SNRC-1583, Forwards Supplemental Info Re Temp Profile Inside Primary Containment Used for Environ Qualification

Forwards Supplemental Info Re Temp Profile Inside Primary Containment Used for Environ Qualification

ML20244C670
Person / Time
Site:	Shoreham File:Long Island Lighting Company icon.png
Issue date:	04/12/1989
From:	Leonard J LONG ISLAND LIGHTING CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
SNRC-1583, NUDOCS 8904200330
Download: ML20244C670 (7)

Text

- _ _ - . - _ .

8

[Mj@ LONG ISLAND LIGHTING COM PANY SHOREHAM NUCLEAR POWER STATION P.O. BOX 610, NORTH COUNTRY ROAD . WADING RIVER, N.Y.11792 JOHN D. LEON ARD, JR.

VICE PRESIDENT NUCLEAR OPERATIONS SNRC-1583 APR 121989 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Temperature Profile Inside Primary Containment Used For Environmental Qualification Shoreham Nuclear Power Station - Unit 1 Docket No. 50-322

Reference:

1. LILCO (J.D. Leonard, Jr.) Letter SNRC-1578 dated April 4, 1989 to NRC (Document Control Desk) same subject.

2. USNRC Memorandum from W.V. Johnston to T.M. Novak dated 12/29/82 entitled " Supplement to Safety Evaluation Report for Shoreham Nuclear Power Station Unit 1."

Gentlemen:

This letter supplements the information provided in the referenced letter and provides the results of a recent engineering evaluation which developed a modified environmental qualification (EQ) temperature profile (Figure A). The modified EQ profile shows the temperature remains at 170*F from 4 to 18 days, 160*F from 18 to 35 days, and 150*F for the remainder 180 days. The evaluation was performed to determine the affect of this elevated temperature condition on the qualified post accident operating time of the equipment and is discussed in i

detail below. As can be seen in Figure A, the modified EQ temperature profile bounds'the worst case primary containment I (drywell) composite temperature profile, which is the conservative combination of the primary containment temperature l response to a main steam line break (MSLB) and a loss of coolant accident with no containment spray, at all times. Thus, LILCO submits that this fact, supported by the following details of the engineering evaluation, resolves the issues described in Section 12.5 of the Operational Readiness Assessment Inspection Report 50-322/89-80.

e9o42co3ao 890412 p DR

~

ADOCK 05o00322 \

u_______.__ PDC \

SNRC-1583 j Page 2 Essential Elements of the Engineering Evaluation The evaluation consisted of the following:

(a) The EQ equipment list was reviewed to identify each Environmental Qualification Documentation Package (EQDP) which qualified equipment installed in the drywell.

Thus the scope of the evaluation was established.

(b) For each equipment type, the basis for the qualified operating time was examined. For some EQDPs, the equipment was found to be qualified without the need for additional analysis.

(c) For the EQDPs requiring reanalysis, the modified EQ profile (from 4 to 35 days) was used to determine the effect on the qualified operating time. In essence, this calculation determines the amount of aging experienced by a device due to exposure to both the medified EQ and test profiles so that it can be coupared. In all cases, the test subjected the device to harsher accident aging than the modified EQ profile and the equipment was still qualified for the required operating time, with margin.

In summary, all equipment was shown to be qualified for the modified EQ temperature profile for its required post accident operating time. Attachment I to this letter provides additional information concerning the evolution of the modified EQ temperature profile. Details on the use of the Arrhenius methodology are provided in Attachment II. Should you have any additional questions please do not hesitate to call my office.

Very truly yours, e]

W)a & .

J. D. Leona , .

Vice President - Nuclear Operations GJG/ap Attachment cc: W. Russell S. Brown F. Crescenzo

)

)

1 Attachment I l SNRC-1583 Page 1 of 2  ;

EDIFIED BQ '5MPERNEURE PROFIIE ETR 'mE PRDERY CONMIIGENT DRDGELL SiORERAM NUCumR PONER SBTI(M ]

J I. INBm;nON A nodified equipnent qualification temperature profile for the drywell has been conservatively established and verified against actual test data. j The modification of the EQ temperature profile for the drywell is based on l a consideration of the most liraiting spectrum of design basis accidents.  !

The nodified W profile as shown in Figure A conservatively bounds steam line break and LOCA design basis accidents. Ioss of coolant accidents which daninate the long term drywell tanperature response were evaluated conservatively with containment sprays and wi.thout containment sprays.

Use of the no containment spray case for this purpose is considered to be 1 conservative. j II. IJMITING ACCIDENTS

'Ihe Design Basis Accident for the drywell atmospheric temperature of the Shoreham Nuclear Power Station is identified in the USAR as'a small steam line break; the con 64-nt peak temperature occurs in less than 300 seconds into an accident. 'Ibe drywell long term temperature response is controlled by the containment heat sinks and the RHR heat exchanger capacity. h long term temperature response is typically shown by a double ended rupture of a recirculation suction line (IOCA) as described in section 6.2.13 and shown in Figures 6.2.1-33 and i,2.1-13 of the USAR.

The accident scenario for the recjxculation suction line break is described in the USAR Table 6.2.1-2. The Core Spray system starts to deliver flow fran the suppression pool to the reactor vessel at 30 seconds after the accident. Iow Pressure Coolant Injection (fPCI) of the suppression pool water into the reactor is initiated u about 45 seconds into the accident. Case C assumes that at about 600 seconds the  !

Containment Spray cooling mode is initiated. Case D assumes that no Containment Spray is actuated.

III. ENVIROINENTAL QUALIFICATION MODIFIED PROFILE The modified EQ temperature profile for which the equipnent inside the drywell is qualified is obtained from a couposite diagram for the short term small steamline break (USAR Figure 6.2.1-33) and the long term Case D (USAR Figure 6.2.1-13). The enveloping curve is shown by dashed lines in s Figure A (attached) . 'Ihe EQR temperature profile (Figure D-1 of the MR) did not envelope the accident profile (Case D only) at all times. The ,

modified EQ temperature profile shown in Figure A (attached) corrects for this. This Figure A will replace the information given in Figure D-1 in the EQR.

1

Attachnent I SNRC-1583 Page 2-of 2 IV. SLM%RY CONCWSION A decision was made to review and evaluate qualification of the equipnent in the drywell to the modified EQ profile. Case D of the USAR Figure

-6.2.1-13 was selected as the most upper bound drywell temperature response to a loss of coolant accident, because it does not take credit for.

operator action to initiate containment sprays following a I KA.

Attachment II SNRC-1583 Page 1 of 2 USE OF ARRHENIUS ymnnrunry For the majority of SNPS equignent, the test demonstrated operating time was shorter then the required operating time. In order to establish qualification for 180 days, the testing was supp1mented by Arrhenius analysis to dmonstrate qualification for the equipnent's operatino time. The Arrhenius methodology was conservatively applied since no credit was taken for any portion of the test profile which enveloped the transient portion of the accident profile.

The Arrhenius equation is used to determine the amount of aging experienced by the device during testing and the amount of aging the device will experience due to exposure to the nodified EQ Profile for the equipnent's required operating tim. The results are then cmpared. If the test conditions subjected the device to greater aging degradation than expected in the plant, the test is considered more harsh and the device considered qualified.

For the purpose of this study, the transient portion of the profile is considered to be the first day and the Arrhenius calculations performed for operating time specifically excluded this first day of date. Qualification for at least the first day of the event has been established by type test alone.

Arrhenius techniques have been applied only to those portions of the profile after the first day.

Conditions after the first day are not considered traraient. After the first day, the containment begins its steady cooldown phase, with the modified EQ profile remaining conservatively at 200 F for 3 days ,170'F for 14 days,160'F for 17 days, and 150'F for 145 days. Over this period (fr m 1 day to 180 days), the urnperature varies slowly whereas, during the first day, the conditions vary greatly. Thus the 1 to 180 day duration is not considered to I

be a transient condition.

The following additional conservatism exist in the analysis: .

1 a) The step function modified EQ profile used in the analysis is more conservative than the accident profile. For exa io, in the period frm 1 day to 4 days after accident initiation, the actual plant t m perature slowly recedes frm approximately 185 F to 170'F ( a 15 F change in three days) but is approximated by a constant temperature of 200'F.

b) Selection of the test data to be input to the calculations was taken frm the "back end" of the profiles and used only that portion of the profiles necessary to verify qualification with margin. This allows for I qualification to be based, as much as possible, on actual type test and l minimized the amount of qualification based on type test supplemented by analysis, c) In arne cases, the analysis assumed that the modified EQ profile reained at a specific plateau for the remainder of the accident. For example, the period frm 4 days to 180 days might have been assumed to remain at 170 F for the purpose of the calculation rather than dropping to 160'F.

. ,y Attachment II SNHC-1583 Page 2.of 2 d) - The margin in operating time desnanstrated by these analyses was far in excess of the 10% r e nded by-IEEE 323-1974, and in some cases on the order of hundreds of percent. In addition, SNPS has conservatively assumed a required operating time of 180 days though 100 days is technically:

defensible and known to be generally accepted by the NBC, e) After the first day, the test and modified EQ profiles are not transient and are'relatively close in temperature. Therefore, the aging effects should be relatively parallel for both cases and the Arrhenius equation will accurately predict material. degradation.

Qualification of the GE 200 Series electrical penetrations was performed in a special analysis which has been'specifically reviewed and accepted by the NRC as stated in USNBC Memorandum from W.V. Johnston to T.M. Novak,' dated 12/29/82 entitled " SUPPLEMENT TO SAFETY EVALIPTION REPORP FOR SHOREHAM NUCLEAR POWER STATION UNIT 1." The analysis presented ard accepted for this equipnent, which previously used Arrhenius methodology for the first day, has been revised to incorporate the modified profile with no effect on its qualification' status.

In summary, all' equipnent was shown to be qualified for the revised drywell taperature profile for its required post-accident operating time.

I l

~ ... .- -

u s .'

' R a

.$ o 'N-"

"_O s ,

g . . ,

c M *  ;

, g g m O

w R a O

• g  : aw

.g *

• O U

m  : 0 a% -

l * .- -*

b - -

'N. c s  ; E G

gt C o

[ h>

M gg l M 4

4 1

+

g N

H

,n O  :

C A << . t.

.s ,s -

g B 9 N-- , . , - ***+ f o g g,

g. , -

~ m J '

g .b b .

• w 6 '~g C ,t' Up

2 -

o I aR s, m a i 1

Nm m -

+

• g 5

^R  :

l 1

m @4Y / /5g N i 6f > N ~

~

y

$z /

e / o g o ) J a i-g M f @ _

e: /  : S m

4

'.I '\ b- -

. I

.- s 5d~

va g z

Y- \[ f Cm Ch D i y 0 a  ; i ~

b- CE I  : i 4

- __ p! )' . . . ,sc Y, g g HL  : W o

?a-

% dm  : H u N - u.

~ *

'/ k h i .

E "o W 2:

E s

_~ ~

s N 2  :

'o m .

r

~

'o

~

5 w -  :

'o -

ho

\

OS3 003 OSI 001 09 OSE 00E 3 030 '3801083dW31 1 '

- _ _ _ _ _ _ _ _ _ _ _