ML20035F751
| ML20035F751 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 04/09/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20035F728 | List: |
| References | |
| NUDOCS 9304220234 | |
| Download: ML20035F751 (3) | |
Text
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o UNITED STATES E - c' NUCLEAR REGULATORY COMMISSION WASHWGT ON. D. C. 20555
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1 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGUIATION REl ATED TO AMENDMENT NO. 72 TO FACILITY OPERATING LICENSE NO. NPF-62 i
ILLINDIS POWER COMPANY SOYLAND POWER COOPERATIVE. INC.
i CLINTON POWER STATION, UNIT NO. 1 DOCKET NO. 50-461 1.0 INTE0 DUCT 10N The Shutdown Service Water (SX) system at the Clinton Power Station (CPS) provides cooling water to support multiple systems during all Operational Conditions. This also includes those times when the reactor vessel is defueled and irradiated fuel is being handled in the Fuel Handling Building or primary containment.
The SX system consists of three loops (A, B and C) and is generally aligned to electrical distribution Divisions I, II, and III.
The SX system provides cooling water to safety-related heat exchangers in support of emergency core cooling systems (ECCS), diesel generators, and residual heat removal (RHR) shutdown cooling.
In addition, the SX system provides room cooling for safety-related systems such as the control room ventilation system, DC battery rooms, and electrical distribution rooms.
The CPS Technical Specifications (TS) require that the SX loops be operable during all times when associated system (s) or components are required to be operable. Since safety-related systems are required to be operable during power operation, routine preventive maintenance and testing of the SX system is typically deferred to refueling outages.
Taking an SX loop out-of-service for maintenance and testing requires declaring the associated RHR shutdown cooling loop, ECCS, and main control room ventilation system inoperable.
Such actions must be factored into the outage schedule.
Technical Specification 3.0.4 states that entry into a new Operational Condition shall not be made unless the conditions for the Limiting Condition for Operation (LCO) are met without reliance on the provisions contained in the Action requirements. When the first reactor vessel head closure bolt is detensioned, the facility makes a " mode" change from Operational Condition 4 (COLD SHUTDOWN) to Operational Condition 5 (REFUELING). Since the current CPS TSs 3/4.7.1.1," Shutdown Service Water System (Loops A, B and C)," and 3/4.7.2, " Control Room Ventilation System," do not have exceptions to TS 3.0.4, these systems must remain fully operable for the above " mode" change.
The licensee's letter of December 15, 1992, states that critical path time must be added to the refueling outage schedule to account for the requirement 9304220234 930409 PDR ADOCK 0500 1
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' to delay the start of SX system maintenance until the reactor pressure vessel head has been removed and to account for delaying the reactor pressure vessel reassembly until required activites on the SX system have been completed.
The licensee states that this causes unnecessary restrictions on the refueling outage schedule and that the elimination of these restrictions will result in an approximate two-day savings in the duration of an average refueling outage.
Therefore, the licensee has requested to add an exception to TS 3.0.4 to modify TSs 3/4.7.1.1 and 3/4.7.2 to permit tensioning and detensioning of the reactor vessel head with one of the required divisions of the systems addressed by these TSs inoperable.
2.0 EVAltlATION The proposed change to TS 3/4.7.1.1, " Shutdown Service Water System (Loops A, j
B, C)," will only allow one required SX system loop to be inoperable while entering Operational Conditions 4 or 5.
The proposed change does not increase the amount of time that a SX system loop is inoperable during a refueling outage.
In addition, all three SX loops must still be operable prior to plant restart from the refueling outage.
The proposed change to TS 3/4.7.2, " Control Room Ventilation System," will only allow one of the two redundant systems to be inoperable while entering Operational Conditions 4 or 5.
The proposed change does not increase the amount of time that a control room ventilation system is inoperable during a refueling outage.
The impact of the proposed changes is limited to the potential effect on main control room air conditioning system availability and core decay heat removal during removal or installation of the reactor pressure vessel head. While the proposed changes will permit mode changes (via the reactor pressure vessel head removal / installation) without the full complement of SX systems or control room ventilation systems, the licensee will still maintain one SX loop associated with an operable diesel generator, DC power source, electrical power distribution system, and a control room ventilation system.
In addition, the TSs require two RHR shutdown cooling mode loops (or their alternates) while removing or installing the reactor pressure vessel head.
The licensee has made a thorough examination of the CPS TSs to identify those 4
systems that are supported by SX systems. Most of the systems are only required to be operable during Operational Conditions 1, 2, and 3, or they already have exceptions to TS 3.0.4.
The licensee has determined that the l
proposed changes are consistent with allowances for plant mode changes provided in NRC Generic Letter 87-09, which addressed unnecessary restrictions on mode changes by Specification 3.0.4.
The staff finds that issues associated with shutdown risk are not affected by l
the proposed changes. The proposed changes do not permit the initiation of handling irradiated fuel in the secondary containment with one or more main control room ventilation systems inoperable.
In addition, the proposed l
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l 3-l changes do not change the shutdown operability requirements of the diesel j
generators, safety-related batteries, or the electrical distribution systems.
The licensee has also addressed the design basis accident analyses associated with plant shutdown conditions and concluded that the proposed changes do not offect them.
t Based on our review, the staff finds that the licensee has adequately
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addressed the safety significance of the proposed changes and, therefore, finds them acceptable.
3.0 STATE CONSULTATION
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In accordance with the Commission's regulations, the Illinois State official l
was notified of the proposed issuance of the amendment. The State official i
had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
This amendment changes a requirement with respect to 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 t
exposure. The Commission has previously issued a proposed finding that the l
amendment involves no significant hazards consideration and there has been no public comment on such finding (58 FR 6999). 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 i
or environmental assessment need be prepared in connection with the issuance of the amendment.
5.0 CONCLUSION
4 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 Contributor: Douglas V. Pickett Date:
April 9, 1993 6
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