ML18033A277

Operability Criteria for Evaluation of Lower Drywell Access Platforms - Browns Ferry.

ML18033A277
Person / Time
Site:	Browns Ferry
Issue date:	05/23/1988
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML18033A276	List: ML18033A274 ML18033A277
References
BFEP-TI-C2, NUDOCS 8807180236
Download: ML18033A277 (17)

Text

0% '88 0523 0(g'ef7n TENNESSEE VALLEY AUTHORITY esse e Valley Division of Nuclear Engineering Authority LEAD .TV BFEP-TI-C2 TlTLE..OPERABILITY CRITERIA FOR FVALUATTON OF 7.OWFR DRYWF7,7. ACCFSS PLATFORHS BROWNS FERRY REVlSION RO R1 R2 R5 lSSUE DATE H8'q 89 PREPARED CHECKED REVlENED APPROVED 8807180236 880526 PDR ADOCK 05000260 P PDC

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I REVISION LOG INOPERABILITY BFEP-TI-C2

'f'fi CRITERIA FOR EVALUATION OF LOWER DRYWELL ACCESS Revision Date No. DESCRIPTION OF REVISION Approved

, TVA $ 0534 {CN DES 4.78)

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TABLE OF CONTENTS

~Pa e 1 ~ O INTRODUCTION ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ P 1.1 Description ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ F 1 1.2 Purpose ~ ~ ~ ~ ~ ~

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~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ F 1 1.3 Scope ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ F 1 2.Q DESIGN SPECIFICATIONS ~ ~ ~ F 1 3.0 LOADS AND LOADING COMBINATIONS F-1 3.1 Loading Definitions ~ ~ ~ ~ ~ ~ F 1 3.2 Loading Comb'nations and Allowable St resses ~ ~ ~ F 5 4.0 DESIGN AND ANALYSIS PROCEDURES ~ ~ ~ F 5 5.0 REFH~NCES ~ ~ ~ F 5 Figure 3.1 Combination of Diaamic Reactions from Attac'ned Systems ~ ~ ~ F 6 TABLES:

Table 3.2.1 Loading Combinations And Allowable Stresses ... ~ . F-7 Table 3. 2. 2 Loading Co"binations For Uplift Evaluations ..... F-8

I 1.0 The lover dryvell access platforms include tvo main platforms, one at elevation 584 feet 11 inches, and one at elevation 563 feet 2 inches. The flooring is standard grating, vith 1-1/2-inch by 3/16-inch load bars. The grating and support steel extend from the reactor pedestal to the dryvell shell at elevation 563 feet 2 inches and from the sacrificial shield vali to the dryvell shell at elevation 584 feet 11 inches.

4 The platforms are supported by 24-inch-deep, vide-flange beams radiating from the reactor pedestal and sacrificial shield vali to the dryvell shell. The radial support beams for elevation 584 feet 11 inches are field-welded to header beams in the sacrificial shield vali. T1L radial support beams for elevation 563 feet 2 inches are field-bolted to embedded plates in the outside face of the reactor pedestal. All radial beams are supported by beam seats veldeJ to the dryvell shell. Lubrite pads under the radial beams allov dryvell shell expansion. Shear bars velded to the bottom flange of the radial beams on both sides of the beam seat prevent lateral movement of the beams. Intermediate grating support beams at 6 feet 6 inches maximum spacing are framed betveen the radial beams. Additional support beams are framed betveen both the radial and grating support beams for equipment, HVAC, cable tray, and piping, system attachments. For remainder of dryvel) platforms, see BFN-50-C-7100, Attachment G.

1.2 ~Fur ose The purpose. of these criteria is to establish the requirements for operability evaluation of the 'lower drywell access platforms.

1.3 ~Sco e 1.3.1 The requirements *of this document shall apply to the lover platform structural steel inside the dryvell at elevation 584 feet 11 inches and elevation 563 feet 2 inches as denoted in Reference 5.2.

2.0 ESIG S ECIFICATIONS For this structural design or evaluation, AISC specifications (Ref 5.1) shall be used.

3.0 OADS ND 1.0ADI G COMBINATIONS 3.1 ,pedi Definitions 3,1,1 D Deadload, including structural steel, permanent equiprrent, and attached systems, e.g,, piping, HVAC, cable trays, etc., shall be a minimum of 40 psf.

Lo Outage and maintenance loads, including any moveable equipment loads and other loads 'which vary with intensity and occurrence during an outage, i.e., these loads shall not be present while the plant is operating.

An Lo of 100 psf applied to the loadable open areas shall be evaluated as a baseline outage and maintenance live load for the initial analysis using these criteria.

As concentrated live loads due to outage or maintenance procedures are identified, these loads shall be evaluated against the baseline case, If the results of the concentrated loads exceed l

the baseline case, the concentrated. loads must be evaluated per these criteria.

E Loads due to effects of'BE on structural steel and permanent floor-mounted equipment. This excludes support loads from attached piping, HVAC ducts, and cable trays (these loads are defined in Section 3.1.9).

E' Loads due to effects of DBE on structural steel and permanent floor-mounted equipment. This excludes support loads from attached piping, HVAC ducts, and cable trays (these loads are defined in Section 3.1.9).

Yr Equivalent static load on the structure generated by the pipe whip reaction from pipe rupture restraints attached to the drywell steel.

The application of pipe rupture loads only at those locations where mitigation exists is consistent with the baseline approach to pipe rupture design inside the drywell. Only those locations where GE and/or TVA negotiated pipe rupture mitigation as part of the original design ne d be. considered. See design criteria, BFh-50-C-7105, section 4.2 for further information.

To Thermal effects and loads during startup, normal operating, or shutdown conditions, based on the most critical transient or steady-state cora(~tnt.

Ta Thermal loads under thermal conditions generated by the postulated pipe break accident and including To.

RFE Restraint of free end displacement loads due to thermal reactions from attached piping systems, based on the most critical thermal condition.* RFE loads can be subdivided as follows:

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3.1.8.1 RFEul RFE reactions which contribute to uplift, 3.1.8.2 RFEs - All other RFE reactions, i.e., reactions vhich do not contribute to uplift.

• If reduced conservatism is needed, RFE loads may be defined for upset, emergency, and faulted conditions corresponding to the associated dynamic loading conditions (DYHB, DYNC & DYND).

DYIK) DYNC, and DYND Dynamic Reaction of attached systems, e.g.~ piping,'VAC, cable trays, etc., due to upset (service level B), emergency (service level C), and faulted (service level D) dynamic events, respectively.

Note: Not all attached systems are analyzed for the faulted condition; therefore, some reaction poihts on the floor steel vill only have upset and emergency l~ading.

3.1.9 .1 Dynamic Reaction Phasing reactions from attached systems are

/'ynamic transmitted to the floor steel through rigid restraints and snubbers. Based on the location and orientation of these restraints, different assumptions can be made regarding the phasing of these dynamic loads. These assumptions shall be grouped into three general categories as follovs and they must be cbordinated vith the organization responsible for the system dynamic analysis.

Group A Phasing Knovn When tvo or more dynamic restraints act together to restrain a particular motion or mode of vibration of an attached system, in-phase reaction loads can be assumed. For example, reactions resulting from a matched pair of vertical snubbers on a piping system vould fall into this group.

E Group B Random Phasing When a dynamic restraint acts independently to restrain a particular motion or mode of vibration of an att.ached system, this reaction can be considered randomly phased with other dynamic reactions.

Group C Worsb Case Phasing When tvo or more dynamic restraints act to restrain a particular location of an attached system in more

than one direction, a phasing relationship for these restraints cannot be assumed. For exampl , two .

snubbers w'nicn restrain essentially the same point on a piping system and whose lines of action are skewed to each other ~ould fall into tnis group. The results of these reactions must be summed absolutely to determine an enveloping condition.

If further justification or 'additional analysis can show a phasing relationship between group C restraint loads, these restraints can be treated as group A restraints..

3.1.9.2 Procedure for Determining DYiNB, DYHC, and DYiCD 3.1.9.2.1 As a minimum, the followi'ng procedure shall be us d to det rain the dynamic reaction load cases.

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'A ~ Assign each dynami" .reaction to one of the groups defined in section 3.1.9.1. Tnis requi>es engineering judgment.

Justification for these groupings shall be included as part of tne analysis calculation in accordance with section 4.0 oi tnese criteria.

B. Group A reactions shall be arranged into load sets per the phasing assumed. Each load set shall be evaluated separately with the results of each evaluation constituting a dynamic load step.

4 ~ Each group B reaction shall be evaluated separately with the results o each evaluation constituting a dynamic load step.

D." 5'roup C'reactions stTKTi od azraogea xnM load sets per their potential 'or phasing.

Each reaction in the load set ;-hall be evaluated separately. The absolute summation of the results of each reaction in the load set shall constitute a dynamic load step.

Combine all dynamic load steps using the square root of the sum of the squares (SASS) method to form DYAB, DYNC, or DYHD.

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.1.9.2.2 Figure 3.1 provides

~ ~ ~ a graphic summary of this procedure.

3.1.10 DYBD Larger of DYHB or DYHD. To determine DYBD, screen each DYHB load step against the corresponding DYND load step. (Note that in some instances no DYND load In these cases, use the DYHB load step.) Combinestep'xists.

the screened load steps using the SRSS method to form DYBD.

3.1.11 DYCD Larger of DYNC or DYND. Use the procedure outlined in 3.1.10 above substituting DYNC for DYNB.

3.2 oadin Combinations and llowable Stresses As stated in section 1.1, all radial platform support beams are supported on one end by beam seats welded to the drywell shell.

Since the beam seats do not have hold down capability, the potential for lifting off the beam seats as well as the beam stress must be evaluated. Loading combinations and allowable stresses for stress and uplift evaluations are specified in Table 3.2.1 and Table 3.2.2.

ILK The design and analysis procedures utilized for the drywell steel structures shall be in accordance with reference 5.1.

A summary of analysis procedures as well as )ustification for assumptions shall be documented in a DNE Calculation package.

For the evaluation of framed beam connections the results of the connection test program, as described in Reference 5.3, may be used as a supplement to the requirements of the AISC specifications.

5.0 REFERENCES

5.1 American Institute of Steel Construction (AISC), Specification for the Design, Fabrication and Erection of Structural Steel for

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Buildings, Eighth Edition, 1978.

5.2 TVA drawings 48N442, 48H443, 48N444, 48N1015-series, 48N1016-aeries, 48H1028, and 48H1115 or successor configuration control Document Drawings.

5.3 BFH Test Verification of Drywell Floor Steel Connections (B46870206 001).

5.4 TVA, Civil Design Standard, DS-C1.7.1, "General Anchorage Concrete,"

May 1983.

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GROUP A Phasing Knowa Kl+ K2 I

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I Kg + Kg+I GROUP B Random Phasin DYAB Rl SRSS DYNC

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I lul + luz+zl Ki ~ Individual group A reaction Ri ~ Individual group B reaction Ui " Individual group C reaction r"igure of Dynamic React'o"s from Attache 3.'om'oination Systems

TABLE 3.2.1 LOADING COMBIHATIOHS AND ALLOMABLE STRESSES Combination No Combination Allowable Stress(l)

A. D+ Lo 1.0 S (3)

B. Dw E+ DYNB 1.0 S (3)

C. D+ Lo+ E+ DYED 1.0 S (3)

D. D + E + DYNB + To + RFEs 1.5 S (4)

D + Lo + E' DYNC 1.6 S (4)

F. D + E' DYNC + To + RFEs 1.6 S (4)

G. D t E' DYCD + Y)2) 1.6 S (4)

H. D + DYhD + T + RFEs 1.6 S (4)

D + E + DYBD. +'a + RFEs + Y/2) 1.6 S (4)

D w E' DYCD ~ Ta + RFEs + Y[2) 1.6 (4)

Hotes:

(1) S For structural steel, S is the allovable stress based on elastic elastic design methods defined in AISC (Reference 5.1). The one-third increase in allowable stresses AISC Code (Ref 5.1) due to Seismic loadings is not permitted.

.= -In the above factored load combinations, thermal loads (To and Ta) can be neglected when it can be shown tnat they are secondary and self-limiting in nature and vhere the material is ductile.

The requirements of TVA Civil Design Standard DS-C1.7.1, as applicable, (References 5.4) shall be applied for evaluation and design of concrete anchorages for supports.

(2) Only one pipe vhip reaction should be considered at any given time; however, all postulated breaks for which pipe rupture mitigation structures exist and are attached to dryvell steel must be considered.,

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A LOADING COMBINATIONS FOR UPLIFT EVALUATION(>)

Combination Static Loadin amic oadin

.9D + To + RFEui

.9D DYHB + E

.9D + To < RFEul DYNB + E D .9D DYHC +

.9D + To + RFEul.

E'YllC

+

E'YND

~ 9D + Ta + RFEul + E + Yr

.9D + Ta + RFEul + E' Yr Note:

(l) In each combination, it must be showa that the magnitude of the beam seat reaction due to static loading is greater than the reaction due to dymamic loading, unless an adequate tledoiw exists or the magnitude of uplift is vithin acceptable limits of 0.05 inches.

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