ML20205K011
| ML20205K011 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 03/24/1987 |
| From: | COMMONWEALTH EDISON CO. |
| To: | |
| Shared Package | |
| ML20205J962 | List: |
| References | |
| 2834K, NUDOCS 8704010488 | |
| Download: ML20205K011 (5) | |
Text
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ATTAOSENT A PROPOSED CHANGE TO APPENDIX A, TECHNICAL SPECIFICATIONS, FACILITY OPERATING LICENSES NPP-37 AND NPP-66 1
Revised Page: 3/4 7-13 2834K 8704010488 870324 PDR ADOCK 05000454 P PDR
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. PLANT SYSTEMS 3/4.7.5 ULTINATE HEAT SINK LIMITING CONDITION FOR OPERATION 3.7.5 Two independent ultimate heat sinks (UHS) cooling towers shall be OPERA 8LE, each with
- a. A minimum water level in the UHS cooling tower basin of 873.75 feet Mean Sea Level (MSL) (50%),
- b. With only Unit 1 operating, fans OA, 08, OE, and 0F are required to be OPERABLE. With only Unit 2 operating, fans OC, 00, OG, and OH are required to be OPERABLE. With both Units 1 and 2 operating, 3 fans with power supplied from each unit are required to be OPERA 8LE (total of 6 fans),
- c. One OPERABLE essential service water makeup pump per train, u
- d. An essential service water pump discharge temperature of less than or equal to 80*F with less than 4 fans running in high speed; or less than or equal to 98'F with all 4 fans running in high speed,
- e. A minimum Rock River water level at or above 670.6 feet MSL, USGS datum, at the river screenhouse, and
- f. Two OPERABLE deep wells with:
(1) Rock River water level forecast by National Weather Service to exceed 702.0 feet MSL, or (2) Rock River water level at or below 670.6 feet MSL, or (3) Tornado watch issued by National Weather Service that includes Byron site area.
APPLICABILITY: MODES 1, 2, 3, and 4 ACTION:
- a. With a water level of less than 873.75 feet MSL (50%) in either UHS cooling tower basin, restore the water level to 873.75 feet MSL in each UHS cooling tower basin within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> or be in HOT STANOBY with-in the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTOOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />,
- b. With one of the fans contained in the applicable combination listed above inoperable, restore the listed fans to OPERABLE status 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 HOT STANOBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and COLD SHUT 00WN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
- c. With one essential service water makeup pump inoperable, restore the essential service water makeup pump to OPERABLE status 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 HOT STAN0BY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTOOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
1 i UHS coch I No fans are.
the repred essenhui ho wev er,Wh or ejuGI to 98'F~.
b ser me.be. runnin3 watc< pu durhndi schonJc.
Ecuer per 4dn f-conana +csherahlre. must be 1
at les.3 8YRON - UNITS 1 & 2 3/4 7-13 Amendment No. 5
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I ATTAC19ENT B i EXPLANATION OF PROPOSED TECHNICAL SPECIFICATION CHANGE i
i For the purpose of performance testing the Byron essential service water cooling towers, a change is proposed to Technical Specification 3/4.7.5.
l Technical Specification 3/4.7.5d requires four cooling tower fans to be running in high speed when the essential service water pump discharge temperature is l greater than 80*F. During performance testing of the essential service water cooling towers, this proposed amendment would allow plant operation with the essential service water pump discharge temperature greater than 80*F, but less than 98*F with no cooling tower fans running. Operation in this condition is necesssary to achieve conditions in the essential service water system such that conclusive test data can be obtained. The cooling tower test program is scheduled to continue through the summer to refine the tower performance estimate. Upon completion of the test program, a report containing the results will be available for NRC review.
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l ATTACHMENT C j l
EVALUATION OF SIGNIFICANT HAZARDS CONSIDERATIONS Commonwealth Edison has evaluated this proposed amendment and determined that it involves no significant hazards considerations. According to 10 CPR 50.92(c), a proposed amendment to an operating license involves no significant hazards considerations if operation of the facility in accordance with the proposed 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 previously evaluated; or (3) Involve a significant reduction in a margin of safety.
This proposed amendment involves temporary operation of the essential service water (ESW) system with the ESW pump discharge temperature greater than 80*F and no cooling tower fans running. The limiting previously evaluated accident which is dependent upon ultimate heat sink cooling is a large break loss of coolant accident with' loss of offsite power. The probability of occurrence of a large break loss of coolant accident with loss of offsite power is not affected by operation of ESW cooling tower fans.
The consequences of a large break loss of coolant accident with loss of offsite power will not be significantly increased by operating the ESW system with ESW pump discharge temperature greater than 80*F and no cooling tower fans running. This is because the heat removal capability of the cooling towers will not be reduced by not placing all four fans in operation at the time the ESW pump discitarge temperature exceeds 80*F. It is not necessary to start all four fans when the water reaches 80*F during the cooling tower performance testing because operators involved with conducting this test will continually be aware of ESW temperature during the test.
Cooling tower fans will be energized as necessary to avoid exceeding 98'F.
In any event, Technical Specification 3/4 7.5 would require a reactor shutdown if 98'F is exceeded.
4 Operation of the plant in accordance with this proposed amendment will not change the design of the ESW system. Operation of the ESW system will remain within original design limits during performance testing of the cooling towers. Other systems which depend on ESW cooling will not be affected. Consequently, performance of the cooling tower testing with an ESW pump discharge temperature greater than 80*F and no fans running will not create the possibility of a new or different kind of accident.
The capability of the ESW system to remove heat will not be affected by operation of the system in accordance with the proposed amendment. As long as the cooling tower fans are started prior to reaching 98'F, the temperature limit of 98'F will not be exceeded. Therefore, the margin of safety has not been significantly reduced.
Based on the foregoing reasons, commonwealth Edison believes this proposed amendment involves no significant hazards considerations.
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