ML20002C658
| ML20002C658 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 03/28/1972 |
| From: | Skovholt D US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Sewell R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| Shared Package | |
| ML20002C659 | List: |
| References | |
| NUDOCS 8101100675 | |
| Download: ML20002C658 (3) | |
Text
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,YAF i 1972 Dociet No. 50-155 Consumrs Power Company ATTN.
Mr. Ralph B. Sewell Nuclear Licensing Administrator 212 West Michigan Avenue Jackson, Michigan 49201 Gestlemen.
We have reviwed the information concerning " Inservice inspection of Nuclear Reactor Coolant Systems" presented by your letter dated September 29, 1971, and " Primary Coolant Pressure Boundary Laak Detection
- presented by your letters dated September 11, 1970, and Septanbar 29, 1971.
Tae inservice inspection program submitted by your Septer:bar 29, 1971 letter lists numerous exceptions to tne ASIE Boiler and Pressure Vessel Code - Section XI dated January 1,1970, but does not list the items to be inspected, the inspection methods or the frequency of inspections in a format suitable for inclusion in the Technical Specifications for the Big Rock Point reactor. Such a list should be prepared and submitted as a proposed change to the Technical Specificationa prior to April 21,1972.
As noted in your September 29, 1971 letter, the present Technical Specifications for Big Rock Point do not include allowable leakage rates pursuant to the AEC's interim Acceptance Criteria for Emergency Core Cooling Systems. In view of the large number of exceptions to the ASE Boiler and Pressure Vessel Code laservice inspection Require-meats, we have concluded that leak detection capability must be assessed quantitatively and suitable limits proposed for the Tech-nical Specifications by July 1,1972.
The following additional information is required to assess the adequacy of the reactor coolant leak detection system technical spegification changes tnat you are requested to submit, a""
P00R ORIGINALS no
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1 sg Consumers Power Company MAR 2 81972 1.
_ Containment Venti _1_ation Provide a description of the containment ventilation system, including; 1.1 volumetric flow rates at the fresh air intake, the contain-ment exhaust and ventilation ducts to the rasctor vessel compartment, recirculation pump room, control rod drive room, and steam drum cavity, 1.2 free voltaes of primary system enclosures or air transport times through tne various enclosures; 1.3 temperature and humidity equipment and controls.
2.
Primary Coolant _ Leakage Sensors _
Considering air transport time, steam-particulate-air mixing, ventilation variables, location of Icak, and primary coolant radioactivity:
2.1 describe the operation of the dew cell in the exhaust of the steau drum cavity a.3d identify the overall response time and sensitivity for detecting primary coolant leakage; 2.2 describe leak confirmation procedures and leak detection sensitivity based on air particulate activity measure-ments of a grab sample from the steam drum cavity; 2.3 justify relocation of the dew cell described above from the exhaust of the steam drus cavity to the exnaust from the recirculation pump room, 2.4 describe the leak detection capability of the continuous air reduction sonitor that is to be installed at the Big Rock Point plant to sample air being discharged from the containment, i
2.5 describe the leak detection capability of the containment condensate collection system with respect to time to detect leakage and sensitivity of leak detecti-
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MAR 2 81972 Consumers Power Company
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3.
Feasibility of_ Leak Detection Sensitivity Tests Discuss the feasibility of performing leak detection sensitivity tests with controlled releases of primary coolant and steam at selected locations within the Big Rock Point plant to simulate anall primary system coolant leaks and assess the adequacy of the leak detection capability provided at the plant.
4.
Primary Sys_ tem Breaks Below Core illustrate by typical exa:nples for a range of coolant activities the size and location of leaks that can be detected and the time to detect such leaks using the various sensors existing or to be provided at the Big Rock Point plant.
5.
Normal Primart Coolant Leakage During normal operation, limited coolant Icakage from pump seals, control rods, valve packing. etc., is expected.
Discuss the means for measuring this leakaEe and the effect of this background leakage on early detection of leaks from small primary coolant system cracks.
Simecrely, v5 Donald J. Skovholt Assistant Director for Reactor Operations Division of Reactor Licensing ec.
George F. Trowbridge, Esquire Distribution Shaw, Pittman, Potts, Trowbridge & Madden PDR 910 - 17th Street, N. W.
Docket File Washington, D. C.
20006 OGC (2)
C6mpliance (2)
ACRS (16)
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