ML20050C823

Forwards Addl Info in Response to 820225 Request Re Peak Containment Temps for Equipment Qualification.Small Steam Line Break Analysis Peak Drywell Temps Lower than FSAR DBA Temps

ML20050C823
Person / Time
Site:	Hatch
Issue date:	04/05/1982
From:	Beckham J GEORGIA POWER CO.
To:	Stolz J Office of Nuclear Reactor Regulation
References
TAC-42505, TAC-42506, NUDOCS 8204090384
Download: ML20050C823 (4)

Text

c. w r. m t v,

't { f i e f ie,

g a c.

o 4

?

a 2ee m

i <

I.NJ";,(,.

L Georgia Power

~

I.

April 5, 1982 n,

a. e,.-

hh O

iiEChsVED APR 8,1982>

2 U. S. Nuclear Regulatory Commission 1

Operating Reactor Branch #4 Division of Licensing ga mann a Washington, D. C.

20555 M

ATTENTION:

Mr. John F. Stolz NRC DOCKETS 50-321, 50-366 OPERcTING LICENSES DPR-57, NPF-3 EDWIN I. HATCH NUCLEAR PLANT UNITS 1, 2 RESPONSE TO CONTAINtENT SYSTEMS BRANCH REQUEST FOR ADDIT 10NAL INFORMATION ON MAIN STEAM LINE BREAK Gentlemen:

The following is submitted in response to your letter of February 25, 1982 which requested additional information regarding peak containment temperatures for equipment qualification purposes at Plant Hatch.

The letter requested Georgia Power Lompany (GPC) to perform and submit main steam line break analyses for multiple break sizes since the NRC staff had determined that this type of accident was limiting for peak containment temperatures.

A small line break (SLB) analysis in high energy piping for Plant Hatch was performed.

Based upon the results of this analysis, we conclude that the design basis accident (DBA) analyses in the FSARs bound the SLB analysis with regard to dIywell peak temperature.

The Plant Hatch unique drywell temperature SLB analysis examined a 2

spectrum of three break sizes (.01, 0.1, 0.5 ft ) in hi h energy lines to determine the maximum drywell temperature.

The 0.5 ft break results in rapid vessel depressurization and produces the highest drywell peak temperature of the three break sizes, which is 2740F.

The GE SLB analysis was performed in compliance with NUREG-0588 (except for the manner in which heat sink condensate is treated and the assumption of a homogeneous air / steam mixture in the drywell).

The assumptions made during the course of the analysis are summarized in Attachment 2.

8204090384 820405 1

DR ADOCK 05000321 hI PDR

GeorgiaPower d U. S. Nuclear Regulatory Commission Operating Reactor Branch #4 Division of Licensing Washington, D. C.

20555 April 5, 1982 Page Two The drywell peak temperatures obtained by the DBA analyses in the HNP-FSARs for Units 1 and 2 are conservative and the assumptions documented tr/ GE have been approved by the NRC (NUREG-0661).

As shown in Attachment 1, the peak drywell temperature for each SLB case is lower than the FSAR DBA temperaturer, of 2890F for Unit 1 anci 3040F for Unit 2.

This confirms that the original drywell temperature analyses contained in the HBP-FSARs are boundir.g for peak temperatures for equipment qualification purposes.

J. T. Beckham, Jr. states that he is Vice President of Georgia Power Company and is authorized to execute this oath on behalf of Georgia Power Company, and that to the best of his knowledge and belief the facts set forth in this letter are true.

GEORGIA POWER C0hPANY By :

O h

gJ.T.Beckham,Jf.

Sworn to and subscribed b ore me this 5th day of April, 1982 A

m L_

/

y)

")

$ta ublic

'**. suk e CS/mb u

Enclosures xc:

M. Manry R. F. Rogers, III J. P. O'Reilly (NRC-Region II)

ATTACFf4Et4T 1

SUMMARY

OF SLB VERSUS DBA ANALYSIS RESULTS Break Size Time to Maximum Temperature Maximum Temperature 2

(ft )

(sec)

( F)

.01 676 213.4

.1 623 262.6

.5 7.7 274.3 ff1P-2 FSAR-DBA Approx. 8 304.0 HtP-1 FSAR-0BA Approx. 8 289.0

Y 3

ATTAC}fENT 2

- MAJOR IPFor SLB ANALYSIS ASSUMPTIONS Scram:

At time zero MSIV Closure:

At 3.5 seconds ECCS Systems:

HPCI plus 1 core spray purap Feedwater flow:

Coastdown to zero in 7 sec.

Auto depressurization System:

Actuated at 10 min.

RHR pool cooling:

1 loop initiated at_10 min.

U Initial suppression pool temp:

95 F Initial reactor. power:

102% of rated Initial drywell relative hunidity:

20%

Initial dq/well temperature:

135 F Drywell steel liner:

2 Surface area:

15842 ft Heat capacity 90108 BTU / F 4

1 4

4 e

i i

I l

.. ~. - -. - - -..

---

}