ML20098E961

Proposed Tech Specs,Changing Surveillance Requirements Re Steam Generator Blowdown Valves (Table 3.6-2)

ML20098E961
Person / Time
Site:	McGuire, Mcguire
Issue date:	09/28/1984
From:	DUKE POWER CO.
To:
Shared Package
ML20098E957	List: ML20098E956 ML20098E961
References
TAC-55970, TAC-55971, NUDOCS 8410020181
Download: ML20098E961 (4)

Text

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TABLE 3.6-2 y

CONTAINMENT ISOLATION VALVES-2

^S MAXIMUM ISOLATION e.

VALVE NUMBER FUNCTION TIME-(SEC) eh 1.

Phase "A" Isolation i

-m, BB-1B#

_ Steam Generator A Blowdown Containment Outside Isolation

<10 I

s BB-28#

t Steam Generator B Blowdown Containment Outside. Isolation 210

~ 5.

.BB-3B#

/'

M Steam Generator C Blowdown Cantainment Outside Isolation 210 BB-4B#

f ro 4

Steam Generator D Blowdown Containment Outside Isolation 710 BB-5A#

Steam Generator A Blowdown Containment Inside Isolation 710 BB-6A#

Steam Generator B Blowdown Containment Inside Isolation 210 BB-7A#

Steam Generator C Blowdown Containment Inside Isolation 210 BB-8A#>

Steam Generator D Blowdown Containment Inside Isolation 710 4

N*

CF-26AB#

Steam Generator D Feedwater Containment Isolation

<5

?

CF-28AB#.

Steam Generator C Feedwater Containment Isolation 75 i

CF-30AB#

Steam Generator B Feedwater Containment Isolation 75 CF-35AB#

Steam Generator A Feedwater Containment Isolation 15 i

CF-126B Steam Generator'A Main Feedwater to Auxiliary Feedwater

$10 Nozzle Isolation CF-1278 Steam Generator B Main Feedwater to Auxiliary Feedwater 110

- Nozzle Isolation 4

- CF-1288 Steam Generator C Main Feedwater to Auxiliary Feedwater 110 Nozzle Isolation l

CF-1298 Steam Generator, D Main Feedwater to Auxiliary Feedwater 110 j

. Nozzle Isolation CF-134A Steam Generator A Feedwater Containment Isolation Bypass 110 CF-135A' Steam Generator B Feedwater Containment Isolation Bypass

$10 CF-136A Steam Generator C Feedwater Containment Isolation Bypass 110 i

CF-137A Steam Generator D Feedwater Containment Isolation Bypass

$10 i

CF-151A Auxiliary Nozzle Temper SG A

<10 4

1 t

8410020181 840928

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PDR ADOCK 05000369 p

PDR i

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L J6stification and Safety Evaluation The proposed amendmenta would involve revising Technical Specification Table-3.6-2, containment Isolation Valves, by deleting from the list fourSteam Generator Blowdown Valves (BB140, BB141, BB142, BB143). These valves do not perform containment isolation functions and are no longer considered containment isolation valves, therefore they should be deleted from the list of containment isolation valves.

The purpose of the Steam Generator Blowdown Recycle System (BB) is to maintain acceptable steam generator shell side chemistry and to conserve the blowdown water through recycling. Each steam generator has one BB

-line exiting the containment, resulting in four containment penetrations for each unit. Each of these containment penetrations has containment isolation capability provided by valves bbl through BB4 on the Auxiliary Building side and valves BB5 through BB8 on the Containment Building side (see Figure 1). These valves are included in the leak test program as described in 10CFR Part 50 Appendix J.

Steam generator blowdown valves BB140 through BB143 were installed to permit pipe class changes from B to F, which were necessary to accomodate non-safety related BB subcooling heat exchangers. These valves were originally included on the Containment Isolation Valve list due to the valves preventing release of containment atmosphere through a potentially unisolated main steam isolation valve. However, due to design changes and modifications, this situation no longer exists. The determination-has_been made that the four steam generator blowdown valves (BB140, BB141, BB14? and BB143) are not required to perform containment isolation functions. Therefore, upon completion of a pipe class upgrade from F to B, the four valves will no longer be required to be tested as described in the Technical Specifications. Based on this evaluation, it is concluded that the proposed amendments would-not have any adverse impact upon public health and safety.

l FIGURE 1 Steam Generator Blowdown System (BB)

( Typical of Each Line.)

Before Modification BB140 Containment Auxiliary Building B85 BB1 S.G.

i o

ap zm as Pipe Class

]

Designation 4

I I

j After'Modificati5n Containment.

Auxiliary Building BB5 BB1 3

S. G.

i V

aE FeB 4

'?s l

n l-

$s

,4 Analysis of Significant Hazards Consideration As required by 10CFR50.91, this analysis is provided concerning whether the proposed

. changes to the technical specifications involve significant hazards considerations, as ' defined by 10CFR50.92.

The steam generator blowdown valves were originally installed to accommodate Steam Generator Blowdown Recycle System subcooling heat exchangers. The valves were required to prevent releases of containment atmosphere through a potentially un-

-isolated Main Steam Isolation Valve.

Recently, the heat exchangers were removed, therefore the steam generator blowdown valves are no longer needed. Upon removal of these valves the pressure boundary will extend from the Steam Generators to.

the containment isolation valves, thus containment isolation will be maintained.

It has been determined that the proposed changes to the Steam Generator Blowdown Recycle System would not:

1) Involve a significant increase in the probability or consequences of an accident previously evaluated; or

2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or

3) Involve a significant reduction in a margin of safety.

Based upon the preceding analysis, Duke Power Company concludes that the pro-posed amendments do not involve a significant. hazards consideration.

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