ML20212Q616

Forwards Thermal Stress Fatigue Analysis of Big Rock Point Emergency Condenser Outlet Nozzle, as Part of Integrated Plan Issue BN-090 Re Classification of Structures,Sys & Components (SEP Topic III-1)

ML20212Q616
Person / Time
Site:	Big Rock Point File:Consumers Energy icon.png
Issue date:	08/29/1986
From:	Frisch R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	Office of Nuclear Reactor Regulation
Shared Package
ML20212Q619	List: ML20212Q616 ML20212Q626
References
TASK-03-01, TASK-3-1, TASK-RR NUDOCS 8609050316
Download: ML20212Q616 (2)

Text

Consumers Povver rewaums MEMGAW5 MtOGetEKE General offices: 1945 West Parnall Road Jackson, MI 49201 . (517) 788-0550 August 29, 1986 Director, Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLANT -

INTEGRATED PLAN ISSUE BN-090 - CLASSIFICATION OF STRUCTURES, SYSTEMS AND COMPONENTS - SEP TOPIC III-1 As part of the Big Rock Point Integrated Assessment, Section 4.4.1, the NRC staff requested that Consumers Power Company demonstrate that the impact of cyclic loading on selected piping and vessel elements comply with the requirements of the ASME Code.

The impact of cyclic loading on piping analysis was submitted to the NRC in our February 10, 1986 letter. This letter transmits the cyclic loading analysis for vessel elements.

The component selected for the pressure vessel element of the SEP Topic III-1, Classification of Structures, Systems and Components (Seismic and Quality),

was the Emergency Condenser Outlet Nozzle. This nozzle, made of dissimilar metals without a thermal shock liner, undergoes a relatively severe transient during a reactor scram if the emergency condenser is put into service. The nozzle experiences a sudden transient from 126* to about 592*F, then a slow decay approaching 210*F in about three hours.

A finite element thermal stress analysis and a fatigue usage calculation in accordance with NB3222.4 of the ASME Code, Reference (2), was conducted. The results indicate that the components design, conservatively, have a life of 427 cycles. Three candidate nozzles, emergency condenser outlet, emergency condenser condensate return to steam drum and steam drum feedwater, were considered for the analysis. The emergency condenser outlet nozzle was ultimately annlyzed based on severity of thermal strees as detailed in Reference (3). Based on historical data, the expected total usage of the emergency condenser outlet and condensate return nozzles will be less than 150 cycles and steam drum feedwater nozzle will be less than 300 cycles.

Therefore, the fatigue usage factor for all nozzles is less than 1.0.

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Director, Nuclear Reactor Regulation 2 Big Rock Point Plant Integrated Plan Issue BN-090 August 29, 1986 The attached Thermal Stress Fatigue Analysis of Big Rock Point Emergency Condenser Outlet Nozzle by NTS, Reference (3), is a final report and completes our actions associated with this SEP Topic and Integrated Plan Issue.

DA Ralpi R Frisch Senior Licensing Analyst CC Administrator, Region III, USNRC NRC Resident Inspector - Big Rock Point Plant Attachment References

1. Letter from D M Crutchfield (NRC) to D J VandeWalle (CPCo), "SEP Topic III-1, Quality Group Classification of Components and Systems (Big Rock Point), April 16, 1982.

2. ASME Boiler and Pressure Vessel Code,Section III, Division 1, Subsection NB and Appendices, 1983.

3. Thermal Stress Fatigue Analysis of Big Rock Point Emergency Condenser Outlet Nozzle, National Technical Systems, Long Beach, California.

Technical Report #86-1548, August 1986.

OC0886-0139-NLO4