ML20199D481

Forwards Listed Info at Request of NRC to Supplement Info Provided in Re Large Bore safety-related Piping Calculations

ML20199D481
Person / Time
Site:	Crystal River
Issue date:	11/18/1997
From:	Rencheck M FLORIDA POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20199D486	List: ML20199D481 ML20199D543 ML20199D575
References
TAC-M99948, NUDOCS 9711200345
Download: ML20199D481 (14)

Text

i Ftrida Power 8%%.,,,u%T%mnCORPORATION November IS,1997 ,

3F1197-46 U.S. Nuclear Regulatory Commitsion Attn: Document Control Desk Washington, DC 20555-0001

Subject:

large Bore Safety-Related Piping Calculations (TAC No. 99948)

Reference:

FPC to NkC letter,3F1197-36, dated November 10, 1997

Dear Sir:

'lorida Power Corporation (FPC) is submitting the following documents at the request of the NRC to supplement information provided in the referenced letter.

A. FPC's Precursor Card (PC) 97-0048 regarding evaluation package and corrective action plan.

B. Letter to FPC from Wais and Associates, dated October 29,1996, " Evaluation of Piping and Support Design Documentation."

C. Letter to FPC from J.D. Stevenson Consulting Engineer, dated October 31,1997, " Overview of Safety Related Large Bore Piping and Piping Support Design and Construction Currently Existing at Crystal River-3 Nuclear Power Plant, Revision 0."

D. FPC's Large Bore Piping and Pipe Support Action Plan.

PC 97-0048 remains open and under evaluation. There are no commitments in this letter. FPC proposes to meet with the NRC next week to discuss FPC's plans to address questions raised by the NRC in our meeting on October 28, 1997, regarding the Large Bore Safety-Related Piping calculations.

If you have any questions regarding this submittal, please contact Mr. David Kunsemiller, Manager, Nuclear Licensing at (352) 563-4566.

Sincerely,

/ttw m -.

M.W. Rencheck, Director kDV i Nuclear Engineering and Projects .

MWR/cm 971120034S 971110 PDR ADOCK 05000302 Attachments P PDR xc: NRR Prc,W: Manager Regional administrator, Region 11 ]ll]l}]}la[\\((][

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Senior Resident inspector CRYSTAL RIVER ENERGY COMPLD 15760 W Power une Street . Crystal River. FL 3442$4708 - (352) 795 4 488 A Flonda % gress Company i ,)

ATTACHMENT A l FPC's Precursor Card (PC) 97-0048 i 1

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CLOSED card Number. -

y ' " ;;;na CR3 PRECURSOR CARD

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/./ ,237 UMT FPC Condition / Event Delgiption:

This Precursor is the result of Quality Assessment Audit 97-01 and reauires a response to (ATL).

We recommend that this precursor be classified as Level # B Short description of issue Review of Report 96-04-002, " Piping and Support Documentation for CR-3", written by Ed Wais and Associates at the request of Engineering, documents unanalyzed cu.-ditions potentially adverse to the safe and legal operation of CR-3. The rcport states that, "The individual conditions represent little safety significar.ce; however, many involved potentially important procedural, or quality problems. Over time-the cumulative effects of these design issues _ and lack of dscumentation could raise safety questions."

Detailed description of issue Examples of unanalyzed conditions that are identified in the Wais Report are:

1.- Instances where the combined thermal and seismic loading on rod hangers, in the upward direction, was not always considered during analysis. Where it was considered it was not always treated in a conservative manner.

2. Piping analysis did not always consider the effect of increased stress due to the local effects of welded attachments to pipes, such as trunnions.

3. A, thermal analysis was not required for systems below 150 *F. Several systems which operate above this temperature were not analyzed for thermal stresses.

4. Design analysis is not available to demonstrate the ability of non-standard anchors to perform there intended function.

5. CR-3 has many U-bolts intended as a two-way restraint but have not been analyzed for a horizontal load.

The resolution of these, and other issues documer.ted in the report have not been entered into the CR-3 corrective action process.

.CP-111, section 4.3.3.5 states, "When events or conditions involve suspected DBIs or unanalyzed conditions, the PCs should be graded as Grade 'B' and assigned to Nuclear .0perations Engineering for validation. .

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The report also states thst: f7-00/[

e '"There are no original support design calculations available at Crystal River. ...Therefore, it is difficult to verify the support capability to function as assumed in the pipe stress analysis."

o "The hard copies of the pipe stress calculations do not always represent the latest revision of the calculation. Use of these documents in review of the piping and support design could lead to incorrect conclusions.

o "... documents related to the work done in support of the response to Bulletin 79-14 were not accessible. . . . Retrieval of associated drawings or sketches was difficult..."

The three bulleted items above represent conditions contrary to 10CFR50 Appendix B, Criteria III, Design Control or Criteria VI. Document Control.

Sy1Rm(s)/ Tao Number (sh NA DenattmenlisLP_erforming e Activity:

QPD Immediate Actions Taken:

Discussed with Nuclear Engineering Supervisors Gnpiments/ Recommendations:

Provide recommendations

[ ] WR# [ ] REA#

Originator. Ron Shires Date: 1897 Department: Quality Programs Phone: 4731 (X) Request Copy of response MAC: SA2H I

If the following are suspected or kno'vn, check the appropriate space and HAND CARRY PC to NSM:

[F Reportable 364 OM4I

[ Operability concern [ ] ITS Violation

[ ] Unplanned Rad. Release [ ] Persont.el Safety concern Forward to Nuclear Shift Manager, NR3B For PCSC use oni;'

Grade: 3 . Date: /'k'h Rasp. Manager: fj RCT Leader:

Comments: ,

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GhDE 'C' APPARENT CAUSE S13 DIARY FORMAT --

PC Number: 97 0048 Page 1 of 2 --

WHO WAS INVOLVED?

Enginevring.

WHAT HAPPENED?

Report Number 96-04-002 " Evaluation of Piping and Suppen Documentation for Crystal River 3,"

created by Wais and Associates, Inc., identifies a nurrber of concems about the qualification status of piping analysis and pipe support calculations for safety related piping systems, and about the documentation ret.ieval system at CR3. The piping analysis and pipe support calculations were, in general, developed in the 1970's, so the originating organization or individuals are difficult to pinpoint. Many of the calculations were performed in the Architect-Engineer (A E) contractor's offices, and may still be archived in those offices, however they are not present on the CR3 site. The Precursor Card documents the concerns expressed in Report 96-04-002.

Inappropriate actions identified were:

1) Original design of pipe supports and piping analysis was performed without consideration of or in some cases with inconsistent treatment of certain design factors.

2) CR3 personnel did not evaluate and disposition emergent pipe support and piping analysis issues (such as U bolts used as two-way restraints) as they rose to the surface in the industry.

3) Documentation was not acquired, has not been maintained, or is not retrievable in the CR3 document management system reflecting the cunent engineering evaluations of oiping analyses and support designs.

o WHAT WERE THE INDIVIDUALS DOING?

1) Individuals performin5 the calculations were designing in accordx with standard practices of the time (1970's) and in conformance wita the Code of Record,(E a.1 1967). Some of the issues identified in Report 96-04 002 were not normally considered in that timeframe, but have been identified as industri issues since that time. Since the original calculations are not retrievable, it is difficult to conclude that errors exist in them, but the configuration documented in some of the design drawings seems to indicate that problems may exist in them. -

2) CR3 personnel were engaged in ongoing modification and design tasks, and not tuned in to the industry's struggle:, v,ith emerging issues. IEB 7914/02 evaluations did not cause a general upgrade of calculations at CR3 as they did at many other utilities.

3) This is difficult to ascerts;n due to the lapse of time since the original designs were done. It is speculated that the calculations were not requested from the contractor that performed them, and were therefore never entered into the CR3 document management system.

WHY DO YOU THINK IT HAPPENED?

1) Calculations were performed at a remote location by a contractor, and received no review by CR3 personnel. Personnel performing the calculations were under schedule pressure and received little training in requirements or techniques.

GRADE 'C' APPARENT CAUSE SUhDIARY FORMAT '

- PC Number: 97-0048 Page 2 of 2

2) CR3 personnel were engaged in ongoing modification and design tasks, and not tuned in to the ~

industry's struggles with emerging issues. Changes in state of the art for piping analysis and pipe support design were cet folded into CR3's calculations.

3) CR3 did not acquire the calculations at the time they were performed by the A E, which was not -

unusual in the industry in that timeframe. However, when CR3 terminated tneir association with the A.E. they did not require the A E to turnover the calculations for storage by CR3. His left CR3 without a defensible design calculation to support the qualifiestion of safety related piping -

and pipe supports.

CORRECITVE ACTION TAKEN OR PLANNED:

An assessment of the impact caused by the concems described in this PC on the design basis of CR3 has been performe i(Interoffice Correspondence from D.L. Jopling/F.X. Sullivan to D.T. Wilder dated January 29,1997 NOE 97 0063) and concludes that "...the defined conditions in Precursor Card' ,

1. 97 0048 do not constitu're a design basis issue..."

An action plan will be developed for implementation of corrective action addressing the identified

' design issues in an efficient and well-orchestrated program utilizing sampling and screening methodologies to the extent possible. His action is tracked by Crystal River Unit 3 Management

' Corrective Action Plan Phase II(MCAP !!) Rev. I number V. (Technical Issues) Item 1, sbe+306 and by IDRP ltem 6 and NOTES Item 24692.

Ac4/- 88" g (,/g/g Item D RC3 3 of the MCAP il commits to " Identify and monitor emerging industry issues in the regulatory area using the CR 3 monitoring / trending program", assigned tow /J. Baumstark with a Target Completion Date of 2/28/97.

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Item D RC4-1 of the MCAP Il commits to " Provide periodic case studies of regulatory issues and events, both intemal and extemal, to help provide parallels to CR 3 experiences" assigned to B.

Gutherman to be performed on an ongoing, periodic basis.

Attachments:

1) MCAP 11 Rev.1 Page 42

2) NOE 97 0068 Dated January 29,1997 From Jopling/Sullivan To D.T. Wilder

3) MCAP 11 Rev/1 Page 50 Prepared By: D.tiiWEY Date:-d/3/O

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Approved By:

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Date: M 7(5c'{97 (Q

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@l'00 W INTEROFFICE CORRESPONDENCE

@. Florida o er Nuclear Operations Engineerine OFFICE NA1E MAC 240-3576 TELEPHONE

SUBJECT:

Evaluation Of A Suspected DBI Identified By PC# 97-0048 M

TO: D.T. Wilder DATE: January M , 1997 NOE 97-0068 Nuclear Operations Engineering (NOE) has evaluated the concern addressed in Precursor Card # 97 0048. This PC was based on issues and concerns discussed in a report developed by Wais and Associates. This report was an " Evaluation of Piping and Support Documentation for Crystal River 3". The following discussion is intended to provide the basis for the determination that the issues defined in Precursor Card # 97-0048 and the Wais report do not constitute a Design Basis Issue or an Unanalyzed Condition. In other words, the defined conditions will not result in systems, structures or components being rendered incapable to perform their safety function in preventing or mitigating design basis events. For piping systems, this is interpreted to be the loss of pressure boundary integrity and/or the ability to deliver rated flow.

To some degree, this conclusion is based on historical date. Specific portions of piping systems have been requalified or evaluated in the recent past. These analysis efforts have not identified a piping system that was incapable of meeting design basis requirements. Some of the qualification efforts addressed issues that are similar to those discussed in the Wais report and none were found to represent a Design Basis issue.

In addition to the experience basis to support the assertion that the issues actdressed in the Wais report do not represent a DBI, the specific issues identified in the report will

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be address in the following discussion.

DISCUSSION OF TECHNICAL ISSUES IDENTIFIED IN PC #97-0048

1. Uplift on Rod Hangers - Rod supports are acceptable for the support of dynamic loads and computer analysis results are a sufEciently reliable indication of whether or not tension can be maintained in a rod. The normal design process allows for the utilization of a rod hanger in dynamic conditions if the net downward load from sustained loadings, i.e. dead weight and thermal, is greater than the analyzed seismic uplift load thereby provhiing an indication that uplift (compression on the rod) will not occur or in the event that uplift may occur, the rod hanger is designed for the compressive load (buckling). It should be pointed

NOE 97c0068 Page 2 out that seismic support loads are much more conservatively derived than dead weight and thermal support loads. This means that even when the predicted downward sustained load is equal to the predicted seismic load, the actual seismic load will be much less than the actual downward sustained load and uplift will not occur.

Even though earthquake experience data is not a part of the design basis for piping systems at CR3, it does provide a clear indication that single acting supports such as rod hangers are effective in the mitigation of seismic effects.

Thia also establishes a basis for concluding that this issue has no significant consequences to the DBI evaluation.

2. Local Stress Effects Paragraph 121.3.2 of ANSI B31.1, which is the Code of Record for CR3, addresses the requirements for integral type structural attachments to process piping. The paragraph simply states that " consideration shall be given to the localized stresses induced into the piping component by the integral attachment." No explicit stress criteria is required. Other codes of the same nature and vintage (Paragraph NC-3645 of ASME B&PV) as ANSI B31.1 simply require that " external and internal attachments to the piping shall be designed so as not to cause flattening of the pipe, excessive localized bending stresses or harmful thermal gradients in the pipe wall."

The consideration given to integral attachments in the design phase for CR3 is not apparent. Typically, the designers and design engineers sized lugs and other integral attachments based on experience and performed no deterministic stress analysis. The resulting stresses are considered by the Code to be secondary in nature and result in localized deformations,i.e. flattening and/or local yielding, but are not considered to affect the pressure boundary integrity or the fluid transport capability, therefore they are judged not to represent a design basis issue.

3. Thermal Analysis - The temperature below which an explicit thermal analysis was not required was defined at CR3 as 150 degree F. Several systems which had temperatures in excess of 150 degree F. may not have been analyzed. The establishment of a cut off temperature for the performance of a thermal flexibility analysis varies from licensee to licensee. It generally varies between 100 degrees F to 200 degrees F. Previous licensing activity at another nuclear plant, concerning the restart of the plant, established a cut off temperature of 200 degrees F. This would indicate that CR3's 150 degree cutoffis arbitrarily low and the failure to evaluate the thermal loading identified in the Wais report may be acceptable. Additionally, the thermal analysis applied at CR3 did not take into account the flexibility of the supports and restraints. If a thermalloading problem were to be identified in a reanalysis, support flexibility will reduce the loading (the inclusion of hanger flexibility will affect the results of the seismic

NOE 97 0068 Page 3 analysis). Based on engineering experience and a knowledge of the flexibility of CR3 piping systems, there is essentially no potential for thermalloading resulting in a design basis issue.

4. Non Standard Anchors This item of the WAIS report concerns itself with two separate issues. The first issue is the local stress effects similar to the issue described in Item 2 above. The discussion provided in Item 2 is applicable for this issue as well. The second issue deals with the appropriateness of the mathematical model used in the piping analysis. The concern is that the physical anchor does not represent a rigid restraint as assumed in the mathematical model. This will result in a change in the overall stiffness matrix for the system, Stresses and loads will redistribute across the anchor if the actual stiffness of the anchor were used in the mathematical model as opposed to a rigid anchor. As discussed above, this will generally reduce the thermal stresses and loads. The effect on seismic loading is diflicult to predict. Generally, the seismic loading on the anchor will distribute to several adjacent supports when anchor flexibility is included in the analysis. CR3's seismic loading is low and the capacity of most supports is significantly greater than the seismic loads currently indicated by existing analysis. As a result, load changes due to anchor flexibility are unlikely to result in a design basis issue.

5. U Bolts - There has been significant work performed in the determination of allowable side loadings for U bolts. Attached is a copy of a standard applicable to TVA as an example of the industry position applicable to U bolts. This standard establishes design values for unidirectional horizontal loads and an interaction methodology for biaxial (tension / shear) loadings. These load ratings were established basad on testing and included a deflection criteria. U bolts are considered to be component standard hardware typical of that supplied by any pipe support vendor, i.e., Power Piping, Bergen Patterson. The TVA data is considered to be appropriate for making an design basis issue determination. A review of this data indicates a substantial capacity for horizontalloadings. For purposes of the DBI review, the emergency load rating is considered to be.

acceptable and do not indicate a concern.

6. Cumulative Effects - The items identified above are representative issues for piping and pipe supports for CR3. Individually, these items have been assessed to be of nominal significance relative to an impact on the CR3 design basis, however, some concern exists relative to the cumulative effects of these items.

The specific items defined in Precursor Card #97-0048 in and of themselves are not necessarily cumulative, Items relative to the consideration oflocal stress effects (Items 2 and 4) occur only in local proxinity to each welded attachment to the piping. Unless the welded attachments are in proximity to each other, the resulting stress effects are not cumulative (superimposable). Item 3 deals with

- NOE 97c0068 Pege 4 4

thermal flexibility and is compared to a discrete allowable stress. This allowable '

stress is different thnn the allowable stress for Items 1 and 5.

Items 1 and 5 could produce some potential for cumulative effects since they both-deal with the appropriateness of the riathematical modelin predicting seismic loadings on the piping system. Seismic is not a controlling design loading at . ,

CR3. A review of the seismic floor response spectra indicates the great majority of safety related piping is subject to OBE loadings ofless than 1.0g peak accelerations.

Based on the abcve discussion, it is concluded that the combined effects of the identified issues does not represent an design basis issue.

The precursor card also identifies a number of anomalies relative to the retrievability of documentation on nuclear safety related systems and components. These items may represent conditions contrary to 10CFR50, Appendix B but are considered to be outside the scope of this design basis issue evaluation / determination. The inability to retrieve qualification documentation to demonstrate compliance with the design basis can also be considered to represent an non conforming condition. This condition should be included in the corrective action plan.

Based on the engineeringjudgments expressed above and in light of the historical data associated with similar issues reported for piping and pipe supports and the resulting evaluations, it is concluded that a condition does not currently exist relative to the identified issues that would constitute a design basis issue.

Even though this DBI determination concludes that the defined conditions in Precursor Card # 97 0048 do not constitute a design basis issue, there are documentation and technicalissues that constitute a potential for non conforming conditions. As a result, an action plan to address non conformance will have to be developed. This plan could require the performance of an analysis / evaluation studies of these potential non.

conforming conditions to demonstrate compliance with the design basis documents. If during the performance of a reanalysis effort a condition is identified that repre:ents a suspected design basis issue, a separate evaluation / determination will be performed on the identified condition. Should the operability evaluation conclude there is a significant compromise to safety, then the DBI would be reported per 10CFR 50.72

- requirements.

There are a number of technic'alissues that the action plan will need to address to assure design / commitment compliance. The more significant issues include:

(1) Thermal analysis (cutoff and operating modes to include environmental temperatures) e - , -

NOE 97-0068 Page 5 (2) Overlap criteria (3) Rod hanger uplift (4) Local stress effects (welded attachments)

(5) Strut / snubber angularity (clamp qualification)

(G) U boltload ratings (7) Load distribution on dual snubbers / struts (8) Allowable nozzle loadings Positions should be developed for each of the key technicalissues and a limited scope sample of selected piping analyses performed. The limited scope sample would establish a higher level of confidence to support the assertion that the CR3 piping conGgurations meet all design code requirements. A screening process may be required to be implemented on the entire population of piping analyses and/or pipe supports calculations should any significant issues be revealed by the sample.

The screening process would be applied to all applicable qualification documentation if the results of the sample do not confirm a high confidence. All significant issues reveled by the results of the sample will be considered as outliers and the entire population screened for these outliers. Outliers should be identified and graded to determine whether the individual outlier or the accumulation of outliers for a specific pipe stress analysis or pipe support configuration requires reanalysis or whether reanalysis can be deferred until reanalysis is required for other reasons. These determinations would be made based on the existing stress margin, other existing unanalyzed conditions and the number and type of outliers identified during the screening process.

Once an action plan is developed and specific issues addressed a sample reanalysis effort for selected piping models should be undertaken. The results of the sample reanalysis efforts, combined with the developmental efforts should be evaluated. If the results of the efforts support the assertion that CR3's piping is in compliance with code requirements cdditional analysis could be undertaken as deemed necessary. If however the sample analysis were to identify areas of concern the scope of the reanalysis effort would need to be expanded.

O O&-- N '

%CG go,e D.L. Jopling, S pervisors F.X. Sullivan, Manager Nuclear Operations Engineering Nuclear Operations Engineering attachments: TVA-Design criteria '

cc: S. Chernenko G. Halnon P. Peterson A. Petrowsky Records Management

A D C.% 1 e i

.. INDEPENDENT DE51CN AEVIEW PANEL RICCMME.NDATIONS V. Technical lasues

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Responsible Target Compleuon Recommendation Manager "Date

1. - FPC should complete its efforts to better danfy the, ,

bases and approach to hancling piping analysis and piping support design basis issues. (IDRP 6)

Disposition: Accepted. /nterim action taken to bring in Ed Wais to review the current piping and support F.X Sullivan M"

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2. The panel re:ommends and CR.3 had decided to F'###' A'U*~

ins: ail design upgrades to the HPl system to enhance M ' IN### U}

operating margin in the event of certain postulated " "" Nf #

transients. (IDRP 8) (v/J/f U '" M3 '

Disposition: Accep ed, ppc is plannjns to install F. X Su!!ivan F'"Refu'el 11 HPI crossover pipes and casitating venturis in Refuel 77.

3. The panel recommends and CR 3 has decided to conduct a thorough investigation to determine why similar balance of. plant design features are limiting at CR.3 and not at TMI 1. (IDRP 9) .

Disposition: Accepted. FPC will conduct the F. X Sullivan 6/30/97 recommended review.

4. FPC should complete their review of the July Framatome Technologies (FTI) report and take any appropriate actbn. (IDRP 10)

Disposition: Accepted. Review of the July report is F. X Sullivan 6l30/97 directly connected with recommendation #3 abow.

FPC will enter the subject report into the vendor inicemation program to control the review.

S. Obtain controlled copies of the Fmmatome/B&W tpe 52 reference documents for use by station engineering personnel with rppropnate propnetary information protection. (IDRP 15)

Disposition: Accepted. FPC will obtain site copies ). Colby 2/1/97 of(or site acce.ss to) the B&W proprietary design documents. There i: an apparent error in the above recommendation in that the type S2 documen:s referred to should be type 32 documents.

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PC 97-0048 Referenced Document (NOE 97-0068, Pg. 3, Item #5)

TVA - Design of U-Bolt Clamps for Piping and Tubing

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GENERAL' P'S D M- DS-C1'.2.6

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ATTACHMENT'At DESIGN- 0P :U-BOLT CLAMPS FOR PIPING /AND TUBI *:r; i -- ,

-TABLE OF CONTENTS --

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• 1.0~ GENERAL-~. .:. .-. . . . . . .<...-. . . . . . . . . .

A2 1.1. Applicability.. . . . .. .. .-. . . - . . . . - . . . - . = . A2 1.2 Definitions . . .. . . . . . . . . . . . - .- . . . . :A2 2.0 DESIGN PHILOSOPHY . .-. . . .. . . . . . . . . . . .

A3 1

3.0 U-BOLT DESIGN ih0CEDURE . . . . . - . . . . . . . . . A3-4.0= REFERENCES . .. . . . . .. . . . . .- . . . . . - . A4 LIST OF FIGURES Figure 1 U-bolt Installetions A5 LIST OF TABLES Table Title Pm 1

Allowable' Horizontal Unidirectional Load (Condition 1 1 4) A6 2'

Allowable Horisontal Unidirectional Load (Condition 2) A7 3

Allowable-Horizontal Unidirectional Load (condition 3) A8

• 4 Allowable Vertical Unidirectional Load (All Conditions) A9'

-5 Installation-Torque Values A9 6 Allowable Load Increase Factors A10 Table Notes A10 4

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, GENERA L P8 DM DS-C1.2.6 I

1.0 GENERAL This design standard covers the design of U -bolt clamps used 'in support of piping and tubing. Allowable loads presented herein are based on manufacturer's information and comprehensive tests performed by Tennessee Valley Authority (TVA) and interpreted to satisfy the code requirements identified in this document.

1.1 -Applicability This design standard is applicable to all piping and tubing designs qualififed to the provisions of Design Criteria e B FN-50-C-710 7 a t andWattsBarNucgrowngants FerrygyclegrPlantUnits1-3andSequoyah' ear ts 2 1.2 Definitions U-bolt--l U-shaped rod with threaded ends that fits around a pio. and is attached to a supporting member. (See Figure 1.)

e-bolts may be either vender-supplied or field fabricated. The following terminology is applicable to U-bolt installations:

Slack Support - Nuts are installed on each leg such that a 1/16-inch gap exists between the nuts and support steel.

(See installation condition 1 of Figure 1.) Nets are to be locked in position with an approved locking device as defined by General Construction Specification G-53 (G-53).

Stiffened Support - The U-bolt is installed with two nuts on each leg and a 1/16-inch gap between the surfaces of the U-bolt and the supported pipe. (See installation condition 2 of Figure 1.) Nuts away from the pipe are to be snug tight in accordance with the provisions of G-53 after the nuts adjacent to the pipe have been installed in the proper position. For design purposes, this is the preferred condition for new installations where horizontal leading is involved.

Stiffened Support with Shim - The installation is identical with " stiffened support" except a 1/2" (maximum) thick shim is added beneath the pipe to allow installation of the inner nuts on the U-bolt (see installation condition 3 of Figure 1.)

i

.\ 2

I GENERAL- P8DM '

DS-C1.2.4 l Snug Support - The installation is identical with " slack support" except nuts are tightened against support structure - i to remove the 1/16-inch gap and nut torque may vary from zero-to a torqued. condition. This condition.shall be avoided for'

=: new-installations. -

Spacer Plate Detail - The installation (see Figure 1) is identical to installation condition 2 except a spacer plate  ;

having holes to accomodate the U-bolt is added. The spacer '

plate must be welded to the supporting structure unless the-nuts away from the pipe are torqued to the levels specified in Table 5.

2.0 DESIGN PHILOSOPHY The allowable loads for U-bolts presented in this design standard are based on reference 4.7, which implements the provisions of ASME Section III 1974, Subsection NF, including W74 addenda. Load ratings are further limited by a 1/8-inch deflection criteria.

Tables 1 through 4 list allowable unidirectional loads for U-bolt clamps. The allowable loads in the following tables are only justifiable when field installation conditions corruspend with those associated with each table.

3.0 U-BOLT DESIGN PROCEDURE The following procedure shall be followed to quality U-bolt clamps for which allowable unidirectional loads are given in Tables 1 through 4

1. From Tables 1 through 4, determine the allowable unidirectional loads for the U-bolt in each cirection for which there is a design load.

2. The U-bolt is qualified if the following interaction formula is satisfied for all loading conditions.

h + v i 1.0 H V where h and v are design lo ::s in the horizontal and vertical directions as shown on figure 1.

R and V are the allowable unidirectional loads from the appropriate tables.

Note:

For U-bolte installed on piping and tubing with design temperatures less than 650* F. allowable loads listed in tables 1 through 4 may be increased by the' appropriate K value listed in table 6.

s-A3

GENERAL PS DM DS-C1.2.6

?

4.0 REFERENCES

4.1 3rN and S;N - Lateral and vertical U-bolt testing program, test plan No. CEB-BN-1041 R0 (B41 880429 003).

4.2 TVA Calculation Package, CEB-SQT-236 RO, " Pipe Support Load Rates of Various Configurations of U-bolts" (B41881222 015).

4.3 Browns ~ Ferry and Sequoyah Nuclear Plants Lateral and Vertical U-bolt Testing Program SME-STR-88-007A (B46 880727 004) One Volume and SME-STR-88-007 B&C (B46 880902 001) Four Volume Set I-IV 4.4 Brevns Ferry Nuclear Plant - Memorandum from Frank Van Meter to R. O. Barnett, Dated 2/25/82, " Browns Ferry Nuclear Plane Units 1 Standard U-bolt Clamps - Load Deflection Tests" (CSB 820225 301).

4.5 Browns Ferry Nucleer Plant - Memorandum From Frank Van Meter to R. O. Barnett, Dated 11/10/83, " Browns Ferry Nuclear Plant - Standard U-bolt Pipe Clamp Test for Axial Lead Cipacity (CSB 831110 302).

4.6 " Browns Ferry Nuclear Plant - Evaluation of Standard U-bolt Pipe Clamps", Report No. CEB 85-06 (B41 850510 001). t 4.7 TVA Calculation Package, CD-Q0000-890269, " Load Rated Capacities of the U-Bolts" (B22 890213 102).

4.8 1983 ASME Section III Division I, Appendix I, Table I-13.1

( --

A4

I- GENERAL P8D4 DS-C1.2.6 vcRrtCAL LOANNo -

h

? Hontz0N TA L

= LOACING 1 1 1 '

C: ""T % '

' ~

C 3

~

~

wrs seu a uicazo a amou en a macun uxxas erwx lilSTALLAT)CN CONDITION 1 SLACK SUPPORT I

p m I

, v;: y( y tv-

,e

/r

) - , r "

"1 7 "

1 .

1/2" Maximum I

r-1 1 .

1

\

f L. J L_ J

/7 I J L _ J u- _

INSTALLATION CONDITION 3 INSTALLATION CONDITICN 2 STIFFDlE SUPPORT (W/ SHIM)

STIFFDED SUP80RT

--u' I. ..

ya r- 1 r- 1 1 . I I .

1 L_ J

) J L-J 9 y '

INSTALLATION CONOITION 4 SPACER PLATE DETAIL SNUG SUPPORT U-BOLT INSTALLATIONS FIGURE 1 1

A3

4 GENERAL PSDM DS-C1.2.6 .

.i.

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' TABLE 1-Allowable'Iforizontal Unidirectional Load ( Qsj

. Condition'1'and 4 y f I l l

k #

1 1 I

g.i L J L-J m **"'

"" mstuuta coata 4 postAu.atcps Cons 0ticM i StrUC $UFFORT SWSNT

' Pipe Size U-Bolt Normal / Upset Emergency Red Sz. Condition Condition 1/2" 1/4" 231 30f 3/8" ** 296 395 3/4" 1/4" 196 260 I 3/8" 405 539 1" 1/4" 135 180 1

3/8" ** 369 491 1-1/2" 3/8" 665 709

• 2" 3/8" 529 645

• 2-1/2" 1/2" 1137

• 1137

• 3" 1/2" 921 1076

• 4" 1/2" 772

• 772

• 6" 5/8" 332

• 332

• 8"- S/8" 203

• 203

• 10" 3/4" 318

• 318 *

• Load is limited by 1/8" deflection.

• • Allowables for Conditien 1 only

{ , . .

O A6

.I

, GENER.AL PS D MI DS*C1.2.6 TABLE 2 Allowable Horizontal Unidirectional Lead (Ips) - Condition 21

_ l x

y t g. .

. r- 1 r-i .

t i e 4, .s I- J '

DETALLATW CDSTW t strenes nevent Pipe Size U-Bolt -Normal / Upset Emergency Rod Sr. Condition Condition 2-1/2" 1/2" 911 1211 3" 1/2" 936 1245 4" 1/2" 850

• 850

• 6" 5/8" 569

• 569

• 8" 5/8" 392

• 392

• 10" 3/4" 419

• 419 *

• Load-is limited by 1/8" deflection.

e l ,o l

8, w .. ..

99- ooyr GENERAL PSDM Ds.C1.2.6 i

TABLE 3'A11ewable Horizontal Unidirectional load'(Lbs) - Condition 3

) (* 1 i

1 .

, I" 7 i i .

1/2" Hamirim i

/T V .V' segint.LAtitus CDelRTION 3 .

rimisi sumurt (w/sutx)

Pipe Size U-Bolt Normal / Upset Emergency Rod Sr. Condition Condition t

1/2" 1/L" 180 240 3/8" 383 509 3/L" 1/4" 121 161 3/8" 490 651 1" 1/4" 62 93 1-1/2" 3/8" 353 423

• 2" 3/8" 385

• 385 *

• Load is'11mited by 1/8" ceflection.

k A8-

m . . . . - . - _ . . . -- _ _ _ _ . _ _ _ _ . _ _ _ . . . . _ . . _ . _ . . . _ . . _ . _ _ . _ . .

97- Owg

. GENERAL PSDM' Ds.C1.2.6 r i

\

TABLT 4 Allowable Vertical Unidirectional Load (Lbs) - All Conditicns ._

U-Bolt Pipe Normal / Upset Emerger.cy Rod Sz' -- S i z e - Condition Condition 1/2" 1/4"- 750 3/4" 564

1. .

3/4" 1292 1717 3/8" ~~

1-1/2" /

2n 2"

2-1/2" 2471 3287 1/2" 3n 4..

5/8" 6" 3954 5259 g ..

3/4" 10" 5633 7492 TABLE 5-Installation Torcue values - For Spacer Plate U-Bolt Torque Rod Size (Ft. Lbs.)

1/4" 4

-3/8" 12 1/2" 30 5/8" 60 3/4" 100 4

9 I A9

.. n .-

GENERAL PSDM DS-C1.2.6' TABLE 6 Allowable load Increase Factors (K) - All Conditions Temperature: "T"

(*T) 100 '200 300 A00 500 600 '650 K 1.37 1.25 -1.22 1.18 1.lt 1.02 1.00 LTor ~ calculating allowables H' or V' at temperature "T", equal to the design temperature of the pipe, H' = HK and V' = VK TABLE NOTES

1. All-U-bolts are carbon steel with a minimum specified tensile strength of r l

-50 ksi un1-ss noted. A11ewable loads for stainless steel are the same as for carbon steel.

2. Allowable loads are applicable for service temperatures up to 650'F.

3. Axial allowables;are not a part of this design standard and should not be

.used for design.

4 Vertical allowable loads, Table-4, are applicable to all installation conditions.

i 5.- Allowable loads are also applicable to U-bolts fabricated from -

continuously threaded rod.

6.- 'U-bolts installed one oversize with respect to the supported pipe have the same allowable loads as for a normal application. This is applicable to installation condition 4 for piping 12" in diameter and for horizontal and vertical loading only.

7. A spacer plate having holes to accommodate the U-bolt may be used in accordance-with the detail shown on Figure 1. When used, allowable loading is in accordance with condition 2 and nuts must be torqued in accordance with Table 5, unless the spacer plate is welded to the structural member.

8. Tables 1 through a provide lower bound conservative load ratings based upon TVA generated test data. These load ratings may be adjusted on a case specific basis to reflect actual material. In this case, the adjustment shall be justified consistant,with the methodology of reference 4.7 and documented in the pipe support calculation.

9. Table 6 is based on values for yield point at various temperatures from reference 4.8. ' Interpolation between temperatures is permitted.

10. - The Faulted Condition shall be-evaluated using Emergency Condition -

'Allowables. ' '

~,

6 A10

. . /; rr,::, n 1 g;~ 3 6, b .* -t .

snadequate perf:rmance monitonng and trending from a regulste,ry comp!cnce psrspa; e

' Focussing on the right issues in the right pnonty. t Obtaining first hand informadon on issue content and sensitMty. ~'

• i Obtaining real time informadon on emerging issues . -

Eliecuve implementaden of the safety evaluadon process. -

Corrective Actien*

Action Responsible Target Completion Date Manager.

D RC21. . Ensure a Licensing representative B. Cutherman Completed

.. is part of the graded precursor screening team to provide 10/21/96 regulatory perspective to the corrective action program. .

D.*a 2. Assure appropnate levels of C.Boldt 11/1/97 management meet with the SRI on L Kelley a weekly basis at his convenience B. Hickle for open, candid communication. ~

D RC3 3. Identify and monster emerging L Kelley/

industry issues in the regulatory 2/28/97 J. Baumstark area using the CR 3

• monitoring / trending program.

D RC4-8. Provide periodic case nudies of B. Cutherman On going on a regulatory issues and events, both periodic basis Intemal and extemal, to help provide parallels to CR 3 expenences. ,

~

1

'O w 22.i m

(

ATTACHMENT B Letter to FPC from Wais and Associates Dated October 29,1996

" Evaluation of Piping and Support Design Documentation" i

i i

l l

l l

1 l

l l

9 9 Wahand Associates,Inc.

Letter No. 09 04 002 3 i

October 29,1996 l Florida Power Corporation Crystal River Nuclear Plant '

15760 W. Power Line Street Crystal River, FL 34d28 6708 Attention: DanJopling MailCodeNAlE

Subject:

Evaluation of Piping and Support Design Documentation

Dear Dan,

Pleasu find enclosed the report regard:ng the subject evaluation. The report covers the approach, observations and recommendations resulting from this review. The helpful consideration and cooperation of the Cry 3ta' River 3 personnel during the conduct of this evaluation was much appreciated. We look forward to working with you again.  ;

If you have any questions or need additionalinformation, please contact me at 770 242 9525.

Very tmly yours Edward A. Wais EAW:noe

. Enclosure' 3845 Holcomb Bridge Road, Suite 300 Norcross. Georgia 30092 (770) 242 9525 FAX (770) 409 0530

._.