ML20062H494
| ML20062H494 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 08/10/1982 |
| From: | Garrity J Maine Yankee |
| To: | Clark R Office of Nuclear Reactor Regulation |
| References | |
| JHG-82-149, MN-82-158, NUDOCS 8208160070 | |
| Download: ML20062H494 (3) | |
Text
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-e AJgust 10, 1982 MN-82-158 JHG-82-149 thited States NJclear Fbgulatory Commission Washington, D. C. 20555 Atteltion:
Office of NJclear Fbactor Fbgulation Division of Licensing Operating fbactors Brandi #3 Mr. Robert A. Clark, Chief Re ferences:
(a) License it. DfR-36 ([hcket 50-309)
(b) USMC Letter to MYAPCo dated May 21, 1982 (c) USmC Letter to MYAPCo dated 0:tober 22,1980 SJbject:
CONTAItNENT RJRGING Ato VENTING WFEN NOT IN A WLD SHJTDOWN OR REFUELING MODE D3ar Sir:
Reference (b) requestea obine Yankee to (1) commit to the installation of debris screens and provide a sdiedule for installation, and (2) commit to a specified annual time for venting and purging when not in a cold shutdown or refueling mode.
In addition, fbference (b) requested additional information in accordance with its Enclosure (5).
The following is the subject information requested L1 Reference (b):
DEBRIS S01EEf6 1.
Debris Screens will be installed in the containment purge supply and e>haust lines.
The screens will be seismic Category I design and be capable of withstanding a differential pressure equal to the peak containment pressure during a postulated WCA.
The spacing of the screen mesh will be similar to that given in Enclosure (3) of fbference (b).
Each screen l
will be located about one pipe diameter or greater from the inner side of l
the inboard isolation valve.
The screens will be removable to provide access to eadi inboard purge valve for maintenance.
l l
Installation of the debris screens will be done during the Q:tober,1982 Re fueling QJtage.
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PDR ADOCK 05000309 8 1 P
M AINE YANKEE ATOMIC POWER COMPANY r
thited States NJclear R!gulatory Commission AJgust 10, 1982
/ttention:
Mr. Robert A. Clark, 011ef Page two 2.
If for some unexpected reason the screens cannot be installed at that time, on-line purging will not be permitted unless the plant is in the cold shutdown, refueling shutdown or refueling operations conditions; until the installation has been completed.
TIME LIMITATION FOR ON-LINE RJRGE mine Wnkee defines on-line venting and purging as applying to that venting and purging whid1 occurs when the plant is in a condition in whidi containment integrity is required.
Ch-line purging in the containment is not normally conducted during routine operation.
Typically, on-line purging is conducted for three or four days prior to an outage when work in the containment is planned.
This type of purging is used to reduce containment activity levels so that occupational exposure rates will be low when the shutdown work is to start.
It also serves to keep rates of release of radioactive material lower than would be adileved if hitfi flow purging were instituted after shutdown.
0:casionally, on-line purging during normal operation is conducted in preparation for work to be performed in the containment while the reactor is operating, but this type of work is limited by direct radiation dose rates and is infrequent.
In either case, the extent of on-line purging in any calendar year is dependent on plant maintenance requirements.
3.
mine Wnkee will administratively limit the use of on-line purging to 300 hours0.00347 days <br />0.0833 hours <br />4.960317e-4 weeks <br />1.1415e-4 months <br /> in any calendar year.
4.
We will emplasize that on-line venting and purging should only be undertaken when there is a clear need to do so by instituting procedural controls for purging approval.
These controls will include a required justification based on a need to improve working conditions and will require approval by the plant manager.
10DITIONAL INFORMATION - 42 INCH PURE VALVES AtO 8 INCH BY-P/6S VALVE 42 INCH (DNTAIPNENT RJRE VALVES REQJEST Where operators are equipped with a manual mode of operation (e.g.
handwheels) does their desigi provide for automatic re-engagement of the automatic mode of operation following the manual mode of operation? If not, describe the procedures used to assure the valve is not left in the manual mode of operation following maintenance or test operations.
AM3WER The 42" valves are equipped with air cylinder operators for automatic or manual operation.
The valves also have handwheel operators whidi can only be used if the air operators are first
- 1ysically disconnected.
MAINE YANKEE ATOMIC POWER COMPANY a
thited States NJclear fbgulatory Comtr.ission AJgust 10, 1982 Attention:
Mr. ibbert A. Clark, Chief Page three Disconnecting the air operators is permitted only for maintenance purposes and under mine Yankee's equipment tagging rules.
The rules require that safety related equipment be functionally tested following its release for service.
REQJEST Describe the periodic maintenance and inspection programs for these valves.
ANSWER The 42 inch containment purge valves are leak tested under the Class "C" leak test program at ead refueling interval and after on-line purge.
In addition, the valve closure time is also measured at each refueling interval.
mintenanca is performed on these valves if a problem is found during these tests.
8 INCH GLDBE VALVE REQJEST The pJrge system contains an 8 Ind globe valve.
This valve is in a by-pass line around the 42 inch valve VP-A-3.
Describe the method used to show this valve is capable of closing under accident loads (e.g. seismic, LDCA, etc. )
ANSWER Prior to opening the 42" containment purge valves, the 8 ind globe valve is used only to depressurize the containment.
At other times, this valve is in the closed position.
msonellan, the valve manufacturer, has stated that the stbject valve will shut off against 55 PSI differential across the valve seat.
A portion of the manufacturer's records for this valve and the information regarding seismic capability cannot be found.
However, computer input cards are on file whid indicate that a static equivalent type seismic calculation was performed on this valve.
According to the card input, the accelerations were 2.0 g's vertical and 3.0 g's horizontal.
The static desigi conditions were 55 PSIG at 2800F.
Further details on the analysis are not available.
5.
mine Yankee will respond to your requests for surveillance technical specifications by Septenber 1,1982.
We trust that this information is satisfactory; however, should you have further questions, please contact us.
Very truly yours, MAINE YAM <EE ATOMIC POWER COMPANY
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M.h d
John r
y, Senior Director NJclea Engineering and Licensing JHG/ba
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