ML19354D699
| ML19354D699 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 12/21/1989 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 89-854, GL-89-04, GL-89-4, NUDOCS 8912290123 | |
| Download: ML19354D699 (6) | |
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VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 December 21, 1989 U.S. Nuclear Regulatory Commission Serial No.89-854 Attention: Document Control Desk NO/DEO:deq R9 Washington, D.C. 20555 Docket Nos.
50 338 50 339 License Nos. NPF 4 NPF 7 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA PQWER STATION UNITS 1 AND 2 CONTROL ROOM HABITABILITY SYSTEM. INSTRUMENT AIR SYSTEM, " MIDAS" SOFTWARE AND HARDWARE.
AND INSERVICE TESTING FLOW INSTRUMENTATION REVISED COMMITMENTS REGARDING DESIGN MODIFICATIONS During the course of the year, Virginia Electric an'J Power Company has committed to complete several plant modifications at North Anna Power Station by the end of 1989, Hcwever, certain of these modifications will not be fully implemented by December 31, 1989.
These modifications involve upgrades to the Instrument Air System, er,hancements to the Control Room Habitability System, installation of Inservice Testing flow Instrumentation, and installation of the Metocrological Information and Dose Assecsment System (MIDAS) to rep; ace the RAD / MET computer mode', The fr, tent o; thir letter is to identify the modifictions unable to be completed by the end of the year end provide status and implementation schedules concerning each of those l
mooltications.
MS.likme"+t AirJ2yn2idrbigngqs An Enforcement Cer,terence was held in the NRO F.ogion it officos on February 7, j'
1989 to discuse NRC concems mgardirig lastrument' air problems at North Anna l
Power Station. During the meeting, Virginia Electric and Power Company made l
commitments to install two additional instrument air compressors and two additional air dryers in the Auxiliary Building by the end of 1989. Also during this meeting, commitments were made to complete several subsequent to modification activities associated with the instrument air system by the end of the year (i.e., UFSAR changes, personnel training, design basis documentation reviews, and procedure revisions).
The NRC concerns for the air quality In the instrument air system were emphasized in a Notice of Violation with an imposed civil penalty dated April 21,1989. Our response to the Notice of Violation, letter dated May 22,1989 (Serial No. 89 321), restated that the long term upgrades to the instrument air system were scheduled to be completed by the end of 1989 based on our current engineering, procurement, and installation AW 22gggf ggj g
schedules. However, we are unable to complete these instrument air system upgrade modifications by the end of the year.
During the February 7,1989 meeting, we had also committed to 1) install a coalescing filter in the Turbine Building on the inlet line of the instrument air dryer from the diesel driven air compressor by the end of February 1989 and 2) install additional oil filters on the lines that supply service air to the service air receivers by the end of 1989. The modification to install the coalescing filter on the inlet line of the instrument air dryer has been completed. Administrative controls have been put in place to restrict the use of construction air as a backup to instrument air, Consequently, the need for the additional oil filters on the supply service air lines to the service air receivers has been eliminated.
Since the February 7,1989 meeting, increased management attention has been focused on the instrument air system. Both the instrument air and service air systems have been reviewed with the intent of improving system operation and reliability.
Subsequently, we have revised the scope of our instrument air and service air systems upgrade modifications. For the instrument air system, the review determined the need for better air quality and recommended the addition of new oll free air compressors, new desiccant air dryers, and coalescing / particulate filters. For the service air system, this review determined the need for new oil free air compressors, new desiccant air dryers, and replacement of the service air header to the Auxiliary Building with upgraded material and improved routing to eliminate existing moisture traps.
To date the following upgrades have teen completed. To ensure the quality of instrument air is maintained, a preventative maintenance program for instrument si' system components has been implemented. A backup diesel-driven, oil free air compressor has been insta; led, and maintained on standby, to supply quality i
iristrument air it meauy. A twin tower desiccant dryor with inlet and outiv. idters for oli and carticulate removai were installed on the insttument air system in the Turbine Building. During the refueling outago, new motors were installed on the Sull alt compressors, the instrument air headers were blown dcwn, and over 100 components were inspected and cleaned as necessary. An -electric, cil free compressor har., Liso been installed to provide quality instrument air. Installation and operation of this electric cornpressor has ensbied us to place the Sullair ccmpressors on star. cay.
Design Change Packages are being developed te c! rect the insta' latten activatios fut the modifications to the instrument air system in the Auxiliary Building comrnitted to in the February 7,1989 meeting. However, due to the additional enginaaring and procurement activities discussed above, installation of the two additional enhanced instrument air compressors and two additional air dryers will not be complete by the end of the year. Based on the latest engineering and procurement status, completion of the instrument air system modifications (in the Auxiliary Building) are anticipated on the following schedule:
IA Dryers, Two Installed and in operation.................................... February,1990 IA Compressor, First installed and in operation.......................... March,1990
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IA Compressor, Second installed and in operation................... June,1990
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Two new service air compressors will also be installed after the instrument air compressors are in operation. The installation of these four new compressors (two instrument air and two service alr) will eliminate the need for the backup diesel-driven compressor, the electric compressor, and the Sullair compressors currently staged outside the Turbine Building.
To provide increased reliability of the instrument air system and provide quality instrument air, one of the Sullair compressors will be replaced with a temporary additional electric oil free compressor. This additional electric oil free compressor will be maintained on standby as a backup to the currently installed electric oil free compressor discussed above.
Control Room Habitability System Enhancements An Enforcement Conference was held in the NRC Region 11 offices on January 18, 1989 to discuss control room habitability concerns at North Anna Power Station.
During the January 18,1989 meeting, Virginia Electric and Power Company made commitments to provide 1) auto start of the emergency control room ventilation fans in recirculation mode upon receipt of a bottled air system actuation signal and 2) auto-Isolation of the normal control room air supply and exhaust upon receipt of a fuel building high high radiation alarm. These modifications were intended to ensure long-term compliance with General Design Criteria (GDC) 19 of Appendix A to 10 CFR 50.
These modifications were to be completed by December 31,1989.
As discussed in our letter dated March 1,1989 (Serial No. 89 022), a GDC 19 reanalysis wac performed by engineering to allow multiplo control room entries in the event of an accicerit. The engineering evaluation reviewed various design basis accidents with relation to radia'.lon exposure to tha control toom operator. As a result of this evaluation, the following administrative controls were implernented for the control room habitability system: 1) the control room emergency ventilation syctem is to
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be aligned in the recirculation mode during normal power operation,2) the Emergency Operating Procedures were revised to ensure initiation of the emergency ventilation system with filtered recirculation within 10 minutes of the inithtbn ci a Safety injection s'cnal,3) the Operating Procedures were revlaco to rooulto manual! solation of the r ormal supply and exhaust far the control room during fuel movement in the fuel building, and 4) the Abnormal Operating Procedures were revicea to require manual initiation of the bottled elr system upon receipt of a high high radiation signalin the fuel building. With these administrative contruts in place, North Anna is currently operating in compliance with GDC 19 and would be allowed multiple control room entries in the event of an accident.
As stated in our March 1,1989 letter, further review performed by engineering focused on relieving the control room operators from having to perform emergency ventilation system lineups manually. Based on the results of the review, it was determined that initiation of bottled air upon receipt of a high high radiation signalin the fuel building and isolation of the control room upon discharge of the bottled air system should be an automatic system response, it was our Intent to implement the modifications to provide I
this automatic system response on the end of the year schedule discussed in the January 18,1989.
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A Design Change Package is being developed to provide for 1) the automatic initiation of bottled air and isolation of the control room normal air supply and exhaust upon receipt of a high high radiation signal in either the fuel storage or fuel bridge area of the fuel building and 2) auto start of the emergency control room ventilation fans in recirculation mode upon receipt of a bottled air system actuation signal. However, during the design development process, additional requirements were identified which have resulted in longer material delivery and construction durations than were originally estimated. The revised design specifies a new seismically qualified relay control panel and additional seismically supported conduit be installed. Because of the lor,g lead time required for procurement of this se'omir. equipment, the project will not be completed by the end of 1989.
Bar.,d on the latest engineering and procurement status, it is now anticipated th t Inis design change will be complete in June,1990.
Inservice Testina Flow Instrumentation Installation in our response to NRC Generic Letter 89 04,
- Guidance on Developing Acceptable Inservice Testing Programs," letter dated October 3,1989, we committed to evaluate the use of strap-on flow instrumentation to measure flow from the boric acid transfer pumps as enhanced assurance of the equipments' operability, if these strap on flow instruments were found capable of providing stable and accurate test results, they were to be in place and available for Section XI pump operability readiness testing by December 31, 1989.
We also committed to the installation of strap on flow instrumentation for verification of full design flow capability through the charging pump discharge recirculation line check valves. These strap on flow instruments were to be installed by December 31,1989.
i Engineering Work Requests (EWRs) have been submitted for instal!ation of the strap-on flow instrJm90ts. However, because it has not yet been determined whether the strap on instruments can provide stable and accurate test results on these piping systems, the EWRs are on hold. Additionally, procurement of the required portable flow instrument computer has been dolayed.
We currently plan to procure the f:ow instruoent computer ard ons Get of transduccrs and one strap-on holder / collar. This unit wil! ba used to e6tablish 1) whether stable and accurate test results are achievable with this technology on the subject piping and
- 2) the best location for installation of the strap on holder / collar and transducers. The results of this evaluation will determine whether to procure and install additional strap-on holder / collars and transducers or cancel the EWRs and procure more permanent type flow instrumentation for installation during the next refueling outages.
l Temporary test procedures for performance of the above capability evaluation have been developed and are ready for approval as soon as the test equipment is available, it is estimated that procurement of the required equipment, performance of the capability evaluation, and the determination whether to procurs and install additional strap on holder / collars and transducers can be completed in March,1990.
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- MIDAS' Comnuter System inntattation NRC Inspection Report 50 338,339/89 02 identified findings resulting from the Emergency Response Facility (ERF) Appraisal conducted at North Anna Power Station. In our April 24,1989 response to the ERF appraisal findings, we committed to perform several near term evaluations and implement the appropriate solutions.
Pursuant to our evaluations, we have resoived differences between certain aspects the existing Radiological / Meteorological (RAD / MET) computerized dose assessment model and the manual dose assessment Emergency Plan Implementing Procedures (EPIPs). These near term activities have been completed. The corrective actions for the appraisalitems were reviewed during the August 8,1989 Emergency Exercise as documented in NRC Inspection Report No. 89 25, dated October 6,1989.
Additionally, in our April 24,1989 response letter, we stated our intention to procure and install the Meteorological Information and Dose Assessment System (MIDAS) methodology (software and hardware) to replace the existing Radiological / Meteorological (RAD / MET) computerized model. The use of MIDAS methodology is considered an enhancement to our overall dose assessment program.
The procurement of MIDAS software and hardware, development of compatible dose assessment procedures, and the training for emergency response personnel were projected to be complete by the end of 1989.
On September 5,1989, Messrs J. P. O'Hanlon, R. J. Hardwick, and J. E. Collins met with NRC personnelin the NRC Region ll offices in Atlanta to discuss enhancements to the Virginia Power Emorgency Preparedness Program. During the meeting, we ident!fied our intended approach and schedule for implementation of the program enhancemente.
included was a discussion about installation of MIDAS which identified that procurement of the MIDAS system along with procedure development and training would require mere time than ori loally anticipated, it was indicated that 0
implementatiori of MIDAS methodology may be delayed.
The Design Change Package for installation of the MIDAS system has been developed and approved and the computer system to be used for MIDAS i
methoriology is presently at the vendor's facilities awaiting factory acceptance testing.
It !s currently anticipated that the hardware modifications will be complete softvvare installed, EPIPs developed, and personnel trained in July,1990.
If you have any questions or require additionalinformation, please contact us.
Very truly yours, al W. L. Stewart Senior Vice President Nuclear 5
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U.S. Nuclear Regulatory Commission Region il l
101 Marietta Street, N.W.
Suite 2900 Atlanta, Georgia 30323 Mr. J. L. Caldwell 1
NRC Senior Resident inspector North Anna Power Station i
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