ML20198C456

Insp Rept 50-382/97-27 on 971117-1205.Violations Noted. Major Areas Inspected:Review of Licensee Identification That Plant Ventilation Sys Could Adversely Affect Level Indication for Refueling Water Storage Pool

ML20198C456
Person / Time
Site:	Waterford
Issue date:	01/02/1998
From:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
Shared Package
ML20198C423	List: ML20198C418 ML20198C443 ML20198C456
References
50-382-97-27, NUDOCS 9801070284
Download: ML20198C456 (6)

See also: IR 05000382/1997027

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ENCLOSURE.2 -

U.S. NUCLEAR REGULATORY COMMISSION

_ REGION IV

Docket No.: . 50-382

License No.:'- - NPF 38

Report No.: 50-382/97-27

Licensee: Entergy Operations, Inc.

Facility; Waterford Steam Electric Station, Unit 3  ;

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Location: Hwy.18 -

Killona, Louisiana

Datesi November 17 through December 5,1997

Inspector: G. A. Pick, Senior Project Engineer

Approved By:_ P H. Harrell, Chief, Project Branch D

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9901070284 990102

PDR ADOCK 05000382

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EXECUTIVE SUMMARY >

Waterford Steam Electric Station, Unit 3 - 4

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NRC Inspection Report 50-382/w?-27

This routine, announced inspection included a review of the licensee's identification that the '

plant ventilation system could adversely affect the levelindication for the refueling water storage

pool.

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Ooerations

- A violation was identified for failure to generate a condition report when an adverse

condition affected a safety-related system. (EA 97-277) (Section 08.1).

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-* Discretion was granted in accordance with Section Vll.B.3 of the Enforcement Policy

_ (old design issues) fo. .ailure to maintain an adequate design for the refueling water

storage pool level instrumentation (EA 97-277) (Section 08.2).

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Report Details j

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Summarv of Plant Status j

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- The plant operated at essentially 100 percent power during this inspection; j

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Miscellaneoua Operations issues - 1

^ Od.1 - (Closed) Unresolved item 50-382/9712-01: Failure to initiate a Condition Repod-

This item was initiated to review the circumstances related to a failure of operations

personnel to promptly initiate a condition report to document a potentially adverse .

interaction of the controlled ventilation area system with the refueling water storage pool

level instrumentation, which was identified on February 23,1997. Instead of generating .- .

- a condition report, a shift technical advisor requested design engineering to determine

whether the interaction of the ventilation system on the pool level indication had been

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included in establishing the setpoint for the recirculation actuation signal.- -;

On March 6, a shop meeting was held for instrumentation and control technicians.

' During this meeting, the shop foreman discussed the importance of the refueling water l

- storage pool and its role in' plant safety. As a result of this meeting, an instrumentation )

and control technician, present in the control room when the interaction between the ,

controlled ventilation area system and the pool instrumentation was identified, initiated *

Condition Report 97-0562, on March 8, to document the previously identified. .

nonconforming condition.

- The inspector established that, from about February 24 to March 8, numerous contacts

were made between the design engineering group and operations personnel in an

attempt to decide if a problem existed and, if so, what to do about it. During this period,

no apparent action was taken to perform a formal evaluation to determine the operability

status of the equipment supplied by the refueling water storage pool. It was not until a

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condition report was generated that a formal analysis was completed. This analysis

revealed that a potential existed for the injection and spray systems to be inoperable.

The details of the analysis and the results ootained are discussed in Sectbn 08.2 of this

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Procedure W2.501, " Corrective Action," defined an adversa condition, in part, as a

u ' deficiency that detracts from the safe operation of the facility and includes nonconforming e

conditions. A nonconforming condition is an adverse condition affecting a safety-related

' system caused by a deficiency in characteristic that renders the quality of the item

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indeterminate, ,

The inspector concluded that the failure of licensee personnel to promptly initiate a

condition report on February 24,1997, after identifying that the controlled ventilation area -

g - system affected the refueling water storage pool level instrumentation in an unknown

manner, is a violation (50-382/9727-01),

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08.2 (Closed) Unresolved item 50-382/9712-02: Evaluate Past Operability and Adequacy of

Corrective Actions Related to the Potential for Vortexing in the Refueling Water Storage

Pool

The inspector reviewed the past operability evaluation related to the effects of vortexing

(air ingestion) on the abihty of the injection (Iow and high pressure) and containment

spray pumps to perform their design function prior to transferring the pump suction from

the refueling water storage pool to the containment sump upon receipt of a recirculation

actuation signal. Specific to this review, the inspector assessed whether the vortexing

combined with the effects created by a plant vemi!ation system, as described in NRC

Inspection Report 50 382/97-12, rendered the injection and spray systems inoperable.

During a previous inspection from May 25-30,1997, the inspector reviewed the design

deficiency associated with the refueling water storage pool level instrumentation (refer to

NRC Inspection Report 50-382/97-12). This design potentially created a common mode

failure mechanism for allinjection and spray pumps. The licensee demonstrated that

sufficient conservatisms existed in the vortex calculation to ensure that the pumps

remained operable, as long as transfer from the refueling water storage pool to the

containment sump occurred at or above the 5.4 percent levelin the refueling water

storage pool.

The licensee also determined that, factoring in the total instrument loop uncertainty, main

condenser evacuation system effect, and worst-case ventilation system effects, the

setpoint for the recirculation actuation signal would be reduced from 10 to 4.86 percent,

which could have rendered the injection and spray systems inoperable. The licensee

removed conservatisms from the uncertainty calculation by using temperatures closer to

the actual accident temperatures. Specifically, the licensee used an ambient

temperature of 65'F instead of the original 60'F and an accident temperature of 115'F

instead of the original 150'F. These adjustments resulted in a new recirculation

actuation signal setpoint of 5.47 percent and demonstrated that the injection and spray

systems remained capable of performing their intended safety functions.

Concurrent with this evolving design issue, an NRC reviewer expressed concerns with

the methodology used by the licensee to determine the level for the onset of vortexing in

the condensate storago pool. The NRC reviewer was evaluating a Technical

Specification amendment requcst submitted by the licensee to raise the minimum

allowed levelin the condensate storage pool. As a result of the concerns identified by an

NRC reviewer, the licent.ee identified that the analytical methodology failed to account

for the continuous recirculation flow to the condensate storage pool, which established

eddies and increased the susceptib!'ity to vortexing. Additionally, the NRC reviewer

expressed concern because the licensee's methodology did not contain supporting test

data.

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The significance of this observation by the NRC reviewer was that the same

methodology was used by the licensee to determine when vortexing occurs for_ all

safety related tanks installed on site. The implication was that, if the licensee's

methodology had not properly determined when vortexing would occur in the '

condensate storage pool, then the determindion of when vortexing would occur in the

refueling water storage pool was also incc:r. ci Evaluation of the deficiency with the

licensee's calculational methodology and its sit,dcance are discussed in NRC

Inspection Report 50-382/97 24.

The inspector reviewed the evaluation completed by the licensee to address past

operability of the injection and spray systems, interviewed the engineer who performed

the operability evaluation, and assessed the engineering judgment used to conclude

that past operability was maintained. The inspector agreed with the conclusion that the

- injection and spray systems remained operable. This conclusion was reached in

consultation with the NRC reviewer that identified the original problem with the

calculation.

Because the licensee determined that the pumps remained operable, even though ,

vortexing would have occurred in the refueling water storage pool, the NRC determined <

that the ventilation affects on the refueling water stor6ge pool met the requirements for

discretion as specified in Section Vll.B.3 of the NRC Enforcement Policy. This section

discusses the enforcement action options available for the licensee's discovery of an  :

old, preexisting plant design issue. Specifically, the licensee identified that ventilation

affected the ability of the refueling water storage pool!o perform its safety function; the

problem was corrected during the last refueling outage when the licensee installed

cruciform vortex breakers and rerouted the instrument tubing to eliminate the ventilation

effects, as desribed in inspection Report 50-382/97-12; and it was not likely to be

identified by routine licensee efforts. As a result, this issue is being handled as a

. noncited violation (53-382/9727-02).

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>; X1 Exit Meeting Summary

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The inspector presented the inspection results to members of licensee management ,

during a formal telephonic exit on December 15,1997. The licensee acknowledged the

findings presented.~

LThe inspector asked the licensee whether any materials examined during the inspection

should be considered propriehry, No proprietary information was identified.

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ATTACHMENT

SUPPL.EMENTAL INFORMATION

PARTIAL LIST OF PERSONS CONTACTO

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Licensee

G. Bruner, Manager, Planning and Scheduling

F. J. Drummond, Director Site Support

C. M. Dugger, Vice-President, Operations .

E. C. Ewing, Director Nuclear Safety & Regulatory Affairs

C. Fugate, Operations Superintendent

T. J. Gaudet, Licensing Manager

J. G. Hoffpauir, Manager, Operations

T. R. Leonard, General Manager, Plant Operations

G. D. Pierce, Director of Quality

C. H. Thomas, Corporate Communications

D. W. Vinci, Superintendent, System Engineering

A. J. Wrape, Director, Design Engineering

INSPECTION PROCEDURES USED

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IP 92703: Onsite Followup of Events

' ITEMS OPENED, CLO55D, AND DISCUSSED

Ooened

50-382/9727-01 VIO Failure to initiate a condition report (Section 08.1)

50-382/9727-02 NCV inadequate design control for the RWSP level instrumentation

(Section 08.2)

Closed

50-382/9712-01 URI Failure to initiate a condition report (Section 08.1)

50-382/9712-02 URI Review operability of RWSP (Section 08.2)

50-382/9727-02 NCV Inadequate design control for the RWSP level instrumentation

(Section 08.2)

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