IR 05000483/1987035

Enforcement Conference Rept 50-483/87-35 on 871110. Violations Noted.Major Areas Discussed:Condition in Which Mispositioned Flow Balancing Damper Affected Performance of One Train of Control Room Emergency Ventilation Sys

ML20236T422
Person / Time
Site:	Callaway
Issue date:	11/19/1987
From:	Hinds J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20236T413	List: IR 05000483/1987035 ML20236T411 ML20236T419
References
50-483-87-35-EC, NUDOCS 8712010224
Download: ML20236T422 (4)

Text

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t U.S. NUCLEAR REGULATORY COMMISSION

REGION III

' Report No.-50-483/87035(DRP)

Docket No. 50-483 License No. NPF-30-Licensee: Union Electric Compa:1y Post Office Box 149 - Mail Code 400-St. Louis, M0 63166 Facility Name: Callaway Plant, Unit 1

. Meeting At: Region III Office, Glen Ellyn, Illinois Meeting. Conducted: November 10, 1987

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. Approved By: . Hinds , J ief 11 19 87 Reactor Projccts,.Section 1A Date Inspection Summary Inspection on November 10, 1987 (Report No. 50-483/87035(DRP))

Areas Discussed: An enforcement conference conducted to discuss a condition in which a mispositioned flow balancing damper affected the performance of-one train of the Control Room Emergency Ventilation System (CREVS).

Results: Two violations (failure to perform an adequate preoperational test and failure to promptly correct, document, and report a condition adverse to quality) as reported in Inspection Re; o i: No. 50/87033(DRP).

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DETAILS 1. Meeting Attendees Union Electric Company G. L. Randolph, General Manager, Nuclear Operations W. R. Campbell, Manager, Nuclear Engineering A. P. Neuhalfen, Manager, Quality Assurance D. S. Hollabaugh, Supervising Engineer, Electrical Systems Nuclear Regulatory Commission - Region III C. J. Paperiello, Deputy Regional Administrator B. A. Berson, Regional Counsel J. M. itinds, Acting Chief, Reactor Projects Branch 1 M. M. Holzmer, Acting Chief, Reactor Projects Section 1A L. R. Greger, Chief, Facilities Radiation Protection Section, Division of Radiation Safety and Safeguards C. F. Gill, Senior Radiation Specialist W. H. Schultz, Enforcement Coordinator G. A. Van Sickle, Project Inspector, Section 1A B. H. Little, Senior Resident Inspector, Callaway (by phone)

Nuclear Regulatory Commission - NRR T. W. Alexion, Licensing Project Manager, Callaway R. Fell, Technical Reviewer, Plant Systems Branch 2. Enforcement Conference Details The enforcement conference was hald to discuss the circumstances surrounding a mispositioned flow balancing damper (GKD 0324), which affected the performance of one train of the Control Room Emergency Ventilation System (CREVS). This matter was described in Inspection Report (IR) No. 50-483/87033(DRP).

After the opening remarks, the NRC outlined the apparent violations associated with the mispositioned damper, as discussed in IR 8703 The NRC emphasized its concern that this adverse condition, which could

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have significantly affected GDC-19 calculations of the potential dose to control room personnel, did not generate sufficient attention to result in its prompt correctio The licensee began its presentation with a summary of events associated with control room pressurization tests, the discovery of the mispositioned damper, and the subsequent licensee response to the proble The chronology was essentially the same as that provided by IR 8703 The licensee acknowledged that it had exercised poor judgement in e initially deciding that the damper position had no impact on potential

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control room doses. This determination was based on the fact that the

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air flow through the damper does not. explicitly appear in GDC-19 calculations. The licensee also acknowledged that an incident report should have been issued immediately to document the condition, and that more timely corrective action should have been pursue ,

The licensee's root cause evaluation revealed no documents that identified work to be performed on the damper and no evidence that the damper's position had been inadvertently changed. A review of preoperational test results, however, did not show that the flow through damper GKD 0324 had been verified. There is thus some likelihood that the damper's position has been incorrect throughout the plant's operating life. The failure to verify the correct flow through the damper appears to be an isolated oversigh ,

The licensee identified the following corrective actions:

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Both CREVS trains were rebalance (During the rebalancing procedures, no other damper was found out of position.)

Additional guidance was issued for the initiation of incident report Dampers which are critical to the flow balances of engineered safety feature (ESF) ventilation systems are being marked and locked in '

position. These dampers will be indicated as " locked throttled" in appropriate procedure Preventive maintenance procedures have been initiated to verify the <

CREVS flow balance at three-year interval Involved personnel have been counseled on the importance of timely identification and resolution of significant deviations from  :

safety-related parameter l A review of preoperational test results for other ESF ventilation systems was conducte No similar discrepancies were discovere The NRC expressed a concern with systems other than ESF ventilation systems, and indicated that the licensee should be investigating whether other design parameters had been overlooked during preoperational testin The licensee stated that it was doing s The licensee closed its presentation with a discussion of the safety significance of the mispositioned damper. The licensee stated that the mispositioned damper alone would not have prevented the CREVS from limiting doses to control room personnel within GDC-19 criteria. In addition, even with an unpressurized control room (resulting from breached control room pressure boundary seals, a condition which existed simultaneously with the mispositioned damper - see IR No. 50-483/87023 (DRSS)), the CREVS was capable of maintaining doses within GDC-19 criteria. This determination was based on the worst as-measured containment leak rate; the licensee acknowledged that GDC-19 criteria would be exceeded in this case if the leak rate assumed in the Final Safety Analysis Report were use I

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The licensee concluded that the case of the mispositioned damper did not I warrant a Severity Level III violation on the basis of its small safety  !

significance and isolated r.ature. The senior NRC representative l acknowledged this view and stated that a determination of enforcement action was forthcomin _ _ _ . - - _ - _ _ _ _ _ _ _

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a U.S. NUCLEAR REGULATORY COMMISSION

REGION III

Report No. 50-483/87033(DRP)

Docket No. 50-483 License No. NPF-30 Licensee: Union Electric Company Post Office Box 149 - Mail Code 400 St. Louis, MO 63166 Facility Name: Callaway Plant, Unit 1

. Inspection At: Callaway Site, Steedman, Missouri Inspection Conducted: October 7-17, 1987 Inspector: B. H. Little Approved By:

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/1 !^/!8 7 g)I Re.actor M. Hinds, Chief Projects Section 1A Date Inspection Suminary Inspection on October 7-17, 1987 (Report No. 50-483/87033(DRP))

Areas Inspected: A special unannounced safety inspection by the Senior

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_ Resident Inspector regarding mispositioned balancing damper No. GKD 0324 of Control Room Emergency Ventilation System (CREVS) Train "B."

Results: Two apparent violations were identified (failure to perform an adequate preoperational test and failure to promptly correct, document, and report a' condition adverse to quality - Paragraph 2.b(2)). The appropriate enforcement action for these violations will be determined and communicated to the licensee by separate correspondenc I i

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. DETAILS

' Persons Contacted R. Affolter, Superintendent, Systems Engineering

• J. Blosser, Plant Manager

'*W. Campbell, Manager,. Nuclear Engineering D. Hollabaugh, Supervising Engineer, Systems Engineering -

L. Kanuckel, Quality Assurance.(QA) Supervising Engineer-J. Laux, Superintendent,'.QA Technical Support K. Schweiss, System Engineer T. Sharkey, Supervisor, Compliance B. Standfield,.QA Engineer

• Denotes those present et one or more exit interview In addition, other members of the operations, compliance, and engineering staffs were contacte . Inspection of Control Room Emergency Ventilation System Operability Background During a.special' safety inspection from September 8-11, 1987, of a Licensee Event (LER 87-013-00) relating to inoperability of the CREVS, additional regulatory concerns were identified with regard'

to the position of CREVS Train B balancing damper No. GKD 032 While performing system flow checks to evaluate Control Room (CR)

pressure, the licensee found.that damper GKD 0324 had been positioned so.that the flow to Control Room Air Conditioning Unit Equipment Room (CRACUER) B was approximately 160 CF The licensee left the :)

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damper in the as-found condition upon completion of the flow check By design, the flow balancing damper provides manual regulation of supply air to the CRACUER (CREVS Train B). The CREVS, when-balanced in accordance with design (Bechtel Drawing No. M2H15210),

draws 300 CFM from the room and supplies a flow of 350 CFM through GKD 032 This balance maintains a positive pressure in the room j and thereby precludes inleakage from the Auxiliary Building in the j event of a design basis accident, and subsequent increased doses l to Control Room personne j

The inspector's concern relating to the position of the damper was discussed with the licensee at the close of the September 8-11 inspection and documented as Unresolved Items in NRC Inspection

. Report No. 50-483/87023(DRSS). '

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On October 5,1987, the licensee determined (based on a preliminary engineering evaluation of GDC-19 calculations) that the mispositioning of damper GKD 0324 adversely affected CREVS Train B functionalit The licensee documented this matter in Incident Report (IR) No.87-204 and notified the NRC using the Emergency Notification System (Four Hour Notification).

A special safety inspection was performed to assess the licensee activities associated with the mispositioning of CREVS Train B balancing damper GKD 032 The inspection included the following:

• Review of documentation: Request for Resolution (RFR)

No. 4210, irs87-173 and 87-204, Work Requests (WRs)

No. 104769 and No. 105377, Surveillance Procedure No. ESP-GK-03009, Preoperational Test Package No. CS-03-GK01, and Bechtel Drawing No. M2H1521 * Interviews with licensee personnel from the following departments: Compliance, Engineering, Operations and Quality Assuranc b. Inspection Findings (1) Event Chronology May 25, 1984 The CREVS preoperational test (CS-03-GK01)

was completed. Train A developed a Control Room positive pressure of 0.48 inches H2 O relative to the outside atmospher Train B developed

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a Control Room positive pressure of 0.26 inches H2 March 4, 1986 The 18-month Inservice Inspection was completed. Train A developed a CR positive pressure of 0.36 inches H 2 Train B developed a CR positive pressure of 0.62 inches H2 July 9, 1987 A CREVS surveillance test was performe Train A failed to develop a positive pressure > 0.25 inches H 2O due to breached electrical penetrations (IR No.87-122).

August 10, 1987 The licensee issued LER No. 87-013-00, which reported the inoperability of the CREVS and T/S 3.0.3 entry due to breached electrical penetration _ _ _ - _ _ _ _ - _ - _ _ _ - _

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August 14, 1997 While performing flow measurements (WR No. 104769) of CREVS Train B, utility personnel found damper GKD 0324 in a nearly closed positio The damper was left in this position, resulting in a flow of approximately 160 CFM to the CRACUE No IR was issue August 19, 1987 The licensee's Engineering Department initiated RFR 04210, which documented the concern of how CRACUER supply and exhaust flows affect Control Room pressure. A resolution need date of October 25, 1987, was indicated on the RF September 8-11, 1987 The NRC Region III inspection of LER 87-013-00 identified unresolved items relating to the position of damper GKD 032 September 10, 1987 The licensee issued IR No. 87-73, documenting the event of August 14, 1987 relating to the GKD 0324 damper positio September 12, 1987 The plant entered Mode 5 (Cold Shutdown).

October 5, 1987 The licensee issued IR No.87-204, based on the results of a preliminary engineering evaluation which determined that the mispositioned

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damper functionally degraded CREVS Train B and that Control Room operators would receive doses exceeding GDC-19 criteri The NRC was notified of the event via the ENS (Four Hour Report).

October 8, 1987 The balancing damper was correctly positioned during performance of a CREVS Train B flow balance per WR No. 10537 (2) Document Review and Evaluation of Events Chapter 9 of the SNUPPS Final Safety Analysis Report (FSAR)

provides a description of the CREVS. The system is designed to meet GDC-19 criteria. The FSAR does not describe the

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CRACUER flow / pressure requirement However, Bechtel Drawing '

No. M2H15210 specifies a supply' flow (controlled by damper-GKD 0324) of 350 CFM with a room exhaust flow of 300 CFM; therefore, the system is designed to maintain the room under a positive pressur Preoperational' Test Package CS-03-GK01 does not' provide-acceptance criteria pertaining to thelCRACUER air flowLgoverned by the GKD=0324 damper position. The. damper was not included on the sketches or damper lists which'were used in performance of the_ test. Air flows to'and from the room were not documented in the Preoperational Test. Package. .10 CFR Part 50, Appendix B, Criterion XI.(Test Control) requires.that test procedures.-

incorporate the requirements and acceptance limits' contained in applicable design. documents. The licensee's failure to-incorporate into test procedures the design flows for the CRACUER as specified in Bechtel Drawing No. M2H15210 is an apparent violation of 10 CFR 50, Appendix B, Criterion XI (483/87033-01(DRP)). ,

The surveillance requir'ements specified for Limiting Condition-for Operation 3.7.6 (which requires operability of both CREVS-trains in all modes) do not require initial or periodic verification of.CRACUER pressure or air flow. Periodic (once per 18 months) verification of CR pressure is required by Technical Specification (T/S) 4.7.6.e and is obtained during the performance of Surveillance Procedure ESP-GK-03009. The test was performed in March 1986. The test. data showed that CREVS Train B developed a CR positive pressure of 0.62 inches H2 0, which was a significant increase from the value (0.26 .

inches H2 O) obtained during the preoperational test performed in May 198 The CR pressure obtained during the 1986

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surveillance satisfied T/S requirements, and apparently no additional evaluation was performed. However, the increase in CR pressure indicated that a change had occurred in.CREVS Train B, possibly the result of the closing of damper GKD 032 The change occurred sometime following the 1984 preoperational test and prior to the 1986 surveillanc Through the review of plant records and personnel interview, the inspector was unable to determine when the balancing damper was mispositioned. The licensee's review of work documents found that no work-authorizing documents had been issued for GKD 032 The location of the damper (approximately 20 feet above the floor) makes it unlikely that it had been inadvertently mispositione The inspector could not rule out a damper position change due to air flow or vibration, as the damper could be moved by hand without loosening the wing nut, but it was found to be snu o____ _ _ _ _ _ _ _ _ _ _ _ ___________________________________________________]

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On August 14, 1987, while' performing CREVS flow measurements,.

utility personnel found Damper GKD 0324 in-a nearly closed

. position. L(The flow measurements:were in response to the-CREVS event involving breached electrical penetrations [LER No. 87-013-00] and the observed difference in CR pressure-during Train A and Train B. tests.) The system engineer was' involved in obtaining the flow measurements and was aware that the design supply flow specified for the CRACUER was 350 CFM (Bechtel Drawing No. M2H15210). Attempts made.to increase the flow-to the room caused pressure to decrease in the Control Room. The. damper was:left in the as-found position, providing a flow of approximately 160 CFM to.the -

CRACUER. .The action was taken based on a recognized need to maintain the T/S specified CR pressure. ' Based on the informal phone discussions between plant and corporate engineering staff members, the determination was made that the reduced flow to the CRACUER did not present an " operability" issue with regard to the CREV The shift supervisor placed a " hold" on per-formance of flow balancing (WR No. W104769). On August.19, 1987, the plant engineering staff' issued RFR No. 04210 to obtain formal resolution of this matter The RFR specified a need date of October 25, 1987. The mispositioned damper was not documented in an incident repor The inspector interviewed engineering personnel to assess the basis for the initial-engineering judgement (August 14, 1987)

that less than design flow to the CRACUER did not render the-CREVS Train B inoperable. It appears that the judgement was based on the following considerations:

• The FSAR does not address CRACUER Room pressure or air

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flow * T/S surveillance requirements do not specify periodic verification of CRACUER pressure or air. flow ~

• Preoperational Test CS-03-GK01 did not provide acceptance criteria relating to damper position, room pressure, or air flo * CRACUER conditions were not included in the CR dose calculations (GDC-19 criteria).

A review of the event chronology points out the licensee errors made following identification of the mispositioned damper. On August 14, 1987, while performing CREVS Train B flow measurements, utility personnel found balancing damper GKD 0324 mispositioned, resulting in reduced flow to the CRACUER. The as-found air

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l flow was approximately 160 CFM. Bechtel drawing M2H15210 l specifies a design flow of 350 CFM. Although damper adjust-I ments were attempted, the damper was left in approximately the as-found condition. The reduced flow through the damper

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represented a deviation from a design document and a' conditio adverse to quality. . The licensee's initial assessment of the

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degraded flow condition failed to adquately tscertain system functionality.and therefore'resulted in untimely corrective action. Additionally,. utility personnel failed to document the mispositioned damper on an incident report,; contrary to administrative procedure APA-ZZ-00500, " Nonconforming Operations Reporting and Corrective Actions." This matter was subsequently 4 documented in IR 87-173 on September 10,.1987, after the {

mispositioned damper was considered to be an, Unresolved Item by I an NRC Region-III inspecto ~

10 CFR 50,' Appendix B, Criterion XVI (Corrective Action) requires l

, that conditions adverse to quality be promptly identified and corrected, and that the conditions and associated corrective i actions be documented.and reported to appropriate levels of 1 managemen The licensee's failure to promptly correct, i document' and report the degraded flow condition resulting from

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the mispositioned damper is an apparent violation of 10 CFR 50, Appendix B, Criterion XVI (483/87033-02(DRP)).

On October 5, 1987, based'on the results of a preliminary engineering evaluation (RFR 04210 and IR No.87-173), the licensee determined that Train B of the CREVS had been-functionally degraded due to the incorrect position of balancing damper GKD 032 The licensee determined that this condition may have existed since the issuance of the operating license. Preliminary calculations showed that the dose to Control Room operators would exceed GDC-19' dose guideline Based on the findings of this inspection, Unresolved Items /87023-03 and 483/87023-04 are considered closed and will be tracked as the above cited violation . Licensee Corrective Action Balancing damper GKD 0324 was correctly positioned during performance of a complete CREVS Train B flow balance on October 8, 1987 (WR No. 105377).

A complete flow balance of Train A was also performed. No deficiencies were note The system engineer, engineering supervisor, and involved operations personnel have been counseled on the need for timely identification and resolution of significant changes to safety-related systems. The event will .be included in the required reading lis The event will undergo a review by the licensee's event evaluation team for evaluation of the root cause and corrective actio ____

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4. Safety Significance The Basis for Technical Specification 3.7.6 states, in part, that the .

operability of the Control Room Emergency Ventilation System ensures that the Control Room will remain habitable for operations personnel during and following all credible accident condition The licensee is obtaining a detailed safety evaluation from Bechtel Corporation to ascertain CREVS acceptability relative to GDC-19 criteri CREVS Train A was fully operable during the period that the Train B damper was mispositioned and would have provided associated protection to CR personnel, excepting periods when the CREVS was degraded due to breached electrical penetrations (June through July 1987) as reported in LER 87-013-00 and when Train A was removed from service for testing or maintenance. CREVS Train B was functional in all other respect The event posed no significant threat to public or plant safety based on the operability and capabilities of the redundant CREVS trains and the low probability of a design basis accident occurring at a time when both CREVS trains were in a degraded condition. However, the event increased the potential for unfiltered inleakage and an increase in dose to CR personnel, and is considered significant based on initial test performance deficiencies and untimely corrective action following deficiency identificatio . Exit Interview The inspector met with licensee representatives (denoted under Persons Contacted) at intervals during the inspection period. The inspector summarized the scope and findings of the inspection. The licensee representatives acknowledged the findings as reported herein. The j

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inspector also discussed the likely informational content of the '

inspection report with regard to documents or processes reviewed by the inspector during the inspectio The licensee did not identify any such documents / processes as proprietar I i

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