ML20136D820
| ML20136D820 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 03/05/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20136D819 | List: |
| References | |
| NUDOCS 9703130029 | |
| Download: ML20136D820 (5) | |
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j NUCLEAR RESULATCRY CEMMISSION f
WA&HINGTON. C.C. 20086-0001 o
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACT 0r REEULATION RELATED TO AMENDMENT NO.126 TO FACILITY OPERATING LI
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SOUTHERN CALIFORNIA EDISON COMPANY i
SAN DIEGO GAS AND ELECTRIC COMPANY 4
THE CITY OF RIVERSIDE. CALIFORNIA
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THE CITY OF ANAHEIM. CALIFORNIA l
SAN ON0FRE NUCLEAR GENERATING STATION. UNIT 3 DOCKET NO. 50-362
1.0 INTRODUCTION
By application dated February 7,1997, Southern California Edison Company (SCE or the licensee) requested a change to the Technical Specifications (Appendix A to Facility Operating License No. NPF-15) for San Onofre* Nuclear Generating Station, Unit No. 3.
The proposed change would defer implementation of Surveillance Requirement (SR) 3.1.5.4 of TS 3.1.5, " Control Element Assembly (CEA) Alignment," until the next SONGS Unit 3 shutdown, which will be no later than the upcoming Cycle 9 refueling outage (currently scheduled for April 12, 1937).
2.0 BACKGROUND
On February 6, 1997, SCE provided its written request for discretionary enforcement from the requirement of SR 3.1.5.4 of TS 3.1.5.
The enforcement discretion was requested until the NRC could approve on an exigent basis a license amendment which would defer implementation of SR 3.1.5.4 until the next SONGS Unit 3 shutdown.
The need for granting this enforcement discretion, and issuing a follow-up TS amendment, results from an administrative error in the implementation of the Technical Specification Improvement Program (TSIP) approved by the NRC (NRC Amendment No.116 for SONGS Unit 3, issued February 9,1996) and implemented by SCE on August 5, 1996. During the TSIP project, SCE personnel incorrectly believed that SR 3.1.5.4 was satisfied by a surveillance conducted during the previous SONGS Unit 3 refueling outage. SR 3.1.5.4 states, " Perform a CHANNEL FUNCTIONAL TEST (CFT) of each reed switch position transmitter channel," and the frequency of this SR is every 24 months. The previous surveillances
' performed on these channels consisted of simulatirig an input for each reed switch position transmitter into each control element assembly (CEA) calculator, and verifying the correct response of each CEA calculator.
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order to comply with the current SR 3.1.5.4, the licensee concluded that each CEA has to be exercised over its entire length of movement. Therefore, the i
unit was not in compliance with the current TS shortly after their i
implementation on August 5,1996.
It is not possible to perfom this functional test with the unit in Mode 1.
Therefore, the licensee requested relief from performing the CFTs needed to demonstrate compliance with SR 3.1.5.4 until no later than the upcoming i
scheduled refueling outage. The licensee committed, in its letter dated February 6,1997, to test the reed switch position channels in accordance with 4
i SR 3.1.5.4 in the event of a planned or unplanned shutdown ~ of Unit 3 before the refueling outage. The licensee's safety rationale for this request is that the recent operational history and inherent reliability of the Unit 3 reed switch position transmitters provide adequate assurance that the transmitters are operable and fully capable of performing their intended i
safety function. The enforcement discretion would avoid an undesirable transient associated with an unnecessary plant shutdown and thus minimize j
potential safety consequences and operational risks associated with such action.
In a letter dated February 10, 1997, the NRC documented its granting of the enforcement discretion until the issuance of a TS amendment to resolve this issue.. The NRC granted this Notice of Enforcement Discretion (N0ED) pursuant to the NRC's policy regarding exercise of discretion for an operating i
facility, set out in Section VII.c of the " General Statement of Policy and Procedures for NRC Enforcement Actions" (NUREG-1600). This TS amendment would j
defer implementation of SR 3.1.5.4 to no later than the SONGS Unit 3 Cycle 9 l
refueling outage (currently scheduled to begin on April 12,1997).
s In its granting of enforcement discretion, the staff concluded that the licensee had provided sufficient information on the adequacy of the reed switch position channelt to demonstrate that these channels can perform their l
intended safety function for the limited period of time before the next refueling outage. This information is discussed in detail in Section 3.0 of this safety evaluation. The staff agrees with the licensee that an unnecessary plant shutdown constitutes an undesirable transient involving a l
small amount of risk and, therefore, considers the option of requiring. a j
shutdown specifically to perform SR 3.1.5.4 to be unwarranted.
3.0 EVALUATION 1
The staff evaluated the safety consequences of allowing Unit 3 to continue operation until its next refueling outage without compliance with SR 3.1.5.4 l
along with other mitigating information that is available, and compared this i
to the. mall, but measurable amount of risk associated with an unnecessary i
plant shutdown. The staff concluded that the option that resulted in the minimum safety im>act was the option of allowing the surveillances to be
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postponed until tie upcoming refueling outage.
i During startup, normal operations, and shutdown activities involving CEA i
movement, the CEA calculators will sound an annunciator in the control room i
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should a CEA deviate from its subgroup position by more than 5 inches. The licensee has stated that there have been no deviation alarms attributable to i
L failures of the read switch position channels during Cycle 8 operation, which
' ncluded several startups and shutdowns.
If appropriate, the CEA calculators i
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will transmit penalty factors to the core protection calculators that will i
cause trip setpoints to be approached. When the CEAs are at the fully
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withdrawn _ position, the cross channel check performed shiftly provides j
assurance that there is no pair of reed switches failed in the closed position below the CEA position.
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The reed switch position transmitter assemblies are considered highly reliable because the only active components are the magnetically actuated reed switches. The magnet attached to the CEA extension shaft closes two pairs of reed switches with all of the other reed switches normally open.
If a pair of f
reed switches were to stick in the closed position, the channel would not
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function properly and the failure would be detected by the cross channel check j
procedure discussed above.
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.The staff concludes that the combination of factors discussed above provides i
adequate assurance, for the limited period of time before the next refueling outage, that the reed switch position channels can perform their intended i
safety function. The staff agrees with the licensee that an unnecessary plant 4
i shutdown constitutes an undesirable transient involving a small amount of risk and, therefore, considers the option of requiring a shutdo,wn specifically to perform SR 3.1.5.4 to be unwarranted.
The specific TS change consists of adding a note to SR 3.1.5.4, that states, "This SR is not applicable until return to Mode 2 from the Unit 3 Cycle 9 refueling outage with the additional commitments made in Edison letter dated February 6, 1997. The safety justification for not complying with this SR is included in the February 6, 1997 letter." As stated in Section 2.0 of this safety evaluation, the February 6,1997, letter contains the licensee's commitment to test the reed: switch position channels in accordance with SR 3.1.5.4 in the event of a planned or unplanned shutdown of Unit 3 before the refueling outage. The statement made in the note that'the SR is not applicable until return to Mode 2 from a shutdown is acceptable since TS 3.1.5 only applies to Modes 1 and 2 plant operation.
4.0 EXIGENT CIRCUMSTANCES
The Commission's regulations,10 CFR 50.91, contain provisions for issuance of amendments when the usual 30-day public notice period cannot be met. One type of special exception is an exigency. An exigency is a case where prompt action is required (before the expiration of a 30-day period comment period).
Under such circumstances, the Comnission notifies the public in one of two
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ways: by issuing a Federal Reaister notice providing an opportunity for hearing and allowing at least_ two weeks for prior public comments, or by issuing a press release discussing the proposed changes, using the local media.
In this case, the Commission used the first approach.
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i The exigent circumstances for this TS amendment request exist due to the recent discovery of the inappropriate crediting of previous test results to l
the post-TSIP SRs.
Processing this TS amendment request on an exigent basis also ends the need for the Notice of Enforcement Discretion issued by the j
staff on February 10, 1997, described in Section 2.0 of this evaluation.
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The NRC staff has reviewed the circumstances surrounding the amendment request and finds that the circumstance; could not have been avoided and the licensee
- made a timely request for the an andment. Therefore, the staff finds that the i
license amendment may be issued in an exigent manner pursuant to 10 CFR l
50.91(a)(6).
There were no public comments in response to the notice published in the Federal Reaister.
I 5.0 BASIS FOR FINAL NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION 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 l
hazards considerations 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 accident j
previously evaluated; or (3) involve a significant reduction in a margin of safety.
1.
The proposed change does not involve a significant increase in the i
probability or consequences of an accident previously evaluated.
l The proposed change would defer the implementation of SR 3.1.5.4 of TS 3.1.5 until no later than the upcoming Unit 3 refueling outage. Operation of the i
facility would remain unchanged as a result of the proposed changes and no 1
assumptions or results of any accident analyses are affected. Based on testing, operating experience, and the inherent reliability of the system, the staff concludes the reed switch position transmitters have demonstrated their i
capability to perform their specified safety function and are considered operable for the limited period of time until the next Unit 3 shutdown.
Therefore, the proposed change will not involve a significant increase in the probability or consequences of any accident previously evaluated.
2.
The proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
The proposed change would defer the implementation of SR 3.1.5.4 of TS 3.1.5 until no later than the upcoming Unit 3 refueling outage. Operation of the facility would remain unchanged as a result of the proposed change. The reed switch position transmitters cannot initiate an accident. Therefore, the proposed change will not create the possibility of a new or different kind of accident from any accident previously evaluated.
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3.
The proposed change does not involve a significant reduction in a margin of safety.
The proposed change would defer the implementation of SR 3.1.5.4 of TS 3.1.5 until no later than the upcoming Unit 3 refueling outage.
The staff concludes that the reed switch position transmitters are able to perform their safety function and are considered operable for the limited period of time until the i
next Unit 3 shutdown. Therefore, the proposed change will not involve a significant reduction in a margin of safety.
Based upon the above considerations, the staff concludes that the amendment meets the three criteria of 10 CFR 50.92. Therefore, the staff has made a i
final determination that the proposed amendment does not involve a significant hazards consideration.
6.0 STATE CONSULTATION
l In accordance with the Commission's regulations, the California 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 requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. 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 (62 FR 7477). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR l
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 the amendment will not be inimical to the common
. defense and security or to the health and safety of the public.
Principal Contributor:
M. Fields, PDIV-2/NRR Date:
March 5, 1997
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