ML20071L238
| ML20071L238 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 07/25/1994 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20071L237 | List: |
| References | |
| NUDOCS 9408030035 | |
| Download: ML20071L238 (4) | |
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NUCLEAR REGULATORY COMMISSION g v WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.189 TO FACILITY OPERATING LICENSE NO. DPR-50 METROPOLITAN EDIS0N COMPANY JERSEY CENTRAL POWER & LIGHT COMPANY PENNSYLVANIA ELECTRIC COMPANY GPU NVCLEAR CORPORATION THREE MILE ISLAND NVCLEAR STATION. UNIT NO. 1 DOCKET NO. 50-289
1.0 INTRODUCTION
On February 25, 1993, GPU Nuclear Corporation (GPUN or the licensee) submitted Licensee Event Report (LER)93-001 concerning the failure of a pressure switch during performance of a monthly surveillance. The assessment of the safety consequences and implications of the event stated that Technical Specification (TS) Table 3.5-1, " Instruments Operating Conditions," does not provide for an allowable outage, time for the listed instrumentation, nor does it account for the redundant trains of instrumentation. The LER also found that the requirements of TS Table 3.5-1 were inappropriate and inconsistent with the requirements of TS 3.3.2, where it specifies an allowable outage time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for mechanical components in one train and the redundant train is assumed to be fully operational.
Part of the corrective action planned included reviewing and requesting changes to the requirements in TS Table 3.5-1.
The licensee requested changes to Table 3.5-1 in a letter on March 2, 1994.
2.0 EVALUATION (1) Pages 3-27a, 3-29, 3-30 and 3-30a
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Column (C) of Table 3.5-1 is revised to replace the term " Maintain hot shutdown" with a new footnote (a). The footnote (a) states that if the conditions of Columns (A) and (B) cannot be restored within I hour, the unit must be placed in HOT SHUTDOWN within an additional 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
The staff finds that the change to Column (C) provides sufficient time to place an inoperable instrumentation channel in either the trip or bypass condition and also specifies a clear allowed outage time for action required by the TS.
In addition, the 1-hour allowed outage time is sufficient to correct minor problems. The staff also finds that the change is consistent with NUREG-1430,
" Standard Technical Specifications" for Babcock & Wilcox (B&W) plants and is, therefore, acceptable.
9408030035 940725 PDR ADOCK 05000289 P
, The second sentence of the Bases for TS 3.5.1 on page 3-27a is deleted.
Since this discussion merely repeats the requirements of TS 3.5.1.1, the staff finds the change to be administrative.
The minimum number of required operable power range instrumentaticn channels on page 3-29 is revised from three to two. There are four reactor protection l
I channels and normal trip logic is two-out-of-four. If one or more function in l
two protection channels become inoperable, one of two inoperable channels must l
be placed in trip and the other in bypass. This will place the reactor i
protection system (RPS) in a one-out-of-two logic.
In this configuration, the l
RPS can still perform its safety functions in the event of a single channel failure. The staff finds that the change is consistent with NUREG-1430 and is, therefore, acceptable.
On page 3-30a, the unit is required to maintain indicated reactor power less l
than 7% if minimum conditions for operation are not met for the loss of i
feedwater instrument and less than 45% if minimum conditions for operation are l
not met for the turbine trip instrument. However, there is no allowed outage i
time specified to attain the reduced power condition if reactor power is above these limits and the minimum conditions are not met.
The licensee has l
proposed an allowed outage time of I hout and an additional 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to reduce power in an orderly manner to remove any uncertainty regPrding compliance with this requirement. The staff finds that the change is consistent with NUREG-1430 and is, therefore, acceptable.
(2) Pages 3-31, 3-32, 3-32a and 3-32b Footnote (a) replaces some of the required Operator Actions in Column (C).
It provides a 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> allowed outage time to reestablish the conditions of Columns (A) and (B).
If the conditions of Columns (A) and (B) cannot be restored within I hour, the unit must be in HOT SHUTDOWN within an additional 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The staff finds that the change is consistent with the completion times specified in NUREG-1430 and is, therefore, acceptable.
Footnote (b) allows reduction of the degree of redundancy for surveillance j
testing during which the Engineered Safety Actuation System (ESAS) channels have a two-out-of-two trip logic. This allowance is based on the inability to perform the surveillance within the time allowed in Footnote (a). The staff finds that the 8-hour allowance is reasonable and the change is consistent with the associated completion time and surveillance allowance specified in NUREG-1430. The staff finds the change, therefore, acceptable.
Column (C) of the ESAS manual actuation instrument channels is revised to specify an allowed outage time for this function. The revision provides a 72-hour period to restore one inoperable manual initiation channel and clarify that there are separate manual actuation switches for the 4 psig and 30 psig Reactor Building high pressure isolation features.
The change is consistent with NUREG-1430 and the staff, therefore, finds it to be acceptable.
- The Reactor Building (RB) spray system (BS) consists of two redundant trains of three pressure switches each, in a two-out-of-three logic circuit, to actuate BS and RB isolation when RB pressure reaches a predetermined setpoint.
The licensee has concluded that the present TS for operability regarding these systems are inappropriate because they do not recognize the independence of the two channels of actuation. Therefore, an allowed outage time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> has been proposed consistent with TS 3.3.2 and 3.3.4, which allow components to be removed from service for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> provided the redundant component is verified to be operable. This change is consistent with NUREG-1430 and the staff, therefore, finds it to be acceptable.
The license has proposed adding footnote (c) to Table 3.5-1 to allow restoration of the minimum number of operable pressure switches in the 30 psig Reactor Building isolation circuitry. The footnote allows 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> if one train is affected and 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> if both trains are affected before shutdown completion times are invoked. The proposed times are consistent with TS 3.3.6 which allows 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> to restore an inoperable RB isolation valve. Therefore, the staff finds this change to be acceptable.
Footnote (f) on page 3-32a is revised to supply an allowed outage time period for radiation detector RMA-9. This instrument provides a backup signal to shut the RB purge valves when high radiation levels are detected in the RB.
These purge valves have redundant safety-grade automatic actuation from both the ESAS and reactor trip signals. The licensee concluded that it was acceptable to allow an 8-hour time period for RMA-9 to be out of service to allow confirmation of the alarm and minor troubleshooting, if necessary. This conclusion was based on the redundant nature of RMA-9's function, since it is not the primary signal relied upon to shut the RB purge valves. The staff agrees with the licensee's determination and, therefore, finds the change to be acceptable.
(3) Pages 3-27, 3-32c and 4-5 Changes on page 3-27 provide clarification on Column (C) guidance and allowed use of the key operated channel bypass switch. Changes on page 3-32c delete a footnote which states that it is only applicable for Cycle 6 and modify Column (C) and Footnote (a) to be consistent with the format of other changes made in the licensee's submittal. Changes on page 4-5 provide clarification for the description of the reactor building pressure switches and make a grammatical correction on item 20. The staff finds that these changes are administrative in nature and are acceptable.
2.1
SUMMARY
The proposed amendment permits time to restore instrumentation channels to operable status consistent with times presently allowed for ot:tage of other safety-related equipment affecting one train. The staff concludes that the changes are consistent with NUREG-1430 and would not significantly reduce a margin of safety and are, therefore, acceptable.
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3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the ' Pennsylvania State official was notified of the proposed issuance of the amendment. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendment changes requirements 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 or types of 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 (59 FR 17600). Accordingly, the amendment meets the eligibility criteria for I
(.ategorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to l
10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
5.0 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 erhngered by operation in the proposed manner, (2) such activities will be cenducted in compliance win 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:
C. Chung Date:
July 25, 1994
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