U-600197, Renews 841025 Request for Termination of Overinsp Program for Electrical Hangers (Cable Tray Hangers & Conduit Supports).Technical Justification for Request & Responses to 850411 Questions Encl

Renews 841025 Request for Termination of Overinsp Program for Electrical Hangers (Cable Tray Hangers & Conduit Supports).Technical Justification for Request & Responses to 850411 Questions Encl

ML20133M281
Person / Time
Site:	Clinton
Issue date:	07/26/1985
From:	Hall D ILLINOIS POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
U-600197, NUDOCS 8508130071
Download: ML20133M281 (42)

Text

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,1 U-600197 L37-85(07 -26 )-L

)M 1 A.12 0 ILLINOIS POWER COMPANY CLINTON POWER STAT!ON. P.O. BOX 678. CLINTON. ILLINOIS Cin7 July 26, 1985 Docket No. 50-461 Mr. James G. Keppler Regional Administrator Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Subject:

Illinois Power (IP) Company Request for Concurrence to Remove Additional Commodities from the Overinspection Program

Dear Mr. Keppler:

On October 25, 1984, Illinois Power Company (IP) met with members of the USNRC Region III staff to discuss changes in the scope of the IP Overinspection Program. This meeting was docu-mented in NRC Report Number 50-461/84-37(DRP). During the meeting, IP proposed terminating the Overinspection Program for electrical hangers because there was a separate 100% reinspection already being conducted of work done prior to July 26, 1982. The NRC suggested that, as an alternative, IP should consider delet-ing the Baldwin Associates (BA) Quality and Technical Services (Q&TS) 100% reinspection of electrical hangers and completing the Overinspection Program. IP has reviewed this matter. Con sider-ing the results of the Overinspection Program and the positive contribution of the Q&TS reinspection, IP has concluded that terminating the Overinspection Program remains the most desir-able course of action.

Therefore, IP hereby renews its request for NRC concurrence to terminate the Overinspection Program for electrical hangers (cable tray hangers and conduit supports). The technical justif-ication for this request is contained in Enclosure 1 to this letter.

The NRC letter dated April 11, 1985 (J. G. Keppler to IP Attn: W. C. Gerstner), stated that the questions and comments, concerning the February 1985, IP report entitled "Results of Quality Programs for Construction of Clinton Power Station" and contained in Enclosure 3 to that NRC letter, should be addressed by IP prior to any future proposal to terminate the Overinspec-tion Program for additional commodities. Enclosure 2 to this letter contains IP's answers to the NRC questions and comments in Enclosure 3 to the NRC's April 11, 1985, letter.

8508130071 B50726 1E PDR ADOCK 05000461 f

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~t IP believes that the enclosures provide a complete base of information for an NRC Region III decision on the . subject IP request for concurrence at the earliest possible time.

Sincerely yours,

. . Hall Vice President JEK/j sp Enclosures cc: Director, Office of I&E, USNRC, Washington, D.C. 20555 B. L. Siegel, NRC Clinton Licensing Project Manager NRC Resident Office Illinois Department of Nuclear Safety Allen Samelson, Assistant Attorney General, State of Illinois

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ENCLOSURE-1 TECHNICAL JUSTIFICATION FOR IP'S REQUEST FOR NRC CONCURRENCE TO TERMINATE THE OVERINSPECTION PROGRAM FOR ADDITIONAL COMMODITIES

References:

1) IP Report, " Update to Results.of Quality Programs for Construction of Clinton Power Station", April 1985.

2) NRC letter (J. G. Keppler to IP Attn: W. C.

Gerstner), dated April 11, 1985.

3) NRC letter (J. G. Keppler to IP Attn: W. C.

Gerstner), dated July 2, 1985.

~This IP request for NRC concurrence to terminate.the Over-inspection Program covers electrical hangers (cable tray hangers

.and conduit supports).

.The basic' data and evaluations that support this request have been greviously provided to NRC in reference 1. Reference 1

. reported the results of the Overinspection Program for all commodities as of December 31, 1984, and included engineering evaluations of the safety significance of all nonconforming conditions identified by the Overinspection Program through that-date.

NRC letter, Reference 2, forwarded questions on IP's March

-29, 1985, request for concurrence to-terminate the Overinspection Program for Piping and Mechanical Supports and stated that IP should provide answers to the NRC questions and comments con .

tained in Enclosure 3 to that letter prior to any future requests to terminate the Overinspection Program for additional commod-ities. The following Enclosure 2 provides the response to applicable.NRC questions and comments in Enclosure 3 to Reference-

- 2.

NRC letter, Reference 3, provided the NRC's concurrence to 4 terminate the:Overinspection Program for Piping and Mechanical Supports. However,.for two reasons, the NRC did not concur with.

i. IP s request to terminate Overinspection of a commodity based on

~the L Both of the NRC' generic for s reasons pre-established criteria nonconcurrence proposed concerned the by IP.

quantity of items L of a given type that would have to be reinspected before con-1

- sideration could be given to terminating reinspection of that type of. item (IP proposed criterion 1). Specifically, the NRC

.did not agree that, generically, reinspection of 10,000 attri-L

butes or 5% of the total number of items in the plant would l . provide a sufficient base of information upon which a decision on l- termination of the reinspection of that type of item could be l- based. Therefore, IP has restated this criterion, indicating i only that a sufficient number of reinspections will be performed L

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s to support a conclusion of high confidence that the results of

~

reinspections are representative of overall quality for a spe-cific commodity. IP will provide the NRC with substantiating data on an item-by-item basis.

The technical justification for this request is provided below, as follows:

• Part A - A statement of the criteria for termination that incorporates the NRC position set forth in Reference 3.

• Part B - The pertinent results of the Overinspection Program as of December 31, 1984, for the commodities that are the subject of this request.

• Part C - The basis for the conclusions that the termination criteria are met for each commodity, and that IP's request should be granted.

A. The Termination Criteria

. All of the following criteria shall be satisfied before the reinspection of a safety-related commodity under the Over-inspection Program is terminated.

1. A sufficient number of reinspections have been con-ducted to provide high confidence that.the results of reinspections are representative of overall quality for a specific commodity.

2. In the aggregate, the reinspections for a commodity did not identify a significant number of nonconforming attributes . This criterion will be satisfied if the rate of conforming-attributes is at least 95%.

-3. The reinspections for a commodity did not identify any nonconformanc~e which had safety-significance with generic implications. A safety-significant noncon-formance is defined as a nonconformance which, were it to have remained unidentified by the Overinspection Program, could have resulted in the loss of capability ,

of a structure, system, or component to perform its intended safety function. This criterion will be satisfied by an engineering evaluation, similar to that Results of Quality Programs for performed for the Construction of Clinton Power Station".

t 9

B. The Results of the Overinspection Program through December 3T, 1984 The results of the Overinspection Program through December 31, 1984, are reported in Reference 1. The Field Verifi-cation results pertinent to Criterion 1 above, are presented in the following table:

Table 1 Reliability Items Safety Based on Total Reinspected With Significant 95%

2 Commodity Plant By FV NCRs NCRs Con fidence Electrica{

Hangers 39,356 4,438 2,156 0 > 99%

fIncludescabletrayhangersandconduitsupports Reliabilities are calculated using the equation:

R = 1 - 2. 99 5 where, n

R = Reliability at 95% confidence level assuming an infinitely sized lot n = Number of items inspected Based on the number of attributes inspected for each commod-ity, Figure 1 shows that the uncertainty associated with the reinspections are low, and further inspections are not expected to significantly reduce this uncertainty. In addition, Figure 2 shows that the 95/95 criterion, which is the basis for Overinspection Program sample inspection, is also satisfied for electrical hangers.

Based on the number of items reinspected, the associated low uncertainties and the fact that the 95/95 criterion has been satisfied, IP Criterion 1 for termination of reinspection has been met.

The Field Verification results pertinent to Criterion 2 above are presented in the following table:

Table 2 Attributes Non conforming Conformance Commodity Inspected Attributes Rate Electricgl 10,922 Hangers 381,062 97%

1 Includes cable tray hangers and conduit supports m

FIGURE 1 A

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DEPEhDENCE OF UNCERTAINTY IN NONCONFORMANCE UPON THE NUMRFR OF ATTRIBUTES INSPECTED s.o- Us- AT 95% CONFIDENCE LEVEL i S

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For electrical hangers IP Criterion 2, 95% conformance is satis-fied.

In regard to Criterion 3 above, the engineering evaluations of all nonconformances identified by the Overinspection Program, as reported in Reference 1, Chapter V and Appendix D, show that none of the nonconformances were safety signif-icant, and thus Criterion 3 is satisfied. Additional qualitative and quantitative information concerning these evaluations is presented in Enclosure 2, IP Responses to Enclosure 2 NRC Question A.3 and Comment C.3. The results of the engineering evaluations are summarized as follows:

Table 3 Number of Safety 2 Number of Number Significant Reliability Nonconforming of Nonconforming Based on Commodity Conditions NCRs Conditions 95% Confidence Electricgl Hangers 11,635 2,448 0 > 99%

Includes cable tray hangers and conduit supports 2

Reliabilities are calculated using the equation:

R = 1 - 2.995 where, n

R = Reliability at 95% confidence level assuming an infinitely sized lot n = Number of items inspected C. Conclusions As shown in Table 1 above, the criterion for extent of inspection is satisfied for electrical hangers.

As shown in Table 2 above, the criterion for conformance rate (95%) is satisfied for electrical hangers.

As shown in Reference 1, Chapter V and Appendix D and Table 3 above , the criterion for safety significance (no safety significant nonconformances) is satisfied for electrical hangers.

These results and conclusions are based upon reinspection of a substantial portion of the plant for the subject commod-ities. The engineering evaluations provide high confidence in the ultimate capability of plant components to perform F

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); -their int' ended safety function. The results of the Over-inspection Program through December 31, 1984, confirm the quality of Clinton Power Station construction in general and the subject commodities in particular. NRC should grant F: IP's request to terminate the Overinspection Program for these commodities.

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ENCLOSURE 2 ILLINOIS POWER RESPONSE TO NRC QUESTIONS IN~ ENCLOSURE 3 TO THE NRC'S APRIL 11, 1985, LETTER CONCERNING REQUESTS TO TERMINATE THE OVERINSPECTION PROGRAM FOR COMMODITIES OTHER THAN PIPING AND MECHANICAL SUPPORTS This enclosure responds to the NRC questions and comments regarding the Illinois Power (IP) Report entitled, Results of Quality- Programs for Construction of Clinton Power Station, . Chapter V and Appendix D. The NRC comments and questions are quoted directly from Enclosure 3 of the NRC letter.from J. G. Keppler to IP, attention W. C. Gerstner, '

dated April ll, 1985,-and are followed by the IP responses.

Where - two or more questions are .related to a single topic, these are grouped together and a single IP response is provided.

ENCLOSURE 3 NRC COMMENT A: IP should provide answers to the applicable questions contained in Enclosure 2 for.

commodities other than piping and mechanical supports.

Provide . justification -for those questions determined to be not applicable.

-IP RESPONSE TO ENCLOSURE 3 NRC COMMENT A: IP's answers to the NRC questions in Enclosure 2 to NRC's April 11, 1985 letter for electrical: hangers are set forth below. The NRC questions in Enclosure 2 are denoted below as " ENCLOSURE 2 MUD QUESTION" and are quoted below before each IP response.

It is noted that the NRC Questions as quoted relate to piping and mechanical supports. IP responses provide information relative to electrical hangers which are the subject of this request.

ENCLOSURE 2 NRC COMMENT A.1: One- of the objectives of the Overinspection-(OI) Program is to prove that the struc-tures, systems, and components (SSCs) at the Clinton Power Station (CPS) are properly installed in order to assure safety of operation. The data presented in references 2 and 3 concerning giping and mechanical supports are defined in terms of attributes which are sub-elements of plant SS Cs . Plant SSCs are composed of varying quantities of these attributes, depending upon commodity and degree of complexity. In addition, some of these attributes do not necessarily act independently in achieving the safety function of the SSCs to which they apply (i.e., some attributes of a pipe support would have a greater impact on the integrity of that support when taken together than when considered separately). )

O-ENCLOSURE 2 NRC QUESTION A.1: Provide OI program results for piping and mechanical supports (including confidence

' factors) in terms of plant SSCs rather than SSC sub-elements.

IP RESPONSE TO ENCLOSURE 2 QUESTION A.1: The table below provides the requested data.

Data as of December 31, 1984 Reliability Items Safety. Based on Total Reinspected With Significant 95%

Commodity Plant By FV NCRs NCRs Confidence 2 Electrica{

Hangers 39,356 4,438 2,156 0 > 99%

Includes cable tray hangers and conduit supports Reliabilities are calculated using the equation:

R = 1 - 2. 99 5 n

where:

R = Reliability at 95% confidence level assuming an infinitely sized lot n = Number of items inspected

• t*******************************

ENCLOSURE 2 NRC COMMENT A.2: Reference 2, attachment 2, provides IP's response to open item 461/84-37-01. That response is data in terms of percent complete and number of attributes inspected'for safety related piping and mechan-ical supports.

ENCLOSURE 2 NRC QUESTION A.2: Provide more detailed information concerning piping and mechanical supports which forms the basis for the data arovided (e.g., total linear feet of safety related large aore piping and the number of feet actually inspected; total number of safety related

_ pipe supports and the number actually inspected, etc. ) .

IP RESPONSE TO ENCLOSURE.2 NRC QUESTION A.2: The informa-tion is provided in response to Enclosure 2 NRC Question A.1 above.

1 i

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s-ENCLOSURE 2 NRC COMMENT'A.3: The data presented in refer-ences 2-and 3 related to piping and mechanical supports are presented quantitatively with only limited qualitative information. This presentation does not provide a meaning-ful. basis for an independent reviewer to judge the actual significance of OI findings.

ENCLOSURE 2 NRC QUESTION A.3: Provide additional qualita-tive data related to piping and mechanical supports which was the basis for statements contained in references 2 and 3 regarding the significance of OI findings (e.g., refer to the Byron report provided to IP at the meeting in Region

-III last October 25: Exhibit C-2, page 8 of 15, Table CE-9). The response should consider.all applicable attri-butes inspected.

ENCLOSURE 2 NRC COMMENT B.3: Because of the dependent nature of certain sub-elements (attributes) of plant SSCs, the actual confidence achieved in terms.of the ability of an individual SSC to perform its intended safety function has not been clearly established. For example, a pipe support may be composed of a concrete foundation, a base plate, anchor bolts, nuts, several structural shapes arranged in a defined geometry, interconnecting welds, connecting rods, U bolts, clamps, etc.. These individual parts of the support have attributes defined by IPOI. IP has demonstrated a high degree of confidence in the confor-mance- of these individual attributes. However, the support must'act as a unit in order to perform its safety function.

ENCLOSURE 2 NRC QUESTION B.3: Can IP demonstrate a high degree of confidence in piping and mechanical supports when the individual attributes are arranged as a unit (or item),

considering the dependency of certain attributes, using-the

' data'obtained to date under the OI program? Provide the detailed' analytical results.

ENCLOSURE 2 NRC QUESTION'B.4: Considering the response to item [B.3] above, is the conformance criterion sufficient when applied to piping and mechanical supports without restriction?

IP RESPONSE TO ENCLOSURE 2 NRC QUESTION A.3, B.3 and B.4:

The objective of the engineering evaluations performed on the nonconformances was to determine the potential signif-icance to plant safety had the nonconforming condition (s) been undetected by the Overinspection Program. These engineering evaluations demonstrated that the identified nonconformances would not have impaired the ability of the components to perform their safety related design function.

The design margins of each component, considering the reported nonconformances, werc' determined to be within the specified design limits.

The engineering evaluations considered the potential effect that all identified nonconforming attributes may have had on the components. This evaluation addressed both singular and cumulative effects (attributes which may not act independently) , as appropriate for the nature of the reported nonconforming attributes and the affected compon-ents. For example, if two or more nonconforming attributes affected a load bearing weld, the net effect of all noncon-forming attributes in reducing the weld capacity was considered.

The results of the engineering evaluations on a component basis have been divided into the four categories described below, and are summarized in the table following the description of the four categories. These categories have been developed in order to quantify the significance of the nonconformances with respect to the design or design margins.

Category A The nonconforming attribute (s) reported on the components are acceptable because they do not affect the structural integrity or functional capability of the component. These items are not significant with respect to the plant design and, therefore, have no effect on the plant safety.

Category B The nonconforming attribute (s) re7orted on the components resulted in an acceptable reduction in the functional capability or structural integrity of the component. The components so affected have been divided into Categories B1 and B2 to quantify the significance of the nonconforming attribute (s) as follows:

Category B1 The reported nonconforming attribute (s) resulted in a potential reduction in capacity or component design margin of less than 10%.

Category B2 The reported nonconforming attribute (s) resulted in a potential reduction in the capacity or component design margin equal to or greater than 10%.

Category C The nonconforming attribute (s) resulted in a reduction in functional capability or structural integrity beyond that allowed by the plant design basis. There are no components in this category.

l l

l SIGNIFICANCE OF IDENTIFIED NONCONFORMING CONDITIONS EXPRESSED IN TERMS OF CAPACITY OR DESIGN MARGIN REDUCTION:

Data as of December 31, 1984 Category B1 Category B2 Category C Tot al Category A Commodity (No Impact) (<10%) (310%)

438 (18%) 0 (0%) 2448 (100%)

Electrical Hangers 1137 (46%) 873 (36%)

CATEGORY A NONCONFORMANCES Nonconformances that were classified as Category A were those that could be shown to have no effect on an item's ability to meet its design basis parameters Typical or tolerances noncon-by comparison with the current design basis.

formances identified by the Overinspection Program that resulted in a Category A classification are cosmetic weld defects and minor documentation and installation errors.

Documentation errors consisted mostly of missing or damaged component identification markings and documentation discrep-ancies on design drawings. Where component identification markings were missing or not legible, proper identification was established or recovered from other files. Documenta-tion discrepancies involving incorrect fabrication or construction drawings were, in most cases, previously reviewed for design impact by the originating design organi-zation and decisions were made to utilize the as-installed configuration ("use-as-is") and make the appropriate correc-tions to the design drawings to reflect the "as-built" condition. These types of documentation errors were clas-sified as Category A, since the reported nonconformance did not impact the component's compliance with the design basis.

Installation related nonconforming attributes consisted mainly of tolerance nonconformances, wrong welds, or wrong hardware. The nature of these nonconformances was such that they did not cause a reduction in the strength of the support and, hence, were classified as Category A.

CATEGORY B NONCONFORMANCES Nonconformances classified as Category B involved those nonconformances which required the comparison of the dis-crepancy to the weld capacity or component design margins.

In many cases detailed engineering analysis and calcu-lational comparison to the original design were required.

~

Discrepancies.that resulted in potential. weld capacity or-component-design margin reductions of less than 10% are classified as. Category B1 and those with capacity / margin reductions equal to or greater than 10% as Category B2. The most prominent examples involved welding discrepancies such as undersized welds, lack of fusion, overlap, slag inclusion and undercut. These nonconformances were determined to reduce the strength of the connection, but they did not affect the capability of the weld to satisfy design loading conditions, therefore, a Category B classification resulted.

Installation and damage nonconformances also often resulted in a Category B classification. Installation discrepancies included tolerance and wrong hardware nonconformances which resulted in an increase in stress on a structural component.

Damage discrepancies included dents, gouges, and cuts which resulted in a reduction of the component s capacity.

However, in all cases of installation and damage discrep-ancies the structural component was able to satisfy the design basis requirements.

As noted in the above table, four hundred thirty-eight (438) electrical' hangers had nonconforming attributes identified that potentially could have reduced their capacity or design margin by equal to or greater than 10%. The majority of these nonconforming attributes were welding discrepancies.

Welding nonconformances resulting in Category B2 classifica-tions cn1 conduit supports and cable tray supports primarily involved undersized welds, overlap,-undercut, and slag baclusion. These nonconforming welds were evaluated by comparing the actual weld stresses (excluding affected areas) to code allowable stresses.

Most of the remaining nonconformances that resulted in a B2 classification were caused by improper installation or damage. These conditions required an analysis which cem-pared the stresses in the as-built component to code allow-able stresses. In no case were the actual stresses in the as-built component greater than code allowable stresses.

-IP RESPONSE TO ENCLOSURE 2 NRC QUESTION B.3: As noted in I the response to Question A.3 above, cumulative effects were considered where appropriate. Therefore, IP has demon-strated a high degree of confidence in the components that are the subject of this request (See response to Enclosure 2 NRC Question A.1 above).

IP RESPONSE TO ENCLOSURE 2 NRC QUESTION B.4: Yes. Con -

sidering the responses to Enclosure 2 NRC Questions A.3 and B.3 above, the conformance criterion proposed in IP's letter  ;

of March 29, 1985, is sufficient when applied to the elec-trical hangers.

1 ENCLOSURE 2 NRC COMMENT A.4: The data presented in refer-ences 2 and 3 related to piping and mechanical supports does not provide sufficient relevant information (e.g. , numbers of SSCs inspected, numbers of inspections performed, and OI fLadings broken down by discipline, by building and eleva-tion, and by old vs. new work).

ENCLOSURE 2 NRC QUESTION A.4 : Quantify OI results for piping and mechanical supports in terms of numbers of SSCs inspected, and numbers of inspections performed broken down by discipline, by building and elevation, and by old vs. new work.

IP RESPONSE TO ENCLOSURE 2 NRC QUESTION A.4: The data requested are provided on the following charts, except for the craft disci7 line information requested. No specific data is available for this information. However, for electrical hangers, the work is essentially all performed by boilermakers and electricians. As is demonstrated by these charts, the results of the Overinspection Program provide a representative sample of all buildings and elevations containing the components that are the subject of this request. This, coupled with the number of inspections performed, demonstrates that a large random sample has been reinspected and therefore the results represent the quality of these components at CPS.

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- 0VERINSPECTION PROGRAM INSPECTIONS BY:

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ENCLOSURE 2 NRC COMMENT B.1: Ten thousand attributes inspected does not appear to be a consistent criterion which can be meaningfully applied to different plant SSCs. For example, a simple beam installation may consist of 150 sub-elements (attributes) while a complex beam installation may consist of 800 or more attributes. Thus the 10,000 attributes criterion may be satisfied by inspecting as few as 13 complex beam installations or 67 simple beam instal-lations. Neither number of installations appears to be an adequate basis for obtaining reasonable assurance in the total population of safety related beam installations at CPS. This comment is equally applicable to piping and mechanical supports.

ENCLOSURE 2 NRC QUESTION B.1: Quantify the minimum number of mechanical supports and the minimum number of feet of large and small bore pipe which would have to be inspected in order to achieve the 10,000 attributes criterion. Is that number an adequate basis for obtaining reasonable assurance in the total population of similar plant SSCs?

Provide the technical basis for your determination.

IP RESPONSES TO ENCLOSURE 2 NRC QUESTION B.1: Considering the NRC's position on generic termination criteria and IP s response in Enclosure 1 to this letter, this question is no longer germane.

ENCLOSURE 2 NRC COMMENT B.2: Five percent of the items (SSCs) inspected may be a reasonable basis for extrapolating confidence in the total population of similar SSCs in-stalled, provided that:

1) The total population of similar SSCs is sufficiently large, or

2) An adequate level of confidence can be established with smaller total populations of similar SSCs on some other basis.

3) Provided the 5% sample is a random sample of old work (pre-July 1982).

The basis for any determination regarding small populations of similar SSCs nust be clearly established.

ENCLOSURE 2 NRC QUESTION B.2: Can IP demonstrate taat required confidence levels will be achieved using the 5%

criterion even when small total populations of SSCs are inspected under the OI program?

t Considering IP RESPONSE the TO ENCLOSURE NRC's position on generic 2termination NRC QUESTION B.2:

criteria and IP's response in Enclosure 1 to this letter, this question is no longer germane.

ENCLOSURE 2 NRC COMMENT B.5:

Criterion C (related to defense in depth) appears to be a valid criterion, subject to the veracity of the engineering evaluations performed (see comment C.2).

ENCLOSURE 2 NRC QUESTION B.5:

Can IP demonstrate that this criterion is met for piping and mechanical supports when the engineering evaluations performed for safety significance conform to the stated premises (refer to comment C.I. for premises)?

Considering IP RESPONSE TO ENCLOSURE 2 MRC QUESTION B.5:

the information provided in response to Enclosure 2 NRC Questions A.1, A.3, and B.3 above and to Enclosure 2 NRC Question C.1 below, IP concludes that the criterion has been fully satisfied for electrical hangers.

• * ******************************* In the engineerint evaluations ENCLOSURE 2 NRC COMMENT C.1:

documented in reference 2, attachment 2, third page last paragraph, and in reference 3, Chapter V, paragraphIP takes credit for f C.2.b.2)(f) depth, and (j ),

and quality of which may be undefined.

the scope, For example, the reference 2 paragraph states in part:

Installation nonconformances on pipe supports involved loose or incomplete hardware instal-lation, incorrect adjustment of supports, lack of clearance or interference, and construction tolerance non-conformances, Each nonconforming condition was evaluated to y determine if the nonconformance was of a type that would be specifically examined Conse-in (f subsequent preoperational testing.

quently, these nonconformances were not significant because they would not have been left unidentified and uncorrected if the Overinspection Program had not been performed (emphasis added).

This methodology for evaluating construction deficiencies is not in accordance with 10CFR50.55(c), and does not appear to be consistent with a premise stated in reference 2, attachment 2, first page, last paragraph, as follows:

i .. .

Although S&L evaluated each nonconformance -}

identified by the Overinspection Program to j-determine whether it was safety significant, it should be emphasized that most of the -

nonconforming items have been reworked in Ji accordance with applicable design drawings -

and specifications and the remainder have been determined to be acceptable as they are. ij Consequently, the evaluations below were i performed to determine the safety signifi- p cance of the nonconformances assuming they  ;

had been left uncorrected (emphasis added). z In addition, this methodology appears to depart from a dh stated premise in reference 3, Chapter V, paragraph C.2.a., ))

ig as follows:

For purposes of this report, a safety signif- 'f -

icant nonconformance is defined as a noncon- ":"

formance which, were it to have remained unidentified by the Overinspection Program _

95 (emphasis added), could have resulted in the loss of capability of a structure, system, or 7 component to perform its intended safety -

function.

Reference 3 adopts the above premise by reference. Y I _

ENCLOSURE 2 NRC QUESTION C.1: Does IP intend that engi- j neering evaluations of 01 findings conform to theIfrequire- 4 l

ments of 10CFR50.55(e) and the above premises? so, what 1

are the results of IP's evaluations of OI findings concern-ing piping and mechanical supports when performed in 9 accordance with the stated requirements and premises? j a

The engineer-

! IP RESPONSE TO ENCLOSURE 2 NRC QUESTION C.1: l ing evaluations for electrical hangers did not take credit a l a

, for any future activities. Therefore, this question does 2

not apply to electrical hangers. ,

ENCLOSURE 2 NRC COMMENT C.2: Reference 3, Chapter 5, pages. V-9 through V-10, states: t

For cases in which one NCR documented noncon- -

formances on different items or in which one

item contained nonconforming attributes of differing natures (e.g., loose bolt and arc strike), separate evaluations of the impact _'

of the nonconforming attributes on each item -

were conducted to ensure that all possible e adverse impacts were addressed. _

m

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t

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7 This statement seems to imply that multiple nonconforming conditions identified on a single item were treated sepa- -

rately.

If this is what was intended ENCLOSURE 2 NRC QUESTION C.2:can IP justify the methodology used by the statement above,in light of the dependent nature of certain attributes (a discussed in A.1. and B.3. above)?

As discussed IP RESPONSE TO ENCLOSURE 2 NRC QUESTION C.2:

in the response to Enclosure 2 NRC Question A.3 above, both

. i riate, for the nature of the reported nonconforming attri-sing r butes and the affected components.

j f Reference 3, Chapter 5, -

ENCLOSURE 2 NRC COMMENT C.3 : Arc Strikes, does not differentiate .

F paragraph C.2.b.2) (c), A severe arc  :

"[ between superficial and severe are strikes.

strike may reduce piping wall thickness substantially and/or include a localized crack, usually at the bottom of the pit created by the strike.

S Provide both qualitative and g ENCLOSURE 2 NRC QUESTION C.3:

J y_ quantitative analytical results from the engineeringevaluation .

? and mechanical supports.

j' As discussed  :

IP RESPONSE TO ENCLOSURE 2 NRC QUESTION C.3: -5 J in the response to Enclosure 2 NRC Qucction A.3 above, arc k i strikes were evaluated to determine their potential effect (

on cable tray supports and conduit supports. In no case  ?;

were any localized cracks reported that were a result of an  ;

are strike. Arc strikes were In reported on six hundred forty all these cases, the reported ,

(640) electrical hangers.  ;;

t are strikes had little or no impact on the affected compon- -

p.'

ent. No reported arc strikes on electrical hangers were classified as Category B2 or Category C.

M+ .

r NUMBER OF COMPONENTS J

WITH REPORTED ARC STRIKES .

f -- (Data as of 12/31/84)

Number of Electrical Hr,3gers Significance 640 Category A and Category B1 (< 10%)

0 Category B2 (210%)

0 Category C

s ENCLOSURE 2 NRC COMMENT C.4: Reference 3, Chapter 5, paragraph C.2.b.2)(d) provides the engineering evaluation of missing or incorrect identification markings. That evaluation does not appear to consider the potential impact of missing or incorrect identification on the correct performance of operating activities (operations , main-tenance, and surveillance).

In addition, there is no indication as to the type of criteria applied by S&L in evaluation of missing or incor-rect material markings. This is of particular importance in view of the substance of IP's 10CFR50.55(e) reports 55-84 -02 and 55-84 -18.

ENCLOSURE 2 NRC QUESTION C.4(1): Provide the following additional information related to engineering evaluations performed on missing or incorrect identification markings:

(1) The results of evaluations performed related to the impact of missing or incorrect component identification markings (related to piping and mechanical support components) on the correct performance of operating activities.

IP RESPONSE TO ENCLOSURE 2 NRC QUESTION C.4(1): As is discussed in IP's February 1985, Report entitled "Results of Quality Programs for Construction of Clinton Power (Results Report), Cha Station" "S&L evaluated all cases of missing, incorrect, or damaged identification markings to assure that the proper identity had subsequently been established. In all cases, the correct items were installed. Therefore, it was determined that there was no impact on plant performance or operating activities."

ENCLOSURE 2 NRC QUESTION C.4(2): The criteria used by S&L in dispositioning nonconformance reports dealing with missing or incorrect material identification markings on piping and mechanical supports.

IP RESPONSE TO ENCLOSURE 2 NRC QUESTION C.4(2): Thirty-eight (38) electrical hangers were initially identified as having components lacking material traceability. In most cases, the material traceability was subsequently re-established by reinspection or through existing documen-tation. In a few cases, calculations were performed to verify that the material used was adequate to meet the code allowable stresses. No further criteria for acceptance of these nonconformances were required.

n

e' DiCLOSURE 2 NRC COMMENT C.5.a

. S&L form 350-A (seismic) states that the actual design attachment of equipment to a structure must be simulated in mounting the equipment for a test.

ENCLOSURE 2 NRC QUESTION C.5.b: Has IP considered the impact of OI findings on the results of seismic testing and analyses performed? What are your results?

IP RESPONSE TO ENCLOSURE 2 NRC QUESTION C.5.b: S&L form 350-A (Seismic) does require equipment to be seismically tested or analyzed to verify that the actual design attach-ment-of'the equipment to the structure is. properly simu-lated. .This requirement does not apply to electrical hangers. For these supports, a dynamic analysis is per-formed which includes the appropriate seismic response spectra. The seismic loading for each support was con-sidered in each overinspection evaluation where a reduction in strength resulted from a nonconforming condition. For all electrical hangers evaluated, the sup' ports were deter-mined to be acceptable within code allowa31es.

. ENCLOSURE 2 NRC QUESTION C.5.c: Has IP quantified the impact of engineering analyses performed under the Over-inspection Program in terms of reduction in safety margin on piping and mechanical supports? What are your results?

IP RESPONSE TO ENCLOSURE 2 NRC QUESTION C.5.c: There has

'been no reduction in safety margin, in terms of IP's definition of safety significance, for the components that

.are_the subject of this request as determined 3y the engineering evaluations. Quantified results for capacity and design margin for each commodity are provided in the response to Enclosure 2 NRC Question A.3 above.

ENCLOSURE 3 NRC COMMENT B: Reference 3, Chapter V, page V-24 at the top of the page IP states that based on IP's ,

experience with the Overinspection Program, it is IP's opinion that the BA inspectors have applied the (AWS) inspection criteria even more conservatively than the IP inspectors, which has resulted-in a lower conformance rate for field verification inspections than for departure inspection.

ENCLOSURE 3 NRC QUESTION B: What data has IP evaluated to confirm its opinion and to assure that all inspections were conservative?

j l

f o e

J i

f The NRC ques-IP RESPONSE TO ENCLOSURE 3 NRC QUESTION B:

tion references the discussion from the bottom of page V-23 I

to the top of page V-24 of the February 1985, Results Report. That discussion opinei that the lower conformance than depar-rate for FV inspection (95.4% on the average) ture inspections (97.6% on the average) shown on Table V-3 was attributable to a more conservative application The Updated of the AUS Results Report, welding criteria by BA FV inspectors. Table V-3, shows essentially identical and departure inspections conformance rates for FV (97.5%) The (97.6%) based upon data through December 31, 1984.

opinion expressed in the February 1985, report has been At the same time, eliminated from the April 1985, update.

IP believes that inspections underThis the Overinspection is borne out by the Program have been conservative.

results reported in both the February In and the April reports particular case and of the results of NRC inspections. provided welding, NRC Inspection Report No. 50-461/84-28 the results of NRC's independent inspection of welds reinspected by the IP Overinspection Program and concluded that the OI program inspections were conservative.

Reference 3 Chapter V, page V-24 at the bottom of the page; IP concludes that perfor-ENCLOSURE 3 NRC COMMENT C: 7 mance of 100% overinspection in accessible structural steel will assure that the quality of all structural steel is acceptable.

Provide the engineering basis ENCLOSURE 3 NRC QUESTION C:

for this extrapolation in accessible structural steel.

S&L's engineer-IP RESPONSE TO ENCLOSURE 3 NRC QUESTION C:

ing evaluation showed that none of the nonconformancesidentifie This fact, which is based steel were safety-significant.

upon reinspection results for approximately 60% of the structural steel in the plant for FV reinspections, can logically be extended to conclude that there is high confi-dence in the quality of the inaccessible structural steel.

While IP places primary reliance on the engineering evalu-ation for this conclusion, the reliability calculated This lends for statis-structural steel is greater than 99%.

tical support to the engineering conclusion. S&L is also performing evaluations of inaccessible structural steel.

These evaluations postulate that the types of noncon-formances identified on accessible structural steel are The effect of found in inaccessible structural steel.

these nonconformances on the inaccessible structural steel items is then evaluated and, to date, no safety significant conditions have been identified .

l

0 i

ENCLOSURE 3 NRC COMMENT D: Reference 3, Chapter V, page V-27 at the second paragraph; IP has identified a declining trend in the quality of electrical equipment installations and electrical cabic installations through the OI program.

ENCLOSURE 3 NRC QUESTION D: What steps have been taken to correct the trend in the first line quality control in-spections for new electrical work.

IP RESPONSE TO ENCLOSURE 3 NRC QUESTION D: The February Results Report showed an FV conformance rate of 84.6% for new electrical equipment and 94.1% for new cable based on July 31, 1984, data. The corresponding conformance rates for December 31, 1984, data or 97.7% and 95.9%, respec-tively. The apparent trend, which was probably attribut-

.able to the limited size of the population of attributes reinspected in these areas as of. July 31, 1984, no longer appears significant in the larger data base.

ENCLOSURE 2 URC COMMENT E: Reference 3, Chapter V, Tables V-4 and V-6; there are several inconsistencies and typo-graphical errors in these tables which have not been corrected by IP. For example, the type of Table V-4 is "NONCONFORMANCE RATES BY TYPE OF COMMODITY" whereas the data aresented in terms of conformance rates, similar to taile V-6 which has the correct title. Other examples are the lines beginning with " Cable Trays" and

" Instrumentation" which contain typographical / clerical errors.

IP RESPONSE TO ENCLOSURE 2 NRC COMMENT E: IP acknowledges the inconsistencies and typographical errors cited in the NRC comment. Additionally, IP is in the process of con-ducting an extensive re-review of data used in reporting the results of the Overinspection Program. This re-review has been completed for piping, mechanical supports and electrical hangers and is in progress for other components.

Changes in the information provided in the " Updated Results Report" are being identified as a result of this re-review.

These changes will be reported when the re-review is complete. Based on experience to date, IP believes that none of the chenges will affect any of IP's conclusions regarding the results of the Overinspection Program.

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