ML20197D340
| ML20197D340 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 05/07/1986 |
| From: | Long W Office of Nuclear Reactor Regulation |
| To: | Pilant J NEBRASKA PUBLIC POWER DISTRICT |
| References | |
| NUDOCS 8605140237 | |
| Download: ML20197D340 (10) | |
Text
,
May 7, 1986 4
a Docket No. 50-298 DISTRIBUTION Docket File EJordan NRC PDR BGrimes Local PDR JPartlow J
Mr. J. M. Pilant, Technical Gray File ACRS(10)
Staff Manager RBernero OELD Nuclear Power Group SNorris WLong Nebraska Public Power District Post Office Box 499 Columbus, Nebraska 68601
Dear Mr. Pilant:
SUBJECT:
CONTAINMENT VENT AND PURGE ISSUES Re:
Cooper Nuclear Station i
Your letter dated March 3,1986 discussed several issues that remain open regarding containment vent and purge.
Following are the staff's comments on
]
those issues.
1.
Debris Screens In accordance with your commitments of July 19, 1984 and March 3,198G you should proceed with plans to install Category I debris strainers during the forthcoming outage.
2.
Modification of Purge Valve Operators Valve modifications described,in your December 15, 1983 letter (valve reorientations, valve blocks and torque switch readjustments) are acceptable. Modifications not yet performed should be performed during the forthcoming outage.
5 3.
Leak Rate Testing The information provided in your September 3,1985 does not justify an exception to the staff position on quarterly leak rate testing of isolation valves. Your October 8,1985 telecopy (copy enclosed) proposed alternative Technical Specifications. We have attached for your consideration, an enclosure suggesting further changes.
In addition to the issues discussed in your March 3,1986 letter, certain Technical Specifications issues remain to be resolved.
Following the test proposed in your September 3, 1985 letter, you should submit a Technical Specifications (TS) amendment request for the following items.
1.
To implement TS (pages 166, 167, 165a, and 183) as proposed in your July 19, 1984 letter, or as proposed in your October 8,1985 telecopy, depending on results of testing of the capability to purge via ti.e 2-inch alternate flow path.
B605140237 860507 PDR ADOCK 05000298 P
. 2.
To require surveillance of the 60-degree valve blocks once per cycle if the blocks are of a design which would permit drift or detachment.
3.
In addition to the above we also recomrend that TS 3.7.D.2 be changed to specify that wren a single isolation valve is used for an extended period of time to provide containment integrity, the valve must be deactivated in the closed position.
Sincerely, William 0. Long, Project Manager BWR Project Directorate #2 Division of BWR Licensing
Enclosure:
As stated cc w/ enclosure:
See next page L
DBp:PD#2 DBL:PD#b DBL:PD#2 SNaiVTs:rs WLong D
4/2ff/86 4/gg/86 4
6
Mr. J. M. Pilant Nebraska Pt.blic Power District Cooper Nuclear Station ec:
Mr. G. D. Watson,. General Counsel Nebraska Public Power District P. O. Box 4999 Columbus, Nebraska 68601
!!r. Arthur C. Gehr, Attorney Snell & Wilmer 3100 Valley Center Phoenix, Arizona 85073 Cooper Nuclear Station ATTN: Mr. Paul Thomason, Division Manager of Nuclear Operations P. O. Box 98 Brownville, Nebraska 68321
~
Director f;etraska Department of Environmental Control P. O. Box 94877 State House Station Lincoln, Nebraska 68509 P.r. William Siebert, Comissioner Netaha County Board of Comissioners Necaha County Courthouse Auburn, Nebraska 68305 Resident Inspector U.S. Nuclear Regulatory Comission P. O. Box 218 Brownville, Nebraska 68321 Pegional Administrator, Region IV U.S. Nuclear Regulatory Comission E
611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76011 H. Ellis Simons, Director
~
Division of Padiological Health Department of Health 301 Centennial Mall, South P. O. Box 95007 i
Lincoln, Nebraska 68509
!f g
'a
/6l0$
(
N,6 t: W Nebrooks Public I%wer Ihatrict
==
=
~
FACSIMILE INFORMATION TICKET f
[fff
/qh Phbes General OfEce 9 7J2f b a #_
7 m
rrm i
MRC - yh -h WB8
!b;
.+ n gr re. L Imier L
Se L da 4 Afaea lud i
~
a... a.e l'
(~
W Total Minnbar erPingas 5%4=siing this leJ z== ham 11rast n%
i werow--%c<* ooo 171 + V ! o li t=
e5
- 8 TRAN!MfrTED FRON:
(
NEBRASKA PUBtJC POWER DISTRICT 1414 Itish Straus rhbum, Nebranka 0n01 Nam 2 A t-91# (Andr==hr)-(400 SSl2fi61 (Anda===he Speed %&rei-)
~
?$
348 E0BB(A=h-stic)-(4mg 563486 m
a.
Operates at 6 h-a )
g-r PsJoarTY BANDMNG a
I s
$ =h-e
, id
%M
.[
v h,
LIMIT 2NC CONDITIONS FOR__OptRATIOR SMVIILLANCE REQUIRDENTS r
3.7.A (Cont'd) 4.7.A.1.f (cont'd) 1
- 4. Main steam line and feedveter line expansion bellows as specified in Table 5.7.3 shall be tested by pressurising between the laminatione of the bellows at a pressues of 5 pets.
This is an exemption to Appendia J of 10Craso.
- 5. the personnel airlock shall ne tested at 58 pois at intervale no lenger than sia months. This testing may be essended to the nest refueling outage (not to exceed to months) provided that there have been no airlock openings since the last successful test at 55 pois.
In the event the personnel airlook is set opened between refueling outages it shall be leak checked at 3 peig at tatervels no longer than six sonths.
Within three days of opening (or every three days during periods of frequent opening) when sentainment integrity is required, test the personnel airlock at 3 peig.
This is an euesprion to Appendis J of 10CTR50.
3 Additional teakene Tests Additional testing shall be performed to detect exeessive leakage due to wear of the purge and vent isolation valve resilient seats. The valves will be tested by paire (PC-131MY and PC-246AV, PC-230MT and PC-245AT, PC-132HV and PC-138AV, FC-135t? and FC-237&V) in accordance with the following schedulet 1)
Every pair once overy 3 months until 30 successive teste have passed, then
- 11) Beery pair once every 8 aanths until to additional sueesseive teste hava passed, then there-atter iii) in assordance with Speettisa-tien 4.7.A.2.F.1.
j (g
1
-162a-10N/35 i
f Fm 7m *m RRNLJ-Lala-catt 82:60 58/80/0I
, 8p ee m se:23 NePD COLUMBUS GO N0 001 883 0
2.IMITING COND2T20N8 FOR OPERATION
_ SURVIILLAllC5 RE@IRDGWT5
{
3.7.A (Cent'd) 4.7.A.2.f (cont'd) 3 Additional teskame Teete (cont'd) l A test is considered a failure only if the leakage from the two valves exceeds 200 esf/hr and has been determined to be caused solely hy the failura of the resilient seate due to wear and not due to sons other cause such as valve operator malfunction, etc.
h.
Drywell Surfasse The interior surfaces of the drywell and torus shall be visually inopseted each operating eyele for evidence of torus corresten or leakage.
(W G
s l
O
-162b-10/7/85
i
.22<2E/95 88:23 M PD COLUMBUS GO NO.901 ges LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIRDENTS r
3.7.5 (cont'd) 4.7.3 (cont'd)
Q4 If these conditions cannot be met.
4.s. At least once per operating eye 1e procedures shall be initiated automatie initiation of each branch of imediately to establish resetor the standby gas treatment system shall conditions for which the standby be demonstrated.
gas treatment system is not required.
b.
At least once per operating cycle Danual operability Of the bypass 5.
Use of the standby Oss Treatment valve for filter cooling shall System for purging / venting the be demonstrated.
primary containment with both the inboard and outboard exhaust isola-c.
When one circuit of the standby gas tion volves open in series fror, the treatment systes becoses inoperable dryve11 (231MV and 246AV) and/or the other circuit shall be demon-the Torus (230MV and 245AV) is strated to be operable imediately limited to 120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br /> per calendar and daily thsreafter.
year when coolant temperature is greater than 200*F.
C.
Seeendary Containment 1.
Secondary centeinsent integrity shal l 1.
Es eendary containment surveillance be maintained during all modes of shall be performed as indicated plant operation except when all of belows the following condittene are met.
f l
1 i
e 4
-165a-10/7/ss m
9
.T**
"f 'd*h"'
E !?*
f?'?"'" L.
~ J
I
~y 88:22 P PD COLUMBUE GO No.Bei 805 l
..V 3.7.A & 4.7.A M (eent'd)
I check of the temperatura and volume is adequate to aneurs that adequate heat reseval espability is present.
i h The intent of Specification 4.7.A.2 3 to to test for grose leakage of the resilient j
eeats in purge and vent isolation valves due to wear. These teste dre in addition to 10CFR50. Appendix J requiremente and can exceed the leakage criteria of Appendix J.
The NRC has determined that based upon CNS historical seat failure data. 200 sef/hr is an acceptable criteria to sake a determination of grose i
leakage. Additionally, causes of leakage, other than wear of the resilient osats, can be determined and corrected with the test being performed esain without being l
toccidered a failure.
If a pair of valves fails the gross leakage test and it is known that one of the valves has not been operated since the last successful test, then edequate containment isolation exists because that valve had passed the previous test and had not subsequently been operated, subjecting its seat to wear. If a pair of valves fails the gross leakage test and both the valves had been operated einse their last successful test, then no assurance exists that the failure was due to only one valve. The seats will have to be ineyscued and replaced as needed.
The interiors of the drywell and suppreeston chamber are painted to prevent rusting. The inspection of the peint during each major refueling outage.
apptcxinately once per year, soeures the paint is intact. fxperience with this type of paint at fossil fueled generating statione indicates that the inspection interval is adequate.
4 j
3.7.A.3 & 4 and 4.7 A.3 & 4 VACUUM 5ttAKERS The purpose of the vacuum relief valves to to aquelise the preneurs between the dryve11 and suppreseien chamber and resetor butiding so that the structural integrity of the containment le maintained. The vacuus relief system from the pressure suppression ehember to resetor buildtog eensists of two 1005 voeuum l
relief breakers (2 parallel sets of 2 valves in maries). Operation of either system will maintain a pressure differential of less than 2 poi, the enternal design pressure. One valve may be out of service for repairs for a period of 7 days.
If repaire cannot be cetpleted within 7 days the reactor coolant syntes is brought to a condition where vacuum relief is no longer required.
The capacity of the 12 drywell vacuum relief valves are eised to limit the pressure i
differential between the suppressien chaa.ber and drywell during post-steident dry-I' well cesling operations to well under the design limit of 2 pai. They are eised on the beefs of the Bodese Bay pressure suppressica system tests. The AgME Boiler and Pressure Vessel Ceda, section III, Subsection B, for this vessel allows a 2 ysi differentials therefore, with three voeuut relief valves soeured in the closed positten and 9 operable valves, containment integrity is not tapaired.
3.7.A.5 and 4.7.A.5 OKYGEN CONCENTRATION gefety Cuide 7 soeuaptions for Metal-Water reaction result in hydrogen consentration in excess of the Safety Outde 7 flammability limit.
By keeping the owygen eencen-tration less than 45 by voluso the requiremente of Esfety cuide 7 are satisfied.
l The occurrence of primary system leakage following a major refueling i(&
outage or other scheduled shutdown is much more probable than the i
-179-to/7/ss w
muav aswam m.mvar
j- ;
19e28/95 88a25 ffPD COLUMBUS GO NQ. 991 806 3.7.A & 4.7.A M (cont'd) i occurrence of the loss-of-coolant accident upon which the specified oxygen concentration limit is based. Permitting access to the drywell for leak inspections during a startup is judged prudent in terms of the added plant safety offered without significantly reducing the margin of safety. Thus, to preclude the pessibility of starting the reactor and operating for extended I
period of time with significant leaka in the primary syntes, leak inspections j
are scheduled during periods when the primary system is at or near rated operating temperature and pressura. The 24-hour period to provide inerting is judged to be sufficient to perform the Igek inspection and establish the required oxygen concentration.
The primary centainment is normally slightly pressurised during periode of reestor operation. Nitrogen used for inerting could leak out of the containment but air could not leak in to increase oxygen concentratten. Once the containment is filled with nitrogen to the required concentration, no monitoring of oxygen concentration is necessary. Bovaver, at least twice a week the osygen concentration will be determined as added assurance.
no 500 ge11on conservative limit os the nitrcgen storage tank assures that adeguate time is available to get the tank refilled assuming normal plant operation. The estimated maximum r.akeup rate is 1500 ScrD which would require about 160 gallone for j
s 10 day makeup requirement. The normal leak rate should be about 200 gCFD.
)
3.7.5 & 3.7.C STANDBY CAS TIUtATMENT SYSTDI AFD SECOND(W CONTAINMENT The secondary containmant is designed to zinimise any ground level release of radio-active materials which might result from a serious accident. The reactor building provides secondary containment during reacter operation when the drywall is sealed and in service. The reactor building prevides primary containnaet when the reactor is shut down and the drywell is open, as during refueling. Because the secondary centainment is an integral part of the cceplete containment system, secondary con-tainment is required at all times that primary containment is required as well as during refueling. Secondary containsient may be broken for short periods of time to allow access to the reactor building roof to perform necessary inspections and maintenassa.
The standby gas treatment system is designed to filter and exhaust the reactor 1
butiding assespheve e. eha etask durins sesondary v.ontalumeut ieuleLiwu uvud1619ue.
Both standby gas treatment system fans are designed to automatically start upon containment isolation and to' maintain the reactor building pressure to the design negative pressure so that an leakese eheuld be in-leakage. Should one system fail to start, the redundant system is designed to start automatically. Each of the two fans has 100 percent espacity.
The intent of specification 3.7.3.5 is to minimise the tima the SBOT system is on line while coolant temperature is 3 eater then 200*F and both inboard and outboard enhaust isoistion valves from the d:ywell and/or torus are open in series. The concern is to decrease the probability of damage to the BBCT filters that would occur from excessive differential pressure seused by a LOCA with the main isolation ewheust valves open in series. Thin specification does allow purge / venting with the bypass around the inboard exhaunt valve and the eusboard exhaust valve both open in series and the time does not sount assinet the yearly limit. The NRC has
(
determined that due to the sea 11 sine of the bypass valve, there is no chance of desage to the filters if a 1.0ei oscure.hite,urgin.fv.ntin, th. sentainn.nz through the bypses with the SSCT system on line.
-180-10/7/85 dW*
M
SUGGESTED TECH SPEC 4.7.A.2.g - ADDITIONAL LEAKAGE TESTS 1
Additional testing shall be performed to detect excessive leakage due to wear of the purge and vent isolation valve 4
resilient seats. The valves will be tested by pairs (PC-231MV and PC-246AV, PC-230-MV amd PC-245AV, PC-232MV and PC-238AV, PC-232MV and PC-237AV) in accordance with the following schedule.
1)
Every pair once every 3 months until 50 successise valve pair te:t: have pa::cd, then 11)
Every pair once every 6 months until 20 additional successive valve pair tests have passed, then iii)
In accordance with Specification 4.7.A.2.F.1.
iv)
If at any point in the testing scheoule a valve j
pair test is not passed, the testing schedule will resume at 1).
l 2
1
!