United States Nuclear Regulatory Commission - Protecting People and the Environment

EA-00-137 - Oconee 1, 2, & 3 (Duke Energy Corporation)

November 9, 2000

SDP/EA-00-137

Duke Energy Corporation
ATTN: Mr. W. R. McCollum
              Vice President
               Oconee Nuclear Station
7800 Rochester Highway
Seneca, SC 29672

SUBJECT: FINAL SIGNIFICANCE DETERMINATION FOR A WHITE FINDING AND NOTICE OF VIOLATION (NRC INSPECTION REPORT 50-269/00-011, 50-270/00-011, AND 50-287/00-011, OCONEE NUCLEAR STATION)

Dear Mr. McCollum:

The purpose of this letter is to provide you with the final results of our significance determination of the preliminary White finding identified in the subject inspection report. The inspection finding was assessed using the significance determination process and was preliminarily characterized as White (i.e., an issue with low to moderate increased importance to safety, which may require additional NRC inspections). This White finding involved the reduced ability to provide reactor coolant makeup following tornados of such intensity that the 4160 volt electrical buses within the turbine building and the Borated Water Storage Tank are damaged (without damaging the Keowee hydro-electric units), accompanied by the failure of the Standby Shutdown Facility either through independent failure or due to the tornado. In the postulated dominant accident sequences, the licensee's analysis assumed that a High Pressure Injection (HPI) pump taking suction from the spent fuel pool (SFP) would provide a success path to prevent core damage. However, around 1990, a performance deficiency involving a design calculation resulted in Duke Energy Corporation's (DEC) failure to recognize that the SFP would be available for a time significantly less than the originally assumed mission time.

At your request, an open regulatory conference was conducted with you and members of your staff on September 7, 2000, to discuss your views on this issue. Enclosure 2 lists the attendees at the regulatory conference. Enclosures 3 and 4 contain copies of the material presented by DEC and the NRC at the regulatory conference, respectively. During the meeting, your staff described your assessment of the significance of the findings and detailed corrective actions, including the root cause evaluations. DEC's risk assessment determined that the increase in core damage frequency (CDF) for Oconee Unit 1 was approximately 3E-6 per year. The increase in CDF for Units 2 and 3 was approximately 5E-7 per year. DEC stated that the increase in risk for Units 2 and 3 was less because these units have a different reactor coolant pump (RCP) seal package that is less susceptible to a seal failure. DEC agreed that the pertinent design calculation was in error, but also stated that the Oconee design and licensing bases do not include consideration of a RCP seal loss of coolant accident (LOCA).

After considering the information developed during the inspection and the information you provided at the conference, the NRC has concluded that the inspection finding for Oconee Unit 1 is appropriately characterized as White. DEC's risk assessment is also consistent with this characterization. In addition, as you indicated at the regulatory conference, there is a difference in the type of RCP seals for Units 2 and 3. The NRC accepts DEC's position that this difference results in a reduced core damage frequency to a value approximated by DEC at the conference. As such, this issue is appropriately characterized as Green (i.e., an issue of very low safety significance) for Units 2 and 3.

You have ten business days from the date of this letter to appeal the staff's determination of significance for the identified White finding. Such appeals will be considered to have merit only if they meet the criteria given in NRC Inspection Manual Chapter 0609, Supplement 3.

The NRC has also determined that your failure to adequately consider design inputs to assure that the design basis was translated into specifications, drawings, procedures, and instructions for the HPI system using the SFP as a suction source following a tornado is a violation of 10 CFR 50, Appendix B, Criterion III, Design Control. The violation is cited in the enclosed Notice of Violation (Notice), and the circumstances surrounding it are described in detail in the subject inspection report. The NRC accepts DEC's position that a tornado induced RCP seal LOCA is outside the design basis of the facility. However, scenarios exist within the design basis of the facility which would require the SFP as a suction source for the HPI pump. As such, DEC's failure to adequately consider thermal-hydraulic design inputs into design calculations represents a violation of 10 CFR 50, Appendix B, Criterion III, Design Control. In accordance with the "General Statement of Policy and Procedure for NRC Enforcement Actions - May 1, 2000," NUREG-1600 (Enforcement Policy), the Notice is considered escalated enforcement action because it is associated with a White finding.

The NRC has concluded that information regarding the reason for the violation, the corrective actions taken and planned to correct the violation and prevent recurrence, and the date when full compliance was achieved is already adequately addressed on the docket in DEC's presentation materials provided at the regulatory conference (Enclosure 3). Therefore, you are not required to respond to this letter unless the description herein does not accurately reflect your corrective actions or your position. In that case, or if you choose to provide additional information, you should follow the instructions specified in the enclosed Notice.

Because plant performance for this issue has been determined to be in the increased regulatory response band, we will use the NRC Action Matrix to determine the most appropriate NRC response for this finding. We will notify you, by separate correspondence, of that determination. In assessing this issue, the NRC recognizes that the vulnerability that resulted in the increased risk existed before 1990 is not reflective of DEC's current performance, the vulnerability was identified by your staff in 1998, and actions have been or will be implemented by DEC to address the vulnerability. Nonetheless, these factors do not change the overall risk significance of the issue and are not mitigating under the current Reactor Oversight Program (ROP). You should be aware, however, that at the end of the first year of implementation of the ROP, the program will be evaluated for lessons learned from initial implementation, including the appropriateness of the various assessment process outcomes.

In accordance with 10 CFR 2.790 of the NRC's "Rules of Practice," a copy of this letter and its enclosures, and your response (if you choose to provide one), will be available electronically for public inspection in the NRC Public Document Room (PDR) or from the Publicly Available Records (PARS) component of NRC's document system (ADAMS). To the extent possible, your response should not include any personal privacy, proprietary, or safeguards information so that it can be placed in the PDR and PARS without redaction. ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public NRC Library).

Sincerely,

/RA/

Luis A. Reyes
Regional Administrator

Docket Nos. 50-269, 50-270, 50-287, 72-04
License Nos. DPR-38, DPR-47, DPR-55, SNM-2503

Enclosures:
1. Notice of Violation
2. List of Attendees
3. Presentation material presented by DEC
4. Presentation material presented by NRC

cc w/encls:

Compliance Manager (ONS)
Duke Energy Corporation
Electronic Mail Distribution

L. A. Keller, Manager
Nuclear Regulatory Licensing
Duke Energy Corporation
526 S. Church Street
Charlotte, NC 28201-0006
Lisa Vaughn
Legal Department (PB05E)
Duke Energy Corporation
422 South Church Street
Charlotte, NC 28242

Peggy Force
Assistant Attorney General
N. C. Department of Justice
Electronic Mail Distribution
Rick N. Edwards
Framatome Technologies
Electronic Mail Distribution

Anne Cottingham
Winston and Strawn
Electronic Mail Distribution

Mel Fry, Director
Division of Radiation Protection
N. C. Department of Environmental
   Health & Natural Resources
Electronic Mail Distribution

Virgil R. Autry, Director
Div. of Radioactive Waste Mgmt.
S. C. Department of Health and
  Environmental Control
Electronic Mail Distribution

R. Mike Gandy
Division of Radioactive Waste Mgmt.
S. C. Department of Health and
  Environmental Control
Electronic Mail Distribution

County Supervisor of
Oconee County
415 S. Pine Street
Walhalla, SC 29691-2145

Lyle Graber, LIS
NUS Corporation
Electronic Mail Distribution


NOTICE OF VIOLATION

Duke Energy Corporation
Oconee Nuclear Station
Units 1, 2 and 3
Docket Nos. 50-269, 50-270, 50-287, 72-04
License Nos. DPR-38, DPR-47, DPR-55,  
                       SNM-2503
SDP/EA-00-137

During an NRC inspection conducted on June 28, 2000, a violation of NRC requirements was identified. In accordance with the "General Statement of Policy and Procedure for NRC Enforcement Actions - May 1, 2000," NUREG-1600, the violation is listed below:

10 CFR 50, Appendix B, Criterion III, Design Control, states in part that measures shall be established to assure that applicable regulatory requirements and the design basis are correctly translated into specifications, drawings, procedures, and instructions, and that design control measures shall be applied to items such as stress, thermal, hydraulic and accident analysis.
Updated Final Safety Analysis Report, Section 3.2.2, states in part that a sufficient supply of primary side makeup water is assured during a tornado initiated loss of offsite power by several backup systems.
   a.    The SSF Reactor Coolant Makeup Pump can take suction from the Spent Fuel Pool. The pump can be supplied power from the SSF Diesel.

   b. A High Pressure Injection Pump can take suction from either the Borated Water Storage Tank or the Spent Fuel Pool. Either the "A" or "B" High Pressure Injection Pump can be powered from Keowee via the Auxiliary Service Water Pump Swithchgear.

Duke Topical Report 1-A states that the quality assurance program meets the requirements of ANSI 45.2.11 - 1974, "Quality Assurance Requirements for the Design of Nuclear Power Plants."
ANSI 45.2.11, Section 3.2.4 states in part that design inputs include design conditions such as pressure and temperature and, Section 3.2.11 states that hydraulic requirements such as pump net positive suction head, allowable pressure drops, and allowable fluid velocities are design inputs.
Contrary to the above, as of April 1, 2000, measures had not been adequately established to assure that applicable regulatory requirements and the design basis were correctly translated into specifications, drawings, procedures, and instructions, in that pressure, temperature or hydraulic requirements had not been adequately considered as design inputs for calculation OSC 3873, "Hydraulic Model of High Pressure Injection System with Suction from the Fuel Pool." (01013)

This violation is associated with a White SDP finding.

The NRC has concluded that information regarding the reason for the violation, the corrective actions taken and planned to correct the violation and prevent recurrence, and the date when full compliance was achieved is already adequately addressed on the docket in an enclosure to this letter transmitting this Notice of Violation (Notice). However, you are required to submit a written statement or explanation pursuant to 10 CFR 2.201 if the description therein does not accurately reflect your corrective actions or your position. In that case, or if you choose to respond, clearly mark your response as a "Reply to a Notice of Violation," and send it to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555 with a copy to the Regional Administrator, Region II within 30 days of the date of the letter transmitting this Notice.

If you contest this enforcement action, you should also provide a copy of your response, with the basis for your denial, to the Director, Office of Enforcement, United States Nuclear Regulatory Commission, Washington, DC 20555-0001.

Because any response will be made available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records (PARS) component of NRC's document system (ADAMS), to the extent possible, it should not include any personal privacy, proprietary, or safeguards information so that it can be made available to the public without redaction. ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public NRC Library). If personal privacy or proprietary information is necessary to provide an acceptable response, then please provide a bracketed copy of your response that identifies the information that should be protected and a redacted copy of your response that deletes such information. If you request withholding of such material, you must specifically identify the portions of your response that you seek to have withheld and provide in detail the bases for your claim of withholding (e.g., explain why the disclosure of information will create an unwarranted invasion of personal privacy or provide the information required by 10 CFR 2.790(b) to support a request for withholding confidential commercial or financial information). If safeguards information is necessary to provide an acceptable response, please provide the level of protection described in 10 CFR 73.21.

In accordance with 10 CFR 19.11, you may be required to post this Notice within two working days.

Dated this 9th day of November 2000


LIST OF OPEN REGULATORY CONFERENCE ATTENDEES

NUCLEAR REGULATORY COMMISSION:
L. Reyes, Regional Administrator, Region II (RII)
B. Mallett, Deputy Regional Administrator, RII
C. Casto, Director, Division of Reactor Safety, RII
V. McCree, Deputy Director, Division of Reactor Projects (DRP), RII
R. Borchardt, Director, Office of Enforcement, OE
A. Boland, Enforcement Officer, RII
S. Sparks, Senior Enforcement Specialist, RII
C. Ogle, Chief, Branch 1, DRP, RII
W. Rogers, Senior Reactor Analyst, DRS, RII
M. Shannon, Senior Resident Inspector, Oconee, DRP, RIIL
C. Evans, Regional Counsel, RII
R. Carroll, Jr., Project Engineer, Branch 1, DRP, RII
J. Lenahan, Senior Reactor Inspector, Engineering Branch, DRS, RII
R. Schin, Senior Reactor Inspector, Engineering Branch, DRS, RII
D. Nelson, Senior Enforcement Specialist, OE (teleconference)
V. Ordaz, Senior Enforcement Coordinator, NRR, (teleconference)
D. LaBarge, Senior Project Manager, Office of Nuclear Reactor Regulation (NRR) (teleconference)
R. Emch, Chief, Project Directorate II, Division of Licensing Project Management, NRR, (teleconference)
P. Koltay, Inspection Program Branch, NRR, (teleconference)
P. Wilson, Probablistic Safety Assessment Branch, NRR, (teleconference)

DUKE ENERGY CORPORATION:
W. McCollum, Oconee Vice President
M. Nazar, Engineering Manager
L. Nicholson, Regulatory Compliance Manager
E. Burchfield, Design Supervisor
D. Brewer, Risk Analysis Manager

Enclosure 2


ENCLOSURE 3
PRESENTATION MATERIAL PRESENTED BY DEC
Is ADAMS accessible from the NRC Web site at
http://www.nrc.gov/reading-rm/adams.html (the Public NRC Library).
The accession number is ML 003768658.


OPEN REGULATORY CONFERENCE

OCONEE NUCLEAR STATION

SEPTEMBER 7, 2000, 1:00 P.M.
NRC REGION II OFFICE, ATLANTA, GEORGIA

I. OPENING REMARKS AND INTRODUCTIONS
   L. Reyes, Regional Administrator

II. NRC REGULATORY CONFERENCE POLICY
   A. Boland, Enforcement Officer

III. EMPHASIS ON MEETING INTENT
   L. Reyes, Regional Administrator

IV. STATEMENT OF THE ISSUE WITH CURRENT RISK & VIOLATION PERSPECTIVE
   C. Casto, Director, Division of Reactor Safety

V. LICENSEE RISK & REGULATORY PERSPECTIVE PRESENTATION

VI. BREAK / NRC CAUCUS
   L. Reyes, Regional Administrator

VII. CLOSING REMARKS
   L. Reyes, Regional Administrator

Enclosure 4


STATEMENT OF APPARENT VIOLATION

10 CFR 50, Criterion III, Design Control, states in part that "Measures shall be established to assure that applicable regulatory requirements and design basis ... are correctly translated into specifications, drawings, procedures, and instructions ... Design control measures shall be applied to items such as ... stress, thermal, hydraulic and accident analysis ... "

Updated Final Safety Analysis Report, section 3.2.2, states in part that "... a sufficient supply of primary side makeup water is assured during a tornado initiated loss of offsite power by several backup systems.

c. The SSF Reactor Coolant Makeup Pump can take suction form the Spent Fuel Pool. The pump can be supplied power from the SSF Diesel.

d. A High Pressure Injection Pump can take suction from either the Borated Water Storage Tank or the Spent Fuel Pool. Either the "A" or "B" High Pressure Injection Pump can be powered from Keowee via the Auxiliary Service Water Pump Swithchgear."

Duke Topical Report 1-A states that the quality assurance program meets the requirements of ANSI 45.2.11 - 1974, "Quality Assurance Requirements for the Design of Nuclear Power Plants."

ANSI 45.2.11, section 3.2.4 states in part that design inputs include design conditions such as pressure and temperature and, section 3.2.11 states that hydraulic requirements such as pump net positive suction head, allowable pressure drops, and allowable fluid velocities are design inputs.

As of April 1, 2000, measures had not been adequately established to assure that applicable regulatory requirements and design basis were correctly translated into specifications, drawings, procedures, and instructions in that pressure, temperature or hydraulic requirements had not been adequately considered as design inputs for calculation OSC 3873, "Hydraulic Model of High Pressure Injection System with Suction from the Fuel Pool."

Note: The apparent violation discussed at this Regulatory Conference is subject to further review and is subject to change prior to any resulting enforcement action.

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