root as the concrete forming material. After pouring, the foam forming material was left in place. This practice continued until 1977, when it came to the attent. ion of Gibbs & Hill. Construction had been given Engineering approval to leave foam in place for pours below waterstops due to inaccessibility for i.
The use of the term " elastic foam" in this report is equivalent to the term "rotofoam" cited in NRC references (see Section 1.0 and
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O 2.0).
Rotofoam" is a particular brand of foam. CPSES has in fact used'a different brand of foam such that the term " elastic foam" as used in this report is appropriate.
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RESULTS REPORT O
ISAP II.c (Cont'd) 4 3.0 BACKCROUND (Cont'd)
I removal attempts [ documented in Request for Information or Clarification (RFIC) number C-029, January 29, 1976].
The approval was provided in Field Problem Action Request (FPAR) 110 (February 13, 1976). Apparently, Construction interpreted the Engineering response as a generic approval (i.e., for all elevations) and continued the practice of leaving foam in place. Gibbs & Hill learned of this practice in September 1977 and informed the Project th'at this deviated from the design concept.
TUSI meno TUS-5019 (November 2, 1977) instructed the Construction organization to remove the foam forming material so as to maintain the design air gap between the buildings in most locations.
As a result of this memorandum, slip-forming was subsequently used in most locations. Because most base mats and lower walls were already poured, this change primarily affected walls mere than 10 feet above grade.
Elevations at which foam was required to be removed were identified and Halliburton was contracted to effect removal. The inspection and documentation of this activity was
/N assigned to Brown & Root QC. Brown & Root QC developed a temporary
(_l procedure CP-QCI-2.4-9, " Inspection of Elastic Joint Filler Material Removal," which was limited to delineating the inspection and. documentation requirements for verifying the Halliburton work s
effort (removal of the elastic foam).
This procedure referred to TUSI memo TUS-5019 as defining the guidelines and scope of the removal effort and, hence, the scope for this one-time inspection.
A checklist was attached to this procedure (Inspection of Elastic Joint Filler Material Removal Checklist) to document the inspections performed.
To date, only two checklists that relate to the inspection scope have been identified. Both checklists were
! cigned on January 3, 1978.
A Gibbs & Hill meno was issued on January 30, 1978, stating that the gap areas identified in TUS-5019 were inspected by a TUSI Civil Engineer and a Gibbs & Hill Field Engineer, with the conclusion that the removal of foam for the identified areas was acceptable.
The Brown & Root Site Quality Control Manager issued a memo on February 19, 1978 (IM-12939), to the Construction Manager stating that inspections of the seismic gap between the Auxiliary Building and Containment Building #1 (part of TUS-5019 scope) were conducted to determine the effectiveness of the foam removal effort by Halliburton. This meno concluded that, based on the Brown & Root QC inspections, the foam removal efforts were incomplete and that further removal or engineering evaluation was required. A written reply to this memo was requested to define actions and schedule. A
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ISAP II.c (Cont'd) 1
3.0 BACKGROUND
(Cont'd) response from Construction management was apparently not provided.
It is not clear from IM-12939 whether the inspections referred to within the meno are the same as those done by QC inspection procedure CP-QCI-2.4-9.
The locations referenced in IM-12939 are different from those addressed in the two checklists discussed I
above that are identified with CP-QCI-2.4-9, although all locations are part of the scope defined in.TUS-5019.
Subsequent tc this activity, the QC procedures were revised to ensure that the seismic gap was in accordance with the design drawings at the time of concrete pouring. However, inspection reports subsequent to the removal effort have identified foam a
forming material and other_ types of debris in areas where the design drawings require air gaps. One of these reports indicated that the as-built gap was less than the design requirement. These e
reports (written in 1978) were attached to an NCR (NCR C-83-01067) i in April 1983 and sent to Civil Engineering for disposition. Civil Engineering closed out the NCR with a technical analysis which did i
not address the applicable FSAR load case combination.
The NCR has since been re-opened as Revision 1 as a result of the TRT investigation.
4.0 CPRT ACTION PLAN 4.1 Scope and Methodology i
The objective of this action plan was to assure that the condition of the air gaps between concrete structures is adequate to prevent significant interaction during a seismic event.
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The CPkT tasks that were implemanted to achieve this objective are:
l Provide initial as-built inspection of the condition of l
the seismic gaps to identify those areas which are not i
in compliance with the design drawings.
For all areas which do not comply with the design drawings, correct the condition and, where necessary, conduct en evaluation which demonstrates chat the condition meets the FSAR commitments.
Provide a final as-built inspection for all areas which required correction.
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5 RESULTS REPORT ISAP II.c (Cont'd) 4.0 CPRT ACTION PLAN (Cont'd)
Provide an analysis which demonstrates that any elastic material or debric remaining in the gaps does not result in a significant adverse effect on the seismic response of Category I structures, components or piping.
The following general sequence was used to resolve the issue:
Project QC inspections of the seismic gaps between-Category I structures and between Category I and non-Category I structures for both Unit 1 and Unit 2 were reperformed and documented. With the aid of special video recording equipment, Project QC inspected the existing conditions of the double-walled building separation gaps.* These inspections verified the separation gap width and located and identified the size and type of materials in the separation gap. A sufficient level of detail was provided from initial
!O, as-built inspections to support a decision to either remove existing debris or analyze its acceptability.
Inspections were also performed on single-walled building separation gaps ** which identified the as-built conditions, i.e. existence of elastic joint fillers, fire protection seals, flashing, etc.
These activities were overviewed by Southwest Research Ins'titute (SwRI), a third-party organization.
j The resulting as-built conditions were reviewed to ensure acceptability with design requirements.
Unacceptable conditions were noted to be corrected or analyzed to support the acceptability of the conditions.
Double-walled building separation gaps are separation gaps between two buildings that have a solid wall (except for openings from one building to the other) on each building face for the full height of a specific separation gap.
Single-walled building separation gaps are separation gaps between O
two buildings where one building has a solid wall (except for openings) for full height of a specific gap and the opposite building provides gap walls only at slab, beam, column, or wall ends.
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1 Page 6 of 56 RESULTS REPORT ISAP II.c (Cont'd) 4.0 CPRT ACTION PLAN (Cont'd)
The resulting as-built inspection documentation was reviewed with available construction documentation and past inspection records to assess the sequence of-events leading to the existing condition and the cause.
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Based upon the initial as-built inspection, a decision was made to either remove any debris encountered in the separation space through vacuuming or other methods or evaluate the significance of the as-built condition to the design basis.
[To date, corrective actions have removed all debris encountered.
Evaluations have been made as to the significance of material in the gaps required by design (e.g., fire seals) to tha design basis. Also, the Project has evaluated certain areas where inspection and corrective actions were considered impractical. The third-party has reviewed these evaluations and will review all subsequent Project f~s evaluations which justify excluding areas from corrective actions].
QC has documented and will continue to document the final as-built conditions and SwRI has overviewed and will continue to overview this process.
Engineering and QA/QC revised project procedures for establishment of requirements for maintenance of adequate separation conditions. The third-party reviewed the revised procedures.
Engineering evaluated the need to update the FSAR to reflect the as-built condition.
The third-party reviewed this evaluation and the ensuing FSAR change request and will overview any subsequent FSAR change requests or change request modifications that relate to the seismic gaps.
Engineering evaluated the cause of the existing condition and its applicability to other areas of the plant. Based upon these findings, a decision was made to expand the evaluation to include all seismic gaps and implement appropriate actions.
Issues relevant to construction housekeeping methods O
have been addressed as part of the response to NRC, January 8, 1985 letter on construction QA/QC issues (See CPRT Action Plan Number VII.a.7, " Housekeeping and System Cleanliness").
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1 Paga 7 of 56 RESULTS REPORT ISAP II.c (Cont'd) i 4.0 CPRT ACTIOM PLAN (Cont'd)
The third-party reviewed conclusions reached on cause and applicability to other areas.
The acceptability of the final as-built condition has been evaluated an'd will continue to be evaluated by the third-party.
The following action items were incorporated into the ISAP for 4
this issue but their completion has not been necessary so far to close this issue, for the reasons stated.
As necessitated by the results of the gap inspections, an analysis was to be performed using revised stiffnesses (or spring values) based on the actual characteristics and locations of the identified debris.
The re-evaluation was to determine the change in frequency from the original fundamental mode and to evaluate structural interaction effects. The significance of any change in frequency or interaction was to be determined as it applies to components and
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piping as defined in the decision criteria Section 4.6.
(To date, only two areas have been identified where it was considered impractical to search for and remove debris.
The Project has justified the exclusion of these two areas from the corrective actions program based on engineering evaluations, without the need of performing analyses - see Section 5.6.
These evaluations have been reviewed by the third-party.
Aside from these two areas, all debris encountered has been, or is being, removed. Accordingly, no analysis involving debris and its potential effect on building response has been necessary.)
The original analyses were based on clear gaps between the buildings; subsequently, Gibbs & Hill evaluated portions of the separation areas for the effects of the presence of clastic foam debris. These earlier evaluations (prior to CPRT), as well as any determined necessary as part of the effort described above, were to be subject to review by a third-party.
(The current corrective action plan calls for removal of all material in the seismic gap, both debris and seal material required by design, so that the gap condition can be verified to meet design requirements. Following this verification, seal material required by design will be reinstalled. Accordingly, previous Gibbs &
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Hill evaluations no longer reflect the as-built conditions, making third-party review unnecessary.
However, Project evaluations regarding material existing in the gaps by design will be reviewed by i
the third-party.)
i Engineering issued necessary instructions for removal of debris which significantly impact the original design calculations or removal of debris where this course of action is determined to be more expedient than analytical investigation.
(The significance of I
identified debris has not been analytically determined because of the Project decision to remove debris.)
After receipt of QC documentation verifying removal and the final as-built condition, the engineering calculations performed as part of this action plan will l
be revised as necessary to reflect the final as-built conditions.
(To date, no calculation revisions have been re, quired baseo on final as-built conditions.)
4.2 Participants Roles and Responsibilities The organizations and personnel th'at participated in this effort are described below with their respectiva scopes of work.
4.2.1 TUG 00 Nuclear Engineering (TNE) - Civil / Structural Discipline 4.2.1.1 Scope Coordinated as-built inspections and performed evaluations to determine removal requirements Assisted design engineer in final analysis and conclusions Issued design changes as required to document permanent items remaining in gaps; dispositioned Non-conformance Reports (NCR) j relating to this matter p
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RESULTS REPORT N--
ISAP II.c (Cont'd) 4.0 CPRT ACTION PLAN (Cont'd) 4.2.1.2 Personnel Mr. C. R. Hooton TNE Civil / Structural Discipline Supervisor Mr. M. Wells Engineering Specialist Mr. R. Orr Project Consultant 4.2.2 Gibbs & Hill, Inc., New York, N.Y.
4.2.2.1 Scope Performed calculations for effect of the as-built conditions on the seismic response and structural behavior O
4.2.2.2 Personnel Mr. E. L. Beskor Structural Job Engineer Mr. A. M. Kenkre Structural Squad Leader 4.2.3 TUGC0 Quality Assurance 4.2.3.1 Scope Inspected seismic gaps for compliance with design requirements and documented findings Documented general debris location and type before or during debris removal Documented final as-built condition 4.2.3.2 Personnel
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Mr. P. Halstead Quality Control
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1 Page 10 of 56 RESULTS REPORT ISAP II.c (Cont'd) 4.0 CPRT ACTION PLAN (Cont'd) 4.2.4 Brown & Root, Inc.
4.2.4.1 Scope Prepared areas for QC Inspections and provided Craft support as required for implementation and completion of CPRT Action Plan for this issue Removed debris as directed by engineering Installed required seals upon completion of verification activities 4.2.4.2 Personnel Craft personnel as required.
Protopower-Bisco 4.2.5 Third-Party Overview 4.2.5.1 Scope Performed review of Project calculations prepared in support of this ISAP Overviewed inspection activities Reviewed inspection documentation Evaluated overall conclusions Prepared Results Report 4.2.5.2 Personnel Mr. H. A. Levin TERA, CPRT Civil / Structural Review Team Leader A
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1 Page 11 of 56 RESULTS REPORT ISAP II.c (Cont'd) 4.0 CPRT ACTION PLAN (Cont'd) 4 Dr. J. R. Honekamp TERA, TRT Technical Manager Mr. J. C. Miller TERA TRT Iisues Manager i
Mr. P. L. Turi TERA, Issue Coordinator Mr. G. Lagleder So2thwest Research Mr. W. Weis Institute (SwRI) 4.3 Personnel Qualification Requirements Third-party participants in the implementation of this Action Plan meet the personnel qualification and objectivity requirements of the CPRT Program Plan and its implementing procedures.
The Brown & Root QC inspectors performing the separation verifications were trained in the applicable requirements of procedure QI-QP-11.0-3, "Concre.te or Mortar Placement Inspection". The minimum QC cercification level necessary-for this activity was Level I.
The inspectors used to implement this Action plan were not involved in previous separation verifications (i.e., verification of Halliburton foam removal effort in late 1977/early 1978).
Southwest Research Institute (SwRI) conducted a third-party overview of the Project QC inspection effort. The SwRI personnel were certified through SwRI's QA program, and were indoctrinated to the SwRI surveillance procedure (Reference 9.2).
Other participants have been qualified to the requirements of the CPSES Quality Assurance Program or to the specific 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.
4.4 Procedures
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QC inspections were performed in accordance with procedure QI-QP-11.0-3 and associated operational travelers for Unit 1 and Unit 2 areas. This procedure provided criteria for
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1 Page 12 of 56 RESULTS REPORT ISAP II.c (Cont'd) 4.0 CPRT ACTION PLAN (Cont'd) inspecting separation dimensions, documenting material remaining in the gap, and maintenance of the inspected ~
conditions. Results were documented on Inspection Reports.
Craft prepared areas for inspection and subsequent removal of debris.
Existing site procedures were used fcr these activities, Timarily issuance of inspected Item Removal Notices (IRN) for removal of permanent. seals.
SwRI conducted an overview of the inspections performed per QI-QP-11.0-3.
The overview scope and methodology was defined in SwRI surveillance procedure (Reference 9.2).
I 4.5 Standards / Acceptance Criteria 4.5.1 All air spaces are acceptable per the FSAR provided that there is sufficient space to prevent contact when s
structures experience deflections as a result of a l
seismic event (FSAR Section 3.7B.2.8).
The minimum gap required is defined in design calculations that meet the FSAR commitments.
4.5.2 Certain components (e.g., fire or environmental seals and elastic foam below waterstops) are by design allowed to remain in the gap provided it is demonstrated that the component's functionality is not adversely compromised and that the component does not adversely affect the structures forming the gap.
4.5.3 For any areas of gaps identified to contain debris that is not accessible for removal, the existing condition will be considered acceptable only if an engineering evaluation determines, based on the type, size and location indicated on the inspection reports, that seismic separation is not compromised.
(There have been no situations to date where debris that has been identified could not be removed.)
4.6 Decision Criteria The engineering analysis for the final as-built condition will document the degree to which materials remaining in the seismic gap (e.g., fire and environmental seals) may affect I
dynamic response characteristics of the structures.
If the engineering analysis reveals a significant modification of response, the response will be quantified by analysis and
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RESULTS REPORT ISAP II.c (Cont'd) 4.0 CPRT ACTION PLAN (Cont'd) response values will be compared to the original response values for determining separation acceptability. Upon
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evaluation of any significant change in frequency and structural behavior as compared to the original values, the necessity for further evaluation of components and piping will be considered.
(Corrective actions performed to date have caused removal of all debris encountered. Accordingly, no
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engineering analysis such as described above has been necessary. Analysis has been performed with respect to material in the gaps that is required by design. The above decision criteria have been applied to these analyses.)
5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS An index to the action items identified for this issue and the subsections in which they are discussed is presented in Table 1.
O The chronology of events related to the gap issue up to the TRT investigation is presented in Table 2.
5.1 Development of Seismic Cap Inspection and Maintenance Procedures I
The first step in implementing the action plan was development of procedures for the inspection of all seismic building gaps.
The location and identification of the major buildings is shown on the plan view presented in Figure 1.
An existing TUGC0 QC procedure, " Concrete or Mortar Placement Inspection" (QI-QP-11.0-3, Revision 4), was revised to add a listing of the seismic gap boundaries, inspection l
requirements, and guidelines for maintenance of the required l
gap during and after cleaning and verification.
The gap boundaries to be inspected using QI-QP-11.0-3 were initially identified from the listing of seismic Category I i
structures provided in FSAR Section 3.2 and by noting from arrangement drawings the interfacing seismic gaps between j
these structures. Also included were interfaces between seismic Category I structures and non-Category I structures (e.g.; Control Building / Turbine Building). Two additional seismic gaps were incorporated into the scope of this action plan as a result of the Critical Spaces Program, a task that ON is part of the VI.a Action Plan (see ISAP VI.a, " Gap Between the Reactor Pressure Vessel Reflective Insulation and the Biological Shield Wall", Section 4.1).
These are:
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ISAP II.c (Cont'd) 5.0- IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd) the gap between the Containment shell and its internal structure, and the top of secondary walls (non-load bearing walls which have a gap to prevent load transfer from the slab above.)
These items have been transferred to this ISAP due to the similarity in the inspections required.
The decision was made to expand the scope of the Action Plan to include all seismi: separation gaps. This decision was made based on findings from some of the initial inspectirsns that confirmed the presence of debris between buildings
,'s e e Section 5.3).
Added to the scope of the Action Plan were the gaps between adjacent base mats; and, gaps between base mats and adjacent walls. Although the design drawings permit the presence of foam in the base mat gaps, concrete seepage at foam joints was observed in single and double wall cases, I
thereby making < confirmatory inspection of all, base mat gaps necessary. However, to date, two instances have been identified as being inaccessible. The Project developed justifications to exclude these areas from the corrective action program. These justifications were reviewed by the third-party (see Section 5.6).
Inspection requirements were added in Revision 5 of QI-QP-11.0-3 to address the TRT request for an as-built inspection of seismic gaps.
These additions were included as a separate section within the procedure. As part of this revision, new inspection report forms were developed for as-built inspections of the gaps which required detailed docunentation. The procedure was modified in a fashion that anticipated some degree of debris removal by providing inctructions for documenting the initial condition as well as the final (after removal of debris) condition.
Revision 5 of procedure QI-QP-11.0-3 also included provisions designed to preclude intrusion of debris ir.co gaps. These provisions, which were retained in all subsequent revisions, require continuous QC witness whenever gaps are opened by removal of permanent seals or flashing.
If the activity extends over a long period of time, installation of temporary O
barriers is required when work is not actively conducted and when there is no QC witness. Upon completion of the activity and prior to reinstallation of the permanent seals and u e.
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1 Page 15 of.56 RESULTS REPORT ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd) flashing, a final QC inspection is required. These provisions apply to all activities conducted by the Construction organization. Upon transference of responsibility to the Operations organization, the seismic gaps defined in this ISAP will be controlled by an Operations procedure. A third-party review of the Operations procedure will be conducted and documented as part of the VI.a ISAP (the seismic gaps will be grouped with other " Critical Space" items identified as part of the VI.a Action Plan task related to debris in critical spaces and addressed through one, or a cohesive set of, Operations procedures - see Section'7.0).
Beginning with Revision 6, procedure QI-QP-11.0-3 incorporated new boundaries for inspection as well as additional instructions / clarifications for how the inspections were to be performed. Nearly all of the initial as-built inspections performed under this ISAP were conducted using Revision 6 of the procedure. Revision 7 added the Containment / Internal O'
structure interface to the list of boundaries to be inspected.
Revision 8 added considerations for inspection of separation gaps at the top of secondary walls and base mats. Each revision (beginning with Revision 5) was reviewed by the third-party (Reference 9.3) with concurrence given in matters regarding.this issue (i.e., inspection scope, methodology and maintenance requirements).
It should be emphasized that each revision was made to add a seismic gap type (e.g.,
Containment / Internal structure) to the scope of the procedure along with-inspection requirements unique to the new areas.
5.2 Initial As-Built Seismic Gap Inspections Following the issuance of Revision 5 of QI-QP-11.0-3, the Project began developing tools and techniques for conducting the gap inspections. An inspection approach was adopted that included the use of a video carera with voice recording, special lighting to facilitate fdeo taping, and probes of known dimensions.
A third-party overview of the initial inspections was conducted by SwRI (Reference 9.4).
Implementation of the inspection procedure (QI-QP-11.0-3) and the overall documentation process was included as part of the overview.
The scope and methodology of this overview is defined in the O
SwRI surveillance procedure (Reference 9.2).
This procedure applied to the initial as-built inspection overview as well as the final as-built effort (see Section 5.4).
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1 Page 16 of 56 RESULTS REPORT ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd) 5.3 Evaluation of Initial As-Built Inspection Findings and Ensuing Corrective Actions The initial inspections performed under this ISAP confirmed the existence of debris in many areas of the seismic gaps (Discrepancy / Issue Report (DIR) E-1052*].
Figures 2 and 3 present an example (for the containment #1 gap) that shows the approximate distribution of the debris found during the e
inspection process. The original scope of gap inspections included single wall and double wall gaps. After a number of initial inspections, it became apparent that there was a significant amount of debris in these areas. Therefore, a decision was made to expand the inspection scope to include all seismic gaps so that the effort would include base mats, the' containment / internal structure interface and the tops of secondary walls. Accordingly, the overview scope by third-party was expanded to include these areas.
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gj The -types of debris encountered included elastic joint filler material, Bisco fire sealant and damming material, concrete, wood scraps,.rebar tailings, and dirt. Pockets of various types of debris were sparsely located throughout the full height of double-walled gaps, with a higher concentration in the lower regions.
In the case of single wall, base mat, and secondary wall gaps, the " debris" primarily consisted of elastic foam left in place after pouring and concrete fragments.
In viewing the video tapes made for double wall gaps as part of'the inspections, many pockets of debris appeared to be a mixture of the various types listed above.
In some cases, two adjacent walls were found to be joined through a concrete " bridge" across the gap. Occurrences of this type were found for both single and double-walled gaps.
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The Discrepancy / Issue Resolution Report (DIR) is a form used to track the status, classification and resolution of all open issues and of all discrepancies identified during the implementation of this Action Plan as well as the Design Adequacy Program (DAP).
DIRs written in the course of implementing this Action Plan are identified in the related text of this report. All DIRs associated with this issue are summarized in Section 5.9 and tabulated in Table 3.
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RESULTS REPORT ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd)
Also observed in the inspections were seal materials (e.g.,
foam, fire sealant) that were intended by design. Although these materials are specified in the design, no calculations could be identified that demonstrate that the existence of these materials does not result in a significant increase in seismic response characteristics of the Category I structures, components and piping when compared with the results of the~
original analyses (DIR D-0166). Accordingly, the Project has prepared calculations in this regard for both building-to-building and secondary wall gaps. These calculations have been reviewed by third-party (see Section 5.6).
The initial as-built inspections also revealed that in some locations the seismic gap was less than specified by the original design drawings (DIR D-0004). The gap widths I
specified on these drawings indicate a single dimension for each building-to-building interface which exceeds the largest l
displacement calculated anywhere along the interface. Thus, the design basis building displacements calculated for the
' limiting load combination are less than or equal to the dimension specified on the drawings issued for construction.
To evaluate the significance of the areas where the as-built gap was less than specified on the drawings, Gibbs & Hill prepared calculations which provide the design basis building-to-building displacements for each seismic gap as a function af elevation. Also, calculations were prepared to establish displacements / gap requirements for the Containment / Internal Structure interface as well as for the tops of secondary walls (see Section 5.6).
These calculations were used to identify all areas where it was necessary to increase the width of the seismic gap to ensure that the FSAR statements regarding structural independence during abnormal conditions are satisfied.
Before the completion of the initial inspections for single and double wall gaps, an evaluation of the findings caused the Project to move directly to a corrective actions phase. These corrective actions began with debris removal from single wall gaps. After the minimum required gap calculations were completed and reviewed, the Project commenced work on single wall gaps with less-than-design separation width.
" Initial" inspections continued to be performed but were for the purpose O
of assisting Engineering in defining the appropriate corrective action.
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l RESULTS REPORT
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ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd)
Protopower-Bisco was contracted to effect debris removal from double wall gaps. The initial phase of their effort focused on developing the tools and techniques to dislodge and remove the various types of debris from the gap. The current scope of this effort now includes base mat and secondary wall gaps.
It is the Project's intent.that all foreign material be removed from the gaps.
If there are areas where removal is not possible or practical, a technical justification and/or analysis will be developed to demonstrate that seismic separation is not compromised.
In this event, a review of this work will be conducted by third-party and summarized in a supplement to this report. These third-party activities will be conducted in accordance with Appendix H of the CPRT Program Plan.
Another aspect of the corrective actions undertaken as a result of initial inspection findings involves adjustments to concrete walls in order to provide the minimum required gap width. The inspections identified some locations where the existing gap condition required widening.. Figures 4 and 5 present an example (for the containment #1 gap) that shows the locations where gap widening was required.
In order to provide adequate gap, some areas may require concrete to be
" shaved" from the surface to allow building movements predicted by the calculations. Although the amount of concrete removed is very small relative to thickness of the wall, the third-party will review the Project's assessment of significance of these removal activities as they relate to l
design requirements such as structural integrity and rebar coverage (see Section 5.6).
In the course of performing the inspections, three out-of-scope findings were made. These findings and resolutions are discussed in Section 5.10.
5.4 Final As-Built Seismic Cap Inspections Corrective actions are completed for the containment / internal structure interface (excluding internal base mats and certain areas under construction in Unit 2) and partially completed for the double wall, single wall, and base mat areas (i.e.,
debris removal and gap width adjustments).
As part of these corrective actions, all installed seals have been or will be O4 removed, the gaps examined and corrective actions undertaken as needed.
Final QC inspections (per QI-QP-11.0-3) have been A
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1 Paga 19 of.56 RESULTS REPORT ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd) completed for areas as corrective measures have been implemented. Following satisfactory results from QC inspection, all seals will be reinstalled per design requirements. SwRI conducted an overview (Reference 9.5) of the earliest final as-built inspections and documentation of the as-built condition which involved the Containment / Internal structure interface. This overview determined that the corrective actions are effective in insuring that the design requirements are met.
Additionally, the inspection procedure (QI-QP-11.0-3), and the effectiveness of QC personnel in implementing the procedure, were determined to be acceptable.
5.5 Documentation Review In an effort to determine root cause and assess the
~
possibility of generic implications stemming from this issue, a documentation review was performed (References 9.6 and 9.7).
Of interest were correspondence between the engineering and O
construction organizations, the procedures used to monitor concrete pours, Inspection Reports, and NCRs related to seismic gap debris and width.
5.5.1 Correspondence Review The initial question regarding placement of elastic foam material arose in 1976 when ths field requested permission to install and leave in place the foam below waterstops (Request for Information or Clarification number C-029, January 29, 1976). This request was made because the design called for an air gap but the placement of the waterstop made foam removal difficult.
TUGC0 Engineering responded in FPAR 110, (February 13, 1976) by 7tating that the foam could be left in place "both below and above waterstops". A Gibbs & Hill telex (GTT-1543) was issued in September of 1977 which stated that construction was proceeding on an erroneous interpretation of the FPAR response. Gibbs & Hill explained that the FPAR allowed leaving in place the fcam above and below the waterstop but only up to the grade line. Although this latter point was not explicitly stated in the FPAR reply, the structural drawing (2323-S-0786) revised at that time clearly shows foam between base mats below grade and an air gap O
above grade. The Project issued a memo (TUS-5019, November 2, 1977) which defined the extent to which elastic foam material was to be removed.
This memo A
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1 Paga 20 of 56 RESULTS REPORT ISAP II.c (Cont'd) 5 '. 0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd)
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allowed foam to remain in place for specific areas already constructed, required a one inch air gap for other specific areas already constructed and required a I
two inch air gap for future construction. No technical justification was provided in the memo for this design j
change and no engineering evaluations have been identified that support these decisions (DIR D-0166, i
E.eference 9.8 and 9.9).
[ Subsequently, new design calculations performed under this Action Plan (see Section 5.6) did justify the design change implied by this meno.]
2 Beginning in November of 1977, discussions between TUGCO, Brown & Root, and Gibbs & Hill commenced regarding the need to protect the seismic gaps from the intrusion of debris. The result of these communications was a mutual agreement that a strip of elastic foam filler material could be installed at the construction joint such that, following the pour of the i.
next portion of the wall, debris that collected at the foam strip could be readily removed. This approach included the restriction that the foam atrip could not remain and eventually was to be removed. No evidence exists that this methodology for gap protection was ever proceduralized. The results of the gap inspections conducted under this Action Plan confirm the use of foam strips as a means of protection by having identified a few strips that had not been removed.
Halliburton was contracted to remove foam in late 1977.
Following Halliburton's efforts, a Gibbs & Hill meno was issued (GHF-2390, January 30, 1978) to Construction Management stating that a Gibbs & Hill Field Engineer and a TUSI Civil Engineer had inspected the areas identified for repair in TUS-5019, and found these areas acceptable. No information exists as to the rigor employed in these inspections. However, a Brown
& Root memo was issued two weeks later (IM-12939, February 19, 1978) to Construction Management from the Site Quality Control Manager, stating that removal efforts were not complete based on observations made by QC inspectors and that further removal and/or O
engineering evaluation was required. Also, this memo specifically requested a written response defining actions and schedule. No documentation was located
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RESULTS REPORT
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ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd) which indicated that Construction Management responded to this memo or that the Site Quality Control Manager followed up on his memo.
The third-party interviewed the individual responsible for initiating the memo.
This individual stated that the TUGC0 QC Supervisor informed him that, since TUGC0 was assuming QC responsibility (which occurred officially in July 1978), he (the B&R QC Manager) did not need to pursue the seismic gap issue (Reference 9.10).
Although TUGC0 assumed QC responsibility, there is no evidence that TUGC0 QC documented the concern on a QC record (NCR or Corrective Action Report) or that there was any follow-up to the identified concern (DIR D-2141).
No record of further Halliburton activity or engineering evaluation addressing the identified condition has been located.
l' The conflicting reports (i.e., the Gibbs & Hill and
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B&R memos) and the absence of a full set of inspection reports related to the B&R QC inspection (see Section 5.5.3) raise questions about the quality and effectiveness of implementation of the task assigned to Halliburton. Although the B&R memo (IM-12939) clearly defines a quality concern, appropriate' action was apparently not taken. Aside from the memo, no open inspection reports or NCRs existed to document the unsatisfactory condition (i.e., presence of debris and less-than-design gap width) that would require a closure.
/
5.5.2 Procedure Review Procedures that relate to the construction and inspection of concrete walls were identified and reviewed by the third-party (Reference 9.11).
The following summarizes this review.
Concrete placement control was initially the responsibility of Brown & Root (B&R).
Brown & Root QC Procedure CP-QCP-2.4, " Concrete Inspection and Testing", was issued in July 1975, and was in effect until July 1978.
This procedure addressed concrete
(N qualification test adequacy, documentation
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requirements, as well as placement inspections prior to, during, and after pours.
In all revisions of this
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. 1 Page 22 of 56 RESULTS REPORT 4 --
ISAP II.c (Cont'd) 5.0 ' IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd) procedure, there was no explicit requirement to check the as-built seismic gap width against the design documents. Also, the procedure did not require a check of whether debris had fallen into the air space in the process of pouring or after a pour had been completed.
As part of the late 1977 Halliburton effort to' remove foam inadvertently left in place during pours above i
grade, Brown & Root QC developed a temporary procedure to verify the effectiveness of this effort.
The procedure, CP-QCI-2.4-9
" Inspection of Elastic Joint Filler Material Removal", required a one-time inspection of the areas identified in TUSI memo TUS-5019 to verify that foam had been removed and that the minimum air gap had been maintained as required by design drawings.
In July 1978, CP-QCP-2.4 was replaced by TUGC0 Procedure QI-QP-11.0-3, " Concrete Placement i
Inspection". The scope of this procedure addressed pre-pour planning verification and inspection prior to 4
and during the concrete placement. Present in i
Revision 0 of this procedure was the requirement for QC inspectors to verify that dimensions of the seismic air gap complied with design drawings and that the gap was protected from the intrusion of foreign objects prior' I
to placement.
It is not apparent from the text of the procedure whether the check for adequate protection was related to the plan to use foam strips at construction joints to capture debris (see Section 5.5.1).
Discussions with QC personnel who were onsite during the late 1977 to mid-1978 timeframe indicated that the use of foam strips as a means of protection was not communicated to QC personnel as an item which'should be specifically inspected prior to a pour (Reference 9.12 and 9.13).
There was no requirement to verify that foreign material had not entered the gap during or following the pour or that the dimensions of the gap following the pour still eszplied wi L the design drawings.
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RESULTS REPORT
.ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd)
The only procedure identified that contained post-pour inspection requirements was QI-QP-11.0-5, " Inspection of Concrete Repair". Early revisions of this procedure did not contain any provisions for gap inspections-(up to and including Revision 4).
Gap inspection requirements (post-pour) have been added in the Revision 5 (issued 5/28/86) version of this procedure.
It should be noted that by the time QI-QP-11.0-3 was instituted, many of the major concrete pours had been completed (mid 1978). This procedure (now called
" Concrete or Mortar Placement Inspection") is still in effect and has been modified donsiderably so as to prevent debris and gap width problems.
,i 5.5.3 Inspection Records Review The presence of foam in the seismic gap was initially identified without the use of an inspection report.
r.
The condition was discovered and disposed of through 4
Engineering correspondence between Gibbs'& Hill and the Project (see Section 5.5.1).
During the foam removal operation performed by Halliburton in 1977-78, a Brown & Root QC procedure was written to verify removal efforts. This procedure, CP-QCI-2.4-9, " Inspection of Elastic Joint Filler Material Removal", provided instructions for QC personnel to verify foam removal and minimum air gap dimensions. Only two checklists i-that relate to this procedure have been located (DIR D-2143). These two checklists (Reference 9.6) address a small portion of the overall scope defined in
[.
TUSI meno TUS-5019. One checklist mentions the use of 4
a tape measure to perform gap measurement whereas the inspection procedure specifies the use of gage blocks as the appropriate technique (DIR D-2144). No indication of inadequacy is present in the reports; yet, Brown & Root meno IM-12939 (see Section 5.5.1) indicated that the removal effort was incomplete for a specific area inspected by B&R QC personnel (the areas covered by the two inspection reports mentioned above
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1 Paga 24 of 56
'g-').
RESULTS REPORT U
ISAP II.c
- (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd) are different from the area discussed in IM-12939).
It is not clear whether the inspections referred to in the Brown & Root meno were part of the same effort conducted under CP-QCI-2.4-9.
It should be noted that these inspections and corrective actions (TUSI Memo TUS-5019, November 2, 1977) could only address those areas completed at that time. Hence, their scope did not include all the air gaps that are presently of concern.
In late 1978, QC inspections were conducted for gap cleanliness and minimum width. The new Project procedure (QI-QP-11.0-3) was utilized as a guide for the inspection although it contained no explicit instructions for a post-pour inspection. The scope of these inspections was greater than those performed under CP-QCI-2.4-9 since concrete pouring had continued.
Five inspection reports were written that
()
identified various types of construction debris in the seismic gap. One report identified a gap width less than the specified design value (1 3/4" as' opposed to 2").
As was the practice, these reports were brought to the attention of construction management for scheduling craft support in correcting the condition.
Based on third-party observation of the gap' condition during implementation of this Action Plan, it appears i
that an attempt had been made by Construction to remove the material from the gaps, but this effort was not completely successful (star drill holes were observed by the third-party in the concrete between the Fuel and Auxiliary Buildings). Subsequently, in 1983, these open inspection reports were grouped together, attached to NCR C-83-01067, and routed to TUGC0 Engineering for disposition (see Section 5.5.4).
There are no procedural requirements for resolution of open inspection reports in a reasonable timeframe (Reference 9.14) (DIR D-2145). No other irs involving seismic gap i
width or debris have been identified.
l 5.5.4 NCR Review The NCR referred to by the TRT in Reference 9.1 (C-83-01067) was written to identify two unsatisfactory O
situations recorded on inspection reports. The first had to do with the presence of debris in a few areas between buildings. The second involved the measured gap width being less than design requirements. The i
w
-e,--,
r er,-.
,---,o w
e----
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1 Pags 25 of 56 RESULTS REPORT ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd) related inspection reports date back to late 1978.
However, the NCR itself was not written and closed until 1983. The NCR has since been re-opened (as Revision 1) to address TRT concerns.
The disposition of the original NCR (Revision 0) justified accepting the debris in the gap, and the areas of less-than-design gap width, on the basis that the seismic displacements for the area in question were less than the pressurization displacements observed during the containment Structural Integrity Test (SIT, Reference 9.15)*.
Thus, the SIT was considered as a proof test which demonstrated that the conditions described in NCR C-83-01067 were acceptable. TUGC0 I
Licensing reviewed the disposition of this NCR and determined that it would satisfy FSAR commitments (Reference 9.7).
The review conducted by Licensing was not for technical adequacy, but only verified that the
~
j disposition to the NCR addressed the separation
/
requirements stated in the FSAR.
The disposition of this NCR has been reviewed by the third-party and found to be technically incorrect in that the limiting load case from FSAR Section 3.8.1.3.2 includes the factored sum of seismic, pressure, and temperature effects for the Containment (DIR D-0004).
A more complete treatment of the discrepancy related to this NCR is presented in Section 5.7.
5.6 Review of Engineering Requirements for Seismic Gaps l
The TRT had requested that analyses be prepared to demonstrate that foam and any other debris identified in the seismic gap does not result in any significant increase in seismic response. This request presumed that foreign material would l
be left in place. However, the Project has decided to remove all material from the seismic gaps, such that only seal material required by design was to remain in place.
For this reason, calculations considering the effect of debris found during the gap inspections were not required.
The NCR specifically cites the Structural Acceptance Test (SAT) as
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the source for pressurization data.
The report (Reference 9.15) refers to this as the Structural Integrity Test (SIT).
Both refer to the same test.
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1 Page 26 of 56 g ~3 RESULTS REPORT V
ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd)
The Project did prepare calculations to support various aspects of activities related to the implementation of this Action Plan. Gibbs & Hill completed calculations that determined the relative building displacements to be used as inspection criteria for gap width verification / correction.
The building-to-building relative displacements were prepared utilizing the most conservative load case combination equations out of the FSAR and included adjustment for thermal expansion effects. Displacement calculations were done for each of the buildings in addition to the Containment Internal Structure gap and secondary wall gaps. The third-party has reviewed these calculations and concurs that they correctly reflect the FSAR commitment for seismic separation.
Although there was no need to assess the effect on building response due to debris identified in the seismic gaps (since it was to be removed), the Project did this assessment to account for the effect of seal material in the gap by design.
(~.')
Two types of calculations were prepared, the firet demonstrating that the presence of seal material between buildings did not have a significant impact on building response. The second type of calculations demonstrated that seal mat.erial at the tops of secondary walls did not have a significant effect on the supporting slabs. The third-party also reviewed these Gibbs & Hill calculations and found them
)
to be adequate in demonstrating that the presence of these materials does not have a significant effect on the seismic response of the buildings.
l l
In order to completely verify the adequacy of the gap condition, the Project has committed to remove all seal material in seismic gaps where practical.
After removal and verification of the absence of debris and adequate gap width, the seal material will be reinstalled. The Project is preparing calculations to demonstrate the adequacy of the seal
(
design in accounting for relative motion. Vendor restrictions on the degree to which the seal material can be compressed are being considered on a case-by-case basis to ensure the adequacy of seal behavior as well as the validity of seal load transfer assumptions used in the respense calculations mentioned above.
The third-party will overview the completion of these calculations, as described below.
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1 Pags-27 of 56 t
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RESULTS REPORT ISAP II.c (Cont'd) i 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd) 4 The Project is also preparing calculations.to support the decision to leave certain commodities (designed items) in the gap.
There are few instances of this type and usually involve a run of conduit. Gibbs & Hill has completed one calculation which demonstrates that an in-gap commodity (i.e., conduit containing non-safety grade lightning grounding cable) is not adversely.affected by relative building movement, ac well as showing that the presence 'of the commodity does not adversely affect the otructures forming the gap (i.e., no significant local damage and no significant effect with respect to building response). The third-party will overview this calculation and other calculations of this type as part of the l
overview activities discussed below.
It was anticipated at the onset of the gap inspection effort
- that some areas may not be accessible. To date, only two areas have proven to be such. The Project has defined the
,j, areas and developed a technical justification for excluding 1 -
the areas from the program (References 9.16 and 9.17).
Both areas are located at base mats with configurations that prohibit examination unless portions of walls and floors are removed.
Instead, the Project has excluded these areas from the corrective action program on the basis that the relative displacements at these locations are essentially non-existent (t'he base mat locations in question are either in contact with the underlying rock or show a common foundation). The third-party has reviewed the Project evaluation and has agreed with the Projects' conclusion to exclude these areas from the
~
l corrective action program (References 9.13 and 9.19).
Five DIRs have been written in the course of ' reviewing Gibbs &
Hill calculations reisted to the gap.
One of these, DIR i
(
D-1346, has been found to be unsubstantiated. Another, DIR D-1347, identified a discrepancy related to slab design and has been transferred to DAP for consideration. The other three DIRs (D-0258, D-0259, D-0260) have been closed as observations, the identified discrepancies having been resolved through the issuance of new or revised Gibbs & Hill calculations.
l The Project made the decision in October 1986, to replace l
l Gibbs & Hill as the engineering organization responsible for all Civil / Structural design work with Stone & Webster O
Engineering Corporation (SWEC). SWEC is conducting a complete verification of the design work in the Civil / Structural area under the SWEC Corrective Action Program, which includes all T
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1 Pags 28 of 56 L
RESULTS REPORT ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd) calculations performed by Gibbs & Hill related to separation gaps. The third-party reviews of the Gibbs & Hill gap calculations completed to date have each concluded that the calculations examined were adequate. However, these reviews were limited in scope to the gap calculations themselves, i.e.,
the results of previous Gibbs & Hill work used as input to the gap calculations (e.g., seismic building models) were assumed to be correct. Because the verification effort has the potential to alter results used as. input to the gap calculations, and because DAP will be conducting an overview of the SWEC verification program, a final determination of the adequacy of separation gap-related engineering requirements will be reached by DAP.
In particular, DAP will review the calculations.related to the seismic gap (including those already reviewed as part of work done for this Action Plan should they be retained by SWEC).-
5.7 Evaluation of NCR C-83-01067
'O As described in Section 5.5.4, the subject NCR accepted i
"as-is" both the presence of debris in the seismic gap and the less-than-design gap width, based on a technical analysis which is inconsistent with the applicable FSAR load case combination.
The NCR analysis is based on a comparison between predicted combined seismic displacements for the containment and adjacent buildings, and the observed displacements recorded during the Structural Integrity Test (SIT, Reference 9.15) performed for Unit 1.
The SIT pressurized the containment to 115% of the design value (design is 50 psi) to establish the adequacy of the structure in withstanding loss of coolant accident effects. The NCR i
concludes that the expected seismic displacements are less than the observed radial growth experienced during the SIT l
and, therefore, "... remaining materials in the gaps are acceptable 'as is' without further rework."
Section 3.8.1.3.2 of the FSAR defines a load case which includes the factored sum of seismic response as well as pressure and temperature effects. This load case would produce the governing situation in terms of relative building displacements. The NCR disposition did not. address this load case but, instead, considered building growth due to pressurization alone.
9
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(U RESULTS REPORT ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd)
The conclusion regarding the inadequacy of the NCR disposition led to an investigation of other NCRs signed by the engineer responsible for the subject NCR. All NCRs in a six month timeframe (three months on either side of the subject case, dated April 17, 1983) were examined by the Project to identify those with this individual's signature as the engineering representative approving the dispositien. The third-party reviewed each of these NCRs to identify those where a technical justification for altering the design was provided (according to ANSI N45.2, Criterion 16, dispositions where "use-as-is" or " repair" are proposed require a technical justification for allowing an alteration of the design). The resulting collection of twenty-two NCRs was then reviewed for technical adequacy by the third-party. This review identified no other instances where an incorrect technical analysis was provided within an NCR disposition (Reference 9.20).
This investigation of NCRs over a six monti period supports the 7-~
conclusion that there was no adverse trend associated with the (j
individual who signed the subject NCR.
5.8 FSAR Update Assessment The Project conducted a review to determine the naed to update the FSAR based on inspection findings. The results of the Project review revealed that a revision to Section 3.8.5.1.3 was required to reflect the as-built condition more accurately. The proposed change has been submitted for incorporation into the next update of the FSAR (Reference 9.21).
The third-party has reviewed the Project's FSAR impact assessment and concurs with the conclusions drawn (Reference 9.22).
Any subsequent action to this particular change request or any new change requests will be reviewed by the third-party (see Section 7.0).
5.9 Summary of DIRs Seventeen DIRs were written during the course of implementing the II.c Action Plan.
They are summarized in Table 3.
Six of these DIRs (D-0166, D-0258, D-0259, D-0260, E-1220, D-2133) have been closed with a classification of " observation",
i.e.,
the identified discrepancy has been determined not to be a l
violation of a design criterion, commitment or specification.
Each of the six observations has been completely resolved such
()
that no further action is required.
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RESULTS REPORT
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ISAP II.c l
(Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF.RESULTS (Cont'd)
Seven of the seventeen DIRs have been transferred from this Action Plan.
Five of these seven DIRs (D-2141, D-2142, D-2143,~D-2144, D-2145) have been transferred to the QA/QC Review Team because the discrepancies relate to QC issues (Reference 9.23).
Of the remaining two DIR D-2132 has been transferred to ISAP II.d (" Seismic Design of Control Room Ceiling Elements") and DIR D-1347 has been transferred to DSAP VIII (" Civil / Structural Discipline Specific Action Plan").
One of the remaining four DIRs (DIR D-1346) has been closed as
" unsubstantiated",
i.e.,
the originally-identified discrepancy has been found to have no substance after additional information had been obtained.
The remaining three DIRs (D-0004, E-0987, E-1052) have been closed and assigned the category " unclassified deviation",
i.e., a violation of a design criterion, commitment, or specification had occurred but it had been determined that it was more practical to proceed directly to analyzing root cause and generic s
}
implications'and specifying of corrective actions. No safety significance evaluation is required in this situation (see Section 5.11).
Root cause and generic implications relating to these three discrepancies are addressed in Section 5.12.
The corrective actions associated with these discrepancies have been defined in Section 5.3.
All of the above DIRs, except for those transferred to the QA/QC Review Team and the one determined to be unsubstantiated, remain a part of the DAP Tracking System and will be included in the DAP trending evaluations.
5.10 Out-of-Scope Observations 5.10.1 Fuel Building Wall Damage In preparing an area for removal of debris and widening of the air gap, craft personnel discovered that a piece of the corner of the Fuel Building east wall adjacent to the Unit I containment between elevations 860 and 870 was broken. The broken piece (approximately 1.5 ft. long and about 1 foot in width and depth) included a well-consolidated concrete bridge in the seismic air gap between the Unit I containment and the end of the fuel building wall (see Figure 6).
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1 Page 31 of 56 rg RESULTS REPORT ISAP II.c I
(Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd) 1 i
The procedure used for concrete repairs (CCP-12) required that the area to be repaired be chipped to sound concrete and, if reinforcement bars are exposed, that the concrete be removed around the exposed bars to a distance of 1-inch on all sides. While preparing this area for repair, cracks running parall' l to the a
outer row of reinforcement bars were encountered.
These observations were documented by the Project in subsequent revisions to NCR C-85-101778S (Revision 0 was written following discovery of the dislodged block of concrete) and diceussed with the third-party.
In addition, in chipping out concrete to effect repair, a
- 4 cap bar (face-forming rebar) was observed to be i
misplaced.
This was documented and resolved on the above NCR. Further consideration of this aspect (i.e.,
misplaced rebar) will be addressed within ISAP II.a.
" Reinforcing Steel in the Reactor Cavity".
(h Inspection of the repair area and subsequent evaluations (part of NCR disposition) led to the conclusions that the probable cause of the cracking and the breaking loose of a piece of the corner of the wall was a mechanical interaction between the containment wall and the end of the Fuel Building wall in the area of the concrete bridge during the Structural Integrity Test (SIT).
In this location, the radial displacement of the containment wall during the SIT was measured to be of the order of 3/4" (Reference 9.15).
The corrective action plan for this NCR included the following:
Repair of the cracked corner of the Fuel
-Building wall per Project procedures.
Examination of all other areas where concrete bridges existed in the gaps between the Unit I containment and adjacent buildings (because all debris will be removed prior to the Unit 2 SIT, it will not be necessary to examine areas surrounding the Unit 2 containment for mechanical interaction).
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RESULTS REPORT i
ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS.(Cont'd)
The examination identified above has been conducted by the Project with assistance from Mr. Richard Orr, a i
recognized expert in evaluating concrete for structural' j'
integrity, who was employed by the Profect as a consultant. The investigation showed that no other
}
instances of wall breakage had occurred as a result of
.the SIT.
Three areas of contact with the Safeguards Building were identified where, because of their 4'
-locations and the sizes of their areas, it would be reasonable to expect potentially large contact forces.
Under the direction of Mr. Orr, an analysis was performed to determine the magnitude of the maximum concentrated force between the Safeguards Building and the Unit 1 Containment Building which may have developed during the SIT, and the effect of this force on the two buildings. The results of this analysis, as well as a. summary of the investigation conducted to identify local damage, have been documented in Reference 9.24.
The third-party reviewed the Projects' investigation and analysis results and concluded that the question of potential damage due to building-to-building contact during the SIT has been satisfactorily resolved (Reference 9.25).
5.10.2 Concrete Voida In the process of chipring an access hole through a concrete wall to effect debris removal in a double wall gap, a concrete void was discovered. The situation was documented in NCR C-86-101455. The void was located at a construction joint (the line of separation between sequentially poured concrete lifts) in the 8S wall l'
(north wall) of the Safeguards building at elevation 797'.
This void is being considered by the Project in an investigation program for concrete voids described in Reference 9.26.
The third-party will overview the i
Project investigation as part of the DAP overview effort (see Section 7.0).
l l
5.10.3 Commodities Bridging Seismic Gaps The gap inspections have identified instances where l
plant equipment span the seismic gap (DIR D-2132).
One
()
example of this situation involves rigid conduit that is attached to a secondary wall and runs vertically to an attachment point on the ceiling. The conduit does l
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Paga 33 of 56 U.
RESULTS REPORT p
ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd) not intrude into the seismic gap at the top of the secondary wall, but does rigidly bridge the wall and ceiling which are expected to respond differently during a seismic event. This situation in itself does not violate any existing design criteria. The subject of relative building motion for plant equipment near, or bridging, seismic gaps has been included in the scope of ISAP II d, " Seismic Design of Control Room Ceiling Elements", as part of the task for Damage Study Verification (see Section 7.0).
5.11 Safety Significance Assessment The presence of debris in the gap, the existence of less-than-design gap width, and the error associated with the disposition of NCR C-83-01067 have been categorized'as
" unclassified deviations". No safety significance assessment was performed because a determination of safety significance O
in each case would require extensive analyses to establish whether the direct result would have been the loss of functionality of a safety-related structure, system, or component, if the discrepancy went undetected. Consistent with the Project Plan, root cause and generic implication assessments were performed and are provided in the following section.
i 5.12 Root Cause and Generic Implication Assessments t
5.12.1 Debris in Seismic Gap The circumstances that led to debris in the seismic gap were examined from two perspectives:
(1) why was.
debris allowed to enter the gap and (2) why was the l
debris not detected and removed prior to the TRT l
investigation? This section summarizes the potential causes that were evaluated 'and the conclusions reached.
Initially, a misunderstanding between the Construction and Engineering organizations allowed foam forming r
l material to be left in place above the base mats following concrete pours. Although 1t was later nade clear that the design required open gaps (i.e., foam removed following a pour), the 1977 corrective actions O
to remove foam do not appear to have been fully effective based on inspection results from 1978 as well as the results of the inspections performed under this action plan. The lack of effectiveness of the 1977
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1 Pegs 34 of 56
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RESULTS REPORT U
ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION 0? RESULTS (Cont'd) corrective action to remove foam.is not by itself considered to represent a root cause of debris in the gap since significant quantities of other types of debris (i.e., dirt, concrete and construction scraps) entered the gap during subsequent pours, primarily because of the change in forming practice to a slip form method (since the gap was no longer filled with foam, other types of debris were no longer restrained from entering).
Yet, these actions give an indication of a lack of adequate attention by QC, Engineering, and Construction Management, to ensuring that the seismic gap was maintained in accordance with design requirements. All three organizations were aware of the inadequate gap condition, but a combined lack of action allowed the condition to go uncorrected.
It is possible that this apparent absence of concern regarding the seismic gap allowed subsequent incidents involving debris intrusion (e.g., concrete spillage,
()
construction scraps, etc.) to not only go uncorrected but unidentified.
The cause of construction scraps and dirt in the air gaps is clearly related to inadequate protection of these gaps during or after construction of the adjacent walls. The concrete found in the gaps is probably related to form leakage or spillage. No matter which forming technique is used (e.g., foam, slip-forming),
the potential exists for concrete intrusion or spillage and for other debris to enter the gap. Therefore, the forming technique by itself cannot be a cause of this problem because standard construction practices may be assumed to allow debris to enter the gap and to require remedial action. Pre-pour inspections by both craft supervision and QC for form tightness were called for by the first procedures used for concrete pours.
However, explicit instructions for protection of the gap were not included prior to mid-1978 (as stated in Sections 5.5.1 and 5.5.2, a methodology for gap protection was developed but was not proceduralized or communicated to QC for verification purposes). Until recently these checks for gap protection were limited to pre-pour inspections (QI-QP-11.0-5, " Inspection of Concrete Repair", was revised in May of 1986 to include these new requirements). While post-pour inspections were performed for concrete defects, no procedure has been identified chat required a post-pour check for gap cleanliness, protection of the gap from debris u
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RESULTS REPORT
'f ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd) 1 intrusion, or verification of the as-built gap width.
]
The lack of an effective construction procedure requirement to protect the gap and the lack of a QC procedure requirement to verify that the gaps were free of debris and protected (especially after a pour) are considered to be major causes of debris in the seismic air gaps.
The question of why debris were not detected and removed prior to the TRT investigation led to an examinction of the role of QC in this area. As discussed previcusly, QC procedures did not require a post-pour inspection to verify that the seismic air gaps were free of debris and protected from debris intrusion (DIR D-2142). Had these steps been included in the inspection procedures, it is likely that significant debris intrusion would have been prevented or detected.
The lack of timely processing of the inspection reports from the 1978 inspection (see Section 5.5.3) and the subsequent erroneous disposition of NCR C-83-1067,
~
while clearly a missed opportunity to correct the problem, are not considered to be the cause of the current conditions remaining undetected and uncorrected. This conclusion is based on the observations that debris was found in areas not covered
[
by the 1978 inspections and that without protection of the gaps debris could have entered after the 1978 inspections.
i l
Accordingly, the root cause for the presence of debris l
in the seismic gap is inadequate construction and QC procedures for the in'-process protection and post-pour l
inspection of the seismic gaps. The significance of i
these procedural inadequacies, in addition to the possible determination of a higher level root cause, will be considered by the QA/QC Review Team in their Collective Evaluation.
The implication of inadequate procedures for protection and inspection of seismic gaps is that it is unknown whether or not and the degree to which other critical O
air spaces required by design have been maintained as such. This possibility has been addressed within the Critical Spaces Program established by ISAP VI.a.
The purpose of that program is to identify all spaces in which the existence of debris, equipment, or structures may adversely affect a safety-related system, structure, or component.
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1 Page 36 of 56 RESULTS REPORT ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF~ ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd) 5.12.2 Less-Than-Design-Gap Width 4
The circumstances that led to less-than-design gap width were also examined from two perspectives, namely:
what caused the condition and why was it not detected
~
and corrected earlier?
The two forming techniques (foam and slip form) used in constructing the structures related to the seismic gaps have been employed in constructing similar structures in other power plants, and, as is ev$ dent at CPSES, can provide suitable results. However, both techniques inherently produce small variations in the plane of the concrete surface. These variations may result from such causes as variation in forming material thickness and compression (in the case of foam) or form positioning and bulge (in the case of slip forms).
i
. Variations in concrete forming are accounted for in American Concrete Institute (ACI) Standard 301-72 which provides recommended tolerances for concrete construction.
Construction at CPSES was and still is controlled by j_
structural drawings which specify the design gap width and Gibbs & Hill specification 2323-SS-9 which references ACI 301-72 as the guideline for construction tolerances. Lacking'any instruction for alternative application of those tolerances, it is implicit that they would be applied as a positive and negative variance relative to the design dimension [e.g., 2" (tolerance per ACI 301-72)]. Therefore, less than design gap dimension [e.g., 2" - (tolerance per ACI 301-72)] would be considered to be within tolerance It appears that the construction organization made an effort to construct the gap so that the design gap was achieved; nevertheless, there were some areas where less than design gap width resulted. Even'if a rigorous QC inspections program had been employed to verify the seismic gap dimension, it is inevitable that some degree of less than design gap dimension would have been accepted as satisfactory (i.e., within tolerance).
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1 Pags 37 of 56 RESULTS REPORT ISAP II.c (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION OF RESULTS (Cont'd)
It is evident that the intention of the design in satisfying the FSAR commitment was that the seismic gaps are a minimum value. There is no evidence in the
' original design that a' tolerance value was incorporated to allow for the ACI tolerances. Accordingly, to provide an acceptable result, any tolerances could only be of a positive sign ie.g., 2" - 0" + (tolerance per
- ACI 301-72)].
In this case, an error in application of tolerance is particularly important because of the small absolute value of the seismic gap dimension.
Thus, it is concluded that a cause of the less-than-design gap width condition is that the design did not correctly define how construction tolerances were to be included (DIR D-2133).
As discussed.in Section 5.12.1, QC procedures did not require a post-pour verification of the cleanliness,
)
protection, or the as-built dimensions of the air gaps.
/
While the 1978 inspection did identify one area of less than gap width, such inspections were not required by the QC program to be performed on a regular, comprehensive basis. Thus, it was concluded that the primary reason that the less than design gap width condition was not detected and corrected earlier was that regular pcst-pour inspections of the as-built gap width were not required by the QC program.
Accordingly, the direct cause is considered to be a combination of two factors:
(1) the design did not clearly define how construction tolerances affecting the gap width were to be included (this represents an interface problem between the design and construction organizatians) and (2) post-pour verification of the as-built gap width on a regular basis was not required by the QC program.
The implication of r..". adequately defining construction tolerances in the controlling design documents would, of course, extend to all seismic gaps. As part of the corrective actions under this Action Plan, all seismic gaps will be inspected (unless otherwise justified) and in instances where gap widths are found to be O
inadequate, corrected. The root cause regarding construction tolerances not being clearly defined within the design will be considered within DAP as part of its evaluation of potential adverse design trends, t
and within the QA/QC Review Team as a result of its hardware inspection effort.
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1 Page 38 of 56 RESULTS REPORT V
ISAP II c q.
j (Cont'd) 5.0 IMPLEMENTATION OF ACTION PLAN AND DISCUSSION.0F RESULTS (Cont'd)
The implications of the second direct cause, i.e.,
lack.
of post-pour verification (design conformance) on the part of the Project QC organization, are similar to those stated in Section 5.12.1.
5.12.3 Technically Incorrect Disposition of NCR C-83-1067 Inspection reports completed in late 1978 identified instances of less than design gap width and debris in the seismic gaps. These reports remained open until 1983 when, during the building turnover process, they were found to be unresolved. Construction attached these inspection reports to NCR C-83-1067 and sent them to Civil / Structural Engineering for disposition. As discussed in Section 5.7, the disposition provided by Engineering accepted as-is the identified non-conformances using an analysis that was technically incorrect.
The root cause related to this matter is a technical error on the part of the responsible engineer within the Civil / Structural Engineering group. An investigation of other NCRs approved by the same l
engineer in a six-month timeframe identified no other technically incorrect dispositions, thereby dispelling any generic concerns related to this individual. A i
more comprehensive investigation of the technical adequacy of NCR dispositions is being performed by the Project with a third-party overview being conducted by DAP.
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6.0 CONCLUSION
S Based on the third-party's investigations, all seismic gaps have l
been identified and have been or will be inspected, with two l
exceptions identified to date. For these two cases, acceptable justifications were developed that demonstrate seismic separation is maintained. The reinspections identified areas of significant debris accumulation and less-than-design gap width, thus confirming j
the TRT concern that the FSAR constitment for seismic separation had not been achieved. The Project is continuing to inspect all seismic air gaps.
In-process overview by the third-party has O
confirmed that the procedures used and their implementation are effective in identifying the areas requiring corrective action.
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'RESULTS REPORT ISAP II.c (Cont'd)
6.0 CONCLUSION
S (Cont'd)
The Project is in the process of removing debris, widening the gaps where necessary and performing a final verification that the gaps meet the FSAR commitment for seismic separation. The third-party has performed in-process overviews of the final inspection for those areas where the Project corrective action is complete. Based on these overviews, it is concluded that the procedures used and their implementation have been effective in assuring that the design gap width is achieved, that the gaps are free of debris and that they are protected from future debris intrusion.
Gibbs & Hill has prepared calculations to establish the design basis building displacements and to confirm that the (elastic foam) materials designed to be present in the seismic gaps (e.g.,
environmental and fire seals) do not invalidate the assumptions or dynamic models used to analyze the seismic response of the building. The third-party has reviewed these calculations and-concurs that they correctly reflect the FSAR commitment for seismic separation, and demonstrate that the presence of these materials do O
not have a significant effect on the seismic response of the -
buildings.
However, due to the verification effort being conducted by SWEC in the Civil / Structural design area and the potential for this verification effort to affect engineering results used as input to the Gibbs & Hill separation gap calculations, a final determination of adequacy for the engineering requirements related to the seismic gap will be made by DAP in their overview of the SWEC verification effort.
One of the M -of-Scope Observations made during the implementation of this Action Plan (Section 5.10.1) involved the discovery of damage to the Fuel Building wall. The concrete bridge between the Fuel Building and Containment Unit I walls transferred forces to the Fuel Building as a result of the radial expansion of the Containment structure during the Structural Integrity Test (SIT).
The affected area was repaired in accordance with procedure. The Project then conducted an investigation of other locations along the Containment Unit I wall where concrete bridging had been observed, to determine if the expansion of the Containment caused by the SIT gave rise to adverse structural effects. The results of the field survey and the analysis performed by the Project were reviewed by the third-party. It was concluded that the question of potential damage due to building-to-building contact during the SIT had been satisfactorily resolved.
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Paga 40 of 56 RESULTS REPORT ISAP II.c (Cont'd)
6.0 CONCLUSION
S (Cont'd)
The third-party has evaluated the root cause and generic implications of the three unclassified deviations identified by the investigations 'erformed under this action plan. Based on this p
evaluation, it was concluded that this action plan has fully addressed the generic implications relative to seismic separation gaps and that similar deficiencies, if they existed in othar areas, would be detected by the investigations being conducted under ISAPs II.a, II.d. VI.a and the DAP and Quality of Construction programs.
7.0 ONGOING ACTIVITIES Corrective actions are still in progress for secondary walls, base mats (including Containment Units 1 and 2 internal base mats),
single wall gaps (including certain areas in Containment Unit 2 that are still under construction) and double wall gaps.
In order to facilitate QC inspector training, the gap inspection requirements have been consolidated in a new procedure.
[
QI-QP-11.0-16. " Building Separation Gap and Condition Inspection".
N The methodology to be used for the remaining final inspections is the same as used for the inspections already completed and confirmed by the third-party to be effective. A third-party overview of these corrective actions continues as an added assurance that the QC process (utilizing the new procedure) will continue to be effective in verifying the acceptability of the final condition. Corrective actions associated with this effort will be completed prior to fuel load.
Should the situation arise where the Project is unable to completely remove debris in some location (s), an analytical evaluation will be completed to assess the acceptability of the condition.
In such cases, the third-party will review the analysis, with the results included in a supplement to this report.
The need to revise the FSAR has been assessed based on inspection findings. Section 3.8.5.1.3 has been submitted for revision in a subsequent FSAR update (Reference 9.21).
These changes are primarily in descriptive text and now reflect the an-built condition.
This particular change request is subject to appre al by SWEC as part of the verification effort being conducted fc.
Civil / Structural design work. Accordingly, any modifications to this change request, or any new FSAR change requests related to seismic separation gaps, will be overviewed by the third-party.
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1 RESULTS REPORT N
ISAP II.c i
i:
(Cont'd) 7.0 - ONGOING ACTIVITIES- (Cont'd)
Ongoing maintenance of the seismic gaps ('following completion of corrective actions _and final inspection) is to be addressed through Operations procedures. Third-party overview of the critical spaces program, including review of Operations procedures, will be I
undertaken as part of ISAP VI.a.
Engineering requirements related to the seismic gap are subject to verification under the SWEC Corrective Action Program in the Civil / Structural area. DAP will conduct an overview of the SWEC effort and will, in particular, review calculations related to the seismic gap.
Section 5.7 summarized the results of a focused NCR technical l
adequacy review. A comprehensive investigation of the adequacy of
~
NCR dispositions is being conducted by the. Project in a 1
self-initiated effort. The Project activities in this area will be overviewed by DAP.
O
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Two of the Out-of-Scope Observations discussed in Section 5.9 (Concrete Voids and Commodities Bridging Seismic Gcps) are being addressed by other Action Plans. The Project investigation of i
concrete voids will be overviewed by DAP (DSAP VII).
ISAP II.d will consider the significance of commodities bridging seismic gaps i
as part of its study of relative motion.
i 8.0 ACTION TO PRECLUDE OCCURRENCE IN THE FUTURE To ensure against debris intrusion in seismic gaps, measures were added to QC procedure QI-QP-11.0-3, " Concrete _and Mortar Placement Inspection", and now exist in QC procedure QI-QP-11.0-16 " Seismic Separation Gap and Condition Inspections". Primarily, these measures involve maintenance of flashing and/or seals with requirements for QC witness in instances where flashing or seal removal is necessary as part of some inspection or work activity.
To incorporate more definitive measures in conducting post-pour inspections for future concrete placement, QC procedure QI-QP-11.0-5, " Inspection of Concrete Repair", has been revised i
(Revisions 5 and 6).
These changes were reviewed by third-party l
and found to adequately address the concerns identified as a result j
of the root cause assessment presented in Section 5.11 (References l_
9.11 and 9.27).
To insure that the seismic gaps are maintained and inspected satisfactorily Operations procedures have been developed. The third-party will review these procedures as a task in ISAP VI.a.
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1 Page 42 of 56 RESULTS REPORT ISAP II.c
]
(Cont'd) i
9.0 REFERENCES
9.1 Safety Evaluation Report', Supplement 8, NUREG 0797, Related to the Operation of Comanche Peak Steam Electric Station Units 1 and 2, Docket Number 50-445 and 50-446, February, 1985.
9.2 SwRI Surveillance Procedure, "SwRI QA Overview Plan for Verification of the TUGC0 Inspection of the Seismic Gap Between Category I Structures and Non-Category I Structures",
i CPRT File Number II.c.3 (file includes Revisions 1, 2, 3, and 4).
9.3 TUGC0 Quality Instruction QI-QP-11.0-3, " Concrete or Mortar Placement Inspection", CPRT File Number II.c.Sa.(file includes Revisions 5, 6, 7, and 8).
l 9.4 SwRI Report, " Surveillance Report for the Investigation of As-Built Building Separation Gaps at Comanche Peak Steam Electric Station, Units 1 and 2", SwRI Project 8478, January 1986, CPRT File Number II.c.5c.
l 9.5 SwRI Report, " Interim Report on the Overview of the Final As-Built Seismic Gap Inspection at Comanche Peak Steam 4
Electric Station, Units 1 and 2", SwRI Project 8478, July 1986, CPRT File Number II.c.5c.
9.6 TENERA Memorandum, 6/18/86, from Pet'er Turi to File II.c.4f,
" Review of Historical Documents Related to Seismic Gap", CPRT File Number II.c.4f.
9.7 TENERA Memorandum, 8/28/86, from Peter Turi to File, " Review.
l of Additional Historical Documents Related to the Geismic Gap", CPRT File Number II.c.4f.
+
9.8 Gibbs & Hill Letter, Number GTN-71282, 3/6/86, "TRT Item II.c
- Seismic Gap".
9.9 Contact Log Sheet, 3/6/86, telecon between Peter Turi (TERA) and Anil Kenkre (Gibbs & Hill), " Clarification on GTN-71282".
9.10 Contact Log Sheet, 7/9/86, telecon between Peter Turi (TERA) and Pat Clarke (former B&R QC Manager), " Seismic Gap History".
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1 Paga 43 of 56 RESULTS REPORT J
ISAP II.c (Cont'd)
9.0 REFERENCES
9.11 Memo to file, 6/25/86, " Review of Project Procedures" CPRT File Number II.c.4f.
9.12 Contact Log Sheet, 9/3/86, telecon between Peter Turi (TERA) and Neil Britton (Quality Engineer), " Seismic Gap Protection".
9.13 Contact Log Sheet, 9/3/86, telecon between Peter Turi (TERA) and Dennis Murcer (Quality Engineer), " Seismic Gap Protection".
i 9.14 Contact Log Sheet, 6/9/86, telecon between Peter Turi (TERA) and Tom Brandt (QC Supervisor), "QC Inspection Procedures".
9.15 Wiss, Janney, Elstner and Associates, Inc., Report, Number 79656Q, 3/21/83, " Structural Response of Containment Vessel, Unit'No. 1, During Structural Integrity Test at Comanche Peak Steam Electric Station".
9.16 Gibbs & Hill Letter, Number GHCP-1362, 9/8/86, re:
inaccessible areas.
9.17 Gibbs & Hill Letter, Number GHCP-1775, 9/30/86, re: Type "C" inaccessible area.
9.18 Hansen, Holley, and Biggs Inc. Letter, 11/12/86, from Myle Holley to Peter Turi, "G&H Position re Type C Gaps (GHCP-1775)"
9.19 Hansen, Holley, and Biggs Inc. Letter, 11/18/86, from Myle Holley to Peter Turi, "G&H Position re Type A Gaps (GHCP-1362)"
l 9.20 Memo to file, 6/24/86, "II.c NCR Review", CPRT File Number II.c.4c.
9.21 CPSES FSAR Change Request, 5/30/86, GHCP-080.
9.22 Memo to file, 6/18/86, "FSAR Update Review" l
9.23 TENERA Memorandum, Number DAP-L-159, 10/3/86, from John Miller to John Hansel, "ISAP II.c".
l l
9.24 Gibbs & Hill Letter, Number GHCP-1678, 9/25/86, " Report:
Effect of Bridged Concrete as a Result of Unit 1 SIT".
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1 Page 44 of 56 W
)
RESULTS REPORT
(
ISAP II.c (Cont'd)
9.0 REFERENCES
(Cont'd) 9.25 Hansen, Holley, and Biggs Inc. Letter, 11/12/86, "Gibbs & Hill Report 'Effect of Concrete Bridging in Gap Locations et Containment U1 and Surrounding Interfaces as a Result of Unit 1 SIT' GHCP-1678".
9.26 SWEC Letter, Number SWTU-056, 10/22/86, re:
Issues Concerning Concrete Voids / Inadequate Consolidation.
9.27 Memo to file, 9/10/86, " Revision to QI-QP-11.0-5 (Rev. 6)".
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1 Page 45 of 56 RESULTS REPORT ISAP II.c (Cont'd)
Figure 1 Site Plan Viev l
l IEFELING WATER k
STORAE TAP 4(
KFUILING WATER rwt
$TORAE TAMC REACTOR MAME.tp MACTOR MAME&
WATER STORAM TAMC WATER STORAE T Aret CONTAINMENT j
CONTAINMENT UNIT NO. 2 LNT NO. I f
i AUXLIARY
$AFECUAA06 BUILD 0NG
$AFEGUAROS BUILDING BUILDING g
UNIT NO. 2 UMT NO. 8 YNTE O
STORAM Tape (
i I
I
$WITCHEAR
$WITOtEAR LNT M3. 2 COerdX LNT NO. B COPCEPGATE STORAE Tate (
TUIsleE TUIt#E SUILDING BULDIPC LNT NO. 2 UMTPC.I 1
4 O
1 x
Revision:
1 Page 46 of 56
-l RESULTS REPORT O
ISAP II.c (Cont'd) l Figure 2 Representative Mapping of Debris Size and Location for Area Along Containment Unit 1 Outer Wall i
G B
EL 918' - 4' EL 916' - 10' 9
~
g See Figure 3 I
\\....
7 I
l 9
e n
\\
e e
o
=
Revision:
I Page 47 of 56 RESULTS REPORT ISAP II.c (Cont'd)
Figure 3 Detail of Debris Size and Location (Use in conjunction with Figure 2) o
(;j;j
--" ::;i
!!i:::igi:
!.. :m.
- .x m=-
y.!.!!! iiii[
0 0
0 1
2 3
4 5 FEET 0
0 c2 O
o
Revision:
1 Page 48 of 36
,q RESULTS REPORT ISAP II.c (Cont'd)
Figure 4 Representative Mapping of Locations Requiring Gap Widening for Area Along Containment Unit 1 Outer Wall n.my g
o i
- u. ww I
I
[hP I
ex am k'
l e g
9 6
bs
{
b
$f A
i h$i l
@f 1
i i
q
.,jy
- See Figure 5
~
dk [^R$.5$
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m 9
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(
i
$1 k
% Q%g' l
AY
' m m~sy
~
p N___s Not Inspected v
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1 Page 49 of 56 RESULTS REPORT O
ISAP II.c (Cont'd)
Figure 5 Detail of Gap Widening Locations (Use in conjunction with Figure 4) s' - s 7/e*
s' - to 3/4*
//
/f et ass _to.
p
/A t
//
j i
/
Et esE* - o*
J LEEMk Areas requiring gap width adjusteent with associated aesteue concrete reenval requiremente.
I Ossed on ee-euilt inspection esseurosental Mr 2w l
O No Adjustment Required NOTE Winteue ess width requirement above elevation 882* - 8' is 1.075*.
I This requiresent la mAjoct te verification by SEC.
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I Paga 50 of 56 RESULTS REPORT ISAP II.c (Cont'd)
Figure 6 Diagram Showing Concrete Bridge and Broken Concrete Of Fuel Building Wall Near Containment Unit 1 1
NORTH 1
CONTAINNENT (UNIT 1)
VA...
iSy.Gc[.% *t
,6
-m ftg%,, jy.
2' OESIGN 6AP yn sg.
i 4.SQq,, 'Ly.*
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w..
. Q..%.m?ij.
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- c. ::'
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ti?.R CONCRETE BRIOSE LESENO:
l
- -- Outline of Intended Design Configuration
[*sih6k Concrete
[:'if.'@jI Dislodged Concrete 1
l
. *A
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1 Page 51 of 56
('J RESULTS REPORT
's\\
\\
ISAP II.c (Cont'd)
Table 1 Location in Section 5 of Action Item Resolution ACTION ITEM SUBSECTION LOCATION CPRT Tasks 1.
Inspect air gaps and identify 5.2 those that are out of compliance 2.
Correct out-of-compliance condition 5.3, 5.8 or demonstrate FSAR compliance 3.
Provide final as-built inspection 5.4 for corrected areas 4.
Provide analysis demonstrating no 5.6 effect of material in gap on seismic response Issue Resolution 5.
Reperform and document QC inspections 5.2 of air gaps 6.
Ensure that as-built conditions meet 5.3, 5.6, 5.8 derign requirements 7.
Asaess events leading to existing 5.5 condition and cause 8.
Remove debris or evaluate significance 5.3, 5.6, 5.11 to design basis 9.
Perform analysis using revised N/A (5.6) stiffness, as necessary
- 10. Review design evaluations on presence 5.6 of foam 11.
Issue instructions for removal of 5.3 debris
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RESULTS REPORT ISAP II.c (Cont'd)
Table 1 (Cont'd)
ACTION ITEM SUBSECTION LOCATION Issue Resolution
-(Cont'd) 12.
QC verification of the final as-built 5.4 condition
- 13. Revise engineering calculations N/A 14.
Review project procedures on 5.1 requirements for separation conditions 15.
Evaluate need to update FSAR 5.8 I
16.
Evaluate cause and decide on 5.12
()
further actions
- 17. Address construction housekeeping (see ISAP VII.a.7) methods 18.
Review conclusions on cause, 5.12 applicability to other areas, and acceptability of final as-built condition.
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f-g RESULTS REPORT
$' ')
ISAP II.c (Cont'd)
Table 2 Chronology of Events Date Document
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Comments FSAR Seismic load case defined by Sections 3.8.1.1.1, 3.8.4.5.1, and 3.7.b.2.8.
07/14/75 CP-QCP-2.4 Concrete pre-pour inspection procedure issued (no gap dimension check included).
01/29/76 RFIC-029 Field request to leave foam in place below waterstops due to difficulty in removal.
02/13/76 FPAR 110 Engineering approves RFIC-029 request saying foam may be left both below and above waterstop.
FPAR apparently misinterpreted by Construction to mean all foam may be left in place.
Engineering had
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apparently intended "above waterstops" to s
mean up to grade level only.
09/06/77 Telex GTT-1543 Gibbs & Hill notifies TUSI that practice of leaving foam in place above grade deviates from design intent and is unacceptable.
10/07/77 TUS-5012 TUSI instructs Construction management to 11/01/77 Halliburton Contract remove foam from specific areas (defined on 11/02/77 TUS-5019 sketch attached to TUS-5019), allows foam to remain for certain areas and allows a minimum of 1" air, gap for certain areas (no technical justification was documented for i
this " design change") already constructed.
TUS-5019 states explicitly that a 2" gap must be maintained in subsequent work.
12/05/77 CP-QCI-2.4-9 B&R procedure (temporary) to verify Halliburton removal effort and check minimum gap dimension. Only two checklists have been identified to date that relate to this inspection.
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ISAP II.c (Cont'd)
Table 2 (Cont'd)
Date Document Comments 02/19/78 IM-12939 Memo from Site QC Manager to Construction Management saying that, as a result of QC inspections, it is apparent that the Halliburton effort was not complete; both foam debris and less than design gap width are identified for a specific area; requests written response detailing actions and schedule to correct areas. No response from Construction has been identified to date.
07/12/78 QI-QP-11.0-3 Replaces CP-QCP-2.4, adds pre-pour verification of gap dimension, protection from debris intrusion.
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09/14/78 Inspection Reports Six reports were written, five "unsat"
'O 10/17/78 reports identified debris in ga,s, one of the five identified less than deui:- gap width.
04/13/83 NCR-C-83-01067 Open inspection reports were identified during building turn-over, were attached to NCR and routed to C/S Engineering.
04/17/83 NCR-C-83-01067 NCR closed using technically incorrect analysis.
04/26/83 TUS-4106 TUCCO Dallas Licensing response to TUQ-1622 (TUCCO QC memo to licensing group requesting review of NCR disposition) stating that disposition will satisfy FSAR commitments.
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Table 3 Sunusary of Related DIRs Related Report DIR#
Title Classification Sections D-0166 No Design Basis Calculations Observation 5.3, 5.7 D-0258 Effect of Cap Condition on Seismic Response Observation 5.6' D-0259 Effect of Gap Condition on Seismic Response Observation 5.6 D-0260 Local Seismic Displacements of Floors at Secondary Walls Observation 5.6 D-1346 Inadequate Building Gap Unsubstantiated 5.6 D-1347**** Frequency Calculations Lack Wall Discrepancy 5.6
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and Equipment Weights D-0004 Building Air Gap Dimension Unclassified 5.3, 5.11 Deviation 5.12.2, 5.12.3 E-0987*
Air Gap Between Concrete Structures Unclassified 5.11, 5.12.1, Deviation 5.12.2 E-1052*
Poor Workmanship Using "Rotofoam" Unclassified 5.11, 5.12.1, Deviation 5.12.2 E-1220*
Elastic Joint Filler Between Observation 5.6 Category I Buildings D-2141** Unsat Condition Not Documented Discrepancy 5.5.1 by QC Record D-2142**
No Procedural Requirements for Discrepancy 5.5.3 Post-Pour Gap Inspections D-2143** Misplaced or Lost QC Checklista Discrepancy 5.5.3 D-2144**
Inspections Conducted Contrary to Discrepancy 5.5.3 Procedural Requirements
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Table 3 Related Report DIRf
' Title Classification Sections D-2145** Unresolved Inspection Reports Discrepancy 5.5.3 Remained Open for 5 Years D-2132*** Commodities Eridging Seismic Gap Discrepancy 5.10.3 D-2133 Tolerance Allowables Not Specified Observation 5.12.2 on Drawing These DIRs were extracted during a review cf external source documentation and represent discrepancies identified by individuals outside of the CPRT.
Transferred to QA/QC Review Team.
Transferred to ISAP II.d.
- Transferred to DAP.
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