A36791, Forwards Response to NRC 990510 RAI Re GL 96-06 with Respect to Analysis of Water Hammer & two-phase Flow Issues. Supporting Calculation Also Encl

Forwards Response to NRC 990510 RAI Re GL 96-06 with Respect to Analysis of Water Hammer & two-phase Flow Issues. Supporting Calculation Also Encl

ML20196L086
Person / Time
Site:	Callaway
Issue date:	05/17/1999
From:	Passwater A UNION ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20196L091	List: A36791, Forwards Response to NRC 990510 RAI Re GL 96-06 with Respect to Analysis of Water Hammer & two-phase Flow Issues. Supporting Calculation Also Encl ML20196L096
References
GL-96-06, GL-96-6, TAC-MA36791, ULNRC-4033, NUDOCS 9905260065
Download: ML20196L086 (5)

Text

, .

union D2ctric One Ameren Plua 1901 Chouteau Avenue PO Box 66149 St. Louis, MO 631f46149 May 17,1998 - )

U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Station PI-137 Washington, DC 20555-0001 Gentlemen: ULNRC-4033 TAC No. MA 36791 fg DOCKET NUMBER 50-483 CALLAWAY PLANT

[N8[88 UNION ELECTRIC COMPANY

{ NRC GENERIC LETTER 96-06

References:

1) ULNRC-3483 dated October 30,1996

2) ULNRC-3526 dated January 27,1997

3) ULNRC-3667 dated October 17,1997

4) ULNRC-3826 dated May 1,1998

5) ULNRC-836 dated May 19,1998

6) NRC Request for AdditionalInformation dated May 10,1999 References 1 through 5 provided previous correspondence concerning NRC Generic Letter 96-06. In Reference 6 the Staff requested additional information with respect to the analysis of water hammer and two-phase flow issues. The requested information is provided in the attachments to this letter.

Please contact us ifyou have additional questions.

Sincerely, Alan C. Passwater Manager, Corporate Nuclear Services DS/jdg Attachments -

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,nl 9905260065 990517

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STATE OF-MISSOURI ).

) SS CITY OF ST. LOUIS')

Alan C. Passwater, of lawful age, being first duly sworn upon oath says that he is Manager, Corporate Nuclear Services for Union Electric Company; that he has read the foregoing document and knows the content thereof; that he has executed the same for and-on behalf of said company with full power and authority to do so; and that the facts

'therein' stated are true and correct to the best of his knowledge,.information and belief.

By Alan C. Passwater Menager, Corporate Nuclear Services SUBSCRIBM and sworn to before me this /7 Uk day of I ri a a , 1999.

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• N THOMAS J. BOKERN NOTARY PUBUC-STATE OF MISSOURI ST. LOUIS COUNTY MYCOMMISSION EXPIRES JULY 5,2000

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r cc: M. H. Fletcher Professional Nuclear Consulting, Inc.

19041 Raines Drive Derwood, MD 20855-2432 Regional Administrator U.S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive Suite 400 Arlington, TX 76011-8064 Senior Resident Inspector Callaway Resident Office U.S. Nuclear Regulatory Commission 8201 NRC Road Steedman, MO 65077 Mr. Mel Gray (2) VV[Q Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission 1 White Flint, North, Mail Stop 13E16 11555 Rockville Pike Rockville, MD 20852-2738 Manager, Electric Department Missouri Public Service Commission P.O. Box 360 Jefferson City, MO 65102 l

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Attachment 1 ULNRC-4033 Page 1 of 2 L NRC Ouestions Renardina GL 96-06

1. By letter dated October 17,1997,.UE provided to the NRC a copy of Altran Repon -

%225-TR-02. This report concluded that the column closure waterhammer that results from a loss of offsite power (LOOP) without a loss of coolant accident (LOCA) is the limited case. The Altran repon references "Callaway Waterhammer Load Calculation," 0096-020-CALC-01, Rev. O, dated June 29,1992, which predicts a pressure spike of 275 psig for this scenario. A copy of this document, or enough detailed information about the analysis methodology and assumptions that were used is requested.

Ressoase Union Electric contracted with ABB Impell in 1992 to evaluate water hammer data taken at Wolf Creek (during ESFAS testing), and to determine if this data could be used to

. bound the LOOP water hammer that Callaway would experience. ABB Impell, in the calculation referenced above (UE calculation number GN-17), modified the pressure vs.

time data from the Wolf Creek water hammer to account for differences in the test conditions and the Callaway design basis condition. For example, pressure is increased due to such factors as ESW design temperature is 95F whereas the test was conducted with~40F weter. The details of this analysis are included in the attached copy of calculation GN-17 (Impell Calculation 0096-020-CALC-01)

2. Except for a qualitative discussion and comparison of the energy (or impulse) transferred to the piping structure for the column closure and condensation induced water hammer, no information about the piping analysis for the hydro-dynamic loading was provided.

Resnonse The Altran report was transmitted to the NRC by Reference 3, and indicated that the ESW B Train would see a condensation induced water hammer that would increase stresses of the LOOP water hammer by no more than 26%. The A train would be increased by no more than 15%. As discussed below, increasing the water hammer loads by 26% does not result in exceeding allowable stresses for the system.

The stresses from the LOOP pipe stress analysis performed on the ESW system were divided into 4 sections. These are the A train supply, A train return, B train supply and B train return. The highest stress points as a result of the water hammer loading are shown below for each ponion of the ESW system. As described in the Altran report, the maximum increase in the water hammer load is 26% for the B train. For conservatism, the table below assumes this increase is also applicable to the A train (which the report ,

identifies with only a 15% increase).

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Attachment 1 l ULNRC-4033 Page 2 of 2

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The loads are combined in the table below as required by the FSAR table 3.9(B)-2 for Faulted conditions (PO + DW + DF), The table below also increases the Dead Weight and Water Hammer stress by 0.75i (es required by ASME). These values are compared to the Allowable stress specified in Table 3.9(B)-7 for these conditions. In all cases, the water hammer load due to LOOP with LOCA results in stresses below the allowable stress limits.

Stress Run Node with Pressure Dead Weight Water Hanuner SIF PO+ Allowable Max Stress Stress (PO) Stress (DW) Stress (DF) (i) 75i(DW+1.26DF) (2.4Sh)

A Train Supply 6003 1718 181 4704 2.94 15186 36000 A Train Return 6003 1718 455 5220 2.94 17224 36000 D Train Supply 6008 1324 1300 4684 2.61 15422 36000 B Train Return 6004 1324 242 7116 2.61 19349 36000 1

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Attachment 2 CALCUIrATION COVER PAGE l

Calc. No. $N"l7 '

. Rev. No. (M l Addenda No. d l Union Electric - UENE Computed By

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Title [evt 'a m u (c. hr Date 7!'l( 19 72.

her / 6eu d% [v n., Checked By M n c, .

Date 7/2t_ 19 9g Approved By h f MLc Safety-Related A.' Date 7 19 72__ I Nonsafety-Related Pages M Graded Program Scope RFR/ CMP NO. -

Objective b-<' T C> ec/ I l

Calculation Method / Assumptions l /

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Program Version Sources of Data / Equations

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l Conclusions V

'FOR INFORMATION ONLY Page 1 of 1 CA-#1489 02-26-92 EDP-ZZ-04023

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