ML18047A484
| ML18047A484 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 07/29/1982 |
| From: | Reynolds J CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | |
| Shared Package | |
| ML18047A483 | List: |
| References | |
| TASK-05-11.A, TASK-5-11.A, TASK-RR NUDOCS 8208020304 | |
| Download: ML18047A484 (2) | |
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CONSUMERS POWER COMPANY Docket 50-255 Request for Change to the Technical Specifications License DPR-20
. For the reasons hereinafter set forth, it is requested that the Technical Specifications contained in. the Provisional Operating License DPR-20, Docket 50-255, issued to Consumers Power Company on October 16, 1972, for the Palisades Plant be changed as described in Section I below:
I.
CHANGES A.
Add a new section 4.3.j to read as follows:
"4. 3. j Following each use of the LPSI system for shut.down cooling, the reactor shall not be made critical until the LPSI check valves (CK-3103, CK-3118, CK-3133 and CK-3148) have been verified closed."
B.
Add to the Basis of Section 4.3:
"Valves Testing To ensure the continued integrity of selected check valves which are relied upon to preclude a potential LOCA outside containment, specia~ requirements for periodic leak tests are specified.
In addition a valve disk position check for the LPSI check valves is specified following each use of the LPSI system for shutdown cooling.
This position check ensures that the four LPSI check valves have reclosed upon.cessation of shutdown cooling flow."
NOTE:
Revised Technical Specification pages are attached.
Proposed char.ges are shown by a vertical line in the right-hand margin.
II.
DISCUSSION In the design of the Palisades safety injection systems a source of
- water from each subsystem (High Pressure Safety Injection (HPSI),
Low Pressure Safety Injection (LPSI) and Redundant High Pressure Safety Injection) combines into a common injection line which feeds one primary coolant system cold leg.
This arrangement is repeated such that a separate line supplies each of the four cold legs with each line in turn being supplied from all three subsystems.
Twelve motor-operated valves, each in series with a check valve, are provided to isolate each of the three safety injection subsystems supplies to each of the four injection lines.
Upon receipt of a Safety Injection Signal, all twelve motor-operated valves open automatically and pumps start so that each of the four injection lines has water available from all three sources to each line. If an LPSI check valve were open in this condition and primary coolant system pressure remained relatively high (e.g. during a small break LOCA), HPSI pump discharge pressure could be imposed on LPSI piping, thereby causing LPSI design pressure to be exceeded.
( 8208020304 8207 29 I
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D M Crutchfield, Chief Pali sades Plant Request for Change to the Tech Specs July 29, 1982 II.
DISCUSSION (Can't)
System design normally prevents this situation from occurring.
The LPSI check valves are closed whenever the primary coolant system is above approximately 300 psi.
These valves would only be opened by flow during shutdown cooling and when the large LPSI flow volume is needed rapidly during a large break LOCA.
During other conditions a reverse differential pressure would normally exist to.hold the valves closed.
This system configuration was reviewed extensively under Systematic Evaluation Program Topic V-11.A.
The review concluded that specific assurance of check valve closure would be desirable following each 2
use of the LPSI system for shutdown cooling.
As agreed by Consumers Power Company, plant operating procedures are being modified to incorporate this provision.
This proposed change to Technical Speci-fications is essentially a pro forma change to formalize this po~ition.
III.
CONCLUSION Based on the foregoing, both the Palisades Plant Review Committee and the Safety and Audit Review B.oard have reviewed these changes and find them acceptable.
CONSUMERS POWER COMPANY B~
.J W Reynolds, Executive Vice President, Energy Supply Sworn and subscribed to before me this 29th day of July 1982.
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Helen I Dempski, Nata~~
Jackson County, Michigan My commission expires December 14, 1983.
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