ML20141B488

Forwards Addl Info Completing Response to Confirmatory Item C-21, Routing of Offsite Power Circuits, Per Discussions W/Nrc Re Adequacy of Guardrails Provided on Bridges Crossing 345 Kv SF6 Bus Work

ML20141B488
Person / Time
Site:	Seabrook
Issue date:	04/03/1986
From:	Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	Noonan V Office of Nuclear Reactor Regulation
References
SBN-991, NUDOCS 8604070046
Download: ML20141B488 (12)

Text

. .

O <

M SEABROOK STATION Engineering Office Pub 8C Service of New Mcumpshte Now Hampshire Yonkee Division April 3, 1986 SBN-991 T.F. 7.1.99 United States Nuclear Regulatory Commission Washington, DC 20555 Attention: Mr. Vincent S. Noonan, Project Director PWR Project Directorate No. 5

References:

(a) Construction Permits CPPR-135 and CPPR-136, Docket Nos. 50-443 and 50-444 (b) PSNH Letter (SBN-903), dated November 27, 1985,

" Resolution of Power System Branch Confirmatory Items,"

J. DeVincentis to G. W. Knighton

Subject:

Confirmatory Item C-21, " Routing of Off-Site Power Circuits,"

Additional Information on Guardrails

Dear Sir:

The information in the attached enclosure is being furnished as a result or our discussions with the Staff regarding the adequacy of the guardrails provided on the bridges crossing the 345 kV SF6 bus work. This information augments that which was provided in Reference (b) in response to Confirmatory Item C-21, " Routing of Off-Site Power Circuits."

Since this completes our riesponse to the above-referenced confirmatory item, we request its resolution be reflected in the next supplement to Seabrook Station's SER.

Very truly yours, John DeVincentis, Director Engineering and Licensing Enclosures cc: Atomic Safety and Licensing Board Service List 8604070046 PDR ADOCK %h43PDR E

ht P.O Box 300 Seobrook.NH03874 Tetophone(603)474-9521 \

J

i Dicn3 Curern Patcr J. Mathswa, M2yce j Harmon & Weiss City Hall  ;

20001 S. Street, N.W. Newburyport, MA 01950 l l

Suite 430 Washington, D.C. 20009 Calvin A. Canney City Manager Sherwin E. Turk, Esq. City Hall Office of the Executive Legal Director 126 Daniel Street U.S. Nuclear Regulatory Commission Portsmouth, NH 03501 Washington, DC 20555 Stephen E. Merrill Robert A. Backus, Esquire Attorney General 116 Lowell Street Dana Bisbee, Esquire P.O. Box 516 Assistant Attorney General Manchester, NH 03105 Office of the Attorney General 25 Capitol Street Philip Ahrens, Esquire Concord, NH 03301-6397 Assistant Attorney General Department of The Attorney General Mr. J. P. Nadeau Statehouse Station #6 Selectmen's Office Augusta. ME 04333 10 Central Road Rye, NH 03870 Mrs. Sandra Cavutis Designated Representative of Mr. Angie Machiros the Town of Kensington Chairman of the Board of Selectmen RFD 1 Town of Newbury East Kingston, NH 03827 Newbury, MA 01950 Jo Ann Shotwell, Esquire Mr. William S. Lord Assistant Attorney General Board of Selectmen Environmental Protection Bureau Town Hall - Friend Street Department of the Attorney General Amesbury, MA 01913 One Ashburton Place,19th Floor Boston, MA 02108 Senator Cordon J. Humphrey 1 Pillsbury Street Senator Gordon J. Humphrey Concord, NH 03301 U.S. Senate (ATTN: Herb Boynton)

Washington, DC 20510 l (ATTN: Tom Burack) H. Joseph Flynn office of General Counsel Diana P. Randall Federal Emergency Management Agency 70 Collins Street 500 C Street, SW Seabrook, NH 03874 Washington, DC 20472 Richard A. Hampe, Esq. Matthew T. Brock, Esq.

l Hampe and McNicholas Shaines, Madrigan & McEachern 35 Pleasant Street 25 Maplewood Avenue Concord, NH 03301 P.O. Box 360 Portsmouth, NH 03801 Donald E. Chick Town Manager Cary W. Holmes, Esq.

Town of Exeter Holmes & Ells 10 Front Street 4 7 Winnacunnet Road Exeter, NH 03833 Hampton, NH 03841 Brentwood Board of Selectmen Ed Thomas RFD Dalton Road FEMA Region I Brentwood, NH 03833 John W. McCormack PO & Courthouse Boston, MA 02109

SBN 991 ENCLOSURE Additional Information on Cuardrails (Confirmatory Item C-21) i

~-

ENCLOSURE Additional Information ReKardinz Protection of SF5_ Bus Work from Vehicular Traffic General Design Celterion 17 requires that the two circuits providing electric power from the transmission network to the on-site electric distribution system be designed and located so as to minimize to the extent practical the likelihood of their simultaneous failure under operating and postulated accidents.

For the Seabrook design, the connection of these circuits from the transmission line terminating structures to the switchyard is done utilizing gas insulated (SF6 ) metallic bus work; refer to FSAR Figures 8.2-7 and 0.2-8 (attached). As shown on these figures, the SF6 bus ~ work runs under two access bridges (Bridge A and Bridge B).

We believe that the following measures taken to protect the SF6 bus work from vehicular traffic on the access bridges satisfy the requirements of General Design Criteria 17 in that they minimize to the extent practical the likelihood of a vehicular accident causing the simultaneous failure of two off-site circuits.

(A) Vehicular traffic on these bridges is subject to strict plant-regulated speed limits: 15 miles per hour for Bridge A and five miles per hour for Bridge B. These speed limits will be posted and will be enforced by the plant's security forces located at the Gate House. Photograph A shows the proximity of the Gate House to the bridges. Because of this proximity, there is insufficient distance for a vehicle to accelerate to an unacceptable speed as it enters the site and proceeds towards Bridge A.

Vehicular access to Bridge B is controlled by the security forces in the Gate House. If there is a need for a vehicle to cross the bridge, a guard will have to walk out and remove the chain barrier which blocks access to Bridge B.

There will be no access on these bridges for Unit II construction traffic should Unit II construction resume. There is a fence line separating Unit I area from Unit II and other construction areas.

(B) Heavy guardrails are provided on the bridges. (Refer to Photographs B and C.) These guardrails are designed and constructed in accordance with AASHTO (American Association of State Highway and Transportation Officials) requirements. Guardrails designed per these requirements have been successfully tested by AASHTO to sustain a 250 impact from a 4,500-pound car traveling at 60 miles per hour. For details of the I design and material used for the guardrails, refer to UE&C i

calculation SS-15.

(C) Each SF6 bus work constituting a circuit (three tubular buses per circuit) which runs under the bridges is in its own concrete compartment and is separated by the adjacent one by a one-foot thick concrete wall.

Refer to Photographs D and E for details.

t ENCLOSURE (Continued)

Additional Information Regardina Protection l of SFA Bus Work from Vehicular Traffic r

4 (D) A galvanized steel protective grating is installed on top of the walls separating the SF6 bus work. Refer to photographs for views of the

- grating. (End pieces of grating adjacent to the bridges have not yet been installed.)

(E) Additional guardrails are provided as shown in Attachment A to guide access to the bridges. The design of this type of guardrail is as shown in Attachment B.

Keeping in mind the above-described protective measures, we can now evaluate the effect of a theoretical catastrophic event which would be a vehicle traveling at the posted speed limits and veering left or right while crossing the bridge to the point where it hits the guardrail.

We believe that the vehicle will be slowed down or stopped by the impact on the guardrail depending, of course, on the size of the vehicle. ,

The AASHTO standard specification which was utilized for the construction of the guardrails states that the primary purpose of traffic railing is to contain the average vehicle using the structure, while taking into consideration the protection to vehicles on roadways being overcrossed; in our case, this being the SF6 bus work.

It is recognized that the AASHTO standard refers to average vehicle; in our specific situation, the vehicle in question could range from regular passenger car to a delivery oil truck or other large cargo truck. We believe though that the difference in speed (highway speeds versus plant speeds of five to 15 riles per hour) provides adequate margin since the kinetic energy available

- for impact at the Seabrook speed limits is far less than that present in the test performed by AASHTO (Reference (B) above)..

If the vehicle is not totally stopped by the impact on the guardrail, then the grating and the concrete walls separating the SF6 bus work will further slow down the vehicle. As shown on Photographs D and E, the SF6 bus work is located at the bottom of the concrete compartments, and there is at least a two-foot distance between the top of the tubular bus to the top of the concrete wall where the metal grating rests so that the vehicle cannot impact two circuits simultaneously.

We would also like to point out that these bridges and SF6 bus work have been in existence for at least four years, and there have been no accidents involving this equipment even considering the heavy traffic during construction of Unit I.

In conclusion, we believe that the above demonstraten that it is not credible i to postulate that a vehicle could go through all these protective measures and still cause failure of two off-site circuits (i.e., damage the SF6 bus work in two adjacent concrete compartments).

L

F m

j Amendment 50 l August 1983

( __ _ ~ ~ - ,

I I_,n-;.=.=17d1 xe l- mn r - a ra _Q.  ; 1 w

,. 1 , , .  ;

re- ce1 m.Lx a . ..

NY.4.h/-'

. m ,_.

m . 4%

9 9

~

4k ~

E$Wirl Ik@

e*\

\x g+reeme= ij ,,m w . g b2 ,9i__vd L

m .

s' ss\ j,e . g

.t . . . . ,

\ -;

• x. s.u w.,m.ma u u:n

\ -@ kb j

i ' 'P 4 -f%, ~ ~ ~ , >

s- x c_ es_ -

- v,.. -_

.'s --__3

,_" __ m,,

'- x,c s~. sy . , , ,

fi j

. q .__ _ _ _ __ _ . , - - ~ ~~ ~ ~.  !

GRt 04 f., Ks N T' - ~

l

- 4

^_ ___ _ . q' .

5_

- ~._

'~

t m,. _

3 7 ==== = x ' * *

\ g j ._._'#

,', ,,[/ A$5h. . - y* h . s .f.- L.((

~

}i ,

n. \

I

,~

g q

.\/ W1=>

.s J ~ %B

" p' v

,4. + ,

f%.y 3

~

i

\ i ,,,. '36Tfn "***"'*'- I La ....

C '

j l i I ,..<j ' ' ' ~

7. - ' ..i'] ~

s ti ...

{1} { j;* t l .i ...j"

_!w w}L 1

l_ T

,y p.,y J- "

- tqs? :-

p

'tt^-

'.,--<====:==%-.ai c.,

a.

-._) E'

,7 gf ,- e,, - - -

=. em 3- ps I / g n.n . . , - - - n-k-.-. .

k ,,-.n-

p / mwa w n--- .~.,. s e , , r o e

) l J D l t.. . . - - -. ),... .-- >

PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE 345 KV SWITCHING STATION SEABROOK STATION - UNITS 1 & 2 ARRANGEMENT AND INTERCONNECTIONS FINAL SAFETY ANALYSIS REPOHi 9 763- F-309826 l FIGURE 8 2-7

i . . . .

Amendment 50 August 1983

>.e 'l ,w _--- ,,,,.

' p.=::p r ", ".1 kw di 1

mfr

(% 4 M

i NN y

0/

,/,- p.= / ?N ~ ~<.r.m

- 4, 9:s ea

.c . g '- . x. i  : i m.u

[/ . .MX  !

1

{ i._b -_. '

.A_

+1 -e  ! 4 -

i

1. .4. .

~ / .= -

- - +

i r , , NN s ,

I N. M./ QN..

1d % 'n~

Ngg l T e3 I

I

. x3 g

..p.,v- a  ! - z, v a.w m_;

. L.J. ra 6

c. . .

u t x we , ,

s.

g, . . 7-

\

i ,

_4_~_____,____..._gw.,

g w..

3 1

,.~,...,,,.,4.

--s ' ,g ll  ; .>---. E '-'r- g; hb.cg[* 4 i, -

- - ~ _ .g.

,, _p qa\, '\g:;(Y s

s f' cc.,Q- -

.u y.\ ,%/

"}% , ~** *~' .s m, N

U ' .R , e .- ~

~.'

k [\ sx;g,c 4 --

l ' \{N tF+ ;

=-

s.

4 .  :+x -

~

',m } ','

i

I, . b j ,. EId*76F

!. L_..

.I 345 KV BUS DUCT TO PUBLIC SERVICE COMPANY OF NEW HAMPSHIRE TERMINATING TOWERS ARRANGEMENT SEADAOOK STATION - UNITS 1 & 2 FINAL SAFETY ANA LYSIS REPOAT 9763-F-309827 l FIGURE 8 2 8

, NY bCON(@

g\

\ h \k -

s D WW * /. BRIDGE 8 S,64486 B

, , x Y conJC OE

1. g RATIN C.

k

• 7yp

• gg-n/ SQ '$-

[

~.. ' ,dE4 4

,/ 7p m.

.csoogo f x

%" C.MT%

.a,,

21 (4 g

~

cca.T (~ TCE ft wetos O to -

ss

( /'

'~

T A

1. DM v

A 0

Sts(vf (e GRAM ca4Y) s [ , L 'Y . 3 Te*,,- 9 Sit CET. 'S \ '

\e

~

• es4c - .k eso m S'A i, -J k ' .b_

+ i.q g gu.ep es sL- J 41 g

b #

~

Q t- -

.i\

d Gua=o a^8'

. s s* _ . . ... ,< w- e

. Em \

's,

'K f.,

m ott. IC5CT4 B C ST **-

\\ -

\

s o. ova n a m c u,t _. ' \% Sf4SEI ( (D

$ NF

- ce mm Tg -

y] g .

,.2 , r,e i

( xm as-t+ paw '

Qf y v. . ,

, ,, 5 gh Stt D81 eseo40 k

8 g k*/ '

16

' Jef.ek _'. \\tl*4h _l, ,g 3 ..

b 9 -8 SS 4 . o v._/ V,' 7'*4_ 'u, y

2 ROAD eso,595

~

40600464

\

NNy\

\

\ \',

= = = = = = r ^"e 3

%C(, A' ---- ~T, \\ == oe r '

y i r, , co

., a io s.~e s oo.

., . , e,.,s4s ,'e,s '.,m', , ,['o+=4 *e y .o. .

wi S** pipe BaeRIER see o.v.ei.iosc7G A ] ,,,

4 gM* .ssl ', ,J h ,, y

~ ~ ~

g'g[d

[~

4 ( ~ ). k 'niE N d 5 j

CvMb RML h ,

~

. . _ , . u. A a ,_.. <,s ,, __

w- cv nuo w-wsa i

(_., _ . _ ,_.j -d

. _ L_ + _ _. N /

'_.; *L wa4*,,p.- i .. ~

y r~r 1~ 7 i!_ .~ lll V m PO. !.

53.1 1

1 l

b. . m\ ,-._ .

{

=

ff h we a v.aa e ]

\

.W

,g mn mi B

siM us y r**L. *; AT. ,

F_tavarica s , Post . o Be a a G oa. o P a.s . ,

5. ** = . . , ,

V$ 1 )

met.: saa moey.g,nava.a m t.,,as: g , . , , , ,_, q

, d,,u. s~! ..  %.

E L.' 's.m.

y D r.C'1064 T he elv R a t s. E.L.anAEn.T POSTS { 62 Ant SHOwN ASOVt ARE COR PICTURE PURPOSE S Oh }.

FCt CSTAtLS. 32t 3*ANDARD SNttiS m G 40, CtP* CF PUBL C WCRAS R urGus sys "S*A's Qt Ntv HavoSMiRE STAACARD STRUC?ut&5*

~

GUA.73 RA'r 69-:11 IS UStD VrTH G d e.S~A *G *C5'$.

.<*s : e 8 o r 2 72 Sattf REPRODvGED Facu 5'S *J H DwG Nr. R -700- 3716 R E V. J DATE a*.,

A

_

en,.

/si w iiw.

w- u Civit NORT H ACCESS ROAD v e. DETAtts a PUGUS SENUICE CO. OF Maar MAtsPOMestE

-^

STAftops y

i OE o... mm a -, . .. ,

% = = . O. -w M4 Ji. mA .'z a dig - um

- - 4 ne.-... e. tAllTS I

• 2 9L3 F-t03214

-. . , - a s === _ _ _ _= ... .

n. - i . - . . .

WM t .2

~

& 4'8 RSET .- E e t- t M EGE e I m .NW la w 4

• .. * * * -e a 9.* -

e*s s,sy v , , m _ p p. . .y m _ pe, , , ,_

h-5 k O N O k b ' ] -

INF0 DEY

m - -u . _.m.4, .,a ., a-. _ . _ _ _ . 4 ..__w --- - - - - - - - - - - , _ _ _ _ _ _ _ . _ _ _ _ _

• • e

. , R* y l?,  : $

F *w scywa.yg Ouhl ' N;(($-

G AT.h. d 4 - 0.a it  !

I '

f .s V

J <

j _

,o A '

~

\

4

• m t

\ D

&N 99ato CA) l l _ a ~- ,

t , e u--

^';;,;,_q i- gg F l l Mf' (( I v-

~- .

t Lp

~a

.. s 5

. .~- .. 5 2 nak 9t4oTo @

-- _ - --- -- - - .,__.m a - e m - a ,_s._. - - - --

% O Y ,)

, , *1 ,. . .

h.g '

_;p

, .T- 1

4 N. r~

< 'Q -

- imana$r ]7

= ,. 6g i

g g g p aa m,. m.. n :._i c;u ,am ,=

b '

l egri e n. $=

6  % .

+ -

~;. -

,.[.,.,~.,,,.p

~ ' ~ '

l I '

ar* :s...h"~ y- - l , ..

, y  : . -

I 2..; v / a;. .

s.-  ; . , . .c i

. . e

/

Av.e 4

e e ,

?HoTo @

~

1. --i- o ---_-----2-_ - . e m e - - ,_e _a,__ 4 , ---_ - - - ,

O g

I ,

i r

l l

g' l

- =

l 9 . .

/

i PWD h

.