United States Nuclear Regulatory Commission - Protecting People and the Environment

EA-96-414 - Sequoyah 1 & 2 (Tennessee Valley Authority)

December 24, 1996

EA 96-414

Tennessee Valley Authority
ATTN: Mr. Oliver D. Kingsley, Jr.
President, TVA Nuclear and
Chief Nuclear Officer
6A Lookout Place
1101 Market Street
Chattanooga, TN 37402-2801

SUBJECT:  NOTICE OF VIOLATION AND PROPOSED IMPOSITION OF CIVIL
          PENALTIES - $100,000 
          (NRC INSPECTION REPORT NOS. 50-327 AND 50-328/96-13)

Dear Mr. Kingsley:

This refers to the special inspection conducted between September 19 and November 2, 1996 at the Sequoyah facility. The purpose of the inspection was to follow up on the equipment problems experienced during the Unit 2 reactor trip on October 11, 1996, and the maintenance and corrective actions associated with an inoperable Unit 2 reactor trip breaker (RTB) on September 19, 1996. The results of this inspection were sent to you by letter dated November 25, 1996. An open, predecisional enforcement conference was conducted in the Region II office on December 16, 1996, with members of your staff to discuss the apparent violations, the root causes, and corrective actions to preclude recurrence. A list of conference attendees, NRC slides, and a copy of Tennessee Valley Authority's (TVA) presentation materials are enclosed.

Based on the information developed during the inspection and the information that was provided during the conference, the NRC has determined that violations of NRC requirements occurred. The violations are cited in the enclosed Notice of Violation and Proposed Imposition of Civil Penalties (Notice), and the circumstances surrounding them are described in detail in the subject inspection report.

Violations A(1), A(2) and A(3) have been evaluated in the aggregate and assigned a single increased severity level due to the similarity of the corrective action program deficiencies identified as a result of the equipment problems experienced during the trip on October 11, 1996. Violation A(1) involves the failure to identify the root cause and take adequate corrective actions for recurring failures of a main feedwater isolation valve (MFIV) motor brake. This valve has failed to stroke on four previous occasions since 1989. The failure to implement corrective actions to control use of a material susceptible to rapid aging at high temperatures in safety-related and quality-related ASCO solenoid valves is cited in Violation A(2). The failure of a quality-related ASCO valve, which caused excessive reactor coolant pump seal leakage, resulted in the reactor shutdown on October 11, 1996. A number of other valves were subsequently determined to be degraded. In this case, your staff had been alerted by NRC Bulletin 78-14, Generic Letter 91-15 and by a Sequoyah Problem Evaluation Report documenting problems with the material, yet you failed to implement effective corrective action. Violation A(3) involves the failure to adequately implement site procedures described by your corrective action process in that, when a fire system deluge actuation in July 1996 wet plant equipment, your extent of condition review failed to bound the affected equipment, and adequate corrective action was not taken for water intrusion into plant equipment. On October 11, 1996, a turbine runback resulted due to failed turbine impulse pressure switches affected by water intrusion, which caused the need for a manual reactor trip. Operators were also unaware of the interlock between the turbine runback and the locked in auxiliary feedwater (AFW) actuation signal and did not reset the main feedwater pump in order to allow AFW reset.

The NRC is particularly concerned that the apparent root cause of Violations A(1), A(2) and A(3) is the inadequate implementation of your corrective action program. As described in detail in the inspection report, the issues related to Violations A(1), A(2) and A(3) have been known by TVA for some time but were never fully evaluated to determine the extent of condition or the effectiveness of the corrective actions in resolving the root cause of the conditions. Your failure to fully evaluate the cause and adequately correct recurring problems with moisture intrusion and brake corrosion in the MFIV resulted in its failure to close on demand upon receiving a valid feedwater isolation signal. In another case, the corrective action plans for a significant generic issue were never implemented. Other deficiencies in plant material condition were also identified as a result of the October 11, 1996 trip. These deficiencies caused a spurious turbine runback, loss of manual auxiliary feedwater control and a water hammer in the steam dump system which caused damage to piping and hangers. The NRC is concerned that problems experienced in ensuring effective and timely corrective actions at the Sequoyah site, as described in EA 96-269 which was issued on November 19, 1996, are continuing to occur. Therefore, Violations A(1), A(2) and A(3) are classified in the aggregate in accordance with the "General Statement of Policy and Procedures for NRC Enforcement Actions" (Enforcement Policy), NUREG-1600, as a Severity Level III problem.

Violations B(1), B(2) and B(3) have also been evaluated in the aggregate and assigned a single increased severity level because the violations contributed to or were a direct consequence of the underlying problem. Violation B(1) involves inadequate maintenance and testing on a RTB which resulted in installation of an inoperable RTB in Unit 2. Violation B(2) involves the failure to maintain the minimum required channels of the reactor trip P-4 permissive function. The failure to follow plant procedures requiring an evaluation of the operability of the RTB and an assessment of the reportability of the event is cited in Violation B(3).

The root causes of Violations B(1), B(2) and B(3) were poor communications between Operations, Maintenance and Engineering; non-conservative decision-making; training deficiencies; and poor event analysis. These root causes and the following significant concerns indicate inadequate control of licensed activities:

(1) Maintenance supervision made a nonconservative decision to proceed with post maintenance testing of the RTBs when subsequent steps required partial disassembly of RTB components. Inadequate training on RTB maintenance and vendor manual deficiencies also contributed to the violations.

(2) Maintenance and engineering personnel failed to recognize the significance of the rod deviation computer alarm, which was received when the RTB was installed, and failed to understand its potential impact on operability. This was evidenced by a proposal to troubleshoot the RTB problems online and divert resources towards clearing the rod deviation alarm by inserting a "dummy" signal into the computer prior to determining the cause for the signal. These issues should have led management to take prompt action to ensure operability of the RTB prior to exceeding the Limiting Condition for Operation (LCO).

(3) Although Operations was proactive in questioning operability of the RTB, they failed to make a conservative decision to remove the RTB for a number of hours. An early, conservative decision on RTB operability could have precluded a violation of the LCO.

(4) The event critique did not address operability of the refurbished RTB, the functions of the auxiliary contacts, and a deficient revision to the maintenance procedure for lubricating the RTB inertia latch.

(5) The event was not fully evaluated until after prompting by NRC inspectors. TVA staff then conducted a more extensive evaluation and determined that the auxiliary contacts: (1) supplied signals for the reactor trip alarm, high steam flow interrupt, a computer point for the rod deviation program, turbine trip, feedwater isolation; and, (2) allowed blocking of the safety injection (SI) signal after a SI so that the SI signal could be reset. This evaluation revealed the violation of the LCO for the reactor trip P4 permissive and the violation of plant procedures with regard to the operability/ reportability determination.

(6) Operations and the engineering staff did not recognize that the turbine trip contacts on the RTB were part of the P-4 function.

Therefore, Violations B(1), B(2) and B(3) are classified in the aggregate in accordance with the "General Statement of Policy and Procedures for NRC Enforcement Actions" (Enforcement Policy), NUREG-1600, as a Severity Level III problem.

In accordance with the Enforcement Policy, a base civil penalty in the amount of $50,000 is considered for each Severity Level III problem. Because your facility has been the subject of escalated enforcement actions within the last two years1, the NRC considered whether credit was warranted for Identification and Corrective Action in accordance with the civil penalty assessment process described in Section VI.B.2 of the Enforcement Policy. With regard to Violations A(1), A(2) and A(3), the NRC concluded that credit was not warranted for Identification because the violations were revealed through an event. However, credit was warranted for the factor of Corrective Action, based on the extensive corrective actions to improve (1) plant material conditions, (2) management effectiveness, and (3) implementation of the corrective action program. Therefore, application of the civil penalty assessment process resulted in the base civil penalty of $50,000 for the Severity Level III problem.

The NRC concluded that credit was not warranted for Identification of Violations B(1), B(2) and B(3), because the rod deviation alarm provided a reasonable indication of a potential problem and NRC prompted review of several aspects of the underlying issues. With regard to Corrective Action, corrective actions included disciplinary actions, reinforcement of management expectations, and procedural revisions. During the predecisional enforcement conference, you also discussed your site-wide initiatives to improve management ownership and control of plant activities. Based on the above, the NRC determined that credit for the factor of Corrective Action was appropriate. Application of the civil penalty assessment process for Violations B(1), B(2) and B(3) resulted in the base civil penalty of $50,000 for the Severity Level III problem.

Therefore, to emphasize the importance of management oversight of plant activities and the need for prompt effective corrective actions, I have been authorized, after consultation with the Office of Enforcement, to issue the enclosed Notice of Violation and Proposed Imposition of Civil Penalties (Notice) in the amount of $100,000 for the two Severity Level III problems.

An apparent violation was identified in NRC Inspection Report No. 50-327, 328/96-13 for the failure to take adequate corrective actions to prevent flexible conduit damage on the MFIVs. At the predecisional enforcement conference, you indicated that the flexible conduit on the MFIV had not been damaged as originally thought. In addition, you provided additional information on your corrective actions to preclude damage to flexible conduits. This apparent violation is therefore withdrawn.

You are required to respond to this letter and should follow the instructions specified in the enclosed Notice when preparing your response. The NRC will consider your response, in part, to determine whether further enforcement action is necessary to ensure compliance with regulatory requirements.

In accordance with 10 CFR 2.790 of the NRC's "Rules of Practice," a copy of this letter, its enclosures, and your response will be placed in the NRC Public Document Room (PDR).

                            Sincerely,

                            Original Signed by
                            Stewart Ebneter

                            Stewart D. Ebneter
                            Regional Administrator

Docket Nos. 50-327, 50-328
License Nos. DPR-77, DPR-79

Enclosures:
1. Notice of Violation and Proposed Imposition of Civil Penalties
2. Conference Attendees
3. NRC Presentation Materials
4. Licensee Presentation Materials

cc w/encls:

O. J. Zeringue, Senior Vice President
Nuclear Operations
Tennessee Valley Authority
6A Lookout Place
1101 Market Street
Chattanooga, TN 37402-2801

R. J. Adney
Site Vice President
Sequoyah Nuclear Plant
Tennessee Valley Authority
P. O. Box 2000
Soddy-Daisy, TN 37379

General Counsel
Tennessee Valley Authority
ET 10H
400 West Summit Hill Drive
Knoxville, TN 37902

Raul R. Baron, General Manager
Nuclear Assurance and Licensing
Tennessee Valley Authority
4J Blue Ridge
1101 Market Street
Chattanooga, TN 37402-2801

Pedro Salas, Manager
Licensing and Industry Affairs
Tennessee Valley Authority
4J Blue Ridge
1101 Market Street
Chattanooga, TN 37402-2801

Ralph H. Shell, Manager
Licensing and Industry Affairs
Sequoyah Nuclear Plant
P. O. Box 2000
Soddy-Daisy, TN 37379

Michael H. Mobley, Director
Division of Radiological Health
3rd Floor, L and C Annex
401 Church Street
Nashville, TN 37243-1532

County Executive
Hamilton County Courthouse
Chattanooga, TN 37402


NOTICE OF VIOLATION
AND
PROPOSED IMPOSITION OF CIVIL PENALTIES
Tennessee Valley Authority                           Docket Nos. 50-327 and 50-328
Sequoyah Nuclear Plant                               License Nos. DPR-77 and DPR-79
Units 1 and 2                                        EA 96-414 

During an NRC inspection conducted between September 19 and November 2, 1996, violations of NRC requirements were identified. In accordance with the "General Statement of Policy and Procedures for NRC Enforcement Actions," NUREG-1600, the NRC proposes to impose civil penalties pursuant to Section 234 of the Atomic Energy Act of 1954, as amended (Act), 42 U.S.C. 2282, and 10 CFR 2.205. The particular violations and associated civil penalties are set forth below:

A. (1) 10 CFR 50, Appendix B, Criterion XVI requires, in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, defective material and equipment, and nonconformances, are promptly identified and corrected. In the case of significant conditions adverse to quality, the measures shall assure that the cause of the condition is determined and corrective action taken to preclude repetition.

Contrary to the above, the licensee identified a significant condition adverse to quality, i.e., rust in the brake assembly of main feedwater isolation valve (MFIV) 2-MVOP-003-0100-B, but failed to adequately determine the root cause of the rust (water intrusion) and failed to take corrective action to preclude repetition of this significant condition adverse to quality. Specifically, the licensee failed to perform adequate evaluations or take adequate corrective actions for MFIV failures in January 1989, September 1990, September 1994, and April 1995. The failure to preclude repetition of this adverse condition resulted in the failure of MFIV 2-MVOP-003-0100-B to close on October 11, 1996, upon a valid feedwater isolation signal. (01013)

(2) 10 CFR 50, Appendix B, Criterion XVI requires, in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, defective material and equipment, and nonconformances, are promptly identified and corrected. In the case of significant conditions adverse to quality, the measures shall assure that the cause of the condition is determined and corrective action taken to preclude repetition.

Contrary to the above, the licensee identified a significant condition adverse to quality, i.e., degradation of the elastomer material Buna-N when exposed to temperatures greater than 125 degrees Fahrenheit (·F), which resulted in repetitive failures of solenoid valves, but failed to take corrective action to preclude repetition of this significant condition adverse to quality. Specifically, the licensee failed to implement a corrective action plan developed in late 1993 to address issues identified in NRC IE Bulletin 78-14, Deterioration of Buna-N Components in ASCO Solenoids and Generic Letter 91-15, Operating Experience Feedback Report, Solenoid-Operated Valve Problems at United States Reactors, and failed to implement effective corrective actions for Problem Evaluation Report (PER) SQPER930001, which identified previous deficiencies in the operation of ASCO solenoid valves due to degradation of the Buna-N material. On October 11, 1996, a quality-related solenoid operated valve, on a reactor coolant system (RCS) pump seal leak-off isolation valve, failed due to temperature aging of Buna-N material in the valve, which caused initiation of a plant shutdown resulting in a reactor trip. A subsequent licensee investigation identified that a number of safety-related and quality-related valves exposed to temperatures of greater than 125 degrees ·F and containing Buna-N were not evaluated for Buna-N degradation. (01023)

(3) Technical Specification 6.8.1.a requires, in part, that procedures shall be established, implemented, and maintained covering the activities recommended in Appendix A of Regulatory Guide 1.33, Revision 2, February 1978, "Quality Assurance Program Requirements (Operations)." Appendix A of Regulatory Guide 1.33, Section 1, includes administrative procedures.

Site Standard Practice 3.4, Sections 3.3 and 3.4, require, in part, that the Responsible Organization (1) develop the corrective action plan, and (2) implement and/or monitor implementation of the approved corrective action, for conditions documented in Problem Evaluation Reports.

Contrary to the above, the licensee failed to develop an adequate corrective action plan and failed to implement corrective action to ensure that equipment affected by a July 1996 inadvertent fire system deluge actuation, documented in PER SQ961977PER, was surveyed for degradation and refurbished as necessary. As a result, turbine impulse pressure switches PS 47-13B and PS 47-13E were subsequently identified as failed, due to water intrusion. The failed switches caused a spurious turbine runback on October 11, 1996, and complicated recovery from a subsequent reactor trip by inhibiting manual control of the Auxiliary Feedwater System. Subsequent licensee investigation identified 18 other junction boxes affected by water intrusion. (01033)

These violations represent a Severity Level III problem (Supplement I).
Civil Penalty - $50,000.

B. (1) Technical Specification 6.8.1.a requires, in part, that procedures shall be established, implemented, and maintained covering the activities recommended in Appendix A of Regulatory Guide 1.33, Revision 2, February 1978, "Quality Assurance Program Requirements (Operations)." Appendix A of Regulatory Guide 1.33, Section 9, includes procedures for performing maintenance.

Maintenance Instruction (MI)-10.9.1, REACTOR TRIP BREAKER TYPE DB50 INSPECTION ASSOCIATED WITH SYSTEM 99, Revision 16, describes, in part, the steps for lubrication and testing of the reactor trip breaker (RTB) inertia latch.

Contrary to the above, the licensee failed to properly implement procedure MI-10.9.1 and failed to establish adequate procedural steps to ensure complete reassembly of the RTB inertia latch during latch lubrication and appropriate testing of the RTB contacts after it was reassembled. Specifically:

  1. On September 14, 1996, personnel performed two sections of MI-10.9.1 out of sequence. Section 7, Post Performance Activities, was performed prior to the completion of Section 6, Performance, which resulted in completion of the RTB post-maintenance test prior to a step requiring that the auxiliary contact linkage assembly be disconnected from the inertia latch.

  2. Since July 29, 1994, MI-10.9.1, was inadequate in that Step 6.2.6 functionally tested operability of the auxiliary contacts when a subsequent step, Step 6.4.1, required disassembly of the auxiliary contact linkage assembly to allow lubrication of the inertia latch. The procedure did not contain precautions or adequate instructions regarding the disassembly/reassembly of the RTB inertia latch during latch lubrication. The failure to provide adequate instructions for reassembly of the inertia latch resulted in an inoperable P-4 channel. (02013)

(2) Unit 2 Technical Specification 3.3.1, Table 3.3-1, Item 22.G, Reactor Trip, P-4, Action 14, requires that, while in Mode 1, with the number of channels OPERABLE one less than required by the Minimum Channels OPERABLE requirement, be in at least HOT STANDBY within 6 hours.

Contrary to the above, on September 19, 1996 while operating in Mode 1, the number of P-4 channels OPERABLE was one less than required by the Minimum Channels OPERABLE requirement and the licensee failed to place Unit 2 in HOT STANDBY within 6 hours. (02023)

(3) Technical Specification 6.8.1.a requires, in part, that procedures shall be established, implemented, and maintained covering the activities recommended in Appendix A of Regulatory Guide 1.33, Revision 2, February 1978, "Quality Assurance Program Requirements (Operations)."

Site Standard Practice, SSP-3.4, CORRECTIVE ACTION, Revision 17, Appendix E, Step 2.0.D, requires, in part, that if a condition described in a PER potentially affects operability or is potentially reportable, that prompt verbal notification of the condition to the Shift Operations Supervisor (SOS) shall be provided and that the SOS shall promptly receive a copy of the PER.

Contrary to the above, as of September 20, 1996, prompt verbal notification of the condition described in PER SQ962451PER was not provided to the SOS nor did the SOS promptly receive a copy of the PER. As a result, the licensee failed to perform an immediate operability/reportability determination on an inoperable RTB, as required by SSP-3.4, Appendix E, Step 5.0, until October 7, 1996, after being prompted by the NRC. (02033)

These violations represent a Severity Level III problem (Supplement I).
Civil Penalty - $50,000.

Pursuant to the provisions of 10 CFR 2.201, the Tennessee Valley Authority (Licensee) is hereby required to submit a written statement or explanation to the Director, Office of Enforcement, U.S. Nuclear Regulatory Commission, within 30 days of the date of this Notice of Violation and Proposed Imposition of Civil Penalties (Notice). This reply should be clearly marked as a "Reply to a Notice of Violation" and should include for each alleged violation: (1) admission or denial of the alleged violation, (2) the reasons for the violation if admitted, and if denied, the reasons why, (3) the corrective steps that have been taken and the results achieved, (4) the corrective steps that will be taken to avoid further violations, and (5) the date when full compliance will be achieved. If an adequate reply is not received within the time specified in this Notice, an order or a Demand for Information may be issued as to why the license should not be modified, suspended, or revoked or why such other action as may be proper should not be taken. Consideration may be given to extending the response time for good cause shown. Under the authority of Section 182 of the Act, 42 U.S.C. 2232, this response shall be submitted under oath or affirmation.

Within the same time as provided for the response required above under 10 CFR 2.201, the Licensee may pay the civil penalties by letter addressed to the Director, Office of Enforcement, U.S. Nuclear Regulatory Commission, with a check, draft, money order, or electronic transfer payable to the Treasurer of the United States in the amount of the civil penalties proposed above, or may protest imposition of the civil penalties in whole or in part, by a written answer addressed to the Director, Office of Enforcement, U.S. Nuclear Regulatory Commission. Should the Licensee fail to answer within the time specified, an order imposing the civil penalties will be issued. Should the Licensee elect to file an answer in accordance with 10 CFR 2.205 protesting the civil penalties, in whole or in part, such answer should be clearly marked as an "Answer to a Notice of Violation" and may: (1) deny the violations listed in this Notice, in whole or in part, (2) demonstrate extenuating circumstances, (3) show error in this Notice, or (4) show other reasons why the penalties should not be imposed. In addition to protesting the civil penalties in whole or in part, such answer may request remission or mitigation of the penalties.

Any written answer in accordance with 10 CFR 2.205 should be set forth separately from the statement or explanation in reply pursuant to 10 CFR 2.201, but may incorporate parts of the 10 CFR 2.201 reply by specific reference (e.g., citing page and paragraph numbers) to avoid repetition. The attention of the Licensee is directed to the other provisions of 10 CFR 2.205, regarding the procedure for imposing a civil penalty.

Upon failure to pay any civil penalties due which subsequently has been determined in accordance with the applicable provisions of 10 CFR 2.205, this matter may be referred to the Attorney General, and the penalties, unless compromised, remitted, or mitigated, may be collected by civil action pursuant to Section 234c of the Act, 42 U.S.C. 2282c.

The response noted above (Reply to Notice of Violation, letter with payment of civil penalties, and Answer to a Notice of Violation) should be addressed to: Mr. James Lieberman, Director, Office of Enforcement, U.S. Nuclear Regulatory Commission, One White Flint North, 11555 Rockville Pike, Rockville, MD 20852-2738, with a copy to the Regional Administrator, U.S. Nuclear Regulatory Commission, Region II and a copy to the NRC Resident Inspector at the Sequoyah Nuclear Plant.

Because your response will be placed in the NRC Public Document Room (PDR), to the extent possible, it should not include any personal privacy, proprietary, or safeguards information so that it can be placed in the PDR without redaction. 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.

Dated at Atlanta, Georgia
this 24th day of December 1996


1. A Severity Level III violation and proposed civil penalty of $50,000 were issued on November 19, 1996, (EA 95-269) related to fire protection program deficiencies. A Severity Level II violation and proposed civil penalty of $80,000 were issued on February 20, 1996, (EA 95-252) related to employee discrimination in Department of Labor Case Nos. 92-ERA-19 and 92-ERA-34.

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