ML18059A879

Forwards Response to Violations Noted in Insp Rept 50-255/93-26.Corrective Actions:Thermal Overload Settings for Four Engineered Safeguards Room Cooling Fans Reanalyzed, Revised & Tested

ML18059A879
Person / Time
Site:	Palisades
Issue date:	03/10/1994
From:	Rogers D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
EA-93-277, NUDOCS 9403160364
Download: ML18059A879 (9)

See also: IR 05000255/1993026

Text

consumers

Power l'OWERINli

NllCHlliAN'S

l'ROliRESS

Palisades

Nuclear Plant: 27780 Blue Star Memorial Highway, Covert, Ml 49043 March 10, 1994 Nuclear Regulatory

Commission

Document Control Desk Washington, DC 20555 David W. Rogers Plant Safety and Licensing

Director DOCKET 50-255 -LICENSE DPR-20 -PALISADES

PLANT -REPLY TO NOTICE OF VIOLATION

-NRC INSPECTION

REPORT No. 93026 NRC Inspection

Report No. 93026, dated November 24, 1993, forwarded

the results of a special unannounced

safety inspection

in the electrical

design control area. The inspection

report identified

an apparent violation

of NRC requirements

pertaining

to the operability

of engineered

safeguards

room cooler fans and containment

high pressure and containment

high radiation

actuation

relays. The NRC's February 9, 1994 letter contained

the Notice Of Violation

for these two situations.

• Our reply to the Notice of Violation

is provided in the attachment

to this letter. fl ()). f2rc ' ' v..-,1..J.(.\L David W .. Rogers Safety and Licensing

Administrator

CC Administrator, Region Ill, USNRC NRC Resident Inspector

-Palisades

Attachment

9403160364

940310 PDR ADOCK 05000255 Q PDR A CMS' ENERGY COMPANY

CONSUMERS

POWER COMPANY To the best of my knowledge, information

and belief, the contents of this submittal

are truthful and complete.

Sworn and subscribed

to before me this lQ_ day of __:.M-=a:..:....r=ch_,__

__ ' 1994. Le Ann Morse, Notary Public Berrien County, Michigan Acting in Buren County My commissjon

expires: February 4, 1997 [SEAL]

• ** ATTACHMENT

Consumers

Power Company Palisades

Plant Docket 50-255 REPLY TO NOTICE OF VIOLATION; . NRC INSPECTION

REPORT No. 93026 March 10, 1994 6 Pages

• • • * REPLY TO NOTICE OF VIOLATION

NRC VIOLATION

-INADEQUATE

DESIGN CONTROL MEASURES APPLIED TO CHANGE THE ENGINEERED

SAFEGUARDS

ROOM COOLER FAN MOTOR THERMAL OVERLOADS

I. 10 CFR Part 50, Appendix 8, Criterion

III requires in part that design control measures shall provide for verifying

or checking the adequacy of design, including

necessary

design reviews, calculational

methods, or performance

of a suitable testing program. Contrary to the above, on 3, 1993, the design control measures 1 * applied to change the engineered

safeguaPds

room cooler fah motor thermal overloads

were inadequate.

Specifically, the trip setpoints

were set at or below the normal operating

current and there was no adequate design review nor suitable testing to check the adequacy of the design. Consequently, during the period from May 16 to June 5, 1993, the reactor was critical with the safeguards

room cooler fans inoperable

and incapable

of performing

their design function.

This degraded the operability

of ECCS and containment

cooling equipment

such that those safety systems could not have performed

their intended function under certain conditions,_

in this case, absent prompt manual actions including*

trouble shooting and repairing

the engineered

safeguards

room cooler fan motor thermal overloads.

CPCo RESPONSE Admission

of the Violation

Consumers

Power Company agrees with the alleged violation

and has .Paid the civil penalty via letter -dated February 28, 1994. Reason for the Violation

The cause of the violation

is attributable

to (1) iriadequate

control,*

(2) failure to confirm a design assumption

in the calculation

which was used. as input to the setting specification, and (3) inadequate

post maintenance

testing. The analysis of this event is documented

in

Event Reports LER 93-008, submitted

September

24, 1993, and LER 93-008-01, submitted

• November 24, 1993. Corrective

Actions and Results Achieved A. The thermal overload settings for all four of the engineered

safeguards

room cooling fans were reanalyzed, revised, and tested. The new settings were implemented

using the specification

change process which received a multi-disciplinary

design review.

2 B. Eight other thermal overload setting changes had been made using a "T-Frame" criteria ("T-frame" motors with a service factor of 1.0 using a Cutler-Hammer

No. 789 relay). These setting changes were reviewed and it was found that the measured equipment

running current was sufficiently

below the overload setting. C. Additional

thermal overload setting changes and breaker changes made during 1993 (approximately

40), other than the twelve "T-Frame" motors mentioned

in corrective

steps A and B above, were reviewed to ensure appropriate

post maintenance

testing was

D. A review of all 480-volt safety related motors at Palisades

where thermal overload heaters are applied was completed

including

a

of running load amps (RLA). Adequate operability

margins were verified for each motor by comparing

the RLA at reduced voltage to the lowest possible heater trip setting. Safety related motor operated valves were not reviewed as part of this effort since the-thermal

overloads

for these motors are wired to annunciate

only, not to trip the motors. E. To provide confidence

in our setting specification

methodology, a circuit protective

device setting specification

was requested

from an independent

design engineering

organization

for the engineered

safeguards

room fan motors and for five other power circuit protection

schemes installed

in the plant. This independent

specification

for the engineered

safeguards

room fan motors confirmed

the preference

for Hl046(A) heaters which were ultimately

installed

as described

in A above. The independent

specifications

for the other protection

schemes identified

no other inadequate

settings or inappropriate

setting methodology.

F. All setting sheet changes after

2, 1993 are to be completed

using the specification

change procedures

of the plant modification

and design control process. Also effective

after November 2, 1993, specification

changes affecting

safety related equipment

or having the potential

for impact on plant availability, are to be submitted

to a multi-disciplinary

design review effort as is typically

conducted

for facility changes. The multi-disciplinary

design review requires a _dedicated

design review team meeting. The purpose of the meeting is to assure a collective

understanding

of design purpose, proposed configuration, and physical and functional

design requirements

to be verified and assures that proper verification

test methods are specified

for determining

operability.

G. Internal correspondence

with suggestions

and considerations

for appropriate

post maintenance

testing for implementation

of setting sheet changes was completed

and forwarded

to the Electrical

Maintenance

Department.

Administrative

Procedure

5.19, "Post Maintenance

Testing," Revision 2, dated February 11, 1994, incorporated

this guidance.

• H. Analyses were completed

which evaluated

the potential

effect on the safeguards

equipment

assuming the safeguards

room cooling fans failed to function during a postulated

accident.

The analysis indicates

that the effect of the loss of the engineered

safeguards

room cooling fans indicate that the temperatures

in the east and west safeguards

rooms would continue to rise during the post accident condition

following

the onset of recirculation

of the containment

sump. It takes several days for the environmental

qualification

temperature

of the most vulnerable

equipment

to be affected.

I. The results of a multi-discipline

review group's root cause analysis of this and other recent design deficiencies

was the subject of quarterly

technical

staff training for engineers

and work planners.

'The completed

training focused on the use of the formal design change process for implementing

plant changes such as changes to circuit protective

device. settings, the need to validate assumptions

used in design

as expected values of normal 'running current, and the need for valid and comprehensive

post modification

testing. Corrective

Action to Avoid Future Non-Compliance

A multi-discipline

group was formed to review this event and others involving

electrical

design or modification.

The multi-disciplinary

group identified

plant activities

that could result in the implementation

of design changes without proper design change controls.

In particular, the review of maintenance

and system engineering

activities

found that some activities

had been implemented

through the work order_process

which may be design changes. Operability

determinations

were performed

if safety related equipment

was affected.

However, these determinations

concluded

that existing plant conditions

are acceptable.

The possible design changes occurred in less than 1% of approximately

1350 work orders reviewed.

Longer term actions in the area of design control compliance

to avoid further violations

are ongoing and include the following:

A. Engineering

performance

improvement

initiatives

are being defined and scheduled.

These initiatives

reflect needed improvements

in the area of management

and leadership, prioritization

and planning, safety culture* and teamwork, assessment

and human performance.

These engineering

initiatives

are being integrated

into an overall Palisades

Performance

Improvement

Plan. 3 B. By June I, 1994 revisions

to appropriate

design control procedures

will be completed

outlining

the requirements

for a multi-disciplinary

design review for all modifications

affecting

safety related equipment

or having the potential

for impact on plant availability .

C. By October 1, 1994 a review of protective

device setting methodology

and setting sheet implementation

from a design control perspective

will be completed

to determine

if any other weaknesses

exist. Appropriate

changes to existing design controls and protective

device methodology

4 will be implemented

as required.

The effort will include the review of our system protection

setting methodology

by an experienced

engineering

consultant.

In addition, an engineering

design guidance document will.be* developed

for specifying

circuit protective

device settings.

Date of Full Compliance

Full compliance

has been achieved.

NRC VIOLATION

-INADEQUATE

DESIGN CONTROL MEASURES FOR THE SELECTION

AND REVIEW FOR SUITABILITY

OF PARTS, EQUIPMENT, AND PROCESSES

ESSENTIAL

TO SAFETY RELATED FUNCTIONS . II. 10 CFR 50, Appendix 8, Criterion

III, requires in part that design contro 1 measures sha 17 be established-for

the se 7ect ion and review for suitability

of application, of parts, equipment, and processes

essential

to safety related functions.

• * Contrary to the above, as of August 4, 1993, design control measures established

for the selection

and review for suitability

of parts, equipment, and processes

essential

to safety related functions

were* inadequate..

Specifica77y, in 1990 containment

high pressure and containment

high radiation

relays, equipment

essential

to safety related functions, were selected such that relays with nine or more normally closed contacts had an inadequately

sized closing coil for operation

under design conditions

involving

seismic events or minimum .,electrical

voltage. As a result, from the 1990 refueling

outage until August 4, 1993, the containment

h_igh pressure*

and containment

high radiation

actuation

systems were not capable of performing

their intended safety functions

under certain design basis conditions, i.e., seismic events or minimal electrical

voltage conditions.

CPCo RESPONSE ADMISSION

OF VIOLATION

Consumers

Power Company agrees with the alleged violation.

REASONS FOR VIOLATION

This violation

occurred as a result of an original plant design deficiency.

While it is true that improperly

qualified

relays were installed

in the containment

high pressure (CHP) and containment

high radiation (CHR) circuits during the 1990 refueling

outage, the newly installed

relays were the same model number relay and coil and the contacts were configured

the same as the existing original plant Gonstruction

relays. This deficiency

was perpetuated

by procurement

and installation

of identical

replacement

relays. The relay replacement

qualification, also, was not adequate.

Procurement

of safety related equipment

involves:

1. Identification

of critical design characteristics

2. Identification

of tests and/or analysis to verify that these critical design characteristics

are satisfied

3. Comparisqn

of test results to acceptance

criteria and/or review of analysis to ensure all critical design characteristics

have been met. * Procurement

of these relays failed to completely

identify all critical design characteristics

and, thus, system and component

interface

deficiencies

were not identified.

A contributing

cause was the

of mechanical

loading factor information

which would have identified*

the number of normally closed contacts as a critical.

design

5 However, if the relays had been tested in the configuration

in which they were to be installed

and proper acceptance

criteria had been identified, testing of the relay would have identified

the system/component

interface

defi ci enci es* .. The analysis of this event is documented

in Licensee Event Report LER 93-012, submitted

November 24, 1993. CORRECTIVE

ACTIONS AND RESULTS ACHIEVED 1. The original test relay was retested to ensure the CHP and CHR relays configured

with eight or less normally closed contacts would perform their function under all design

2. The original test relay tested with a more powerful coil . . installed

to ensure the CHP and CHR relays configured

with nine, ten or eleven normally closed contacts would perform their function under a 11 design parameters.

• 3. New more powerful coils were installed

in CHP and CHR relays configured

with nine, ten or eleven normally closed contacts.

4. A note was added to the CHP and CHR electrical

schematic

diagram to indicate which coil must be installed

depending

upon the configuration

of the relay: 5. Stock descriptions

and the equipment

data base for all CHP and CHR relays configured

with nine, teh or eleven normally closed contacts were revised to indicate these relays require the more powerful coil. 6 6. The vendor information

explaining

mechanical

loading was added to the controlled

vendor file. 7. Lessons learned training was conducted

for all systems, procurement

and chemistry

department

engineers.

Included in the training was the need to adequately

identify critical characteristics

and perform comprehensive

testing of the installed

configuration.

CORRECTIVE

ACTIONS TO BE TAKEN TO AVOID FURTHER NONCOMPLIANCE

I. Design control, maintenance

and procurement

procedures

are being reviewed and revised as necessary

to formalize

the determination

or review of critical characteristics.

2. Other convertible

pole relays used in safety related applications

are being identified

to determine

if any similar restrictions

apply. DATE OF FULL COMPLIANCE

Full compliance

has been achieved.