ML18052A969

From kanterella
Jump to navigation Jump to search
Rev O to Response to Palisades Integrated Plant SAR Open Items,Palisades Nuclear Plant.
ML18052A969
Person / Time
Site: Palisades Entergy icon.png
Issue date: 04/30/1987
From:
EQE, INC.
To:
Shared Package
ML18052A966 List:
References
87137.01--1, 87137.01--1-R, 87137.01-0-001, 87137.01-0-001-R00, NUDOCS 8705040208
Download: ML18052A969 (31)
v • d • e


Text

ATTACHMENT E Consumers Power Company Palisades ~lant Docket 50-255 EQE REPORT ON MOTOR CONTROL CENTERS 1 AND 2; CONTROL PANEL c~33; AND SWITCHGEAR CABINET lD AprH 30,'1987 l

. *- -:-~~.\---".. ...,,,

  • _.'-- -~~-~2.0:a:-moir;~5s *_. \\* \

( -

  • 9705~~0c~-.-o50._, ..p1)R;:..

, pDR *. *.. * ... * * ,.

P' * ' 30 Pages

  • ATT0487-0048-NL04

~87137.01-0-001 Rev1s1on 0

. Page 1 of 30 RESPONSE TO PALISADES IPSAR OPEN ITEMS PALISADES NUCLEAR PLANT Apr11 1987 Prepared for:

Consumers Power Company 212 West Michigan Ave Jackson, Michigan 49201 EQE Project. Number 87137.01

...... ...* ~, ....... , --~..... *- .,...,._ ... ' .... -.:.. *.;;;;;,:;.. ..... ~- *-*-* -~---.......--~~~... ,c;-.. .*-* . - - .-_,, "".::. .. --,~*--'I-' fl---.-~ ...-.... :..."'<:; - ... ::_~~i:..;;...,:_-~,.., --~ :... * - . ... ~ " ~.;.-.. --~-

j e 87137. 01-0-001 Rev1s1on o Page 2 of 30 This Page Intentionally Blank

87137.01-0*001 Rav1s1on 0 Page 3 of 30

  • RESPONSE TO PALISADES JPSAR OPEN ITEMS Technical Report No. 87137.01-0-001 I

Revision O I

Date: April 30, 1987 t

I

.87137.01-0-00I Rav1s1 on O Page 4 of 30

-i TABLE OF REVISIONS Revision o*

date: April 30, 1987

. Orf g1nal Issue

e e 87137. 01-0-001 Revision O Page 5 of 30 ABSTRACT This report documents the se1sm1c review of control cabinet C-33, motor control centers MCCl and MCC2 and switchgear 10 tn the Palisades Nuclear Plant. The report describes the purpose of the se1sm1c verification, the experience database methods and analytical methods used to ver1fy the se1smic adequacy, and presents the conclusions and recommendations to ensure Plant. seismic adequacy of the specific cabinets at Palisades Nuclear

    • i
  • ~.

87137. 01-0-001 Rev1s1on O Page 6 of 30 TABLE OF CONTENTS Page Title Page 1 Conf1dant1a11ty Statement 2 Approval Cover Sheet 3 Table of Revisions 4 Abstract* 5

. Table of Contents 6 1.0 Purpose 7 2.0 Descr1pt1on of Specific Components/Items Covered 7 3.0 Methodology Used and Basis 8 4.0 Summary of Results 23 5.0 Conclusions 25 6.0 References 28 Figure 1 30

  • p -

e ~87137.01-0~001

  • Revh1on o  ;

Page 7 of 30

. RESPONSE TO PALISADES IPSAR OPEN ITEMS

l. 0 . PURPOSE The purpose of this. report 1s to address the following specific open items from USNRC Letter to Consumers Power Co, dated
  • September 6, 1983. These open 1tems are the following.
  • 1.1 CONTROL PANEL C*33 USNRC Item IV D - *s1nc1 the structure (shape, structural framing, anchorage system, etc.) of control panel C*33 1s different from MCCl and MCC2, justification is needed for qualifying C-33 based on the evaluation result of MCCl and 2." .

. 1. 2 SWITCHGEAR 10 USNRC Item IV C * *No evaluation result for switchgear ID were submitted for review.*

1.3 MCCl and MCC2 USNRC Item IV a* *The 0.2g aceelerat1on (zero period.

acceleration of the horizontal ground response spectrum) .

used as the vertical component of se1sm1c 1nput for the MCCl

  • and 2 internal device anchorage is too low. The licensee should calculate the natural frequencies for the internal device-anchorage system first and the obtain the spectra1
  • aece1eration from the corresponding floor response spectra*

for* eva1uat1on. The same concern is also applicable to the

. load path evaluation of MCCl and 2 and to any electrical equipment which were evaluated using the same approach for MCCl and Z."

1.4 Amplificat;on Due to Out-of-Plane Vibration o.f _Floors.

USNRC Item II B - "The licensee s analysis ~id not consider 1

possible additional amplification of the in-structure response spectra (input to the subsjstem evaluation) due to out-of-plane vibration of the floors.*

2.0 Descr1pt~on of Specific Components/Items Covered The following cabinets are covered *n this evaluation:

- Switchgear 10

- Control Panel C-33

- MCCl and HCC2

I L

87137.01-0*001 Revision 0 Page B of 30 The items covered for each cabinet 1n thts evaluation are the_

fol 1ow1 ng: * ** *

  • Cabinet structure
  • .Cabinet anchorages
  • Devtce supports Se1sm1c adequacy of the devic:eswas not included in.the scope of th1s work effort.
  • 3.0. Methodology Used and Basis
  • The basis of se1sm1c qua11f1eat1on ts the app11eat1on of experience data. This has been done in accordance wtth the methods described 1n USNRC generic letter 87*02, Reference 1.

This qua11f1cat1on by seismic experience data has been supplemented by a review of available URS Blume calculations* to evaluate the conservatisms used and margins available. *.

3.1. Seismic Expe1"1.ence Data.Method in Accordance wtth Generic letter 87*02 The methodology applied 1s 1n accordance wtth that des~r1bed 1n USNRC Generic Letter 87-02.

Detailed methods used are 1n accordance w1th the Senior Se1sm1c Review and Advisory Panel (SSRAP) report, Reference 4. This report extends the experience data base as discussed 1n Section 7 {page

. 19) of Generic Letter 87-02 *

. Anchorages have been evaluated using the URS B1ume/EPRI *seismic Anchorage Guidelines for Nuclear Plant Equipment", Reference S.

An on-site walkthrough of all components was performed by EQE engineers with CPCO support. During this on-site review, all equipment was reviewed, photographs taken and relevant information for qual1f1cation was recorded.

  • Items which cannot be qualified by.use of the experience data base
  • criteria are considere*d "outliers". Outliers are qualified either by further review of the data base or by analysis.
3. 1 . 1 Spec tr.a Comparison

e e 87137.01-0-001 Revtsion 0 Page 9 of 30 In Figure 1 the SSRAP Bounding Spectrum (Reference 4) is shown compared to the*NUREG/CR 1833 response spectrum (.2g Reg Guida hor1zonta1 ground motion site response spectrum).

In accordance with the SSRAP requirements, the free field spectra for 51 equipment damping are compared. A further requirement that this comparison 1s valid only to equipment located below 40 feet above grade 1s also met, as shown below.

EQUIPMENT ELEVATION lliI AB()jE WD1 SWGR ID 607 1 &* 17 1 6*

C-33 590 1 0* 0'0" MCCll2 607 1 &* 17 1 &*

3.1.2 Walkthrough Inspection And Experience Data Review A walkthrough inspection was. performed for control cab1net.C*33, motor control centers One and Two, and switchgear issembly 10.

The purpose of the walkthrough inspection was to determine the in*

situ seismic charaeter1st1cs of the cabinets' structure, the anchorage of the cabinets, and the inchorage of the devices within the cabinets. This determination focused on: ,

a) Judgmental evaluation of any factors which might affect the se1sm1c performance of the equipment~

b) A review of any unusual or non-typical conditions such as major modifications to standard equipment or equipment that 1s unique.

c) Assessment of the adequacy of equipment anchorage.

The walkthrough was performed by two enginee~s who have knowledge of the_ failure modes and performance during strong earthquakes -of components in heavy industrial process plants and fossil fuel power plants and also have knowledge of nuclear design standards and seismic design practices for nuclear power plants. Therefore, these two engineers (one civil/structural and ~ne mechanical engineer) had the ability to perform seismic capability evaluations including structural/mechanical analysis as needed.

  • control Cabinet C-33 Control cabinet C-33 is located at £levat1on S90'o* of the Auxiliary Building of the Palisades plant, one level below grade.

This location of the cabinet allows a comparison of the Palisades horizontal *site spectrum with the horizontal ground motion bounding spectrum -(Reference 4). This comparison, as indicated in

~7137.01*0*001 Revision O Page 10 of 30 section 3.1.1, determines that the contro1 panel 1s w1th1n the se 1sm1 c mot 1on bo*unds of the exper1 ence data. * *

  • Within the experience data, contro1 panels are represented by the generic classification of Control And Instrumentation Panels. The Senior Seismic Review and Advisory Panel (SSRAP) has established a set of restrictions for thfs generic equipment class1f1cat1on, based on sources of *seismic damage (or malfunction) in past .

earthquakes. These restr1ct1~ns for control cabinet C*33 ara reviewed below:

The stee1 frame and sheet meta 1 were eva 1ua ted for adequacy.

  • The structure of panel C-33 is typical of normal industrial
  • construction and instrumentation panels found at data oase sites. The structural details of the panel comply (and in fact exceed) industrial standards such as publication UL~ .

508, R Industrial Control Equipment*, by Underwriters .

  • Laboratory:(Raf.13). *
  • The unit must be properly anchored. The anchorage was determined to be as specified 1n Reference 6. The seismic adequacy of the anchorage was subsequently evaluated in accordance with the guidelines specified 1n Reference 5 and found to be adequate. *
  • There should be sufficient slack and flexibility in connections. such as electrical cables. to the control and instrumentation panels. The electrical attachments to panel C-33 are through the top of the cabinet to cable trays and .

conduits routed above. These attachments were inspected and f'ound to have adequate flexibility to ac~onrnodate the very minor degree of flexure that would be expected for this

  • well-anchored unit.
  • Units should be properly anchored to adjacent units to avoid seismic induced impacts. *On inspection it was seen that .*

control cabinets C-33 and one of the adjacent cabinets, C-40, are not attached. If is therefore required that control unit C-33 and C-40 be attached either by bolts through the

  • side walls of the cabinets at appropriate places or via a mod1ficat1on at the* roof of control units C-33 and C*40.

The general configuration of devices located w~th1n control unit C-33 was reviewed and found to be sim;lar to the configurations repres~nted within the experience data. No unusual or non-typical conditions were found.

  • The SSRAP reconwnendations (Ref .4) for an* inspection for possible seismic interaction hazards (such as unsecured overhead fixtures) in the vicinity of the equipment were not addressed in the walkthrough. This stipulation ~as not

____________................................... ~

87137.01*0-001 Revision o

. Page 11 of 30 considered part of the current Systematic Eva1uat1on Program

. (SEP) structural eva1uat1on of Panel C-33.

The generic expertence data class1ficat1on designated as ~ontro1 and instrumentation panels includes all instrumentat1on and* .*

control devices mounted 1n sheet metal cabinets (control panels).

Typical devices normally mounted 1n sheet metal Cib1nets include .

those mounted in unit C-33: *

  • controllers recorders switches pushbuttons pane1 lights 1nstrwnent transformers The mounting of the devices 1n unit C-33 WiS reviewed. The mounting configurations were determined to be fn accordance with standard industrial practices. The device mounting conf1gurat1ons were determined to be represented by components within the *.

experience data and are considered seismically adequate. No instances of unique mounting configurations or m1ss1ng attachment bolts were found. All devices. contained 1n C-33 are*adequately restrained for the postu1ated seismic event *

.Motor Contro1 Centers 1 and t Motor Control Centers 1 and 2 are located at the 607' 6" level 1n the Auxiliary Building of the plant. The location of the equipment places it low enough with respect to grade level (within 40 feet of grade) to permit a comparison of the Palisades horizontal site spectrum with the*hor1zonta1 ground motion

  • bounding spectra. This comparison, as indicated in section 3.1.l, determines that the motor control centers are within the seismic .

motion bounds of experience data.

  • Within.the experience data. a generic class1f1cat1on for motor control centers exists. Motor control centers (MCCs) primarily contain ~ircuit switching and protection devices for electric motors,. most conwnonly powered at 480 volts AC. Motor control centers are sheet metal cabinets containing motor controller enclosures inserted into shelves in the cabinet framing. Each motor controller typically contains a molded case circuit breaker or fused disconnect switch, a magnetic contactor for closing the 480 volt circuit dur;ng motor starting, and a separate.120 volt
  • ................................................-......... a

87137 .01*0*001 Revision O Page 12 of 30 CQntrol circuit served by a small 480/120 volt 1nstruinent transformer.

Shelf-mounted motor eontrollers are arranged 1n vertical stacks, or cabinet sections, that are bolted together through adjo1n1ng walls (or joined by a connon cabinet framing structure) to form the motor control center. Motor eontrollers may be mounted on the front face of the MCC only, or on both front and rear faces. A rear compartment (or center compartment on double*facad MCCs) contains vertical bus bars that supply power to the individual controllers.

  • The Senior Se1sm1c Review and Advisory Panel (SSRAP) has* .*

established a set of-restrictions for the generic equipment class

. of motor control center~ based on sources of seismic damage 1n past earthquakes. These restrictions are reviewed below:

The Cutler-Harmier motor control centers 1 and 2 have a continuous sheet metal panel which aets as a shear wa11 between each cabinet section~ In addition, the individual bays of the control centers are secured with- an adequate bolting configuration at both the front and rear of the shear pane1s. This, together with the adequate base anchorage, ensures that the multi-bay cabinets will not have a fundamental frequency low enough to be in resonance with both the fundamental frequency of the structure and the frequency of the earthquake .

. It was determined that there are no external attachments of any s1gn1ficant mass supported on the motor control centers.

There were no long unsupported conduit runs of equipment .

supported to the motor control centers. Therefore, high centers of gravity or eccentric weight induced excessive torsions are not of concern.

  • It was ascertained that the lo~er half of the cabinet sheathing does not have cutouts in excess of 6 inches wide

.and 12 inches height. Therefore, as previously stated, the motor control centers' fundamental frequency is not 1n ..

resonance with both the fundamental frequency of the structure and the frequency content of the earthquake.

The standard design of the Cutler*Hanvner cabinets, a common supplier to the power industry, complies with (or exceeds)

NEMA standards. * *

  • The anchorage of. the motor control units was detennined to be as specified in Reference 7*. The seismic adequacy of the.

anchorage was subsequently evaluated in accordance with the guidelines spec1f1ed in Reference 5 and found to be adequate.

e ~ 87137.01-0-001 Revision 0

  • Page 13 of 30 The general configurat1on of devices loc*ted within motor .

control centers I and 2 was reviewed and found to be similar to the conf1gurat1ons represented within the experience data. No unusual or non-typical cond1t1ons were found.

The SSRAP reco11111endat1ons (~ef .4) for an 1nspeet1on for possible seismic interaction hazards (such as unsecured overhead fixtures) 1n the v1c1n1ty of the equipment were not addressed 1n the wa1kthrough. This stipulation was not considered part of the current Systematic Evaluation Program

  • (SEP) structural evaluation.* * * .* * . .

The devices included 1n the Palisades motor control units are*

contactors, control transformers, re1ays, disconnect switches, reset switches, and termina1 blocks. The mounting configurations of these devices were reviewed and 1t was determined that the mounting configurations of HCC 1 and 2 devices are represented by mounting configurations of equipment within the experience data.

During the walkthrough, it was determined that the mounting ..

configuration of all devices, except a number of transformers, were in conformance with standard industrial practice and are considered se1smical1y adequate. A number of transformers in the motor contro1 units had only three of four mounting bolts

  • installed. As descr1bed in section 3.1.3.d, this unique .

configuration was reviewed 1n detail and determined to be .

  • se1smica11y adequate. All devices contained 1n motor control
  • centers 1 and 2 are adequately restrained for the postulated seismic event.

Switchgear _Assembly l*D Switchgear Assembly 1-D is located at 607'6' in the Auxiliary .

Building of the Palisades plant, adjacent to the room containing motor contro1 centers 1 and 2. As with the MCCs, the location of the equipment places it low enough with respect to grade level (within 40 feet of grade) to permit a comparison of the Palisades horizontal site spectrum with the horizontal ground motion bounding spectrum, This comparison, as indicated *1n Section

  • 3.1.1, determines that the switchgear assembly 1-0 is within the seismic motion bounds of experience data.

W1th1n the exp.er1ence data, a generic classification for med.ium voltage switchgear a~semb11es exists. The medium voltage_

switchgear assemblies consist of rows of abutting sheet metal cabinets containing roll-in circuit breakers for the protection of large electric motors of medium voltage circuits 1n the range of 600 to 6000 volts. The switchgear assemblies include the primary circuit* breakers in a forward compartment, bus bar compartments for power supp1y to the rear of the ci rcu 1t breakers, and small .

instrumentation and relaying equipm~nt, served by separate low voltage AC or DC circuits, mounted on the front or upper compartments of the cabinets. *

  • 87137 .01*0*001 Revision O Page 14 of 30 The Senior Sahmic Review and Advhor,y Pane1 (SSRAP) has established a set of requirements for the equipment category of medium voltage switchgear, based on sources of seismic damage in*

. past earthquakes. These requirements, as they apply to the Palisades sw1tehgear assembly 1-0 are reviewed below:

  • The cabinet construction of switchgear assemblies must be generally similar to American National Standard ANSI C37.20.

Switchgear assembly 1-D was observed to represent normal industrial practices for medium voltage switchgear, wh1eh is 1n compliance with this standard. - ..

The- switchgear assembly 1-0 has a shear panel betW&en e*ch cabinet section and adjacent sections of the multi-bay cabinet assemblies are bolted together. These cr1ter1a,*

together with adequate base anchorage, assure that the switchgear assembly 1-0 w111 not have a fundamental frequency below 8 Hz. and will not be in resonance with both the frequency content of the earthquake and the fundamenta1 frequency of the structure.

The cabinet sheathing (1nclud1ng 1nterna1 shear panels) of switchgear assembly 1-D did not have panel cutouts in width excess of 3°' of the width of the side panel or 1n height excess of 60I of the width of the side panel. Therefore the cabinet can be considered of adequate stiffness including cutouts.

The unit must be properly anchored.- The anchorage was determined to be as specified in Reference 8. The seismic

. adequacy of the anchorage was subsequently evaluated using conservative calculations {see section 3.1.3.c) and found to be adequate. *

  • The genera1 configuration of devices located within switchgear assembly 1-D was reviewed and found to_be similar
  • to the configurations represented within the experience data. No unusual or non-typical conditions were found.

The SSRAP recommendations (Ref .4) for an inspection for possib1e seismic interactions hazards {such as unsecured overhead fixtures} in the vicinity of the equipment were not considered part of the current Systematic Evaluation Program (SEP) structural evaluation of switchgear assembly 1-D.

The devices in the Palisades sw~tchgear assembly 1-0 include the

  • primary circu.it breakers, bus bar compartments in the rear,

. breaker switches, control transformers, relays and trip switches.

Th~ mounting conf1gtirat1ons of these devices were reviewed and it was determined that the mounting configurations of the switchgear assembly 1-0 devices are represented by mounting configurations of

87137.01-0*001

\ Rav1s1on O

' . Page 15 of 30 equipment w1th1n the experience data. During the walkthrough, 1t was determined that the mounting conftgur1t1ons were 1n conformance w1th standard 1ndustr1a1 practice and are considered se1sm1ca11y adequate. All devices contained in switchgear assembly l*D are adequately restrained for the postulated seismic event.

  • 3 .1*~3 Determt ne Anchorage Adequacy
a. Control Cabinet C-33 The 3/4* d1a. expansion anchor bolts were evaluated 1n accordance wtth Reference 5. (Section 15 - *Development and Use of Anchorage Guidelines for Generic Equipment Cabinets*). As reeonmended by SSRAP, a seismic loading of 1.5 times the Bounding Spectrum was applied to the cabinet.

The result of this evaluation showed a large margin of safety for the expansion anchor bolts. Seismic demand

  • l.2g and se1sm1c capacity 1n excess of 4.lg.
b. HCCl and MCC2 The 1* dta. expansion bolts were evaluated 1n accordance with Reference 5 (Section 8 - *oeve1opments and Use of Anchorage Gu1de11nes for Motor Control Centers*). As
  • reeo11111ended by SSRAP, a sehm1 c loading of 1. 5 times the Bounding Spectrum was applied to the MCCs. The result of this _evaluation showed a large margin of safety for the expansion anchor bolts. Seismic demand* l.2g and seismic capacity in excess of 3.Sg.
c.
  • Swttchgear 10 As Reference 5 does not have av an able criteria for Med tum Voltage Switchgear, it was necessary to perform qualification of the Switchgear 10 anchorage using conservative hand calculations. Conservative NUREG/CR~l833 spectral values of l.4g horizontal and 1.4g vertical were applied to the switchgear (Section 3.2.2.b). The result of
  • this evaluation is that the l/2w dia. expansion bolts at the end of the cabinet have a load of 1190 lb/ bolt, and a capacity of 1200 lb/ bolt. It should be noted that this calculation is quite conservative and in excess of SSRAP reconrnendat1ons.
  • d..
  • Device Anchorage Outliers Only one device anchorage outlier was identified. This occurred in MCCl and MCC2. No device anchorage outliers occurred in the cabinet C-33 or in the Switchgear 10.

~ 87137.01-0-001

  • Revision O Page 16 of 30 In the MCCs a number of transformers, which are des1gned for four (4) bolts, were -1nstal1ed w1th<only three (3) of the
  • bo1ts. this outlier had also been ~oted by CPCo and URS Blume 1n previous walkdowns.

A simple, conservative hand calculation was performed for th1s out11er. The conservative assumptions used by URS Blume .

for dev1ee anchorage qua11f1cat1on (see section 3.2.2.b) were appl1ed in th1s evaluation. The SSRAP recommended sa1sm1c: 1oading of 1.5 times the Bounding Spectrum was applied to the base of the cabinets. The resu1t of this.

evaluation showed 1 large margin of safety for the 3 bolt transformer anchorage (see Section 3.2.2.c~3). Seismic demand at the HCC floor level 1s l.2g and the seismic.

capac 1ty at the floor 1s 1. 69. *

  • As descr1bed 1n Section 3-.1.2, the device mounting configurations control cabinet C-33,-MCCl and MCC2, and switcngear 1-D were determined to be represented by mounting conf1gurat1ons of equipment in the experience data .. Except for the outliers addressed above, a11 of the devices are mounted in conformance with standard industrial practices
  • and .are ~onsidere~ to be seismically adequate based on.

experience dati.

3.2 Review of Existing Ca1cu.lat1ons and Anchorage Modifications Previously Done To supplement the qualification* by seismic experienc:e data, a review of all available URS Blume ca1culat1ons was performed to determine the adequacy of anchorages and structures. The anchorage calculations (References 6, 7 and 8} and subsequent anchorage modff1cat1ons 1nsta11ed were performed in response to l&E Information Notice 80-21.

3.2.1 Ava1lab1e Calculations URS 81 ume analyses for the f o11 owing 1terns were rev.i ewed:

a*. Control Cabinet C-33 Anchorage Reference 6

b. HCCl and MCC2 Anchorage Reference 7
c. SWGR ID Anchorage Reference 8
d. MCCl and MCC2 Cabinet Structural

.Integrity

  • Reference 9 *
e. MCCl and HCC2 Oev1ce Anchorage Reference 10

e 87137 .01.0.001 Revision 0 Page 17 of 30.

3.2.2 E~1st1ng Calculation Basis and Results

a. Applicable Floor Response Spectra The URS Blume calculations were performed using the or1g1na1 design response spectra for Palisades

{Reference 11). In this review. all calculations were mod1f1ed to account for the application of NUREG/CR 1833 floor response spectra, Reference 2. The

  • comparison of spectral values used is su111narized below. A11 values* are for SI damping.

As can be seen frOrR this table, this review was performed with slightly lower horizontal accelerations

{NUREG vs Blume), and substantially higher vert1cal accelerations.

b. Analytical Methods Applied
1. Anchorage Analyses (al 1 cabinets)

Loadtng applied for analysis of the cabinet anchorage

  • 1s earthquake plus dead load. Earthquake loading is based on NUREG/CR-1833 loadings. The application of these loadings 1s as described below. Two load cases were considered:
  • Vert1ca1 Se1sm1c + Longitudinal Seismic + OL Vertical Seismic + Lateral Seismic + DL Acceptance criteria applied is based on the following:

USNRC Standard Review Plan (SRP) 3.8.4, which

~tates that allowable limits for st~el are to be

  • 9 87137 .01-0-001 Revision o Page 18 of 30 l.& times the allowable stresses for elastic
  • design defined in Part 1 of AISC, Feb 12, 1969.

Gu1de11nes of the evaluation and des1gn of

/ expansion anchors and base plates were taken from Reference 14, which is based on work perfonned at Pa H sades Pl ant 1n response to USNRC IlE Bulletin 79*02 and its revisions.

Reference 14 was used for existing expansion anchors and new expansion anchors installed with a minimum embedment. Designs ut111z1ng embedment 1n excess of the m1n1mum were based on allowable values of the International Conference of Building Officials (lCBO) Report 2156, Kw1k~Bolt and Super.Kw1k-Bo1t Concrete Anchors.

URS Blume anchorage analyses were performed using conservative hand calculations. URS Blume checked the following anchorage items for each cabinet:

- Expansion anchor bolts

- Anchorage structure (channels, plates, etc)

- Bolted connections

  • Welded connections The review of the calculations was performed as follows:

Review existing calculations to determine completeness.

  • Mod1ftcat1on of calculat1ons to account for differences between NUREG/CR 1833 in-structure response spectra* and those used by URS Blume for -*

their calculations. .

  • Su111nar1ze of results for most .limiting structural component. This indicates the minimum margin availab1e, based on analysis using. *
2. Cabinet S~ructural Integrity (HCCl and MCC2)

URS Blume cabinet structural integrity analyses were performed us1ng conservative hand.

calculations. URS Blume checked the following 1tems and loadings.

~- 87137.01*0-001 Revision O*

  • Page 19 of 30 Load1n9s:

Combined transverse plus vertical loadings for each 1tem

  • Combined 1ong1tud1nal plus vertical for
  • each item Acceptance criteria applied are as follows:

A36 steel is assumed as the material of the cabinet.

USNRC Standard Review Plan (SRP) 3.8.4. which states that allowable limits for steel are to be l.& times the allowable stresses for elastic design defined in Part 1 of AISC or AISI~

Items analyzed:

  • Cabinet lags

- Anchor edge plates

- Supporting channels .

  • Module anchorage to vertical channels
  • Vertical channels to MCC s1da wall
  • Side walls To account for higher modes of cabinet vibration. the peak spectral values in the table above were increased by a factor of 1.5.

The review of the MCC cabinet structural analyses were performed 1n the same manner as described above for anchorage reviews.

3. Device Anchorages (HCCl and MCC2) loading applied for analysis of the device anchorages is earthquake plus dead load of the device. Earthquake loading 1s based on NUREG/CR-1833 loadings. The application of these earthquake loads is as described below. Two cases are considered:

Vert1c~1 S~tsm1c + long1tud1na1 Seismic + nL Vertical Seismic + Lateral Seismic + DL Acceptance criteria applied is based on the

  • allowable stresses for the device anchor bolts.

Properties used were for A307 bolts. Bolt allowable stresses were calculated in accordance

.e 87137 .Ol-0*001 Rev1S1an O Page 20 of 30.

~.

with AISC (8th Ed1t1on) cr1ierh for shear and i' .

. - tensile stresses. In accordance with USNRC t Standard Rav1ew Plan 3.8.4, the allowable i*

  • stresses were 1ncraased by 60I.

URS Bluma dev1ce anchorage analyses were

  • performed using conservative hand calculations.

Capacities of device anchor bolts were checked against the seismic demand.

In the URS Blume calculations, the following conservative assumptions are made regarding cabinet and device resonances for horizontal loading:

The cabinet is 1n resonance w1ih the floor (acting as 1 cantilever)

The device is 1n resonance with the

.cabinet (acting as a mass 1n the middle of a plate at the top of the cabtnet)

These conservative amp11ficattons are applted to the horizontal peak spectral value. This results 1n a horizontal acceleration of 21.Sg.

For the vertical response 1t is assumed that the cabinet and plate are r1gid. To account for.

twisting due to subcomponent cantilever action, the peak of the vert1c11* ground response spectrum ts used. This results in a vertical acceleration of 0.20g.

  • The review of the device anchorages was performed as follows:

Review existing calculations to determine completeness. * - -'

Modification of calculations to account for differences between NUREG/CR 1833 in-structure response spectra and those used by URS Blume for their calculations. For

  • the horizontal earthquake this results iri a decrease from 21.Sg to 16.69~ For the vertical earthquake this results in an increase from 0.209 to l.40g.

Su1T111ar1ze of the result for most limiting structural component. This indicates the minimum margin available (based on

~87137.01-0-001 Revision o Page 21 of 30 analysis) for NUREG/CR 1833 response spectra .1oads. . * *

c. Results from Review of Calculit1ons
l. Anchorage analyses
  • Control Cabinet C*33 The m1n1mum margin is in the 3/4 1 d1a.

expansion anchor bolts. The anchor bolt stress ratio to allowable is 0.87 (131 stress margin). All other margins are much larger.

  • Motor Control Centers
  • MCC1
  • MCC2 The minimum margin is in the 1* dia.

expansion anchor bolts, due to overturning.

and vertical loading. The anchor bolt .

stress ratio to allowable*1s 0.91 (20I *

  • stress margin).
  • Switchgear 1~

The m1n1mum margin 1s 1n the 112* d1a.

  • expansion anchor bolts, due to .

longitudinal overturning loading. The anchor bolt stress ratio to allowable is 0.99 (1% stress margin).

2. Cabinet Struc.tura1 Integr1 ty (MCCl l MCC2)

The minimum margin 1s 1n the axial loading on the cabinet legs, due to combined overturning and vertical loading. The combined axial plus bending stress tn the

. legs has a stress ration to allowable of 0.95 (SI stress marg1~). *

3. Device Anchorages (MCCl l MCC2)

All device anchor bolt stresses were conservatively qualified on a dev1ce-by-

  • devtce basis. The minimum margin occurs 1n the three (3) bolt anchorage of transformers (Note: this is the same case as the outlter discussed 1n Section 3.1.3.d). The anchor bolt stress ratio to allowable 1s 0.79 (21~ stress margin). .
  • 3.2.3 Out-of*plane Floor Amp11f1cat1on

~. 87137.01*0*001 Revision O Page 22 of 30 The 1ocat1on of each cabinet* was reviewed to-determine whether or not out-of-plane floor amplification of the vertical earthquake could be considered s1gn1f1cant. . ~ *

  • The fallowing items were considered to be stgntftcant 1n th1s review:
a. Floor thickness
b. Dimension of the floor plate which supports the cabinet. The floor. plate is assumed to be the minimum area of floor which is supported on four sides by walls below the floor which:
  • Are concrete walls at least one foot thick

- Extend through to foundation

c. Proximity of the cabinet to any concrete wall which extends

. to the foundation

d. Intennedhte st1ffen1ng of the floor plate by concrete walls that extend down to the foundation
e. Major concentrated masses that may lower the floor plate frequency The review for each cabinet 1s discussed below:
1. Control Cab.1net
  • C*33 Support of cabinet C-33 conststs of 1 2' thick reinforced concrete floor supported on 1 side by a 2' thick concrete wall, on 2 sides by reinforced concrete beams and supported on the fourth side by both a beam and a 2' thick reinforced concrete wa11 above the floor. The dimensions of the floor plate are 32'0" (E-W) and 6'8" (N-S). The panel is located 7'1" West of the Eastern wall.
  • Based on the.size of this floor being smaller than the floor supporting the HCCl and HCC2; the proximity of the equipment to a support wall; and the thickness of
  • the floor being twice that of the MCCl and MCC2 floor, the natural. frequency of this floor is expected to be*

higher than 9.Shz and the maximum vertical acceleration to be less than I~3Bg~ The tise of l.4g for the review is judged to be conservative.

2. Motor Control Centers (HCCl &MCC2)

The HCCs are in-a row running N-S. Support of the HCCI.

and HCC2 consists of a l' thick reinforced concrete

  • 87137 .01*0-001 Revision 0 Page 23 of 30 f1 oor supported on a11 4 s1des by concrete wa 11 s (1' and 2' th1ck). All *concrete walls extend through to the foundatton. The dimensions of t.he floor plate are 43' x 48'. The MCCs are 12' West of the 2' thick Eastern concrete wa11 and are 1ocated 1n the middle of the room 1n the N-S directton. D1rectly below the mtdd1e MCCs there ts an additional E*W wall which 1s 1' thick and extends through to thi foundat'1on.

Consumers Power Company has performed an eva1uat1on (Reference 15) on the control room floor and has concluded that the results of the evaluation are applicable to the floor supporting the MCCl and MCC2.

The results of the Consumers Power Company evaluation revealed that the control room floor has a lower bound natural frequency of 9.5 hz. The maximum vertical acceleration 1s l.38g. Therefore, the use of l.4g for the review ts judged to be conservative. .

3. Switchgear 10 The switchgear 10 are 1n a row runntn' N*S* Support for the Switchgear 10 consists of a 2 thick reinforced concrete floor supported on 4 sides by concrete walls. All concrete walls extend to the foundation. The dimensions of the floor plate are 24 1 6* x 48'. Switchgear 10 ts located 9' East of a 2' thick concrete wall that extends to the foundation. In addition, two E-W walls extend West from the Eastern support wall. These two walls provide substantial intermediate support to the floor plate.

Based on the size of this floor being smaller than the floor supporting the MCCl and MCC2; the proximity of the equipment to a support wall; and the thickness of the floor being twice that of the MCCl and HCC2 floor, the natural frequency of this floor is exP.ected to be higher than 9.Shz and the max1m~m vertical acceleration to be less than l.38g. The use of 1.4g for the review is judged to be conservative.

4.0 Surrrnary of Results.

a. Experience Data Representation
  • Subsequent to a walkthrough to ascertain the in-situ seismic characteristics of control cabinet C*33, motor control centers l and 2, and switchgear 1-D; the experience data was reviewed to determine the equivalent representation w1th1n the experience data. The conclusion is that the seismic characteristics of the*

~ 87137.01*0*001 Rtv1s1on O Page 24 of 30 cabinet structures and component anchorages are well represented within the experience data, and the cabinets structures are

  • considered seismically adequate. This conclus1on 1s dependent on CPCo effecting the mod1f1cat1on to bolt control cabinet C-33 to cabinet C-40.
b. Outl 1er1 The wa1 kthrough of the in-situ se1s~1c char~cterht1cs of control .

cabinet C*33, motor control centers *1 and 2, and switchgear l~D revealed. only one out11er. Th1s outlier pertained to the mounting of a number*of transformers 1n 1ROtor control centers 1 and z. Jn some cases the transformers were installed with only three of the four manufacturer design bolts included. A s1mp1e conservative hand calculation was performed and it was determined that the three bolt mounting configuration 1s se*1smiea11y adequate. *

c. Device Anchorage Eva1uat1on via Experience Data During the wa1kthrough tt was determined (except for the outlfer discussed abov') that the device mounting conf1gurat1ons w1th1n control cabinet C-33, motor control centers 1 and 2. and switchgear 1-D were in conformance with standard industrial practice. The mounting conf1gurat1ons of these devices were subsequently reviewed and it was determined that the mounting
  • configurations are represented by mounting configurations of equipment in the experience data. Therefore, the anchorages of the devices are ~onsidered seismically adequate.
d. Review of Existing Calculations Cabinet Anchorage A11 anchorage stress calculations for the control cabinet c-33, MCC 1 and 2, and switchgear 1-D were reviewed and modified to consider NUREG/CR-1833 in-structure seismic response spectra. The following maximum stress rati~s t~ __
  • allowable were found:
  • C-33 3/4* dia. expansion bolts 0.87 MCCl/2 1* dia. expansion bolts 0.91 SWGR-10 112* d1a. expansion bolt~ 0.99 The anchorage calculations reviewed were for the most recent anchorage modifications perfoT;'111ed by URS Blume (URS Blume report to CPCo, dated February 23, 1982).

Cabinet Structural Integrity I

e Rev1s1on o 87i37 .Ol*0-001 Page 25 of 30 Cabinet C-33: No calcu1at1ons were available for review, and no new calculations ware parfonned.

MCCl/2: The available URS Blume calculations were reviewed and modified to consider the NUREG/CR-1833 in-structure floor response spectra. The maximum

. stress ratio to allowable 1s 0.95.

Swgr l*D: No calculations were available for review, and no new calculations were performed.

Device Anchorage Cabinet C*33: No calculations were available for review, and no new ca1cu1at1ons were performed.

MCCl/2: The available URS Blume calculations were reviewed and modified to consider the NUREG/CR-1833 in*structure floor response spectra. The maximum stress ratio to allowable 1s 0.79.

  • SWGR l*D: No calculations were available for review, and no new calculations were performed.
e. Out-of-Plane Ampl1ficatton The floor plate and supporting walls for each of the cabinets were reviewed to determine poss1b11tty of out-of-

. plane amplification of vertical earthquake accelerations.

In each case *1t was determined that out-of~plane *.

amplification would not be significant. In addition, the use of the peak spectral in-structure vertical acceleration (1.4) for all analyses is sufficiently conservative to account for any minor out-of-plane* floor amp1 ificat1ons that might exist.

5.0 Conclusions The conclusion of this evaluation ;s that the following equipment is seismically qua11fied to the NUREG/CR-1833 response spectra:

  • Control Panel C-33 (if minor modification is effected}

Motor Control Centers 1 and 2 Switchgear 1;.o The fo11ow1ng 1.tems were qualified in each case:

cabinet structure

87137. 01 .. 0-001 Revision o Page 2& of 30 cabinet 1nehor1ges

.dev1ca supports The methods of qua11,1cat1on are sunmar1zed 1n the attached table.

e 87137 .01-0-001 Revhfon o Paga 27 of 30

~ -TABLE f

- l Qualtf1cat1on Methods Used ITEM SEISMIC EXPERIENCE DATA ANALYSIS.

C*33.

cabinet structure x cabinet anchorage x x device supports )(

MCCl/2 cabinet structure )(

x cabinet anchorage - x x dev1 ca supports - x x SWGR 1.;.o cabinet structure x cabinet anchorage x x devtce supports )(

  • 87137 .01*0*001 Revision O Page 28 of 30 6.0 References
l.
  • USNRC, *Generic Letter 87*02,Verification of Seismic Adequacy of Mech1n1ca1 and Electrical Equipment 1n Operat1ng Reactors, Unresolved Safety Issue (USI) A-4&*, February, 1987. . .
2. T.A. Nelson,_R.C. Murray, D.A. Wesley, J.D. Stevenson,
  • seismic Review of Palisades Nuclear Power Plant Unit 1 as Part of Systematie Evaluation Program*, NUREG/CR-1833, January 1981.
3. National Tachn1c1l Services latter to Consumers Power Company, November 7, 1987.
4. Senior Seismic Review and Advisory Panel (SSRAP), wuse of Past Earthquake Experience Data to Show Se1sm1c Ruggedness of Equipment 1n Nuclear Power Plants*, Draft, December 1986
5. URS Blume/EPRI, *seismic Anchorage Guidelines for Nuclear Power Pl_ant Equipment*, June 1986.
6. URS Blume Calculation 8013*8.2.l.2, Rev.S, *Alternate Shutdown Panels C-33 and C*40. .
7. URS Blume Calculation 8013-AS, Rev.I, 1 MCCl and MCC2 Anchorages.* *

. a. URS Blume Calculation 8013-A.2.1, Rev.5, *switchgear lC and 10 Anchorage and Support.*

9. URS Blume Calculation 8249*C-002, Rev.1.
10. URS Blume Calculat1~n 8249-C-001, Rev.I.*
11. Bechtel Spec1f1cat1on No. 105121034*c-175.07, Attac~ment 2,.

Rev.O, *seismic Design Requirements for Equipment Located in the Auxiliary Building.*

12. EQE Incorporated, *surrmary of the Seismic Adequacy of Twenty Classes of Equipment Required for the Safe Shutdown of Nuclear Plants, February 1987.
13. Underwriters Laboratory, *tndustr1a1 Control Equipment,"

pub11ca~io~ UL 508 .

14. Bechtel document, "Design Criteria for Evaluation of Expansion Anchors and Base Plates for Seismic Safety System Pipe Supports, Consumers Power Company, Palisades Plant, *.

Bechtel Job No 12447-003, Ann Arbor, Michigan, J.anuary 1980.

e 87137. 01 Rav1s1on O

~0-001

15. Page 29 *af 30 Record of Telephone Conversation V.F. Chan of Consumers Power1987.

29, Company

- to Harry Johnson of £Q[ lncorpor1ted, April I

1.00 0.80 c

o.eo Sei8mic motion bounding apednlm e.

.o

~

Cl Hori~tal pound motion

~

w u

u 0.40 0.20

---Harizont.ol - . ,..an.. *pectrum (SSE) 0.00 -+~-----r--~~-...-------,.-------.--------..-------.-------------------------

0.0 10.0. U5.0 20.0 ~ 38.0 40.0.

Preq~ (Ba)

Ftgure 1: CQ11Partson of SSW loundtng Spect:n* and 0.2g Reg. CUtde d...,,..1.

1.60. llor'zontal Cround. MDt.1Gn Stte **ponse Spectnm (SS

Retrieved from "https://kanterella.com/w/index.php?title=ML18052A969&oldid=2507120"