ML20002E388

Application to Amend License DPR-77,removing Independent Essential Raw Cooling Water Sys Trains Required by Tech Spec 3.7.4.Reasons & Justifications for Amend Encl

ML20002E388
Person / Time
Site:	Sequoyah
Issue date:	01/19/1981
From:	Cross J TENNESSEE VALLEY AUTHORITY
To:	Schwencer A Office of Nuclear Reactor Regulation
References
NUDOCS 8101270702
Download: ML20002E388 (4)

Text

n

'*g g

TENNESSEE VALLEY AUTHORITY h

CHATTANOOGA. TENNESSEE 37401

c. 3 UT; I

<[ ^

500A chestnut Street Tower II go FG i~

January 19, 1981

~

Q E

s O

Director of Nuclear Reactor Regulation Attentions Mr. A. Schwencer, Chier Licensing Branch No. 2 Division of Licenaing U.S. Nuclear Regulatory Commission Washington, DC 20555 Dear Mr. Schwencer In the Matter of

)

Docket No. 50-327 Tennessee Valley Authority

)

I In accordance with the provisions of 10 CFR 50.59, we have determined that the Essential Raw Cooling Water System configuration required to allow modifications to Component Cooling Water Heat Exchanger C constitutes an unreviewed safety question. Therefore, we mquest an amendment to license DPR-77 to allow completion of the proposed modification for Sequoyah Nuclear Plant unit 1.

1 Enclosed are 41 copies of the following information.

(1) The proposed amendment to license DPR-77 (2) TVA's justification for the modification In accordance with requirements of 10 CFR 170.22, we have determined the proposed amendment to be Class III. This classifiestion is based on our belief that no significant hazards consideration is invoked. The remit-tance of $4000 is being wind to the Nuclear Regulatory Commission, Attc'Aon Licensing Fee Management Branch.

Very truly yours, TENNESSEE VALLEY AUTHORITY i

fY J. L. Cross Executive Assistant to the Manager of Power Sworn d subsorfbed before me thi day of WLm, 1981 l

k L

liotary Publia r

My Commission Expires

/

Enclosums (41) 8101270 70 2

^ " ' " ' " " ' ' " " ' ' " ' * * ' " * '

a ENCLOSURE 1 SEQUOYAH NUCLEAR PLANT UNIT 1 PROPOSED LICENSE AMENDMENT In order to complete modifications of Component Cooling Water Heat Exchanger C, we request that the following paragraph be added to license DPR-77.

Before unit 2 operation (unit 2 in either mode 1, 2, 3, or 4), TVA shall be allowed to operate unit 1 with 2A and 1B ERCW headers tied together (thi.s removes the independent trains of ERCW as required by Technical.Specifica-tion 3.7.4.1).

This change shall be allowed for a period of eight weeks while performing modifications to Component Cooling Water Heat Exchanger C.

e.-es----ew%..m-.-.4a

-r

_mw s---

p%%T_>

4.

!~

1 4

1 J

ENCLOSURE 2 1

REASONS AND JUSTIFICATIONS FOR CHANGES.TO SEQUOYAH NUCLEAR PLANT UNIT 1 GPERATING LICENSE DPR-77

.. + - - - - - _.... -

._+.. _ _ _,u_

J s

e i

l' J-r.

h 1

i-s l

I' i

}".

I 4

h l

zr -

J

'> uh -

}s gg

,~w

.. 9 a-__q-wy__p,.-,..

p.,,-

y

..w,-

.,w...

--,w7,,,,,

y-.e-w-~e

, e JUSTIFICATION FOR PROPOSED LICENSE Reason Change Required Component Cooling System (CCS) Heat Exchanger C is to have its tubes staked to provide stability of the tubes during heat exchanger design flow conditions. The repair work is required to be completed before two-unit operation.

In order to guarantee a fully redundant and qualified CCS, CCS Heat Exchanger B must ba substituted for Heat Exchanger C, and Essential Raw Cooling Water (ERCW) headers 1B and 2A must be tied together. The reduction in ERCW header independence constitutes a loss of independence as required by Technical Specification 3.7.4.1.

Safety Evaluation Postulated design basis ERCW pipe breaks'are limited to "through wall leakage cracks." Six hours of auxiliary building sump capacity are avail-able before filling the sump which allows ample time to isolate the faulty header without having to shut the header down. Large breaks are not postulated.

~ Sufficient Asolation capability exits for CCS Heat Exchanger A to be isolated from ERCW header 1B in the event that train A power is lost. The inlet valve to Heat Exchanger A is a motor-operated valve powered from train B.

Upon loss of train B power, a train A valve automatically closes to isolate ERCW header 2A from ERCW header 1B.

The CCS and ERCW System are described in section 9.2 of the Sequoyah Final Safety Analysis Report.

me n

w