ML19263E648
| ML19263E648 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 04/09/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19263E649 | List: |
| References | |
| NUDOCS 7906200565 | |
| Download: ML19263E648 (3) | |
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 47 TO FACILITY LICENSE N0. DPR-39 SUPPORTING AMENDMENT NO. 44 TO FACILITY LICENSE NO. DPR-48 COMMONWEALTH EDISON COMPANY ZION STATION UNITS 1 AND 2 DOCKET NOS. 50-295 AND 50-304 Introduction By letter dated March 23, 1979, Commonwealth Edison Company (the licensee) requested a change to the Technical Specifications appended to Facility Operating Licenses DPR-39 and DPR-48 for Zion Units 1 and 2, respectively.
This change would delete the surveillance requirement for the performance of cold rod drop tests.
In considering this proposed change, we discussed certain modifications to more nearly reflect the rod drop time provision as contained in the Westinghouse Standard Technical Specifications. The licensee has agreed to these clarifying changes.
Discussion The Zion Station Technical Specifications contain a Limiting Condition for Operation (LCO) that requires that the control rod system be operable when in the hot standby or power operation modes.
There is also an LC0 and surveillance test that specifies the maximum rod drop time (1.8 seconds) for all full length control rods for operating temperature and rated reactor coolant flow conditions. There is no LC0 specified for maximum rod drop time under cold conditions.
However, there is a surveillance requirement to drop but not time the rods under cold conditions after each refueling or following maintenance that could affect performance of a control rod.
In its letter of March 23, 1979, the licensee proposes that rod drop tests under cold conditions be deleted as unnecessary.
The licensee asserts that the rod drop tests required under hot conditions are sufficient to assure the operability of the system in the required modes.
7 9 0 6 20 0 5 GS
- Evaluation We have reviewed the licensee's proposal to delete the cold rod drop tests and agree that these tests are unnecessary.
The bases for our conclusion are provided below.
The Westinghouse Standard Technical Specifications (STS) specify maximum individual rod drop times for hot conditions (Tavg >_5410F) and with all reactor coolant pumps operating. There are no rod drop tests specified for cold conditions. The STS bases state that measurement with Tavg >_5410F and with all reactor coolant pumps operating ensures that the measured drop times will be representative of insertion times experienced during a reactor trip at operating conditions.
Deletion of the requirement to conduct cold rod drop tests at Zion Station would bring the facility Technical Specification into conformance with the staff's current policy regarding rod drop tests.
The licensee believes that these cold rod drops were required initially as a precautionary measure for the initial startup of the plants.
The Zion Units were the first of the large four-loop Westinghouse plants to connence commerical operation. As indicated by the licensee, experience has shown these cold rod drop tests are no longer needed.
Since the initial startup of each unit in 1973 and 1974, there have been no significant rod malfunctions identified through the cold tod drop tests.
Since the requirement exists 'to conduct rod drop timing tests under hot conditions and at rated raactor coolant flow after each refueling and after maintenance that could affect the proper functioning of a rod, adequate assurance exists that an inoperable rod will be identified prior to any return to power operation.
Except during low power physics tests, the Zion Station Technical Specifications require that the reactor coolant temperature be greater than 5000F prior to the reactor being critical. Also, since no credit is taken in the Zion Station Final Safety Analysis Report (FSAR) for rod insertion while the reactor coolant system is in a cold condition, there is no apparent need from an accident standpoint to conduct cold rod drop tests.
Based on the above we have concluded that from a safety standpoint, there is no need for conducting cold rod drop tests.
2287 152 Environmental Consideration We have determined that the amendments do not authorize a change in effluent types or total amounts or an increase in power level and will not result in any significant environmental impact.
Having made this detennination, we have further concluded that the amendments involves an action which is insignificant from the standpoint of environmental impact and, pursuant to 10 CFR 551.5(d)(4), that an environmental statement, or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of these amendments.
Conclusion We have concluded, based on the considerations discussed above, that:
(1) because the changes do not involve a significant increase in the probability or consequences of accidents previously considered and do not involve a significant decrease in a safety margin, the changes do not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulation and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Date: April 9,1979 2287 153
7590-01 UNITED STATES NUCLEAR REGULATORY COMMISSION DOCKET NOS. 50-295 AND 50-304 COMMONWEALTH EDISON COMPANY NOTICE OF ISSUANCE OF AMENDMENTS TO FACILITY OPERATING LICENSES The U. S. Nuclear Regulatory Commission (the Comission) has issued Amendment Nos. 47 and 44 to Facility Operating License Nos.
DPR-39 and DPR-48 issued to Commonwealth Edison Company (the licensee) which revised Technical Specifications for operation of the Zion Station, Unit Nos. I and 2, located in Zion, Illinois. The amendments are effective as of the date of issuance.
These amendments delete the surveillance requirements for the perfonnance of cold rod drop tests and clarify the requirements for performance of hot rod drop tests.
The application for these amendments complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act),
and the Commission's rules and regulations. The Commission has made appropriate findings as required by the Act and the Commission's rules and regulations in 10 CFR Chapter I, which are set forth in the license amendments.
Prior public notice of these amendments was not required since the amendments do not involve a significant hazards consideration.
2287 154 Toszscsno D.
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7590-01 The Commission has determined that the issuance of these amendments will not result in any significant environmental impact and that pursuant to 10 CFR 951.5(d)(4) an environmental impact statement, or negative declaration and environmental impact appraisal need not be prepared in connection with issuance of these amendments.
For further details with respect to this action, see (1) the application for amendments dated March 23,1979,(2) Amendment Nos.
47 and 44 to License Nos. DPR-39 and DPR-48, and (3) the Commission's related Safety Evaluation. All of these items are available for public inspection at the Commission's Public Document Room,1717 H Street, N. W., Washington, D. C.
20555 and at the Zion-Benton Public Library District, 2600 Emmans Avenue, Zion, Illinoi 60099. A copy of items (2) and (3) may be obtained upon request addressed to the U. S. Nuclear Regulatory Comission, Washington, D. C.
20555, Attention: Director, Division of Operating Reactors.
Dated at Bethesda, Maryland, this 9th day of April,1979.
FOR THE NUCLEAR REGULATORY COMMISSION
!.'42Wk V A. Schwencer, Chief Operating Reactors Branch #1 Division of Operating Reactors 2287 155