ML15118A298
| ML15118A298 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 06/05/1998 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML15118A297 | List: |
| References | |
| 50-269-98-03-01, 50-269-98-3-1, 50-270-98-03, 50-270-98-3, 50-287-98-03, 50-287-98-3, EA-98-199, NUDOCS 9806160491 | |
| Download: ML15118A298 (42) | |
Text
.Duke Energy Corporation Docket Nos. 50-269 and 50-270 Oconee 1 and 2 License Nos. DPR-38 and DPR-47 EA No.98-199 During an NRC'inspection conducted on March 2 - 6 and March 16 - 20, 1998, a violation of NRC requirements was identified. In accordance with the "General Statement of Policy and Procedure for NRC Enforcement Actions," NUREG-1600, the violation is listed below:
10 CFR 50.59 states that changes in the facility as described in the safety analysis report may be made without prior Commission approval, unless the change involves an unreviewed safety question. A proposed change, test, or experiment shall be deemed to involve an unreviewed safety question (USQ) if the probability of a malfunction of equipment important to safety previously evaluated in the safety analysis report may be increased. The licensee shall maintain records of changes in the facility made pursuant to this section. These records must include a written safety evaluation which provides the bases for determination that the change does not involve a USQ. It further states that the licensee shall submit an application for amendment of his license pursuant to 10 CFR 50.90 for a change, test or experiment which-involves a USQ.
Section 3.11.4 of the UFSAR states that redundant air conditioning and ventilation equipment is provided for the control area to assure that no single failure of an active component within these systems will prevent proper control area environmental control.
Section 9.4.1.2.1 of the UFSAR states that the control room zone included the Control Room and the Unit 1 and 2 Electrical Equipment and Cable Rooms.
Contrary to the above, as of March 11, 1998. a USQ, due to an increase in probability of a malfunction of equipment important to safety previously evaluated in the safety analysis report, was not identified in the licensee's safety evaluations for the 1984 Nuclear Station Modification NSM 2324, which isolated the redundant Unit 1 and 2 control room ventilation and air conditioning system from the Unit 1 and 2 electrical equipment and cable rooms. As a result, failure of a single fan could cause loss of cooling to the cable room, resulting in an increase in probability of tripping of safety-related breakers and the potential loss of all equipment required to mitigate an accident. In addition, the licensee did not submit an application for amendment of their license pursuant to 10 CFR 50.90 for a change which involved a USQ.
This is a Severity Level IV Violation.(Supplement I).
9D6 AOCK4' 980605 PDR ADOCIK 05000269 G
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2 Pursuant to the provisions of 10 CFR 2.201, Duke Energy Corporation is hereby required to submit a written statement or explanation to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, D.C. 20555 with a copy to the Regional Administrator, Region II, and a copy to the NRC Resident Inspector, Oconee Nuclear Station, within 30 days of the date of the letter transmitting this Notice of Violation (Notice). This reply should be clearly marked as a "Reply to a Notice of Violation" and should include for each violation: (1) the reason for the violation, or if contested, the basis for disputing the violation or severity level, (2) the corrective steps that have been taken and the results achieved, (3) the corrective steps that will be taken to avoid further violations, and (4) the date when full compliance will be achieved. Your response may reference or include previous docketed correspondence, if the correspondence adequately addresses the required response. 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. Where good cause is shown, consideration will be given to extending the response time.
If you contest this enforcement action, you should also provide a copy of your response to the Director. Office of Enforcement, United States Nuclear Regulatory Commission, Washington, D.C. 20555-0001.
Under the authority of Section 182 of the Act, 42 U.S.C. 2232, this response shall be submitted under oath or affirmation.
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, 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 5th day of June 1998
LIST OF ATTENDEES NUCLEAR REGULATORY COMMISSION L. Reyes, Regional Administrator. Region II J. Jaudon. Director, Division of Reactor Safety, RII A. Boland, Director, Enforcement and Investigations Coordination Staff (EICS).
RII C. Casto, Deputy Director, Division of Reactor Projects (DRP), RII B. Mallett, Deputy Director, Division of Reactor Safety (DRS), Rh C. Ogle, Chief, Reactor Projects Branch (RPB)1, DRP, RII K. Landis, Chief, Engineering Branch (EB), DRS, RII C. Evans, Regional Counsel, RII R. Bernhard, Senior Reactor Analyst, DRS, RII R. Schin, Acting Chief, RPB 3, DRP, RII N. Merriweather, Reactor Inspector, EB, DRS, RII S. Sparks. Senior Enforcement.Specialist, EICS. RII D. LaBarge, Project Directorate 11-2, Nuclear Reactor Regulation (NRR)*
J. Lee, Emergency Preparedness and Radiation Protection Branch, NRR*
J. Raval, Plant Systems Branch, NRR*
M. Tschiltz, Office of Executive Director for Operations*
- Participated by Telephone Duke Enerqv Corporation W. McCollum, Vice President, Oconee Site J. Burchfield, Regulatory Compliance Manager M. Nazar, Engineering Manager P. Newton, Duke Legal
NRC PREDECISIONAL ENFORCEMENT CONFERENCE OCONEE NUCLEAR STATION MAY 19, 1998 I.
OPENING REMARKS AND INTRODUCTIONS L. Reyes. Regional Administrator II. NRC ENFORCEMENT POLICY A. Boland. Director. Enforcement and Investigation Coordination Staff III.
SUMMARY
OF THE ISSUES L. Reyes. Regional Administrator IV. STATEMENTS OF CONCERNS / APPARENT VIOLATIONS J.
Jaudon. Director, Division of Reactor Safety V.
LICENSEE PRESENTATION VI.
BREAK / NRC CAUCUS VII. NRC FOLLOW UP QUESTIONS VIII. CLOSING REMARKS L. Reyes, Regional Administrator
2 A. (EEI 98-03-04) 10 CFR 50.59 states that changes in the facility as described in the safety analysis report may be made without prior Commission approval, unless the change involves an unreviewed safety question. A proposed change, test, or experiment shall be deemed to involve an unreviewed safety question (USQ) if the probability of a malfunction of equipment important to safety previously evaluated in the safety analysis report may be increased.
Section 3.11.4 of the UFSAR states that redundant air conditioning and ventilation equipment is provided for the control area to assure that no single failure of an active component within these systems will prevent proper control area environmental control.
Section 9.4.1.2.1 of the UFSAR states that the control room zone included the Control Room and the Unit 1 and 2 Electrical Equipment and Cable Rooms.
As of March 11, 1998, a USQ. due to an increase in probability of a malfunction of equipment important to safety previously evaluated in the safety analysis report, was not identified in the licensee's safety evaluations for the 1984 Nuclear Station Modification NSM 2324, which isolated the redundant Unit 1 and 2 control room ventilation and air conditioning system from the Unit 1 and 2 electrical equipment and cable rooms. As a result, failure of a single fan could cause loss of cooling.to the cable room, resulting in an increase in probability of tripping of safety-related breakers and the potential loss of all equipment required to mitigate an accident.
NOTE:
The apparent violations discussed in this predecisional enforcement conference are subject to further review and subject to change prior to any resulting enforcement decision.
3 B. (EEI 98-03-05) 10 CFR 50.71(e) requires that the updated Final Safety Analysis Report (UFSAR) be revised to include the effects of all changes in the facility as described in the FSAR. It further requires that the UFSAR be updated within 24 months of making changes to the facility.
As of November 18. 1997, the licensee failed to ensure that Figure 9-24, Control Room Area Ventilation and Air Conditioning System drawing, which was contained in the updated FSAR, was revised within 24 months to reflect changes made in the facility by a 1984 modification NSM ON-2324 that separated the Unit 1 and 2 Control Room Ventilation and Air Conditioning System from.the Unit 1 and 2 Electrical Equipment and Cable Rooms.
NOTE:
The apparent violations discussed in this predecisional enforcement conference are subject to further review-and subject to change prior to any resulting enforcement decision.
Oconee Nuclear Station o
E Nucd~
Predecisional Enforcement Conference May 19, 1998 Oconee Nuclear Site
Agenda
- Apparent Violations
- Sequence of Events
- Potential Prior Opportunities
- Root Cause
- Corrective Actions
- Safety Significance
- CRVS Initiatives
> Technical
> Licensing
- Closing Remarks Oconee Nuclear Site 2
Mu Apparent Violations
- Inadequate 50.59 evaluation on 1984 CRVS modification
- 0 Sequence of Events
- Original CRVS Design
> Non-safety industrial grade system
> Specific control room pressurization criteria not identified
> Air communication between Control Room, Equipment Rooms, and Cable Rooms for Units 1 and 2
> Single active failure proof design for control area cooling
> Not single failure proof for filtration and pressurization
>> Unit 3 design is different
- Control Room is isolated from Cable and Equipment Rooms
- Unit 3 has always been designed for single active failure with respect to control area cooling Oconee Nuclear Site 4
Control Area Cooling - Original Design From Booster From Booster Fan Fan AHU AHU UN TS 1/2 CONTROL ROOM Cable Room Cable Room AHU UNIT I UNIT 2 AHU CABLE CABLE At ROOM ROOM i
Eqmt Room UNIT I UNIT 2 Eqmt Room AHU EQUIPMENT EQUIPMENT AHU ROOM ROOM Oconee Nuclear Site 5
Sequence of Events
- NUREG-0737 issued in 1980
- UFSAR update rule effective in 1980
- First updated FSAR issued in 1982
- Implemented 1984 modification to improve Control Room pressurization
>> Control room cooling separated from Cable and Equipment room cooling
>> Modification resulted in single active failure vulnerabilities for cable room ventilation on Units 1 and 2
>> Modification did not reference Section 3.11 of Oconee UFSAR
>> Modification not in conformance with Section 3.11 of Oconee UFSAR
>> UFSAR figure not updated in 1984 for the modification Oconee Nuclear Site 6
e 0 Control Area Cooling - Current Design From Booster From Booster Fan Fan DO-AHU AHU UNITS 1/2 CONTROL ROOM Cable Room Cable Room AHU AHU UNIT I UNIT 2 CABLE CABLE ROOM ROOM EqmiRoom UNIT I UNIT 2 EqmtRoom AHU EQUIPMENT EQUIPMENT AHU ROOM ROOM Oconee Nuclear Site7
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~
I,0 Sequence of Events
- UFSAR Section Owners identified in mid-1996
- Section owner review initiated in late 1996
Sequence of Events
- Validation of OSRDC PIP in March 1998 questioned the design requirements for control area cooling
- Based on a review of the original FSAR, the single active failure UFSAR non-conformance was self-identified on March 10, 1998 e Immediately began assessing operability
- Operability evaluation concluded control area cooling was inoperable and Technical Specification 3.0 was entered on March 11, 1998
- Compensatory measures immediately implemented to address operability implications Oconee Nuclear Site 9
EReOS Control Area Cooling Compensatory Actions
'le Rude From Booster From Booster Fan Fan AHU AHU UNITS 1/2 CONTROL ROOM Failed Cable Room Cable Room UNIT I
)pnUNIT 2AH CABLE Doors CABLE Close Fire Damper Eqmt Room UNIT I UNIT 2 EqmtRoom AHU EQUIPMENT
- --w EQUIPMENT AHU ROOM ROOM Oconee Nuclear Site 10
__ Potential Prior Opportunities s~
MudC
- Factors relevant to prior opportunities to identify the single failure issue from 1984-1997:
>> Interpretation of "control area" prior to 1998 was different
- Control Room ventilation can withstand a single active failure
>> Literal maintenance of the UFSAR prior to 1996 was not fully appreciated Systematic reviews not implemented during this time period
- Significant process enhancements since 1996
- Potential opportunities in 1997 to identify the single failure vulnerability
>> UFSAR figure update
>> OSRDC PIP Oconee Nuclear Site
Potential Prior Opportunities
- UFSAR figure update in 1997
>> Figure discrepancy was self-identified by UFSAR section owner in March 1997 Engineer's actions were appropriate in addressing a figure discrepancy
>> Potential design issue not readily apparent as a result of figure correction Oconee Nuclear Site 12
Potential Prior Opportunities "eNudt t
- OSRDC PIP resolution from June 1997 to February 1998 focused on design requirements for control room dose analyses
>> PIP resolution reviewed single failure requirements for control room pressurization and filtration
> Scope of PIP did not include a review of control area cooling single failures
- Questioning attitude of engineer during SSEI and a more thorough review of the original FSAR identified control area cooling single failure issue Oconee Nuclear Site 13
Root Cause - Inadequate 50.59
- Oversight in that 50.59 safety evaluation in 1984 did not review all applicable sections of UFSAR
>> Most of CRVS design information is in Section 9 of UFSAR
>> Single active failure design criterion for control area cooling is in Section 3 of UFSAR
>> Section 9 of the UFSAR did not reference Section 3 of the UFSAR Oconee Nuclear Site 14
Review of Current 50.59 Process
'~NudC
- Current 50.59 process is significantly enhanced beyond 1980's process:
> Directive incorporated industry guidance and operating experience
> Searchable electronic UFSAR
>> 50.59 Qualified Reviewer and Preparer training
> Design features review checklist
> 1997 NRC inspection concluded current process is clear Oconee Nuclear Site 15
Review of Past 50.59 Evaluations
%M uce
- Audited 59 random 50.59 safety evaluations for modifications prior to 1989
- Sample size selected to be statistically significant
- Focus of review was to determine if other modifications had incorrect 50.59 evaluations Review determined that the conclusions of the 59 random 50.59 safety evaluations were correct
- Performed review of PIPs related to 50.59s and concluded there was no adverse trend
- Duke's review concluded programmatic changes to the 50.59 process are not warranted in light of this specific violation Oconee Nuclear Site 16
Specific Corrective Actions
- Inadequate 50.59 Apparent Violation
> Completed:
- Performed Operability evaluation assuming a single active failure
- Implemented compensatory measures to assure adequate cooling of Units 1 and 2 Cable and Equipment Rooms in the event of a single active failure
- Implemented Selected Licensee Commitment to address taking components out of service
- Revised UFSAR to clarify single failure requirements and control area cooling definition Oconee Nuclear Site 17
Specific Corrective Actions
- Inadequate 50.59 Apparent Violation
>> Planned:
- Implement modification to resolve CRVS single active failure non-conformance by August 31, 1998
- Revise DBD to address control area cooling single failure requirements by June 1998
- Complete formal single active failure analysis for control area cooling by May 1998 Oconee Nuclear Site 18
Corrective ctions to Prevent Recurrence
- Inadequate 50.59 Apparent Violation
>> Planned:
- Identification of UFSAR discrepancies by the UFSAR reverification initiative will be completed by December 31, 1998
- UFSAR reverification project scope changes
- Review major modifications for obvious UFSAR errors Oconee Nuclear Site 19
ER C Corrective Actions to Prevent
,4 Recurrence
- Inadequate 50.59 Apparent Violation
>> Planned:
- Enhance SITA process to ensure a review of 50.59s for past modifications
- Specific example of control area 50.59 will be reviewed in the Engineering Support Continuing Training Program Oconee Nuclear Site 20
VEft Root Cause 'Untimely UFS Update INUd
- Oversight in 50.59 in 1984 did not identify the figure change in Section 9
- Clear ownership of UFSAR sections and figures was not established prior to 1996
> Structured process for identifying UFSAR discrepancies not in place until owners were established
- Figure discrepancy was self-identified Oconee Nuclear Site 21
R4 Review of Current UFSAR Update Process
- Section owners were identified in 1996
- Special section owner review conducted in 1996-1997
- Significant revisions to UFSAR update process implemented in March 1997
> Expectations for section owners clearly established
> Section owners periodically review their sections and figures to assure accuracy
> Sensitivity to UFSAR evidenced by four times as many UFSAR change packages than last year
- Review concluded current process is sound Oconee Nuclear Site 22
Specific Corrective Actions
- Untimely update of UFSAR Apparent Violation
> Completed:
- Incorrect UFSAR Figure 9-24 change package withdrawn pending CRVS cooling modification
> Planned:
- Revise UFSAR to reflect planned CRVS cooling modification Oconee Nuclear Site 23
Corrective ctions to Prevent Recurrence
- Untimely Update of UFSAR Apparent Violation
>> UFSAR Reverification Project includes a review of figures
- Identification of UFSAR discrepancies by the UFSAR Reverification Project will be completed by December 31, 1998 Oconee Nuclear Site 24
Safety Significance
- Safety concern is the continued reliability of safety related equipment due to elevated temperatures in the cable rooms and equipment rooms
- Low safety significance based on ample time to detect and address single failures
- Fission product barriers and offsite dose consequences not directly impacted by this issue Oconee Nuclear Site 25
Safety Significance
- Detailed analysis of cooling requirements was performed
- Temperatures within Cable Rooms acceptable for at least 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> assuming no compensatory actions
> Vital electrical equipment operability would not be impacted during the first 2 days
- Ample time existed to identify Cable Room cooling problems and restore required cooling
> Procedural requirements were in place to check the status of Cable Room and Equipment Room cooling Oconee Nuclear Site 26
'COER 4
CRVS Initiatives (Technical)
- Control Area Cooling
- Implement modification to address single failure issue
- Revise instrument uncertainty calculations to address loss of cooling
- Control Room Pressurization and Filtration
>> Completed:
- Inspected and repaired control room doors for leakage
- Revised EOP to start booster fans after ES signal or a tube rupture Smoke tested and sealed identified leaks in CRVS duct Sealed all external CRVS ductwork/housings
- Developed training for control room personnel on the use of KI
- Modified PMT for work on CRVS to require leak testing Separated power supplies to booster fan inlet dampers Completed sealing of control room boundary Oconee Nuclear Site 27
CRVS Initiatives (Technical)
- Control Room Pressurization and Filtration
> Planned:
- Perform test to determine effects of single failures on control room pressurization by September 1998 and make appropriate changes
- Quantify current CRVS unfiltered inleakage using tracer gas by September 1998
- Develop long term surveillance for CRVS pressure boundary Oconee Nuclear Site 28
CRVS Initiatives (Technical)
- Control Room Pressurization and Filtration
>> Complete design study for enhancements related to control room habitability
> Oconee will meet with the staff in November 1998 to discuss the results of the study Oconee Nuclear Site 29
QA Classification
- Oconee has concluded that both control room pressurization and control area cooling will be included in the voluntary QA-5 program Oconee Nuclear Site 30
~0 ~ER o
QA Classification Me rudt~
- Correspondence between Duke and NRC shows a common understanding that the system is not QA-1
- Per the April 12, 1995 letter, Oconee' s review concluded no upgrade to QA-1 for CRVS was required Control room pressurization and filtration are not direct support systems for the QA-1 systems in Section 3.1.1 of the UFSAR
- Control area cooling is not a direct support system because it does not immediately or directly affect operability of systems in Section 3.1.1 of UFSAR Oconee Nuclear Site 31
QA Classification Me Pude~
- OSRDC Review of CRVS
>> Results of accident mitigation review
- Control Room pressurization is required and was identified as a system to be included in QA-5
- Control Room, Cable Room, and Equipment Room cooling is required
- Due to extended time to reach temperature limits, control area cooling was not initially identified as a candidate for QA-5 Oconee Nuclear Site 32
CRVS Initiatives (Licensing)
- Provided the staff a March 30, 1998 letter on the Oconee CRVS licensing basis
- Control Area Cooling
>> UFSAR changed to clarify control area cooling
>> SLC implemented for Control Area Cooling
>> Tech Spec submittal by August 1, 1998
- Control Room Pressurization and Filtration
>> Following completion of the design study, Duke will meet with the staff to discuss:
- Design requirements for the system
- Tech Spec changes for control room pressurization and filtration
- Resolution of UFSAR non-conformances Oconee Nuclear Site 33
Management Perspective
- The inadequate 50.59,safety evaluation is significant
- Both apparent violations self-identified
- Actions in the past did not present reasonable opportunities to have identified the violations
- Immediate corrective actions implemented to address operability
- Prompt initiation of comprehensive corrective actions to resolve non-conforming UFSAR conditions
- Discretion is warranted based on our voluntary initiative to identify and correct UFSAR noncompliances
> Scope of UFSAR accuracy review expanded based on lessons learned Oconee Nuclear Site 34
~~0
'COW~ER~f Management Perspective M~
udC~
- NRC CRVS SSEI and ONS SITAs clearly demonstrate the value of continued assessments of the design basis
- Significant resources continue to be applied to Oconee design basis and UFSAR initiatives
- New initiatives being identified using a risk-informed process
- Low threshold for the identification and resolution of design basis questions
- Applying significant resources to resolve issues as they are identified Oconee Nuclear Site 35
-00 Closing Remarks Oconee Nuclear Site 36