ML20236F416

Insp Rept 50-285/87-27 on 870923-1002.One Violation Noted. Major Areas Inspected:Instrument Air Sys

ML20236F416
Person / Time
Site:	Fort Calhoun
Issue date:	10/19/1987
From:	Harrell P, Reis T, Westerman T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
Shared Package
ML20236F382	List: ML20236F381 ML20236F416
References
50-285-87-27, NUDOCS 8711020132
Download: ML20236F416 (5)

See also: IR 05000285/1987027

Text

-

. ..

7:- -

+,

( ,

I

l

I

APPENDIX A

U.S. NUCLEAR REGULATORY COMMISSION

REGION IV

NRC Inspection Report: 50-285/87-27 License: DPR-40

Docket: 50-285

Licensee: Omaha Public Power District (0 PPD)

1623 Harney Street

Omaha, Nebraska 68102

Facility Name: Fort.Calhoun Station (FCS)

Inspection At: FCS, Blair, Nebraska

Inspection Conducted: September 23 through October 2, 1987

Inspectors: 7 h. M

P. H. Harrell, Senior Resident Reactor

/0-/4-F7

Date

Inspector

l' Y' & /c - / + - V 7

7. Reis, Resident Reactor Inspector Date

Approved: [' /'

T. F. Westerman, Chief, Projects Section 8

/ O - / 9 '8 7

Date

'

Inspection Summary

Inspection Conducted September 23 through October 2, 1987 (Report 50-285/87-27)

Areas Inspected: Routine, unannounced inspection of the instrument air system.

Results: One potential violation was identified (inoperability of emergency  !

diesel generators, paragraph 2).

I

!

i

o ,

I

- _ _ _ _ _ _ _ _ ____ -___ -__-___________ - __-_____ A

__

. : ,, w

-

i 4

[ 2

L

L j

DETAILS I

,

i

l

1. Persons Contacted i

OPPD

1

• R. Andrews, Division Manager, Nuclear Production

• W. Gates, Plant Manager

• C.~Brunnert, Supervisor, Operations Quality Assurance

• M. Core, Supervisor, Maintenance  ;

• T. Dexter, Supervisor, Security ';

• J. Fisicaro, Supervisor, Nuclear Regulatory and Industry Affairs

J. Foley, Supervisor, I&C and Electrical Field Maintenance  !

H. Faulhaber, Manager, Electrical Engineering,. Generation Station

Engineering

• J. Gasper, Manager, Administrative and Training Services

• L. Gundrum, Plant Licensing Engineer

• R. 'Jaworski, Section Manager, Technical Services

J. Kecy, Acting Reactor Engineer  :

R. Kellogg, Technical Services Engineer j

M. Klanderud, Licensing Engineer '

.L. Kusek, Supervisor, Operations

D. Munderloh, Plant Licensing Engineer

• T. McIvor,' Supervisor, Technical

R. Mueller, Plant Engineer

• A. Richard, Manager, Quality Assurance

G. Roach, Supervisor, Chemical and Radiation Protection

• R. Scofield, Supervisor, Outage Projects

• D. Trausch, Nuclear Production Engineer

S. Willrett, Supervisor, Administrative Services Security i

1

• Denotes attendance at the monthly exit interview. I

1

The NRC inspector also contacted other plant personnel including operators,

technicians, and administrative personnel.

2. Instrument Air System

On September 23, 1987, the licensee performed a regularly scheduled

surveillance test on Emergency Diesel Generator (EDG) 2 to prove

operability in accordance with Technical Specification (TS) 2.7

requirements. EDG 2 was loaded as specified in the test procedure and

approximately 9 minutes later the EDG tripped off due to high temperatures

in the engine cooling water system.

The licensee tagged out EDG 2 and performed trouble shooting activities to

determine the cause of the trip. As a result of the troubleshooting, the

licensee determined that the most likely cause of the event was the

_ _ _ - _ _ _ _ _ _ _

-- ._ -

'

%w .  ;

3

l

i

s

failure of the exhaust damper on the diesel radiator to open. Without the

damper open, no radiator. cooling air flow was available and the engine

cooling water temperatures increased. J

The licensee disassembled the air motor used for opening and closing the

radiator exhaust damper and found an accumulation.of water in the motor

air accumulator. They found that the pilot valve used to direct air into

the motor was coated with a gummy substance. The radiator exhaust damper

air motor' uses the plant instrument air system as a prime mover. The "

licensee, cleaned up and reassembled.the. air motor on EDG 2. Subsequent

testing on the EDG 2 damper indicated the damper operated satisfactorily.

Discussions continued between.the NRC resident inspector and the licensee, l

and on the' afternoon of September 23, 1987, the licensee decided to block i

the radiator exhaust damper for both EDGs open to ensure that the EDGs

would be available for operation should emergency onsite power be required

during an event.. Since the radiator exhaust damper on EDG 2 had failed to  !

operate on demand, no assurance could be provided that the damper on EDG 1 1

would operate,-if required.

The licensee subsequently disassembled the air motor on EDG 1 and found

similar circumstances as was noted with EDG 2 air motor. Water was found '

in the air accumulator and the internals of the air moter were also coated

with a gummy substance.

The plant instrument air system provides a supM y of air to the dampers on

each diesel via a common header. During July 1987, while performing a

surveillance test on the fire sydtem, water entered the instrument air

system through an interface between the air and fire water system. The

air was used as part of a " dry pipe" system in the fire main. When the

licensee realized that water had entered the instrument air system, a

systematic blowdown of the system air lines and accumulators was performed

to remove the water from the system. The air system blowdown was

established by review of the applicable piping drawings to determine the

accumulators and air piping risers to be checked for the presence of

water. However, the piping drawings did not show the installation of the

accumulators for the EDG air motors. For this reason, the air

accumulators were not checked for the presence of water. This oversight

resulted in the apparent failure of the damper on EDG 2 to operate on

demand. Water in the air system provided a potential common mode failure

due to the detrimental affects of the water on components designed to

operate using dry air.

TS 2.7 states, in part, that the reactor shall not be heated up or

maintained at temperatures above 300 F unless both diesel generators are

operable.

The Definitions section of the TS states, in part, that a component shall

be operable when it is capable of performing its specified function.

Implicit in this definition, shall be the assumption that all necessary

t

,

_ -. _.

.. - o ,

auxiliary equipment that are required for the component to perform its

function are also capable of performing their related support function.

Therefore, EDG 2 was considered to be inoperable in that auxiliary equipment,

the radiator exhaust damper, failed to perform its support function.

Also, no assurance,could be provided that the radiator exhaust damper for

~

EDG 1 would perform its support function due to both dampers being

susceptible to the common mode failure of water.in the instrument air

system. This is considered to be an apparent violation of NRC

requirements (285/8727-01). In. addition, potential weaknesses involving

the adequacy of the plant instrument air system design and the adequacy-

of the' licensee's corrective actions, once the problem was know to exist

in July 1987, need to be addrassed.

Subsequent to the failure of the EDG2 to operate on demand and discussions

with the NRC, the licensee continued to perform corrective actions _to

ensure that all the water was removed from the air system and to verify i

that all safety related components functioned normally, i

3. Exit Interview

The NRC inspectors met with Mr. R. L. Andrews (Division Manager - Nuclear

Production) and other members of the licensee staff at the_end of this

'

inspection. At this meeting, the NRC inspectors summarized the scope of

the inspection and the findings.

>

l

i

i

!

!

i

I

!

n --; ..

. ,

,

g,

- - a ,

,

,

W j. Y ,y. ~;1, .

-l 4 8 . rt - f. ;,, (I.5

l}

<

,

t

Y

'/

... ,

s

APPENDIX B n

.s x. . ,

x

PROPOSED ENFORCEMENT CONFERENCE AGENDA L

' OMAHA PUBLIC' POWER DISTE,CT

OCTOBER 29,19d7 x, >

I. Introduction and Purpose of Meeting <

'L. J. Callan

'

C Introduction of water into the instrument air ,e

system .

II. Licensee Presentation OPPD Staff-- a

Y.

III.'NRC Comments- L. J. Callan

-IV. ' Enforcement Policy D.'A. Powers

' '

V. Licensee Response (.0 PPD Staff

'

VI. Closing Comments L. J. Callan

,

t.

l

i -

/ ..,

, i f.

'

.I  %

.('

'

,

i!

! l l

k.I' j

,

'

\ j 'I ]?

-8 i j l '

?

I

'

)

l

l

I }

, /, 8

\. i

f l

A

s t

,

L -