Text

Enforcement Conference Repts 50-456/96-16 & 50-457/96-16 on 970514 in Lisle,Il.Major Areas Discussed:Apparent Violations Identified During Inspection,Along W/Corrective Actions Taken or Planned by Licensee
	ML20141H443
Person / Time
Site:	Braidwood
Issue date:	05/19/1997
From:	; NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:	;
Shared Package
ML20141H415	List: ML20141H411; ML20141H443;
References
	50-456-96-16-EC, 50-457-96-16, NUDOCS 9705230305
	Download: ML20141H443 (25)
	v • d • e

. . .

- .

. . . . . -.

. - .

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

. -

. . .

.

. . - . - . - .

l

!

l.

8

P

l-

i

U. S. NUCLEAR REGULATORY. COMMISSION

]

i

REGION lil

Docket Nos:

50-456;50-457

]

Licenses No:

NPF-72; NPF-77

'

1

Licensee:

Commonwealth Edison Company t

j

Facility:

Braidwood Generating Station

l;

Date:

May 14,1997

,-

,

L

Meeting Location:

Region ill Office

1

801 Warrenville Road

!

Lisle, IL - 60532-4351

-

Type of Meeting:

Predecisional Enforcement Conference

,

J

1

Inspection:

Braidwood Station

October 13,1996 - March 31, ? 997

.

l

Inspectors:

Darrell Schrum, Reactor Engineer

- Doris Chyu, Reactor Engineer

l

.

Approved by:

Rolf A. Westberg, Acting Chief

Engineering Specialist Branch 2

,

Division of Reactor Safety -

-

Meetina Summary

Predecisional Enforcement Conference on May 14.1997

Areas Discussed: Apparent violations identified during the inspection were discussed,

along with the corrective actions taken or planned by the licensee. The apparent violations

- involved: _1) Examples of inadequate separation of cables associated with redundant safe -

(

shutdown trains. (2) Failure of auxiliary building roll-up doors to satisfy the Appendix R 3-

hour fire barrier requirement.

I

i

I

i

,

!

<

9705230305 970519

E

PDR

ADOCK 05000456

6

O

PDR

'l

a

, _ . .

.- - ,

.

. ,

. . .

.

-

-.

. - -

.-

l

.

!

!'

Reoort Details

l

l.

' Persons Present at Conference

,

I.

-

.Gommonwealth Edison Comoany (Comed)

l-

l'-

T. Maiman, Senior Vice President

(

H. Stanley, Site Vice President

L

T. Tulon, Plant General Manager'

.

'

T. Simpkin, Regulatory Assurance Manager

.j

J. Meister, Engineering Manager

' U. S, Nuclear Reaulatory Commission

.

l'

A. B. Beach, Regional Administrator, Rlll

l

i

'J. Grobe, Deputy. Director, Division of Reactor Safety

1

l

R.' Gardner, Deputy Director, Division of Reactor Projects

l

l-

G.' Dick, NRR

i

P. Madden, NRR

l

R. Westberg, Chief, Engineering Specialist Branch 2

'

R. Lanksbury, Chief, Projects Branch 3

l

'

-

D. Schrum, Reactor Engineer

'

f

K. Selburg, Radiation Specialist

i

[

' 11.

.Predecisiona! Enforcement Conference

)

A Predecisional Enforcement Conference was held in the NRC Region ill Office on

j

May 14,1997. This conference was conducted as a result of the findings of an --

1

,

inspection conducted October 13,1996, through March 31,1997, in which five

I

'

apparent violations of NRC regulations were identified. The inspection findings '

i

were documented in inspection Reports No. 50-456/96016(DRS);

j

"

50-457/96016(DRS) transmitted to the licensee by letter dated March 31,1997.

The purpose of this conference was to' discuss the apparent violations, root causes,

contributing factors, and the licensee's corrective actions. In addition, the licensee

discussed actions to prevent recurrence of the apparent violations.

During the Predecisional Enforcement Conference, the licensee acknowledged the

apparent violations. The licensee's presentation included a synopsis of the apparent

l

violations, investigation results, safety significance, and corrr;ctive actions. A copy

l

of the licensee's handout is attached to this report.

l

L

During the Predecisional Enforcement Conference members of the staff requested

additicnal information relative to the licensee's evaluation of credible fires affecting

the Unit 1 non-segregated bus duct area, fire zone 3.2A-1. This request is attached

L

to this report.

!

.

As stated

i

'

Attachments:

'

t

$

'

i

!

.

.--

-

.. -,. --

b

!i<

I

'

i!

I

! ,!

t ! !!

,!!

l

Ili!

!!ii

_

.

-

,

'

1

_

n

t

_

e

m

_

n

_

o

ec

_

it

r

_

a

o

e7

t

f

c

9

-

S

n

n9

,

d

E

e1

,

r

_

=

o

l

,

e4

_

o

a

1

f

n

, wo

ny a

oM

_

,

d

i

,,

C

,

i

s

_

a

i

_

c

_

r

e

_

B

_

J

_

I

-erl>

.

l

1

il

_

1

.

l

!

i!: '. j

!

ilt;i

,![:l,

t

k

i

l;

IfI

.

,

2

-

y

-

e

r

l

.

e

n

.

-

n

t

o

s

a

_

t

.

i

u

e

S

l

-

_

TM

e

-

_

n

_ mm

e

-

i

_

TJ

G

i

-

_

.

-

a

,w._,..

.

-

.

-

dn

=-;

.

ms

.

-

.

_

e

n

a

~

.

_

-

g

_-

.

~

._

_

.

-

n

.

A,

o

i

t

s

,

-

a

s

k

r

a

o

a

-

p

o

-

n

eD

m

-

o

S

e

p

__

t

e

u R

i

_

c

b

g

-

l

u

s

a

o

n

d

eCRi

o

u

s

r

t

s

o

l

n

s

C

I

.

li

,

'

-_-_ _ _

-

_

-__

_

__

.

-

.

Braidwood Approach

~

'

to Thermo-Lag

I

__,

_m=_

_

_

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

..

'

o Eliminate dependence on Thermo-Lag

,

'

Identified installations

j

Revised Safe Shutdown Analysis

j

Implemented design changes

e Implementation complete

i

.

t

'

3

!

l

. _ . ,

'

~ ~ ~

_ - - _ - - - - _ .

-

&

-

.

i

-

i

I

Cable Separation Issues

=- ~ r ee m w

e- -

-

e Identified deficiencies in Safe Shutdown

.

I

Analysis (SSA):

i

Miscellaneous electric equipment room (MEER)

j

supply fans

1 A emergency diesel generator

!

1 A essential service water pump

i

1B auxiliary feedwater pump

i

t

Control room ventilation / fire hazards panels for

both units

i

f

4

!

-

,

.

!

~

_

!

MEER Supply Fans

j

__________________ x2=----

.

e Cause:

'

Original SSA failed to recognize faults on

the power cable to one MCC fed from a

common breaker could also cause loss of

.

the other MCC

e Corrective Action:

l

Design changes were installed to power

the MCCs from different source breakers

i

'

5

)

I

i

.

!

-.-

- _ _ .

.

i

-

,

-

.

1A Emergency Diesel Generator

l

_ - - - _ =

_ _ = = = = . _

e Causes-

!

,

The original SSA failed to recognize the

'

critical safe shutdown function of the

i

<

l

current transformer and potential

!

transformer circuits

!

Incorrect SSA cable routing input

o Corrective Action:

!

Design changes were installed to reroute

j

the cables through different fire zones

i

-

.

- -

-1

-

,

..

-;

1A Essential Service Water Pump

i

1

,

- - _ _

. . . _ . . .

_ _ _ . . _ . _ . ,

. . . . . . . . . . . . . . . . . .

. . . . . . .

.. .

.

o Cause:

'

i

-

The requirement to protect the power

supply cable was not included on all design

documents (6' conduit unprotected)

!

e Corrective Action:

Design changes were installed to reroute

the power cable outside of the fire zone

!

.

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

-

.

-!

1B Auxiliary Feedwater Pump

___==,m=_=,,

,=,_ _

_ _

i

e Cause:

-

i

SSA did not consider the cables

i

f

e Corrective Action:

Design changes were installed to modify

the affected control circuit to allow pump

start from the emergency control panel

!

i

t

.

I

!

f

h

i

-

.-

- -

. ~

_

-

- - . -

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

-

,

.

Control Room Ventilation

!

uw.auwez;menswicuay6m&_m3393fai[: _

. [ [ ;5C. 9 _ di 25125 ZRMIM%Mak a:

n

.-x.

-

j

.

_

r

k

e Cause:

l

/

i

The original SSA failed to account for the

dampers failing in the closed position

i

e immediate Corrective Actions:

l

Shift briefing to discuss the system status and

!

potential fire consequences

>

.

Dedicated fire watch in two fire zones

'

l

i

I

!

l

i

!

'

!

9

l

!

l

i

.

-

>

____________

.

i

-

!

Control Room Ventilation

_-_ , _ y_ ,,

_,,

m._ _

e immediate Corrective Actions (continued):

F

,

Two zones made transient combustible and hot

i

1

work exclusion areas

Temporary procedures were implemented to

restore control room ventilation with outside air

flow

t

Control circuits were isolated for two fans

'

1

The Control Room Inaccessibility procedure was

reviewed and found acceptable

j

i

!

i

10

,

i

I

{

l

>

'

.

-

.

_ - - -

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

- . -

-

.

,

.

!

I

Control Room Ventilation

_ m.n.-n-:.,

n,wnww.nna,a++x~

. .;3;. maguymmmaa n. . .

.

..

!

,

1

e Corrective Actions:

'

Design changes were installed to provide

j

>

alternate power supplies to fire hazards

panels

Design change was installed to remove

one VC train from remote shutdown panel

j

i

Special procedure to restore VC

'

1

I

i

,

11

l

!

-

- -

.

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

h

"

>

j

Cable Separation

-

Generic Corrective Actions

i

.

,

-aasemameawemessuusss:gms:sAh :

s . . . .. E^t . ...... . .. ?%fT?iEIMGEGYM&Nwseek w . . . . . -

'

,

i

e Reconstitution of Safe Shutdown

'

Analysis

i

Component review

Cable selection

Cable rout.ing venfication

..

'

Area analysis

Procedure review

Fire protection report revisions

12

[

>

- -- - -

-

--- ---

-- ---

-

- - .

+. .

.

_

-

.

Cable Separation

-

Safety Significance

.

. a ma : a ge

- ---

e Additional analysis for 6 zones

.

determined that the operators had the

ability to achieve and maintain hot

standby

e MEER heatup analysis in process for

two fire zones

13

__

-

.

Control Room Heat L p with

~

Loss of Ventilation

..

_____y_,_

m,,,_, _m

,

l

e Control room temperature not expected to

,

exceed 1C0o F in first 30 minutes

e AEER temperature not expected to

exceed 106o F in first 30 minutes

e Temperatures after 1.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months not

expected to exceed 120o F

l

14

I

.

l

___ __-_--

.

Roll-up Door

.

Issue and Causes

i

_______mmm_,_ayyy____ _

!

r

e issue: Doors did not meet 3 hour3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months fire

'

barrier requirement

i

e Causes:

Door not adequate for application

Incorrect installation

a

No post modification test

Inadequate surveillance

Untimely response to failure

i

15

!

- -

- - -

- -

-

- -

.

..

!

- - - . -

- _ - _ - - _ _ _ - - _ _ - - - -

.

_

Roll-up Doors

Corrective Actions

i

-

_

____,

m_

my,____

.

1

i

.

!

e Doors closed / tagged

'

e Doors inspected / adjusted on Unit 1

(Unit 2 fall 1997) to ensure 3 hour3.472222e-5 days 8.333333e-4 hours 4.960317e-6 weeks 1.1415e-6 months

j

'

l

barrier when closed

1

l

e Design engineering ta.lgate

i

!

e Fire door modification closed with

i

specific controls for opening doors

'

1

t

i

16

[

t

!

f

-

l

- - ___-_ _--__--__-- _ _.-.-

.

t

l

.

>

!

-

$

!

Actions to Prevent Recurrence

______

_______

unessusumusum-sie v-,umeuww .i.u.e.x/vsaJ.-'

LJ J :. 4h .. J ,:wi.

's M' ,..- . . . . . . . . . . . . . . . .

-

s

[

o Reviewed all open mods

!

'

Identified 21 others

'

.

Updated 50.59 evaluations for 2

-

!

Developed schedules to close all

!

.

Modification status mee":ing to track closure

!

I

.

17

!

. -

-.

- .

- - - -

-

- - -

-

. .

.

>

__--- _ _ _ -

-

_ - _

.

& '

Closure Curve for Expedited

'

.

i

Open Modifications

~.nnwawammaarmswmm = .

.s

wnewsumLuawwn .

.

_ . -

,sasaerm+seen __ u___

25

.

,

,m

,

-.

.

,

,j f

qg

,

.m

a:t

>

,

<

~

37

' an ,.

"ae '

<

'

- <_ ~

<

>

s

.

_

,

b*

M,

~

20

~ '

'W

^

-

.

<

. . . .

,

~.-

<

^

,

,:4';.~

m

i.B

+ .<

'

>

.^

'

4:.

h,

.'.sA

^

~

_

ACTUAL

ys'1:;

.

Z

-

-'1

,

l

w

~

"

'

..:

i

11.

15

+ Projected

wp ['

-

15

Wn

^xd g:

s

x

~

s....

'

,

>.

~

se

.

g

_

s

,,,

a

4 m..x .

4D,

'

54J

1:g'3

3

,

.

Q

,

8:.mc.;-

,

2

10

-

~

x

t ~

10

~

->

".

.'

'

w

.

-

,

l

Z

c-

',

~

.

'

.

m,

^

j

w

.

~

_

.

-

s

.

l

'

5

^

5

-

'

.

.,

2

a

s

m;

~

.

,

'

,

.:x.

s*

'

>

s..

_ . :r

j

,,,

'

$' v)

s

>'

s<

. . , .

/

.

1

.p '.

-

.

Sc:;j ~ _

,

jfjp' g-;

[

5

!

..

i

!

.

m

.

O

-

0

-

.

,

.

>

l

Oct-96

Dec-96

Feb-97

Apr-97

Jun-97

Aug-97

Oct-97

Dec-97

l

MONTH

l

1

18

l

1

!

i

I

i

_._,.,.A

- - _ - - _ - .

,

.

!

.

>

t

Actions to Prevent Recurrence

l

_ _ _ _ _ _

-

,_ _

!

o Revised design change procedures

'

>

.

Requires evaluation if not tested within 30

days of installation

Monthly design change status report

!

e Surveillance procedure revised

j

!

I

r

!

19

l

.

. .

-

_

.

-.

.

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

i

-

.

Roll-up Doors

Related Issues

____m.

_ , m _ z m e ,_ _ _

'

i

e High Energy Line Break (HELB)

-

Roll-up doors were credited as a boundary

.

in the evaluation

Door performance data has been

j

incorporated into the evaluation

Open area and closure time do not affect

previous conclusions

l

,

i

f

i

20

l

t

i

+

-

.

D

1

Roll-up Doors

Safety Significance

m

______m

,

,.w*w mv*w:

- - _ -

~ <. nwrW5$pWh

-... ,

mss

,~ .

._

t

e Single credible fire will not disable

'

.

redundant equipment

1

!

.

!

i

!

.

!

i

21

!

>

i

!

. -

..

,

e

'

._m...~

_ ._ _ ._

~ _ _ __ __ _ _ _ _. _ _. ..___ _ . _ . _ .._

. , ... r

.

-

,

i

,

'

Request for information

Attachment 2

!

L

Comed BRAIDWOOD Gi ATiON EVAT,.UATION OF CREDIBLE FIRES AFFECTING THE

l

UNIT 1 NON-SEGREGATED Bl)lS UUCT AREA. FIRE ZONE 3.2A-1

1.

It is our understanding that the post-fire safe shutdown cables of concem are

separated by 30 feet horizontally and that the primary intervening combustibles are

cables in cable trays. Please describe the general configuration of these trays (e.g.,

cable loadings, tray construction, stacked or single tray arrangements).

L

2.

. Please describe the design of the fire detection system in this area. What type of

l

detectors are used in this area and is their placement in accordance with fire

protection industry codes and standards and the conditions of their UL listings.

-

3.

An automatic total flooding carbon dioxide suppression system is provided for this

i

!

area which is activated by cross-zoned fire detection. Is the system designed in

accordance with fire protection industry codes and standards. For example, are the

j

carbon dioxide discharge nozzles installed above the effective height of the .

combustibles in the room. If the system does not comply with the code please

,

address the system deviations?

'

Please explain the initial system discharge test that were done and under what

'

conditions they were done. Please explain the carbon dioxide concentrations

achieved at the various room heights and what the soak times were achieved during

this test? Is the room configuration, such as room ventilation and air leakage,'the

'

same as those identified during the system discharge test?

j

-4.'

. Your evaluation indicates that tests and events data have shown that IEEE 383

i

qualified cable both resists ignition and limits fire growth. Please explain the scope

and depth of these tests and explain how they are applicable to the configuration and

plant conditions in question?

'In support of your evaluation,'could you please provide these tests so that we could

independently assess their applicability.

5.-

The fire scenario modeled a T,0 gallon polyethylene waste container filled with paper

and cotton rags. Is this considered your administrative limit with regard to the amount

and type of transient combustibles allowed in this area? If no, how do justify that this

' fire scenario bounds transient related fire events in this area.

. 6.

Your evaluation identified that the ignition temperature of cables is 932*F. Can you

describe how you substantiated this as the ignition temperature for the various cables

used at Braidwood. Please describe the tests which were done to determine this

!

i'

temperature. In order to get a better understanding of your cable combustibility

please provide a reference to the test standards used and copies of the applicable

i

test reports which substantiates the overall flammability of the cables used at

!

Braidwood.

l

1

I

,r

-

m7

-4

-

e.

-

. . . ,

1

7.

Please explain why the heat-up time calculations for the MEER and the main control

room use different times (8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months versus 1 and 1/2 hour).

l

8.

Please explain why the heat-up time calculations for the MEER and the SEER use

l

different times.

l

9.

Please describe the layout of the turbine tube oil system and its relationship to these

rolling fire doors. In addition, please describe the fire protection features in the

turbine building and what their design functions are.

10.

With the ESF switch gear room doors open, do you have analysis and the confidence

that a turbine failure event resulting in a lube oil system failure (possibly 16,000

gallons of tube oil being discharged) and fire would not challenge reactor safety. If

you do how was radiant heat handled.

?

2

,

!

ML20141H443

Text

Navigation menu

Search