ML20237G835

Safety Evaluation Re Util 870723 Request for Relief from 4 H Test Pressure Hold Time Requirement of Section XI of ASME Code,1974 Edition Through Summer 1975 Addenda

ML20237G835
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	08/25/1987
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20237G818	List: ML20237G815 ML20237G835
References
TAC-65855, NUDOCS 8709020429
Download: ML20237G835 (3)

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09 *' 4 g UNIT ED STATES g, .S NUCLEAR REGULATORY COMMISSION y e ' ,g W ASHINGTON, D. C. 20555

'" E r, ENCLOSURE SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTO OF A REQUEST OF RELIEF FROM HYDROSTATIC TEST PRESSl HOLD TIME REQUIREMENT OF SECTION XI_ "

PORTLAND GENERAL ELECTRIC COMPANY TROJAN NUCLEAR PLANT DOCKET NO.: 50-344 1

1. Backoround Information 23, 1987, Portland General Electric Company By letter dated July (the licensee) requested relief from the four-hour test pressure hold time requirement of the 1974 Edition through Summer 1975 Addenda of Section XI of the ASME Code following repair of the feedwater lines at In addition to nondestructive (PT, RT, UT)

Trchn Nuclear Plant.

examinations, the repaired feedwater iinestheare requi Infomation supporting .

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visual inspection of the pressure boundary. request was prov this information is evaluated to detemine if request, The the necessary findings can supporting be made to grant the relief as requested.infometion, Code requ '

below.

11. Request, Supportine Information, and Code Requirements A. pelief Requested By Licensee Relief is requested to perform the post-repair hydrostatic test of the main feedwater system piping, maintaining the test pressure for 10 minutes (and for additional time as

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required to check the repaired areas for lealage), vice 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

B. Code Requirement

_Section XI,1974 Edition; Sumer 1975 Addende:

The pressure-retaining components shall be visuelly IWA-5120(a) examined while the system The is under hydrostatic test test pressure and pressure and temperature.

temperature shall be maintained for at least four (4) hours prior to performance of the examinations.

8709020429 870825 PDR ADOCK 05000344 P pyg

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C. Licensee's Basis For Relief Request ..

The licensee stated the following as the basis for the request:

The purpose of the hydrostatic test is to verify the post-repair .l z

structural integrity of the main feedwater system piping.

" IWA-5210 in the 1974 Edition of the Code requires that hydro- l st6 tic test pressure be maintained for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to provide for 1 akage pene-tration through the piping insulation. Later j versions of the code, e.g., the Winter 1975 Addenda, indicate that for exposed piping, the test pres 1;ure need only be '

maintained for 10 minutes, plus additional time as may be required to check for leakage. The repaired sections of main feedwater system piping will be pressure-tested prior to replacing the associated insulation.

Avoiding the 4-hour hold time at test pressure is requested because the longer test duration increases the risk of overpressurizing the steam generators. If the test pressure exceeds 1485 psig, the Technical Specification for steam generator pressure limitation is exceeded. Trojan is allowed only five pressure cycles above 1485 psig over the Plant lifetime 4 Thus compliance with.the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold requirement would increase the level of' hardship and difficulty in performing the test without a compensating increase in the L

level of quality and safety.

j D. Alternative Examination Proposed By Licensee _

The licensee proposed the folic' wing alternative:

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The hydrostatic tett pressure will be maintained for 10 minutes

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A prior to examining the repaired arets for leakage. Test

' pressure will bd maintained above 1406 ibut less psigthan(125the percent 1485 of the psig G' '

system design limitations of thepressure 1125 psig),l Specifications, Table 5.9.1, Trojan Technica '

C mponent or Cyclic Limits.

111. Staf f Evaluatton and Conclusion Thtt staff has reviewed the licensee's request for relief from the

,. four-hour test pressure hold time requirenient!dnd the information l' suppa tim; his request. The purpose of the four-hour hold time is to allow 1eakage from a source sufficient time to penetrate insulation or

• ekepe thi'ough joints and thereby alertLthe inspecter of a throughwall opening in the presr,ure boundary. Por 1noninsulated piping, a four-hour test pressure hold tEne. is not nsessay ber .. Te a source of leakage from the pressure boundary is readily detected. ' fobr-hour hold time Edition was changed to requirement for nonimsulated syttas in ti- 9 ecognition of this fect.

}sA ten minutes in later editions of Section )

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,1 s Based upon the above, the staff finds that the requirement, if imposed upon the licensee, would not increase thc quality or level of safety of the plant or enhance the effectiveness of the hydrostatic test of the o repaired feedwater piping. The alternative test proposed by the licensee in conjunction with the other nondestructive examinations performed on the repaired feedwater piping will provide assurance of its structural integrity.

We therefore, conclude that relief from the four-hour hold time requirement may be granted as requested.

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