PY-CEI-NRR-0336, Clarifies & Resolves NRC Concerns Re Design for LOCA-related Hydrodynamic Loads (SER Open Item 9).Draft Acceptance Criteria for Mods to Pool Dynamic Load Design, Info Re Submerged Drag Loads & Proposed Revs to FSAR Encl

Clarifies & Resolves NRC Concerns Re Design for LOCA-related Hydrodynamic Loads (SER Open Item 9).Draft Acceptance Criteria for Mods to Pool Dynamic Load Design, Info Re Submerged Drag Loads & Proposed Revs to FSAR Encl

ML20135G565
Person / Time
Site:	Perry
Issue date:	09/13/1985
From:	Edelman M CLEVELAND ELECTRIC ILLUMINATING CO.
To:	Youngblood B Office of Nuclear Reactor Regulation
References
PY-CEI-NRR-0336, PY-CEI-NRR-336, NUDOCS 8509190422
Download: ML20135G565 (25)

Text

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P O. Box 5000 - CLEVELAND. OHIO 44101 - TELEPHONE (216) 622-9800 - lLLUMINATING BLDo - S$ PUBLICSQUARE Semng The Best Location in the Nation MURRAY R. EDELMAN VICE PRESIDENT NUCLEAR September 13, 1985 PY-CEI/NRR-0336 L Mr. B. J. Youngblood, Chief Licensing Branch No. 1 Division of Licensing U.S. Nuclear Regulatory Comraission Washington, D. C. 20555 Perry Nuclear Power Plant Docket Nos. 50-440; 50-441 Pool Dynamic Loads SER Open Item (9)

Dear Mr. Youngblood:

The purpose of this letter is to provide further clarification to our May 16, 1985 letter and to resolve staf f concerns regarding the PNPP design f or LOCA-Related Hydrodynamic Loads.

Attachment 1 to this letter provides a copy of the Draf t Acceptance Criteria used to modify the GESSAR 11 methodology in the PNPP design for LOCA-related pool dynamic loads. It is Appendix C to the Draft Technical Evaluation Report on Mark III LOCA-Related Hydrodynamic Load Definition provided by letter dated October 8,1982 f rom Mr. T. Speis (NRC) to Mr. H. Pfef ferlen (GE). CEL committed to meet this version of the draf t acceptance criteria in a letter dated January 31, 1983. This commitment was reflected in Appendix 3B in Amendment 11 to the FSAR dated February 15, 1983.

Attachment 2 to this letter is a supplemental clarification of our response to Item 4 of the May 16, 1985 letter, regarding submerged drag loads due to chugging (3B.8.1.6). This response further supports the conclusion that, based on our design methodology, the drag loads associated with the chugging phase of a LOCA are bounded by the conservative LOCA loads used in our design.

Attachment 3 consists of the proposed revisions to FSAR Appendix 3B pages to clarify our design methodology.

8509190422 850913 PDR ADOCK 05000440 E PDR e

la ls

i Mr. B. J. Youngblood September 13, 1985

. PY-CEI/NRR-0336 L j~

Finally, Attachment 4 provides the methodology of our evaluation of the impact

loads on short structures and' structures close to the pool surface, using the revised NRC impact criteria.

i We believe that this information resolves all outstanding NRC staff concerns regarding the LOCA-related hydrodynamic load definition utilized at PNPP and should enable Outstanding Issue (9) to be resolved in the next supplement to the SER.

Very truly yours

@k Murray R. Edelman Vice President Nuclear Group j MRE:njc Attachments l cc: Jay Silberg, Esq. ,

John Stefano (2)

, J. Grobe

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o ATTACHMENT l uf .

h, UNITED STATES o

3 NUCLEAR REGULATORY COMMISSION f wAsmNcToN. o. c. 20ses N *...*) 00T 8 1982 Mr. Hank Pfefferlen, Manager BWR Licensing Programs General Electric Company M/C 682 175 Curtner Ave.

San Jose, CA 95125

Dear Mr. Pfefferlen:

Enclosed is a copy of the staff's draft technical evaluation report on the Mark III LOCA-related hydrodynamic load definition for sur review and comment. Our evaluation was based on the information contained in Appendix 3B of GESSAR-II and the reports refenrced therein. In your review, please focus on whether we correctly interpreted the informa-tion you furnished and identify those treas where we are quoting infor-mation you consider to be proprietary.

We plan to issue the final version of this report by January 1983 and will need any comments the General Electric Company may have on the ma-h terial contained in the report by early December 1982. If you believe that 6 meeting to discuss your comments on our report would be useful, please contact Mr. M. Fields at 492-9417 to arrange for such a retting.

Sincerely.

Themis P. Spets. Assistant Director for Reactor Safety Division of Systems Integration

Enclosure:

As stated I

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I 4 l Appendix C NRC Acceptance Criteria for LOCA-Related Mark III Containment Pool Dynamic Loads The following acceptance criteria were developed from the staff's review of Appendix 3B of GESSAR-II 238 Nuclear Island (GESSAR) and the supporting analytical and experimental programs as referenced therein. The staff has determined that the procedures described in the GESSAR are accsptable for evaluation of the Mark III conta16 ment response to LOCA-related pool dynamic loads with the following exceptions, modifications, qualifications and/or clarifications:

1. 0 Pool Swell Loads 1.1 pool Swell Velocity

/

The water slu; velocity V tc be u:ed fer me cetereinaticn of slug drag loacs, )

as well as slug impact Icads as prescribed in 1.2,1.3 and 1.5 below, shall be determined frcm the relation:

V = 5 H (2.6 - 0.506 JH); H < 10 ft, and

• Y = 50 ft/sec H > 10 ft .

In these relations, V is the slug velocity in feet per second (fps), H denotes the height (in feet) above the initial pool surface.

1. 2 Pool Swell toads _on Structures Attached to the Containment Walls The GESSAR-II specification for these loads is given in Section 38.6.1.5. It is based on steady drag at a flow velocity of 40 ft/sec. The specification needs to be modified to make it acceptable.

8 (1) If the local pool swell velocity', as specified in Section 1.1 above, is greater .then 40 f t/sec, the drag pressures obtained by the GESSAR

r eG. um ureen eu s s e ve ce co 11: 4< e.

,, g g specification shall be multiplied (V/40)2, where V is the local pool velocity in ft/sec.

(2) If the frontal area of the structure is not immersed prior to pool swell, it will experience an impact force. This must be included in the specification.

For half wedge protrusions the force history during impact shall be determined from Figure C-1. The local velocity of impact (needed in '

Figure C-1) shall be taken from the specification in Section 1.1, corre-sponcing to the height where the wedge is first fully submerged. If the lower portion of the wedge is initially submerged, the same impact history is applied except the abscissa is replaced by Vt/h, where h is the "unsubmerged height of the wedge.

If the wedge angle is other than 45', the following ratios can be used after obtaining the force history for a 45* wedge from Figure C-1.

tO F

= (50? p) e t p, and (C-1)

= cot S

• 45 I

where $ is the wedge angle.

1 .

For horizontal ledges the impact force shall be determined in the following manner:

(a) The force history will have a triangular shape as shown in Figure C-2.

(b) Determine the hydrodynamic mass of impact (per unit area) for flat targets from Figure 6-8 of NEDE-13426). Use b (and not b/2) for target width.

O .

C-2

D 0

. b

. . . 4 gP ,

. t a time, sec. ,

3 p = density, slugs ft F = impact force,1bf .

W >

. U i

b s/2 . .,

( -

Drag .

. \

. g .

. \

0- - -

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i.s . i.o 2Vt/b Figure C-1 Impact Force (per unit length) on Wedge-$ha' ped Protrusions from the Containment Well ..

C-3

. -- . . . _ __ . _ . . - _ _ . __ __ ._ ~ _ . . _ _ __ ___ _ __ _ _ . _ _ _

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. +

1 -

a i .

,a b

-*- 2 +l- .

1 V

i V .

. , 4

, F 4--.-- -

V I

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j Figure C-2 Impact Pressure on Nortrontal Ledges Attached 4e Containment Wall i

C'S _- .-

l

~

(c) Calculate the impulse using the equation b 1

~ IP*T Y " (32.2)(144) (C-2) where:

Ip = impulse per unit area, psi-sec p a hydrodynamic mass per unit area, ibm /ft, from,(b) above.

V

= impact velocity, ft/sec, determined according to Section 1.1.

(d) Calculate the pulse duration from the equation t=0.02h(h) (C-3) where:

C 1 = pulse duration, sec H = height above tr.c pec1, feet b/2 = width'of the ledge, feet V

= impact velocity, ft/sec, determined according to Section 1.1 (e) The value of P, will be obtained using the following equation:

P, = 2 Ip /t ,

(C-4) where: ,

t P, = the peak pressure amplitude, psi.

1.3 Bulk Impact loads on Small structures "Small structures", in the present context, are defined as beams and pipes O ita 1 t r i ai a taa ao i rs r sa a 2o $aca - rar ta. tructur ta-bulk impact specification, as described in Section 38.10.11 of CESSAR-II, is C-5

-,-------m - -,- -

p w , ,- -- ,-v w , -- -

.- 1 1

acceptable with the specific limitations discussed in Section 380.3.2.33 of Attachment 0 (Question / Response 38.33).

• These limitations are:

o (1) Targets must have combinations of widths and natural frequencies such that Figures 38.33-1, 2, 3 and*4 indicate them to be in the "GESSAR conservative" region with respect to the V = 50 ft/see pool velocity curve.

(2) There are no structures smaller than 4 feet long.

(3) There are no structures closer than 6 feet above the pool.

For those structures that do no meet limitations 2 and/or 3, the pulse width and amplitude of the bulk impact specification described in Section 38.10.11 of GESSAR-II should be modified as follows:

() (1)

For structures smaller than four feet long, reduce the GE specified pulse width (7 esec for radial criented structuros; 2 msee for circumferential oriented structures) by f, where x is the actual length of the structure in question.

(2) .

For structures closer than six feet above the pool, reduce the GE specified pulse width by {, where y is the actuale 'levation of structure in question.

For structures less than 10 feet above the pcol, the amplitude may be reduced by .

=

3 h = i g (2.6 - 1.6 h )8 max max

• where A is the amplitude at a structure H feet above the pool surface and A ,,

T is the GE-specified amplitude for bulk impact on small structures above the

'Q_,) Voole O

9 C-6 -

/ 1. 4 Froth Impact Leads The froth impact specification is applicable between an elevation of 19 feet above the pool and the HCU floor.

Over open areas of the HCU floor this specification extends to an elevation of 26 feet for flat structures and 28.5 feet for pipes. . Between these elevations and 30 feet the froth drag specificatico in GESSAR-II, Section*38.12 is app 1 feeble.

The forcing function for froth impact shall be an Isosceles triangle with a maximum amplitude given in Figure C-3.

The pulse duration shall be chosen such as to give a maximum OLF with a triangular pulse.

For elongated structures that span the annulus of the wetwell, pulse durations shorter than 50 esec need not be considered.

1.5 Drac_ Loads The GE5SAR-II specification for drag loads on small structures, as describ h in Section 38.10.2, is acceptable with the following limitation.

If the local pool velocity, as specified in section 1.1 abeve, is grcater than ao ft/sec ,

the dra; forces cbtained by the GESSAR-!! specification shall be ymultiplied a (V/40)2 where V is the local velocity in ft/sec.

If Figure 38-75 in GESSAR-II is used for drag loads on plates and if the -

shorter side (b) is attached to a well, the abscissa of the graph becomes 2a instead of a/b.

2.0 loads on Submerced Structures The procedures for the codpu'tation of loads on su6 merged structures as in sections 3.8.8 to 3.8.8.1.1 and Attachment L of GESSAR are acceptablej subject to the limitations and/or modifications of Section Attachment 0. 3.8.0.3.2.31 of In particular, the computation of acceleration loads on non-cylindrical structures and the evaluation of standard drag for C0 loads must be based on the Mark I Acceptance Criteria (NOREG 0661) as described in the

' responses to questions 3.8.31(b. f t), (c. ii) and (c.111) in Attachment 0.

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Figure C 3 NRC Acceptance Criteria for Froth Impact: * ,

Peak Amplitude of Pressure Pulse

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3.0 Impact loads on Structures Above the Weir Annulus (4

-;TW The staff finds ^th4 GESSAR-!! impact specification on structures above the weir wall, with the exception of radial structures within one foot of the top

,; of weir wall.

The stresses in these structures must be increased by a multiplier. ,

This multiplier is 1.0 when the natural fregancy of the structure is less than 200 Hz, 1.8 when the natural frequency is greater than 500 Hz with a linear ramp between these values.

Forstructureslocatedbetweenzeroand0.25feetabovethe[a wall, flat pool impact should be considered (e.g., the acceptance criteria in Section 2.7 of Appendix A, NUREG 0661 is appropriate for flat pool impact). The velocity at impact for these structures shall be taken at 4 ft/sec.

e C

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ATTACHMENT 2 RESPONSE TO 35.8 1 6 Chugging Loads For piping and other items in the pool, the conservative PNPP design definition used for SRV and LOCA submerged drag loads, envelopes the GESSAR 11 chugging drag load when combined with the GESSAR 11 Nethod of Images technique for calculating SRV drag loads.

For piping, the LOCA submerged drag load was calculated based on bubble pressure attenuation (10psid applied statically with a minimum DLF of 1 2).

The chugging DLF times the method of images pressure calculated as shown in CESSAR 11 section 3BL2.9 is significantly less than the LOCA load used.

Therefore, the conservative LOCA submerged drag load definition bounds the SRV + Chug load definition for piping. '

For the columns, chugging was included in the design using the appropriate DLF.

For the strainers, a DLF was calculated and when multiplied times the chugging pressure is less than 0 5 psi. This load, when combined with SRV, is bounded by the submerged drag load of SRV 1 valve 2nd pop. Therefore, the SRV + chug load combination is bounded by the SRV second pop used for design of the strainers.

i 1

0 1

i

ATTACHMENT 3 6

6 APPENDIX 3B CONTAINMENT LOADS e

a

_a- _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . - . _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ . _ _ _ _ _ _ _ _ . _ . . . . . _ _ _ _ . . _ . - . _ . _ _ _ _ _ . _ _ _ . _ _ _ _ _ _ . _ _ . .

D-PREFACE h is section has been revised to delete the GESSAR Appendix 3B which had been reproduced as Appendix 3B of the PNFP PSAR. The following section follows the format of GESSAR II - Rev. 2 Appendix 3B and provides a step-by-step Perry

. specific comparision. GESSAR II, as modified by Draft Acceptance Criteria a (Reference 1: Appe:ndix C to the Draf t Technical Evaluation Report on Mark III l LOCA-Related Hydrodynamic Load Definition provided by memo dated 10/8/82 from Mr. Thesis P. Speis (NRC) to Mr. Hank Pfefferlen (GE))is the basis for the PNPP design.

G 5

35-1

m ,m.(-W--+.g

APPENDIX 35 CONTATNMENT IDADS

38.1 INTRODUCTION

i

. No deviations.

3B.1.1 CONFIRMATORY TESTINC i

No deviations.

38.1.2 DEFINITION OF LOCA No deviations.

35.1.3 DESICN MARCINS No deviations.

l 38.2 REVIEW OF PHENOMENA No deviations.

38.2.1 DESIGN BASIS ACCIDENT (DBA)

CESSAR FiBures 3B-2 through 38-6 are not applicable to Perry. See FSAR Figures 3B-1 through 38-5.

38.2.2 INTERMEDIATE BREAX ACCIDENT (IBA)

No deviations.

38.2.3 SMALL BREAK ACCIDENT (SBA)

The Perry drywell pressure resulting from an SBA is increased from 3.0 psid, as required by CESSAR, to 3.3 psid.

3B.2.4 SAFETY RELIEF VALVE ACTUATION No deviations. i 9

38-1 -

9

~e o oww - e s.',we_. m , . me ma ,e +en

,. ~,~.y. . -.-g..,, _y,..- . . , . ----sr --. -._--.m, - w ,---w,

3B.2.5 OTHER CONSIDERATIONS

\

No deviations.

3B.3 DYNAMIC LOAD TABLE No deviations.

3B.4 DRYWELL STRUCTURE No deviations.

3B4.1 DRYWELL LOADS DURING A LARCE BREAK ACCIDENT No deviations.

3B.4.1.1 Sonic Wave No deviations.

3B.4.1.2 Drywell Pressure CESSAR Figure 3B-10 is not applicable to Perry. FSAR Figure 6.2.11 shows the Perry dryvell pressure response to a main steam line break (DBA).

38.4.1.3 Hvdrostatic Pressure No deviations.

3B.4.1.4 Loads on the Drywell Wall During Pool Swell No deviations.

35.4.1.5 condensation Oscillation Loads CESSAR Figure 3B-17 is not applicable to Perry. See FSAR Figure 3B-6 for the distribution of condensation oscillation loads on the drywell.

3B.4.1.6 Fallback Loads No deviations.

38.4.1.7 Negative Load During ECCS Flooding No deviations.

3B.4.1.B Chugging No deviations.

38.4.1.9 Loads Due to Chugging

, No deviations.

I 3B-2

l

~

38.4.1.9.1 Chugging Loads Applied to Top Vent No deviations.

38.4.1.9.2 Pool Boundary Chugging Loads .

CESSAR Figures 3B-28 through 3B-31, and 3B-34 and 3B-35 are not applicable to Perry. See FSAR Figures 38-7 through 3B-12.

38.4.2 DRYWELL LOADS DURINC INTERMEDIATE BREAK ACCIDENT No deviations.

38.4.3 DRYWELL DURING SMALL BREAK ACCIDENT No deviations.

38.4.3.1 Drywell Temperature No deviations.

38.4.3.2 Dryvell Pressure No deviations. ,,

38.4.3.3 Churting

(

No deviations.

3B.4.4 SAFETY / RELIEF VALVE ACTUATION No deviations.

35.4.5 LRYWELL ENVIRONMENTAL ENVELOP No deviations.

3B.4.6 TOP VENT TEMPERATURE (CYCLINC) PROFILE DURING CHUCCING No deviations.

3B.4.7 DRYWELL MULTICELL EFFECTS No deviations.

38.5 WEIR WALL No deviations.

38.5.1 WEIR WALL LOADS DURING DESICN BASIS ACCIDENT No deviations.

(

38-3 /

se =e. ,..w -+~ - tm. -

,,y .

~3B

...5 1 1 Sonic Wave No deviations.

3B.5.1.2 Outward Load During Vent Clearina No deviations.

~

35.5.1.3 Outward Load Due to Vent Flow No deviations.

38.5.1.4 Chugging Loads No deviations.

Invard Load Due to neRative Drywell Pressure

. 38.5.1.5 Deviations from GESSAR as required by the NRC Draft Acceptance Criteria l

. 3B.5.1.6 Suppression Pool Fallback Loads No deviations.

3B.5.1.7 Hydrostatic Pressure No deviations.

I ~

38.5.1.8 Safety / Relief Valve Actuation No deviations.

35.5.1.9 Condaasation 1

No deviations.

35.5.2 WEIR WALL LOADS DURINC AN INTERMEDIATE BREAK ACCIDENT No deviations.

38.5.3 WEIR WALL LOADS DURINC A SMALL BREAK ACCIDENT No deviations.

38.5.4 WEIR WALL ENVIRONMENTAL ENVELOPE No deviations.

38.5.5 WEIR ANNULUS MULTICELL EFFECTS No deviations.

i, (

38-4 9

• ,ee-,,w_g -e ,w o- - ~- . ,,--.,.,.# ,  %,g m v- g- r , - , - g , -p--- , - - -

e- 7-,- -,-,r- -

38.6 CONTAINMENT I

No deviations.

38.6.1 CONTAINMENT LOADS DURING A LARCE STEAMLINE BREAK (DBA)

CESSAR Figures 35-2 through 35-6 are not applicable to Perry. See FSAR Figures 3B-1 through 38-5.

a 35.6.1.1 Compressive Wave Loadina No deviations.

35.6.1.2 Water Jet Loads No deviations.

38.6.1.3 Initial Bubble Pressure No deviations.

38.6.1.4 Hydrostatic Pressure No deviations.

3b.6.1.5 Local Containment Loads Resulting from the Structures at or Near the Pool Surface Deviation from CESSAR as required by the NRC Draft Acceptance Criteria.

35.6.1.6 Containment Load Due to Pool Swell at the HCU Floor (Wetwell Pressurization)

Th( Perry H7U finar is approxim1tely 27 feet ah>ve the suppressien po<il surface and has been designed for 10 paid across the total area of the platform (structural steel plus grating). This was reduced from the CESSAR specification due to the Perry HCU floor being 7 feet higher than the CESSAR standard. In addition, a plant unique analysis showed a peak calculated pressure differential equal to approximately 5.4 psid based upon a design open area ratio of 30 percent of the total HCU floor area, (Refs. 2, 3 & 4).

GESSAR Figure 35-58 is not applicable to Ferry.

38.6.1.7 Fallback Loads No deviations.

38.6.1.8 Post Pool-Swell Waves No deviations.

35.6.1.9 condensation Oscillation Loads CESSAR Figure 38-17 is not applicable to Perry. See FSAR Figure 38-6 for condensation oscillation loads on containment.

38.6.1.10 Churrina No deviations.

38-5 e

38.6.1.11 Long-Term Transient No deviations.

38.6.1.12 containment Environmental Envelope No deviations.

g 35.6.2 CONTAINMENT LOADS DURING AN INTERMEDIATE BREAK ACCIDENT No deviations.

38.6.3 CONTAINMENT LOADS DURING A SMALL BREAK ACCIDENT No deviations.

38.6.4 SAFETY / RELIEF VALVE LOADS No deviations.

38.6.5 SUPPRESSION POOL THERMAL STRATIFICATION No deviations.

38.6.6 CONTAINMENT WALL MULTICELL EFFECTS No deviations.

38.7 SUPPRESSION POOL BASEMAT LOADS No deviations.

33.8 LOADS ON ETRUCTURES IN THE SUPPRET.SION POOL No deviations.

38.8.1 DESIGN BASIS ACCIDENT No deviations.

38.8.1.1 Vent Clearing Jet Load No deviations.

38.8.1.2 Drywell Bubble Pressure and Dram Loads Due to Pool Swell The PNPP design basis for drywell bubble pressure and drag loads conservatively uses the LOCA bubble pressure. A comparison of the PNPP load methodology and the CESSAR II methodology is given in Section 3BL.2.3 of the FSAR.

32.8.1.3 Fallbsek Loads I

No deviations.

38-6

. _ . ~ . _ _ _ _ . ... ._.

38.8.1.4 Condensation Loads LOCA condensation-oscillation drag loads are bounded by the PNPP LOCA bubble pressure drag load methodology. (Reference 4) l 0

35.8 1.5 Chugging Chugging drag loads are bounded by the PNPP LOCA bubble pressure drag load metholology. (Reference 4 & 5) l 358.1.6 Compressive Wave Loading No deviations.

38.8.1.7 Safety / Relief valve Actuation The PNPP design basis for safety / relief valve quencher air bubble drag loads is conservatively based on the maximum quencher bubble pressure. A comparison of the PNPP load methodology and the GESSAR II load methodology is given in Section 3BL.3.2. of the FSAR.

31.9 LOADS ON STRUCTURES AT THE POOL SURFACE Ae required by the NRC Draf t Acceptance Criteria, the Perry analysis used a velocity ranging from sero fps at the pool surface to a maximum of 50 fps as a function of height; instead of the constant 40 fps velocity specified in GESSAR Table 38-2, to calculate pool swell drag loads.

38.10 LOADS ON STRUCTURE BETWEEN THE P00L SUkFACL AND TnE llCU )LOORS No Deviations.

35.10.1 IMPACT LOADS lapact loads are calculated in accordance with CESSAR as modified by the requirements of the NRC Draf t Acceptance Criteria.

The design basis for bulk pool swell impact loads on small structures less than 4 ft. long and/or 6 ft. above the pool have been evaluated using an alternative method. (Reference 5) 35 10 2 DRAG LOADS Drag loads are calculated in accordance with CESSAR as modified by the requirements of the NRC Draft Acceptance Criteria.

33-7

35.10 3 FALLBACK LOADS No deviations.

35.11 LOADS ON EXPANSIVE STRUCTURES AT THE HCU FLOOR ELEVATION.

Yhe only expansive structure in Perry in the pool swell region is the steam tunnel, which is designed in accordance with the NRC Draf t Acceptance Criteria.

(References 1, 3 & 4) 35 12 LOADS ON SMALL STRUCTURES AT THE ABOVE AND THE HCU FLOOR ELEVATION Deviation f rom CESSAR as required by the NRC Draf t Acceptance Criteria.

35.13 REFERENCES

1. Draf t NRC Accepanee Criteria for. LOCA Related Mark III Containment Pool Dynamic Loads Appendix C of Attachment to NRC letter from T.P. SPeis NRC, to H. Pfefferlen, CE, dated October 8,1982.

2. CEI letter, PY-CEI/NRR-0010L from M. R. Edelman, CEI, to 5. J. Youngblood, NRC, dated January 31, 1983.

3. CEI letter, PY-CEI/NRR-0055L from M. R. Edelman, CEI to B. J. Youngblood, NRC, dated June 20, 1983.

4. CEI letter, PY-CEI/NRR-0123L f rom M. R. Edelman, CEI to B. J. Youngblood, NRC, dated July 11, 1984.

5. CET letter, PY-CEI/NRR-0235L f rom M. R. Edelman, CET to E. J. Youngblood, Nac, dated May 16. 1985.

6. CEI letter, PY-CEI/NRR-0336L f rom M. R. Edelman, CEI to B.J. Youngblood, NRC dated September 13, 1985.

35-8

ATTACHMENT 4 PERP.Y NUCLEAR POWER PLAlfr EVALUATION OF IMPACT LOADS ON SHORT STRUCTURES AND STRUCTURES CLOSE TO THE POOL The design basis for bulk pool swell impact loads on structures less than 4 feet long and/oc closer than 6 feet to the initial pool surface is based on the impact method given in Gessar II (Reference 1) as modified by the NRC Draf t Acceptance Criteria (Appendix C to the Draf t Technical Evaluation Report on Mark III LOCA-Related Hydrodynamic Load Definition provided by meno dated 10/8/82 from Mr. Thomas P. Speis (NRC) to Mr. Hank Pfef ferlen (CE)). This report presents the methodology used for evaluating structures which are outside the range for which the NRC Acceptance Criteria (NUREG-0978) Reference 2 finds GESSAR II acceptable.

All structures (beams, piping, pipe supports, & miscellaneous structural steel) have been identified.

Summary All beams, piping, pipe supports, and miscellaneous structural steel which are outside the range for which the NRC Acceptance Criteria (NUREG-0978) Reference 2 finds GESSAR II acceptable are being evaluated. We will demonstrate that

! sufficient design margin exists between the original design basis pressure and the impact pressure calculated using the methodology listed below.

Method The impact loading for each component was determined using the following:

. (a) Pulse Duration The impact pulse duration was calculated using the suggested Haisc criteria (Reference 3) or the Mark 11 criteria (NUREG-0487) Reference 4, whichever was greater.

7"(sec) ,

(b) Impact Pressure The impact pressure is calculated using the hydrodynamic mass of the target which is a function of the target shape (flat or cylindrical) and orientation above the pool (radial or circumferential). The hydrodynaste mass is determined from NEDE-13426P (Reference 5), Figures 6-8 and 6-9 for radial and circumferential orientation, respectively.

The impact velocity as a function of height above the pool is determined using equation C-1 of the Mark III Acceptance Criteria (NUREG-0978).

V=5H(2.6-0.506/H) H f 10 ft.

V = 50 ft/sec H 7 10 ft.

p

The total impulse is calculated using equation C-4 of Reference 2.

I p= (M H ( * *I where:

f 1, = lePulse per unit area, psi-see M /A = hydrodynamic mass per unit area, Ibe/f t2 H

V = impact velocity, it/sec Using the pulse duration (7) the impact pressure is determined assuming an isosceles triangle loading.

P = 2* Ip /7 (Psi)

The above impact load and pulse duration was used to evaluate each component.

Methods used to evaluate the revised load are given below.

1. The dynamic load f actor was evaluated based on the natural f requency of the component. In most cases the DLF used in the original design was the theoretical maximum.

The original design load (Psax x DLF) was compared to the revised impact load (revised Psax x DLF revised) and found acceptable if for the Radial Orientation, Porig/p ) 1.25 and if for the Circumferentiai Orientation, Porig/p ) 2 00.

2. For components other than structural beams originally qualified using a f orce tiu history evaluat ion, either mothud 1 'm use ! f or remnaluation or the force time history was redone using the teviacd load using radini M /A.

H

3. Components that were originally designed to a lower load were re-evaluated and qualified based on sufficient margin in the original design.

4. For structural beams originally qualified using a force time history evaluation, the force time history was recalculated using the Maise criteria.

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References 1.

General Electric Co., General Electric Standard Safety Analy i s s Report for

~ 238 Nuclear Island Design (CESSAR II), Volume 6/Arpendix 3B

~][~ 2. .

1 U.S. Nuclear Regulatory Commission,valuation NUREG-0978. 1983.

Appendix D),

3. C. Maise:

III Structures Close to the Pool," Department gy, ofr Nucle Brookhaven National Laboratory, Upton, N.Y. 11973 4.

February 15, 1984.

Program Load Evaluation and Acceptance 1978.

ant Criteria

, October 1~

5.

Scale Pool Swell Impact Testt:. General Electric August 1975.

. Co., " Mark ;

One-Third Test Series 5805," C.E. Report NEDE-13426P.

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