IR 05000254/1997013

Insp Repts 50-254/97-13 & 50-265/97-13 on 970731-0905. Violations Noted.Major Areas Inspected:Engineering

ML20217A382
Person / Time
Site:	Quad Cities
Issue date:	09/12/1997
From:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML20217A325	List: IR 05000254/1997013 ML20217A320 ML20217A366
References
50-254-97-13, 50-265-97-13, NUDOCS 9709190145
Download: ML20217A382 (9)

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U.S. NUCLEAR REGULATORY COMMISSION REGIONlli Dockets Nos: 50-254;50 265 l Licenses Nos: DPR 29; DPR 30 Reports No: 50 254/97013(DRS); 50 265/97013(DRS)

Licensee: Commonwealth Edison Company Facility: Quad Cities Nuclear Power Station Units 1 and 2 Location: 22710 206th Avenue North Cordova,IL 61242 Dates: July 31 - September 5,1997 Inspectors: R. Burrows, Reactor Engineer J. Guzman, Reactor Engineer Approved by: Mark A. Ring, Chief, Lead Engineers Branch Division of Reactor Safety J

9709190145 970912 PDR ADOCK 05000254 0 PDR

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EXECUTIVE SUMMARY Quad Cities Nuclear Power Plant, Units 1 and 2 NRC Inspection Report 50 254/97013(DRS); 50 265/97013(DRS)

This inspection included a review of the post modification testing of the residual heat removal service water (RHRSW) pumps regarding the cut-water and impeller modifications. The inspection also included a review of the inservice testing (IST) program related to the RHRSW pump *

No clearly documented basis existed for the licensee's RHRSW pump flow surveillance criteria, but the test criteria appeared to have technical merit. The inspectors concluded the pumps could meet their specified function with reasonable assurance (Section Ei.1).

• - The licensee's staff had been aware of a discrepancy between the RHRSW pump surveillance requirement and the UFSAR pump description since at least March 1997, but had not yet reconciled the differing values. This is, considered an unresolved item (Section E1.1).

The licensee's staff demonstrated weak engineering knowledge of the RHRSW system design basis (Section Ei.1).

• The licensee's self assessment identified good technicalissues related to the RHRSW pump testing but resolutiori was not technically rigorous or comprehensive. This is also f considered an unresolved item (Section E1.2).

The licensee did not have adequate controls to ensure the relocated RHRSW pump flow surveillance requirement was properly irnplemented in the IST program. The failure to incorporate applicable requirements and acceptance limits into the IST program was considered a violation of 10 CFR Part 50, Appendix B, Criterion XI (Section E1.3).

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Report Detaus likfd1ElatallI19 E1 Conduct of Engineering E1,1 Residual Hnat Removat Service Water (RHRSW) System Reauirements

, Insoection Scooe The inspectors performed a walkdown of the Unit i residual heat removal service water (RHRSW) system and interviewed the RHRSW system and design engineers. In addition, the inspectors reviewed documents related to the RHRSW plant design. A partiallisting of these documents is given at the end of this repor Observations and Findings The updated final safety analysis report (UFSAR) description of the RHRSW pumps indicated that the capacity was 3500 gpm with an approximate head of 760 ft (329 psig).

The pumps' surveillance requirement verified performance of at least 3500 gpm against a pressure of 198 psig. The system and design engineers stated that the UFSAR values were not concurrent requirements in that the UFSAR description meant that the pumps could deliver 3500 gpm and that the pumps could develop a head of (approximately) 760 ft (329 psig)in a throttled condition, but not both parameters at once. The inspectors questioned this response since the original vendor's pump curve and a recent contractor calculation (ODC 1000 M-0353, Rev. O) indicated that the pumps were designed to deliver 3500 gpm at a tothi developed head of 750 ft (325 psig).

The licensee also stated that the surveillance value of 198 psig originated from the design basis document (DBD-QC-008). The value in this document, however, was 470 ft (203 psig). The DBD basis calculation did not specifically support the 198 psig value either, These discussions led the inspectors to conclude that the licensee's staff did not clearly know the design basis or the accident analysis flow requirements for the RHRSW syste The licensee's staff stated that the measurement of the pump discharge pressure was conservative because the 198 psig was meant to be measured at the outlet of the RHR heat exchanger. The inspectors questioned this interpretation of the surveillance requirement as previous tests had measured the pressure upstream of the RHR heat exchanger at the pump discharge. The design engineer originated a problem identification form (PIF No. Q1977 03086) to ascertain the design basis pressure requirement coincident with the 3500 gpm requirement for the RHRSW pumps and the location where the pressure should be measure Further discussions with the licensee's staff and a subsequent review of the PlF operability evaluation resulted in the inspectors concluding that 3500 gpm flow with a pump discharge pressure of 198 psig was sufficient to provide the required flow rate during a design basis accident. This conclusion was supported by the inspectors'

evaluation of the PIF response based on the RHR discharge pressure at the heat

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exchanger inlet of 148 psig, a 30 psi drop across the heat exchanger, and a required differential pressure of 20 psig between the RHR and RHRSW sides of the heat exchanger. The PlF response stated that the design basis calculations and the UFSAR would be revised. The inspectors consider this issue an unresolved item (URI 50-254/97013-02a; 50 265/97013-02a) pending the licensee's final evaluation of the l UFSAR values for the RHRSW pumps.

Conclusions The licensee's RHRSW pump flow surveillance requirement appeared to have technical merit and demonstrated that the pumps could meet their specified function with reasonable assurance. However, the licensee's staff had not yet reconciled the discrepancy between the surveillance requirement and the UFSAR description and had been aware of this discrepancy since at least March 1997, in addition, the licensee's staff demonstrated weak engineering knowledge of the RHRSW system design basi E1.2 Testing Deficiencies a, insoection Scope The inspectors reviewed the results of various RHRSW pump modification work and test packages related to the cut water' and impeller' modifications, the latest RHRSW pump Inservice testing (IST) procedure and results, and RHRSW system drawings. The inspectors also interviewed the RHRSW design engineers and the IST coordinato Two recent NRC inspection reports (50-254/96017; 50-265/96017 and 50 254/96020; 50 265/96020) with examples of a violation of 10 CFR Part 50, Appendix B, Criterion XI,

' Test Control," were also reviewe Observations and Findings Calculation Deficiencies The inspectors noted a good design change self assessment audit (Core Team Review Assessment No.114 and PlF No. 97-1263) completed in March 1997, which identified severalimportant technical errors associated with post modification testing of the RHRSW pumps. These errors included:

• Net positive suction head was improperly determine *

Actual RHRSW pump flow extends beyond the original pump curve (approximately 3800 gpm vs. 3500 gpm required).

'The cut-water modification involved grinding the existing double volute inlet edges on the low pressure pum 'The impeller modifications involved increasing the impeller size on the low pressure pump and decreasing the impeller size on the high pressure pum .

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An operability evaluation was performed by the licensee to address these concerns and the system was found to be operable based primarily on calculations performed by contractors (QDC 1000 M 0353). The inspectors noted that the operability evaluation was lacking in several aspects. The licensee had not performed a rigorous review of the calculations used to support the evaluation. This was evidenced by the use of an incorrect value for the density of water at the assumed temperature and a -

nonconservative correction factor used to determine total developed head. In regard to the UFSAR discrepancy stated in Section E1.1, this calculation emphasized that seven out of eight RHRSW pumps did not meet the UFSAR description of 3500 gpm at approximately 760 ft (329 psig). This conclusion included the nonconservative correction facto The licensee had not considered this to be important or even realized the nonconservative nature of the calculation until the inspectors identifled these issue Had the licensee reviewed these calculations more closely, the fact that all eight of the RHRSW pumos, while meeting the surveillance flow requhment, could not meet the UFSAR description would have been discovered. The l',spectors consider this issue another example of an unresolved item (URI 50 254/97013 02b; 50 265/97013 02b)

pending the licensee's final evaluation of the UFSAR values for the RHRSW pumps. To address these NRC concerns, the licensee initiated another PlF (Q1977 03086).

Epst modification Testina Deficiencies The self assessment audit highlighted a significant problem with the method of measuring RHRSW pump flow for post modification testing. Upstream of the flow h

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element, flow is diverted to three additional flow paths: the RHRSW pump cubicle cooler, the control room refrigeration condensing unit, and the RHR motor oil cooler and pump seal cooler heat exchanger. During post modification testing these additional flows were not measured and were not controlled with specified valve lineups. A flow configuration under accident conditions that is different from the testing configuration could result in less conservative flow going to the RHR heat exchanger and would not verify the effectiveness of the modificatio Upon reviewing calculation QDC 1000-M-0353 and earlier test results and discussing this problem with the design engineer, the inspectors concluded that there was sufficient flow availabla to the RHR heat exchangers with all additional flow paths at maximum flow. The licensee stated that the calculations would be revised to address pos modification testing shortcoming JST Deficiencies The inspectors noted the same lack of rigorous flow control and measurement as explained in the post-modification testing deficiencies paragraph above. In this case the concern was the ability to repeat IST test conditions. Because the flow element is downstream of the pump discharge and the additional flow paths, identical measured flows could result in actual pump flows differing by approximately 200 - 300 gp Specifically, the lack of controls could have allowed the valves that isolate the flow to the control room refrigerator condensing unit to be in an unknown position. The licensee stated that the RHRSW pump IST procedure will be revised to control valve lineups to ensure test conditions are repeatabl . 1

, Condusion The licensee's staff self assessment identified good technicalissues related to the RHRSW pump testing but resolution was not technically rigorous or comprehensive. In addition, the inspectors concluded that the nonrigorous calculation review demonstrated a lack of a questioning attitude. The post-modification and IST discrepancies and the findings in a recent NRC inspection report (50 254/96020; 50 265/96020) indicated a continuing deficiency in control of testing configuration E RHRSW Surveillance Tests Insoection Scopa The inspectors reviewed the RHRSW pump flow :.urveillance requirement before and after the licensee incorporated the results of the Technical Specification Upgrade Program (TSUP). The inspectors also reviewed the RHRSW IST procedure and Interviewed the technical specification upgrade coordinator, the nuclear license administrator, and the IST coordinato Observations and Findinas On December 19,1995, via a safety evaluation report (SER), the licensee was given NRC approval to relocate the RHRSW pump flow surveillance requirements from the technical specifications te the IST program. Upon reviewing the RHRSW pump IST testing document (OCOS 1000-04), the inspectors discovered that no acceptance criteria existed for the relocated surveillance parameters (i.e.,3500 gpm against a pressure of 198 psig) When the inspectors discussed this with the IST coordinator, he responded that for these pumps, the IST program did not test for operability twt rather degradation Funher, the inspectors learned that the IST coordinator was not aware that, per the SER, the RHRSW IST program was supposed to address operability as a result of the TSUP. In addition, discussions with the TSUP coordinator Indicated that there was not a specific process to ensure surveillance requirements were properly relocated from technical specifications to the IST program as a result of the TSU The inspectors were concerned that operability had not been determined since the prior surveillance requirement completed before transition to the TSUP. The licensee's staff responded by generating a PlF which subsequently included an operability determination which was based on review of earlier test data coupled with hydraulic flow model evaluations. The operability evaluation provided reasonable Lssurance that the system would perform its specified functio The failure to incorporate the requirements and acceptance limits contained in applicable design documents into the IST program is a violation of 10 CFR Part 50, Appendix B, Criterion XI," Test Control"(50 254/97013-01; 50-265/97013-01). The licensee initiated revisions to the RHRSW pump IST procedure to incorporate the acceptance limits,

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Conclualon

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The licensee did not have adequate controls to ensure relocated RHRSW pump

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surveillance requirements were properly implemented in the IST program. The failure to

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incorporate applicable requirements and acceptance limits into the IST program was a l violation of 10 CFR Part 50, Appendix B, Criterion X V. Mannaement Meetinas

! X1 Exit Meeting Summary i

The inspectors presented the inspection results to members of licensee management at the

! conclusion of the inspection on August 6,1997. In addition, a telephone exit was conducted on j

September 5,1997, to notify the licensee of the unresolved items in Sections E1.1 and E1.2.

l The licensee acknowledged the findings presented and did not identify any of the documents t

listed as proprietar l

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PARTIAL LIST OF PERSONS CONTACTED Licensee D. Bailey, Modification Design Engineer

@ 4. Boline, Modification Design Mechanical Group Leader j' b. Kne.op, IST Coordinator 3, Pearce, Plant Manager h C, Peterson, Regulatory Affairs Manager T. Peterson, Regulatory Assurance INSPECTION PROCEDURE USER)

, IP 37700: Design Changes and Modifications

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ITEMS OPENED, CLOSED, AND DISCUSSED

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Oneatd 50-254/97013-01; VIO Failure to incorporate the requirements and acceptanca limits 50-265/97013-01 contained in applicable design documents into the IST program 50 254/97013 02a; URI A dist r2pancy between the RHRSW pump description in the k

S0-265/97013-02a UFSAR and surveillance requirements 50-254/97013-02b; URI Seven out of eight RHRSW pumps do not meet the UFSAR 50-265/97013-02b description

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l LIST OF DOCUMENTS REVIEWED DBD-QC-008, Residual Heat Removal System, Design Basis Document Drawing Number M-37. Rev. AL, Diagram of RHR Service Water Piping Sargent & Lundy Calculation ODC-1000-M-0353, Rev. O, RHRSW Post Modification Tests - '

Assessment No.114 Items

' Sargent & Lundy Calculation PMED-8312-01, Rev. O Sargent & Lundy Specification R 2317 Specification for Miscellaneous Pumps, dated April 13, h 1967 (Revised)

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Unique Test M41-87 002B, RHRSW Pump 1B impeller Replacement and Cut Water Reduction, Rev. O .

Problem Identification Form Number 95-3020, dated December 14,1995 )

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Modification Approval Letter to R. L. Bax, dated March 1,1989 )

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Station Procedure Nos:

OCOS 1000-04 (Rev.12) Quarterly RHR Service Water Pump Operability Test QCOP 1000-30 (Rev. 5) Post-Accident RHR operation

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