September 29, 2005

MEMORANDUM TO: Luis A. Reyes

Executive Director for Operations

FROM: J. E. Dyer, Director /RA by R. W. Borchardt for/

Office of Nuclear Reactor Regulation

Carl J. Paperiello, Director /RA/

Office of Nuclear Regulatory Research

SUBJECT: SEMIANNUAL REPORT - STATUS OF IMPLEMENTATION OF

DAVIS-BESSE LESSONS LEARNED TASK FORCE REPORT

RECOMMENDATIONS

By memorandum dated March 7, 2003, the Office of Nuclear Reactor Regulation (NRR) and the

Office of Nuclear Regulatory Research (RES) submitted an overall plan for implementation of

the recommendations of the Davis-Besse Lessons Learned Task Force (LLTF) by the

U.S. Nuclear Regulatory Commission (NRC). The plan requires semiannual reports on the

status of implementation of all LLTF recommendations. This is the fifth status report, covering

the period from March to August 2005. 

During this period, we continued to make substantial progress and the initial actions to address

48 of the 49 LLTF recommendations are now complete. The one remaining recommendation is

being addressed by industry initiatives to update the reactor pressure vessel (RPV) head

inspection requirements in the American Society of Mechanical Engineers (ASME) Code. 

Appropriate inspection requirements will be incorporated into NRC regulations. The RPV

inspection requirements, currently required by First Revised Order EA-03-009 (the order), are

adequate until the completion of this remaining item.

The following discussion summarizes the significant activities in each of the four major

categories during this report period. The attached table contains detailed information on the

current status of implementation of all Davis-Besse LLTF recommendations.

1. Assessment of Stress Corrosion Cracking

Activities related to RPV head inspection included continued monitoring of licensee outage

inspection results pursuant to the order, following up on plants that discovered defects, and

evaluating requests for alternatives to the order. NRC inspectors reviewed licensee inservice

inspection activities and boric acid corrosion control (BACC) programs using the revised

inspection procedures developed in response to the LLTF recommendations.

CONTACT: Brendan T. Moroney, NRR/DLPM

415-3974
L. Reyes - 2 -

The interim requirements of the order continued to provide adequate protection of public health

and safety while the staff monitored the efforts of the ASME to develop alternative requirements

for inspection of RPV upper heads and upper head penetrations during refueling outages. The

industry moved forward on several items during this period. In June 2005 the ASME Board on

Nuclear Codes and Standards approved Code Case N-729, which provides additional

inspection requirements for RPV upper heads. The ASME Board on Nuclear Codes and

Standards also approved Code Case N-722, which recommends bare metal visual examination

of all ASME Code Class 1 Alloy 600/82/182 components at frequencies that depend on the

component location temperature. ASME fully accepted both code cases during the August

2005 ASME Code meetings. We expect the ASME to formally publish these code cases by

December 2005. The staff is developing a basis for incorporating these code cases into

Title 10 of the Code of Federal Regulations (10 CFR), Part 50.55a. The inclusion of Code

Case N-729, with conditions, into the amended 10 CFR 50.55a will inform the decision to

rescind the order. The final rule is expected to be published in FY07.

Separately, a meeting to discuss actions for lower RPV head and associated penetration

inspections is scheduled for September 29, 2005. This discussion will assist staff in the

regulatory assessment of ASME Code Case N-722's lower RPV head inspection

recommendations. In addition to the ASME activities to develop Code Case N-729, the Electric

Power Research Institute Materials Reliability Project is developing alternative visual inspection

and evaluation guidelines. This initiative is expected to be completed by the end of 2006. 

2. Assessment of Operating Experience

The revised operating experience program based on Management Directive 8.7, “Reactor

Operating Experience Program,” and the associated handbook have been implemented in draft

form since January 2005. The program establishes a clearinghouse to systematically collect,

communicate, and evaluate operating experience information. Also, a task group is performing

a benchmarking review to identify best practices consistent with regional programs and to

strengthen the interface between the clearinghouse and other technical organizations.

The new program has advanced the use of information technology in making operating

experience information available to internal users and members of the public. There is a new 

database for managing all reported events, as well as a new operating experience information

gateway that consolidates a large collection of individual databases and Web sources of

information onto a single Web access page. It is also easier for the public to search operating

experience in generic communications, event reports, morning reports, and preliminary

notifications. A new communication tool to promptly notify NRC staff members of new

operating experience in their areas of expertise or practice has been developed. Users may

also use this tool to examine recent or emergent operating experience in their respective areas. 

The office is in the process of creating teams of technical staff by October 2005 to automatically

receive and systematically assess the operational data in the team members’ specialized areas

to identify trends and recommend appropriate action.

3. Evaluation of Inspection, Assessment, and Project Management Guidance

The staff completed a review of 80 previously deleted inspection procedures to determine if any 

should be reactivated. This action was, essentially, an effectiveness review of the previous
L. Reyes - 3 -

decision, as recommended by the LLTF. Four inspection procedures were determined to have

continuing applicability and were reactivated. 

Inspection Manual Chapter (IMC) 0040, which governs changes to the Inspection Manual, was

revised in February 2004 to ensure that inspection requirements developed in response to a

generic issue are not inadvertently removed when making subsequent changes. A look-back

period of 4 years was established by the February 2004 revision. An effectiveness review of

the change in August 2005 determined that no requirements had been inadvertently deleted,

and also identified a procedure improvement that will enable historical tracking of generic

issues beyond 4 years. IMC 0040 will be updated by February 2006 to incorporate these

improvements. 

The team formed to develop an agency-wide corrective action program is creating a program

that will institutionalize the agency's most important lessons learned by applying a rigorous and

formal process to the development and closeout of the associated corrective actions. Program

definition and draft documentation are scheduled to be developed by December 31, 2005. 

Following a pilot program and staff training, the base program is scheduled to be implemented

by June 2006. A status report on the program development effort was provided to the

Commission by memorandum on July 22, 2005. In addition, the team is creating a list of

previous lessons learned reports containing significant recommendations for the agency. The

program offices will be asked to perform effectiveness reviews on selected samples from this

list to verify that the original corrective actions are still effective. Additional reviews may be

assigned depending on the results obtained from this sample. This effort will also be used to

organize information about these lessons learned reports so that it can be more easily

accessed and used by the staff in the future. 

On the office level, existing processes are being used to address corrective actions. For

example, within NRR, the process improvement program was revised to serve as the office

corrective action program. Office Instruction ADM-101, Revision 1, “Office of Nuclear Reactor

Regulation Corrective Action Program,” was issued in March 2005. The NRR corrective action

program leverages existing programs to capture lessons learned in one place and establishes a

requirement for effectiveness reviews of completed corrective actions. Specific items that were

identified for additional followup in the effectiveness review of previous lessons learned reports

have been entered into the NRR corrective action program and will be tracked to completion by

that process. 

4. Assessment of Barrier Integrity Requirements

A working group of NRR and RES staff completed an evaluation to examine whether the NRC

should revise RCS leakage limits and require plants to install enhanced leakage detection

equipment. The staff identified techniques that could improve localized leak detection and

online monitoring. The staff also identified several possible improvements to leakage detection

requirements that could provide increased confidence that plants are not operated at power

with reactor coolant pressure boundary leakage. However, implementing these increased

capabilities would likely result in only a very modest reduction in loss-of-coolant accident

frequencies. As a result, the staff concluded that the risk reduction would not justify the costs
L. Reyes - 4 -

of installing and maintaining such equipment (i.e., the cost-benefit criteria for applying the

backfit rule, 10 CFR 50.109, could not be satisfied) and recommended no further action.

Nevertheless, even small leaks that are below Technical Specifications limits could result in

large boric acid deposits if left for long periods, such as a complete plant operating cycle

between refueling outages. Currently, actions to address leakage vary among licensees. 

Therefore, the staff is monitoring a pressurized-water reactor Owners Group initiative to

develop a uniform method for calculating RCS leakage and is working with other industry

groups that are developing uniform responses to RCS leakage. In addition, the implementation

of ASME Code Case N-722, which specifies bare metal visual inspection requirements for all

dissimilar metal welds in the RCS, will limit the amount of boron in containment that might

otherwise accumulate from one outage to the next. Finally, staff audits have verified that

licensees are implementing BACC programs that look for evidence of RCS leakage, and have

been sensitized to look for smaller amounts of boron as part of these programs. Despite these

positive activities, there continue to be examples of boric acid accumulation inside containment. 

The staff is considering follow up activities, potentially through a generic communication, to

address this issue. 

A second working group of NRR and RES staff addressed the recommendation to evaluate the

adequacy of analysis methods for assessing risk of passive component degradation and

integrating the results of the analyses into the regulatory decisionmaking process. In general,

the group found that the methods used to assess risk are adequate; however, in most cases

there is insufficient data to use these methods alone to produce robust results. Also, an

understanding of the limitations and uncertainties of any risk assessment method is crucial for

responsible risk-informed regulatory decisionmaking. The available risk assessment models by

themselves are usually inadequate to provide strong support for many types of decisions. The

inability of the risk models to predict degradation rates and structural integrity effects and the

limited information about plant-specific conditions often make it difficult to make reliable

predictions very far beyond the latest available measurements. However, the group concluded

that decisions made on the basis of a proper combination of inspection results and predictive

modeling can be successfully used to adequately control the risk to the public and

recommended training on incorporating risk assessment results in regulatory decisionmaking. 

The staff expects to complete training and an effectiveness review by September 2006.

The staff continued its participation with industry representatives in the working group that

evaluates improvements to the Reactor Oversight Process (ROP) performance indicators (PIs). 

In particular, the staff participated in a subgroup formed to assess the feasibility of creating a PI

to track the number, duration, and rate of primary system leaks that have been identified but not

corrected. The group concluded that creation of a new PI is not feasible at present, partly

because it is hard for licensees to determine small leak rates accurately and partly because the

quarterly data reporting makes it hard for the staff to determine the number, rate, and duration

of leaks. However, the staff will continue to follow progress in leak detection capability and

industry efforts in this area. As part of the ongoing effort to improve the ROP and the PIs, the

staff is working with external stakeholders, and an NRC staff/industry subgroup has been

established to explore possible improvements in the RCS leakage PI. 
L. Reyes - 5 -

Other Activities

As part of the original implementation plan, action plans were developed to track the

high-priority LLTF recommendations in each of the four categories. All activities in the action

plans for operating experience, inspection and project management, and barrier integrity have

been completed and the final updates of these plans were included in the Director’s Quarterly

Status Reports (DQSR) in April and July 2005. The action plan to address stress corrosion

cracking will remain open to track follow-up regulatory actions resulting from completion of the

LLTF recommendations regarding the staff analysis of nozzle cracking and boric acid corrosion

experience, and the changes to ASME Code inspection requirements. 

As previously reported, the original plan was augmented to include effectiveness reviews

subsequent to the completion of initial LLTF actions - typically, approximately 1 year after

completion. The staff determined that effectiveness reviews are appropriate for 31 of the

49 LLTF recommendations. Eighteen effectiveness reviews have been completed. In general,

the actions were found to be effective in responding to the LLTF recommendations. Revisions

to inspection program guidance will continue to be evaluated in the annual ROP

self-assessments. The staff also plans to enter the LLTF recommendations into the NRR

corrective action program, which has a provision for annual effectiveness reviews of a sample

of completed actions. 

As directed in the staff requirements memorandum dated December 15, 2004, the staff

developed a summary report on the significant improvements that resulted from the LLTF. The

report was posted on the NRC public Web site in June 2005.

Summary

In summary, only one LLTF recommendation remains open. It will be closed when industry

initiatives to improve RPV inspection requirements in the ASME code are completed. The

current inspection requirements of the order are adequate to ensure public safety until the

revised ASME guidelines are subsequently incorporated into NRC regulations. 

Attachment: Status of LLTF Recommendations
L. Reyes - 5 -

Other Activities

As part of the original implementation plan, action plans were developed to track the

high-priority LLTF recommendations in each of the four categories. All activities in the action

plans for operating experience, inspection and project management, and barrier integrity have

been completed and the final updates of these plans were included in the Director’s Quarterly

Status Reports (DQSR) in April and July 2005. The action plan to address stress corrosion

cracking will remain open to track follow-up regulatory actions resulting from completion of the

LLTF recommendations regarding the staff analysis of nozzle cracking and boric acid corrosion

experience, and the changes to ASME Code inspection requirements. 

As directed in the staff requirements memorandum dated December 15, 2004, the staff

developed a summary report on the significant improvements that resulted from the LLTF. The

report was posted on the NRC public Web site in June 2005.

Summary

In summary, only one LLTF recommendation remains open. It will be closed when industry

initiatives to improve RPV inspection requirements in the ASME code are completed. The

current inspection requirements of the order are adequate to ensure public safety until the

revised ASME guidelines are subsequently incorporated into NRC regulations. 

Attachment: Status of LLTF Recommendations

DISTRIBUTION:

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Package No.: ML052380149

ADAMS Accession No: ML052380066 Attachment: ML052380141 NRR-106

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DATE 08/30/05 08/30/05 08/30/05 08/30/05 09/29 /05 09/28/05

OFFICIAL RECORD COPY
SUBJECT: SEMIANNUAL REPORT - STATUS OF IMPLEMENTATION OF DAVIS-BESSE

LESSONS LEARNED TASK FORCE REPORT RECOMMENDATIONS

Dated: September 29, 2005

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