ML20198C456
| ML20198C456 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 01/02/1998 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20198C423 | List: |
| 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
ADOCK 05000382
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EXECUTIVE SUMMARY
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Waterford Steam Electric Station, Unit 3 -
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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
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- plant ventilation system could adversely affect the levelindication for the refueling water storage
pool.
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Ooerations
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A violation was identified for failure to generate a condition report when an adverse
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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
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_ (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
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Summarv of Plant Status
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- The plant operated at essentially 100 percent power during this inspection;
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l. Operations
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Miscellaneoua Operations issues -
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^ 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
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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
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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.-
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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
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- storage pool and its role in' plant safety. As a result of this meeting, an instrumentation
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- and control technician, present in the control room when the interaction between the
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controlled ventilation area system and the pool instrumentation was identified, initiated
Condition Report 97-0562, on March 8, to document the previously identified.
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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
condition report was generated that a formal analysis was completed. This analysis
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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
repod.
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Procedure W2.501, " Corrective Action," defined an adversa condition, in part, as a
' deficiency that detracts from the safe operation of the facility and includes nonconforming
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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,
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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
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- 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
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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
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vortexing would have occurred in the refueling water storage pool, the NRC determined
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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).
E.MADA9amentlkte. tin 9s
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Exit Meeting Summary
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The inspector presented the inspection results to members of licensee management
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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
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
Failure to initiate a condition report (Section 08.1)
50-382/9712-02
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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