ML20050C206

Application for Amend to License DPR-51 Extending Exemption from 10CFR50,App H to Allow Irradiation of Surveillance Specimens Outside Facility.Basis for Extension Encl

ML20050C206
Person / Time
Site:	Arkansas Nuclear
Issue date:	04/02/1982
From:	Cavanaugh W ARKANSAS POWER & LIGHT CO.
To:	Stolz J Office of Nuclear Reactor Regulation
References
1CAN048204, 1CAN48204, NUDOCS 8204080278
Download: ML20050C206 (11)

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ARKANSAS POWER & LIGHT COMPANY FIRST NATIONAL BUILDING /P.O. 80x 551/UTTLE ROCK. ARKANSAS 72203/I501) 371-4422 April 2, 1982 WILLIAM CAVANAUGH, lil Senior Vice President Energy Supply @ A e 'b p GCCE!'MD 9 APR 7 1982c,.

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Director of Nuclear Reactor Regulation 16 ATTN: Mr. J. F. Stolz, Chief Operating Reactors Branch #4 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C. 20555

Subject:

Arkansas Nuclear One - Unit 1 Docket No. 50-313 License No. DPR-51 Reactor Vessel Surveillance-Appendix H Exemption Request

[Fi1e: 1511.1)

Gentlemen:

Your letter dated April 1,1977, granted an exemption to 10 CFR 50 Appendix H for ANO-1 to allow irradiation of surveillance specimens at Davis-Besse Unit No. 1 for five years. AP&L has been following a proposed revision to Appendix H that would allow AP&L to perform this irradiation outside the ANO-1 vessel without seeking an exemption to Appendix H. However, since this revision is still pending we must request an extension to the exemption given on April 1, 1977. We request that this extension be granted until the proposed Appendix H revision becomes official at which time the exemption will no longer be needed.

Presently, ANO-1 is shut down for a maintenance outage and must receive the extension for exemption to Appendix H before we can restart the unit.

Based on our present schedule we plan to restart ANO-1 on April 27, 1982.

We request your expeditious review of this matter to avoid delay in the restart efforts. Attached is a report which summarizes the results of the ANO-1 reactor vessel surveillance program over the past five years and provides the basis for the exemption request.

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MEMOEH MICOLE SOUTH UTILITIES SYSTEM S

, , Mr. J. F. Stolz April 2, 1982 Pursuant to the requirement of 10 CFR 170.22, we have determined this request to involve a Class III fee for a single safety issue amendment ~to s our license. Accordingly, a check in the amount of $4,000.00 is /

remitted.

'Very truly yours,j' William Ca augh III i

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STATE OF ARKANSAS )

) SS COUNTY OF i.LASKi j I, William Cavanaugh III, being duly sworn, subscribe to and say that I am Senior Vice President, Energy Supply for Arkansas Power & Light Company; that I have full authority to execute this oath; that I have read the document numbered ICAN048204 and know the contents thereof; and that to the best of my knowledge, information and belief the statements in it are true.

.2 William Ca gh III SUBSCRIBED AND SWORN T0 before me, a Notary Public in and for the CountyandStateabovenamed,this[ day of ,

1982.

Q OL Gl/L M Notary Public

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My Commission Expires:

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BASIS FOR EXTENSION OF EXEMPTION FROM PROVISIONS OF 10 CFR 50 APPENDIX H INTRODUCTION In early 1977, Arkansas Power & Light Company (AP&L) requested by Reference 1 an exemption from the requirements of 10 CFR 50 Appendix H.

This exemption was granted by Reference 2 and allowed continued operation of the Arkansas Nuclear One-Unit 1 (ANO-1) while irradiating reactor vessel surveillance capsules at Toledo Edison Company's Davis Besse Unit 1.

This exemption was granted for a period of five years with a provision for extending the exemption based on successful operating experience.

This report is a summary of the experience AP&L has had with the Integrated Reactor Vessel Surveillance Program (IRVSP) and the future plans for the prcgram. An adequate justification for the extension of the exemption from the requirements of Appendix H-to 10 CFR 50 is provided.

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DISCUSSION Operating Experience Surveillance Specimen Holder Tubes The key factor leading to AP&L participation in the IRVSP and Reactor Vessel Material Owners Group was the loss of integrity of the Surveillance Specimen Holder Tubes (SSHT's) and their subsequent removal from AN0-1. It was concluded that, although the installation of re-designed SSHT's was feasible on an operating plant, the benefits did not justify the costs associated with the development of remote tooling, extended plant downtime, and significant radiation exposure to personnel.

The Owners of the affected operating plants entered into agreements with Utilities that were scheduled to bring new plants on line in the near future, to continue the Reactor Vessel Surveillance capsule irradiation at these new " host" plants. The ANO-1 reactor vessel materials surveillance capsules were installed in SSHT's at Davis Besse 1. The SSHT's at Davis Besse 1, including the supports and bolts that attach them to the Thermal Shield, have been examined via remote video inspection during refueling outages. No loss of structural integrity has 2

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. - l been observed. In addition, there have been no signals provided by the loose parts monitoring system which would indicate the loss of integrity of the SSHT's or their mounting at 08-1. There are no plans to modify the SSHT's or the Core Support Assembly on any operating B&W plant which would change the geometric similarity of the reactors or preclude the 4 continued irradiation of surveillance capsules in the host plants. Thus, adequate surveillance information will continue to be obtained for AN0-1.

Surveillance Capsules Evaluated B&W has evaluated 12 surveillance capsules that have been removed from operating B&W plants, they are:

Plant Name Capsule I.D. Report Number /Date Oconee 1 OCI-F BAW-1421, August 1975 Oconee l' OCI-E BAW-1436, September 1977 Oconee 2 0CII-C BAW-1437, May 1977 Oconee 2 0CII-A BAW-1699, November 1981 Oconee 3 0CIII-B BAW-1697, October 1981 Oconee 3 0CIII-A BAW-1438, July 1977 Three Mile Island 1 TMI-1E BAW-1439, January 1977 Arkansas Nuclear One-1 ANI-E BAW-1440, April 1977 Arkansas Nuclear One-1 ANI-B BAW-1698, November 1981 Crystal River 3' CR3-B BAW-1679, June 1981 Rancho Seco RSI-B BAW-1702, January 1982 Davis Besse TEI-F BAW-1701, January 1982 3

The surveillance capsules other than those owned by AP&L are significant because of participation in the B&W IRVSP by many utilities. The information shared among Utilities with rea'ctors constructed of similar materials, supplemented with future capsule evaluations testing of special research capsules, and data obtained from NRC sponsored test reactor programs, will provide a data base which permits a continuing evaluation of the behavior of these materials in a reactor. vessel environment. Based on the surveillance capsule data obtained from all the B&W-177 FA plants to date, it has been demonstrated that the prediction techniques used in the establishment of vessel operation limitations (i.e., Reg. Guide 1.99, Rev. 1) are conservative.

The Crystal River, Rancho Seco and Davis Besse capsules contain weld metal compact fracture specimens that will be tested using a single 4 specimen J-Integral technique in early 1982.

Reactor Vessel Fluence Evaluation A concern which developed as a result of the removal of the SSHT's was the inability to monitor the fluence received by the reactor vessel wall.

However, due to the geometric similarity of plants, the fluence accumulated by the reactor vessels in plants without SSHT's can be 4

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calculated based on their power histories and dosimetry measurements from plants with SSHT's. Continued refinement of these analytical techniques is being accomplished through B&W participation in the NRC sponsored " LWR Pressure Vessel Irradiation-Surveillance Dosimetry Program". A high degree of analytical accuracy by B&W has been demonstrated .in the NRC program to date, and continued participation is expected to improve the fluence evaluation capability.

Capsule Fluence vs. Reactor Vessel Fluence Because of the relatively large lead factors [ fast flux (E > 1 MEV) at capsule centerline divided by the fast flux at 1/4 thickness of reactor vessel] associated with the location of the SSHT's at the Host Reactors, the similarity of plant capacity factors, and the similarity of fuel management at both Davis Besse 1 and AN0-1; the neutron fluence received by the Arkansas surveillance capsules being irradiated in Davis Besse 1 leads the neutron fluence experienced by the Arkansas vessel.

Calculations show that the Arkansas reactor vessel has achieved an accumulated neutron fluence at the 1/4t location (as of December 31, 1981) calculated at:

Plant nicm2 (E > 1 MEV) Equivalent EFPY ANO-1 1.2 x 10 18 4.5 5

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The Arkansas surveillance capsule r.ost recently removed from Davis Besse 1 achieved a neutron fluence from irradiation at both Arkansas and Davis  ;

Besse 1 of:

Capsule n/cm2 (E > 1 MEV) Equivalent EFPY ANI-BA 4.3 x 10 18 17 The capacity factor of Davis Besse 1 since November 11, 1977, its commercial operation date, through December 31, 1981 is 0.40 cnd for comparison, the capacity factor of ANO-1 is 0.63.

With lead factors in the range of 7 to 10, the surveillance capsules are expected to continue to lead the respective reactor vessel's accumulated peak fluence.

Additionally, specimens made of related weld metals were donated to NRC 1

. sponsored research programs and have been irradiated in test reactors to f fluence levels beyond that expected to be achieved by the Arkansas-

' reactor vessel at the end of service live. Data from these test reactor programs are becoming available and will be evaluated for' applicability to the Arkansas reactor vessel.

i Future Plans Of particular interest to ANO-1 is that, in addition to plant' specific capsules scheduled for withdrawal over the next.several. years, two research capsules which are a part of the IRVMSP are to be withdrawn from 6

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e operating reactors in 1983. These capsules contain Charpy V-notch and compact fracture specimens made from weld metalt inich have a direct relationship to weld metal in ANO-1 reactor vessel as follows:

Capsule Reactor No. Estimated Capsule Fluence Equivalent EFPY <

CR3-LI CR3 6.6 x 10 18 31 DB-LI DB-1 5.4 x 10 18 25 The testing of these research capsules, which are supplemental to the plant specific capsules, will yield valuable power reactor irradiation information on materials similar to those actually found in the reactor vessel.

CONCLUSION The objective and technical description of the IRVSP has not changed from that described in the Safety Evaluation by the Office of Nuclear Reactor Regulation supporting Amendment No. 22 Facility license DPR-51. The IRVSP continues to provide material data that leads the reactor vessel and has demonstrated that the material behavior prediction techniques are conservative. No operational or fuel management modifications that will adversely affect the IRVSP are expected.

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• Based on the successful experience of the IRVSP to date, it is requested that AP&L be' granted a continued extension of their exemption from the provisions of Appendix H to 10 CFR 50, by continuing the irradiation of the remaining Arkansas surveillance specimens at Toledo Edison Company Davis Besse 1.

Reference 1 - Letter dated August 17, 1976, to Mr. Dennis L. Ziemann from Mr. J. D. Phillips (AP&L letter no. ICAN087619).

Reference 2 - Letter dated April 1, 1977, to Mr. J. D. Phillips from Mr. Victor Stello, Jr.

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