ML20010H380

Mechanical & Electrical Equipment Seismic Qualification Program

ML20010H380
Person / Time
Site:	Haddam Neck, Millstone  File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	09/30/1981
From:	CONNECTICUT YANKEE ATOMIC POWER CO., NORTHEAST NUCLEAR ENERGY CO.
To:
Shared Package
ML20010H374	List: B10308, Forwards Mechanical & Electrical Equipment Seismic Qualification Program.Program Estimated for Approx 1-yr Duration.Concept Developed in Recognition of Util Ultimate Responsibility for Assuring Safe Nuclear Plant Operation ML20010H380
References
PROC-810930, TAC-42493, NUDOCS 8109240403
Download: ML20010H380 (12)

Text

'

Docket Nos. 50-213 50-245 50-336 ENCLOSURE 1 MECHANICAL AND ELECT 31CIs EQUIPMENT SEISMIC QUALIFICATION PLvGRAM HADDAM NECK PLANT MILLSTONE NUCLEAR POWER STATION, UNIT NOS. 1 AfD 2 SEPTEMBER, 1981 8109240403 910915 PDR ADOCK 05000213 P

PDR

', 1.

INTRODUCTION The purpose of this program description is to define the procedures by which the Haddam Neck Plant and Millstone Nuclear Power Station, Units No. 1 and 2 Seismic Category I mechanical and electrical equipment, necessary for safe shutdown of the rcactor, shall be seismically evaluated.

The evaluation shall determine if the necessary cafety function and structural integrity can be assured during and f.llowing a Safe Shutdown Earthquake seismic event. Furthermore, this program shal!,iefine the basis by which equipment shall be selected for review to N. ermine seismic design adequacy.

2.

O'CKGROUND The Haddam Neck Plant and Milicv.ne Nuclear rower Statten Seismic Category I mechanical and electrical equipment was designed and constructed to be capable of a safe shutdown of the reactor in the event of a zero period ground acceleration as defined in the applicable FDSA, FSAR's and current technical specifications. The design basis earthqi.ske used in the original de. w s were essentially characterized by tte.naan centered Housner typ

• gnund response spectra. Varicus methods of treating additional 6..nli"ication through the building structures were employed at the Haddam.. ek and Millstone Nuclear Power Plants.

Thc load combinations, damping values and behavior acceptance criteria used in the design are also defined in the applicable design documents.

The state-of-the-art of seismic analysis and design has changed signifi-cantly during the design, construction, and operation of these three plants.

Some of these changes applicable to one or all of these plants in ',ade:

o Use of mean plus one sigaa ground spectra rather than mean spectra o

rigorous ase of floor respcnse spectra as design input o

horizontal earthqaake motion defined as two orthogonal components rather than a resultant o

changes in damping values cons Vered in design o

changes in methods used to qualify electrical equipment by test Because of the numerous changes which have taken place in the seismic qualification requirements for mechanical and electrical equipment since the Connecticut Yankee and the operating Millstone units were designed and built, this qualification program has been developed to reevaluate the seismic design adequacy of the mechanical and electrical equipment in light of current requirements.

3.

DEFINITIONS In order to assist in the understanding of the scope of effort covered by this qualification program the following nomenclature is defined.

1.

Mechanical huipment - Equipment such as pressure vessels, tanks, heat exchcaqurs, coolers, chillers, pumps, valves, ducts and their suppcrts :vhich are used to process fluids identified as Seismic Category I which are required to shutdown and maintain the nuclear power plant in a safe shutdown condition.

2.

Electrical Equipment - Equipment such as motors, switchgear, motor control centers, relays, control panels, battery racks, M-G sets and transformers and tL91r supports which are used.to aer, instru-ment or control Seismic CFagory I equipmert which ar : recuired to shatdown and maintair the nuclear power 12nt in a sa ' anutdown

+

conditinn.

Electricai equipment contain assemblies of devices formed into a structural entity.

For structural evtsuation purposes e;ectrical equipment are grouped into 3 basic categories:

sa>

Fanel 29ards - Box shaped structures which generally have elec-trical avices mounted on the front face for display purposes.

i Often the structure is large enough to permit personnel entry to service the back of the display panel.

Because of their size lateral restraint is usually provided by lineal structural frame elements to a self-standing back structure or existing building wall.

(b) Ca'anets - Enclosed self-standing box shaped structures made up either of lineal framing members covered with metal piste or metal plate membranes joined by tack welded, bolted or sheet metal screws.

Contained electrical devices usually sit on shelves supported by the cabinet frame or plate.

(c) Racks - Vertical cantilevered planner structural frames supporting attached electricai devices.

3.

Components - Identificable electrical items such as resistors or capacitors, used to construct devices.

Normally, seismic qualifi-cetion is not at the component level.

4.

Devices - Assemblies of ele:crical components designed to perform a specific function.

Normally the smallest assembly of components which has received seismic qualification.

5.

Active Devices - Required to move u* ctherwise change _ state in order to perform its safety function during or following a seismic event.

6.

Passive Devices - Required only to maintain structural or leak tight integrity in order to perform its safety function during or following a seismic event.

For electrical ccmponents, electrical characteris-tics must also be maintained.

_4 4.

PROGRAM DESCRIPTION 4.1 General Seismic Reevaluation of Equipment All seismic Category I equipment or devices.eauired for safe shutdown shall be identified and an individual Equipment or Device Survey Form as shown in Attachment A prepared.

The equipment will be surveyed using the Check List and Procedure shown in Attachment B.

As a result of this survey and an insitu inspection, an Evaluation of Equipment Seismic Resistance Work Sheet shall be prepared for each item of equipment by a team of individual consultnats having expertise in determining the d d gn resista g of mechanical and electrical eqeipment by means of the De 4hi Method.

A sample of the work sheet intended for this use is provided as Attachment C.

A total sample size of the critical equipment identified for a detailed reevaluation shall be approximately 5-10 percent of the Category I equipment identified as required for safe shutdown.

A seismic analysis or test of the critical equipment selected for detail review shall be performed and the resultant seismic design capacity determined.

These detailed analyses and tests shall be used not only to validate the seismic design capacity of the particular equipment analyzed or tested but also to demonstrate the applicability of the Delphi Method for seismic qualification of the Seismic Category I equipment not reevalu-ated in detail.

4.2 Selection of Eqripment for Detailed Reevaluation Selected critical mechanical and electrical equipment using rigoro>s analytical or test methods shall be evaluated in detail to determine current seismic design adequacy.

The types of critical mechanical and electrical equipment and distribu-tion systems to be evaluated are summarized as follows:

(a) Tanks and Vessels (b) Heat Exchangers (c) Pumps (d) Motor Operated Val-es (e) Electrical Panel Boards (f) Electrical Equipment Racks (g) Electrical Cabinets (h) HVAC Equipment (i) HVAC Ducts Evaluation of equipment shall include consideration of active as well as passive modes of failure as applicable.

The criteria for selection of critical equipment to be evaluated are as follows:

/

5 (a) Jritical equipment required for safe shutdown shall be iden-tified based on functional importance.

(b) Based on a walk-through and insitu inspection, rarticular items of equipment shall be selected from the critical list which are considered to exhibit a high sensitivity to seismic loading.

5.

MODELING, ANALYTICAL AND TESTING TECHNIQUES 5.1 Modeling ard Analyticcl Techniques In general the same analytical models and techniques developed for the original seismic design and analysis shall be used in the evaluation of saismic capabilities.

Deviations from such models and techniques shall be identified and used only when the original analysis is clearly inappro-priate.

Thesedeviationsshp}1bebasedonthecurrentstate-of-the-art

,3>

concerning seismic analysis All component analysis shall use elastic systems analysis to proportion loading to the component, attached systems, and supports.

5.2 Testing Efforts shall be made to secure seismic qualification test results,;

manufacturers for devices and equipment where such data currently exists.

The mismic input to such devices instM led in equipment shall be deter-minco by either analytical or insitu low impedance vibratory test methods.

6.

LGEC COMBINATIONS AND ACCEPTANCE CRITERIA 6.1 Load Combinations The equipment seismic review shall be conducted fu the following load combination:

U = 1.0D + 1.0L + E s where:

U=

Limiting lead on the equipment, device or component D=

Dead load L=

Operating live load during normal operation plus any live load occurring as a direct result of earthquake loading.

Live loads shall include thermal effects in those cases where thermal effects include loads which are considered as primary (i.e.

vessel nozzles and component supports)

E = Safe Shutdown Earthquake load s

6.2 Acceptance Criteria For passive devices (structural and ieak tight integrity only) total stresses resulting from the loading, U, shall be limited as defined in the FSAR except as follows:

(a) Current ASME/ACI Code or Standard Review Plan limits may be used provided material selection and fabrication requirements are comparable to current code requirements.

(b) Actual measured or sampled material propertic; may be used rather than specified minimua yield or crushing strength.

For active devices (must operate or change stato), total stresses resulting from the loading U, shall be limited to normal code allowable plus 20 percent, but in no case shall exceed 0.8 times yield or the onset of non-linear behavior.

Devices qualified by test, to seismic inputs equal to or exceeding the safe shutdown level of earthquake excitation, may be used in lieu of analvris' to qualify components.

6.3 Seismic Input The seismic input to the resvaluation of equipment shall be based on site specific floor response spectra currently under development for the Haddam Neck and Millstone l'acilities.

7.

EQUIPMENT DAMPING Thedampingvaluesusedinthisseismicreviewshallbeggjedcnthe damping values given in Table 1 of Regulatory Guide 1.61 with madi-fications to equ'.pment damping as shown in Table 1 of this program description.

The modification of damp;ng values used in tiiese criteria are based on the recommendations and data contained in References 5, 6, 7, and 8.

0

-as.

l 8.

REFERENCES (1) Corotis, R.

B., et. al. "Delphi Method:

Theory and Desigi. Applicstion,"

'Vol. St6 Journal Structural Division of American Societv of Civil Engineers, June 1981.

' (2) Boiler and Pressure Vessel Code,Section III, Appendix N - Dynamic Analysis Methods, American Society of Mechanical Engineers, 1980.

(3) Standard Revier P?an Section 3.7.2, " Seismic Analysis", U.S. huclear Regulatory Cow.ssion, June 1975.

(4) Regulatory Guide 1.51, " Damping Values for Seismic Design of Nuclear Power Plants," U.S. Atomic Energy Commission, October 1973.

(5). Lawrence Livermore Laboratory, Seismic Review of Dresden Nuclear Power Station - Unit 2 for Systematic Evaluation Program, 4

NUREG/CR-0891, April 1980.

(6) Bohm, G. J., " Damping for Dynamic Analysis of Reactor Coolant Systems,"

Presented at the National Topic Meeting, Water Reactor Safety of the American Nuclear Society, Salt Lake City, 26-28 March 1973.

(7) Morrone, A., " Damping Values of Nuclear Power Plant Components,"

Report WCAP-7921 Westinghouse Nuclear Energy Systems, Nov. 1972.

(8) Stevenson, J. D., " Structural Damping Values as a Function of Dynamic-Response Stress and Deformation Levels", Nuclear Engineering and Design, Vol. 60, 1980.

I

.5

..~,va

• ++,-,

y

--,-r-

---?-

-yar v+

w

• e-.*

rrv-*'

-- sw r,v.. n -

r wv=-

--cy._-

+-v-ww<

-+-

y

=~- - - --- - - - *- ~ ~ -

+ +- t

-- ' - ^ + - -

.g.

TABLE 1 DampingValues-PercentCriticaltobeUsedg)the 3eismic Margins Review for Passive Components Structure or Component Percent Critical Damping Large diameter piping systems 4.0(I)

Pipe diameter 12_in.

Small diameter piping systems 3.0(I)

Pipe dis:::eter 12 in.

Welded Steel Structures 4.0(3)

Bolced Steel Structures 7.0(3)

Welded Steel Components (2) 4.0 Bolted Steel Components (2) 7.0 Reinforced Concrete Structures 7.0(3)

Prestressed Concrete Structures 5.0(3)

(1) egg,vyje s are based on test performed by Westinghouse Electric

~

(2) Thesedampingvaluesareconsistentwithdampingvaluesdefinedfgg) welded and bolted st ctures and by review of existing test data (3)

R.G. 1.61 OBE damping levels shall be used as structural damping in generation of floor response spectra where total calculated stresses in the structure for the SME do not exceed 1/2 yield.

(4) Damping values used in evaluation of active components shall be reduced in the same proportion of OBE to SSE damping values as defined in Table 1 of R.G. 1.61.

_g.

ATTACHMENT A EQUIPMENT OR DEVICE SURVEY FORM I.D. No.

Item

Description:

Location:

1)

General Description, Photograph, or Sketch of Supports:

2)

Check List:

A)

Base Plate:

1) Base Plate Dims:

2) Bolt Holes:

a1 Number b) Spac %g c) Size d) Edge Distance B)

Specify means of attachment of equipment to structure:

1) Bolted:

a) Poured in Place Bolts:

b) Expansion Anchor Bolts:

c) Welded Bolts:

3) Other:

C)

Description of Additional Attachments (bracir,g, gussetts, etc. )

1) Number:

2) Lviation:

- o I.D. No.

3) Dimension:

4) Size:

D)

General Condition - Visual Inspection:

1)

Welds (AWS D1.1 para. 8.15.1) a)

Cracks:

b)

Fusion:

c)

Craters:

d)

Profiles:

e)

Fillet Size:

2)

Bolts:

a)

Fit:

b)

Relative Size (Bolt to Hole):

c)

Material:

E)

General Equipment Dims:

F)

Estimated Weight:

Estimated Location of C.G.:

G)

Is component supported or restrained by bicek wall Yes No H)

General Comments:

ATTACHMENT B CHECK LIST AND PROCEDURE LOR INVESTIGATION OF EQUlPMENT TO EVALUATE SEISMIC DESIGN ADEQUACY The survey censists of the fol'9 wing activities:

1.

An "as built" description of the means of attachment of each of the equipment listed to the floor or other support system.

2.

Identify fcc each equipment listed tne following:

a.

Numbc: and location of holes drilled or punched into the plate electrical equipment base as well as base dimensions and thickness.

b.

Specify the means by which the electrical equipment is attached to support structure.

(1) Anchor bolts embedded in concrete support structure (Poured in Piace)

(2) Anchor bolts embedded in concrete support structure (Expansion Anchor)

(3) Anchor bolts welded to embedded or other steel structure (4) Dimension anc thickness of cabedment steel if available (5) Plug we?d 'using existing holes) to embedded or other steel structure (6) Tack welds to embedded or other steel structure (7) Fillet welds to embedded or other steel structure (8) Other c.

Description of the attachments to include number, location, dimension and size of the attachment.

d.

General condition of the attachment.

(1) Visual inspection of the welds in accordance with the requirement of AWS Dl.1 Para. 8.15.1 Visual Inspection (2) -Visual inspection of bolts to identify fit, size of holes relative to bolt size and tightness of nut and identifica-tion of bolt material if possible-e.

Give overall dimension of electrical equipment.

f.

Give estimate of equipment weight and location of C.G.

WORK SHEET EVALUATION OF EQUIPMENT SEISMIC RESISTANCE System Title Device litle Equipment Title I.D. No.

Horizonta'. resultant and vertical component 1.

C3mments on degree of restraint, rigidity acceleration levels input to equipment that it of supports, stiffness, mass, etc.

is adjudged capable of surviving to the first failure mode with probabilities noted.

2.

Estimate of dominant or fundamerstal frequencies.

3.

Description of expected first fai.w:2 mode.

g Level 4.

..; rints on the condition of the item and Probability, i,- aupport as to the degree of corrosien, Percent Horizontal Vertical bolt tigntoess, etc.

90 50 5.

Comments on damaging effects of surrounding 10 components.

6.

Recommended codifications, tests, analyses, etc.

6.1 As a function of acceleration level.

6.2 Independent of acceleration level.