ML17174A156
| ML17174A156 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities  |
| Issue date: | 10/22/1979 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Peoples D COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 7911160568 | |
| Download: ML17174A156 (5) | |
Text
Distribution Docket Nos. 50-;491 50..:254 50-265
~ocket.,
ORB #3 and Mr. o. Louis Peoples Director of Nuclear' Licensing Commonweal th Edi son C_ompany NRR Reading Local PDR.
NRC PDR Tippol ito ERee_ves
. Atty,* OELD OI&E (3).
TERA P. 0. Box 767 A.CRS-- ( 16 )
Chicago, Illinois 60690 SSheppard RBevan
Dear Mr. People~:
RE:
Containment,Purging and Venting During Nornial Operation By letter dated November 29, -1978, the Commission (NRC) 1requested.all licensees ()f operating reactors to respond to generic coneerns ab*out containment purging i>r venting during n9rmal plant operation *. The generic concerns were b1ofo 1 d:
( l)
(2)
Events.had 6ccurred where licensees overrode or bypassed.the saf~ty
. actuation isolat_ion signals to the cQntainment isoration valves *.
- These events ~'!ere determined to be abnonnal occurrences and reported to Co.ng_ress in January 1979. _
Recent 1 icensing,reviews have required* test? or analyses to. show that.
containment purge or vent valves would shut without degrading ~on-
. tairirnent integrity during the. dynamic lo'ads of a design basis 1 oss of cool ant accident (DBA-lOCA).
.The.NRC positiori-o*fthe November 1978.letter requested that licensees
_take the following positive actions pendfng completion *of the NRC review; (1) prohibit the override or bypass of any safety 'actuation signal Which would affect another *safety actuatio*n signal;.the NRC Office of. Inspection and Enforcement would verify that a~ministrative controls prevent.improper manual defeat of safety actuation sign.al s, and {2) cease purging (or
. venting) of containment or,limit purging (.;>r venting) to an absolute min1mum, not to.exceed 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br /> per year.
L ic~nsees t-1ere requested I to demonstrate (by test or by test and analysis) that containment isolatio_n,.
valves would -shut.under postulated OBA-LOCA condition. The. NR.C positions were amplified by citation (an9 an attached copy) of our Standard Review Plan (SRP.) 6.2.4 Revision 1 and the associated Branch Technical Position CSB 6-4, whic~ have effectively classed the purge and _vent valves a's "active" invoking the _operability assurance pro~ram of ~RP 3 *. 9.3. ~GJ-U 1&>05',B The NRC staff has. made site *visits to* several facilities, has t~et with l.icens.e.es 'at Bethesda; Maryland, and has held.telecon conferences with_
~ ~ *
. ~..;
of; OP'P'ICllJi ussions,,. th NRC.stafLha stressed' tha positive ac. i,ons must ~b-e aken as "ti(JteCI"alYtNe" O"""a$"S'O"fe"t1Yift c:*ontaTnmenl'T *te*g*r-rty*wcYuT *b*1nn-aintaine....... ;.......... :..
auRNAMsJ!tn.the... ev..ent.. of. a._..,OBA.. LOCA~--***.................. '............ *.. :....... _,... :******** *:*********,..... :...... _,_... *...... ::.......... :.
. DATB~
- ** : *........ **:** ** : * * '. '" ***. ' ** :<.'........... ':... '.. *..,. '.-::....... '.. ' '...... ':-,. *:.. *.'.. '.,.............. ;_...... .'..... ...... '... *.. ;.... ~..
, me FORM _31s <9.* 76> NROl 02*0
-. 'It u *** ao~.. R.;M.,NT**,.R,NT*NG o.. F.c.., "".... -,. *.
'*-'"' ;:r""*
Mr. D. Louis Peoples As a result of these actions~ we have learned from several licensees that at 1 east three vpl V<;} vendors. have_ reported that their valves may not close against the riscending differential pressure and the resultin~
dynamic: 1 oading of the* design basis LOCfl.*
- l\\l l ic!entifi ed 1 icensees who are affected have proposed to maintain the valves in the closed position or to restrict the angular opening of the valves 1r1henever primary containment integrity-is required until a re-eva"luation*is provided 1;1hich shows satisfactory valve performance under the OB/\\-LOCA condition.
l<ecently, a report und,::r 10 CFR Part 21 was rece.ived by the.NRC from the manufactul'.'er of butterfly valves 1t:hich are installed in the primary cont~inment at the Three Mile lsland Unit 2 Nuclear Station. These butterfly yal ves are usect for pur~Je and exhaust purposes and _ilre _ _requi red '.to operate during accident conditfons.
The report-discusses the use of an unqualified solenoid valve for a safety-related valve function which requires operation.
under accident tonditions.
The solenoid valve i~ used* to pilot control*
the pneumatic valve actuators \\11hich are installed on the containment ventilation butterfly valves at. this facility.
Yo~r re-eva1uation*of valve performance for conditions l1oted in the previous parcgruph must consider the concerns identified in IE Bulletin 79-0H\\.
,L\\s the NRC review progresses, 1 icenser!s whicb might have electrkal override circuitry problems are b.eing advised not to use the override and to take *compensatory interim measures to minimize the prob 1 em.
In 1 ight of the information gained during our n:vic:ws of your submit*~al s dated January 2, July 2, July 5, July 30 and October 4, 1979~ and. the information cited _above, \\*ff: believe an interim commitment from you is required at this time *. This is the cas2, even though you may have proposed
- Technical Spec ific.a.tion changes or other 10119 or short-term measures, which \\*ie are reviewing.
For your use, we have provided as an attachment C!n *interim NRC staff positiono In addition, our r:::cent1y developed 11Guidel ines for Demonstration of Operab il i-ty of Purge and Vent Val ves 11 v1ere pro1f'ided by separate 1 etter to* 1 icens~~es of each opP.rating reactor..
This letter in, no way relaxes any existing licensing reqBirements for your facility o Because of the potent fol adverse effects on the public heal th and safety which could result from the postulated, DBA-LOCA while op~rating with open purge or vent valves, ~*1e believe your prompt* response to,this 1 etter is required.
In accordance \\'Jith 10 cm 50. 54 ( f), you are requr~sted
- .* t t
t I
- t I
OFFIC!l:i'-
.. ;............................... ~-....................... ~.................................................................,:..............................
D~Tll..
- .....,..................,,,...,,.. * '.....,..... *......,,,........,,,.. * **,..,...,..,,......., ~,.....,...I.,.. *.... **.,.. '****'.,*.. * *... ':.... .. *.. *..
- i-ll U.S. GiOV~RNMENT PRINTING Ol"'P"ICEC: 19'10 '"'2Bl5 - 709
,j Mr. O. Louis Peoples
~ 3 -
to. infonn us.in writing.within 4'5 days*'.of receipt-of th'is letter of your commitment to operate in confonnance witti. the.enclosed* interim position and to provide us with' inf9nnatio_n*Y-1'hich demonstrates that you h~ve init'iated the purge and' vent valve operab..ility verificatjon on an expedited basi ~*-
_The fnformation *provided in your response will enable us to detennine.whether or not your license. to operate *Dresden Unit No *. 3 ~and Quad c*ities Units Nos. -1 and 2 'sho_uld be *modified, suspend*~a, :or revoked,.
- )::..
Enc:losure:
Interim Posjtio*n for Containment
. Purge and Vent Valve Operation~
cc: _w/ enc 1 osure See nex~ page Si nc*erel,Y,
- O**i..*;1.:.1 Signe~ bY..
T~ A; lppolit_o Th.omas A. Ippolito,.Chief Oper~ting Reactors Branch. #3 Di.vision of Oper~ting ;Reactors
.. /
/. -.
,/
- ~:~!*~*~;:* **:-&:!"~' : :
.. *~* '."""": :.:....... : "'""""'"";: f "'.......,..............
.. * *: *; *aT * "ii9. ** *........ rol.Ym?:r *
- lo*,.*.. rn~19* * *: * * * * * * * *._. *.:: *.. * *: * * *, * *.. * * * * * * *: *.. * * *... * * * :"*....... '..... *:......... *
- ,DATii........... L~............ _
-.c J.IOml,(' 310 <9-76) ilmoM <me.
\\
I
',.~ * 'dr'u.s. GOVBRNMctftT ~~INTING OP"P'IC~B: 1071........ 710 '
I
_.1
/
Mr. 0. Louis Peoples Conmonwealth Edison_ Company cc:
Mr. John W-. Rowe Isham, Lincoln & Beale Counselors at Law One First National Plaza, 42nd Floor Chicago, Illinois.60603 Mr. B. B. Stephenson Plant Superintendent Dresden Nuclear Power Station Rural.Route #1 Morris, Illinois 60450 Anthony Z. Roi sman -
Natural Resources Defense Council 917 15th Street, N. W.
Washington, D. C.
20005 Morris Public Library 604 Liberty Street Morris, I.llinois 60451 Jimmy L. Barker -
U. S. Nuclear Regulatory Commission P. 0. Box 706 Morris, Illinois 60450 Susan N. Sekuler Assistant Attorney General Environmental Control Division 188 W. Randolph Street Suite 2315 Chicago, Illinois 60601 Mr. D. R. Stichnoth President Iowa~Illinois Gas and Electric Company 206 East Second Avenue Davenport, Iowa 52801 Mr. Nick Kalivianakas Plant Superintendent Quad Cities Nuclear Power Statopn 22710 - 206th Avenue - North Cardova, Illinois 61242 Moline Public Library 504 - 17th Street Moline, Illinois 61265 Mr. N. Chrissotimos, ]nspector US Nuclear Re.gul atory Commission Box 756 Bettendorf, Iowa 52722
1...
- ~
INTERIM POSITION FOR CONTAINMENT PURGE AND VENT VALVE OPERATION PENDING RESOLUTION OF ISOLATION VALVE OPERABILITY Once the conditions listed below are met, restrictions on use of the containment purge and vent system isolation valves will be revised based on our review of your responses to the November 1978 letter justifying your proposed operational mode. *The revised restrictions can be established separately for each systeni.
- 1. Whenever the containment integrity is required, emphasis should be placed on operating the containment in a passive mode as much* as possible and on limiting all purging and venting times to as low as achievable.
To justify venting or purging, there must be an established need to improve working conditions to perform a safety related surveillance or safety related maintenance procedure.
(Examples of improved working conditions would include deinerting, reducing temperature*, humidity*,
- and airborne activity sufficiently to permit efficient performance
.or to significantly reduce occupational radiation exposures), and
- 2. Maintain the containment purge and vent isolation valves closed whenever the reactor is not in the cold shutdown or refueling mode until such time as you can show that:
- a.
Al 1 isolation valves greater than 3 11 nominal diameter used for containment purge and venting operations are operable under the most severe design basis accident flow condition loading and can close within the time limit stated in your Technical Specifications, design criteria or operating procedures. The operability of butter-fly valves may, on an interim basis, be demonstrated by limiting the valve to be no more than 30° to 50° open (90° being full open).
The maximum opening shall be determined in consultation with the valve supplier. The valve opening must be such that the critical valve parts wi 11 not be damaged by DBA-LOCA 1 oads and that the valve will tend to close when the fluid dynamic forces are introduced, and
- b. Modifications, as necessary, have been made to segregate the containment ventilation isolation signals to ensure that, as a minimum, at least one of the automatic safety injection actuation signals ts uninhibited and operable to initiate valve closure when any other isolation signal may be blocked, reset, or overridden.
- Only where temperature and humidity controls are not in the present design.