ML20209B140

Submits Addl Info in Support of Tech Spec Change Request 130 to License DPR-66,revising Table 3.6-7 Re Containment Isolation Valve Penetrations 87 & 88,per GDC 56

ML20209B140
Person / Time
Site:	Beaver Valley
Issue date:	04/16/1987
From:	Sieber J DUQUESNE LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
NUDOCS 8704280370
Download: ML20209B140 (8)

Text

.

F b des

'A@

Telephone (412) 393-6000 Nuclear Group

$pYgport, PA 15077-0004 April 16, 1987

,JT. S . Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

Reference:

Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Additional Information Supporting TSCR 130 Gentlemen:

On August 22, 1986, we submitted Technical Specification Change Request No. 130 (TSCR-130) which proposed a revision to the containment isolation valves listed on Table 3.6-1, penetrations 87 and 88. During our fifth refueling outage, modifications were made to the hydrogen recombiners which resulted in difficulty in meeting the required system flows when the containment was at subatmospheric pressure. In order to achieve the required flows, valve and line modifications were performed which included removal of the internals of the inside containment isolation valve, a weighted swing check valve, and the addition of a second outside containment isolation valve, identical to the existing outside isolation valve, a manually operated ball valve. This configuration resulted in containment isolation being provided by two outside containment manually operated ball valves and no inside containment isolation valves on the hydrogen recombiner discharge piping. The administrative controls applied, testing conducted and supporting piping analysis are all described in TSCR-130.

During the NRC review of TSCR-130, the ability to meet 10 CFR 50, Appendix A, GDC-56 was discussed (Primary Containment Isolation).

Since our valve configuration did not agree with any of the containment isolation valve configurations described in GDC-56, the NRC requested more information demonstrating the acceptability of our design. Their primary concern centered on our ability to reclose these containment isolation valves following a DBA when the hydrogen recombiner was in service and a leak is discovered in the system.

A leak in the system could make this area inaccessible due to  ;

radiological conditions. This has formed the basis for NRC acceptance of remote / manual valves with control room indication as a  :

suitable containment isolation valve. l kk h R p

P 0

'\)

B3nv3r Vclley Pow 3r Station, Unit No. 1 Dock 3t No. 50-334, Licensa No. DPR-66 Additional Information Supporting TSCR-130 Page 2 Within GDC-56, configurations other than those defined may be found acceptable if it is demonstrated that containment isolation provisions for a specific class of lines are acceptable on some other defined basis. We propose that the recombiner piping is a specific class of lines and our configuration will be demonstrated acceptable on the following basis:

1. The Beaver Valley design utilizes two 100%

redundant hydrogen recombiners installed and ready to be placed in service. There are no piping or electrical connections which need to be made prior to placing either unit in service. Each unit and its' associated piping is considered an extension of the containment pressure boundary when in service.

2. Beaver Valley utilizes a subatmospheric containment which is designed to be returned to a subatmospheric condition within 60 minutes following a DBA and maintained subatmospheric for an extended period of time. Current testing as required by technical specifications assures that containment leakage is maintained less than 0.1 percent of the containment volume per day.

Additionally, there are four narrow range and two wide range containment pressure instruments continually in service which are used to detect leakage into containment. All six instruments are qualified and powered from lE power sources.

Recorders also exist for trending purposes, one narrow range and one for wide range.

3. Based on our accident analysis, the hydrogen recombiners do not have to be placed in service until 2 days following a DBA. As a result, the containment is at a subatmospheric pressure and radiation levels have dropped significantly.

4. The hydrogen recombiners and control panels are located in the safeguards area which is serviced by the supplemental leak collection and release system which maintains all serviced areas at a pressure less than atmospheric and collects and filters all leakage from ESF components. This area is accessible following a DBA for both starting and stopping the recombiners.

Benvar Vnlley Powsr Station, Unit No. 1 Dockst No. 50-334, Licnnra No. DPR-66 Additional Information Supporting TSCR-130 Page 3

5. Since the containment is maintained subatmospheric

(-3.3 psig at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after a DBA, UFSAR figure 14.3-57), when the recombiners are placed in service the suction piping will also be at a subatmospheric condition.

Tests conducted during startup from our last refueling outage with the containment at 12.85 psia indicate one recombiner will be subatmospheric throughout its entire system, while the other may be at a pressure greater than atmospheric by 0.1 to 0.2 psi. Although we expect containment to be at a lower pressure following a DBA, this represented a potential for out-leakage, therefore, we analyzed all the recombiner discharge piping (both trains) from the skid connection through to the containment penetration. We have concluded this piping meets the break / crack exclusion criteria setforth in Branch Technical Position MEB 3-1, Postulated Rupture Locations in Fluid Piping Inside and Outside Containments. As a result, this piping is not expected to fail. This provides assurance that the recombiner discharge valves will be accessible for manual action during all periods following initial recombiner operation.

Additionally, the maximum working pressure of the recombiner system is less than 6 psig and the discharge piping is Class 151, schedule 80, 150 pound carbon steel. During operation, under accident conditions, the recombiner discharge piping would not exceed a working pressure of several inches of water at 150*F.

6. If instrumentation indicates an increase in containment pressure following the startup of the recombiners, this would lead operators to examine the recombiners as the source of containment in-leakage. If it was determined leakage existed in a component within the recombiner assembly, this leakage would be collected by the supplemental leak collection and release system as ESF leakage and the operators could shut down the affected recombiner. Since the containment is subatmospheric, the recombiner lines would be purged into containment and the operators could close the associated containment isolation valves as discussed above.

B cvsr Valley Powar Station, Unit No. 1 DockOt No. 50-334, Lic:nr3 No. DPR-66 Additional Information Supporting TSCR-130 Page 4

7. Dose rates at the hydrogen recombiner discharge containment isolation valves have been calculated to determine accessibility to these valves following a LOCA. The following potential sources were evaluated:

a. H2 recombiner discharge piping shine dose.

b. Main steam line penetration direct dose rate (containment isolation valves on the recombiner discharge are located in the Main Steam Valve Room)

c. Main steam line penetration scatter dose rate

d. Feedwater penetration direct and scatter dose rate.

e. Containment direct dose and skyshine dose rate.

f. Dose rate from 2-6 inch lines carrying containment sump water one floor below.

g. Dose rate due to main steam line shine.

h. Dose rate from airborne activity in main steam valve room (due to leak in recombiner piping)

1. Done rate from airborne activity in main steam valve room (due to 'eak in main steam piping)

j. Dose rate from airborne activity in main steam valve room (due to leakage in safety injection and recirc systems outside containment)

Based on a risk assessment of the above 10 items, only 5 (a, b, c, e, f) warranted evaluation as potential sources. The combined results from these five potential sources indicate that it would be feasible to have in individual enter the main steam valve room and operate the manual containment isolation valves for the hydrogen recombiner discharge piping and remain below the 10 CFR 50, Appendix A, GDC-19 limits.

Attached as Figure 1 is a station layout diagram which has been highlighted to indicate the location of the 2 hydrogen recombiners, the recombiner control panels and the location of the manual recombiner discharge / containment isolation valves. The system was designed to be locally operated. Based on the shielding study done at Beaver Valley following the TMI accident, access to the control <

l panel for system operation was confirmed. The control room is equipped with annunciations which indicate:

l Hydrogen Recombiner A Running Hydrogen Recombiner B Running 1 Recombiner Tripped

- Recombination Temperature Low l

B:cvsr Vclley Pow r Stction, Unit No. 1 Dock t No. 50-334, Licensa No. DPR-66 Additional Information Supporting TSCR-130 Page 5 Motor operated valves on the recombiner provide position indication at the local control panels. We have performed a preliminary estimate into the cost for modifying the recombiner system to provide remote / manual recombiner discharge / containment isolation valves with controls and position indication in the control room. The estimated cost to perform these upgrades is $1.1 million.

The design as it currently exists provides assurance that the recombiner controls and valves are accessible during periods when the recombiner would be required for service. There does not appear to be any significant increase in safety benefit that would warrant upgrading this system.

In order to provide further assurances of the acceptability of our recombiner design we will commit to do the following:

1. Test the Unit 1 piping between the containment isolation valves at 1.5 Pa during Appendix J testing to provide high assurance that the integrity of the piping is maintained.

2. Conduct leak testing of the recombiner units each refueling to provide high assurance that the integrity of the recombiner units is maintained.

3. Verify that the containment isolation valves on the recombiner systems are closed and locked shut once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> when Unit 1 is in Modes 1-4.

We belive our design meets the criteria of GDC-56 on the basis as defined above. If you have any questions on this submittal, please contact me or members of my staff.

Very trul yours,

1. L J. D.'Sieber Vice President, Nuclear Attachment

m . . . . . . _ _ _ _ _

Benvor Vollsy Pow 2r Station, Unit No. 1 Dockst No. 50-334, Licenca No. DPR-66 i Additional Information Supporting TSCR-130 j Page 6 t

i i

cc: Mr. W. M. Troskoski, Resident Inspector 4 U. S. Nuclear Regulatory Commission

- Beaver Valley Power Station 4 Shippingport, PA 15077 U. S. Nuclear Regulatory Commission i Regional Administrator i Region 1

! 631 Park Avenue i King of Prussia, PA 19406 i

Mr. Peter S. Tam l

U. S. Nuclear Regulatory Commission Project Directorate No. 2 Division of PWR Licensing - A Washington, DC 20555

- Mail Stop 316 Addressee only Director, Safety Evaluation & Control Virginia Electric & Power Company P.O. Box 26666 One James River Plaza i Richmond, VA 23261 1

1 l

l l

i

(

1 t

f l

1 i

i i i

'--~.

o. . - , j

[x ..

, ._n- ~-

( ..., , , e , .y tp

. ~. , . - . _ _ _ _

_;=q___ a.

N "" ./*""%4, r--h i 2 g._ "'O

~

J!! !'.: l :: ri,! ! .h -. -i'61 1@ ' p,

! = p" = =. l '

4' l Ll.) Lt LLJ_  !  %'?jiq ' '

a ,...

-p, o i , / 3.- =A -

le i , / m,. in s n'M 4-

.* 1 ,/ -

ut  ! *,.,mg =-,=* + .

s i,

~, f. m'. , ,-

-j ,

.a# ,s h y =. **'

o,DGTM, e6 ev 4 D.eum Pb&e6e t

/

V -.

hgg ' -

ID '

thom&e k - -.

N W ,. 's v f ,,

g I s

a y. .. . D- .!

af ; \ -*

ml '

lI i.M ~ '

~

.. .  ? s [* - . g n-e-.~~~

="" ********6**

l l ,

nu, .,n s g,J.' % d ,

cout .'es4.s.ornav evise e  ;; -

\" ,f- . g -

--A isses ran m er tow e U g N ~ ~ . f-

~ " ' " ~ ~

c::.& h]u..f $ ,. &

f .,A -

.:=., 7

' " _l ,..a,,-t . WN.g  ;

r- _o i i 4Ai*.

t ,, ,1 .

N if7

'N M

-...t-we?? eessatte.es pwene t

. ;j i

\

M,,

v7

', i,1.. -

1, Q~-

,

• Sg 4 Os.TCH p.m == d - p ence. geopa,h W teest.

.~ i, ,,

}g ,

e o ,-

, ,- .. p ,- -

V i g' 98 eguagg t *

.=

es.esE8 ses ,a ,s'

• • • ?

,f ' [' .

' pe,o6 , (gl;N's

%y ..

m

. \

,6*' s ')

• g l

,em- c' .

s' ' M . l Z' .4

-)( ixm oc k ^. % ' '

,' M

==-

Aeome Asey,w/

f,

,.._f \

y 7%aanga y r u. ~>

$$eLo4 7ic4 Vsf.L XS i'YA%" * ,

Pt Ai

(

l I I t

..m..~. . - . ~ .

!, l REV.2 (1-64_ -

$ l o'

2. -  ;

,.7 c .; f,. . i,. 7' k,, ..... . 2 ll .

t a a s s

[fI o n MF4'Or +i 'c.

moa ..~..s._  ;

.3 N '

g ,7 g ' . - - - - - - - - - - - - - - - -, , , .

g .

W d

( l! f@ 1 m i Q4 s

g , .cm

. 4. .g - . .r

= ,

a m c u wwiu 3:\ ---- }3,r {

' - a .

g

n. ..

% ,, 4,.

N---- ; ig /.,,,,_,,

g.g, ,

.% . .t ' i h, v " "*-o - ~ ou. .

1 f. .m m :::' y

.... ' '" a.u nu y-. 7

}

%gy n - > u. = ,r '

e a w . , c~ '

?~ q~. i.

l*

n.,. ,

(( , [ff '

I25 ;I

' k, )/ \ - -.--

=, s .

w~ J24m - . ~ . . .

A: mb

+ i .

.) (A'.'.', t 24.- .

N. ,,3 g - ' to a -- - #

47 r

":. .r'.',t .

7 mng  ; ,p

_ : .::::.p; V. ... ,' s

. .,+ /

'as. 3L / s 3 ,,3 , ~. c# , ,, ,,.

, gg -

'\.p ., y \g%)g_

g g h,,/ f^.

[v gr -\ "' [' -*

2 2, , , , ,

.,2.bf / , M d 2 2-.e

- _ k%

=

rr

,--- {

.4 , L.-.-

[ . .

[

=_*'ra w .- ,

,rh, .(tL \

.a g-

., m ...< , z.

n i ~ .3 9j >

W$, , .

a J mg ~.,'  ;*.ais _ .i_

e

_ _-, , a _.

oerucuso e t a ,4 c.

- J -

"wv p f, ' *"" b ,. . - 7.::. '-

5 ,4

"  ? =N= L':.1;,7 " '; . . .'." -

b;  : b}.*g, & y $$ # * *

'- s ' " " ' ' ' ,

m.. .

. ~.,

. - - , . . . . m<. . . -

s 4q es e,

) .

f r, i, j,/,

\  ! ...m......

's -; r s ,

M  :;r.'. . ,, s

. . . .u .. - ,u,u 2,md. A , .

. . ,,.o .... .

...,= _,us r

, abj ~ _ . . . i

,.4. . . ..

y j r-~ f Y.*o*.O[eI[a f

---o:xt.:;..L. , /

y 4

s

,; ,:,:;r,y,,,

, g @ .....-. -

==.----..e '

21 . .

1 > ..

1 o

- - -' n u. ,,, t.m,M.~.,1 . m,.

.t .. . ..

t. ',

i.

b.y _ g -* % '

y \"..g = 5 a ,TI

. '- m g- ,

e APERTURE m w .f s

, CAltD O

N'

/, Y ..

C'.ll.

. l RGUPE 5.1-1 5 P Avaltalite Ost

- ca.te.,.<, o, 4.t.m.,. One-1 A. REV. 8) y fEACTOR COPfT EL 767* - 10" BEAVER VALLEY POWER STATION UPET NO.1 LFDATED FNAL SAFETY ANALYSIG TEPORT l l s'%)W2Bb370- O/ - . -.. .

.-.