ML20198T127
| ML20198T127 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 10/30/1997 |
| From: | Reyes L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Ohanlon J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| References | |
| NOED-97-2-002, NOED-97-2-2, NUDOCS 9711140203 | |
| Download: ML20198T127 (4) | |
Text
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w October 30, 1997 NOED NO. 97-2-002 Virginia Electric and Power Company ATTN:
Mr. J. P. O'Hanlon Senior Vice President - Nuclear Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen. VA 23060
SUBJECT:
NOTICE OF ENFORCEMENT DISCRETION FOR VIRGINIA ELECTRIC AND POWER COMPANY REGARDING NORTH ANNA (UNIT 1)
Dear Mr. O'Hanlon:
By enclosed letter dated C tober 28, 1997. you requested that the Nuclear Regulatory Commission (NRC) exercise discretion not to enforce compliance with the actions required in Unit 1 Technical Specification (TS) 3.8.1.1 Action b.
This TS requires that with one Emergency Diesel Generator (EDG) inoperable.
" restore the diesel generator to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />." Your letter decumented information previously discussed with the NRC in a telephone conversation on October 28 at 1:00 3.m.
You stated that on October 29, 1997, at 8:18 3.m. Unit I would not 3e in compliance with TS 3.8.1.1 Action b and t1erefore, shutdown of Unit I would be required. The TS action statement was entered at 8:18 p.m. on October 26, 1997.
You requested that a Notice of Enforcement Discretion (NOED) be issued pursuant to the NRC's policy regarding exercise of discretion for an operating facility, set out in Section VII.C. of the " General Statement of Policy and Procedures for NRC Enforcement Actions" (Enforcement Policy). NUREG-1600, and be effective from 8:18 p.m. on October 26. 1997, to 8:18 p.m. on November 2.
1997.
The condition which necessitated the request for discretion was a result of problems encountered during planned testing on the 1H EDG.
Specifically, a catastrophic failure of an engine driven cooling fan blade caused damage to the remainder of the fan blades and the radiator.
You stated that an evaluation and analysis are being performed to establish the root cause of the fan blade failure.
You requested a one-time extension of the allowed outage time for the 1H EOG from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, which is allowed in TS 3.8.1.1 Action b. to seven days to complete repairs, which includes replacement of all fan blades and several radiator compartments and performance of post-maintenance testing.
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In requesting the NOED your safety rationales for extension of the allowed outage time were:
- 1) the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report does not increase: 2) a single train of emergency safeguards equipment is adequate to mitigate the consequences of any previously analyzed accident: 3) new accident precursors or limiting single
. failures are not created: and 4) the margin of safety as defined in the basis for any TS are not reduced.
In addition, you stated that your Probabilistic Safety Assessment (PSA) model indicated an acceptable configuration risk for the increased allowed outage time.
As compensatory measures, actions will be taken to ensure the Alternate A. C.
Diesel Generator will be operable and capable of being connected to the 1H Emergency Bus: the 2J EDG will be maintained operable and capable of being cross tied to the 1H Emergency Bus: the IJ EDG and emergency safeguards equipment will be maintained operable: switchyard and reserve station service transformer activities that ccuid cause any unstable offsite or onsite power conditions will not be scheduled; and refresher training will be provided to the control room operators responsible for restoring power to the 1H Emergency Bus using existing approved procedures.
The staff has reviewed the above safety rationales regarding a one-time extension to the allowed outage time.
The safety rationales and your compensatory measures provide the appropriate justification to support a conclusion that enforcement discretion should be granted to avoid undesirable transients as a result of forcing compliance with the TS. and thus would minimize potential safety consequences and operational risks.
1 On the basis of the staff's evaluation of your request, including the compensatory measures described above, the staff has concluded that an NOED is warranted because we are clearly satisfied that this action involves minimal or no safety impact and has no adverse radiological impact on public health and safety.
Therefore, it is our intention to exercise discretion not to enforce compliance with TS 3.8.1.1 Action b for the period from 8:18 p.m. on October 29, 1997, to 8:18 p.m. on November 2. 1997.
However, this enforcement discretion is contingent u)on the continued belief that acceptable spare parts to complete repair of 1H EX3 are available.
If. during the additional allowed outage time of this discretion.1 J find that the spare parts currently in your possession are not acceptable for use, this enforcement discretion is terminated, after which you must immediately comply with Action b of TS 3.8.1.1.
In addition. if the 1H EDG is returned to operable status before the expiration of this discretion, the discretion will be terminated at the time the 1H EDG is returned to operable status. This letter documents our telephone conversation on October 29, 1997, at 1:00 p.m., during which we orally granted this Notice of Enforcement Discretion.
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However, as stated-in the Enforcement Policy action will normally be taken, to the extent that violations were involved, for the root cause that led to the noncompliance for which this NOED was necessary.
Sincerely, tub
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Luis A. Reyes Regional Administrator Docket No.: 50-338 License No.: NPF-4
Enclosure:
VEPC0 letter dated October 28, 1997 cc w/ encl:
J. H. McCarthy. Manager Nuclear Licensing and Operations Support Virginia Electric & Power Company Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen. VA 23060 W. R. Matthews. Manager North Anna Power Station P. O. Box 402 Mineral. VA 23117 D. A. Christian. Manager i
Surry Power Station Virginia Electric & Power Company 5570 Hog Island Road Surry, VA 23883 Executive Vice President Old Dominion Electric Cooperative 4201 Dominion Boulevard Glen Allen, VA 23060 Dr. W. T. Lough Virginia Cor) oration Commission Division of inergy Regulation P. O. Box 1197 Richmond, VA 2320f cc w/ encl:
Continued see page 3 y
VEPC0 4
cc w/ encl: Continued J. Jeffrey Lunsford County Administrator Louisa County P. O. Box 160 Louisa VA 23093 Michael W. Maupin. Esq.
Hunton and Williams Riverfront Plaza. East Tower 951 E. Byrd Street Richmond, VA 23219 Attorney General Supreme Court Building 900 East Main Street Richmond, VA 23219 Robert B. Strobe. M.D., M.P.H.
State Health Comissioner Office of the Commissioner Virginia Department of Health P. O. Box 2448 Richmond, VA 23218 Distr bution w/ encl:
N. Ka'yanam. NRR R. Gibbs. Rll P. Fillion. Rll D. Jones. RII W. Stansberry, Ril C. Payne. Ril PUBLIC NRC Resident Inspector U.S. Nuclear Regulatory Commission 1024 Hale Mineral. y Drive VA 23117 NRC Resident Inspector U.S. Nuclear Regulatory Corraission Surry Nuclear Power Station 5850 Hog Island Road Surry, VA 23883 eE-Mail James Lieberman. OE (E Mail address:
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October 28, 1997 Mr. Luis Reyes Serial No.:
97-636 Regional Administrator NL&OS/ETS R7 U. S. Nuclear Regulatory Commission Docket No.:
50-338 Region 11 License No.:
NPF-4 Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, Georgia 30303
Dear Mr. Reyes:
VIRGINIA ELECTRIC AND__POWEB COMPANY NORTH ANNA POWER STATION UNITJ EMERGENCY DIESFL_ GENERATOR REPAIRS l
REQUEST FOR ENF?MCEMENT.DISCRETIO.N Pursuant to 10 CFR Part 2, Appendix C, Virginia Electric and Power Company (Virginia Power) requests the NRC to exercise enforcement discretion regarding compliance with Technical Specifications 3.8.1.1, Action b Emergency Diesel Generator allowed outage l
time. The enforcement discretion will permit continued operation beyond the current 72 I
hour allowed outage time for an inoperable Emergency Diesel Generator (EDG). During routine testing of the 1H Emergency Diesel Generator, the engine driven cooling fan catastrophically failed rendering the 1H EDG inoperable. Therefore, in order to avoid I
unnecessary plant transients (e.g., a plant shutdown and startup), Virginia Power is requesting enforcement discretion to permit continued operation of Unit 1 with the 1H EDG inoperable for up to seven days to repair and restore the EDG to operable status.
Discussion At 2018 hours0.0234 days <br />0.561 hours <br />0.00334 weeks <br />7.67849e-4 months <br /> on October 26,1997, during routinc maintenance /ts: ting of the 1H EDG a b;Mo in the engine driven cooling fan catet pi6cally failed causing significant damage to the remalnaer of ine fan blades and the radiator. In order to retum the EDG to opeinble status, it is necessary to replace all of the fan blades and repair or replace I
several of the radiator sections. The extensive amourst of work required to remove and replace interferences, replace all the fan blades, replace several of the radiator sections, and perform post maintenance testing will cause the physical maintenance activities to extend beyond the current 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowed cutage time. Therefore, we are requesting a one-time extension of the allowed outage time for the 1H EDG from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to seven days.
Enclosure
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o A rosiew ofIindustry operating experience was performed to determine whether other plants with.similar EDG's had experienced cooling fan blade failures.
The review determined that there were no similar failures for EDGs that were air cooled. The manufacturer was also contacted and they were not aware of any sirnilar failures.
Virginia Power is currently performing a root cause evaluation of the fan blade failure. It is currently believed that one fan blade failed and caused damage to the other fan blades. Additional evaluation and analysis are being performed to establish the root cause of the fan blade failure.
The enforcement discretion will permit the 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowed outage time to be extended to seven days. The extended allowed outage time will expire upon retuming the 1H EDG to operable status or on November 2,1997 at 2018 hours0.0234 days <br />0.561 hours <br />0.00334 weeks <br />7.67849e-4 months <br />. If the 1H EDG is not retumed to operable status during the above timeframes, North Anna Unit 1 will initiate
- a plant shutdown in accordance with Technical Specification 3.8.1.1 Action b. ' Adoption of the approved line-item improvements to the Technical Specifications or the improved Technical Specifications (ITS) would not have obviated the need for the enforcement discretion since the ITS allowed outage. time for en EDG remains at 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
The compensatory measures, the justification for the duration of the request, the significant hazards consideration, and the evaluation of the potential impact on the environment are discussed in the following sections..
SAFETY IMPACT AND POTENTIAL CONSEQUENCES Continued operation duing the one-time extended allowed outage time of the 1H EDG does not increase the probability of occurrence or the consequences of an accident or malfunction of equ!pment important to safety previously evaluated in the safety analysis report. The Inoperability of an EDG does not affect the probability of any accident previously analyzed. During the one-time extended allowed outage time for the 1H EDG, the remaining train of emergency power (1J emergency bus) and emergency safeguards equipment will remain operable to mitigate the consequences of any previously analyzed accident. A single train of emergency safeguards equipment is adequate to mitigate the consequences of any previously analyzed accident.
Furthermore, compensatory measures will ensure power is available to the 1H emergency bus in the event of an accident or transient which requires emergency powering of the 1H bus.
The proposed'one time extension of the Technical Specifications allowed outage time does not create the possibility of an accident or malfunction of a different type than any evaluated previously in the safety analysis report. The one-time extended alloweo outage time of the 1H EDG does not create any new accident precursors, or limiting single failures. The UFSAR accidents are analyzed assuming that the EDG is the v orst L
single failure. No new initiators result from the change. Therefora, it is concluded that
. no new or different kind of accident from any previously evaluated has been created by the one timc extended allowed outage time for the 1H EDG.
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The one-time extended allowed outage time of the 1H EDG does not result in a reduction in margin of safety as defined in the basis for any Technical Specifications.
The compensatory measures provide additional assurance that power Will be available for the 1H emergency bus in the event of an accident or transient which requires emergency powering of the 1H bus.
An exp!! cit PSA model solution was performed in accordance with the guidance contained in the PSA Applications Guide, EPRI TR 105396, which indicated an acceptable configuration risk for an increased allowed outage time. The increase in CDF for a one-time seven day allowed outa0e time for the 1H EDG was less than the acceptance criterion. The On-Line Maintenance Configuration Matrix will be used to control the planned configurations entered while in this seven day period.
COMEENSATORY MEAS 1!BES The following compensatory measures will be taken to provide additional assurance that the public health and safety will not be adversely affected by this enforcement discretion request.
During the extended outage time for the 1H EDG the following actions will be taken to ensure the 1H Emergency Bus can be powered if necessary to support safety equipment necessary to mitigate the consequences of an accident or transient:
The Altemate A.C. Diesel Generator (AAC DG) will be operable and capable of being connected to the 1H Emergency Bus.
The opposite unit's EDGs will be maintained operable with the 2J EDG capable of being cross tied to the 1H Emergency Bus.
The Unit 1J EDG and ernergency safeguards equipment will be maintained operable.
Switchyard / reserve station service transformer activities that could cause any unstable offsite or onsite power conditions will not be scheduled.
Refresher training will be provided to the control room operators responsible for restoring power to the 1H Emergency Bus using existing approved procedures.
S1GNIFICANT HAZARDS _ CONSIDER ATION_
The proposed enforcement discretion for the Technical Specifications describec' above does not result in a significant hazards consideration as defined in 10 C:R 50.92.
Specifically, the proposed enforcement discretion does not:
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Involve a significant increase in the probability or consequences of an accident previously evaluated. The inoperability of an EDG does not affect the probability of any accident previously analyzed.
During the one-time extended allowed
outage time for the 1H EDG, the remaining train of emergency power (1J
. emergency bus) and emergency safeguards equipment will remain operable to mitigate the consequences of any previously analyzed accident. A single train of emergency safeguards equipment is adequate to mitigate the consequences of any previously analyzed accident. Furthermore, the opposite unft's EDGs will be maintained operable with the 2J EDG capable of being cross tied to the 1H Emergency Bus. Therefore, the request does not involve a significant increase in the probability or consequences of an accident or malfunction previously evaluated.
2.
Create the possibility of a ncw or different kind of accident from previously evaluated. The elecideal distribution system will continue to be operated in the same manner. No new failure scenarios, transient precursors, or limiting single failures are introduced. A loss of an emergency bus is assumed in the accident analysis. There are no adverse affects or challenges imposed on any safety system as result of the extended allowed time. Therefore, the possibility of a new or different kind of accident is not created by the one time extended allowed outage time for the 1H EDG.
3.
Involvo a significant reduction in the margin of safety. The opposite train of emergency power (1J emergency bus) and the associated engineered safety equipment remain operable to mitigate the consequences of any previously analyzed accident. Furthermore, the compensatory measures provide additional assurance that power will be available to power the 1H emergency bus in the event of an accident or transient. Therefore, the one time extended allowed outage time for the 1H EDG does not result in a significant reduction in the margin of safety.
ENVIRONMENTAL CONSEQUENCES The proposed enforcement discretion meets the 10 CFR 51.22(c)(9) eligibility criteria for categorical exclusion as specified below:
As specified above this request does not involve a significant hazards considerations.
The proposed enforcement discretion does not change the types of any effluents that may be released offsite, nor create a significant increase in individual or cumulative occupational radiatio. exposure. Operation of the plant is not beirg changed in any way to effect the amounts of effluents or create new types of effluents. The proposed enforcement discretion only extends existing action statement to affect repair of the 1H EDG. The redundant train of emergency power and train of safety equipment is adequate to mitigate the consequence of an accident. Th;s, the consequences of any analyzed accidents are not increased oy the extended alowed outage time of the 1H
- EDG,
The request does not adversely impact the operation of the reactor, and does not affect any system that would affect occupational radiation exposure. The proposed one-time extended allowed outage time for the 1H EDG does not create additional exposure to personnel nor affect the levels of radiation present in the plant.
Based on the above, it is' concluded that there will be no impact on the environment resulting from the proposed one time extended showed outage time for the 1H EDG, and that the request meets the criteria of 10 CFR 51.22 for categorical exclusion from the requiremonts of -10 CFR 51.21 relative to requiring a specific environmental assessment by the Commission.
CONCLUSION This enforcement discretion was reviewed and approved by the Station Nuclear Safety and Operating Committee, it has been determined that no unreviewed safety question or significant hazards consideration exists.
On October 28,1997, by telephone conference calls between our staffs, we requested enforcement discretion to extend the allowed outage time of Technical Specification 3.8.1.1.b from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to seven days. This enforcament 'tiscretion, if granted, will expire upon retuming the 1H EDG to operable status or at 20 'E hours on November 2, 1997, whichever is first.
Should you have any questions, please contact us.
Very truly yours, V4 James P. O'Hanlon Sonfor Vice President Nuclear cc:
U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington. DC. 20555 Mr. M. J. Morgan NRC Senior Resident inspector North Anna Power Station l
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