ML20011F623

Application for Amends to Licenses NPF-4 & NPF-7,revising Analysis for Rupture of Main Steam Pipe by Eliminating Low Pressurizer Safety Injection

ML20011F623
Person / Time
Site:	North Anna
Issue date:	02/26/1990
From:	VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML20011F620	List: ML20011F619 ML20011F622 ML20011F623
References
NUDOCS 9003070051
Download: ML20011F623 (6)

Text

. . - . . .- - . . . . .

.f 4

.. a 6

Attachment 2 i q

4 A

Proposed Operating License Admendment i North Anna Unit 1 I

Virginia Electric and Power Company

[ BRA 88M8888lgge h

• i

p

. 7-F. The design of the reactor coolant pump and steam generator supports may be revised in accordance with the licensee's submittal dated November 6,1986 (Serial No. 86 477A).

G. The ar.alysis for rupture of a main steam pipe may be revised in l accordance with the licensee's submittal dated (Serial No. 90 046). ;

H. This amended license is effective as of the date of issuance and sha!l

' i L expire at midnight on April 1,2018. i u

FOR THE NUCLEAR REGULATORY COMMISSION Originally Signed by R.C. DeYoung for Roger S. Boyd, Director Division of Project Management  :

Office of Nuclear Reactor Regulation l

- Attachments:

1. Construction Related items to be completed prior to Initial Criticality

2. Appendices A and B Technical Specification page changes

3. Figure 1

4. Table 1 Date of Issuance: APR 11978 u

L l

l

, , .. l

. o: ,

. Attachment 3 i

i p

4 Proposed Operating License Admendment ,

North Anna Unit 2  !

i i

k l

[

L 4

b k -

Virginia Electric and Power Company t

l,,, 9 l.

i

l. The analysis for rupture of a main steam pipe may be revised in accordance with the licensee's submittal dated (Serial No.90-046).

J. This amended license is effective as of the date of issuance and shall expire at midnight on April 1,2018.

FOR THE NUCLEAR REGULATORY COMMISSION

/

Originally Signed by Harold R. Denton Harold R. Denton, Director Office of Nuclear Reactor Regulation

Attachment:

Appendices A & B Date of Issuance: AUG 211980 4

l l

l 1

- - - , + -

t

, i

g. .. ,

1 i

1

,- Attachment 4 1

l J

1 1

J 1

'l y

1 1

i Significant Hazards Determination i

L h

i  :

P i

1.

l-l' Virginia Electric and Power Company -

L

->.__________1__________

t o  !

i i .[

SignificanLMazarda latenninailon The proposed change to revise the rupture of a main steam pipe analysis by l eliminating the low low pressurizer safety injection initiating function does not result in a significant hazards consideration per 10 CFR 50.92. -

1. The proposed change does not significantly increase the probability of  ;

occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report. The elimination of the low low pressurizer pressure safety injection initiating function  :

is only for purposes of analysis, with regard to the rupture of a main steam pipe. '

i No physical changes or modifications are being made to the plant of its equipment. Thus, there is no change in the probability of occurrence of any  :

accident, including rupture of a steam pipe.

The current analysis for rupture of a steam pipe assumes that low low pressurizer pressure safety injection is available. For certain small steam line .

break scenarios, safety injection was initiated based on pressurizer pressure. If the pressurizer pressure safety injection is not available, the consequences of a  :

small steam line break could increase.

An analysis was performed to evaluate small steam line break censequences, without the benefit of low pressurizer pressure safety injection. Our analysis concludes that the applicable accident analysis acceptance criteria are met for the entire spectrum of steam line break sizes, without relying on low low pressurizer pressure safety injection. The large (hypothetical) steam line break remains the limiting steam line rupture case. Accordingly, we conclude that the consequences of a main steam pipe rupture are not increased and that low L pressurizer pressure safety injection is not necessary for a rupture of a main steam pipe. Because the low pressurizer pressure safety injection is not ,

necessary for rupture of a main steam pipe, there is no increase in the '

consequences of a malfunction of the associated equipment.

2. The proposed amendment will not create the possibility of a new or different kind of accident from any accident previously evaluated. A steam line break accident is cur.rently a design basis accident. The only difference is the l

initiating event. However, the large (hypothetical) steam line break remains the limiting steam line rupture case. As noted above, no physical changes or modifications are being made to the plant or its equipment. The only change is to eliminate the low pressurizer pressure safety injection initiating function for j the rupture of a main steam pipe analysis. )

3. The proposed amendment does not involve a significant reduction in a margin

of safety. As previously stated, our analysis shows that the applicable accident I analysis criteria are met for the entire spectrum of steam line break sizes. In addition, the large (hypothetical) steam line break remains the limiting steam '

l line rupture cace.

. - -_