ML20236P536
| ML20236P536 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 08/10/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20236P531 | List: |
| References | |
| TAC-62757, TAC-62758, NUDOCS 8708120408 | |
| Download: ML20236P536 (4) | |
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_ SAFETY EVALUATION BY THE OFr.:CE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDhl.NTS NOS.144 AND 79 TO FACILITY OPERATING LaCENSES DPR-57 AND NPF-5 GEORGIA POWER COMPANY OGLETHORPE POWER CORPORATION M'JNICIPAL ELECTRIC AUTHORITY OF GEORGIA CITY OF DALTON, GEORGIA EDWIN 1. HATCH NUCLEAR PLANT, UNITS 1 AND 2
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DOCKET NOS. 50-321 AND 50-366 i
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INTRODUCTION By letter dated August 25,1986, (Reference 1) Georgia Power Company (GPC; the licensee) requested changes to Table 3.2-1 of the Hatch Unit 1 Technical Specifications (TS) and to Table 3.3.2-2 of the Hatch Unit 2 TS. The requested i
i changes would revise the high room temperature setpoints for the Reactor Water Cleanup (RWCU) system.
The licensee's initial request (Reference 1) was supplemented by letter dated January 23, 1987 (Reference 2) which furnished additional infonnation in response to NRC questions.
On April 30, 1987, the licensee provided further supplemental infonnation (Reference 3). Both References 2 and 3 provided information to enable the NRC staff to better understand the licensee's request for change to the TS, but neither reference changed in any way the details of the change requested.
The Reactor Water Cleanup (RWCU) system is a non-safety related system which maintains the purity of the reactor water.
The only portion of the RWCU system that is safety related is the piping from the reactor recirculation piping up to and including the double containment isolation valves and the related instrumentation to initiate isolation. The RWCU is isolated under upset and accident conditions In order to prevent drairing the reactor vessel and to prevent dilution of the sodium pentaborate solution in the event the 4
standby liquid control system it activated. The RWCU consists, in part, of high energy piping and, thus, appropriate signals to initiate isolation in the event of a high energy line break have been provided to ensure timely i
isolation.
The Technical Specifications identify the RWCU isolation signals: high differential flow, high area temperature, and h.igh ventilation differential temperature. The licensea has requested a change only to the high area temperature setpoint.
8708120408 870810 ADOCK0500g1 DR (H
l II. EVALUATION The licensee stated in its August 25, 1986 submittal, that during the summertime, numerous spurious isolations of the RWCU have occurred-due to the receipt of a high area temperature signal. Upon investigation, there have been no leaks of reactor coolant.
Rather the high temperature signals were caused by high ambient room temperatures.
Currently, the Technical Specification Tables 3.2-1 and 3.3.2-2 for Hatch Units 1 and 2 respectively, specify a high temperature setpoint of 124 F.
In order to reduce the number of unnecessary isolations and resulting occupational doses received during investigation of the unnecessary isolations, the licensee requests a modification to these tables to specify a high temperature setpoint of 150'F.
l The Office for analysis and Evaluation of Operational Data (AE00) issued report numbered AE0D/E705 on March 31, 1987, entitled "RWCU System Automatic Isolation and Safety Consideration" (Reference 4). This report documents a review of the Licensee Event Reports (LERs) from January 1984 thro _gh October 1986 concerning RWCU isolations and has made the following conclusions.
Of all of the RWCU isolations, 74% were due to spurious signals. Slightly less l
than half of the spurious isolations were initiated by temperature signals.
Of the isolations where there was actual leakage from the RWCU pressure boundary, the usual initiating isolation signal was related to flow, not to I
area temperatures. Thus, the significant indicator for RWCU pressure boundary leakage detection is flow monitoring rather than high area J
temperature.
The licensee provided the results of an analysis of the largest leak from the I
RWCU combined with the isolation of the RWCU using the proposed increased i
temperature setpoint for isolation. The analysis demonstrated that the rate of water loss would not exceed the makeup capability of the feedwater system 1
3 and the resulting subcompartment environmental conditions would not exceed the environmental qualifications of the instrumentation required to isolate I
the RWCU system.
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l Since the equipment required for RWCU isolation (containment isolation valves and related instrumentation) is qualified for the environment to which it would be exposed (area temperatures up to 150 F) with the proposed increased temperature isolation setpoint and since the AE0D report (Reference 4) indicated that the dominant isolation signal for loss of integrity in the RWCU pressure boundary is flow related, we conclude that the increase in the 1
RWCU area temperature setpoint from 124'F to 150'F is acceptable for both Units 1 and 2.
ENVIRONMENTAL CONSIDERATION j
The amendmerts involve a change in use of facility components located within the restricted area as defined in 10 CFR Part 20. The staff has determined i
that the amendments involve no significant increase in the amounts, and no i
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significant change in the types, of any effluents that may be released offsite,
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and that there should be no significant increase in individual orTumulative i-1 occupational radiation exposure. The Commission has previously issued a d
proposed finding that the amendments involve no significant hazarcfs consideration and there has been no public comment on such finding. Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth l
in 10 CFR 951.22(c)(9).. Pursuant to 10 CFR 551.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
CONCLUSION
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The Commission made a proposed determination that the amendments involve no significant hazards consideration which was published in the Federal Register (52 FR 5855) on February 26, 1987, and consulted with the state of Georgia. No public comments were received, and the state of Georgia did not have any comments.
We have concluded, based on the considerations discussed above, that:
(1)there is reasonable assurance that the health and safety of the public will not be en-dangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Comission's regulations, and the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
References:
1.
Letter from J.T. Beckham, Georgia Power Company, to D.R. Muller, NRC, dated August 25, 1986.
2.
Letter from L.T. Gucwa, Georgia Power Company, to the NRC, dated January I
23, 1987.
3.
Letter from L.T. Gucwa, Georgia Power Company, to the NRC, dated April l
30, 1937.
4.
Report, AE0D/E705, " Engineering Evaluation Report, RWCU System Automatic Isolation and Safety Considerations," dated March 1987, prepared by the l
Office for Analysis and Evaluation of Operational Data, NRC.
Principal Contributors:
J. Ridgely L. Crocker Dated:
/ igust 10, 1987 I
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DATED August 10, 1987 i
AMENDMENT NO.144TO FACILITY OPERATING LICENSE DPR-57, EDWIN I. HATCH, UNITS 1 & 2 l
AMENDMENT NO. 79T0 FACILITY OPERATING LICENSE NPF-05, EDWIN I. HATCH,. UNITS I & 2 RISTRI m n!L:
Qocket_ File 3 o
4 NRC PDR q
Local PDR PRC System PD#II-3 Reading M. Duncan L. Crocker B. J. Youngblood D. Hagan T. Barnhart (8)
W. Jones ACRS (10) i l
OGC-Bethesda l
S. Varga/G. Lainas U. Cheh ARM /LFMB l
GPA/PA i
E. Butcher L. Reyes J. Ridgely l
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