ML20133M292
| ML20133M292 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 01/15/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20133M278 | List: |
| References | |
| NUDOCS 9701220331 | |
| Download: ML20133M292 (7) | |
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.. pmag y k UNITED STATES g ,j'* NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 306e6-0001 l
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION l l
OF THE THIRD TEN YEAR INTERVAL INSERVICE INSPECTION PROGRAM PLAN RE0 VEST TO USE CODE CASE N-535 1
IES UTILITIES INC. )
CENTRAL IOWA POWER COOPERATIVE CORN BELT POWER COOPERATIVE DUANE ARN0LD ENERGY CENTER DOCKET N0. 50-331 l
1.0 INTRODUCTION
l The Technical Specifications for Duane Arnold Energy Center state that the inservice inspection of the American Society of Mechanical Engineers (ASME) l Code Class 1, 2 and 3 components shall be performed in accordance with
! Section XI of the ASME Boiler and Pressure Vessel Code and applicable addenda as required by 10 CFR 50.55a(g), except where specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i). Section 50.55a(a)(3) states that alternatives to the requirements of paragraph (g) may be used, when authorized by the NRC, if (i) the proposed alternatives would provide an acceptable level of quality and safety or (ii) compliance with the l specified requirements would result in hardship or unusual difficulties without a compensating increase in the level of quality and safety.
Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1, 2 and 3 components (including supports) shall meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in the ASME Code,Section XI, " Rules for Inservice Inspection of Nuclear Power Plant Components," to the extent practical within the limitations of design, geometry and materials of construction of the components. The regulations require that inservice examination of components and system pressure tests conducted during the first 10-year interval and subsequent intervals comply with the requirements in the latest edition and addenda of Section XI of the ASME Code incorporated by reference in 10 CFR 50.55a(b) 12 months prior to the l start c ~ the 120-month interval, subject to the limitations and modifications listed therein. The applicable edition of Section XI of the ASME Code for the Duane Arnold Energy Center third 10-year inservice inspection (ISI) interval is the 1989 Edition. The components (including supports) may meet the l requirements set forth in subsequent editions and addenda of the ASME Code incorporated by reference in 10 CFR 50.55a(b) subject to the limitations and modifications listed therein and subject to Commission approval.
ENCLOSURE 1
! 9701220331 970115 l PDR ADOCK 05000331 l
G PDR I
Pursuant to 10 CFR 50.55a(g)(5), if the licensee determines that conformance with an examination requirement of Section XI of the ASME Code is not practical for its facility, information shall be submitted to the Commission in support of that determination and a request made for relief from the ASME Code requirement.
After evaluation of the determination, pursuant to 10 CFR 50.55a(g)(6)(i), the Commission may grant relief and may impose alternative requirements that are determined to be authorized by law, will not endanger life, property, or the common defense and security, and are otherwise in the public interest, giving due consideration to the burden upon the licensee that could result if the requirements were imposed. In a letter dated April 26, 1996, IES Utilities submitted to the NRC its third 10-year interval inservice inspection program ;
and associated requests for relief. On July 30, 1996, the staff sent a i request for additional information (RAI) to the licensee. By letter dated September 30, 1996, the licensee responded to the RAI and revised or added Requests for Relief Nos. NDE-R022, NDE-R024, NDE-R025, and NDE-R026. After discussions with the staff on October 21, 1996, and October 24, 1996, the licensee submitted a letter dated October 31, 1996, which withdrew these relief requests and requested authorization to use the alternatives described in American Society of Mechanical Engineers (ASME)Section XI Code Case N-535,
" Alternative Requirements for Inservice Inspection Intervals." The 1icensee had requested that the staff review Requests for Relief Nos. NDE-R022, NDE-R024, NDE-R025, and NDE-R026 separately because they were required for an October 1996 outage.
2.0 EVALVATION The staff, with technicel assistance from its contractor, the Idaho National Engineering Laboratory (INEL), has evaluated the information provided by the licensee in support of its third 10-year interval inservice inspection program pian request to use Code Case N-535 " Alternative Requirements for Inservice }
Inspection Intervals" as an alternative to the Code requirements for the Duane i Arnold Energy Center. '
Code Case N-535 allows licensees to examine components in accordance with the ISI program examination schedule for the subsequent interval when an outage associated with the completion of a current interval is within 1 year of the subsequent interval. This Code Case does not allow examinations performed to complete a current interval examination program to be credited to both the ending interval and new interval. In addition, the percentage of examinations required to be completed each period must be satisfied. Therefore, l
verification of the structural integrity of components will be performed with an acceptable frequency, providing an acceptable level of quality and safety.
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i CONCLUSIONS Based on the information submitted, the staff has adopted the contractor's conclusions and recommendations presented in the enclosed Technical Letter Report. The staff has reviewed the information provided by the licensee in support of the proposed use of Code Case N-535, Alternative Requirements for Inservice Inspection Intervals. Based on this review, the staff concludes that the licensee's proposal to implement alternatives contained in Code Case N-535 will provide an acceptable level of quality and safety by maintaining essentially the same frequency between examinations, varying by no more than
- one year, and the percentage of components examined each period as required by Code. Therefore, the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(i).
Use of Code Case N-535 is authorized for the current interval or until such time as the Code Case is published in a future revision of Regulatory Guide 1.147. At that time, if the licensee intends to continue to implement this Code Case, the licensee is to follow all provisions in Code Case N-535 with limitations issued in Regulatory Guide 1.147, if any.
Principal Contributors: Tom McLellan Glenn Kelly Dated: January 15, 1997 i
j
t TECHNICAL EVALUATION LETTER REPORT l
ON THE THIRD 10-YEAR INSERVICE INSPECTION INTERVAL RE00ESTS FOR RELIEF IES UTILITIES INC.
CENTRAL IOWA POWER COOPERATIVE I CORN BELT POWER COOPERATIVE l
DUANE ARNOLD ENERGY CENTER l DOCKET NUNBER: 50-331 l
1.0 INTRODUCTION
In a letter dated April 26, 1996, the licensee submitted the Third 10-Year Interval Inservice Inspection Program Plan for the Duane Arnold Energy Center.
By letter dated July 30, 1996, the Nuclear Regulatory Commission (NRC) l requested additional information (RAI) on the submittal. In a letter dated September 30, 1996, IES Utilities submitted a response to the RAI and asked l that Requests for Relief NDE-R022, NDE-R024, NDE-R025, and NDE-R026 be evaluated separately, as they were required for the October 1996 outage. In a letter dated October 3,1996, the licensee provided additional clarification of its submittal and withdrew Request for Relief NDE-R022. In a letter dated ,
October 31, 1996, the licensee withdrew Requests for Relief NDE-R024, NDE-R025, and NDE-R026, and submitted a request to implement an alternative to Code requirements contained in Code Case N-535, Alternative Requirements for l Inservice Inspection Intervals. The Idaho National Engineering Laboratory (INEL) staff has evaluated the subject request in the following section.
2.0 EVALVATION The licensee submitted the subject alternative to Code requirements for
\ implementation in the Third 10-Year Interval Inservice Inspection Program Plan for the Duane Arnold Energy Center. The Code of record for the Duane Arnold ENCLOSURE 2 I
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Energy Center, third 10-year interval, is the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, 1989 Edition.
The information provided by the licensee in support of the request has been evaluated and the basis for disposition is documented below.
Reauest to Imolement the Alternative to Code Reauirements Provided in Code Case N-535. Alternative Reauirements for Inservice Insoection Intervals Code Reauirement: IWA-2430(d) states "For components inspected under Program B, each of the inspection intervals may be extended or decreased by as much as 1 year. Adjustments shall not cause successive intervals to be altered by more than 1 year from the original pattern of intervals."
IWB-2420(a) and IWC-2420(a) state: "The sequence of component examinations established during the first inspection interval shall be repeated during each successive interval to the extent practical."
Licensee's Proposed Alternative: Pursuant to 10 CFR 50.55a(a)(3)(i), the licensee proposes to implement the alternative to Code requirements contained in Code Case N-535, Alternative Requirements for Inservice Inspection Intervals, for the third 10-year interval.
Licensee's Basis for the Proposed Alternative (as stated):
i " Allowing examination for two intervals within the same outage, while not l crediting to the same interval, does not degrade the structural integrity l of the systems / components being examined. It allows the most efficient use of available resources. Radiation exposure can be maintained as low as reasonably achievable (ALARA) by allowing the nozzle welds and inner radii to be scheduled in conjunction with bioshield removal for preforming tLe reactor pressure vessel weld examinations."
i "Use of Code Case N-535 will continue to ensure the structural integrity of the systems / components examined by the DAEC ISI program. Use of the Code Case will not alter the requirements for scheduling inspection intervals. Per IWB-2420(a) and IWC-2420(a), 'The sequence of component examinations established during the first inspection interval shall be l
repeated during each successive inspection interval, to the extent practical.' Thus, an acceptable level of quality and safety will have been achieved and public health and safety will not be endangered by allowing the proposed alternative per Code Case N-535."
Evaluation: The licensee proposes to implement alternatives contained in Code Case N-535, Alternative Requirements for Inservice Inspection Intervals, for the third 10-year interval. Code Case N-535 allows the licensee to perform the examinations scheduled in a subsequent interval in conjunction with the completion of examinations scheduled for a current interval when the outage is within one-year of the start of the subsequent interval. However, this Code Case does not allow examinations performed to complete a current interval examination program to be credited to both intervals.
The alternatives of Code Case N-535 complement the examination scheduling flexibility provided in IWB-2411(b) and IWB-2412(b), that states, "The inspection period specified in (a) above may be decreased or extended by as much as 1 year to enable an inspection to coincide with a plant outage within the limitations of IWA-2430(d)." IWA-2430(d) states, "For components inspected under Program B, each of the inspection interval may be extended or decreased by as much as 1 year. Adjustments shall not cause successive intervals to be altered by more than 1 year from the original pattern of intervals." As a result, the INEL staff concludes that the frequency between examinations will remain essentially unchanged, potentially varying by no more than one year. In addition, the percentage of examinations required to be completed each period is satisfied. Therefore, verification of the structural integrity of components will be performed with an acceptable frequency, providing an acceptable level of quality and safety.
3.0 CONCLUSION
The INEL staff has reviewed the information provided by the licensee in support of the proposed use of Code Case N-535, Alternative Requirements for Inservice Inspection Inte-vals. Based on this review, the INEL concludes that i
the licensee's proposal to implement alternatives contained in Code Case N-535 will provide an acceptable level of quality and safety by maintaining essentially the same frequency between examinations, varying by no more than one year, and the percentage.of components examined each period as required by Code. Therefore, it is recommended that the proposed alternative be authorized pursuant to 10 CFR 50.55a(a)(3)(i). Use of Code Case N-535 should be authorized for the current interval or until such time as the Code Case is published in a future revision of Regulatory Guide 1.147. At that time, if the licensee intends to continue to implement this Code Case, the licensee is to follow all provisions in Code Case N-535 with limitations issued in Regulatory Guide 1.147, if any.
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