ML20111C443
| ML20111C443 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 03/12/1985 |
| From: | Woolever E DUQUESNE LIGHT CO. |
| To: | Knighton G Office of Nuclear Reactor Regulation |
| References | |
| 2NRC-5-041, 2NRC-5-41, NUDOCS 8503150400 | |
| Download: ML20111C443 (10) | |
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'Af h_Q' Q 2NRC-5-041 (412) 787-5141 (412)923-1960 Nuclear Constructior Division Telecopy (412) 787-2629 Robinson Plaza, Buikling 2. Suite 210 Pittsburgh, PA 15205 March 12, 1985 United States Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:
Mr. George W. Knighton, Chief Licensing Branch 3 Of fice of Nuclear Reactor Regulation
SUBJECT:
Beaver Valley Power Station - Unit No. 2 Docket No. 50-412 Response to Mechanical Engineering Branch Question 210.34
REFERENCE:
2NRC-5-031, dated February 21, 1985 Gentlemen:
This letter forward s a revised response for Mechanical Engineering Branch Question 210.34.
It incorporates the supplementary informat ion submitted in Letter 2NRC-5-031 dated February 21, 1985, with the current FSAR Amendment 7 response.
Upon your concurrence, this revised responne will be included in a future FSAR amendment.
DUQUESNE LIGHT COMPANY By e.
E. J foleve r4) /
Vice President JJS/wjs A t t achment cc:
Mr. B. K. Singh, Project Manager (w/a)
Mr. G. Walton, NRC Resident Inspector (w/a)
SUBSyRIBED AND SWORN Tg BEFORE ME THIS
/rY/L DAY OF 'J/7a,/v 1985.
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Notary Public ANITA ELA!NE REITER, NOTARY PUBLIC ROBINSON TOWNSHIP. ALLEGHENY COUNTY 31 MY COMMISSION EXPlRES OCTOBER 20,1984
United States Nuclear Ragulatory Connaission ifr. G::orge W. Knighton, Chief Response to Mechanical Engineering Branch Question 210.34 Page 2 i
COMMONWEALTH OF PENNSYLVANIA
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COUNTY OF ALLEGHENY
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i The Manager, Regulatory Affairs, Eugene F. Kurtz, Jr., being first duly sworn, deposes, and says:
that he is the Manager, Regulatory Affairs, Nuclear Construction Division, of Duquesne Light Company; with legal author-f ity to sign of ficial correspondence on behalf of the Vice President - Nuclear Construction Division, Earl J. Woolever, in relation to licensing for Beaver 4
Valley Power Station, Unit 2 and therefore authorized to submit the foregoing l
on behalf of the applicant.
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Date Manage r,4egulatory A f f airs l
i Sworn and subscribed before me, this
/2r'(day of 99f./ e b
, 1985.
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Notary Public ANITA ELAINE REITER, NOTARY PUBUC ROBINSON TOWNSHIP, ALLEGHENY COUNTY l
l MY COMMISSION EXPIRES OCTOBER 20,1986 4
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BVPS-2 FSAR NRC Letter: February 9, 1984 Question 210.34 (Section 3.9.3)
The staff review of FSAR Section 3.98.3.4 and 3.9N.3.4 finds that there is insufficient information regarding the design of component supports.
Per SRP Section 3.9.3, our review includes an assessment of design and structural integrity of the supports.
The review
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addresses three types of supports:
(1) plate and shell, (2) linear, and (3) component standard types.
For each of the above three types of supports, provide the following information (as applicable) for our review.
(a) Describe (for typical support details) which part of the support is designed and constructed as component supports and which part is designed and constructed as building steel (NF vs. AISC jurisdictional boundaries).
(b) Provide the complete basis used for the design and construction of both the component support and the building steel up to the building structure.-
Include the applicable codes and standards used in the design, procurement, installation, examination, and inspection.
(c) Provide the loads, load combinations, and stress limits used for the component support up to the building structure.
4 (d) Provide the deformation limits used for the component support.
(e) Describe the buckling criteria used for the design of component support.
Response
j The BVPC-2 is a non-ASME III, NF plant when addressing design and construction of component supports.
A very small percentage of j
components have supports designed and constructed to ASME III, NF i
requirements, but this is due to the purchase order date for the components. The vast majority of component supports are not designed to ASME III, NF requirements and are not required to be.
i The specific responses to the questions are provided in three separate parts.
Part 1 addresses Westinghouse supplied component supports, Part 2 addresses SWEC designed / supplied component supports, and Part 3 addresses piping component supports.
Part I - Westinghouse Supplied Component Supports Westinghouse has supplied supports only for those Class 2 and 3 components also supplied by Westinghouse to which the supports are j
attached. This equipment is divided into two groups.
Amendment 7 Q210.34-1 July 1984 l
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BVPS-2 FSAR The first group consists of auxiliary tanks and heat exchangers. The supports for these components are of two types; linear and, for the most part, plate and shell type supports. The supports for the tanks and heat exchangers meet either the requirements of Subsection NF of the ASME Code or the requirements of the AISC Code depending on the procurement date of the component. Components procured prior to the inclusion of Subsection NF into the ASME Code were designed to the AISC Code requirements. A listing of the tanks and heat exchangers and the codes to wifich the respective supports were designed is identified in the AS!!E Code Baseline Document (FSAR Table 1.7-3).
l The second group consists of Class 2 and 3 auxiliary pumps. The supports for these pumps are plate and shell and, for the most part, linear-type supports.
The auxiliary pump supports are designed by the pump manufacturer to pressure boundary stress limits, with the exception of the boric acid transfer pumps, the supports for which are designed to the limits of the AISC Code.
A listing of the Class 2 and 3 auxiliary pumps and the ASME III Code edition / addenda to which they were purchssed is identified in the AS!!E Code Baseline Document (Table 1.7-3 of FSAR).
Welding of component supports for Class 2 and 3 auxiliary equipment supplied by Westinghouse was governed by ASME IX for ASME supports, and by ASW D1.1 for supports designed to the AISC Code.
The loads and loading combinations of the supports for the auxiliary equipment supplied by Westinghouse are the same as those of the supported component. These loads and combinations are given in FSAR Table 3.9N-4.
For supports of Class 2 and 3 tanks and heat exchangers designed to the AISC Code, permanent deformation is prevented through use of the elastic stress limits of that Code.
Supports designed to the ASME Code, however, are permitted to exceed the elastic limit for faulted condition loadings.
This would result, theoretically, in a certain amount of permanent deformation.
In any case, all auxiliary tanks and heat exchangers and their supports are nonoperating passive components.
Passive components perform no safety function other than retaining structural integrity. Therefore, since only the structural integrity of the pressure boundary is required to be assured, there are no deformation limits specified for the supports for Westinghouse supplied Class 2 and 3 tanks and heat exchangers.
Deformation of supports for active pumps is limited so that certain critical clearances are maintained and the pumps remain operable.
These critical clearances are specified in the pump specifications.
Buckling is prevented by limiting compressive stresses for linear-type auxiliary equipment supports under loadings from all service conditions to the limits of AISC Section 1.5 or AS!!E Appendix XVII-2210. These limits, which are identical, are based on the Column Research Council (CRC) buckling curve for centrally loaded Amendment 9 Q210.34-2 December 1984
BVPS-2 FSAR columns. A variable factor of safety, based on column length and section material properties, provides adequate margin to the critical buckling values of the CRC curve.
A discussion of the buckling criteria for plate and shell type supports is as follows.
Buckling Criteria for Plate and Shell Type supports Plate and shell type supports for Class 2 and 3 auxiliary equipment are evaluated for buckling and instability through selective use of the criteria of Appendix XVII, Subarticle XVII-2200 and Subsection NC, Subparagraph NC-3133.6 of Section III of ASME Code.
Subparagraph NC-3133.6 gives methods for calculating the maximum allowable compressive stress in cylindrical shells subjected to axial loading that produce longitudinal compression stresses in the shell.
Subarticle XVII-2200 gives requirements for structural steel members including allowable compressive loads based on slenderness ratios and interaction equations for combined stresses.
Use of the above requirements, in addition to those of Subsection NF, in the design of plate and shell type supports for Westinghouse supplied auxiliary equipment, ensures the dimensional stability of the support throughout the range of applied loadings.
In accordance with the request of the HEB staff, a discussion on how allowable buckling stresses are calculated for linear-type supports are included in this response.
In addition, FSAR Section 3.9N.3.4, Component Supports, has been revised to reflect the discussion on Class 2 and 3 auxiliary equipment support types and design criteria.
Component Supports (Section 3.9N.3.4)
Westinghouse has supplied supports only for those Class 2 and 3 components also suppliedshy Westinghouse to which the supports are attached. The loads and loading combinations of the supports are the same as those of the supported component.
These loads and combinations are given in FSAR Talbe 3.9N-4.
e The Class 2 and 3 auxiliary equipment supplied by Westinghouse is grouped into two general categories. One group consists of tanks and heat exchangers.
The other group is auxiliary pumps.
Design criteria for the supports for these components are discussed below.
Tanks and Heat Exchangers (Section 3.9N.3.4.1)
The supports for auxiliary tanks and heat exchangers are of two types: linear and, for the most part, plate and shell type supports.
The supports meet either the requirements of Subsection NF of the ASME Code or the requirements of the AISC code, depending on the procurement date of the component.
Components procured prior to the inclusion of Subsection NF into the ASME Code were designed to the Amendment 9 Q210.34-3 December 1984
BVPS-2 FSAR AISC Code requirements. A listing of the tanks and. heat exchangers and the codes to which the respective supports were designed is identified in the ASME Code Baseline Document (Table 1.7-3).
Auxiliary Pumps (Section 3.9N.3.4.2)
The supports for class 2 and 3 auxiliary pumps are plate-and-shell-type and, for the most part, linear-type supports. The supports for all Class 2 and 3 pumps supplied by Westinghouse are designed by the pump manufacturer to pressure boundary stress limits (ASME III, Subsection NC/ND, as applicable), with the exception of the boric acid transfer pumps, the supports for which are designed to the limits of the AISC Code. A listing of the Class 2 and 3 auxiliary pumps and the ASME III Code edition / addenda to which they were purchased is identified in the ASME Code Baseline Document (Table 1.7-3).
Part II - SWEC Supplied / Designed Component Supports (except for Pipe Supports)
(a) The SWEC Supplied Component Supports The SWEC supplied component supports are limited to supports supplied with ASME III, Class 2 and 3 components.
ASME III components designed and constructed to the ASME III Code, 1971 Edition through Summer 1973 Addenda or earlier have supports-designed and constructed to the AISC Code. ASME III components designed and constructed to the ASME III Code, Winter 1973 Addenda or later have supports designed and constructed to ASME III, NF requirements. A listing of the ASME III components with supports and the applicable codes to which the respective supports are designed is identified in the ASME Code Baseline Document (Table 1.7-3).
.The load and load combinations of the SWEC supplied components supports are the same as those of the supported components.
These loads and load combinations are given in the ASME III design specifications for the components.
The stress levels reached due to combined load conditions do not exceed the maximum stress levels permitted by the applicable code.
All equipment supports are designed to elastic limits.
Deformation limits are not used.
AISC jurisdiction is assigned to embedments or building steel to which the supports are attached. The anchorage design criteria is described in the response provided for Question 210.35.
(b) SWEC Designed Component Supports The SWEC designed component supports are those intermediate structures which connect the ASME III component to the building
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Amendment 9 Q210.34-4 December 1984 J
BVPS-2 FSAR structure.
The jurisdictional boundary is the embedment or building steel to which the supports are attached.
Bolted connections at the jurisdictional boundary are described in the response to Question 210.35. Welded connections were not used at the structural interface except for the RHR cooler restraint which has a welded connection within the jurisdiction of the component support.
The SWEC designed component supports for ASME III equipment are designed using ASME III NF as guidance. The basis for the design and construction of the supports for the ASME III, Class 1 primary equipment is provided in the response to Question 210.43.
For ASME III Class 2 and 3 equipment supports, the design basis is provided in the Table 3.9B-16.
The loads, load combinations, and stress limits for the ASME III, Class 1 primary equipment supports are identified in Table 5.4-21 and for the ASME III,. Class 2 and 3 equipment supports in Table 3.9B-16.
All equipment supports are within elastic limits as stated in Tables 5.4-21 and 3.9B-16.
Deformation limits for supports are not used.
The buckling criteria for the equipment supports are in accordance with the AISC code.
AISC jurisdiction is assigned to the embedments or building steel to which the supports are attached.
The anchorage design is described in the response provided for Question 210.35.
Part III - Piping Component Supports Except for integral welded attachments defined in Section 3.9B.3.4.2, pipe supports are not designed or constructed to ASME III requirements because their design and procurement proceeded ASME III, NF.
Therefore, plate and shell type designations are not applicable.
The response to items (a) through (e) of Question 210.34, as applicable to pipe supports, are (1) All pipe supports are designed as described in Tables 3.9B-14 and 3.9B-15, Amendment 7.
AISC jurisdiction is assigned to embedments or building steel to which the pipe supports are attached.
(2) Pipe supports meet the criteria of the AISC code ANSI B31.1 l
Code and Tables 3.98-14 and 3.9B-15.
When pipe supports include integral attachments to pressure retaining boundaries, the integral welded attachments are designed, fabricated, installed, and inspected in accordance with the criteria stated in Section 3.9B.3.4.2.1.
O Amendment 9 Q210.34-5 December 1984
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(3) Loads and load combinations used to design pipe supports are described in Tables 3.9B-14 and 3.9B-15, Amendment 7.
The allowables are based on the AISC Code. The loads, load combinations and the corresponding allowables for designing integral attachments to the pressure boundary are described in Section 3.98.3.4.2.1.
4 (4) All pipe supports are designed to elastic limits.
Deformation limits are not used.
(5)' Buckling criteria for pipe supports are in accordance with the AISC Code.
$5fTJh&
Summary Component supports for BVPS-2 are not designed or constructed to ASME III, NF requirements for the majority of components.- SWEC will specifically identify supports designed and. constructed to NF
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requirements in the ASME Code Baseline Document (Table 1.7-3).
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Amendment 9 Q210.34-6 December 1984 4
,D INSERT A As indicated in Table 3.98-14, thermal ef fects in the piping are included in l
the Normal / Upset condition load combinations for wh ich stresses are not permitted to exceed
~.8 Sy.
Since the Normat/ Upset loads (including thermal e f fects) do not cause inelas tic -- de format ion in pipe s uppo rt s, the ductile
-. characteristics of the support material and the self-equilibrating character-istics of any additional thermal ef fects and seismic anchor motion associated with the. Faulted condition assure that deformations remain' acceptably small.
As ve rification that pipe and eq uipment supports are inherently capable of withstanding the effects of full SSE anchor motion, a sample review of certain critical systems has _ been performed.
The details of this sample review are contained.in Attachment Q210.34-A.
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4 ATTACHMENT Q210.34-A
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Introduction:==
An investigation has been performed to demonstrate that pipe and equipment supports are inherently designed for the effects of SSE anchor motion.
Results:
Though we do not concur with the above being a requirement of our licens-ing basis, the following has been undertaken in response.
In order to demonstrate pipe and equipment supports inherent capability to j
withstand ef fects of full SSE anchor action, 100% of the large bore pipe s uppo rt s for the emergency core cooling system were selected as a sample basis.
This system includes a s ubs t ant ial number of large bore piping support s and is representative of the piping and equipment most critical to plant safety. All ECCS pipe supports in the safety injection and recir-culation spray piping include SSE anchor action effects and are designed against 0.95 Sy in accordance with FSAR Table 3.9B-15.
The remaining ECCS piping contains 70 large bore supports which were not originally designed to include SSE anchor motion.
These have been evaluated to include the ef fect of SSE anchor motion. The resulting stresses were compared to 0.95 i
Sy, and were found to be acceptable in all cases.
An additional 91 large bore supports were select ed from various safety related systems to establish the capability of pipe supports to withstand the ef fects of SSE anchor motion on piping between buildings.
When stresses were calculated for design loads which include SSE anchor motion and compared to 0.95 Sy, all supports were found to be acceptable.
The equipment supports sample included the following equipment from ECCS:
4 recirculation spray cooler support
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recirculation spray pump support The following additional equipment supports were included:
neutron shield tank cooler support degasifier recovery heat exchanger support degasifier steam heater support i
For the equipment support s above, a comparison was made of support s trai ns for the normal / upset and faulted conditions including the ef fects of 1/2 SSE ancho r act ion - and SSE anchor ac t ion, respectively.
Results ranged f rom a 10-20 percent increase in strain; however, stress values remained well below yield.
The above component supports are SWEC supplied supports and they were used in the sample study in order to utilize detailed calculations.that we re readily available to the architect engineer. However,.several Westinghouse j
supplied component supports, the RHR ptap support, and the RHR heat exchanger support were reviewed by the architect engineer and the results show a similar pe rcent change in strain and stresses below yiel d.
The component support s included in this sample study are repres ent at ive of those most critical to plant safety, s
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