ML15112A988
| ML15112A988 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 01/28/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML15112A987 | List: |
| References | |
| NUDOCS 8102200793 | |
| Download: ML15112A988 (5) | |
Text
'0 tGUNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, 0. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 92 TO FACILITY OPERATING LICENSE NO. DPR-38 AMENDMENT NO.92 TO FACILITY OPERATING LICENSE NO. DPR-47 AMENDMENT NO.89 TO FACILITY OPERATING LICENSE NO. DPR-55 OCONEE NUCLEAR STATION, UNITS NOS.
1, 2 AND 3 DUKE POWER COMPANY DOCKETS NOS. 50-269, 50-270 AND 50-287 I.
INTRODUCTION This Safety Evaluation deals with three separate license amendment requests.
Duke Power Company (DPC or the licensee) in each request proposed changes to the Technical Specifications (TSs) appended to Facility Operating License Nos. DPR-38, DPR-47 and DPR-55 for the Oconee Nuclear Station (ONS) Units Nos. 1, 2 and 3. The request dated October 2, 1980, also proposed three additional license conditions.
- a. By letter dated May.21, 1979, the licensee requested revisions to the high pressure reactor trip setpointtand thepressurizer power operated relief valve (PORV) setpoint.
- b. By letter dated October 2, 1980, as supplemented October 30, 1980, the licensee requested the incorporation of certain of the TMI-2 Lessons Learned Category "A" requirements into the ONS license and TSs.
- c.
By letter dated October 20, 1980, the licensee requested the inclusion of an additional section of Regulatory Guide 1.16 concerning reporting requirements into the TSs.
II.
BACKGROUND INFORMATION The following discussion concerns the October 2, 1980 request only. The backgrounds of the May 21, 1979 and October 20, 1980 requests are provided in conjunction with the Evaluation sections. By our letter dated September 13, 1979, we issued to all operating nuclear power plants requirements es tablished as a result of our review.of the TMI-2 accident.
Certain of these requirements, designated Lessons Learned Category "A" requirements, were to have been completed by the licensee prior to any operation subsequent to January 1, 1980.
Our evaluation of the licensee's compliance with these Category "A" items was attached to our letter to the licensee dated April 7, 1980.
In order to provide reasonable assurance that operating reactor facilities are maintained within the limits determined acceptable following the imple mentation of the TMI-2 Lessons Learned Category "A" items, we requested 8102 20
-2 that licensees amend their TSs to incorporate additional Limiting Conditions of Operation and Surveillance Requirements, as appropriate. This request was.transmitted to all licensees on July 2, 1980.
Included therein were model specifications that we had determined to be acceptable. The licensee's application is in direct response to our request. Each of the issues iden tified by the NRC staff and the licensee s response is discusstd in the Evaluation below.
III.
EVALUATION
- a. High Pressure Reactor Trip and PORV Setpoints In response to IE Bulletin 79-05B, the licensee submitted by letter dated May 21, 1979, a proposed amendment to the TSs lowering the setpoint of the high pressure reactor trips from 2355 psig to 2300 psig. Concurrently, the licensee proposed raising the setpoint of the pressurizer electromatic relief valves, also known as the power operated relief valves (PORV),
from 2255 psig to 2450 psig. The licensee physically changed the setpoints prior to the TS change request, as part of his response to IE Bulletin 79-05B. The lowered high pressure trip setpoint was within the envelope of the existing TS, thus the licensee did not need this change to be issued to lower the setpoint. The PORV setpoint is not subject to TS limitations; however, the PORV setpoint is identified in the basis of TS Section 2.2 -
Safety Limits Reactor Coolant System Pressure.
In the past, during turbine trip and loss of feedwater transients, the PORV was lifted and the reactor would not trip unless the pressure setpoint was exceeded. With the new setpoints, these transients do not result in lifting of this valve. Therefore, this valve does not open as frequently and the likelihood of the valve failing to close, i.e., producing a small break lss of coolant event, is reduced. However,.the likelihood of a reactor trip is increased. We do not consider this increase in frequency of a reactor trip to be significant over the lifetime of the plant. The PORV function is to control an operational transient and not to protect the reactor coolant system pressure boundry. The safety valves provide thi.s function. The new set points would not reduce the margin.of safety or increase the probability or consequences of accidents. We find the proposed changes to the TSs acceptable.
- b. TMI-2 Lessons Learned Category "A" Requirements Emergency Power Supply Requirements The pressurizer water level indicators, pressurizer relief and block valves, and pressurizer heaters are important in a post-accident situation. Adequate emergency power supplies add assurance of post-accident functioning of these components. The licensee has the rqquisite emergency power supplies.
The licensee has proposed adequate TSs which provide.for a 31-day channel check and an annual channel calibration and actions in the event of component inoperability. We have reviewed these proposed TSs and find that the emergency power supplies are reasonably ensured for post-accident functioning of the subject components and are thus acceptable.
-3 Direct Indication 6f Valve Position The licensee has provided a direct indication of PORV and safety valve position in the control room. These indications are a diagnostic aid for the plant operator and -provide no automatic action. The licensee has provided TSs with a 31-day channel check and an annual channel.calibration requirement; thus, the TSs are acceptable and they meet our July 2, 1980 model TS criteria.
Instrumentation for Inadequate Core Cooling The licensee has installed an instrument system to detect the effects of low reactor coolant level and inadequate core cooling. These instruments, sub cooling meters, receive and process data from existing plant instrumentation.
We previously reviewed this system in our Safety Evaluation dated April 7, 1980.
The licensee submitted TSs with a 31-day channel check for the input components of these instruments and an 18-month channel calibration requirement and actions to be taken in the event of compoient inoperability. We conclude the TSs are acceptable as they meet our July 2, 1980 model TS criteria.
Diverse Containment Isolation The licensee has modified the containment isolation system so that diverse parameters will be sensed to ensure automatic isolation of non-essential systems under postulated accident conditions. These parameters are reactor building pressure and reactor coolant pressure. We have reviewed this system in our Lessons Learned Category "A" Safety Evaluation dated April 7, 1980.
The modification is such that it does not result in the automatic loss of con tainment isolation after the containment isolation signal is.
reset. Reopening of containment isolation would require deliberate operator action. The.TSs submitted by the licensee list each affected containment isolation valve and provide for the appropriate surveillance and actions in the event of component inoperability; therefore, we conclude that the TSs are acceptable.
Auto Initiation of Auxiliary Feedwater Systems The licensee has provided for the automatic initiation of auxiliary (emergency) feedwater flow on loss of normal feedwater flow. The auto-initiation signals used by the licensee are loss of main feedwater header discharge pressure and main feedwater pump control oil pressure. We have previously reviewed the design and installation of this system as part of our Lessons Learned Category "A" program. The circuits are designed to be testable and the design retains the capability of manual actuation from the control room even in the event of failure of the auto-initiating circuitry. The TSs submitted by the licensee list the appropriate components, describe the tests and provide for proper test frequency.
The TSs contain appropriate actions in the event of component inoperability; therefore, we conclude that the TSs are acceptable.
Auxiliary (Emergency) Feedwater Flow Indication The licensee has installed auxiliary (emergency) feedwater flow indication that meets our testability and vital power requirements..We reviewed this system in our Safety Evaluation dated April 7, 1980. The licensee has proposed a TS with 31-day ch Cl
'heck and annual channel calibration requirements. We.find this TS acceptable as it meets the criteria of our July 2, 1980 model TS criteria.
Our request indicated that the TSs related to minimum shift manning should be revised to reflect, the augmentation of an.STA. The licensee's application would add one STA to each shift to perform the function of.accident assess ment. The individual performing this function will have at least a bachelor's degree or equivalent in a scientific or engineering discipline with special training in plant design, and response and analysis of the plant for trans ients and accidents. The operating experience review function will be per formed by a group of on-site staff engineers who will keep the STA inforned of the results of the operational analysis function; this is in agreement with our April 7, 1980 Safety Evaluation. Based on our review, we find the licensee's submittal to satisfy our requirements and is acceptable.
Integrity of Systems Outside Containment Our letter dated July 2, 1980., indicated that the license should'be amended by adding a license condition related to a Systems Integrity Measurements Pro gram. Such a condition would require the licensee to effect an appropriate program to eliminate or prevent the release of significdnt amounts of radio activity to the.environment via leakage from reactor containment. By letter dated October 2, 1980, the licensee agreed to adopt such a license condition; accordingly, we have included this condition in the license.
Iodine Monitoring Our letter dated July 2, 1980, indicated that the license should be amended by adding a license condition related to iodine monitoring. Such a condition would require the licensee to effect a program which would ensure the capability to determine the airborne iodine concentration in areas requiring personnel access under accident conditions. By letter dated October 2, 1980, the licen see agreed to adopt such a license condition; accordingly, we have included this condition in the license.
Backup Method for Determining Subcooling Margin Our letter of July 2, 1980, indicated that the license should be amended by adding a license condition related to the determination of subcooling margin; this is a precursor to warn of inadequate core cooling in the event of an accident. Such a condition would require the training *of.personnel and the generation of procedures to accurately monitor the reactor coolant system sub cooling margin.
By letter dated October 2, 1980, the licensee agreed to adopt such a license condition; accordingly, we have included this condition in the license.
- c. Reporting Requirement for Generic Issues By letter dated May 29, 1980, from NRC to the licensee, we requested that Item (9) of Section C.2.a of Regulatory Guide 1.16, Revision 4, be added to Section 6.6.2.1. of the ONS Common TSs.
As noted in the Regulatory Guide, this item is intended to provide for reporting of potentially generic safety problems.
By letter dated October 20, 1980, the licensee submitted a request to add Item (9) to the TSs. As this addition fulfills the regulatory position of Regulatory Guide 1.16, we find the change acceptable.
-5 IV. ENVIRONMENTAL CONSIDERATION We have determined that the amendments do not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact. Having made this determination, we have further concluded that the amendments involve an action which is insignificant from the standpoint of environmental impact and, pursuant to 10 CFR §51.5(d)(4),
that an environmental impact statement, or negative declaration and environ mental impact appraisal need not be prepared in connection with the issuance of these amendments.
V. CONCLUSION We have concluded, based on the considerations discussed above, that:
(1) because the amendments do not involve a significant increase in the probability or consequences of accidents previously considered and do not involve a signi ficant decrease in a safety margin, the amendments do not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission s regulations and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Dated: January 28, 1981