ML19331B825
| ML19331B825 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 07/16/1980 |
| From: | Novak T Office of Nuclear Reactor Regulation |
| To: | Clayton F ALABAMA POWER CO. |
| References | |
| NUDOCS 8008130278 | |
| Download: ML19331B825 (4) | |
Text
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o, UNITED STATES I
NUCLEAR REGULATORY COMMISSION i-I wasumorou, o. c. 2osss o
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July 16,1980 Docket No. 50-348 Mr. F. L. Clayton, Jr.
Senior Vice President Alabama Power Company Post Office Box 2641 Birmingham, Alabama 35291
Dear Mr. Clayton:
We are continuing our review of the generic issue on containment purging and venting.
In your letter of December 10, 1979 in response to our October 23,1979. request for your commitment to the " Interim Position" you provided an analysis of the 18-inch mini-purge valves. Subsequently, by letter dated January 15, 1980 you committed to block the 18-inch mini-purge valves to open no greater than 50 degrees on an interim basis until the NRC review is completed. Thus, we confirm your commitment and agree that it remain effective pending completion of our long-term review of this generic issue.
We have reviewed your submittals against our " Guidelines for Demonstration of Operability of Purge and Vent Valves" provided in our September 17, 1979 letter to all licensees. Before we can complete our review, additional infonnation as indicated in the enclosure is necessary. We request your response within 45 days of receipt of this letter.
Sincerely, Thomas M. Novak, Assistant Director for Operating Reactors Division of Licensing
Enclosure:
Request for Additional Information cc: w/ enclosure See next page 8008130 2 7 7
o km Mr. F. L. Clayton, Jr.
Alabtaa Power Conpany
-:2;-
July 16, 1980 cc: Alan R. Barton Executive Vice President Alabama Power Conpany Post Office Box 2641.
Birmingham, Alabama 35291 Ruble A. Thomas, Vice President Southern Conpany Services, Inc.
Post Office Box 2625 Birmingham, Alabama 35202 George F. Trowbridge, Esquire Shaw, Pittman, Potts and Trowbridge 1800 M Street, N.W.
Washington, D. C.
20036 Mr. Robert A. Buettner, Esquire Balch, Bingham, Baker, Hawthorne, Willians and Ward Post Office Box 306 Birmingham, Alabana 35201 Edward H. Keiler, Esquire Keiler and Suckley 9047 Jefferson Highway River Ridge, Louisiana 70123 George S. Houston Memorial Library 212 W. Burdeshaw Street Dothan, Alabama 36303
Demonstration of Operability of Purge and Vent Valves Request for Information For 18.0 Inch and 48.0 Inch Purge Valves 1.
The AP across the valve is in part predicated on the containment pressure and gas density conditions. What were the containment conditions used to determine the AP's across the valve at the incremental angle positions during the closure cycle?
2.
Were the dynamic torque coefficients used for the detennination of torques developed, based on data resulting from actual flow tests conducted on the particular disc shape / design / size? What was the basis used to predict torques developed in valve sizes different (especially 1.arger valves) than the sizes known to have undergone flow tests?
3.
Were installation effects accounted for in the detennination of dynamic torques developed? Dynamic torques are known to be affected for example, by flow direction through valves with off-set discs, by downstream piping backpressure, by shaft orientation relative to elbows, etc.
What was the basis (test data or other) used to predict dynamic torques for the particular valve installation?
4.
When comparing the containment pressure response profile against the valve position at a given instant of time, was the valve closure rate vs. time (i.e. constant or other) taken into account? For air operated valves equipped with spring return operators, has the lag time from the time the valve receives a signal to the time the valve starts to stroke been ac-counted for?
Note: Where a butterfly valve assembly is equipped with spring to close air operators (cylinder, diaphragm, etc.), there typically is a lag time from the time the isolation signal is received (solenoid valve usually de-energized) to the time the operator starts to move the valve.
In the case of an air cylinder, the pilot air on the opening side of the cylinder is aproximately 90 psig when the valve is open, and the spring force avail-able may not start to move the piston until the air on this opening side is vented (solenoid valve de-energizes) below about 65 psig, thus the lag time.
5.
Provide the necessary infonnation for the table shown below for valve positions from the initial open position to the seated position (10' increments if practical).
Valve Position (in degrees - 90*
= full open)
(across valve)
(capability) 6.
What Code, standards or other criteria, was the valve designed to? What are the stress allowables (tension, shear, torsion, etc.) used for criti-cal elenents such as disc, pins, shaft yoke, etc. in the valve assembly?
What load combinations were used?
-9 p.
7
Eor those valve assemblies (with air operators) inside contaiment, has the containment pressure rise (backpressure) been considered as to its 7.
effect on torque margins available (to close and seat the valve) 'from the During the closure period, air must be vented from the actuator?
actuators opening side through the solenoid valve into this backpressure.
Discuss the' installed actuator bleed configuration and provide basis for not considering this backpressure effect a problem on torque margin.
Valve assembly using 4 way solenoid valve should especially be reviewed.
For valve assemblies requiring a ssal pressurization system (inflatable
. main seal), describe the air pressurization system configuration and 8.
operation including means used to determine that valve clos pressurization have.taken place.
this system, and the basis used to determine their qualification for the environmental condition experienced.
Is this system seismically de-signed.
For*this type valve, has it been determined that the " valve travel stops" (closed position) are capable of withstanding the loads imposed at closure during the DBA-LOCA conditions.
Where it is proposed to limit the opening angle of the butterfly valve; describe the modification made to the valve assembly to limit the opening 9.
With this modification, is there sufficient torque margin avail-able from the operator to overcome any dynamic torques developed that angle?
tend to oppose valve closure, starting from the valve's initial open Is there sufficient torque marain available from the operator position?
to fully seat the valve? Consider seating torques required with seats 5
that have been at low ambient temperatures.
Does the maximum torque developed by the valve during closure exceed the Could this affect operability?
10.
maximum t'brque rating of the operators?
Describe the tests and/or analysis performed to establish the qualifica-tion of the valve to perform its intended function under the en-11.
vironmental conditions exposed to during and after the DBA following its long term exposure to the normal plant environment.
What basis is used to establish the qualification of the valve, oper-H 12.
ators, solenoids, valves?
seismically qualified (test, analysis, etc.)?
I Where testing was accomplished, describe the type tests performed con-Tests (where applicable such as flow tests, aging 13.
ditions used etc.
simulation (thermal, radiation, wear, vibration. endurance, seismic)
LOCA-0BA environment (radiation, steam, chemicals) should be pointed out.
Where analysis. was used, provide the rationale used to reach the dec Discuss conditions, as-14.
that analysis could be used in lieu of testing.
sumptions, other test data, handbook data, and classical problems as they may apply.
,Have the preventive maintenance instructions (part replacement, lubrica-15.
tion, periodic cycling, etc.) established by the manufacturer been re-viewed, and are they being followed? Consideration should especially be given to elastomeric components in valve body, operators, solenoids c tc.
e where this hardware is installed inside containment.
2 N.m.
A n.
15 m
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