05000296/LER-1979-005-01, /01T-1:on 790506,BHR Water Supply Isolation to 2B RHR Heat Exchanger Isolated Standby Coolant Supply to Unit 3.Caused by Lack of Administrative Control Over Sys Cross Connect Valves.Administrative Controls Have Been Improved

/01T-1:on 790506,BHR Water Supply Isolation to 2B RHR Heat Exchanger Isolated Standby Coolant Supply to Unit 3.Caused by Lack of Administrative Control Over Sys Cross Connect Valves.Administrative Controls Have Been Improved

ML18024B102
Person / Time
Site:	Browns Ferry
Issue date:	11/13/1979
From:	TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML18024B101	List: 05000296/LER-1979-005-01, /01T-1:on 790506,BHR Water Supply Isolation to 2B RHR Heat Exchanger Isolated Standby Coolant Supply to Unit 3.Caused by Lack of Administrative Control Over Sys Cross Connect Valves.Administrative Controls Have Been Improved
References
LER-79-005-01T, LER-79-5-1T, NUDOCS 7911160396
Download: ML18024B102 (4)

LER-1979-005, /01T-1:on 790506,BHR Water Supply Isolation to 2B RHR Heat Exchanger Isolated Standby Coolant Supply to Unit 3.Caused by Lack of Administrative Control Over Sys Cross Connect Valves.Administrative Controls Have Been Improved

Event date:
Report date:
2961979005R01 - NRC Website

text

e Update Report Previo eport Date 5/lg/79 L(CENSEE EVENT REPORT 3

U.

CLEAR REGULATORY COMMISSION [oat 7

8 CON'T

~O 7

8 CONTROL BLOCK:

I A

L B

R F

9 LICfNSEE CODE

,Q 3Q20 0-14 15 (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 0

0 0

Q3 4

1 1

1 1 OR~OR LICENSE NUMBER 25 26 LICENSE TYPE 30 57 CAT 58 9

QB 1

1 1

3 7

9 QB 74 75 REPORT DATE 80

'to the 2B R

eat soURcE L~JQB 0

5 0

0 0

2 9

6 Q7 0

5 0

6 7

60 61 DOCKET NUMBER 68 69 EVENT DATE EVENT DESCRIPTION AND PROBABLE CONSEQUENCES Q10 Durin normal unit 3 o eration the RHR service water su

~O3 changer was isolated for maintenance.

The isolation of the water su 1

also isolated the standb coolant su 1

to unit 3.

T.

S. 3.5.C.3 and 3.5.C.5 There was no

~os hazard to the public health or sachet

Previous occurrences

None.

~OG

~OB 80 7

8 SYSTEM

CAUSE

CAUSE COMI.

VALVE CODE CODE SUBCODE COMPONENT CODE, SUBCODE SUBCODE

~CF QII 0

Q<3

~A Q<3 E

Z E

Z 0

E Q<4

~C Q<5

~Z Q<3 7

8 9

10 11 12 13 18 19 20 SEQUENTIAL OCCURRENCE REPORT REVISION LEA(AO EVENT YEAR REPORT No.

CODE TYPE NO, QI<

3 <RR3< ~79

~

~00 5

~~

~0, 1

~Z LJ

~1 21 22 23 24 26 27 28 29 30 31 32 ACTION FUTURE EFFECT SHUTDOWN ATTACHMENT NPAD 4 PRIME CQIJP.

COMPONENT TAKFII ACTION ON PLANT METHOD HOURS Q22 SUBMITTED FORM DUB.

SUPPLIER MANUCACTUAFH Q(B ~GQIB

~ZQ20

~ZQ2(

0 0

~~

Q23

~NQ24

~L Q25 Z

9 9

9 Q2G 33 34 35 36 37 40 41'2 43 44 4I CAUSE DESCRIPTION AND CORRECTIVE ACTIONS Q2/

The isolation of the unit 3 water su 1

durin u

lack of administrative control over system cross connect valves.

Uon s

the error, RHR heat exchanger 2B was returned to service within four hours and the 3

4 water supply restored.

Administrative controls have been im roved.

Installation of a redundant supply to standby coolant is planned for unit 3 1980 outa e.

80 OZ LJO<3 ~033 8

9 10 12 13 44 ACTIVITY CONTENT RELEASEO OF RELEASE AMOUNTOF ACTIVITY~4 CaB '33 '34 7

8

<J 10 11 44 PEIISONNC L fXPOSURES Nl<IJII( H I YPC 0('SCRIII(ION QSI

~oo CJQII Z

Q3II NA I

8

'I 11 12 13 PLHSIIJNNEI. INJUHILS NUMIIEH DLSCIIIP(IONQ41

~~oo oO EA METHOD OF DISCOVERY DISCOVERY DESCRIPTION Q32

~BQ3(

Operator Inspection Tour 45 46 LOCATIONOF RELEASE Q 45 80 80 ll0 7

8 O

7 8

9 11 12 Lo"S OF OH DAMAGE TO FACILITYQ43 TYPE

DESCRIPTION

~ZQ42 NA 9

10 PUBLICITY ISSUED OESCAIPTIONPJ

~NQ<<NA 9

10 NAME OF PREPARER 80 80 NRC USE QN( Y GB 69 PHONE 0a 2>>i(.60

Tennes.

ee Valley Autho)ity Dro)vns Ferry Nuclear Plant LER SUPE'LENENTAL 'NFORblA'J'ECN BFEEO-~0- ~6 /

795 Rl Technical Specification E>>volved 3.5.C.3 and 3.5.C.5 Repo) teil Under Technical Specification 6.7.2.A.2 Date of Occur) ence 5/6/79 Time of Occurrenc'300 Unit Ed:n))Ãication and Desi'.: iE)tion of Occu))'en<<e:

The RHR service water supply to the 2B RHR heat exchanger was isolated for maintenance.

The isolation of the water supply also isolated the standby coolant supply to unit 3.

Co))d)(lot)'.: I )'ior to Occu>".,'()nce:

Unit 2 refueling outage in progress.

Unit 3 operating normally at 75% power.

Action specified in the Technics! Spccil'ication Surveilla))c>>

Reqt) re)nent:> met du>>

to i))oL)erable eclu~iment.

Describe.

Place the unit in cold shutdown within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

A~i)trent Cause of Occur) ence:

The isolation of the water suPPly for maintenance was the direct cause;

however, lack of administrative controls over cross connect valves was the proximate cause of the accident.

At')alvs)s of Occul)'et)ce:

There was no hazard to the public health or safety.

< o')

< '))v 'i-'tii~n: Upon discovery of the standby coolant supply isolation action was immediately taken to restore the heat exchanger and the standby coolant was returned to service in four hours.

The standby coolant supply valve was painted a distinctive color and strict administrative controls imposed on its operation.

Installation of a redundant supply to standby coolant is planned but cannot be installed until the fall 1980 unit 3 outage because of design and material delivery schedules.

f'))llui" E.)

)'<'.'one previous.

~ l~t..))lien:

/Pe)'iod - l.ifetimc; Eke<;)ons!bility - AdministrativE'upe) v).

0)'Ri"nisi

>n

'v

-~ 's 4