IR 05000255/1994002

Provides Assessment of Unresolved Items from Svc Water Sys Operational Performance Insp Rept 50-255/94-02 on 940110- 0211

ML18059B180
Person / Time
Site:	Palisades
Issue date:	09/02/1994
From:	Rogers D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9409130354
Download: ML18059B180 (5)

Text

... . consumers Power POWERINli lllllCHlliAN'S PROliRESS Palisades Nuclear Plant: 27780 Blue Star Memorial Highway, Covert, Ml 49043 September 2, 1994 Nuclear Regulatory Commissio Document Control Desk Washington, DC 20555 David W. Rogers Plant Safety and Licensing Director DOCKET 50-255 -LICENSE DPR-20 -PALISADES PLANT -ASSESSMENT OF UNRESOLVED ITEMS FROM THE SWSOPI INSPECTION (NRC INSPECTION REPORT NO. 50-255/94002(DRS))

A Service Water System Operational Performance Inspection (SWSOPI) was conducted at the Palisades plant over the period from January 10 through February 11, 1994. NRC Inspection Report No. 50-255/94002(DRS), dated March 4, 1994, provided the results of the SWSOPI inspection and discussed a number of unresolved items and weaknesse Consumers Power Company letter, dated April 8, 1994, provided the individual responses to each of the unresolved items and weaknesse The NRC's May 12, 1994 letter acknowledged that the corrective actions and schedule for addressing the unresolved items and weaknesses appeared appropriat This letter also requested that we provide the NRC with the unresolved items assessments when they are complet This letter provides our assessment of the unresolved items as requested by NRC letter, dated May 12, 1994. The referenced analysis, tests, and inspection results are available at Palisades for NRC review. Unresolved Item 92028-03 Use of firewater to provide backup water supply for auxiliary feedwater (AFW). The NRC's concern was based on the lack of an analysis or testing to verify the fire water system's capability to provide backup water to the AFW system. The licensee committed to complete an analysis to document the fire water system adequacy under action item request (AIR) A-PAL-92-09 l..., 0 ( l *"\ ..Ji..Jl. !C . PDR ADOCK 05000255 . A OJ5 ENER<SY COMPANY <¢°\ '<0 0 PDR2:t

.* Resolution An analysis of the fire water system's capability to provide backup water to the auxiliary feedwater system has been complete The analysis (EA-A-PAL-94-095)

concludes that the emergency backup supplies from service water and fire water provide a net positive suction head that is greater than the required net positive suction head for the normal auxiliary feedwater pump suction. In addition, a special test (T-345) was performed to verify that the fire system supply is capable of providing the required water to the auxiliary feedwater system. The test results clearly showed that the fire water line to the auxiliary feedwater system is free and clear and capable of providing much more flow than require Unresolved Item 94002-01 2 The team identified the lack of over-pressure protection for CCW heat exchangers (HX) E-54A and E-548. The concern involved over-pressure due to thermal expansion stemming from service water valve isolatio Palisades'

ASHE Code of record required each vessel to be protected from any conditions specified in the certified design specificatio The code further required to document the degree of over-pressure protection in a summary technical report. The licensee was unable to retrieve the summary technical report that justified the lack of over-pressure protection prior to completion of the inspectio The licensee committed to locate the report or perform the technical analysis to show Code complianc Resolution A search conducted by the original plant architectural engineer did not find a "sununary technical report" for the component cooling water heat exchanger Therefore, an analysis (EA-A-NL-94-078-01)

was performed to verify that the critical portion of the service water system, including the component cooling water heat exchanger, is adequately protected against over pressur The.conclusion .of the analysis is that the. critical.portion**ofthe service water system is adequately protected against over pressure arising from steady state or transient conditions of pressure and temperatur Unresolved Item 94002-02 -The results of tests, calculations and engineering evaluations were inconclusive and could not be used to determine if the SWS would fulfill its safety related function at elevated lake water temperatures combined with other adverse design basis condition ... * 3 The licensee concluded that the SW and CCW systems were currently operable becau*se *current lake water temperatures were less than 50"F. This temperature provided significant margin to account for all issues impacting the SW operability margin. The licensee corrunitted to resolve the fo11owing issues, documented in DR D-PAL-93-272, by mid April 1994. A. Neither test results or design basis calculations accounted for instrument uncertaintie . The analyses that develop required flow rates to HXs served by the SWS used only the original design fouling. No calculations had been performed to evaluate degraded HX performance resulting from fouling beyond the original design value. C. The most limiting system lineup may not have been tested. D. The impact of increased SW temperatures and reduced SW flow rates on the SW and CCW design pressures and temperatures and systems' operation was no.t eva 1 uated. E. The root cause of declining flow rates to control room chillers VX-10 and VX-11 had not been determine * F. As discussed in Section 8.1, the SW pump IST reference values and pump degradation was not coupled to the required system performanc G. The elevated lake water temperature was not incorporated into the maximum allowable SW system degradatio Pending the licensee's completion of all the actions impacting SWS margin documented in DR D-PAL-93-272 and review by the NRC, this is considered an unresolved item (50-255/94002-02).

• Resolution Appropriate testing and engineering analysis have been performed, as described below, to show that the service water system would fulfill its safety related function under postulated worst single active failures and elevated lake water temperature A. Engineering analyses of system flows were performed for the service water and component cooling systems taking into account appropriate uncertainties associated with system testing (reference PAL-93-272E.)

B. An analysis (EA-D-PAL-93-2720-01)

of appropriate heat exchanger fouling factors to be used in heat exchanger performance analysis for the service water system was complete The analysis was based on the Tubular Heat Manufacturer's Association (TEMA) standards and considered the serv1ce conditi-0ns of the heat exchanger * C. The analysis of system flows (item A above) included verification of the most severe system lineups and single failure D. The maximum expected service water and component cooling system temperatures have been evaluated and found acceptable and in accordance with the design of the system piping and components (reference D-PAL-93-272C and G.) 4 E. The primary root cause of the declining service water flows to the control room chillers VC-10 and VC-11 has been determined and correcte An inspection of the heat exchanger head gaskets found them to be excessively large and blocking a significant number of flow tubes (reference C-PAL-94-0188.)

F. The engineering analyses of system flows (item A) took into account appropriate allowances for pump degradatio Section.XI pump test reference values were established based on thest-analyses, and test procedures and associated basis documents have been revised to reflect the new reference values. Pump performance was compared to the new reference values and no operability concerns were identified (reference D-PAL-93-272A.)

G. Engineering analyses have been performed to demonstrate that service water flows are adequate to cool critical plant systems and equipment under all postulated single active failures and assuming a lake water temperature of 85°F. The plant areas and equipment evaluated include the containment building, the control room, the engineered safeguards rooms, and the diesel generators (reference D-PAL-93-272E.)

Unresolved Item 94002-03 Corrective actions in response to D-PAL-93-272 wi11 complete the development of SWS pump testing reference values and required system performanc Additiona11y, the 1icensee .intended to r.ev.ie the basis .for IST referenc values and allowed degradation for a11 Section XI pump tests to ensure that they were adequately coordinated with safety analysis performance criteri This issue is considered an unresolved item pending the licensee's review to determine impact on the IST reference values and the possible effect on past ESS pump operabilit Resolution Engineering analyses of system flows taking into account appropriate allowances for pump degradation have been completed for all safety-related pumps.Section XI pump test reference values were established based on these analyses, and test procedures and associated basis documents have been revised to reflect the new reference values. Pump performance was compared to the new reference values and no operability concerns were identified (reference D-PAL-93-272A.)

• j 5 Commitment Summarv This letter provides the results of our previously*conunitted actions and makes no new conunitment David W Rogers Safety and Licensing Director CC: Administrator, Region Ill, USNRC Resident Inspector, Palisades