IR 05000295/1993010
| ML20036A247 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 04/30/1993 |
| From: | Farber M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20036A245 | List: |
| References | |
| 50-295-93-10-EC, 50-304-93-10, EA-93-064, EA-93-64, NUDOCS 9305110006 | |
| Download: ML20036A247 (22) | |
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i U. S. NUCLEAR REGULATORY COMMISSION i
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REGION III
Report Nos.
50-295/93010(DRP);50-304/93010(DRP)
EA 93-064 Docket Nos.
50-295;50-304 License No.
DPR-39;DPR-48 Licensee:
Commonwealth Edison Company Opus West III 1400 Opus Place - Suite 300 Downers Grove, IL 60515 Meeting Conducted: April 16, 1993 Meeting Location:
Region III Office 799 Roosevelt Road Glen Ellyn, Illinois 60137 Type of Meeting:
Enforcement Conference Inspection Conducted:
Zion Nuclear Generating Station July 27, 1992 through March 23, 1993 Inspector:
R. B. Landsman M #hJ Approved By:
M. J. Fas6er, Chief
' Date Reactor Projects Section lA l
Meetina Summary Enforcement Conference on April 16. 1993 (Report Nos. 50-295/93010(DRP):50-304/93010(DRP)
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 the f ailure to exercise appropriate design controls in the opening of auxiliary building missile door 10-L to establish an external laundry f acility.
9305110006 930503 PDR ADOCK 05000295 G
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DETAILS 1.
Persons Present at Conference Commonwealth Edison Company (CECO)
R. Tuetken, Site Vice President T. Joyce, Station Manager D. Wozniak, Technical Superintendent R. Chrznowski, Technical Staff Supervisor R. Ward, Director Regulatory Performance K. Dickerson, Regulatory Assurance S. Rademaker, Technical Staff S. Stimac, Nuclear Licensing Administrator P. Smith, Safety Review Engineer M. Jackson, Compliance Administrator G. Beale, Regulatory Assurance M. Manning, Technical Staff J. Madden, Technical Staff U. S. Nuclear Reaulatory Commission i
H. Miller, Deputy Regional Administrator, RIII W. Forney, Deputy Director, DRP, RIII
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B. Berson, Regional Counsel, RIII R. DeFayette, EICS, RIII M. Farber, Chief, Section lA, DRP, RIII
- J. Luehman, OE
- C. Shiraki, Project Manager, NRR J. Smith, Senior Resident Inspector
- Denotes those who participated via telephone 2.
Enforcement Conference An enforcement conference was held in the NRC Region III Office on April 16, 1993. This conference was conducted as a result of the findings of an inspection conducted July 27, 1992 through March 23, 1993, in which apparent violations of NRC regulations were identified.
Inspection findings were documented in Inspection Report Nos.
295/93009(DRP);304/93009(DRP), transmitted to the licensee by letter dated April 2, 1993.
The purpose of this conference was to discuss the violations, root causes, contributing factors, and the licensee's corrective actions.
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During the enforcement conference, the licensee discussed the apparent violations. The licensee's presentatien covered the event investigation including a synopsis of the event, investigation results, safety.
significance, and corrective actions. A copy of the licensee's slide presentation is attached to this report.
Attachment: As stated
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Zion Station Auxiliary Building Door Enforcement Conference April 16,1993
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Zion Station Auxiliary Building Door Enforcement Conference April 16,1993
- Introduction D. Tuetken Chronology R. Chrzanowski Issue R. Chrzanowski Corrective Actions R. Chrzanowski Safety Significance R. Chrzanowski Conclusion T. Joyce l
Closing Comments D. Tuetken l
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O INTRODUCTION
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Chronology
- August 1989
- Construction of Laundry Facility to support Refueling Outage. Security posting
begins. Hose disconnect is required to close the doors and de-post the guard.
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- October 10,1990
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- Meeting held to determine the future of the Laundry Facility. The decision is made to keep the laundry onsite, but upgrade it by adding a modification for a penetration through the Auxiliary Building wall for hose connection and the addition of skirting to the trailers.
- November 21,1990
- Tech Staff submits a minor plant change request for addition of a penetration through the Auxiliary building wall.
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- November - December,1991
- New trailer installed under a work request. During the approval of the work request it is decided that this is not a modification. Operation for cleaning Protective Clothing and respirators begins on November 6,1991.
- December 21,1991
- Minor modification for the penetration is completed. Hoses are now run through the penetration.
- February 22,1992
- Door continually open with Security Officer present.
- April 7,1992
- A Temporary Alteration for the security alarm to be relocated to laundry trailer is approved. This will allow for the security guard to be permanently removed.
- April 18,1992
- The Temporary Alteration installation is complete. Laundry trailer is now alarmed.
- April 27,1992
- After discussion with NRC Rill Security, the security guard is permanently removed.
The trailer is now considered part of the ' Vital area".
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Chronology (continued)
Late July /Early August,1992 NRC raises a concem with the affects of the Laundry Trailers on Auxiliary Building
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Ventilation during various scenarios. The NRC questions whether a 50.59 exists for the laundry trailer installation. A 50.59 is located for the minor modification
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penetration of 1991 and is provided. No other 50.59 is located.
Early August 1992 Tech Staff is working on answering the concems.
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August 6,1992 l
NED PRA group provides Zion with a letter documenting their estimate of the
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probability of a significant release of radioactivity through the Auxiliary Building I
doors as of the result of a tomado to be 1.3 E-8.
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August 24,1992 Zon completes a 50.59 safety evaluation for continued operation with the Auxiliary
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Building Door (L-10) open and OOS through 10/6/92. The evaluation is promptly provided to the NRC.
August 26,1992 Regulatory Assurance issues commitments to track repairs to the Auxiliary Building
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Doors (L-10) and completion of a procedure for high winds /tomados to address concerns. Door repair commitment is due 9/15/92 and procedure commitment is due 9/30/92.
September 2,1992 Auxiliary Building Doors (L-10) are repaired and retumed to service.
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September 25,1992 AOP 8.4 "Tomado or Sustained High Wind Conditions"is approved.
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October / November,1992 NRC requests that Tech Staff perform a test to determine whether Auxiliary Building
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ventilation system can maintain -1/4" dp if trailer were removed and door remained open. During this time frame Tech Staff is engaged in supporting the Unit 2 outage.
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Chronology (continued)
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Week of November 15,1992
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NRC is informed that the test is scheduled for November 24,1992 at 2300.
November 24,1992
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The test is cancelled due to radiological work in the Fuel Handling Building that had the potential of spreading contamination during the test.
December 9,1992
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The test is performed with approximately 144 square feet opening through the car
shed door to the Fuel Handling Building. The test results indicated that the nominal
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- 1/4" dp could not be maintained. The 50.59 evaluation of 8/24/92 assumed the Auxiliary Building ventilation system would maintain - 1/4" dp should the trailer fall from the building as a result of an earthquake or tomado. The decision is made to leave the doors at L-10 half open versus full open, reducing the open cross-sectional area to approximately 72 square feet.
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December 15,1992
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The test is reperformed with approximately 72 square feet of door open. The dp was observed to steady at approximately -0.20" with the door open. These test
results were determined to be acceptable.
Week of January 12,1993
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NRC questions whether the test results of the December 9th test should be reportable. The CECO reportability manual and CFRs are consulted and it is determined that it is not reportable.
January 27,1993
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PlF is written to document the results of the Auxiliary Building Ventilation / Laundry
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Door.
March 23,1993
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NRC Inspection exits at 1300.
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Issue 1
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Issues:
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i Failure to perform a 50.59 evaluation before opening the door and setting up the
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Laundry Facility.
The 50.59 that was performed on August 24,1992 was inadequate.
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Background:
1989 - the 50.59 performance was identified to be weak.
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i Early 1991 - refresher training on 50.59's was provided to the System Engineers.
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August 1991 - 50.59 performance improvement was noted by the NRC, with examples of exceptional Safety Evaluations.
Fall 1992 - a 50.59 violation relating to a Temporary Alteration was identified by the NRC.
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Corrective actions were established and are in progress to review Temporary l
Alteration 50.59's and to perform an independent Audit of the quality of the l
Temporary Alteration 50.59's.
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i Prior to opening the Auxiliary Building door for the Laundry Operations a 50.59 was
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not performed.
The 50.59 performed on August 24,1992, primarily addressed the affects of Auxiliary Building Ventilation and included the following UFSAR sections:
UFSAR Section 9.4.3 Auxiliary Building Ventilation System UFSAR Section 2.3.2.1.5 Severe Weather UFSAR Section 2.5 Geology, Seismology and Geotechnical Engineering UFSAR Section 3.2 Classification of Structures, Component & Systems UFSAR Section 15.2.6 Loss of All AC Power to the Station Auxiliaries UFSAR Section 15.7 Radioactive Release from a Subsystem or Component.
Reg. Guide 1.76 Design Basis Tomado for Nuclear Power Plants ecG3.6
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i Issue 1 (continued}
An invalid assumption was made that the " Auxiliary Building Ventilation System, with 1 supply fan and 2 exhaust fans, can maintain a nominal -0.25" H2O with respect to the outside pressure with the North Auxiliary Building door ( L-10) open. This was made because when the Fuel Handling Building inner door was fully opened and the outer door was approximately 4-5 feet open, air was felt flowing into the Fuel Handling Building. However, the Control Room Delta P indication was not used to
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quantify the Delta R The affects of flooding were not addressed nor was the UFSAR section for flooding
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referenced.
Based on the Auxiliary Building door issue and the previous Temporary Alteration Safety Evaluation weakness, further corrective actions are required.
Root Cause: Knowledge Deficiency Less than adequate training was provided to determine when a 50.59 safety evaluation is required to be performed.
Frequency of refresher training to ensure that all the design basis assumptions are evaluated when performing 50.59's was inadequate.
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Corrective Actions:
The Technical Staff has been trained regarding this event, with emphasis placed on
the analysis of all applicable accidents assumed in the UFSAR.
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Further 50.59 enhancement training is planned for the System Engineers for later this summer, and will be conducted periodically.
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In addition to the System Engineers; Site Engineering, Operating Management and the Maintenance Work Analysts will receive the 50.59 training.
The 50.59 training will focus on what constitutes a design change and that the design basis needs to be identified to ensure that all accidents are fully evaluated.
Another OV Audit of the 50.59's will be completed to evaluate the effectiveness of the corrective actions.
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Issue 2 Issue:
Failure to incorporate design requirements into site procedures or the Technical Specifications.
Background:
UFSAR Section 2.4.5.3 titled " Protective Structures" states:
" Safety related equipment has been protected against loss of function from flooding in the event of a probable maximum surges by the following means:
"The two large doors in the Auxiliary Building are required by operating procedures to be normally closed."
The Auxiliary Building door L-10 should have been included in the Technical Specification Table 6.8-1.
The Annunciator Response Manual procedure for Auxiliary Building Pressure High has the Control Room " dispatch operator to check Aux. Bldg entrance doors".
However, flooding could occur without this alarm coming in.
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Root Cause:
Inadequate Procedure due to omission.
Corrective Action:
AOP-8.4 titled: " Tornado or Sustained High Wind Conditions" was approved on September 25,1992. It has since been enhanced to address the flooding concem and the verification that the exterior Auxiliary Building doors are closed, including door L-10.
The Flood Doors will be labeled to delineate closure requirements.
Technical Specifications Table 6.8-1 will be revised to properly identify the Flood Doors.
The Annunciator Response Manual Procedure will be enhanced to list the appropriate door.,
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Annex i
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Unit 1
30, -
30,L Containment
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Auxiliary Fuel Building
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Issue 3
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= lssue:
Failure to translate appropriate acceptance criteria into surveillance procedures and
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alarm setpoints.
- Position:
- The acceptance criteria in the Auxiliary Building differential pressure is based on:
The Auxiliary Building Ventilation System is designed to provide a continuous source of filtered, temperature conditioned, outdoor air to maintain a thermal environment in accordance with the maximum ambient temperature for operating equipment in the various area served by this system.
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Conditioned air is supplied to clean areas and is routed to areas of progressively greater contamination potential.
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Pressure differential control dampers are employed as required to maintain a nominal 1/4-inch negative pressure in potentially contaminated cubicles or pipe chases. This meets the Design Basis Requirements.
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. The GDC 60 does not require an Auxiliary Building Ventilation system to
control the release of radioactive materials from the general areas, under a postulated accident.
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i Issue 3 (continued)
The Control Room Annunciator high alarm setpoint is 0" H2O a'nd is adequate. If the alarm is received, it indicates that air flow may not be from clean areas into potentially contaminated areas and the Annunciator Response Manual directs actions to be taken to decrease the Auxiliary Building pressure.
The daily rounds has the acceptance criteria of 0" to -0.65" H2O and is adequate.
We agree that if the pressure is indicating 0" H20, the air flow may not be from clean areas into potentially contaminated areas.
The historical adherence to the procedure was adequate with the highest reading of-0.1" H20.
Corrective Action:
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PT-O, titled " Surveillance Checklist and Periodic Tests", Appendix G, " Operating Checksheet", Rev. 6 Une item 23 was revised to have the acceptance criteria from-0.1" to -0.65" H20. Having the Auxiliary Building acceptance criteria at a negative -
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pressure, air flow will be from clean areas to potentially contaminated areas.
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Issue 4 Issue:
Documentation of door failure and unsatisfactory test performance was not performed in accordance with Technical Specification 6.6 and ZAP 700-08.
= Background:
Until February 1992, door was closed daily.
Zon Administrative Procedure (ZAP 100-07) allows equipment failures to be documented in a work request or a PlF. Work request Z96739 had already been opened, therefore a PlF was not required.
In hindsight, a PIF would have better ensured resolution of the 50.59 issue.
A PlF was not prepared following the NRC inspector's identification of a potential problem because Zon believed a PlF was not required because his concems were being adequately addressed.
In hindsight, a PlF may have resolved the 50.59 issue.
- Following the December 9,1992 test, a written letter documenting the test results was written to the Technical Staff Supervisor.
- The Technical Staff Supervisor ensured that corrective actions were taken and the test was reperformed with satisfactory results.
. The NRC was provided a copy of the letter.
The reportability review conducted on January 12,1993, and subsequent reviews determined the event not to be reportable (10CFR50.73).
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Issue 4 (continued)
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l A Problem Identification form should have been initiated following the unsuccessful test of December 9.
A Problem Identification Form was initiated on January 27,1993.
Root Cause: Knowledge Deficiency
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- The System Engineer believed that the problem was with the expired 50.59 and felt that the letter notified the proper level of Station Management and he believed that the appropriate corrective actions would be taken.
Corrective Actions:
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- The requirements to initiate a PlF and the reasons behind the PlF Process were emphasized to the Technical Staff.
- The management expectation of writing PIF's for all events and problems continues to be reemphasized throughout the station by the Station Manager.
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Reportability Requirements o
Requirement:
10 CFR 50.73(a)(2)(ii)
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Any event or condition that results in the condition of the nuclear power plant, t
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including its principal safety baniers, being seriously degraded, or results in the
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nuclear power plant being:
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l (A) In an unanalyzed condition that significantly compromises plant safety,
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(B) in a condition that is outside the design basis of the plant, or
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emergency procedures.
Discussion:
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Flooding analyzed in the UFSAR (2.4-7):
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= "In the event the Auxiliary Building door (L-10), which is a normally locked
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door, was left open, significant quantities of water could enter the Auxiliary
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Building under postulated maximum seiche conditions. The amount of water
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j required to cause initial flooding of the Residual Heat Removal (RHR) pump motors (542 foot level) is approximately 496,000 gallons. Based upon the
l above flooding margin and the design provision discussed below, we have l
concluded the transient water level will not cause flooding which could
impair the operation of any safety related equipment."
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'l Auxiliary Building Ventilation System in UFSAR (9.4-6):
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The Auxiliary Building Ventilation System is designed to provide a continuous
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i source of filtered, temperature conditioned, outdoor air to maintain a thermal environment in accordance with the maximum ambient temperature for
operating equipment in the various areas served by this system....
Conditioned air is supplied to clean areas and is routed to areas of progressively greater contamination potential. Pressure differential control
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dampers are employed as required to maintain a nominal 1/4 -inch negative
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pressure in potentially contaminated cubicles or pipe chases.
Since the plant was within its design basis and not in an unanalyzed condition, then
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the plant operating and emergency procedures were adequate for this event.
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Reportability Requirements
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Requirement: 10 CFR 50.73(a)(2)(v)
Any Event or condition that alone could have prevented the fulfillment of the safety function of structures or systems that are needed to:
- (A) Shutdown the reactor and maintain it in a safe shutdown condition,
- (B) Remove residua! heat,
- (C) Control the release of radioactive material, or
- (D) Mitigate the consequences of an accident.
Conditions A and B clearly do not apply to this event.
Condition C does not apply because the cubicle dampers maintain cubicles at nominal.25" H2O negative pressure between cubicle and general Auxiliary Building.
Also, Auxiliary Building Ventilation always had air flow from clean areas to potentially contaminated areas and therefore no unmonitored release would have occurred.
Condition D does not apply for the following reasons:
Door L-10 being opened did not render the Auxiliary Building Ventilation System inoperable. Therefore the ventilation system was able to mitigate the consequences of an accident.
- Door L-10 being opened is an analyzed condition for flooding.
During a tomado, door L-10 being opened has been evaluated and the missile hazard was found to be minimal.
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Issue 5
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Failure to take timely corrective action upon identification of the problems with the door.
Background:
Late July 1992 issue Identified August 61992 PRA evaluation received August 8 - 131992 1 A AFW pp inoperable August 241992 50.59 completed August 261992 Action Plan established September 21992 Door Operator Repaired September 25 1992 Procedure AOP 8.4 approved October 61992 50.59 expired November 121992 Start Z2R12 November 241992 Test postponed due to other ongoing work in the Fuel Handling Building.
December 91992 Test Completed 1/2 of Door L-10 was closed December 151992 Test successfully performed with 1/2 the door open.
Position: Zion Station does not believe that we were being untimely with the actions taken for this issue because:
-The PRA performed to support the 50.59 identified a very low probability event.
-The Safety Significance of the issue was minimal-The priorities were set commensurate with the Safety Significance.
-Communications with the NRC lead us to believe that priorities were consistant with NRC expectations.
-Looking back, the communications with the NRC were not as effective as they could have been.
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Safety Significance
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Scenario:
An inter-system LOCA with core damage must occur, such that fission products are released to the Auxiliary Building, and an environmental disaster such as a tomado
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or an earthquake must destroy the laundry trailers opening the Auxiliary Building to the atmosphere, and the Auxiliary Building must be at a positive pressure with
respect to the atmosphere.
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The possibility of these conditions occurring simultaneously is highly unlikely and beyond the Design Basis.
The UFSAR Section 2.4.5.1 has analyzed the flooding issue of door L-10 being left open, with the conclusion that flooding through this door could not impair the operation of any Safety Related Equipment.
i The potentially contaminated cubicles and pipe chase areas are maintained at a
nominal 1/4" negative pressure with respect to the clean areas of the Auxiliary
Building.
Tests here show that this area of the Auxiliary Building will maintain a negative pressure with respect to the atmosphere and air movement did flow from clean areas to potentially contaminated cubicles.
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Conclusion:
There was minimal safety significance due to these issues.
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Conclusion
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These events do not reflect the general performance at Zon Station.
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Safety significance of the situation was minimal.
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- The Auxiliary Building was capable of performing it's intended function and the Design j
Bases were met.
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- Continued focus on the 50.59 evaluations is necessary and will be provided.
Continued emphasis of the PlF procecc to all levels at the station is necessary and will be provided.
We believed at the time that we liad good communications with the NRC and understood
the priority of the issue.
Future verification of corrective action effectiveness will assure they are sufficient.
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