ML20041F231
| ML20041F231 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 03/11/1982 |
| From: | Bordine T CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8203160310 | |
| Download: ML20041F231 (3) | |
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@ Power Consumers company Generet offkes: 212 West Mkhleen Avenue, Jackson Michigen 49201 * (517) 708 4650 March 11, 1982 apr\\\\*
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m:1 Eig et Dennis M Crutchfield, Chief Operating Reactors Branch No 5 b
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&ggh Nuclear Reactor Regulation 6
US Nuclear Regulatory Commission W
Washington, DC 20555 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLANT - TECHNICAL SPECIFICATION INTERPRETATION OF SECTION 3.7(c)
This Technical Specification Interpretation of Section 3.7.(c) is provided in response to concerns raised by the NRC Site Resident Inspector, Mr G Wright, regarding the performance of leak check versus leak rate testing on calibra-tion test connections associated with containment pressure instrumentation.
The specific concern is associated with removal / replacement of one-half inch or less pipe caps to test connections. The applicable technical specification paragraphs of section 3.7(c) are as follows:
The probable cause of any significant corrosion, cracking or deterioration revealed by such visual examination shall be determined, and evaluated in terms of likelihood of recurrence and probable effect upon other contain-ment sphere penetration components. An individual component leak detec-tion test shall be performed with air at 10 psig on the faulty component prior to its repair or modification. The faulty component, and other components if necessary, shall be repaired or modified, and an individual component leak detection test performed with air at 10 psig upon each repaired or modified component. All components so repaired or modified shall be visually reexamined at appropriate intervals, but not less frequently than once every six conths, until the adequacy of annual visual inspection is reestablished to the operator's satisfaction.
After cutting into the sphere or its components, or any disassembly of Io01 components that would affect sphere integrity, an individual component j l5 leakage rate or an integrated leakage rate test, whichever is deemed more appropriate by the operator, shall be performed, with air at a pressure fg not less than 10 psig.
It shall be permissible to employ a leak detection test in lieu of the above for insuring containment integrity following oc0382-0006bl42 8203160310 820311 PDR ADOCK 05000155 P
d D M Crutchfield, Chief 2
Big Rock Point Plant Tech Spec Interpretation of Sec 3.7.(c)
March 11, 1982 disasembly of the emergency condenser or the gasketed, bolted closure of the coaxial cable electrical penetrations.
The above first paragraph applies to leak check or leak detection tests. A leak check or leak detection test consists of a snoop or soap bubble test under 10 psig. The leak check is performed "upon each repaired or modified component."
The above second paragraph primarily addresses leak rate tests, however, a leak check is permissable for certain components. A component leak rate test consists of observing pressure decay from an initial pressurization of 27 psig. The leak rate test is performed after cutting or " disassembly of components that would affect sphere integrity".
It is apparent that a pipe cap removal / replacement, if considered disassembly to a component, requires a subsequent leak rate test should the component have the potential of affecting sphere integrity.
It is the position of Consumers Power Company that removal of a pipe cap is not disassembly of piping or of e component. A pipe cap's function is to provide controlled access to the inside of the piping. This practice is consistent with ANSI /ISA S67.01 (approved February 19, 1981, titled, " Transducer and Transmitter Installation for Nuclear Safety Applications", Step 8.2.5.2 quoted below:
8.2.5.2 Calibration Test Connections
" Connections provided at or near the transducer for the use of portable test and calibration equipment shall be provided with a plugged or capped connection designed for repeated assembly and disassembly."
The characteristic of a pipe cap is essentially identical to that of a valve.
That is, a pipe cap is designed for many openings and closings. Furthermore, it is not readily apparent why a leak check is considered a requirement since a pipe cap exhibits the same shutoff characteristics of a valve. Consumers Power Company has performed and will continue to perform leak checks on all containment building pressure signal lines at Big Rock Point Plant following calibration. This practice is consistent with our intent to assure zero leakage.
The resident inspector, as alternatives to the performance of a local leak rate test, has suggested either the installation of an additional isolation valve with the cap or the installation of two isolation valves. These alternatives are equivalent to a boiler code boundary for the nuclear steam supply system.
It is the position of Consumers Power Company that installa-tion of these additional valves would not eliminate the necessity for the performance of a leak check. Establishing a boiler code boundary on an instrument calibration test connection deviates from accepted power plant practices and would provide a boundary no more dependable than the test cap; le, if the test valve were to leak (or was not tightly closed), leakage from oc0382-0006bl42
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s' D M Crutchfield, Chief 3
Big Rock Point Plant Tech Spec Interpretation of Sec 3.7.(c)
March 11, 1982 the outer valve boundary (valve packing, etc) is still possible if a leak check is not performed.
In addition, installation of various test tap valves
(<*15) to perform the leak rate test would increase the possibility of a valving error. The severity of this newly created problem far outweighs the impact of performing a leak check on the pipe caps.
Therefore, Consumers Power Company will employ the leak check method on applicable calibration test connections external to containment.
It is our position that this method is consistent with section 3.7(c) of the Big Rock Point Plant Technical Specifications.
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,c Al, Thomas C Bordine Staff Licensing Engineer CC Administrator, Region III, USNRC NRC Resident Inspector-Big Rock Point i
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