ML19305D062

Response to Ucs Second Set of Interrogatories Re Restart Proceeding.Includes Info Re Prevention of Void Formation & Reduction of Natural Circulation Loss.Gf Trowbridge 800331 Forwarding Ltr to Er Weiss Encl

ML19305D062
Person / Time
Site:	Three Mile Island
Issue date:	03/31/1980
From:	Trowbridge G METROPOLITAN EDISON CO., SHAW, PITTMAN, POTTS & TROWBRIDGE
To:	UNION OF CONCERNED SCIENTISTS
Shared Package
ML19305D049	List: ML19305D048 ML19305D051 ML19305D058 ML19305D060 ML19305D062 ML19305D065 ML19305D070 ML19305D073 ML19305D077 ML19305D082 ML19305D089 ML19305D096 ML19305D102 ML19305D108
References
NUDOCS 8004140019
Download: ML19305D062 (8)

Text

-

Lic 3/31/80 0m * .

UNITED STATES OF AMERICA NUCLEAR REGULATORY Cole 1ISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of ')

)

METROPOLITAN EDISON COMPANY ) Docket No. 50-289

) (Restart)

(Three Mile Island Nuclear )

O ma y nv ,

Station, Unit 1) )

gg 6 a' , - 1 km 9

LICENSEE'S RESPONSES TO UCS SECOND SET OF INTERROGATORIES

• ~

errc-h ' ~ '::. 1C?

With reference to your answer to UCS Interrogatory #7, which of the short or long term measures recommended by the staff and to be implemented by licensee "will reduce the likelihood of void formation?" Explain the basis of your response.

Response

'~

(O The sbert and ktg ter- - Easures rect- ended bv the staff and to be implementeo by the iicer.see unicn are consicared to reduce :ns lheli-hood of void formation are discussed below':

1. EFW Timeliness and Reliability Improvements in the timeliness and reliability of the emergency feedwater system (EFh') provide additional assurance that the syste i will be available upon demand to remove reactor decay heat and reduce the likelihood of void formation.

2. Independence of ER.' from ICS Capability to operate the EFW independent of the integrated control system (ICS) serves to assure that a malfunction in the normal feedwater control system does not impair the ability to deliver emergency feedwater. This -provides additional assurance that the EFW will be available upon demand to remove. reactor decay heat and reduce the likelihood of void formation.

~

3. Reactor Trip on loss of Main Feedwater Direct reactor trip on loss of' main feedwater results in a Lprompt :

decrease in core heat.ceneration. This.provides-an acditional margin for avoiding a reactor coolant pressure increase which' might challence the pressurizer' relief cr. safety valves. This

reduces. the. probability of. a valve sticking open, causing a loss

. of' coolant accident (LOCA) and potential-void formation.

8004140013-

. .

4

~ ~

Il :O

4. Analysis of Small Breaks Additional analyses of small "reak LOCA's, and development and implementation of the related coerating guidelines will serve ~

to assure that procedures are available for small breaks whicn will reduce the likelihood of void fomation.

5. Retraining of Operators Retraining provides additional assurance that ooerators will re-spond in a proper and timely manner to piant conditions which could lead to void format;on in order to reduce the likelihood of such an occurence.

, 6. IE Bulletins79-05A and 79-05B The actions identified by IE Bulletins79-05A and 79-053 are directed at preventing a recurrence of events similar to those which led to the Tl'I-2 accident. Imolementation will therefore serve to reduce the likei.ihood of vo'id formation.

7. Trainino of Operations Staff See Item 5 above.

8. Facility Procedures Upgrading of facility procedures will crovide further assuran:e that effective instructions are available to operating personnel

. to reduce the likelihood of void formation.

9. Plant Maintenance See item 5 above.

10. Lessons Learned Category A Items Implementation of LL Item 2.1.1 will provide additional assurance that pressurizer heaters c.an be operated, that the pressurizer relief valve' can be closed and/or isolated, and that pressurizer level indication is available. Each of these serves.to assure that primary system conditions can be controlled to reduce the likelihood of void formation. Imolementation of LL Item 2.1.2 will provide additional assurance that a pressurizer relief or safety valve will not stick open and potentially result in void formation. Impl e-mentation of LL Item 2.1.3.a will provide additional assurance that

, in the event of a pressurizer relief or safety valve sticking open this condition can be recoonized and action taken to reduce the likelihood of void formatio'n. Implementation of LL Item 2.1.3.b will provide additional assurance that operating personnel can recognize 4

-%m -m e <e -,e. -.-e, - -. ..% .

3-D

~D)

_aoM e j\\

]O TYS 2, $lfd =>

~

a condition of imminent inadequate core cooling and take timely and appropriate action to reduce .the likelinced of void formation. ~

With regard to LL Items 2.1.7.a and 2.1.7.b, see Item 1 above.

Implementation of LL Item 2.1.9 will provide additional assurance that operating personnel can properly diagnose and correctly re- .

spond to unanticipated-situations which could result in void formation to reduce the likelihood of such an occurence.

11. Srall Break Analysis and Procedures See Item 4 above.

(B) " Status Report on the Evaluation of Licensee's Compliance with the NRC Order dated August 9,1979 Metropolitan Edison Company, et al Three Mile Island Nuclear Station Unit- 1 Docket No. 50-289", January 11, 1980.

(C) None. -

(D) 'See introductory comments.

(E) See introductory comm.ents. '

Interrogatory No.181 L' sin; ycyr definitior Of "na ural circulasion" as given in res7cnse to UCS Interrogatory e6, identify whicn of the short or long term measures -

recommended by the staff and to be implemented by licensee will' prevent or reduce t".e likelihood of loss of natural circulation. Exolain the basis for ycur response.

Resconse

.(A) The short and long term measures recommended by the staff and to be imolemented by the licensee which are considered to prevent or reduce the likelihood of loss of natural circulation are discussed below:

1. EFW Timeliness and Reliability Improvements in the timeliness and reliability of the emergency feedwater sys em (EFW) provide additional assurance that the system will be available upon demand to remove reactor decay heac .

and reduce the likelihood of the loss of natural circulation.

P

2. Indeoendence of EFW from ICS Capability to operate the EFW independent of the integrated' control system (ICS) serves to assure that a malfunction in the normal feedwater. control system does not impair the ability to deliver emergency feedwater. .This provides additional assurance that the EFW will be available upon demand to remove reactor decay heat and reduce the likelihood of the loss of natural circulation.

3wa..,e-e-r%w ,,- m--%_ .,#.ee a e - - , = , .

~

.D U D r

0 "@W C R ID & 1

3. Reactor Trip on Loss of Main Feedwater Direct reactor trip on loss of main feedwater results in a prompt decrease in core heat generation. This provides an additional .

margin for avoiding a reactor coolant pressure increase which might challenge the pressurizer relief or safety valves. This reduces-the i

probability of a valve sticking open, causing a loss of coolant accident (LOCA) which in turn could result in the loss of natural circulation.

4. Analysis of Small Breaks

' Additional analysis of small break LOCA's,. and development and imple-mentation of the related operating guidelines, will serve to assure that procedures are available for small breaks which will reduce the likelihood of the loss of natural circulation.

5. Retrainino of Ooerators

- Retraining provides additional assurance that operators will respond 1

in a proper and timely manner to reduce the likelihood that a loss of natural circulation does not occur.

4

6. IE Bulletins79-05A and 79-053 The actions identified by IE Bulletins79-05A and 79-058 are directed at preventing a recurrence of events similar to those wnich led to the TMI-2 accident. Implementation will therefore serve to reduce the likelihood of a loss of natural circulation.

. 7. Traininc of Ocerations Staff See Item 5 above.

8. Facility Procedures -

Upgrading of facility procedures will provide further assurance that effective instructions are available to operating personnel to reduce the likelihood of a loss of natural circulation.

9. Plant Maintenance See Item 6 above.

10. Lessons Learr.ed Category A

• Items Implementation of LL Item 2.1.1 will provide-additional assur-ance that pressurizer heaters can be operated, that the pressur-izer, relief valve can be closed and/or isolated, and that t

pressurizer level indication is available. Each of these sercas

' to assure that primary system conditions can be controlled to reduce the ~ likelihood of the loss of natural circulation. Iccie-mentation of LL Item 2.1.2 will provide additional assurance -hat b

-- ei e 4 -,,e -

.=-=-----e.s a

~ *

.a a pressurizer relief or safety valve will not stick open and 50 ten- -

tially result. in natural circulation being interrupted. Imols .en-

- tation of LL Item 2.1.3.a will provide ~ additional . assurance that in the event of a pressurizer relief or safety valve sticking open this condition can be recognized and action taken to reduce -

the likelihood of the loss o'f natural circulation. Icolementa tion of LL Item 2.1.3.6 will provide additional assurance that opera-ting personnel can recognize a condition of imminent inadecua e core cooling and take timely action to reduce the likelihood of the loss of natural circulation. With regard to LL Items 2.1.7.a and 2.1.7.b, see Item 1 above. Implementation of LL Item 2.1.9 ,

will provide additional assurance that o:eratin; cersennel ci-properly diagncsa ard Occrectly resocr<d : un?.r.-icioe s: s'.5- ' - - :

which could result in a loss of natural circula- :n .; n.cu:e - :

likelihood of su n in c sry e.

11. Small Brear . ns'ysis anc procedures See Item 4 above. ,

(B) " Status Report on the Evaluation of Licensee's Compliance with the NRC Order dated August 9,1979 Metropolitan Edison Company, et al

- Three Mile Island Nuclear Station Unit 1. Docket No. 50-229", January 11, 1980.

( C,) None.

(0) See' introductory com.ents.

(E) See introductory comments. ,

Interrocatory Nos. 182-184 Licensee has objected to these interrogatories.

Interrogatorv No. 185 In response to UCS Interrogatory #46, the licensee states that failure of power operated relief valves, associated block valves, instruments and controls cannot aggravate the 4 consequences of a LOCA beyond that " submitted in the referenced analysis." The refer.enced analysis are primarily pre-TMI. '

Is it the licensees position that the consequences of the accident at TMI-2 were not "beyond that submitted in the refer-enced analysis?"

l e

e memswm tw

Response

(A) No. It is the licensee's position that the consequences to the ~

core of the accident at TMI-2 were beyond those submitted in the referenced analysis.

(B) None.

(C) None.

(D) See introductory contents.

(.) See introductory comments.

Interrogatory No.186 If this is not the licensee's position, identify which specific failures wjg3L the cause of consequences "beyond t, hat submitted in the referenced analysis."

Response

The referenced analysis relies upon operation of the ECCS to provide adequate water for core cooling.

Interrogatory No.187

'shich of the short and/or long term measures will prevent future accidents in which the consequences are "beyond that submitted in the referenced hnalysis?"

Response

(A) The Staff's recommended short and long term measures, listed in the Commission's Order of August 9,1979, are directed at preventing the recurrence of or mitigating events similar to those associated with the TMI-2' accident. They will therefore reduce the likelihood of a future accident in which the consequences are beyond that submitted in applicable analyses.

(B) " Status Report on the Evaluation of Licensee's Compliance with the NRC Order Dated August 9,1979 Metropolitan Edison Company, et al Three Mile Island Nuclear Station Unit 1 Docket No. 50-289,"

January 11, 1980.

(C) None.

(D) See introductory comments.

(E) See introductory comments.

4

== - . - - - . w w r.w., _,w_ u

_w,%%. ,.

Interroaatory No. 188 With respect to UCS Interrogatory No. 69, is it the licensee's position .

that the provisions of IEEE 279, S 4.8, as incorporated in 10 CFR 50.55a (h) do not apply to TMI-l? If this is,your position, explain it fully.

Response

(A) No. It is the licensee's position that IEEE 279 as incorporated in 10 CFR 50.55a (h) applies to the protection systems, as defined in IEEE 279.

(B) 1. 10.CFR 50.55a.(h).

2. IEEE 279-1968

3. Responses to UCS Interrogatories No. 68 and 69 (C) None.

(D) See introductory c. nants.

(E) See introductory comments.

Respectfully submitted, SHAW, PITTMAN, POTTS & TROWBRIDGE By Anu Mh' GdpVge 7. TrowbVidge u

j/

Dated: March 31, 1980.

l 9

4 SHAw, PITTMAN. POTTS & IROWBRIDGE

~

1800 M STR E ET, N. W.

WASHINGTON, D. C. 20036 Tt S ST E *M E N e.MuTTLEn saoas ase.Aeoo mAMSAv STEuAmT L.p o.poTTMAN wiNTMaos N. emowN _

otomoE r. Teowsmioot JAMES e.MAMvN STEpMEN O.poTTS mosEm? E. zaMLER QEmALD CMamNOFF TELEcom Em RfCMANO E. GALEN PMttua o. so3TwiCa mCsEm? s. RomaiNS taoat ase.oesa e ase.freo

2. TIMOTMY M ANLON STEVEN M. LUCAS GECmot M. mooEmS. .m. M ATI A S F. TRAviESO OIA3 JOMN e. mMINE LANDEm VICTomeA J. pEmmlNS TELEJL emuCE w CMumCMtLL JOMN M.Q'NCILL.Je LESu E A. NtCMQiSON. Ja. J Af A E PSTIE N OO*IOO (EM# # *I '

M ARTIN D. R m ALL MAND L. ALLEN CA g (g

• S M AwLAw "

J. d E N DALL TIMOYMf 3. Mg emeOE alCManOLeEmo JAY E. S E LI SA e ETM M.#ENDLETON -

SantanA M. ROS SOTTI LUCT G. E LI A SOP GECpOC V ALLEN. JR. #AUL A. AAPLAN EOwAND e. CmCSLANO wM. enAOFORO REYNOLOS Mammf M. QLASS8'EGEL COUNSEL PRED A.uTTLE TMOM AS M McCOnMsCM FmED OmASNEm SUSAN O.FALASON N ATM ANIEL P. e n E C O wa. WILLS A M P.eAnn MAmN AUGENeuCK JCN N L. CAmm. JR.

E NN E ST L, eLAR E, Ja, PMI Lg 5 J, hamyET CARLETON S. JONES aCeEnf M. GQaOON TMOMAS A. SamTEm J EA N N E A. CALC E NCN JAMES M SunOER eame ANA J. MCmGEN s SMELDON J wCISCL eQNNIE S. GOTTUES JOHN A. McCULLQuGM ALFRED M.POSTELL J. PATRIC K MsCR ET SETM M. MOOGAs s AN JAMES TMOMAS LENMART S M EILA E.MeCAFFEmTV STEVEN L. M ELT1 E m DEuSSA A.nf00*Af CEAN Q.AUUCR M ENN ETM J. M AUTM AN JOMN ENGEL DAVIO LAwmENCE MILLER

. ? As-.m N o . March 31, 1980 Ellyn R. Weiss, Esq.

Attorney for the Union of Concerned Scientists Sheldon, Harmon & Weiss 1725 Eye Street, N.W. Suite 506 Washington, D.C. 20006 Re: Three Mile Island Unit 1 Docket No. 50-289 (Restart)

Dear Ellyn:

I enclose Licensee's responses to your second set of interrogatories. Copies of signed affidavits for these responses are not enclosed, but will be forwarded shortly.

Sin rely yours eo e F.

48 rowbridg Enclosure cc: Service List l

l

- _ . _ . _ . . . . _ . _ ._