ML20008F329
| ML20008F329 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 03/03/1981 |
| From: | Ippolito T Office of Nuclear Reactor Regulation |
| To: | Pilant J NEBRASKA PUBLIC POWER DISTRICT |
| References | |
| NUDOCS 8103120835 | |
| Download: ML20008F329 (5) | |
Text
0
((
o,,
UNITED STATES NUCLEAR REGULATORY COMMISSION 3
o E
WASHINGTON, D. C. 20555
\\h....w.
March 3,1981 18)[,N Docket No. 50-298
/
.\\
[
Mr. J. M. Pilant, Dimetor O
- 4/i'g _ /Sg/ A Licensing and Quality Assurance d
1(j^
Nebraska Public Power District 3/
- %r j d/
P. O. Box 499 Colunbus, Nebraska 68501 A/
A' zig' -Q's
Dear Mr. Pilant:
Your letter of Decenter 18, 1979 corrnitted Nebraska Public Power District to operate Cooper Nuclear Station in conformance with the staff's interim position related to containment purge and vent valve operability. The staff in conhnction with Brookhaven National Laboratory has reviewed your submittal. As part :
this myiew your response has been evaluated to determine its applicability to satisfy the long term operability requirements for the purge and unt valves identified in the staff's September 27, 1979 letter.
Based on this review it has been determined that additional in#ormation is required before the long term operability review can be completed. contains questions related to operability of the air and motor operated purge and vent valves which you are requested to respond to within 60 days of receipt of this letter.
Sincerely, l
e g.4 Thomas
' ppoTito, Chief Operating Reactors Branch !2 Division of Licensing
Enclosures:
- 1. Questions cc:
V. Noonan C. Haughney E. Reeves
-81031201i35
~
3 l
.=.
Mr. J..M. Pilant Nebraska Public Power District 2_
Mbrch 3,1981 cc:
~Mr. G. D. Watson, General Counsel Nebraska Public Power District P. O. Box 499 Columbus Nebraska 68601 Mr. Arthur'C. Gehr, Attorney Snell & Wilmer 3100 Valley Center Phoenix, Arizona _ 85073
. Cooper Nuclear Station ATTN: Mr. L. Lessor Station Superintendent P. O. Box 98 Brownville, Nebraska 68321 Auburn Public Library 118 - 15th Street Auburn, Nebraska 68305 Mr. Dennis Dubois USNRC Resicent Inspector P. O. Box d46 Nebraska City, NA 68410 O
e S
6 e
4
=
e
ENCI.05URE 1 REQUEST FOR ADDITIONAL INFORFATION COOPER NUCLEAR GENEPATING STATION CONTAINMEhi PURGING DURING NORMAL PLANT OPEPATION t,
MECHANICAL OPE?ASILITY DEMONSTRATION 1.
AIR OPERATED VALVES 237AY,'233AY, 245AV, AND 246A Was the Allis Cha'1cer's (AC) test report A-C, VER-0209 used as the 1.1 a.
basis fo. predicting valve loading results from the CSA-1.0CA post- ~
ulatedt
~
b.
k' hat test numbers in the AC report apply to these valves? ~
c, Was the peak containment pressure resulting from the D3A-LOCA used for the " Initial Upstrea Pressure" (as used in the AC report)? If not, provide the rationale used to allow use of a lower " Initial Up-stream Pressure." Discuss instrument lag times used, actual valve closure tices or Tech. Spec. allowable times as they apply.
1.2 Vnat were identified as the critical parts-in these valves (shaft, disc to shaft pins, other)? khat were the stresses calculated? Do they include simultaneous seisnic loading? Ynat are the design allewable stresses? What code or standards are the valves destgr.ed to?
1.3 Do the operators have caximum t rque rating (s) as established by the r.anufacturer? Rw does it cc pare to the maximum tercue developed dur-
' ng the accident postulated? Does combined loading of spring and i
dynamic t0rque affect any parts of the cperator to the extent that they be:::e the limiting factor?
1.4 Is there sufficient torque margin available from the 0;erator to over-come the torques developed that tend to c; pose valve closure as the valve strckes frcs its initial open position to the fully seated posi-tion.
What is the minicum cargin available and at what disc angle does this minicum exist?
1.5 For those valve asseablies (with air operators) inside containment, has the containment pressure rise (backpressure) been considered as to its affect on torque margins available'(to close and seat the valve) from the actuator? During the closure period, air cust be vented from the actuators opening side through the solenoid valve into this backpres-sure. Discuss the installed actuator bleed configuration and provide basis for not considering this backpressure affect a problem on torque margin.
Yalve assembly using 4 way solenoid valve should especially be reviewed.
1.5 Describe the extent to which the valve assembly (valve and operator) is seismically qualified?
1.7 Describe the extent to which_ the pilot solenoid valves are seismically qualified and enviren=entally qualified for long term exposure to the nornal plant environ = eat.
If the purce valves are to be operative post-LOCA describe the extent to which the solencid valves are environ-centa11y qualified for the.LCCA environ =ent.
Do the elasto=eric parts, solenoids, etc. have a qualified design life where periodic replacecent-of parts is required?
o, e
1.8 Describe the extent to which.the operators are 'seismica11y qualified and environmentally qualified for long term exposure to the normal plant en-vironment? If the purge valves are to be operative post-LOCA,' describe ~
the extent to which the operators are environmentally qualified for the -
LOCA environment.
Do.the elastomeric parts in the operator have a qual-ified design life where periodic replacement,is require t?
1.9 Do the elastomeric parts in the valve body have a qualifi3d design. life?
Are they required to be replaced periodically?
~
1.10 Have the manufacturer's recommended preventive maintenrice instructions
-(lubrication, etc.) been reviewed for the valve, operator and solenoids and are they being followed?
1.11 Where air operated valve assemblies use accumulators as the fail-safe feature, describe the accu =ulator air system configuration and its oper-ation.
Provide necessary information to shcw the. adequacy of the accu- "
mulator to stroke the valve i.e., sizing and operation starting from~
lower limits of initial air. pressure charge. Discuss active electrical, components in the accumulator system, and the basis used to determine their qualification for the environmental conditions experienced.
1.12 Provide an assessment of the structural capability of any ducting or
--piping in the purge system which is upstream or downstream of the, valves and is exposed to the flow condition associated with the LOCA and the seismic event. The staff is particularly interested in the effects that loose debris frca the pipe or duct systen may have on the closure ca;a-bility of these valves.
2.
MOTOR OPERATED VALVES 230MV, 231R/, 232MV, ;ND 233MV 2.1 Same as Question 1.1 a, b, and c.
2.2 Same as Question 1.2.
2.3 What are the maximum torque ratings of the operators.
How do they ccm-pare to the torques developed during the DBA-LOCA postulated?
2.4 Same as Question 1.4.
2.5 Has the m'inimum available voltage to the electric o'perator under both normal or emergency modes been determined and'speci.fied to the operator manufacturer, to assure the adequacy of the operator to stroke the valve at DBA conditions with these lower limit voltages available. Does this reduced voltage operation result in any significant change in stroke timing?
2.6 Same as Question 1.6.
2.7 Same as Question 1.8.
2.8 Same as Question 1.9.
e awe
.5 2.9 Same as Question 1.10.
l 2.10 Have the manufacturers recommended' preventive maintenance instructions (lubrication, etc.) been reviewed for the valves and operators and are they being followed?
~
~
2.11 Same as Question 1.12.'
~
e e
I O
e
=
I 5
e a
e as 6
O