NRC NEWS

 U.S. NUCLEAR REGULATORY COMMISSION 

 Office of Public Affairs Telephone: 301/415-8200

 Washington, DC 20555-001 E-mail: opa@nrc.gov 

 Web Site: http://www.nrc.gov/OPA

No. 04-055 May 5, 2004

NRC PROVIDES UPDATE ON REVIEW PROCESS

FOR VERMONT YANKEE UPRATE REQUEST

The Nuclear Regulatory Commission today announced it will utilize a new engineering

assessment inspection as part of its review of Entergy Nuclear’s request to increase the power output of

the Vermont Yankee nuclear power plant by 20 percent.

The NRC’s intentions are discussed in the agency’s reply to the Vermont Public Service

Board’s (PSB) request for assurances about Vermont Yankee’s reliability following an uprate. 

Although the NRC’s regulatory authority does not cover reliability specifically, the agency oversees

many safety-related systems and functions that contribute to a plant’s reliable operation.

“The agency remains committed to ensuring continued safe operation of Vermont Yankee. I

have given the Governor my assurances on this,” NRC Chairman Nils Diaz said.

In addition to its substantial uprate review process, the NRC has decided to also conduct a new

engineering design inspection, which has been under development for several months to enhance the

Reactor Oversight Process. The inspection will provide additional information for the NRC and be

responsive to the PSB’s concerns. “The NRC staff considered a number of factors, including the

Board’s request for an independent engineering assessment, and concluded it is appropriate to conduct

this engineering inspection at Vermont Yankee,” Chairman Diaz said.

The NRC will use the new inspection to proactively identify any latent issues in a nuclear

power plant’s design, focusing on those components and systems devoted to safety. The design

inspection will include an evaluation of changes to the plant’s licensing basis to ensure safety margins

remain adequate. At Vermont Yankee, the inspection process will involve three weeks of on-site

inspections and more than 700 hours of direct inspection time.

 The NRC’s inspection team of approximately six will include experienced NRC inspectors,

some of whom have not had recent oversight involvement with Vermont Yankee, and at least two

contractors with experience in reactor design. The agency will share the inspection schedule with

Vermont officials to facilitate state representative participation, as allowed by NRC regulation and

policy.
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The NRC will not approve the Vermont Yankee uprate, or any proposed changes to a reactor’s

license, unless the agency can conclude the changes can be implemented safely. The full text of the

NRC’s letter to the PSB is provided.

###
Mr. Michael H. Dworkin, Chairman

Vermont Public Service Board

112 State Street, Drawer 20

Montpelier, Vermont 05620-2701

Dear Mr. Dworkin:

I am responding on behalf of the U.S. Nuclear Regulatory Commission (NRC) to your letters

dated March 15 and 31, 2004, regarding the request by Entergy Nuclear Vermont Yankee, LLC, and

Entergy Nuclear Operations, Inc. (Entergy), to amend the Vermont Yankee Nuclear Power Station

license to increase the power level of the facility. In those letters, the Vermont Public Service Board

requested that the NRC conduct its review of the proposed power uprate in a way that would provide

Vermont a level of assurance about plant reliability equivalent to an independent engineering

assessment. The NRC has decided to conduct a detailed engineering inspection that we believe will

be appropriate for addressing our oversight responsibilities and is also responsive to the Board’s

concerns. This inspection will be performed as part of a new engineering inspection program that the

NRC has been developing to enhance the Reactor Oversight Process. 

NRC regulations and its oversight process focus on ensuring nuclear safety, whether the

facility is operating at power or shut down. The NRC’s statutory authority does not extend to

regulating the reliability of electrical generation. The NRC recognizes, however, that there is some

overlap between attributes that result in safe operation and those that contribute to overall plant

reliability. 

The Commission understands that the Board is concerned about the reliability of Vermont

Yankee following an increase in power level, especially in light of operational issues that have

occurred at some other plants that have recently implemented extended power uprates. The NRC

recognizes the importance of these issues and is taking steps to ensure that they are satisfactorily

addressed to maintain safety. For example, in response to instances of steam dryer cracking at

some boiling water reactors, outside technical experts are assisting NRC staff in performing an audit

of General Electric's analyses related to steam dryer performance and specific issues related to

Vermont Yankee. We continue to engage the industry to ensure resolution of these issues and will

consider additional regulatory action, if needed.

The NRC’s established review process for power uprate applications is independent,

thorough, and comprehensive. A description of the review process is enclosed. Engineering 

assessments have always been an integral part of the NRC’s safety activities. Under our current

Reactor Oversight Process, NRC resident inspectors and regional specialists routinely evaluate the

work performed by the licensee’s engineering organization to determine whether engineering

analyses adequately support safe operation. Over the past several months, the NRC has been

developing a new engineering inspection program which we intend to pilot at selected plants. The

NRC staff considered a number of factors, including the Board’s request for an independent

engineering assessment, and concluded it is appropriate to conduct this engineering inspection at

Vermont Yankee. This new engineering assessment inspection incorporates the best practices of the

existing and past engineering inspections. The NRC will use this inspection to verify that design

bases have been correctly implemented for a sampling of components across multiple systems and

to identify latent design issues. The inspection process uses operating experience, risk assessment,

and engineering analysis to select risk-significant components and operator actions, and will ensure

that adequate safety margins exist. Although the specific sampling of components is still being

developed, it will include components from multiple systems that are potentially affected by a power

uprate such as the emergency core cooling systems, the containment system, power conversion

systems, and auxiliary systems. The inspection will be performed by a team of approximately six

inspectors, including some NRC inspectors who do not have recent oversight experience with

Vermont Yankee and at least two contractors with design experience. Three weeks of on-site
inspection and over 700 hours of direct inspection time will be conducted. This level of effort exceeds

that of the biennial safety system design inspection. The Commission believes it is appropriate for

addressing the NRC's oversight responsibilities and is also responsive to the Board’s concerns. The

NRC staff will inform the State of Vermont of the schedule for this inspection to facilitate participation

by State representatives, consistent with NRC policy.

The NRC Advisory Committee on Reactor Safeguards (ACRS) will also review the Vermont

Yankee power uprate request. The ACRS is a statutory committee that reports directly to the

Commission and is structured to provide a forum where experts representing many technical

perspectives can provide advice that is factored into the NRC’s decision-making process. The NRC

staff will provide the results of its review efforts, including relevant inspection findings, to the ACRS

for review. After the ACRS completes its review, it will make an independent recommendation

regarding whether the proposed power uprate amendment should be approved.

The NRC will not approve the Vermont Yankee uprate, or any proposed change to a plant

license, unless the NRC staff can conclude that the proposed change will be executed in a manner

that assures the public’s health and safety. In response to your request, the NRC staff has taken a

close look at proposed inspections and technical reviews to ensure that they will identify and address

potential safety concerns for operating at uprated power conditions. The staff has concluded that the

detailed technical review, prescribed in the Extended Power Uprate Review Standard, coupled with

the normal associated program of power uprate and engineering inspections, will provide the

information necessary for the NRC staff to make a decision on the safety of operation of Vermont

Yankee under uprated power conditions. The Commission believes that the results of NRC reviews

and inspections, particularly the new engineering inspection, will assist in addressing the Board’s

concerns regarding the future reliability of Vermont Yankee. The NRC staff is prepared to meet with

the Board to explain further our review process and scope, including the engineering assessment

inspection.

Sincerely,

/RA/

 Nils J. Diaz

Enclosure: 

Established NRC Power Uprate Review Process 
Established NRC Power Uprate Review Process

The NRC’s established review process for power uprate applications is independent, thorough, and

comprehensive. A team of engineers with specialties in a minimum of 17 different technical areas will

review the Vermont Yankee power uprate application. The NRC plans to expend about 4000 hours to

perform a comprehensive assessment of the engineering, design, and safety analyses related to the

uprate. The NRC’s “Review Standard for Extended Power Uprates” guides the staff in its review of

the application. The Review Standard also provides guidance for determining when and what type of

audits should be performed at the plant or vendor sites, as well as for performing our own

confirmatory analyses and independent calculations to supplement the review. 

The NRC’s review of the power uprate application also includes on-site inspections. NRC inspections

will review selected activities and modifications made to allow operation at higher power levels to

verify that changes to plant systems will support safe plant operation and are in accordance with

Vermont Yankee’s licensing and design bases. The NRC will use Inspection Procedure 71004,

“Power Uprates,” as well as a number of our baseline inspection procedures to inspect issues

specifically related to power uprate. These inspections will assess changes that could impact the

integrity of barriers (e.g., higher flow rates which could increase vibration at specific support points),

safety evaluations, plant modifications, post maintenance and surveillance testing, heat exchanger

performance, and integrated plant operation. Additionally, our other baseline inspection activities,

while not specifically directed at power uprate activities, will provide additional information about

Vermont Yankee’s ability to operate safely at a higher power level.

The NRC will adjust, as necessary, our technical review, audit plans, confirmatory analyses, or

inspection activities if any issues are identified which may have a bearing on our decision on the

Vermont Yankee power uprate application. For example, a recent examination of the steam dryer at

Vermont Yankee identified cracks on both interior and exterior structures of the steam dryer. The

steam dryer is an important component in the process for converting steam to electrical energy, but is

not used to mitigate any accidents. The NRC is interested in steam dryer cracking because of the

potential for parts to break loose and impact the performance of safety-related equipment. Entergy

has indicated that the cracks are in low-stress, low-steam flow areas of the dryer and not in the areas

where cracks were observed at other plants that implemented extended power uprates. NRC

inspectors monitored Entergy’s steam dryer inspection activities, and we will thoroughly review

Entergy’s follow-up actions as part of our evaluation of Vermont Yankee’s request to operate at a

higher power level.

Assessment of engineering has always been an integral part of the NRC’s safety mission. In the

1990s, the NRC performed extensive reviews at plants across the country to determine if licensees

were operating plants in accordance with their design bases. As part of this review, two team

inspections were conducted at Vermont Yankee in 1997. One of these inspections was led by staff

from NRC headquarters and included six contractors. In 1998, the NRC conducted an engineering

inspection, as well as a team inspection to address operability issues resulting from Vermont

Yankee’s configuration improvement program. Under our current Reactor Oversight Process, NRC

resident inspectors and regional specialists routinely evaluate the work performed by the licensee’s

engineering organization to determine whether the engineering analyses adequately supports safe

operation. Our inspectors conduct both routine engineering inspections, as well as an in-depth team

inspection every two years. Since the Reactor Oversight Process was implemented in 2000, the NRC

has conducted two such safety system design team inspections. 

Enclosure