ML20141H841

Safety Evaluation Accepting Use of Code Case N-508-1 for All Four Plants for Rotation of Serviced Snubbers & Pressure Relief Valves for Purpose of Testing in Lieu of ASME Code

ML20141H841
Person / Time
Site:	Arkansas Nuclear, River Bend, Waterford
Issue date:	07/30/1997
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20141H837	List: ML20141H833 ML20141H841
References
NUDOCS 9708010220
Download: ML20141H841 (4)

Text

- . ~ , , . . _ _ _ - . . - - . - . . _ . . . _ _ _ _ . _ _ _ _ _ _ _ . . . . _ _ _ _ _ _ _ _ . . _ _ _ _ _ _ _ _ _ _ _ _ _ _ . .

M p T UNITED STATE 8 s

y j

2 NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. seseMo01

\...../

SgETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGUI,All0N 1

RELATED TO REQUESTS FOR RELIEF TO USE ASME CODE CASE N-508-1

{

l ENTERGY OPERATIONS. INC.. ET AL.

l ARKANSAS NUCLEAR ONE. UNITS 1 & 2 l RIVER BEND STATION  ;

! WATERFORD 3 STEAM ELECTRIC STATION l DOCKET NOS. 50-313. 50-368. 50-458. AND 50-382 i'

4 i

I

1.0 INTRODUCTION

{

l l The Code of Federal Regulations,10 CFR 50.55a, requires that inservice  ;

inspt.ction (ISI) of certain ASME Code Class 1, 2, and 3 components be jl performed in accordance with Section XI of the American Society of mechanical  ;

l

}  ; Engineers (ASME) Boiler and Pressure Vassel (B&PV) Code, applicable Edition J

and Addenda, except where specific written relief has been requested by the i licensee and granted by the Commission pursuant to paragraph 10 CFR 50.55a(g)(6)(1), or alternatives approved pursuant to 10 CFR 50.55a(a)(3). In I proposed alternatives, the licensee must demonstrate that

(1) the proposed' .

alternatives provide an acceptable level of quality and safety; or (ii) l compliance would result in hardship or unusual difficulty without. a '

compensating increase in the level of quality and safety.- In requesting relief, the licensee must demonstrate that the requirement is impractical for their facility.

10 CFR 50.55a authorizes the Nuclear Regulatory Commission (NRC) to grant relief from ASME Code requirements upon making the necessary findings for such authorizations. The NRC staff's finding with respect to granting or not granting the relief request as part of the' licensee's ISI program is contained in this Safety Evaluation which addresses the request by Entergy Operations, Inc. (the licensee) for approval to use the ASME Code Case N-508-1 as an alternative to the ASME Code,Section XI requirements for the Arkansas Nuclear One Units 1 and 2, Waterford 3 Steam Electric Station, and River Bend Station (the four plants). The request was forwarded in the licensee's letters dated June 20, 1996, and January 14 and May 12, 1997.

The ISI program for the current interval for the Waterford 3 and River Bend Stations is based on the repair and replacement requirements of Section XI of the ASME Code, 1980 Edition through the Winter 1981 Addenda and the new interval will be based on the 1992 Edition. For Arkansas Units 1 and 2, the current interval is based on the 1986 Edition and the new interval for Unit I will.be based on the 1992 Edition.

ENCLOSURE 9700010220 970730 PDR ADOCK 05000313 P PDR

_ _ . . _ . _ . . ~ _ _ _ . _ . _ . _ _ _ _ _ _ _ _ _ ._ _ . _ _ _

n i ,

i l

i i

2.0 BACKGROUND

ASME Code Section XI Reauirement:

i Article IWA-7000, Replacement, specifies the rules and requirement.s to be used when replacing, among other items, relief. valves and snubbers. In that

article the owner's respor.sibilities are defined and require the owner to i develop a replacement program that meets the requirements of Section IWA-7130, l Replacement Program. When a component is replaced under this program, IAW-7000 requires the preparation of a replacement plan and Form NIS-2, i performance of specific Section XI reviews and evaluations, and review and i

concurrence of the Authorized Nuclear Inspector. These requirements apply even when removing and installing relief valves and snubbers solely for the <

l purpose of testing.

l Code Case N-508-1. " Rotation of Serviced Snubbers and Pressure Relief Valves i for the Purpose of Testina.Section XI. Division 1" Reauirements:

l Code Case N-508-1 provides an alternative to Article IWA-7000 when pressure i relief valves and snubbers are rotated from stock and installed on components i (including piping systems) within the Section XI boundary. Specific L requirements, that are detailed in Code Case N-508-1, must be met when ,

rotating components from stock for the purpose of testing. These requirements l include: the items must be of the same design and construction; the items '

shall have no evidence of failure at the time of removal; items being rotated shall be removed and installed only by mechanical means; items being installed shall previously have been in service; preservice inspections and pressure tests shall be performed as required by IWA-7000; traceability of inservice inspection and testing shall be maintained; the use of an NIS-2 form is not required arcept for repair or replacement of the rotated item; testing of removed snubbers and pressure relief valves, including required sample expansions, shall be in accordance with the owner's test program; and repair or replacement of removed items shall be performed in accordance with IWA-7000.

Staff Review of Code Case N-508-1:

The staff has reviewed Code Case N-508-1 for acceptability and inclusion in Regulatory Guide 1.147, " Inservice Inspection Code Case Acceptability ASME Section XI Division 1." The staff concluded that it would not approve the generic use of the Code Case. The staff's concern was the Code Case did not provide assurance that its application would net adversely impact the existing snubber service life monitoring program. Specifically, when snubbers are rotated between stock and installation, without involving the preparation of a Section XI repair / replacement plan and the subsequent submittal of a Form NIS-2, traceability of the snubbers service life could be compromised. The staff. concluded that it would review the use of the Code Case on a plant-by-plant basis.

E

= , ,

5.  !  :

3.0 RELIEF RE00EST i

l The licensee requests relief from the ASME Code,Section XI, Article IWA-7000 t

replacement requirements for snubbers and pressure relief valves. The j licensee proposed as an alternative to the ASME Code,Section XI requirements,

to use the ASME Code Case N-508-1, titled, " Rotation of Serviced Snubber and

, Pressure Relief Valves for the Purpose of Testing" at Arkansas Units 1 and 2, Waterford 3 and River Bend. The licensee requested approval to use the Code

! Case for snubbers and relief valves that are rotated for testing as an alternative to the requirements of ASME Section XI, Article IWA-7000.

! The licensee stated that currently, when a snubber or relief valve is removed for testing, the activity is required to be treated like an ASME Code,

! l Section XI, Article IWA-7000 replacement activity. This entails the use of i replacement programs, replacement plans, suitable evaluations, ~ unique reviews within the licensee'sSection XI programs, review and concurrence by an Authorized Nuclear Inspector, and maintenance of NIS-2 or other Section XI docuantation to record the replacement. This activity requires the degraded system to remain out of service for the time that the item is removed, tested,  ;

refurbished if necessary, ar.d replaced. The licensee considers these Code (

provisions appropriate when the components are replaced due to design changes, I failures or expiration of component life. However, these activities are l considered excessive for the removal and installation of snubbers and pressure relief valves solely for the purpose of testing. .

The licensee proposed to use Code Case N-508-I when a snubber or pressure relief valve is removed from a system for the purpose of testing, to rotate a i replacement component from spares into its place and to test the removed l component at a later time. The use of the code case allows the licensee to minimize the time that a degraded system remains out of service and reduces i administrative requirements and documentation. The licensee indicated that all the technical requirements for the replacement, test, and repair of l snubbers and pressure relief valves are still maintained in a manner that provides an acceptable level of safety that is consistent with the level of s'afety afforded by compliance with the ASME Section XI requirements that are currently being implemented at each of the licensee's facilities.

If the snubber or relief valve being removed requires a repair or replacement l (i.e., shows evidence of failure) then the replacement of the item will be a typical ASME Code Section XI repair or replacement and not under this Code Case, and the required Section XI documentation will be completed. The use of the Code Case only eliminates unnecessary administrative controls and documentation requirements associated with a replacement of a snubber er relief valve when the item is rotated for testing.

I 4.0 EVALUATION Code Case N-508-1 provides an alternative to the current ASME Code,Section XI, Article IWA-7000 requirement to generate a replacement program when removing snubbers or pressure relief valves from a system for testing. The

__ ~_. _ _ ._. - , . ._

code case allows snubbers and pressure relief valves to be rotated from stock and installed on components and piping systems within the Section XI boundary, provided all the requirements stated in the code case are met.

The code case was approved by ASME on May 11, 1994, however, its use has not been approved by the NRC for any nuclear power plants without the licensees requesting the use of the code case. The staff reviewed the code case and determined that the current text of the code case does not provide assurance that its application will not adversely impact the existing snubber ervice life monitoring program. In response to this concern, the licensee stated that its commitments and programs in effect for monitoring snubber and pressure relief valves service life at the four plants are unaffected by the alternatives of Code- Case N-508-1.

The licensee has agreed to all the Code Case requirements. Further, if the component being removed shows evidence of failure, the licensee will not use Ccde Case N-508-1, but will use ASME Code Section XI, Article IWA-7000 of the ASME B&PV Code for repair or replacement activities.

The licensee's proposed alternative to use Code Case N-508-1, with the provision that the snubber service-life monitoring program is not changed, for the purpose of testing snubbers and pressure relief valves, will eliminate unnecessary administrative and documentation requirements, minimize the time during which the affected system is out of service, and provide an acceptable level of quality and safety in.that adequate assurance of snubber reliability will be maintained.

In considering the licensee's proposed use of Code Case N-508-1, and the responte in addressing the staff's concerns with regard to an adverse impact on the existing snubber sorvice life monitoring program, the staff has determined that the application for the four plants is acceptable.

5.0 CONCLUSION

The staff concludes that the licensees' proposed alternative to use Code Case N-508-1, at the above four plants, for rotation of serviced snubbers and pressure relief valves for the purpose of testing in lieu of ASME Code,Section XI, Article IWA-7000 requirements is authorized by law, pursuant to 10 CFR 50.55a(3)(a)(1). This is based on the staff's determination that the '

use of Code Case N-508-1 at these plants provides an acceptable level of i quality and safety.

Principal Contributor: F. Grubelich Dato: July 30,1997 p -- -p ,omv n-