ML20002C590
| ML20002C590 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 02/23/1977 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20002C583 | List: |
| References | |
| NUDOCS 8101100528 | |
| Download: ML20002C590 (5) | |
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UNITED STATES f
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NUCLEAR REGULATORY COMMISSION y
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATIO SUPPORTING AMENDMENT NO.11 TO ' FACILITY '0PERATING LICENSE'N CONSUMERS' POWER COMPANY BIG ROCK POINT DOCKET NO. 50-155, INTRODUCTION By letter dated February 9,1977, Consumers Power Company (CPCo) submitted an application for a license amendment to modify the surveil-lance testing interval in the Big Rock Point Technical Specifications for the following systems: Control rod drive, liquid poison, contain-ment spray, and core spray.
DISCUSSION AND EVALUATION CPCo has requested relief from certain surveillance requirements of the Big Rock Point Technical Specifications because the testing would force the plant out of service for about a week. According to CPCo, this outage would occur during a period of high power demand and shortage of alternative power sources.
1.
Control Rod Drive System _
'he present Technical Specifications 5.2.2(a)i, ii and iii require surveil-lance testing of the Control Rod Drive System at least once every six months during periods of power operation. The surveillance tests include:
(a) checking continuous withdrawal and insertion using normal hydraulic system pressure, (b) checking latching and unlatching and functioning of the position indication system, and (c) checking the scram time of each drive.
Plant shutdown is required to perform these checks.
The latest staff regulatory guidance (NUREG-0123 Standard Technical Specifications for General Electric Boiling Water Reactors, Revision of August 15, 1976) specifies surveillance testing during each refueling outage or af ter a reactor shutdown exceeding 120 days. Also, these 8101140 D.T
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surveillance tests, currently required for plants being licensed today, are similar but less comprehensive than tests previously required on the older reactor plants such as B.ig Rock Point.
Successful testing over a three year period (the longest for which records are readily available) with no reported scram time failures, indicates that the present surveil-lance testing (every six months rather than every 18 months) is too restrictive and that testing during each refueling outage would be sufficient to assure system operability and to assure that the health and safcty of the public is adequately protected.
CPCo performed system testing on July 11, 1976, and now proposes extending the time interval by about 31/2 months or until the refueling outage scheduled to start about June 15, 1977. We agree that this short extension is acceptable and would have a negligible effect.on assurance that the rod control system will be operable as required.
Therefore, we conclude that the testing required by Specifications 5.E.2(a)i, ii, and iii may be accomplished during the next shutdown of sufficient time duration to allow such tests.
However, the testing must be accomplished prior to startup following the next refueling outage. This requirement is being added to the Technical Specifications.
2.
Liquid Poison System The present Technical Specification 5.2.3 requires test-firing of one The last squib-primer and trigger assembly at least every 12 months.
test-firing was accomplished on March 25, 1976, at Big Rock Point.
CPCo has now proposed delaying the test firing until the next refueling This proposal would outage to preclude a plant shutdown in March,1977.
extend the current test interval by about 3 1/2 months.
Our current test interval requirement for similar plants being licensed today is 18 months or about 6 months less restrictive than we have required for Big Rock Point.
The Liquid Poison System is designed with sufficient redundancy to assure operation even in the unlikely event one squib primer and trigger assembly might fail. Also, the system is a manually initiated system required only if several control rods stuck in the retracted position or when the operator must take extreme protective measures to assure the reactor is shut down.
Based on CPCo's review of records since the beginning of 1973, which revealed no reported misfires, and on the considerations noted above, we conclude that the testing of one squib primer and the trigger assembly required by Specification 5.2.3 may be accomplished during the next shutdown of sufficient time duration to allow such test-firing and that the extension of the test interval will have a negligible effect on assurance of system operability. However, the testing must be done prior to startup following the next refueling as proposed by CPCo to assure operability during the following fuel cycle. This requirement is being added to the Technical Specifications.
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3.
Core Spray System The present Technical Specifications 11.4.1.4.C and.E (Table 11.4.1.4.a) require automatic actuation of the core spray system valves and Instrument The Trip Test, including spray valve activation, once every six months.
surveillance tests involved would require a reactor shutdown. The last surveillance test for the 6 monthttime interval was performed on July 13, 1976. CPCo has now proposed delaying the surveillance test until the next refueling outage to preclude a plant shutdown in February,1977.
This proposal would extend the current test interval by about 41/2 months.
Our current test interval requirement for similar plants being licensed today is 18 months or about one year less restrictive than we have required for Big Rock Point.
By letter dated June 4,1976, we issued Amendment No.10 to the Big Rock Point Technical Specifications. A portion of this amendment modified the core spray system surveillance requirements by adding monthly testing to verify the operability of the core spray system discharge valves, ind followin'g valve actuation, to assure that the check valve between the inboard and outboard discharge valves is not stuck. Satisfactory completion of this testing in fact provides substantial assurance of proper system operation, and adequately demonstrates the operability of all system components except the sensor elements, which are redundant.
The test procedures used by the licensee to fulfill this monthly test requirement have been determined by the staff to be adequate to assure the operability of the core spray system except for the redundant sensors.
Our review of the monthly test procedures, experience to date, and the redundancy of the sensors assure us that deleting the six month automatic actuation test requirement does not result in decreasing safety margins and will not be detrimental to the health and safety of the public.
In addition, a CPCo record check since the beginning of.973 has shown no system-related malfunction which resulted in failure of the system to operate as intended.
Based on the above,...: have concluded that tests of the automatic actuation of the core spray valves required by Specification 11.4.1.4.C and.E (Table 11.4.1.4.a) may be accomplished during the next shutdown of sufficient time duration to allow such tests and that the extension of the surveillance interval will have a negligible effect on assurance of system operability. The testing must be completed prior to startup following the next iafueling. This requirement is being added to the Technical Specifications.
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4.
Containment Spray System _
Present Technical Specification 11.4.3.4.B requires biannual verification of operability of power-operated valves required for proper system Table 11.4.3.4 further specifies that instrument trip actuation.
tests including valve actuation shall be perfonned every six months.
Previous testing in accordance with these requirements was performed July 13,1976, meaning that the testing would once again be required on February 26, 1977.
The applicable current test-interval guidance of NUREG-0123, Paragraph 4.6.2.1, specifies that the drywell spray-system shall be demonstrated to be operable at least once per 5 years.
CPCo personnel performed a data search of records since the beginning of 1973 and found no reported instances of the containment spray system being found to be inoperable.
The requested extension of the test interval would involve approximately 41/2 months, but technical specifications are being.
modified to require completion of the testing prior to startup following the forthcoming refueling outage.
Because the system has been previously tested at a frequency much greater than required by present guidance, with no reported failures, and because testing will once again be_ required prior to return to power after the following refueling outage, we conclude that extending the testing interval in this case will have a negligible effect on assurance of system operability and will not be detrimental to the health and safety of the public and is therefore acceptable.
ENVIRONMENTAL CONSIDERATION We have determined that the amendment does not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant enviror, mental impact. Having made this determiration, we have further concluded that the amendment involves an action which is insignificant from tne standpoint of environmental impact and pursuant to 10 CFR 551.5(d)(4) that an environmental impact statement or negative declaration and environmental impact appraisal need not be prepared in connection with the issuance of this amendnent.
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' ! CONCLUSIONS
' We have concluded, baced on the considerations. discussed above, that:
(1) because the amencment does not involve a significant increase in the probability or consequences of accider.ts previcusly considered and does not involve a significant decrease in a sa'fety margin, the amendment
'does'not-involve a significant hazards.cor ideratica, (2) there'is reasonable assurance that the health and ::Lety of-the pablic will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in'ccmpl.iance witn the Commission's regulations and the issuance of'this amendment will.not be inimical to-the common defense and security or to the health and-safety of the
- public.
Datei February 23, 1977 t
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