ML20099E834
| ML20099E834 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 07/30/1992 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20099E829 | List: |
| References | |
| NUDOCS 9208110338 | |
| Download: ML20099E834 (3) | |
Text
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UNITED STATES n
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NUCLEAR REGULATORY COMMISSION WASHINPToN. D.C. 20506 SAFETY EVALVAILON BY TH! 0FFICE OF NUCLEAR REACTOR REGULATION PELATED TO AMENDMENT N0. 64 TO FAClllTY OPERATING LICENSE N0. NPF-62 JM INDIS POWER COMPANY. ET AL, fLINTON POWER STATION. UNIT NO. 1 D_0CKET Nd. 50-461
1.0 INTRODUCTION
By lctter dated December 17, 1990 and supplemented December 17, 1991, Illinois Power Company requested ch:. ages to the Clinten Technical Specification (TS)
Section 3/4.3.4.1, Anticipated Transient Wit iut Scram Recirculation Pump Trip (ATWS-RPT) system instrumentation to comply th the requirements of 10 CFR 50.62. The actuation logic for the Clinton ;
S-RPI is based on a trip system with two-oilt-of-two high reactor pressure s' als or two-out-of-two low-low reactor water level signals.
These are ree-tant trip systems.
Each trip system will automatically trip both pumps.
3.3,4.1 requires both reactor pressure channf ' and both reactor water le channels in each trip system to be operable while in Operational Condition Run Mode). Y lon (h) of TS 3.3.4.1 currently allows one channel in one ip system t-4 inoperable for up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />; otherwise, the plant must tt at least u, mtional Conditica 1
2 (Startup Mode) within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
The licensee proposed to replace the existing Action statement (b) with a new action statement and add new Action statements (c) and (d) that are consistent with other BWR/6 plants.
In addition, the licensee requested an exemption from the provision of TS 3.0.4.
This exemption will allow plant startup with one or more channels inoperable in the RPT system.
2.0 EALVATION The existing TS 3.3.4.1 Action statement (b) states that "With the number of OPERABLE channels one less than required by the M M mum OPERABLE Channels per Trip System requirement for one trip function in c..' Trip System, restore the inoperable channel to OPERABLE status within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or be in at least STARTUP within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />." The licensee proposed to replace the existing Action statement (b) with a new Action statement (b) and add Action Stements (c) and (d), as follows:
b.
With the number of OPERABLE channels less than required by the Minimum OPERABLE Channels per Trip System requirement for one trip system, place the inoperable channel (s) in the tripped conditinn within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least STARTUP within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
The provisions of TS 3.0.4 are not applicable.
9208110338 920730 PDR ADOCK 0500 1
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2 With the number of OPERABLE channels one less than required by the-c.
Minimum OPERABLE Channels per Trio System requirement for both trip systems,-place at least one inoperable channel in the tr_ipped condition within one hour, _ and place the second inoperable channel in the tripped condition within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Otherwise,-be-in at least STARTilP within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
The provisions of TS_3.0.4 are not applicable.
d.
With both trip systems otherwise inoperable, restore at least one trip system to OPERABLE status within one hour or be in at least STARTUP within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
The staff recogr.izes that, with the redundant trip systems arrangement, a channel inoperable-in one trip system will not prevent the RPT actuation (i.e.,-it-will not lose RPT function), and it is still safe to operate the plant in RUN mode.
With one channel inoperable for one trip system --the proposed 72_ hours limit is a reasonable time to repair the inoperable channel and is consistent with the draft BWR standard TS. _However, the. proposed wording "The provisions'of.TS 3.0.4 are not applicable" in Action Statement (b) is not acceptable._ TS 3.0.4 establishes limitations on a change in OPERATIONAL' CONDITIONS when a Limiting Londition for Operation (LCO) is not met.
It precludes pla-ing the facility in a higher wCITPN of operation when the requirements for a LC0 are not met and-continued noncompliance b these conditions would result in a shutdown-to comply witF the ACTION requirements if a change in CONDITIONS were permitted. The purpos!.#
this TS is to ensure that facility operation is not initiated or.that-high w CONDITIONS of operation are not entered when corrective action is being taken.
This is consistent with'the staff position in' Generic Letter 87-19.
The ATWS recirculation pump trip is an important safety ~ feature and should be fully-operational prior.to changing plant conditions. The provisions of TS 3.0.4 are applicable to LCO 3.3.4.1 and, by letter dated December 17, 1991, the licensee has withdrawn the original request to change the reference to the provisions of TS 3.0.4.
The proposed Action Statement (c) addresses the conoition when the number of OPERABLE channels are-one less than required for both trip systems.- By_ placing at least one inoperable channel in the trip condition within 1-hour, the risk of incapability to_ initiate the ATWS-RPT function,is limited to the 1-hour time period. The staff finds that during the 1-hour time period plus the 6-hours for bringing the plant to the STARTUP-mode, the probability of-_failing RPT actuation coincident with an ATWS event-is very low.
Statement:(c) also requires placing the second inoperable channel in the tripped condition within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This is the same condition as covered by Action:(b)'.
The proposed actions-are consistent with the draft BWR standard TS being implemented in the improvei Technical' Specification program. However, the proposed wording "The provisions of-TS 3.0.'4 -
- are not applicable" in Action Statement:(c) isinut acceptable for the same reason as stated above for denying in Action Statement (b).
The licensee has also withdrawn this proposed change by letter dated December 17,_1991.
The proposed' Action Statement (d) addresses the case in which both trip systems are inoperable-for reasons other than addressed by proposed Action Statement (c).
In this case, the proposed Action (d) requires at least one tr9 system to be m
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restored to operable status within 1-hour.
With one trip system restored, continued operation would be governed by proposed Action (b).
If one trip system-is not restored within 1-hour, the plant must-be in at least:Startup within the next 6-hours. The proposed Action (d) is justified based on the limited period of time for continued plant operation with both-ATWS-RPT trip systems inoperable and the low probability-of an event oteurcing that requires. actuation of this-system during this short time peciod.
The staff finds the. proposed Action'(d) acceptable.
The wording change on Footnote. (a) of TS Table 3.3.4.1-1 allows one trip system to be placed in an inoperable status for up to-two hours for required surveillance when the redundant trip system is operable.
The-staff finds this acceptabl e..
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the appropriate Illinois State official was notified of the proposed issuance _of the amendment. -The State official had no comments.
4.0 -ENVIRONMENTAL-CONSIDERATION Pursuant to 10 CFR 51.21, 51.32, and 51.35,.an environmental assessment and -
finding of significant impact'has been prepared and published in the Federal Reaister on May 31, 1991 (57 FR 6747). Accordingly, based upon the environmental assessment, the Commission has determined that the issuance of this-amendment will not have a significant effect on the quality of the-human environment.
5.0 CONCLUSION
The staff 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 Contributors: H. Li J. Lombardo-Date: July - 30, -.1992
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