ML20049A465

Forwards Comments & marked-up Draft IE Bulletin on Flow Blockage of Cooling Water Sys by Clams & Silt.Draft Document Is More Appropriate for Issuance as IE Info Notice

ML20049A465
Person / Time
Site:	Arkansas Nuclear
Issue date:	03/10/1981
From:	Novak T Office of Nuclear Reactor Regulation
To:	Jordan E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
References
NUDOCS 8103240644
Download: ML20049A465 (6)

Text

-

TE'RA W

h t'

tiAR.10 L981 4

M

/f NAAfb1 MEMORANGUfl FOR:

E. L. Jordan, Deputy Director

.l3

% @gI A ;(2, Division of Resident and Regional 3q %

s

%Id a% h Reactor Inspection, IE

~~AW 4

FRON:

T. M. Novak, Assistant Director

/

s

\\"

for Operating Reactors, DL

• ' / l@

SUBJECT:

IE DRAFT BULLENTIN ON FLOW BLOCKAGE OF COOLING WATER SYSTEMS BY CLAMS AND SILT In response to your memorandum dated February 23, 1981 we have invited the principal NRR staff members involved with this matter as it arose on ANO-2 to corrent on the proposed bulletin. Their comments are attached.

In sumary, while we believe that collection of the large quantities of information required by the currently proposed ACTION STATEMENT would provide more comprehensive knowledge of where the clams and mussels reside we. feel that a balancing of the valve of this information against the licensee resource requirements to provide it does not. justify issuance of the raft document as a Bulletin. This conclusion takes into account that the most significant safety related aspects' of cooling water system performar.ce degradation are addressed by Technical Specification Surveillance Requirements on safety related cooling water systems, We suggest that the draft document is more appropriate for issuance as an IE Information Notice.

Original signed by l

Thc=as M. Novak T. M. Novak, Assistant Director for Operating Reactors, DL l

l Attacnment: As stated DISTR IWIT Wl-d % Fm1 Fii D NRC PDR L PDR ORB #3 Rdg TNovak DEisenhut i

RPurple

, g,

.JRoe

,)*,,~

.s JHeltemes

/

.4?'

' A[ '.". ' ',.., $ **,.,' J RMartin RClark PKreutzer (3) y. '],

g g _f//

l'

-" N.0R4y.3:D.L.

,;0RB=3.:

L,.

,,. g Sy3gDL Q )j.AD:CR:

QL.

& ave PKreutzer ar!tnfin.

'RAClark..

MNcvak.

3/ /31 3/ff/81 3/-/ /31 J/. /81.

1 d 0 324 0 hl.

':#!Ci " L F i C C A J -~~'

^

~

CCMMENTS OF:

R. Martin, PM for ANO-2 Operating Reactors Branch 53 It is recommended that this information be issued to licensees as an Information Notice since the chief safety concern is already believed to be adcressea by the Technical Specification Surveillance Requirements.

If, on the other hand, the existing TS's are considered inadequate to address this problem, then it would appear that if 1ssued as a Sulletin, it snould concentrate on remedying the TS inadequacies.

I am concerned atout the incremental effect that issuance of this draft as a Bulletin, with its presently stated ACTICN requirements, will have on,

the licensees' capability to devote attention to safety issues that may be more significant. When such requirements are imposed by decree on the licensees it reduces both the resources and the flexibility they nave available to respond to other issues that, frcm a technical viewpoint, may be more significant to the safe cperat'.cn of the plant. A considerati0n of the costs versus the benefits of sending the draf t cut as a Bulletin versus sending it as an Information Notice needs to be made.

The sixty day licensee response period is arbitrary. Considering the relative severity of this matter as a safety issue and the TS Surveillance Requirements in effect, 120 days is a =cre appropriate respcnse time if it is to be sent as a tulletin.

COMMENTS OF:

D. Pickett Operating Reacters Assessment Branch Doug provided the verbal ccmment that he had no comments on the detailed format and centent of the preposed Bulletin. Ocug also commented that he felt that this matter would more appropriately be addressed by 1ssuance of an Information Notice.

CCMMENTS OF:

M. Masnik Environmental Engineering Branch Mikes cccments are penciled onto the attachea copy of the proposed Oulletin.

~.

k 5 5 I';5.';:. : :i:.

b)6

/

Accessic.- r.:

Nj r C.G',s(pY pd. 6

(

~

gl,, s,.

y.a :

i -..

v.,.. Wy

%w....,

p t

tp

[J p

l ld

/ /*'

Ut;* 8 :n.(TAT. :..:

g' #f',/*

1

\\

[lU P. t.O.f F.

C. r.':' ' r.r'.T.. R y - *. t".'. * :.. Ci..'.'

(,j),/ /

w,,,,'

0T' TIC: "- :

f s.

• * 'b ;. ;.: r.1 ' n..i e' *i.l

'e ; e. :..:.' *..: d l

'i. A V.

Lis-6

&-L yc..c u...r.s r n,.gi, O. c. n-n:::

.e.

... J,,

s February 23, 1931 Oraft IE Bulletin 81- :

FLCW ELOCKAGE OF CCOLIf;3 'r!ATER TO SAFETY SYSTEM (n' a.7 " i.t e. C t n' et '.)

n'.'..;

-~

Y C u ~n - r.L.n*

ar.

C0P"e.'sF,'s.c :

n n

t.

MYTILUS SP. (f.USSic) v' l'1 Cesc-intion of Circumstances:

Cn Sep. ember 3,1950, Arkansas tieclear Cne (ANO), Unit 2, was shut c en af ter the.';RC Resident Inspector discovered that Unit 2 had failed to meet the technical specification requirements for mirica: service water flow rate tnrcugh the containment cooling units (CCUs). > Arkansas Power and Lign C :;a,y, v

ne 'icensee, ceter:ined that the inace:;ua-ficw was due te extensive piu::in:

Of tne CCUs by Asiatic cla s (Cerbicula p e:isa, a non-native fresh water "

~

j ed the service Oivalve : llusk).

fter cian sn = 5j r.ne licensee disassicbj$.Eter su;;1

.. iter?ipinoatthe(cc:ers.

Cl a:s aere f:en;' i. tr.e M-- 4i 3

i

'i.; at the inis. to the CCUs and in the :: 'er i-let water boxes.

5 e c'

e : lams f und were alive, but ::st cf tre. e-is wi e shells.

The si:s cf

/

c,,y., X. : _. e ) y.e e

_ _. tv '!.g% '.P V.,. a.

2. 2.,.h is

...oc<..... _

5 r..,

v..,e.

i. 2 2

..c.

r

e Carcanella Reservcir, is filtered before it is pu

ped through the syste.

Ine 5.rainers en the service water pump disenarces were examined and found te

.v.. -<..

m n.. n' L.e..u..%..e:..,.. c _, ) n..

f i....

c:inc,...e.....

e.

.:n, e.

.c m...

2

.c.

an sc e cf the shells found, i. appears tna cla s had bean gr

wing in.r.e system.

F:ll: wing the discovery of Asiatic cla s in ne containment c:clers of Unit 2,

ne licer.see examined cther equip:snt cooled ::y service water in bcth Units 1 an: 2.

Ins;wction of other hea. excnangers in tne Unit 2 service wa er syste: revealed some fouling or plugging of additi:nal coolers (seal water c:clers for both redundant containment spray pu :s and one icw pressure safety injection pump) due to a buildup of silt, corrosien products, and decris

(.ostly clam shell pieces).

The high pressure safety infection (HFSI) pump sarinc and seal c clers were found to have subs antial plugging in the 1 ka @f"p' '

i"-Jpipe service water supply lines.

Tne plugging resulted fr: 2 silt and

/'

.,. t 4

..-... s '~- 1. ro A.~c *.s.

qn sc u,,,gi.a,e,)

Cla shells were found in sc:e auxiliary building r::: coolers and in the auxiliary cooling water system which serves n:n-safe y-related equipment.

Flc rates ceasured during surveillance testing thrcugh the CCOs at ANO-21 ac caterierated over a number of =cnths with the most sicnificant re. duction cc:in 0 1I % E" f rc;. a cc:bined flow rate through the "C" and "0" CCUs of ',540-fi-c#ili'f f

yl..i ['"W;ee. on August 20, 1930.

Flushing after plan shutdowngesulted in a furtner r= duction in ficw.

Pr per ficw rates ' ere res.ored only af er the clan c=:ris t

tid :sen ren:ved manually frc: the C Us.

\\ M. f.'di s/

e

\\.. e. s.)

• e es l...=a Ins extrinetien of tne Uni service water sys.e: revet ed a the "C" anc "0" con;ainment ceciers were clogged by ciars.

Cla:s ware 'cund in the

7. e c m '

( 3 in 2 '.:: inlet hea:ers and in the iniet water bcxes.

However, no cla s were found in the "A" and "E" coolers.

This fauling was not discovered during surveillance testing because there was no ficw instrumentatinn on these ccclers.

Further investigation revealed that the service water strainer serving the "A" and "'" ccolers was intact, whereas the one serving the "C" and "0" coolers was broken.

The licensee ccn:luded that the cla:s fcund in tne "C" and "0" cociers cid not grow in the syste: but were sweet in throu:n

ne broken strainer.

Tne servi:e water syste: in Unit I was not f:uled other than stated above, and tne licenses attributed this to the fact that :ne service water pu:p scetiens are located behind the main condenser circulating pumps in the intake structure.

It was thought that silt and cla s entering the intake ba.vs would be sweet tnrough the condenser by the main circulating pumps and would not ac::: alate in tne ba:% of the intake bays.

In contrast, Unit 2 has no main circulating pu:;s in its intake stru::ure because condenser heat is ref s:ted through a ccoling v 'i l. a =. r

'e l o c..: '.s. e.

.a ' w.: '. =..

v.=..

v. c-a " l o c. =. ".. '. '...a e.".c.*.=.....

na..=:..'.'.

i

• - 2 i

." a " = c

.=o"=....)>..-

...,....... a.

g n j. 2 i. n. = k =. s *.. u - *w" r =., s i 'i

.=... w 'a =...=r. a ul. d.

.......:... ~. g.c.

ty]y 4.

g n j. g.. 2.,.

J g. 4. *. 1 r... j p....A. c_

.c

...=.. w...=.=.,

an.

2....

yi.

,e..... a

. ii

=

.y..

u. = v a.c..-...=..=..

. n.

.a = p. u.. o <..t 'c la m L * **

.- ~_......

a

..s

a...,. 3 3 s w a..,

.n

..,...e.

....u

.s i...-=.~.='....=.=.c-o '.. n' =. '. n '..= s' a..a3 s.

Tne Asiatic clam was first fcund in the United States in 1935 in the Columbia

-:..=.. c. =..=.

v... a - - *. r.. '.'..e ". i.. :. o r..

.ci.. e *.'a...,

c. a r.' i.. ". '. :. e n.

.= s : r. =..= d.

a -..- c e.

.r y.

7 ' e '. '. m-. =.e c =. =. V: l l e,"

. n c '. l =..= c...'.'

.c..=. c.c.

..a 4

i~.

.c...s.

....... co.

4 in A.trori y (TVA) power plants also have experienced fouling caused by these

.er.ev were first icund in the condensers an, service water systers at u

c. a..s.

ns12 1c c t--e w...

j... <eu o-s : n. a.e

.., c.... c.,_. Pl.. In,_c..-i.

. i

....:......n Ercwns erry Nuclear Plant.in October 1c74 caly a few mcnths after it wen:

.his initial c,as infestation at c,rowns rerry was enhanced :y t.

into cperatien.

tne f act that, during the final stages of c nstructi:n, the coolin, water systems were allowed to remain filled with water for long pericds of time while ine systems were not in use. -This conditica was conducive to the growth and accumulation of claas.

Since that tice, the Asiatic clam has spread across ne Tennessee Valley recien and is found at virtually all the TVA stear-electric and h.ydrcelectric c.eneratinc stations.

Present c:ntrol procedures fer Asiatic clams vary from station to station anc in ineir decree of ef fectiveness.

The use of shock chlorination during v/

surveillance testing as the only agdfod of centrolling biofouling by this cr; anis: appears to be ineffective.

The level of fouling has been redu:ed to a::e:ta:ie levels at TVA staticns by using continuous chlorination during peak s;awnin; pericds, clar. traps, and.cechanical cleaning during station cutages.

Tre rescits c.f a series of tests en mollusks performed at the Savannah F.iver l

Fa:ility sh:ced that mature Corbicula sp.

had as much as a 10 percent survivai

.< :. s.,.. e. s :4 = n., ; c.u.;.:..

a

...,,., c....=.:-.e

.z.,.

u,:.n, A - - e.,.

.a...

3.lg.

...s.

.I....i...

V.

O.;

2...

.....y p.

-s a :.. e :

• 1..a-

.4

... 3.::.

.k... : =. 4 s.

L.. s.

..:. i..s -.

ac.

.-_\\

s. f I

t-'

n

.,l g f... )

.?

(.s

-C

.b.*.g~.~..=,.".I

... e. i -

e.

r o. #. =. * *

• =*=.0

,.=*a.

2

...... :.. h. a -

a*

.8

...y e

s.e..

.3

7:: :

(c.:<.)

February 23,ig51 Fage 3 cf 4 rx...=*.=.'."..'..-3..-....e.

i..n

.c i. c., T "..,'. e. y- +..

a. d.

3

e.... s e.. e.-.

e..s.,.1 ] c. s.

. : - v = c.,

.ry creiisir.ary results incicating tnat a total enicrine residual of 0.30 to 0.40 ;;r

. c a.

. ~.,.

v" O a e. a n *. c o n '.. - I c f

+w..=.

.. n.e...s..u1s s.

r qm.1

.s.

-,e s.

r

..... e Asiatic r?am larvae.

I Corbicula sa.

has also shcwn an ama:inc. abilit.y to survive e'ven when re=cved e

frc :ne water.

Average times to ceatn when l=ft in the air have been reported fer icw relative humidity as 5.7 days at 30*" (c5'F) anc 13.9 days at 20*C (55'F) an: fer high relative humidity as 2.3 cays at 30 C and 25.5 days at 2 v.- o r..

r..-. ' i - ". l = c o.

o r. '. '. e c... =-, t..=...d, P..:.e

<..,..=.. 5 e. =..=. a. r.

s c.n s '. '. #. v. '4 '.o

.'.e.=..

4 its:s perf:rmed by pf,A resul ed in 100 percent. :r ality of cla: larvae, very clans, and 22: ci'ab.svnentheywere Mature cia s, up to 14 :f >CaYi'ex; sed to 47*C (117*F) water fo vcun:

ais: :ested and all died at 47

• u-2 cine as.

fellcwing a 2-minute expcsure.

A statistical analysis of the -minute

- *:..,=..='.'. *. c. '. 4.0*C (1.2^ F) w.=s..e.ac>ary

e. x -..e......

e* d.:.=. a. v c..= i. =. d.

.... = *. e

reach the 55 percen confidence level of c-tality for clams of tne size

. :..: +.. s..

c. e. a,. :,g 16.0 e

'. g e.

k, a. q.

c..'. 3w n..

k. s...... c.. s.ee

...~.m.

s. y.s o.

-o.d:*a.,

'..=..s'.

.o v.

ercent rtali:y for the Asiatic clar.

-At 1.N, tre service water system was susr.e:.;;n ei w (,./Cc

,r water cbtainec tr:: re auxis.ary bciser for r

I;;r:xicately one half neur; 100 percent scr:a:i y was expected.

c. i. i. c...,..,1,..

b.. a c. c.. "... c. d.

. i '. b.. ". e. e. =. ': s ' ". " ' '. ". e.

c a.. ',.

..'. := e='...ns c'.

assels na.e caused fica clocka;e of ccoling wa ir :: safety-related equi; ent it acclear pla. s such as Pilgri and Mills :nt.

Unlike the Asiatic clam,

. ;ssels cause bicfculing in salt water cocii. ; systems.

i

- i.m c i. :..:

- e.: p. c.y i:- ic:.S

.. n ir.

-:iders cf 0;erating Licenses or Ccnstructi:n Fermits:

i AW w cmfm.d 6eid Determine, based en the results of rs_:r':

......cedi;i.;;;al tenitoring

.u.

,.ogrc..s n.>...

..,2

.. a.... :-en--p.. z..pp22.,.a,. ion as r.

.....,,:.,,;..,a

.., a.. ;,..,,

r.......

_.w.. :..

e,. : s t... ;M wh =..~u.e r o r n u..

<~w,

._....c....

..a.

._2.-

.c -....,

Cerbicula sp.

(Asia-ic cla-) or Mvtilus sp.

( Ussel) is present in the vicinity of the station in either tne s:u te er receiving water body.

A re;crt shall be su::itted indicating tr.e ;resence or absence of th+ss owe. cr.

he scur':e of this infer:ationI ser, indicate thdA ho 'S cf the. static.; if p-e M idi.'.::*.': ',"$ vicinity creanisms in the w.

inflatest sa pie date of W

of the ::nitorine. Precra that -as used tc nahe tne determination of presence or absence, and a brief descri:ti:n of the acaitoring program.

have bean cor ductsd in the vicinit" of the If no monitorinc. m ;..

.a s

r statica that c:ule reascnably be expected t: cetect these organists, this shculd be so stated.

7.. :... ( u.rw. e. s i.,

-T :. i...... C:, j :-l a

Fac,e ' cf 4 C.

..... - ""'"*** C

• * * * '.*. " " ~.#. ^. 7. * * * ~.. i '. C

1. ^*

"":1..... ". S * #... 3. y '. c' r.. e

~*

,=..t:

. i.

.L a. c... e..... g 4. 3.gg

.ci..a c. 9,.: j e.. s..e,, e p

.2 -.. j.e.,...e

p.... ], 2

=....

i r a c.

r source er re:eiving water:::y snali in:lede in the aforerentioned reper-the following information regarding the cocling wa er systems that maisJ b= su :e-tible to the intrusien of such crganisms:

e a.

A list of any fire ;;rstection system er safety-related systers that directly circulate wa:er cbtained frc: the source waterbody tr.at are currently being kept full cf v.a.er and the interfa:ing sys.e:s and equipment c cled by tnese same water systems; b.

A statement as to whether tnese ciganisms have ever been foun: in M.

-g e c.bc. e.

5,y s u.n s. +

c.

A cescriptio.n of anv surveillance crocra in effect or planne: that assures t +Wi *W=" s.vstems 'are nct being fouled bv thess

~

cr;snisms and the fra:;en:.v c:. sur elliance. and n.:n.,.s.

c,...

. ew.....:...

......, C.

D :... l., w e

t.a, Q,J 1,... :.. c:

C.e...; y s.6.:....:..

d.

p

- e... :..a.,

a. e

s..u

.u..s y a.. :., e r y. : ] ]

..!.:n

w. y.cy.u. en.

s

r..

a r.......

. '. s. '. ] -. a y i d. s.

t... s.

r e.. ". e.. *w..s e,.. *

1. . # :.. 's *i. i a. c g j +..g e r.=. r.: t.. a.a

• . e. - : c. e.

m e.

..y 3

e..:11+w:ees ith e

..:e.

..J. c..:.

a., : c a C.

a

.......'Cs..:

04.. :.

we.=

i=wa

i.. e.

a. r 120 d=ssi s.

• '.'.#.a

.....-+jw.3

-:...j.e

c. h.a. *1 ] -.3 y :. C a.

• "t e. 6. y',^ * *.

p.

wi r.

.. c.. e :....:. 1.,

3...6..:..

c. i - - =. -. ~ 23..

c-. h.

n.....o

...,.e.

se..-...

s.

.e.

~.

o

.3..

..r.

.c.,. 1 -. 1.:.e.

e.

s.

.....,. C

..3_,..,,.. c S.c..:. a e

... e.

.e.

C

.t,i.e:

e...,.,e.

h e-c.,... e e..

.. - c 5 nww

... = i l.

.., a.

e i w.... m. a.....

• be. r. r o.,.. r. c.

~..w.a c-.3.

. 3. 3 R2ric...=] C ee.j C*.

• .*.d c-e

...i 2..

a i

e s

.V.-",

., e.

n.1. e.. m., C,se..

e. C-

• E :. ~ u. e. :..

e i 1nn..en c r e.a....e n s,

c.-. :. e :. a

.s

.n st i

r.

w.

. : :....., r.

t..

2 c,.: :. o.

r s

e:uest f:r infer:a.ica was appr ved b;. G.0 u car. a blanket clearance

2. :e uv/2

n.. h expires Neve ber.0,19::.

t.:m. ants en burden an:. duplication ic 2

c.:'d be directed te U.S. General Acccunting Office, Regulatory Repcrts Review, F.::: 5'.05, 4:1 'ignth Street, N.W., k'ashington, D.C.

20548

+- MA %

b.

ca keo ve. *.

T4' S c, sde.

'?lc. CC'^f'C-S id' e ' CY *, CI d t ' Ud-h

~,p h m c:r r-u,w+ c f +Le b% he w mJ & 1 4g [-cdg wuS c t St u' d+ 't,I M cow 1

j c, c, ecj,,.e ac6 s ce f h f o.t,

t.cb2k 4.'dM Cub h-/d'-

m:e u,t,,e Yn ks O.

.