Arkansas' experience of a lifetime3 April 2002
Arkansas Nuclear One unit 1 (ANO-1) was the third licence renewal application to be approved by the US Nuclear Regulatory Commission. ANO-1 was the lead plant that Entergy used to test the new regulatory process defined in 10 CFR Part 54. By Garry Young
Arkansas Nuclear One unit 1 (ANO-1) received an operating licence on 21 May, 1974, which was scheduled to expire at midnight, 20 May, 2014. Under US Nuclear Regulatory Commission (NRC) regulations in 10 CFR Part 54 — "Requirements for Renewal of Operating Licenses for Nuclear Power Plants" — ANO-1 was given the option to request the issuance of a renewed operating licence that would allow an additional 20 years of operation. This option was exercised and a renewed operating licence was granted by the NRC on 20 June, 2001, to allow the operation of ANO-1 until the year 2034.
ANO-1, which is located in Russellville, Arkansas, is operated by Entergy Operations, and has a Babcock and Wilcox (B&W) nuclear steam supply system. The unit produces 836MWe and, together with unit 2, the ANO plant provides approximately 33% of Arkansas' electric power needs.
Entergy Operations had a long-standing interest in renewing the ANO-1 operating licence. This interest led to extensive ANO participation in the Babcock and Wilcox Owners Group's (B&WOG's) efforts associated with licence renewal, which began in 1985. In 1992, B&WOG evaluated options for licence renewal and developed a plan for a "generic" licence renewal programme. The Generic License Renewal Program (GLRP) had the goal of providing a viable and economical method for the participating utilities to renew their operating licences. Following the 1995 revision of 10 CFR Part 54, Entergy established a dedicated ANO-1 licence renewal team to prepare the initial licence renewal engineering reports.
In 1998, Baltimore Gas & Electric and Duke Energy submitted the first two licence renewal applications under 10 CFR Part 54. The NRC response to those two applications was encouraging and the resulting NRC reviews were timely and efficient. As a result of the successes of these first two applications, Entergy Operations made the decision in late 1998 to proceed with submission of a licence renewal application for ANO-1. The application was submitted to the NRC on 31 January, 2000, which made the ANO-1 application the third licence renewal application submitted under 10 CFR Part 54.
The renewal effort
The current definition of what is required for licence renewal was not established until 1995, when 10 CFR Part 54 was revised. Therefore, in 1995 the rules were better defined and the process for pursuing licence renewal became more focused.
The ANO team working on licence renewal included a number of personnel who had previously supported the ANO design basis documentation project, including personnel from Framatome-ANP. This experience with design basis documents was a significant factor in accomplishing the effort, since much of the information needed for the licence renewal work is from design basis documents. Approximately 20 people were directly involved in the various parts of the project, but the level of effort for individuals varied considerably during the different phases of the project. The project phases are shown in the Figure on the right.
The cost for the Entergy engineering and environmental work to support the ANO-1 project was approximately $7.7 million. The cost for NRC review fees was an additional $3.3 million. Therefore, the total cost for ANO-1 to obtain a renewed operating licence was approximately $11 million.
Recent industry estimates for completing the licence renewal process indicate that a utility should expect to spend between $10 and $15 million for a renewed licence, take two to three years to prepare an application, and expect an NRC review duration of 24 to 30 months. These estimates are consistent with the first few licencees that have completed the licence renewal process.
10 CFR Part 54 contains the regulatory requirements that must be satisfied in order to obtain a renewed operating licence. NEI 95-10 — "Industry Guidance for Implementing the Requirements of 10 CFR Part 54 - The License Renewal Rule" — provides additional guidance on how to comply with 10 CFR Part 54. The rule contains several requirements that a licencee must complete and document prior to submittal of a renewal application. One of these requirements is to perform an Integrated Plant Assessment (IPA). The IPA must document:
• The systems, structures and components (SSCs) within the scope of 10 CFR Part 54.
• The methods used to identify the SSCs.
• For each structure and component identified, demonstate that the effects of ageing will be adequately managed so that the intended function(s) will be maintained consistent with the current licensing basis (CLB) for the period of extended operation.
The IPA process is shown graphically in the top Figure on page 20 (figures currently not available). In order to complete the IPA, an ageing management review (AMR) must be completed for each set of structures, components, or commodities within the scope of 10 CFR Part 54 that are passive and not subject to periodic replacement. The AMR is performed to identify the applicable ageing effects that must then be managed during the period of extended operation. For ANO-1, the AMR reports serve as a portion of the auditable and retrievable on-site records documenting compliance with 10 CFR Part 54 and their contents were summarised in the licence renewal application. The AMR demonstration that the effects of ageing will be adequately managed is accomplished by:
• Understanding how the structure or component performs its intended function (for example, maintaining a pressure boundary).
• Identifying the ageing effects (such as cracking) that could impair the intended function of the structure or component.
• Identifying the applicable plant programmes that adequately detect and manage the ageing effects.
Two methods of performing AMRs were used at ANO. The first method was to participate in the B&WOG GLRP effort to produce generic AMRs for Class 1 mechanical systems. Upon completion of the generic AMRs, an ANO-specific validation was performed to ensure the applicability of the generic AMR. This method minimised the site-specific work in producing the AMRs and ensured consistency with the other similar B&W plants, such as Oconee.
The second method was to prepare a site-specific AMR for those structures and components that did not have the benefit of a generic AMR. This method was used for the non-Class 1 mechanical AMRs, structural AMRs, and electrical AMRs. These site-specific AMRs presented the biggest challenge to the ANO-1 licence renewal team since there was no generic AMR to cite as the basis for the ANO report. All review work had to be done by the ANO team. However, since the ANO team included personnel with experience on the previous design basis document project, the on-site review work progressed efficiently.
A group of almost 60 engineering reports was created by the ANO team to document the IPA required by 10 CFR Part 54 and other licence renewal related work. This ANO-1 site-specific documentation provided the foundation for the preparation of the ANO-1 licence renewal application.
What happens next?
The lower Figure on page 20 provides a summary of the NRC licence renewal review process. Upon receipt of the ANO-1 application in February 2000, the NRC initiated the formal review process. The duration of this process is set by the NRC at 30 months to allow for all of the activities identified in the Figure. However, one of these activities includes the adjudicatory hearing process. This portion of the NRC review process is only required if a petition for intervention is successfully filed. Interested parties have approximately 60 days to petition for intervention after an application is received by the NRC. For the ANO-1 project, no one filed a petition so this portion of the schedule was eliminated. As a result, in early 2000 the NRC reduced the ANO-1 review schedule to 25 months.
The NRC review process is divided into two major parallel efforts, the safety review and the environmental review. These two reviews proceed somewhat independently of each other, but both must be completed prior to issuance of a renewed licence.
The ANO-1 licence renewal project had several opportunities to achieve review efficiencies since it was the third project to complete an application, it was the second B&W plant to apply (Oconee was the first), and the NRC had provided updated draft guidance based on the experiences they had with Calvert Cliffs and Oconee. The ANO-1 project successfully pursued these opportunities. The result was that in April 2001, the NRC further reduced the review schedule from 25 months down to 17 months. This significant schedule reduction can be attributed in part to the following:
• Use of generic ageing management review information. The ANO-1 application referenced already approved B&WOG generic reports for the reactor coolant system components (Class 1), which allowed the NRC to reference already written safety evaluation reports. In addition, many of the site-specific issues related to the Class 1 components were addressed at ANO-1 in the same manner as the previous B&W applicant, Oconee. This allowed the NRC to reference work already done on Oconee to expedite completion of the review of ANO-1.
• Use of B&WOG mechanical tools and structural tools for ageing management review. Entergy team members were involved in the development of the generic ageing management review guidance documents known as "mechanical tools" and "structural tools". This involvement gave the team members a head start on applying the tools to the ageing management reviews at ANO. These standard guidance documents also allowed personnel without extensive materials backgrounds to perform the site-specific ageing reviews consistently and efficiently. These documents are now available to EPRI members as TR-114881 and report #1003056.
• Participation in owners group and industry group activities during the preparation of the licence renewal application. Entergy's involvement in the B&WOG and in the Nuclear Energy Institute (NEI) and EPRI licence renewal industry group activities was found to be particularly beneficial. For example, NEI worked with the NRC to develop a draft standard format for a licence renewal application in mid-1999. The ANO-1 project team took advantage of the draft and used it to prepare the ANO-1 licence renewal application. This resulted in a much smaller application that focused more on what the NRC indicated they needed to review for licence renewal than previous applications. Entergy's involvement with these industry groups helped overcome the learning curve for this new process.
As shown by the milestone schedule, Entergy was successful in applying lessons learned and in efficiently implementing the licence renewal process to achieve a significant reduction in the review schedule. The receipt of the renewed licence on 20 June, 2001 concluded a process that took just under 17 months.
As a result of the success of the ANO-1 licence renewal project, in June 2000, Entergy entered into a partnership with Framatome-ANP to pursue licence renewal at the other Entergy nuclear power plants. This partnership has the following primary goals:
• To achieve cost reductions by leveraging the experience and knowledge of Entergy and Framatome-ANP resources on future Entergy licence renewal projects.
• To establish dedicated teams that can maximise the learning curve economies inherent in complex activities.
• To seek business opportunities outside of Entergy when the market and internal conditions indicate such opportunities would be mutually beneficial.
The Entergy/Framatome-ANP team has started work on licence renewal for two more Entergy nuclear plants - Pilgrim and ANO-2. In addition, the team has been awarded contracts to assist with licence renewal at the Davis Besse nuclear plant owned by FirstEnergy Corporation and the Donald C Cook nuclear plant owned by American Electric Power Company. Since forming this partnership, the Entergy/Framatome-ANP team has grown into the largest provider of licence renewal services within the USA. Building on the successes at ANO-1, the Entergy/Framatome-ANP team expects to further reduce the cost and schedule for licence renewal projects in the future.