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HomeMy WebLinkAbout851170.tiff °�0.R Whit UNITED STATES WELD f�'1NTY 41 ro f,,�r��d11CCj?lrrq ha - �'0 NUCLEAR REGULATORY COMMISSION �.�� . S REGION IV fly' Ir t i V I� jA iil • e Ill RYAN PLAZA DRIVE,SUITE 1000 I vLL 2 6 1985 1 t • ARLINGTON,TEAS 70011 LLL Ghi:LLgy, cocci. !Ai LJU Docket: 50-267 JUL 2 3 1985 Public Service Company of Colorado ATTN: 0. R. Lee, Vice President Electric Production P. 0. Box 840 Denver, Colorado 80201 Dear Mr. Lee: Based upon the information provided by members of your staff during telephone conferences on May 21 and 22, 1985, we have completed our review of Item 1.2 "Post Trip Review" contained in Generic Letter 83-28. We had provided our preliminary review finding by letter dated May 17, 1985; the telephone calls provided the needed clarification in some areas. The results of our review are contained in the enclosed Safety Evaluation. We have concluded that the post trip review data and information capabilities for the Fort St. Vrain Station are adequate and that Item 1.2 has been acceptably resolved. If you have any questions or comments on this matter, please contact us. Sincerely, .:, e. orwin R. Hunter, Chief Reactor Safety Branch Enclosure: Safety Evaluation of Item 1.2 cc: See next page 851170 1n A r Ai- 2 cc: Mr. D. W. Warembourg, Manager Nuclear Engineering Division Public Service Company of Colorado P. 0. Box 840 Denver, Colorado 80201 Mr. David Alberstein, 14/159A GA Technologies, Inc. P. 0. Box 85608 San Diego, California 92138 Kelley, Stansfield & O'Donnell Public Service Company Building 550 15th Street, Room 900 Denver, Colorado 80202 Chairman, Board of County Comm. of Weld County, Colorado Greeley, Colorado 80631 Regional Representative Radiation Programs Environmental Protection Agency 1860 Lincoln Street Denver, Colorado 80203 Mr. H. L. Brey, Manager Nuclear Licensing/Fuels Div. Public Service Company of Colorado P. 0. Box 840 Denver, Colorado 80201 J. W. Gahm, Manager, Nuclear Production Division Fort St. Vrain Nuclear Station 16805 WCR 19} Platteville, Colorado 80651 L. Singleton, Manager, Quality Assurance Division (same address) Colorado Radiation Control Program Director 0.0110E0u, • o UNITED STATES Fes. 2,; NUCLEAR REGULATORY COMMISSION �� , WASHINGTON,D.C.20555 e 0 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION PUBLIC SERVICE COMPANY OF COLORADO FORT ST. VRAIN UNIT 1 DOCKET NO. 50-267 GENERIC LETTER 83-28, ITEM 1.2 POST-TRIP REVIEW AND INFORMATION CAPABILITY) (DATA I, INTRODUCTION On February 25, 1983, both of the scram circuit breakers at Unit 1 of the Salem Nuclear Power Plant failed to open upon an automatic reactor trip plantlstart rectorion system. This tripped manuallyincident yb the nccurred peratorduring about the 30 seconds after the initiation of the automatic trip signal . The failure of the circuit breakers has been determined to be related to the sticking of the under voltage trip attachment. Prior to this incident, on February 22, 1983, at Unit 1 of the Salem Nuclear Power Plant, an automatic trip signal was generated based on steam generator low-low level during plant start-up. In this case, the reactor was tripped manually by the operator almost coincidentally with the automatic trip. Following these incidents, on February 28, 1983, the NRC Executive Director for Operations (EDO), directed the staff to investigate and report on the generic implications of these occurrences at Unit 1 of the Salem Nuclear Power Plant. The results of the staff's inquiry into the generic implications of the Salem unit incidents are reported in NUREG-1000, "Generic Implications of the ATWS Events at the Salem Nuclear Power Plant." As a result of this investigation, the Commission (NRC) requested (by Generic Letter 83-28 dated July 8, 1983) all licensees of operating reactors, applicants for an operating license, and holders of construction permits to respond to certain generic concerns. These concerns are categorized into four areas: (1) Post-Trip Review, (2) Equipment Classification and Vendor Interface, (3) Post-Maintenance Testing, and (4) Reactor Trip System Reliability Improvements. The first action item, Post-Trip Review, consists of Action Item 1.1, "Program Description and Procedure" and Action Item 1.2, "Data and Information Capability." This safety evaluation (SE) addresses Action Item 1.2 only. II. REVIEW GUIDELINES The following review guidelines were developed after initial evaluation of the various utility responses to Item 1.2 of Generic Letter 83-28 and incorporate the best features of these submittals. As such, these review guidelines in effect represent a "good practices" approach to post-trip review. The staff has reviewed the licensee's response to Item 1.2 against these guidelines: - 2 - A. The equipment that provides the digital sequence of events (SOE) record and the analog time history records of an unscheduled shutdown should provide a reliable source of the necessary information to be used in the post-trip review. Each plant variable which is necessary to determine the cause and progression of the events following a plant trip should be monitored by at least one recorder (such as a sequence-of-events recorder or a plant process computer) for digital parameters; and strip charts, a plant process computer or analog recorder for analog (time history) variables. Performance characteristics guidelines for SOE and time history recorders are as follows: ° Each sequence of events recorder should be capable of detecting and recording the sequence of events with a sufficient time discrimination capability to ensure that the time responses associated with each monitored safety-related system can be ascertained, and that a determination can be made as to whether the time response is within acceptable limits based on FSAR Chapter 15 Accident Analyses. The recommended guidelines for the SOE time discrimination is approximately 100 milliseconds. If current SOE recorders do not have this time discrimination capability, the licensee should show that the current time discrimination capability is sufficient for an adequate reconstruction of the course of the reactor trip and post-trip events. As a minimum, this should include the ability to adequately reconstruct the transient and accident scenarios presented in Chapter 15 of the plant FSAR. ° Each analog time history data recorder should have a sample interval small enough so that the incident can be accurately reconstructed following a reactor trip. As a minimum, the licensee should be able to reconstruct the course of the transient and accident sequences evaluated in the accident analysis of Chapter 15 of the plant FSAR. The recommended guideline for the sample interval is 10 seconds. If the time history equipment does not meet this guideline, the licensee should show that the time history capability is sufficient to accurately reconstruct the transient and accident sequences presented in Chapter 15 of the FSAR. To support the post-trip analysis of the cause of the trip and the proper functioning of involved safety related equipment, each analog time history data recorder should be capable of updating and retaining information from approximately 5 minutes prior to the trip until at least 10 minutes after the trip. ° All equipment used to record sequence of events and time history information should be powered from a reliable and non-interruptible power source. The power source used need not be safety related. - 3 - B. The sequence of events and time history recording equipment should monitor sufficient digital and analog parameters, respectively, to assure that the course of the reactor trip and post-trip events can be reconstructed. The parameters monitored should provide sufficient information to determine the root cause of the unscheduled shutdown, the progression of the reactor trip, and the response of the plant parameters and protection and safety systems to the unscheduled shutdowns. Specifically, all input parameters associated with reactor trips, safety injections and other safety-related systems as well as output parameters sufficient to record the proper functioning of these systems should be recorded for use in the post-trip review. The parameters deemed necessary, as a minimum, to perform a post-trip review that would determine if the plant remained within its safety limit design envelope are presented in Table 1 . They were selected on the basis of staff engineering judgment following a complete evaluation of utility submittals. If the licensee's SOE recorders and time history recorders do not monitor all of the parameters suggested in these tables, the licensee should show that the existing set of monitored parameters is sufficient to establish that the plant remained within the design envelope for the accident conditions analyzed in Chapter 15 of the plant FSAR. C. The information gathered by the sequence of events and time history recorders should be stored in a manner that will allow for data retrieval and analysis. The data may be retained in either hardcopy, (e.g. , computer printout, strip chart record) , or in an accessible memory (e.g. , magnetic disc or tape) . This information should be presented in a readable and meaningful format, taking into consideration good human factors practices such as those outlined in NUREG-0700. D. Retention of data from all unscheduled shutdowns provides a valuable reference source for the determination of the acceptability of the plant vital parameter and equipment response to subsequent unscheduled shutdowns. Information gathered during the post-trip review is to be retained for the life of the plant for post-trip review comparisons of subsequent events. III. EVALUATION AND CONCLUSION By letter dated November 4, 1983, Public Service Company of Colorado provided information regarding its post-trip review program data and information capabilities for Fort St. Vrain Unit 1. The staff has evaluated the licensee's submittal against the review guidelines described in Section II. Licensee deviations from the Guidelines of Section II were reviewed with the licensee by telephone on May 21 and 22, 1985. A brief description of the licensee's responses and the staff's evaluation of the response against each of the review guidelines is provided below: - 4 - A. The licensee's submittal described the performance characteristics of the equipment used to record the sequence of events and time history recorder data needed for post-trip review. Based on the staff's review, the staff finds that the sequence of events and time history recorder characteristics conform to the guidelines described in Section II A, and are acceptable. B. The licensee has established and identified the parameters to be monitored and recorded for post-trip review. The parameters identified in the submittal of November 4, 1983, as being recorded by the sequence of events and time history recorders, did not correspond to the parameters specified in Section II B of this report. The missing parameters were: (1) Reactor Building Temperature, (2) RSIV position, (3) Hot Reheat Steam Pressure, (4) Hot Reheat Steam Temperature, and (5) Hot Reheat Steam Activity. By telecon on May 21 and 22, 1985 Public Service Company of Colorado verified that these parameters are recorded and meet the criteria of Section II B in this report. Based on the staff's review, the staff finds that the parameters selected by the licensee include all of those identified in Table 1 and conform to the guidelines described in Section II B and are, therefore, acceptable. C. The licensee has described the means for storage and retrieval of the information gathered by the sequence of events and time history recorders, and for the presentation of this information for post-trip review and analysis. Based on the staff's review, the staff finds that this information will be presented in a readable and meaningful format, and that the storage, retrieval , and presentation conform to the guidelines of Section II C. D. The licensee's submittal indicates that the data and information used during post-trip reviews would be retained in an accessible manner for the life of the plant. Based on the staff's review, the staff finds that the licensee's program for data retention conforms to the guidelines of Section II D, and is acceptable. Based on this review, the staff concludes that the licensee's post-trip review data and information capabilities for Fort St. Vrain Unit 1 are acceptable. Principal Contributor: R. G. Ramirez, DHFS Date: June 27, 1985 _ 5 - TABLE 1 HTGR POST-TRIP REVIEW PARAMETER LIST SOE Time History Recorder Recorder (2) Parameter/Signal x Reactor Trip x Turbine Trip x Control Rod Position x (1) x Neutron Flux, Power x (1) x Reactor Building Temperature x Reactor Building Radiation x (1) x Primary System Pressure x Core Region Outlet Temperature x (1) x Circulator Inlet Temperature x (1) Circulator Speed x (1) Circulator Seal Malfunction x (1) Circulator Bearing Water Malfunction x (1) Circulator Drain Malfunction x (1) Circulator Penetration Overpressure x Primary System Flow x (1) x Primary System Moisture x MSIV Position x RSIV Position x (1) x Main Steam Pressure x (1) x Main Steam Temperature x (1) x Hot Reheat Steam Pressure x (1) x Hot Reheat Steam Temperature x (1) Hot Reheat Steam Activity x (1) Steam Generator Penetration Overpressure x Feedwater Flow x Steam Flow x Emergency Auxiliary Feedwater System; Flow, Valve Status _ 6 _ SOE Time History Recorder Recorder (2) Parameter/Signal X AC and DC System Status X Diesel Generator Status (1) Trip parameters (2) Parameter may be monitored by either an SOE or time history recorder MEQ(i O`'` 4? UNITED STATES •• NUCLEAR REGULATORY COMMISSION el! III n? "n .dn gp h n ; REGION IV (j,`"" ' �inn ,�jv rl�' ra °yam 4 b 817 RYAN PLAZA DRIVE,SUITE 1000 a -1 I , po ARLINGTON,TEXAS 70017 i JUL 26 ig85 JUL 23 1985 L�' JI Docket: 50-267 GREELEY. COLO. Public Service Company of Colorado ATTN: 0. R. Lee, Vice President Electric Production P. 0. Box 840 Denver, Colorado 80201 Dear Mr. Lee: We have reviewed the documents you have provided related to the construction of Building 10 and its associated walk-over structure. We find that additional information is needed for us to continue our review. Therefore, we request that you provide the information requested in the enclosure within 30 days of your receipt of this letter. If you have any questions on this request, please contact the NRC Project Manager, P. Wagner, at (817)860-8127. Since this reporting request relates solely to the Fort St. Vrain Station, OMB clearance is not required under P.L.96-511. Sincerely, 9orw40-n-P;-/E4 in R. Hunter, Chief Reactor Safety Branch Enclosure: Request for Information cc: See next page 2 cc: Mr. D. W. Warembourg, Manager Nuclear Engineering Division Public Service Company of Colorado P. 0. Box 840 Denver, Colorado 80201 Mr. David Alberstein, 14/159A GA Technologies, Inc. P. 0. Box 85608 San Diego, California 92138 Kelley, Stansfield & O'Donnell Public Service Company Building 550 15th Street, Room 900 Denver, Colorado 80202 Chairman, Board of County Comm. of Weld County, Colorado Greeley, Colorado 80631 Regional Representative Radiation Programs Environmental Protection Agency 1860 Lincoln Street Denver, Colorado 80203 Mr. H. L. Brey, Manager Nuclear Licensing/Fuels Div. Public Service Company of Colorado P. 0. Box 840 Denver, Colorado 80201 J. W. Gahm, Manager, Nuclear Production Division Fort St. Vrain Nuclear Station 16805 WCR 19# Platteville, Colorado 80651 L. Singleton, Manager, Quality Assurance Division (same address) Colorado Radiation Control Program Director REQUEST FOR ADDITIONAL INFORMATION FOR REVIEW OF BUILDING 10 AT FORT ST. VRAIN The following information is needed before an evaluation of Building 10 and the Walkover Structure can be completed: 1. Engineering drawings showing the Building 10 and Walkover Structure layout (plans and elevations) and its spatial relationship with the surrounding buildings. 2. A comprehensive list of the structural codes and revision dates including the section of the code used in the analysis. Several versions of the codes are referenced in the enclosure. Their specific use in the analysis should be clarified. 3. The attachment V referenced in the document CN 1460 page 89 was not included in the documents provided. 4. Provide the results of the seismic analysis including, but not limited to, the displacements of Building 10, the Walkover Structure and the surrounding structures. 5. Provide the effect of the tornado depressurization loads on the structure along with the effect of the tornado missile spectrum. 1,0 RFGu,_r UNITED STATES Lyt q tool rnvonot{f 7S G9. NUCLEAR REGULATORY COMMISSION i ( 1 c e. ; REGION IV —11 - - —< I i. ° ' g; Sit RYAN PLAZA DRIVE, SUITE 1000 t. �9 6 'I r'r� '� ARLINGTON,TEXAS 75011 � i JUL 2 3 1985 6REr LEY. COLD. In Reply Refer To: Docket: 50-267 Public Service Company of Colorado ATTN: 0. R. Lee, Vice President Electric Production P. 0. Box 840 Denver, Colorado 80201 Dear Mr. Lee: The Safety Evaluation enclosed in our July 12, 1985, letter contained some issues for which NRC review was not complete. We have now completed our review; the results are contained in the enclosed Supplemental Safety Evaluation. We have concluded that all of the open items related to our July 12, 1985, evaluation have been acceptably resolved. The commitments made by Public Service Company of Colorado, as discussed in the enclosure, are being included in the listing of commitments being confirmed in relation to the authorization of Fort St. Vrain restart. Sincerely, E. H. Johnson, Chief Reactor Project Branch Enclosure: Supplemental Safety Evaluation cc: Mr. D. W. Warembourg, Manager Nuclear Engineering Division Public Service Company of Colorado P. 0. Box 840 Denver, Colorado 80201 Mr. David Alberstein, 14/159A GA Technologies, Inc. P. 0. Box 85608 San Diego, California 92138 (cont. on next page) 7/N/sI Public Service Company of Colorado -2- Kelley, Stansfield & O'Donnell Public Service Company Building 550 15th Street, Room 900 Denver, Colorado 80202 Chairman, Board of County Comm. of Weld County, Colorado Greeley, Colorado 80631 Regional Representative Radiation Programs Environmental Protection Agency 1860 Lincoln Street Denver, Colorado 80203 Mr. H. L. Brey, Manager Nuclear Licensing/Fuels Div. Public Service Company of Colorado P. 0. Box 840 Denver, Colorado 80201 J. W. Gahm, Manager, Nuclear Production Division Fort St. Vrain Nuclear Station 16805 WCR 193 Platteville, Colorado 80651 L. Singleton, Manager, Quality Assurance Division (same address) Colorado Radiation Control Program Director SUPPLEMENTARY SAFETY EVALUATION BY THE NUCLEAR REGULATORY COMMISSION PUBLIC SERVICE COMPANY OF COLORADO FORT ST. VRAIN NUCLEAR GENERATING STATION DOCKET NO. 50-267 CONTROL ROD DRIVE AND POSITION INDICATION I. INTRODUCTION The NRC provided the results of the reviews of various Assessment Report issues in a Safety Evaluation (which included three additional evaluations as attachments) transmitted to Public Service Company of Colorado (PSC or the licensee) by letter dated July 12, 1985. Included in the issues discussed were control rod drive mechanisms (SE dated May 21, 1985) , and the CRDM instrumentation (SE dated May 17, 1985). There were areas of concern, in both of the above issues, for which our review was not completed at the time of issuance of the SE. These areas of concern have now been resolved. II. EVALUATION 1. Supplemental Evaluation of Control Rod Drive Mechanisms As discussed in our initial safety evaluation on the Control Rod Drive Mechanisms dated May 21, 1985, the staff required the following actions by the licensee in order to conclude that the CRDMs were acceptable for plant restart. These are: o The licensee must provide a commitment to operate the plant within the CRDM temperature limits accepted by the NRC. The temperature limits cannot be changed without NRC approval of new temperature limits or alternative methods of assuring CRDM operability; and o The licensee must provide a commitment to submit an improved CRDM surveillance and preventative maintenance program within 6 months of plant restart. By letters dated June 7, 1985 (P-85180) and July 3, 1985 (P-85233), the licensee submitted draft Technical Specifications for control rods. Technical Specification 3.1.1 in these submittals was a limiting condition for operation requiring that the CRDM motor temperature be less than or equal to 250°F. Additionally, Technical Specification 4.1.1 (P-85223) is a surveillance requirement for control rod operability. Section 4.1.1.A.1.a of this specification requires the licensee to record CRDM motor temperatures above 215°F and report the results to the NRC on a monthly (31 day) basis. -2- Additional clarification was provided in the resubmittal dated July 10, 1985 (P-85242) which specifies how the CRDM temperatures will be monitored. The licensee has committed (P-85180 and P-85242) to operate the facility in accordance with procedures based upon these draft interim Technical Specifications until formal Technical Specifications are approved and implemented. The operating procedures that implement these Specifications would be in place prior to plant restart. By letter dated June 14, 1985 (P-85199) , the licensee committed to submit an improved CRDM surveillance and preventative maintenance program within 6 months of plant restart. We find these commitments are acceptable to close the open issues from our previous evaluation, and that the CRDMs are acceptable for plant restart. 2. Supplemental Evaluation of Control Rod Instrumentation As discussed in our May 17, 1985 Safety Evaluation on Control Rod Position Instrumentation, all identified items were found to be acceptable with the exception of the following: o Confirmation of Cautions on Control Rod Overdrive o Additional Technical Specifications on Control Rod Position Instrumentation Operability o Additional Surveillance Tests on Control Rod Position Instrumentation o Initiation of the Reserve Shutdown System o Wattmeter Testing By letter dated July 10, 1985, the licensee provided interim Technical Specifications for Reactivity Control . The licensee committed to operate the plant under procedures based on these interim Technical Specifications until formal Technical Specifications are approved and implemented. By letter dated July 18, 1985, the licensee provided confirmation that all procedures involving possible control rod overdrive contained appropriate cautions and controls. We have evaluated the licensee's responses to the above items as follows: Confirmation of Cautions on Control Rod Overdrive In Section 3.2 of our May 17, 1985 evaluation, we found that the licensee has modified Procedure SOP 12-1 to preclude manual inward overtravel of rods following a reactor scram. It was not clear that this procedure covers all conditions in which manual inward motion of -3- a control rod could occur. By letter dated July 18, 1985, the licensee confirmed that all procedures in which rod travel beyond the full-in limit could occur contained appropriate cautions and controls to reduce the likelihood of damage to potentiometers and their couplings. Therefore, we find that the licensee has provided an acceptable response to this concern. Additional Technical Specifications on Control Rod Position Instrumentation Operability The licensee has proposed additional interim Technical Specifications to address the staff's concerns on operability of the Control Rod Position Instrumentation. Section 3.1.2 of these Technical Specifications is consistent with the Limiting Conditions for Operation described in Section 3.3 of our May 17, 1985 evaluation and are therefore acceptable. Additional Surveillance Tests on Control Rod Position Instrumentation The licensee has proposed additional surveillance requirements to address the staff's concerns on operability of the Control Rod Position Instrumentation. The combination of the licensee's proposed surveillance program and the additional surveillance stated in Section 3.4 of our May 17, 1985, evaluation combine to provide adequate assurance of RPI operability. The staff desired that the licensee: (1) verify each full-in limit indication prior to startup or during the first withdrawal of the rod from the full-in position; (2) verify the analog and digital position indications prior to startup or during the first withdrawal of the rod from the full-in position; and (3) verify reasonableness of the analog and digital control rod position indications. The proposed Technical Specifications (Section 4.1.2) are consistent with the desired concepts as described in Section 3.4 of our May 17, 1985, evaluation, and are therefore acceptable. However, we note that Section 3.4 of our evaluation acknowledges a quarterly surveillance of the rod-out limit indication, based on the licensee's proposal of January 31, 1985 (P-85040). The proposed Technical Specifications are silent concerning a periodic check of the out-limit indication. The out-limit indication operability should be verified on a periodic basis, and can be accomplished in conjunction with other tests (such as the partial scram test of fully withdrawn rods required by Technical Specification 4.1.1.B). Plant restart is acceptable without a specific surveillance requirement on out-limit indication. However, this surveillance should be explicitly incorporated in the final Technical Specification upgrade program. -4- Initiation of the Reserve Shutdown System The licensee has proposed additional Technical Specifications concerning initiation of the reserve shutdown system. As specified in Section 3.5 of our evaluation dated May 17, 1985, the licensee's backup shutdown procedure must be revised to assure adequate shutdown and certain verifications of rod positions shall be accomplished following each reactor scram. The proposed Technical Specifications (Section 4.1.6) provide consistent requirements for verification of rod position following a reactor scram, and are therefore acceptable. Section 3.1.6 of the proposed Technical Specifications requires insertion of reserve shutdown material if within 1-hour, more than two control rods are not verified to be fully inserted. The staff requirement was to insert reserve shutdown material if more than one control rod cannot be verified to be fully inserted. The analysis of Section 3.5.3.1 of the Updated Final Safety Analysis Report demonstrates that adequate shutdown margin exists with two rods withdrawn and that the requirements of Technical Specification 3.1.4 (Shutdown Margin) can be met. Consequently, proposed Technical Specification 3.1.6 is acceptable. Wattmeter Testing In Section 3.6 of the May 17, 1985 evaluation, the staff concluded that the wattmeter test proposed by the licensee is an adequate method of verifying the rod full-in position provided that the ease of interpretation of the data is increased and the level of reliance on judgment and interpolation is decreased through the use of a more appropriate choice of wattmeter range and recorder speed. Although the staff expresses some concern over the licensee's method and procedures, this item requires no further action prior to facility restart. However, the licensee should confirm that they have addressed this recommendation as a long term item. III. CONCLUSION The staff has reviewed the interim Technical Specifications submitted by the licensee by letter dated July 10, 1985 (P-85242) , and the additional confirmation concerning control rod overdrive procedures submitted by letter dated July 18, 1985, and finds that these submittals address the concerns in the staff's SE dated July 12, 1985. We conclude that the control rod drive mechanisms and associated position instrumentation is acceptable for plant restart and continued operation. -5- The staff has identified two items which should be pursued as long-term improvements in Technical Specifications and Plant procedures. These items are a specific surveillance test for the control rod out-limit indication and improvements to the wattmeter tests. Date: July 19, 1985 Principal Contributor: K. Heitner RFGU UNITED STATES ``EpP 4 a NUCLEAR REGULATORY COMMISSION a▪ t I� ° REGION IV N ° y 611 RYAN PLAZA DRIVE,SUITE 1000 r,• •o e`^"`` No ARLINGTON,TEXAS 75011 WELD COUNTY COMMISSIONERS JUL 19 1985 _ Docket: 50-267 JUL 2 41985 Mr. 0. R. Lee, Vice President Electric Production Public Service Company of Colorado P.O. Box 840 Denver, Colorado 80201 Dear Mr. Lee: We have reviewed the various submittals you have made in response to our October 16, 1984, "Preliminary Report Related to the Restart and Continued Operation of the Fort St. Vrain Nuclear Generating Station," and other submittals related to subjects which have required resolution prior to the resumption of operations at Ft. St. Vrain (FSV). We have provided the results of our reviews of the various areas of concern in a number of recently issued Safety Evaluations (SEs). These safety evaluations contain the NRC findings on all issues associated with the above report. In addition, we have approved some of your proposals for resolving some of our concerns which will require long-term actions. A listing of our SEs and approvals is contained in Enclosure 1, a listing of your various commitments is contained in Enclosure 2. Our June 26, 1984, confirmatory action letter (CAL) confirmed your commitment that FSV would be maintained in a shutdown condition until the NRC authorized a different status. Our reviews have now progressed to such a point that we have determined that you have satisfied the commitments contained in our June 26, 1984, letter and have addressed the issues raised in the October 16, 1984, report. We find it acceptable, therefore, for FSV to be operated in a "dry-out" mode to aid in the removal of moisture. Such an operation would hold reactor power below a level at which boilout in the economizer-evaporator- superheater section of the steam generator would be achieved, but in no case greater than 15% Rated Thermal Power until such time as certain equipment qualification questions are resolved. Our evaluation of the acceptability of operating FSV in this mode is contained in the enclosed Safety Evaluation (Enclosure 3). In addition, we have reviewed your proposed compensatory measures in the area of fire protection, contained in your letter dated July 11, 1985, (P-85245) and find them to be an acceptable basis to allow interim operations until our technical review is completed. We have confirmed your commitments in the listing contained in Enclosure 2; a SE of our finding will be provided under separate cover. In authorizing the restart and the operation of Fort St. Vrain at power levels not to exceed 15% power, we understand that you have committed to the following actions: .,,,TG -11 /8S Public Service Company of Colorado -2- 1. Unless authorized by NRC to proceed to a higher power level , PSC will restrict plant power level to no greater than 15% power. PSC shall notify the NRC of the completion of aging and equipment operability studies for equipment qualification under 10 CFR 50.49. 2. PSC will continue to implement those items listed as complete and will resolve the longer range issues contained in Enclosure 2. In doing so, the scope and schedule for resolution of these issues, that has been previously agreed to with the NRC staff, shall not be altered without prior agreement of the NRC staff. If your understanding of these commitments is not the same as ours, please contact our office within 24 hours at (817) 860-8100. Since these reporting requirements relate solely to the FSV, OMB clearance is not required under P.L. 96-511. Sincerely, /,o ei 7` / il) 7 Robert D. Martin Regional Administrator Enclosures: 1. List of SEs and Approvals 2. List of PSC Commitments 3. SE Related to Environmental Qualifications cc: Mr. D. W. Warembourg, Manager Nuclear Engineering Division Public Service Company of Colorado P. 0. Box 840 Denver, Colorado 80201 Mr. David Alberstein, 14/159A GA Technologies, Inc. P. 0. Box 85608 San Diego, California 92138 (cont. on next page) Public Service Company of Colorado -3- Kelley, Stansfield & O'Donnell Public Service Company Building 550 15th Street, Room 900 Denver, Colorado 80202 Chairman, Board of County Comm. of Weld County, Colorado Greeley, Colorado 80631 Regional Representative Radiation Programs Environmental Protection Agency 1860 Lincoln Street Denver, Colorado 80203 Mr. H. L. Brey, Manager Nuclear Licensing/Fuels Div. Public Service Company of Colorado P. 0. Box 840 Denver, Colorado 80201 J. W. Gahm, Manager, Nuclear Production Division Fort St. Vrain Nuclear Station 16805 WCR 19} Platteville, Colorado 80651 L. Singleton, Manager, Quality Assurance Division (same address) Colorado Radiation Control Program Director Enclosure 1 LIST OF SAFETY EVALUATION/APPROVALS ISSUED RELATED TO THE RESTART OF FORT ST. VRAIN Date Subject July 8, 1985 Prestressed Concrete Reactor Vessel Tendon Wire Corrosion Problem SE July 9, 1985 Liquid Effluent Release from the Reactor Building Sump. July 10, 1985 Emergency Electrical Power Systems SE July 12, 1985 Assessment Report SE (CROM, Technical Specifications, and Management Controls) July 12, 1985 CRDM Bearing SE letter W O) C O) I C In 0 IC V•r ++ C 4- L ..--. r 44-1 W 0 r 7 W N 00 .) CO co 4O-1 O IF 9C1 -I O C Ian E E E In � E E c W- L W W . C W W W W WV 66 7 r 4-1 4.) 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VRAIN NUCLEAR GENERATING STATION DOCKET NO. 50-267 ENVIRONMENTAL QUALIFICATION OF ELECTRIC EQUIPMENT IMPORTANT TO SAFETY Background As part of the ongoing review of licensees' conformance to the requirements for environmental qualification, the staff raised a number of issues concerning the adequacy of the Fort St. Vrain program. By letter dated January 28, 1985, Public Service Company of Colorado (PSC) was requested to provide additional information in order to determine the extent of compliance with the requirements of 10 CFR 50.49, the rule on environmental qualification of electric equipment important to safety. PSC provided a response to that request in a letter dated March 28, 1985. Additional information on environmental qualification was provided by the licensee in a letter dated March 25, 1985 in response to Generic Letter 84-24, Certification of Compliance to 10 CFR 50.49. A meeting with the licensee to discuss the status of the Fort St. Vrain equipment qualification was held in Bethesda, Maryland on April 3, 1985. As a result of the information provided at this meeting and the licensee's letter further clarifying information was requested by the staff in a letter dated May 7, 1985. The response to that request is a letter from PSC dated June 11, 1985. On July 2, 1985 staff members from NRR and Region IV again met with the licensee to discuss the current status of the Fort St. Vrain equipment qualification program. A letter dated July 11, 1985 was sent by PSC to address followup issues. Staff Evaluation A summary of the results of the staff review and evaluation of the information provided follows. 10 CFR 50.49 requires each holder of an operating license to establish a program for qualifying electric equipment important to safety. The program must include and be based on the time-dependent temperature and pressure conditions at the location of the equipment resulting from the most severe design basis accident during or following which the equipment is required to remain operable. The program must also include and consider, if applicable, the effects of humidity, chemical spray, radiation, aging, submergence, and synergism. - 2 - In accordance with 10 CFR 50.49, equipment for Fort St. Vrain may be qualified to the criteria specified in either the DOR Guidelines or NUREG-0588, except for replacement equipment. Replacement equipment installed subsequent to February 22, 1983 must be qualified in accordance with the provisions of 10 CFR 50.49, using the guidance of Regulatory Guide 1.89, unless there are sound reasons to the contrary. The rule requires that operating reactors achieve environmental qualification of all equipment by no later than March 31, 1985 unless an extension is granted by the Director of the Office of Nuclear Reactor Regulation. A record of qualification, including all necessary documentation, must be maintained in an auditable form for the period of time the covered item is installed or stored for future use. The licensee's March 25, 1985 response to Generic Letter 84-24 concludes that all equipment which is required to be qualified has been qualified and that Fort St. Vrain is in full compliance with 10 CFR 50.49. This position was reiterated in the letter of June 11, 1985. However, the staff review of the information provided by the licensee in support of this claim leads to the following observations: 1. The Fort St. Vrain equipment qualification program is based on the environmental conditions which result from an assumption that a main steam line break can be isolated within 4 minutes. If isolation cannot be accomplished within 4 minutes, the temperature continues to increase and could invalidate any claim of environmental qualification. The adequacy of this assumption is under review by the staff and the results could have an impact on the equipment qualification program. 2. For each equipment item, age-related degradation which could prevent operation of the equipment must be identified and the equipment replaced or repaired as necessary. The qualified life of the equipment cannot be exceeded before corrective action is taken. The licensee has stated that aging effects are not presently included in the qualification program but an effort in this area has begun. One necessary element which will establish the validity of the Fort St. Vrain qualification program is that the results of the aging analysis must be used to determine that equipment is currently qualified, and must be factored into the surveillance/replacement intervals to assure that equipment is maintained in a qualified state. Corrective action must be taken before, not after, the equipment has exceeded its qualified life. 3. Operability times have not been established for specific pieces of equipment in compliance with the requirement in 10 CFR 50.49 to demonstrate the capability to perform the required function for the time the equipment is required to remain operable. The licensee has committed to perform a study to establish operability time requirements. Qualification cannot be considered demonstrated until the licensee determines that the equipment can perform its intended function for the period of time it is required to operate during and following an accident. - 3 - 4. The licensee has identified a number of outstanding items to be completed as part of the qualification program and has provided a schedule for resolution of these items. The scheduled completion dates for these items extend to March 1986 and are inconsistent with the schedule requirements in 10 CFR 50.49. Conclusion As summarized above, a number of deficiencies are evident in the qualification program and in the information provided to the NRC for review. Also, guidance regarding the content and auditability of environmental qualification files was provided to licensees and applicants in IE Information Notice 85-39, dated May 22, 1985. Based on the information provided by PSC, it is clear that documented evidence of qualification does not now exist for equipment in Fort St. Vrain. Therefore, contrary to the assertions made by the licensee, the NRC staff cannot at this time conclude that conformance to the requirements of 10 CFR 50.49 has been demonstrated for Fort St. Vrain. As a result of the discussions during the July 2, 1985 meeting and the licensee letter of July 11, 1985, the staff decided that the facility should not be allowed to go to full power operation until all environmental qualification issues are resolved to the extent that conformance with 10 CFR 50.49 can be demonstrated. The licensee is actively pursuing the means to resolve these issues. For the interim period, the licensee has proposed a hold on reactor power to levels less than 15% of rated power to allow initiation of moisture dryout in the reactor vessel stating that the lower energy release rates at these power levels result in significantly lower peak equipment temperatures. The staff has reviewed the information provided by the licensee in support of the proposed low power operation. Based on the results of that review, we find that operation pending resolution of these issues is allowable. The staff agrees that operation of the plant at power levels not exceeding 15% will preclude any significant effects on the equipment in question should an accident occur and that such interim operation will not adversely affect the health and safety of the public. Date: July 19, 1985 Principal Contributor: A. Masciantonio, DE Hello