1CAN069604, Forwards ASME Relief Request Re Hold Times for Class 1 Sys Hydrostatic Exams

Forwards ASME Relief Request Re Hold Times for Class 1 Sys Hydrostatic Exams

ML20117M155
Person / Time
Site:	Arkansas Nuclear
Issue date:	06/12/1996
From:	Mims D ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
1CAN069604, 1CAN69604, NUDOCS 9606180149
Download: ML20117M155 (7)

Text

Entergy Operations,Iric.

-r- - ENTERGY C"ff,

. .e mi m wo June 12,1996 1CAN069604 U. S. Nuclear Regulatory Commission Document Control Desk Mail Station PI-137 Washington, DC 20555

Subject:

Arkansas Nuclear One - Unit 1 Docket No. 50-313 License No. DPR-51 Request for ASME Relief on Hold Times for Class 1 System Hydrostatic Examinations Gentlemen:

Title 10 of the Code of Federal Regulations, Part 50.55a, requires that inservice inspection of certain ASME Code Class 1,2, and 3 piping be performed in accordance with Section XI of the ASME Boiler and Pressure Vessel Code and applicable addenda, except where alternatives are authorized or relief is granted by the Commission pursuant to 10 CFR 50.55a(a)(3)(i), or (a)(3)(ii). In order to obtain authorization or relief, the licensee must demonstrate under (i) that the proposed alternatives provide an acceptable level of quality and safety, or under (ii) compliance would result in hardship or unusual difliculty without a compensating increase in the level of quality and safety. In accordance with the above criteria, attached is a request for relief to the NRC approved ASME Code Case N-498-1 for Arkansas Nuclear One, Unit 1 (ANO-1). This relief would authorize the use of an alternative application of a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> " soak time" for Class I systems instead of the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time required by Code Case 498-1.

Entergy Operations received NRC staff approval to use Code Case N-498-1 in letter dated Febmary 27,1995 (0CNA029520). This relief provided a significant reduction in the burden associated with performance of 10-year hydrostatic tests. Code Case N-498-1 was written to lower the test pressure to nominal operating pressure from that required by the hydrostatic test. In the NRC's safety evaluation for approval of Code Case 498-1, the NRC staff noted that hydrostatic testing is primarily regarded as a means to enhance leakage detection during the examination of components under pressure because such testing provides a good g indication of any system leakage, especially those very small leaks that might originate from i small through-wall cracks of the pressure boundary. The capability to detect a very small leak

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. U. S. NRC l June 12,1996 i

' l PAGE2 is a function of both test pressures and hold times. The hold times required by hydrostatic test l were specifically retair.ed in the Code Case N-498-1.

On December 28, 1995, Entergy Operations submitted a request for relief pursuant to 10CFR50.55(a)(3) for use ASME Code Case N-498-2 as an alternative to the ASME Section XI Code requ'irements. Code Case N-498-2, " Alternative Requirements for 10-year System IIydrostatic Testing for Class 1, 2 and 3 Systems, Section XI, Division 1" eliminates the l recent requirement adopted in the 1992 Section XI portion of the Code to require a hold time of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for insulated systems and 10 minutes for uninsulated systems. On April 19,1996, the NRC denied Entergy Operations' request for generic relief of Code Case N-498-2 based, t in part, on the concern that eliminating all hold times may not allow adequate

pressure / temperature conditions which would detect small through-wall flaws. Based on i further discussions with the NRC Staff, it was understood that the primary concern with approval of Code Case 498-2 was that there may not be any time for certain systems (Class 2 l- and 3 systems) to experience increased pressure / temperature conditions (soak time) whereby j leakage would be evident.

In the NRC's April 19,1996 letter, the NRC stated that although the staff finds the generic implementation of Code Case N-498-2 on a plant wide basis to be unacceptable, the staff

would review on a system-by-system basis special situations or alternatives similar to Code Case N-498-2 including the use of shorter hold times in accordance with provisions of 10 i I

CFR 50.55a(a)(3).

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Therefore, Entergy Operations requests NRC relief for ANO-1 to ASME Code Case N-498-1 j for ASME Class I systems within the RCS boundary that is pressurized during reactor pressurization. For ANO-1, the continued requirement of a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time would add i approximately 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to the unit outage time for the hydrostatic examination. This would equate to approximately $88,000 of additional outage critical path time from startup from the next ANO-1 refueling outage beginning in mid -September 1996. The attached alternative is believed by Entergy to meet relief criteria of 10CFR 50.55a(a)(3).

l l Your review and approval of the attached proposed reliefis requested by September 6,1996 j in order to support the next ANO-1 refueling outage. Please contact our Mr. Steve Bennett of my office at (501) 858-4626, ifyou have any questions.

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. U S.NRC.

June 12,1996 - l PAGE3 Very truly yours,-

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Dw'gh .Mims Din or, Nuclear Safety DCM/sab ~

Attachment 1

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. U S. NRC o June 12,1996 PAGE4.

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, cc: Mr. Leonard J. Callan Regional Administrator U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 l Arlington, TX 76011-8064 NRC Senior Resident Inspector l Arkansas Nuclear One

P.O. Box 310 London, AR 72847 Mr. George Kalman

NRR Project Manager Region IV/ANO-1 & 2 1 U. S. Nuclear Regulatory Commission

'NRR Mail Stop 13-H-3 One White Flint North 11555 Rockville Pike Rockville, MD 20852 a

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. Attachment to

. ICAN069604 Page l of 3 Relief Request 96-002 Request for Relief on Insulated System Hold Time For 10 Year Hydrostatie Examinations Apolicable Interval:

Current (Second) Interval Apolicable Edition and Addenda of ASME Section XI:

1980 Edition with Addenda through Winter 1981 Code Class:

Code Class 1 Component:

Applicable to ASME Class I pressure boundaries on Reactor Coolant System (RCS) that are pressurized during reactor pressurization.

Category:

ASME Section XI, Table IWB-2500-1, Examination Category B-P, and Table IWC-2500-1 Examination Category C-H.

Description:

Hydrostatic testing of ASME Class 1 pressure retaining boundaries within the RCS that are pressurized during reactor pressurization.

Reauirement from which Reliefis Reauested:

4 Code Case N-498-1 as previously approved for ANO-1 allows the RCS hydrostatic test be performed each 10-year inspection interval under nominal RCS pressure on pressure retaining components but requires that a four (4) hour hold time be required after the RCS reaches normal operating pressure.

Specific Relief Reauested:

Permission is requested to perform ASME Section XI Pressure Testing of Class I systems within the RCS boundary that are pressurized during reactor pressurization per the requirements of N-498-1 with no holding time after attaining

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. Attachment to i

- ICAN069604 Page 2 of 3

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test pressure if the system has already received a minimum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> ofincreased l I

l pressure during RCS heatup.

Basis for Relief

I l Pursuant 10 CFR 50.55a(a)(3)(i), reliefis requested on the basis that the proposed t

alternative provides and acceptable level of quality and safety and pursuant to 10

CFR 50.55a(a)(3)(ii) compliance with the specified requirements would result in a

hardship without a compensating increase in quality and safety.

I The normal system leakage test evolution for Class 1 systems involves taking the RCS gradually up in pressure and temperature in accordance with the technical specification pressure / temperature limitations. This gradual pressure increase

- during heatup where the pressure has not reached normal operating pressure, but is

providing a driving force for leakage detection is, for the purposes of this

! submittal, considered " soak time". Soak time for the RCS is inherent to the method of testing for reaching the required test pressure for examination. Instead of holding the RCS for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> after reaching system operating pressure, ANO-1

, proposes to utilize the system heatup time as an acceptable alternative to the 4

hour hold time. This alternative will require a minimum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> heatup time j with the RCS under pressure and the examination to not be perfomied until the ,

j RCS has reached normal operating pressure. As a result, potential flaws would ,

, experience pressure conditions approaching normal operation, thus satisfying the

, intent of the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time for insulated systems. Therefore, the additional hold times for Class 1 insulated systems currently required by ASME XI and Code Case 4

N-498-1 would not provide any additional safety benefit.

Leakage identified during previous performance of periodic tests and 10 year tests have not identified any through wallleakage at ANO-1. The only leakage identified during the performance of these pressure testing activities has been from i mechanicaljoints or valve packing.

i Reliefis being requested on the application of additional hold times prior to VT-2 testing for the subject pressure boundaries currently required by ASME Section XI and Code Case N-498-1. Maintaining this hold time would result in an increased hardship to ANO-1 with no appreciable increase in quality or safety for Class I systems. On ANO-1 the additional 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time is critical path during startup from the outage. This isjustified based on the RCS Systems having already been pressurized for at least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> which would provide sufficient time for any evidence ofleakage to occur oninsulated systems.

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. Attachment to

- 1CAN069604 Page 3 of 3 s Alternative Examination:

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' J Instead of holding the RCS for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> after reaching system operating pressure, i ANO-1 proposes to utilize the system heatup time as an acceptable alternative to the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> hold time. This alternative will require a minimum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> heatup time with the RCS under pressure and the examination to not be performed until the RCS has reached normal operating pressure.

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