PY-CEI-NRR-0351, Provides Further Info Re Pool Dynamic Loads (SER Open Item 9).Sufficient Design Margin Exists Between Original Design Basis Pressure & Impact Pressure as Calculated by Modified Methodology

Provides Further Info Re Pool Dynamic Loads (SER Open Item 9).Sufficient Design Margin Exists Between Original Design Basis Pressure & Impact Pressure as Calculated by Modified Methodology

ML20132D261
Person / Time
Site:	Perry
Issue date:	09/23/1985
From:	Edelman M CLEVELAND ELECTRIC ILLUMINATING CO.
To:	Youngblood B Office of Nuclear Reactor Regulation
References
PY-CEI-NRR-0351, PY-CEI-NRR-351, NUDOCS 8509300125
Download: ML20132D261 (4)

Text

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F THE CLEVELAND ELECTR P o. Box 5000 - CLEVELAND, OHlo 44101 - TELEPHONE (216) 672-9800 - ILLUMINATING BLDG - 55 PUBLIC SoUARE Serwng The Best Location in the Nation September 23, 1985 MURRAY R. EDELMAN PY-CEI/NRR-0351 L VICE PRESIDENT NUCLE A R Mr. B. J. Youngblood, Chief Licensing Branch No. 1 Division of Licensing U.S. Nuclear-Regulatory Commission 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 information pursuant to our letter dated September 13, 1985 regarding pool dynamic loads. Additional clarifications to Attachmet 3 of that letter are enclosed. In Attachment 4 to that letter, " Evaluation of Impact Loads ~on Short Stryctures Close to the

, Pool," we committed to demonstrate that suf ficient design margin exists between the original design babis pressure and the impact pressume catchlated using'the Modified Maise methodology. We have completed oug analysis an'd this letter serves as confirmation that, in all but ten cases where a static analysis with a dynamic load factor was used for the original design load, suitable margins were demonstrated which accomodate the staff's concerns with respect to the conservatism in the Modified Maise methodology. Suitable margins were found for components if a 25% margin was demonstrated for the radial orientation and 100% margin for the circumferential orientation. For those ten components which did not demonstrate the suitable margins a reevaluation is being performed to demonstrate the design is sufficient to accomodate the higher loads. The reevaluation uses radial hydrodynamic mass to calculate the maximum pressure and the versed sine curve to determine the dynamic load factor. This reevaluation will be completed by September 30, 1985. Based on discussions with the staff on September 17, 1985, the information in this letter should enable SER Open Item (9) to be resolved.

If you have any questions, please let me know.

Very truly yours, 8509300125 850923

]h Murray-R. Edelman

• h

{DR ADOCK O j 40 Vice President Nuclear Group MRE:nje \

o cc: Jay Silbergg Esq.  ;)

John Stefano (2)

J. Grobe

a 3B.6 CONTAINMENT No deviations.

3B.6.1 CONTAINMENT LOADS DURING A LARCE STEAMLINE BREAK (DBA)

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

33.6.1.1 Compressive Wave Loading No deviations.

3B.6.1.2 Water Jet Loads No deviations.

3B.6.1.3 Initial Bubble Pressure No deviations.

3B.6.L.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.

"W 3B.6 1.6 Containment- Load Due to Pool' Swell"at the HCU FI N D Wetwell

- Pressurization) '

t .

' The PNPP. containment wall design for loads due.to'?,poolf swell at thefHCU; floor bounds that of GESSAR'It (11 psid). In dddition, the Perry HCU floor,' -

is approximatel'y 27 f5et above the suppression pool surface and has been '

designed for 10 psid across the total area of the platform (structural steel

( plus grating). This was reduced from the GESSAR specification due to the Perry HCU floor being 7 feet higher than the GESSAR standard. In addition, n plant unique analysis showed a pe ik calculated pressure dif ferential equal to approximately 5.4 psid based upon a des.ign open area ratio of 30 percent of the total HCU floor area, (Ref s. 2, 3 & 4). GESSAR Figure 3B-58 is not applicable to Perry.

3B.6.1.7 Fallback Loads No deviations.

3B.6.1.8 Post Pool-Swell Waves No deviations.

3B.6.1.9 Condensation oscillation Loads GESSAR Figure 3B-17 is not' applicable to Perry. See FSAR Figure 3B-6 for condensation oscillation loads on containment.

38.6.1.10 Chunging No deviations.

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l l 38-5 e+- ,y-mwem- wm --n-=a -+

e p--4+=+-=9-'----Pt:w==+-- - - +;e-*---M9p--y -Twv' 79- - - ---'rm wwy-Tw-wrvWW-'

t-*' *w ,,e -e-p 1-e yein-,-

.- n 3B.8.1.4 Condensation Loads LOCA condensation-oscillation drag loads are bounded by the PNPP LOCA bubble pressure drag load methodology for piping, or these loads are bounded by the SRV second pop for the strainers. For the columns, condensation-oscillation was included in the original design. (Reference 5) 3B.8.1.5 Chugging Chugging drag loads are bounded by the PNPP LOCA bubble pressure drag load methodology for piping, or these loads are bounded by the SRV second pop for the strainers. For the columns, chugging was included in the original design.

(Reference 5 & 6) 3B8.1.6 Compressive Wave Loading No deviations.

3B.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 'NPP load methodology and the GESSAR II load methodology is given in Section 3BL.3.2. of.the FSAR.

3B.9 LOADS ON STRUCTURES AT THE POOL SURFACE As required by the NRC Draf t Acceptance Criteria, dhe Perry analysis used a velocity ranging from zero fps at the pool surface to a ma.ximum of 50 fps as a function'of height; 4nstead of the constant 40' fps'yclocitp 'specified in GESSAR

~

Table 3B-2, to calculate pool swell drag loads. - .

3B.10 LOADS ON STRUCTURE BETWEEN THE POOL SURFACE AFD THE HCU FLOORS No Deviations.

33.10.1 IMPACT LOADS Impact loads are calculated in accordance with CESSAR as modified by the requirements of the NRC Draft 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 & 6) 3B.10.2 DRAG LOADS Drag loads are calculated in accordance with CESSAR as modified by the requirements of the NRC Draft Acceptance Criteria. Figure 3B-75 is not used with abscissa values less than unity.

3B-7

3B.10.3 FALLBACK LOADS No deviations.

3B.11 LOADS ON EXPANSIVE STRUCTURES AT THE HCU FLOOR ELEVATION.

The loads on the PNPP HCU floor-are discussed in Section 3B.6.1.6. The only other expansive structure in Perry in the pool swell region is the steam tunnel, which is designed in accordance with the NRC Draft Acceptance Criteria.

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

3B.13 REFERENCES No deviations. Additional PNPP specific references as follows:

1. Draft NRC Accepance 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, GE, dated October 8, 1982.

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

3. CEIletter,PY-CEI/NRS-0055L'frhm'MsRUfdktiAY 'A N.J. Youngblood, NRC, dated June.-20,N 963. - Dif'#N *^ ~ .. _.

,A 45

4. CEI letter, PY-CEI/NRR-0113L ffom M. R. Edelman, CE}yTe[ fig.,,

8.'la youngblood, NRC, dated July 11, 1984. *1eIL/f 5 CEI letter, PY-CEI/NRR-0235L from M. R. Edelman, CEI to B. J. Youngblood, NRC, dated May 16, 1985.

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

3B-8