ML20078Q291
| ML20078Q291 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 02/14/1995 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20078Q289 | List: |
| References | |
| NUDOCS 9502210190 | |
| Download: ML20078Q291 (5) | |
Text
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"g UNITED STATES E
NUCLEAR REGULATORY COMMISSION E
4f WASHINGTON, D.C. 2000640M SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 86 TO FACILITY OPERATING LICENSE NO. NPF-18 COMMONWEALTH EDIS0N COMPANY i
i LASALLE COUNTY STATION. UNIT 2 DOCKET NO. 50-374
1.0 INTRODUCTION
By letter dated January 30, 1995, Commonwealth Edison Company (Comed, the licensee) requested an amendment to Facility Operating License No. NPF-18 for LaSalle County Station, Unit 2.
The proposed amendment adds o footnote to Technical Specification Table 4.3.1.1-1 to allow 4 one-time extension of the surveillance interval for the main steam line isolation vahe (MSIV) closure reactor protection system channel functional test. This extension averts the need to perform the functional test prior to the start of the upcoming Unit 2 refueling outage.
2.0 BACKGROUND
Due to a problem discovered with the LaSalle, Unit 2, MSIV limit switches, the licensee performs a visual inspection following movement of the valves in order to verify that the switches are reset to the " Spring Return-to-Normal" position. The licensee discovered in January 1994 that the limit switches may not ahays automatically return the limit switch arm to the normal position after being toggled during valve strokes.
To perform the visual verification of the resetting of the limit switches, personnel must enter containment.
The unit must reduce power to less than 25 percent core thermal power (CTP),
the containment is de-inerted, and personnel are subject to radiation doses on the order of 200 millirems.
The change from monthly to quarterly functional test interval for the MSIV -
Closure scram and the change from monthly to weekly functional test interval for the Manual Scram function was submitted as an exigent change and approved as Amendment Nos. 95 and 79 for LaSalle, Units I and 2.
The request was made to allow continued operation of Unit 2 and provide Comed more time to correct I
the limit switch problem without excessive power cycling and personnel dose due to the original monthly surveillance test interval (STI).
Since the approval, the MSIV - Closure scram functional test surveillance has been i
performed three times during forced outages and one time during a load drop to 21 percent power. A modification to resolve the limit switch problem was ready for installation for a Unit 2 maintenance outage planned for A:e 1994; however, due to forced outages and the extension of the Ureit I sixth refueling outage, the Unit 2 maintenance outage was postponed.
The forced outages that 9502210190 950214 PDR ADOCK 05000374 P
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have occurred have been of insufficient planned duration to do the necessary l
modification.
All MSIV limit switches were in the " Spring Return-to-Normal" position after the most recent functional test on October 23, 1994, when LaSalle, Unit 2, was starting up from a forced outage. Therefore, the reactor protection system (RPS) limit switches for the MSIV - Closure Scram are currently operable.
However, the position of the MSIV limit switches would be unknown, without visual observation, after cycling the MSIVs during the next scheduled channel functional test.
Therefore, LaSalle, Unit 2, would need to reduce power to less than 25 percent core thermal power, approximately 200 MWe, in order to allow personnel access to the primary containment drywell to verify proper MSIV limit switch position in the " Spring Return-to-Normal" position.
The quarterly channel functional test is due again at the maximum of 1.25 times the current 92 day STI at 02:45 a.m. CST on February 15, 1995.
3.0 EXIGENT CIRCUMSTANCES
The Commission's regulations, 10 CFR 50.91, contain provisions for issuance of amendments when the usual 30-day public notice period can not be met. Where the Commission finds that an emergency situation exists, in that failure to act in a timely way would result in a significant loss of electrical output, it may issue an amendment involving no significant hazards consideration without prior notice and opportunity for a hearing or for public comment. The subsequent notice of issuance will provide for opportunity for a hearing and for public comment after issuance. The Commission may also find that exigent circumstances exist such that an amendment involving no significant hazards consideration does not permit the usual 30-day public notice period, but can utilize an alternative method of providing a reasonable opportunity for the public to participate.
These alternative methods include: (1) publication of a Federal Reaister notice of an opportunity for hearing and allowing at least two weeks for prior public comment, or (2) the use of local media to provide reasonable notice to the public in the area surrounding a licensee's facility of the proposed licensing action, including the staff's proposed no significant hazards consideration determination, and a description of the means to provide prior comment.
Following preliminary discussions with the staff, the licensee submitted an application dated January 30, 1995, and requested treatment under the emergency provisions of 10 CFR 50.91(a)(5).
Upon receipt of the submittal, the staff determined that adequate time was available to treat the request as an exigent request in accordance with 10 CFR 50.91(a)(6)(1)(B).
In order to provide a reasonable opportunity for the public to comment on the proposed licensing action, legal notices were published in the Morris Daily Herald, Ottawa Daily Times, and Streator Times-Press newspapers in or near LaSalle County, Illinois.
During a review of surveillance tracking information on January 19, 1995, the licensee discovered a previous oversight in that the MSIV - Closure reactor protection system channel functional test was found to be due prior to the i
upcoming Unit 2 refueling outage. An assessment following the previous performance of the surveillance, on October 23, 1994, had concluded that the surveillance would not be required during the remainder of the current operating cycle.
Following the discovery of the scheduling issue, the licensee held various meetings to consider alternatives.
It was decided that a licensing amendment using the emergency or exigent provisions of 10 CFR 50.91 was appropriate in order to avoid the cycling of plant systems and the collection of radiation doses by plant personnel. The license amendment was developed and submitted on January 30, 1995. The staff finds that the licensee used its best efforts to make a timely application following the discovery of the problem and that exigent circumstances do exist and were not the result of any intentional delay on the part of the licensee.
4.0 EVALUATION The proposed change involves the extension of a surveillance test interval by several days in that the surveillance can be postponed until the upcoming refueling outage. Amendment Nos. 95 and 79 for LaSalle County Station, Units 1 and 2, revised the HSIV - Closure Scram RPS functional test from a monthly interval to a quarterly interval. The bases for these amendments were the staff's previous review of the General Electric (GE) Topical Report, "BWR Owner's Group Technical Specification Improvement Analysis for BWR Reactor Protection System," (NEDC-30851P-A) and the plant specific analysis which confirmed the generic study's applicability to LaSalle. The plant specific study was presented in the January 28, 1994, submittal which supported the requested change from monthly to quarterly testing intervals for the MSIV -
Following issuance of the amendments, the channel functional test interval for the MSIV - Closure Scram RPS function was defined as at least once every 92 days with a maximum allowable extension, in accordance with TS 4.0.2., not to exceed 25 percent of the 92 day interval.
The generic studies performed by GE and the verification of the applicability of those studies for LaSalle, conclude that an increase of the channel functional test interval from the current 115 days (92 days with maximum 25 percent extension) to the maximum proposed 120 days does not significantly increase the RPS failure frequency. Although these studies were performed to assess general changes in testing intervals with consideration of risk tradeoffs associated with component wearout, reduced system redundancy during testing, and human errors, they also support this amendment request in that failure frequencies were found to not increase dramatically as a result of assumed increases in testing intervals.
In addition to the factors discussed above, this specific amendment request introduces risk tradeoffs such as the need to perform power changes, de-inert containment, and the placement of plant personnel in radiation areas.
Considering the current problems with performing the HSIV - Closure Scram RPS channel functional test at LaSalle, Unit 2, and the minimal safety benefit of performing the test during the last days of the current operating cycle, the staff finds the proposed change acceptable.
The licensee has stated that the problems with the MSIV limit-switches which introduce these hardships will be
corrected by a plant modification to be performed during the upcoming refueling outage.
5.0 FINAL NO SIGNIFICANT HAZARDS CONSIDERATION
The Commission's regulations in 10 CFR 50.92 state that the Commission may make a final determination that a license amendment involves no significant hazards consideration if operation of the facility in accordance with the amendment would not: (1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any previously evaluated; or (3) involve a significant reduction in a margin of safety. The staff has evaluated the proposed amendment against the three factors as part of the determination:
1.
Does not involve a significant increase in the probability of consequences of an accident previously evaluated.
The change results in a small, one-time increase of the STI for the actuation instrumentation supporting the MSIV - Closure Scram RPS function. There are no changes in the affected system itself.
Since the change does not significantly affect the reliability of the system or the nature of its operation, the probability and the consequences of analyzed accidents are not increased. The proposed one-time chenge is bounded by the topical report evaluation of extended test intervals which has been used to justify the quarterly surveillances.
The brief extension of the MSIV - Closure Scram RPS function does not, therefore, involve a significant increase in the probability or consequences of an accident previously evaluated.
2.
Does not create the possibility of a new or different kind of accident from any previously evaluated.
The proposed change increases the STI for MSIV - Closure Scram RPS instrumentation, but does not actually change the instrumentation of this system.
Likewise, the slight extension of the testing interval does not introduce any revised operating practices.
Since there are no such changes, the proposed amendment does not create the possibility of a new or different kind of accident from any previously evaluated.
3.
Does not involve a significant reduction in the margin of safety.
The proposed change does not change actuation setpoints in the above mentioned system or alter the levels of redundancy.
Setpoints are based upon the drift occurring during an 18-month calibration interval. The proposed change is bounded by the analyses of NEDC-30851P-A as referenced by the LaSalle, Unit 2, Technical Specification Bases for Specification 3/4.3.1. These analyses, which were prepared by GE and approved by the NRC, examined the effects of extending STI and found that the proposed changes would not involve a significant reduction in a margin of safety.
Based upon the above considerations, the staff concludes that the amendment involves no significant hazards consideration.
6.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Illinois State official was notified of the proposed issuance of the amendment.
The State official had no comments.
7.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a surveillance requirement. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding. The proposed finding was issued in the local media described in Section 3.0 of this Safety Evaluation. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
8.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
W. Reckley Date: February 14, 1995
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D. L. Farrar -
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A copy of the Safety Evaluation is also enclosed. The Notice of Issuance will be included in' the Commission's biweekly Federal Reaister notice.
Sincerely, i
original signed by l
i William D. Reckley, Project Manager -
Project Directorate III-2 l
Division of Reactor Projects - III/IV Office of Nuclear Reactor Regulation Docket No. 50-374 l
Enclosures:
1.
Amendment No.
to NPF-18 l
2.
Safety Evaluation cc w/encls:
see next page i
i l
i Q11TRIBUTION:
l Docket File PUBLIC i
PDIII-2 r/f J. Roe l
R. Capra C. Moore l
W. Reckley OGC l
G. Hill (2)
OC/LFOCB C. Grimes ACRS (4)
OPA B. Clayton RIII k'
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DOCUMENT NAME:
LASALLE\\LA91424.AMD To receive a c%y of this d>cument, indicate in the box:
"C" = Copy without enclosures *E" = Copy with enclosu
= No copy 3
0FFICE i AiP $1142 l U PM:PDIII-2 E
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WRECKLEY \\ A.H34 RCAPRA tot.
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DATE 02M /95 02/ t' /95 02/14/95 02/4/95 OE
/95 02/#/95 0FFICIAL RECORD COPY I
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