ML20028F693
| ML20028F693 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 01/24/1983 |
| From: | Knighton G Office of Nuclear Reactor Regulation |
| To: | Tallman W PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| References | |
| NUDOCS 8302020500 | |
| Download: ML20028F693 (9) | |
Text
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ef DISTRIBUTION Document Control 50-443/4f /
PRC System NSIC Docket Nos.: 50-443 l
LB#3 Reading JLee LWheeler Mr. William C. Tallman Chairman and Chief Executive Officer Attorney, OELD J rdon, IE Public Service Company of New Hampshire l
Post Office Box 330 taylor, IE Manchester, New Hampshire 03105 e
,i RWright
Dear Mr. Tallman:
Subject:
Request for Information (Containment Purge and Vent Valve Operability) 4
Reference:
NRC Letter to PSNH (Kerrigan to Tallman),
Subject:
Information i
Request for Plant Site Audit for Seismic and Dynamic Review, dated October 21, 1982.
l The referenced letter forwarded three attachments containing guidance for preparing for the Seismic Qualification Review Team (SQRT) and Pump and Valve l
Operability Review Team (PVORT). site audits. Attachments 4 and 5 have naw been prepared and are forwarded herewith for your use.
Demonstration of operability of the containment purge and vent valves and the ability of these valves to close during a design basis accident and loss of coolant accident is necessary to assure containment isolation. This demon-stration of operability is required by BTP CSB 6-4 and SRP 3.10 for contain-ment purge and vent valves which are not sealed closed during operational conditions 1, 2, 3, and 4.
The Equipment Qualification Branch (EQB) is responsible for the detailed review.
>In order toestablish operability it must be shown that the valve actuator has torque capability of sufficient margin to overcome or resist the torques and/or forces (i.e., fluid dynamic, bearing, seating, friction) that resist closure of the valve when stroking from the inital open position to full seated (bubble tight) in the time limit specified. This should be predicted on the pressure (s) established in the containment following a design basis
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accident. The integrity of the valve during closure must be clearly established as well as the capability of the valve to close.
Purge vent valve structsral elements (valve / actuator assembly) must have sufficient stress margins to withstand loads imoosed while valve closes during l
a design basis accident. Torsional shear, snear, bending, tensile and compressive i
loads / stresses are considered. Once valve closure and structural integrity are assured by analysis, testing or a suitable combination, the sealing integrity after closure and long tem exposure to the containment environment must be addressed. Emphasis should be directed at the effect of radiation and of the enntainment inrev chemical calo Hane nn e==1 mata 4m1 r+km. menne+e such as the effect on sealing frem outside ambient temperatures and debris OFFICF ),.gg.. g..
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Mr. William C. Tallman Demonstration of the various aspects of operability of containment purge and vent valves may be by analysis, bench testing, insis.u testing or a combination of these means. To date we have not received a submittal from Seabrook regarding demonstration of purge and vent valve operability.
Attachments 4 and 5 are normally included with the information request for plant site audit for seismic and dynamic review. These attachments provide guidance to the applicant in responding to this request.
Questions regarding this action should be directed to the Seabrook Project Manager, Mr. L. Wheeler, 301/492-7792.
Sincerely, M
George W. Knighton, Chief Licensing Branch No. 3 Division of Licensing Attachments:
As stated cc: See next page DL: B33 DL CB W OFFICE )
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'i, S:abrook e
William C. Tallman f
Chairman and Chief Executive Officer 7
Public Service Company of New Hampshire Post Office Box 330
!%? ester, iter H= ashire 93105 cc: Thomas Dignan Esq.
E. Tupper Kinder, Esq.
John A. Ritscner, Esq.
G. Dana Bisbee, Esq.
Ropes and Gray Assistant Attorney General 225 Franklin Street Office of Attorney General Boston, Massachusetts 02110 208 State House Annex Mr. Bruce B. Beckley, Project Manager l
Public Service Company of New Hampshire Resident Inspector Post Office Box 330 Seabrook Nuclear Power Station Manchester, New Hampshire 03105 c/o US Nuclear Regulatory Commission Post Office Box 700 l
Edward J. McDermott, Esq.
Seabrook, New Hampshire 03874 1:
Sanders and McDermott 408 Lafayette Road Mr. Jchn De'.'incentis, Project Manage:
l Hampton, New Hampshire 03842 Yankee Atomic Electric Company 1671 Worcester Road Robert A. Backus, Esq.
Framingham, Massachusetts 01701 0'Niell, Backus and Spielman 116 Lowell Street itr. A. M. Ebr.er, Project Manager Manchester, New Hampshire 03105 L'nited Engineers & Constructors 30 Soutn 17?. Street its. Beverly A. Hollingworth Post Office Eox 8223 7 A Street Philadelphia, Pennsylvania 19101 Hampton Beach, New Hampshire 03842 Mr. Philip Ahrens, Esq.
Diane Curran, Esq.
Assistant Attorney General Harmon and Weiss State House, Station #6 1725 I Street,i;. W.
Augusta, Maine 04333
- 'asnington, D. C.
20006 Mr. Stephen D. Floyd Jo Ann Shotwell, Esq.
Public Service Company of New Office of the Assistan: Attorney General Hampshire Environmental Protection Division Post Office Eox 330 One Ashburton Placa Manchester, New Hampshire 03105 Boston, Massachusetts 02108 l
Seacoast Anti-Pollution League l
D. Pierre G. Cameron, Jr., Esq.
Ms. Jane Dou:nty l
General Counsel 5 Market Street i
l Public Service Company of New Hampshire Portsmouth, New Hampshi.re 03801 Post Office Box 330 Manchester, New Hampshire 03105 Mr. John B. Tanzer Town of Hampton, New Hampshire Regional Administrator - Region }
5 Morningside Drive U. S. Nuclear Regulatory Commission Hampton, NH 03842 631 Park Avenue King of Prussia, Pennsylvania 19406 Ms. Letty Hett Town of Brentwood l
RFD Dalton Road Brentwood, Ne,< Hampshire 03833 1
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I Operability Qualification of Purge and Vent Va]ves
-5 Demonstration of operability of the containment purge and vent valves i
and the ability of these valves to close during a design basis accident is necessary to assure containment isolation.
This demonstration of operability is required by Branch Technical Position (BTP). CSB 6-4 and SRP 3.10 for containment purge and vent valves which are not sealed closed during operational conditions 1, 2, 3, and 4.
1.
For each purge and vent valve covered in the scope of this review the following documentation demonstrating ccmpliance with the
" Guidelines for. Demonstration of Operability of Purge and Vent Valves (attached, Attachment #5) is to be submitted for staff review:
A:
Dynamic Torque Coefficient Test-Reports (Butterfly valves only) - including a description of the a
test setup.
B.
Operability Demonstration or In-situ Test Reports (when used)
C.
Stress Reports D.
Seismic Reports for Valve Assembly (valve andoperator) and associated parts.
E.
Sketch or description of each valve installation showing the following (Butterfly valves only):
1.
direction of ficw 2.
disc closure direction 3.
curved side of disc, upstream or downstream (asymetric discs)
- 4. -orientation and distance of elbows, tees, bends, etc.
within 20 pipe diameters of valve 5.
shaft orientation i,
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distance between valves F.
Demonstration that the maximum combined torque developed by the valve is below the actuator rating.
2.
The applicant should respond to the " Specific Valve Type Questions" (attached) which relate to his valve.
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Analysis, if used, should be supported by tests whith establish
,l torque coefficients of the valve at various angles.
As torque il coefficients in butterfly valves. are dependent on disc shape aspect ratio, angle of closure flow direction and approach flow, if these things should be accurately represented during tests.
Specifically, piping installations (upstream and downstream of I
the valve) during the test should be representative of actual field installations.
For example, non-symetric approach flow
- i from an elbow upstream of a valve can result in fluid dynamic torques f double the magnitude of those found for a valve with straight piping upstream downstream.
4.
In-situ tests, when performed on a representative valve, should be performed on a valve of each sinze/ type which is determined to represent the worst case load. Worst case flow direction, for example, should be considered.
For two valves in series where the second valve is a butterfly valve, the effect of non-symetric flow from the first valve l'
should be considered if the valves are within 15 pipe diameters
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of each other.
5.
If the applicant takes credit for closure time vs. the buildup of containment pressure, he must demonstrate that the method is con-i-
I servative with respect to the actual valve closure rate.
Actual valve closure rate is to be determined under both loaded and un-l loaded conditions and periodic inspection under technical speci-
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i fication requirements should be performed to assure closure rate I
does not increase with time or use..
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GUIDELINES FOR DEMONSTRATION M
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OF OPERABILITY OF PURGE AND VENT VALVES ~
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In order to establish operability it must be shown that the valve actuator's torque capability has sufficient margin to overcome or resist the torques and/or forces (i.e., fluid dynamic, bearing, seating, friction) that resist closure when stroking from the initial open position to full seated (bubble tight) in the time limit specified.
This should be predicted on the pressure (s) established in the con-tainment following a design basis LOCA.
Considerations which should De addressed in assuring valve design adequacy-include:
1.
Valve closure rate versus time - i.e., constant rate or other 2.
Flow direction throuh valve; AP across valve.
3.
Single valve closure (inside containment or outside containment valve) or simultaneous closure.
Establish worst case.
4.
Containment back pressure effect on closing torque margins of air operated valve which vent pilot air inside containment.
5.
Adequacy of accumulator (when used) sizing and initial charge for valve closure requirements.
6.
For valve. operators using torque limiting devices - are the settings of the devices compatible with the torques required to operate the valve during the design basis condition.
7.
The effect of the piping system (turns, branches) upstream and downstream of all valve installations.
L 8.
The effect of butterfly valve disc. and shaft orientation to the fluid mixture egressing from the containment.
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DEMONSTRATION Demonstration of the various aspects of operability of purge and vent valves may be by analysis, bench testing, insitu testing or a combination of these means.
Purge and vent valve structural elements (valve / actuator assembly) must be evaluated to have sufficient stress margins to withstand loads imposed while closes during a design basis ac'cident.
Torsional shear, shear, bending, tension and compression loads /
stresses should be considered.
Seismic. loading should be addressed.
Once valve closure and structural integrity are assured by analysis, testing or a sui. table combination a determination of the seal.ing integrity after closure and long term exposure to the containment environment should be evaluated.
Emphasis should be directed at the effect of radiation and of the containment spray chemical solutions en seal materil. Other aspects such as the effect on sealing from outside ambient, temperatures and debris should be considered.
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The following cor.siderations apply when testing is chose'n as a means t
for demonstrating valve operability:
Bench Testino A.
Bench testing can be used to demonstrate suitability of the in-l' service valve by reason of its traceability in design to a test
.l valve. The following factors should be considered when quali-fying valves through bench testing.
1.
Whether a valve was qualified by testing of an identical valve assembly or by extrapolation of data from a similarly designed valve.
2.
Whether measures were'taken to assure that pipng upstream and down stream and valve orientation are simulated.
3.
Whether the following load and environmental factors were considered a.
Simulation of LOCA b.
Seismic loading c.
Temperature soak d.
Radiation exposure e.
Chemical exposure f.
Debris B.
Bench testing of installed valves to demonstrate the suit-ability of the specific valve to perform its required function during the postulated design basis accident is acceptable.
1.
The factors listed in items A.2 and A.3 should be con-sidered when taking this approach.
In-Situ Testina In-situ testing of purge and vent valves may be performed to confirm the suitability of the valve under actual conditions. When performing such tests, the conditions (loading, environment) to which the valve (s) will be subjected during the test should simulate the design basis accident.
NOTE:
Post test valve examination should be performed to establish structural integrity of the key valve /actuatory components.
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Specific Valve Type Questions The following questions' apply to specific valve types only and need 1
to be answered only where applicable.' If not applicable, state so.
A.
Torque Due to Containment Backpressure Effect (TCB)
For those air operated valves located inside. containment, is the operator design of a type that can be affected by the containment
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prersure rise (backpressure effect) i.e., where the containment g
pressure acts to reduce the operator torque capability due to TCB. Discuss the operator design with respect to the air vent and bleeds. Show how TCB was calculated (if applicable).
4 3.
Where air operated valve assemblies use accumulators as the fail j
safe feature, describe the' accumulator air system configuration i
and its operati.on. Discuss active. electrical components in the i
accumulator system, and the basis used to determine their quali-i' system seismically designed? How is the allowable leakage from fication for the environmental conditions experienced. Is this 2
the accumulators determined and monitored?
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C.
For valve assemblies requiring a seal pressurization system (inflatable main seal), describe the air pressurization i~
system configuration and operation including means used to determine their qualification for the environmental condition experienced. Is this system seismically designed?
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D.
Where electric motor operators are used to close the valve has the minimum available voltage to the electric operator under both i
normal or emergency modes been determined and specified to the i
operator manufacturer to assure the adequacy of the operator to stroke t,he valve at accident conditions with these lower limit 3
voltages available? Does this reduce voltage operation result
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in any,significant change in stroke timing? Describe the emergency mode power source used.
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Where electric motor and air operator units are equipped I
with handwheels, does their design provide for automatic-re-engagecent of the motor operator following the handwheel mode of operation?
If not, what steps are taken to preclude i
the possibility of the valve being left in the handwheel mode following some maintenance, test etc. type operation?
l F.. For electric' motor operated valves have the torques developed during operation been found to be less than the torque limiting l
. settings?
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Specific Valve Type Questions
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The following questions ' apply to specific valve types only an'd need l
to be answered only where applicable.' If not applicable, state so.
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A.
Torque Due to Containmint Backpressure Effect (TCB)
For those air operated valves located inside. containment, is the
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operator design of a type that can be affected by the containment prersure rise (backpressure effect) i.e., where the containment
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pressure acts to reduce the operator torque capability due to TCB. Discuss the operator design with respect to the air vent and bleeds. Show how TCB was calculated (if applicable).
B.
Were air operated valve assemblies use accumulators as the fail safe feature, describe the' accumulator air system configuration and its operati.on.
Di' cuss active. electrical components in the s
accumulator system, and the basis used to determine their quali-i fication for the environmental conditions experienced. Is this system seismically designed? How is the allowable leakage from the accumulators determined and monitored?
C.
For valve assemblies requiring a seal pressurization system (inflatable main seal), describe the air pressurization system configuration and operation including means used to determine their qualification for the environmental condition experienced. Is this system seismically designed?
D.
Were electric motor operators are used to close the valve has the minimum available voltage to the electric operator under both normal or emergency modes been determined and specified to the operator manufacturer to assure the adequacy of the operator to stroke t,he valve at accident conditions with these lower limit voltages available? Does this reduce voltage operation result in any, significant change in stroke timing? Describe the emergency mode power source used.
f.
Were electric motor and air operator units are equipped with handwheels, does their design provide for automatic.
i re-engagecent of the motor operator following.the handwheel mode of operation? If not, what steps are taken to preclude i
the possibility of the valve being left in the handwheel mode following some maintenance, test etc. type operation?
F.
For electric' motor operated valves have the torques: developed during operation been found to be less than the torque limiting
. settings?
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