RBG-33774, Application to Amend License NPF-47,changing Tech Spec Table 3.8.4.1-1, Primary Containment Penetration Conductor Overcurrent Protection Devices, to Relocate Overcurrent Protection Breaker of RWCU Sys Precoat Pump
| ML20065G773 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 10/12/1990 |
| From: | Odell W GULF STATES UTILITIES CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20065G779 | List: |
| References | |
| RBG-33774, NUDOCS 9010230182 | |
| Download: ML20065G773 (8) | |
Text
{{#Wiki_filter:f. o GULF STATES O UTILITIES COMPANY miyta atesD 61 AfiON POST 08vitt DOE 720 61 i AAf40tSvtLLt, LouisiAn.A10776 AM A CODI MW $3f, (<*4 NE8061 October 12, 1990 RBG- 33774 File No. G9.5, G9.42 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555 . Gentlemen: River Bend Station - Unit 1 Docket No. 50-458 Gulf States Utilities (GSU) Company hereby files an application to amend the River Bend Station - Unit 1 Technical Specifications. Appendix A to Facility Operating License NPF-47, pursuant to 10CFR50.90. This application is filed to change Technical Specification Table 3.8.4.1-1, " Primary Containment i Penetration Conductor Overcurrent Protection. Devices," to relocate the overcurrent protection breaker for the reactor water cleanup system (RWCU) precoat pump. The Attachment to' this letter and Enclosure provide the justifications and proposed-revisions to the Technical Specifications. Your prompt attention to this application.is appreciated. ' Sincerely,
, ell Manager, Oversight River Bend Nuclear Group Attachment 9010230182 901012 PDR P ADOCK 05000458 PDC noot l{l
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a Ms. Claudia Abbate ; U. S. Nuclear Regulatory Comission : 11555 Rockville Pike . Rockville MD 20852 l NRC Resident Inspector - f,1 P.O. Box 1051 'i St. Francisville, LA 70775 :, Mr. G. A. Miller, Adminiitrator . j Radiation Protection Division Louisiana Department of' Environmental Quality : P. O. Box 14690 .. < ~? Baton Rouge, LA 70898 ,
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UNITED STATES OF AMERICA . NUCLEAR REGULATORY CONNISSION l j STATE OF LOUISIANA ) PARISH OF WEST FELICIANA ) Docket No. 50-458 In the Matter of ) GULF STATES UTILITIES COMPANY ) 5 (River Bend Station - Unit 1) AFFIDAVIT . W. H. Odell, being duly sworn, states that he is a Manager
- Oversight for Gulf States Utilities Company; that he is authorized on the part of said company to sign and file with ,
the Nuclear Regulatory Commission the documents attached hereto; and that all such documents are true and correct to I the best of his knowledge, information and belief.
<R 't ; 'i l W. H.'-Odell Subscribed and sworn to before me, a Notary Public in. and- .
for the State and Parish above named, this / S!I' -' day of OOdMMJL , 1990 . My Commission expires with Life, t hhA W L , NRih Claudia F. Hurst l Notary Public in and for . . . West Feliciana Parish, Louisiana
. l GRF STAITS tFf1LITIES GBE'ANY RIVER BERO S'IRTIOi DOCKET 50-458/LICEIGE NO. NPP-47 ElRCTRICAL B311198WP Pf0THCTIVE DEWIGS (90-19)
LICENSING DOCUMD7P INVOLVED: TD3INICAL SPICIFICATIONS ITIN: TABLE 3.8.4.1-1 PAGE: 3/4 6-29, 32 REASON FOR RD00EST: GSU requests a change to Specification 3.8.4.1 to relocate the Primary ; Containnent Overcurrent Protection breaker for the reactor water cleanup system (RWCU) precoat punp. This change is necessary to allow design inprovenents to be inplenented during the current refueling outage (RF) . The RWCU system is necessary for power operations and therefore GSU requests this change be approved prior to startup frun the current i refueling outage. The RWCU notor performs no safety related function and no safety related systczns, other than the containment penetrations, are affected by this nodification. he scheduled conpletion date for this outage is Novcsnber 25, 1990. DESCRIPTION: The RWCU systm is necessary for plant operation to rutove water inpurities in the reactor coolant pressure boundary and the loss of tle systm would' soon result in a plant shutdown as required by Specification'3.4.4. The system operation is described in Section 5.4.8 of the River Bend Station (RBS) USAR. During the last two operating cycles RBS has been experiencing poor RWCU dmineralizer perfornance. As a result of continuing -efforts to inprove the system operation a number of enhancenents have been identified. . One of the items is a nodification (MR) to increase the size of the RWCU precoat punp. This punp is not a safety related cmponent 1xit is located in the containnent. Therefore, the power supply containment penetration must be protected to ensure no loss of containnent integrity. GSU engineering. has been working expeditiously to cmpletc the MR to' support the current outage. As part of this review it was recently determined the MR will require a revision to the Prinary . Containment Penetration Conductor ' Overcurrent Protection Ikvices specification. The design is in accordance with all applicable technical specification bases and design criteria.
% ese. devices are identified in Specification 3.8.4.1 Table l' sections C.1 and C.4.
Containment electrical penetrations are part of the primary containment pressure boundary. As such, the short circuit power to the feed through conductors must be limited to prevent penetration seal degradation. he technical specifications require that circuits which run through these-penetrations have protective devices installed to prevent overcurrent conditions. Page 1 of 5 i r
l As described in the River Bend Station (RBS) Updated Safety Analysis Report (USAR) Section 8.3.1.1.4.3, containment electrical penetraticn assenblies are designed to withstand, without loss of nochanical integrity, the mxinun fault current versus tine condition which could occur because of single randan failure of circuit overload protective devices. No single failure causes excessive carmnt in penetration conductors which degrade penetration seals. All protective devices automatically disconnect power to the penetration conductors when currents through the conductors exceed the established protection limits. Electrical penetrations containing 480V power circuits are naminally rated to carry 180 percent of full load current continuously with all other circuits in the same penetration operating at full load. Overload pmtection of electrical penetration 480V notor control center power circuits is provided by a series connected nolded case circuit breaker and fuse , each rated to open the circuit during overload conditions, thus providing redundant protection. The circuit protection design provided for the increased capacity notor in this proposed change conforms to these requirenents. The requested change will remove load IG36-C002 from Section C.1 location:1NHS-MCC2E , cubicle:2B and add the load to Section C.4 location:1NHS-MCC2D , cubicle lE. Additionally, the design is similar to the as-built configurations for the remaining circuits listed on Technical Specification Table 3.8.4.1-1 Section C.5 which has a higher current cable design than C.4. The original design for River Bend's RWCU filter denineralizes included wedgewire type septa with a precoat pump naximum flow capacity of 200 GH. During cycle 2, gradual plugging of the wedgewire septa. occurred with frequent occurrence of resin breakthrough and poor demineralizer perfonw.nce. It was determined that replacenent of the wedgewire septa with porous notal septa should be perforned during RP2. Following instullation of the porous metal septa, poor danineralizer perfornance continued manifesting itself requiring frequent backwashes due to high differential pressure. An in depth study was performed to attempt to ascertain the root cause of these problans. Several design and unintenance issues were identified. The following design problems were identified as a result of this investigation:
- 1. Inadequate vent design which did not allow all of the air to vent past h the tubesheet.
- 2. Ibsign flowrate of 200 GM could not be obtained due to a plugged check valve.
- 3. Inadequate upward housing velocity to properly coat the porous netal septa also requiring a larger punp (350-400 GH vs. design 200 GH) .
Due to the above conditions, GSU determined that the pre-coat naterial had not been properly distributed on the porous netal septa. This condition resulted in poor danineralizer perfornance and the bare septa being exposed to reactor coolant which caused partial plugging of the media. The final configuration of the solutions were determined in late August 1990, with final design work proceeding at that tine. During the final design, it was discovered the increase in n cor size will require a significantly larger Page 2 of 5
( protection breaker (Gould type 80 , IVNR size 3) which could not be Installed in panel INHS-MDC2E due to physical size and electric load restrictions. This detennination was recently mde and efforts to accamodate the breaker in the sano panel location would require significant additional work and other license anendments. % erert.e, this request is the minimum necessary to ocatplete the MR. The IW2 problems are being addressed in the form of the following design nodifications: A design review was perfonted which determined that tne plugged check valve was not required. The internals to the valve were runoved thereby elindnating the problun with the valve sticking.
'Ihe existing porous netal septa, which are now at least partially fouled, are to be replaced during RP3 with new porous netal septa incorporating a new vent design.
The precoat flowrate will be increased during RF3 fran 260 GPM to 350-400 GPM by providing a larger pinp notor. (The flowrate was previously increased fran 200 GPM to 260 GIN by replacing the putp impeller. No further flowrate increase is possible without providing a larger pump notor. ) i The resulting benefit frun these nodifications are anticipated to be the following:
- 1. Increased run tine of the danineralizers resulting in lesser volunes of radwaste,
- 2. Fewer backwash cycles resulting in less operator exposure to perform the backwash,
- 3. Improved perfonunce of the danineralizer resulting in better reactor coolant chemistry and lower dose rates throughout the plant as a result,
- 4. Fewer backwash cycles resulting in less manipulation of autamtic valves and therefore, less maintenance of equipmnt resulting in less radwaste and lower mintenance exposure.
The MR initiated to increase the design flow capacity to 350-400 GPM will also aid in c: tending the life of the septa and therefore inprove RWCU effluent water quality to the reactor vessel. The notor for the precoat pinp (IG36-PC002) will be changed frcan the existing 10 HP,'1750 RPM notor to a 50 HP, 3500 RPM notor, this increase requires the power to be noved fran the present load center. Power to the new notor will be fran .{ INHS-MCC2D Cubicle lE. This is not a safety related power source since the ! pump is not required to perfonn any safety functions. However, the power - cable must pass through a containment penetration in order to get 'to the punp. As a result 'Ibchnical Specification Table 3.8.4.1-1 must be revised to include the above informtion. Because the MR will result in an enhancenent of reactor' water quality and_ _I' reduction of mintenance and radioactive waste GSU request this change be reviewed rapidly as possible to support startup from the current refueling outage. The present system outage schedule plans for installation of the Page 3 of 5 1 0
punp and related RWCU changes is to begin in late October. As additional infornation, the technical justification contained in this subnittal is very similar to that subnitted in support of Amendnent 40 to NPF-47 dated June 23 ,1989 (RBG-31140) . SIGNIFICANT HAZARDS CDNSIDEPATION: In accordance with requirennnts of 10CFR50.92, the following discussion is provided in support of the determination that No Significant Hazards are created or increased by the changes prop:) sed in this amendment request.
- 1. No significant increase in the probability or consequences of an accident previously evaluated results frcxn the proposed change because:
The equipnent involved in this request resides in the non-safety related, low pressum portion of the RWCU system and is located outside of the reactor coolant pmssure boundary. The precoat punp is only operated when each of the denineralizer/ filter trains am isolated and to be regenerated. The equipnent involved in this request is not involved in any analyzed accident nor called upon to mitigate the consequences of any event. 1 i
%e conduit, cable and equipnent associated with this nodification are being installed in accordance with all applicable seismic and electrical separation criteria. As such, adequate electrical i protection in confornance with the Technical Specification Bases and !'
USAR Section 8.3.1.1.4.3 is provided for all containment penetrations used. Operation or failure of the pump equipnent installed by this ! modification has no impact on any safety related system. Because this proposed change does not result in any new plant operating nodes and electrical penetration overcurrent protection is provided as described in the USAR, this proposed change cannot increase the probability or consequences of any accident previously evaluated.
- 2. We proposed change will not cruate the possibility of a new or i different kind of accident than any previously evaluated because: .!
A single failure of the equipnent installed by this nodification would at worst case be a loss of power to motor control center (MCC) 1NHS-M(r2E. Ioss of this non-safety related MCC is assumed by the USAR during design insis accident conditions and is therefore, as previously analyzed. No other new, credible failure nodes can be identified. The circuit protection design is similar to the rennining circuits identified in Section C.4 already listed on Technical Specification Table 3.8.4.1-1. Mditionally, this proposed change does not introduce any new plant operating nodes. Therefore, this proposed change can not create the possibility of a new or different kind of accident frun any previously evaluated.
- 3. The prvposed change does not involve a significant reduction in the !
nargin of safety because: { Overcurrent protection is provided such that no single failure will f caase excessive current in the penetration conductors. This ensures .J that the overcurrent protection is in accordance with the RBS USAR. "' Page 4 of 5
Additionally, the circuit protection design is similar to the rmaining circuits identified in section C.4 already listed on Technical Specification Table 3.8.4.1-1. The RWCU syste performs no safety related function and no safety related systms, other than the containment penetrations, are affected by this nodification. Further, the pmposed change does not result in any new plant operating nodes. Therefore, the proposed change does not result in any reduction in the norgin of safety. Based on the above considerations, the pmposed change does not increase the probability or the consequences of a previously evaluated accident, does not create the possibility of a new or different kind of accident fr m any previously evaluated, and does not involve a reduction in the margin of safety. Therefore, Gulf States Utilities Ompany proposes that no significant hazards are involved. . REVISED TECfNICAL SPECIFICATIONS: We requested revisions are provided in the Enclosure. SCHEDULE FOR ATI'AINING CDMPLIANCE: This change is being installed during the current refueling outage.
'Ibchnical Specifications 3.8.4.1 provides surveillances for properly designed circuits to ensure operability. With this assurance of operability, the Technical Specifications . allow the ' circuits to be energized in Operational (bnditions 1, 2, and 3. Since these circuits have not yet been added to the list of qualified overcurInnt protective devices, GSU will not be able to energize and operate this system during power operations. Because this system will be needed approxinately every 7 to.14 l days during operation this change will be necessary prior _ to startup frm this outage, currently scheduled for November 25, 1990.
N7I'IFICATION OF STATE PERSONNEL: , A copy of this amendment application has been provided to the State of ' ! louisiana, Department of Environmental Quality, Radiation Protection Division. ENVIRO?NENI'AL IMPACT APPRAISAL: Gulf States Utilities Company (GSU) has reviewed the proposed license ; amendment against the criteria of 10CFR51.22- for environmental considerations. As shown abave, the proposed changes do not involve a significant hazards consideration, nor increase the types and anounts of effluents that may be released offsite, nor significantly increase individual or cumulative occupational radiation exposures. Based on the foregoing, GSU concludes that the proposed changes meet the criteria given in 10CFR51.22(c) (9) for a categorical exclusion fran the requirment for an Environnental Impact Stateannt. Page 5 of 5 ?}}