ML20077J177
| ML20077J177 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 07/25/1983 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20077J176 | List: |
| References | |
| TAC-51838, NUDOCS 8308150486 | |
| Download: ML20077J177 (5) | |
Text
.
}-
SAFETY EVALUATION AftENDriEHT NO. 20 TO NPF-10 SAN OM0FRE HUCLEAR GENERATING STATION, UNIT 3 DOCKET NO. 50-361 Introduction By letter dated January 6,1983, the Southern California Edison Company (SCE or the licensee) requested an amendoent to change the San Onofre Nuclear Generating Station, Unit 2, Technical Specifications to grant temporary exceptions to Technical Specifications 3.4.1.2, 3.4.1.3, and 3.7.1.3 to pemit natural circulation tests to be conducted as part of the startup testing program. These exceptions'will be granted by modifying Technical Specification 7.0, Special Test Program, to specifically pemit the exceptions during natural circulation testing only.
i Sumary In its submittals of April 15, 1982 and January 6,1983 the licensee described 4
the natural circulation tests which will be conducted by turning off all 4
four eactor coolant pumps. This is not nomally pemitted by the facility Technical Specifications, but is necessary for the conduct of these tests.
In their submittals the licensee evaluated the tests to investigate the-l probability and consequences of the accidents described in Section 15 of-the FSAP., as well as the possibility of accidents of a new or different kind, and also evaluated the safety cargins during the tests.
In some instances, specific operator actions are necessary, during the conduct of the tests, to keep the potential accident probability or consequences or safety nargins within the limits previously evaluated in Section 15 of the FSAR and approved in the staff's Safety Evaluation Report and its supplements (NUREG-0712).
The licensee has included all such actions in the detailed test procedures that the plant' operators will be required to follow during the tests. These operator actions are described in Section 3.0, Operational and Test Temination Criteria, of CEH-201 (3), "flatural Circulation Test Program," Supplement-Ho.1, submitted by the licensee on January 6,1983.
~
The staff has concluded that relaxation of the requirements of Technical Specifications '3.4.1.2, 3.4.1.3. and 3.7.1.3 is acceptable because it will be accompanied by compensatory actions that caintain a commensurate level of safety to that provided by the Technical Specifications.
Such compensatory.
neasures include temination of the test and restoration of at least one reactor coolant loop to operation in the event of. abnomal systen parameters.
The details of the staff evaluation of each of the proposed changes is given below.
8308150486 830725 DR ADOCK 05000361 p
PDR omcn >
suams >
omy OFFICIAL R ECOR D COP _Y
. usam m-mm nncfonu m oo-soq uacu om
. Evaluation (1) Technical Specification 3.4.1.2 - Reactor Coolant Systen: llot Standby This Technical Specification covers the reactor coolant loops and coolant circulation in hot standby and requires that at least one reactor coolant loop and its associated steaa ger,erator with at least one associated reactor coolant pump be in operation. The operation of one reactor coolant punp provides adequate flow to ensure quick mixing of added boron, prevent possible tenperature stratification, prevent possible boron stratification, and produce gradual reactivity changes during boron concentration reductions in the reactor coolant system. Consequently; with no reactor coolant loops in operation while in hot standby, all activities involving a reduction in boron concentration are required by this Technical Specification to be suspended and imediate corrective action is required to return the required loop to operation.
!!owever, during the perfonaance of the "B" series of natural circulation tests, operation of both reactor coolant loops will be interrupted by utentionally renoving power to all four reactor coolant pumps.
In Test 81 and B2 the plant will be naintained in hot standby with offsite AC power removed, and in Test 83 the plant will be taken fron hot standby to temperatures and pressures that pennit the initiation of the shutdown cooling systen under conditions that sinulate a loss of offsite power.
In both tests, however, no operations will be pemitted that could cause a dilution in the reactor coolant systcn boron concentration and an acequate loop subcooled margin will be naintained at all tines. Also, as a compensatory neasure, the tests will be teminated if any of the critical paraceters identified in the test procedure (i.e., hot and cold leg temperature, reactor coolant systen subcooled margin, reactor coolant systen pressure, and stean generator level) is exceeded.
Cased on the above, the staff concludes that the groposed exception to Technical Specification 3.4.1.2 pernitting the "B series natural circulation tests to be conducted is acceptable.
(2) Technical Specification 3.4.1.3 - Reactor Coolant Systen: 110t Shutdown This Technical Specification covers the reactor coolant loops and coolant circulation in bot shutdown and requires that at least one reactor coolant loop and its associated stean generator with at least one associated reactor coolant pump or shutdown cooling Train A or shutdown cooling Train B be in operation. The operation of at least one of the above systems provides adequate flow to ensure quick mixing of added boron, prevent pcssible tenperature stratification, prevent possible boron stratification, and produce gradual reactivity changes during boron concentration reductions in the reactor coolant systen. Consequently, with no reactor coolant loop or shutdown cooling train in operation while in hot shutdown, this Technical Specification requires that all activities involving a reduction in boron concentration be suspended and 1 mediate corrective acticn y tonn
+n ro +,,v n +be enc,. ira innn nr +rmin in amentfan OFFICE )
SURNAME) c:.sa y nnc ronu sia tio-ao> uncu oao OFFICIAL RECORD COPY usoeo: mi-m..e.
- However, during Natural Circulation Test B3, the plant will be taken from hot standby to temperatures and pressures that permit the initiation of the shutdown cooling system under conditions that simulate a loss of offsite power, i.e., with all four reactor coolant pumps secured. The shutdown cooling systen will not be placed in operation.
In this test, however, no operation will be pernitted that could cause a dilution in the reactor coolant systen boron concentration and an adequate loop subcooled cargin will be naintained at all times. Also, as a compensatory measure, the tests will be terminated if any of the critical parameters identified in the test procedure (i.e., hot and cold leg temperature, reactor coolant system subcooled margin, reactor coolant systen pressure, and steam generator level) is exceeded.
Based on the above, the staff concludes that the proposed exception to Technical Specification 3.4.1.3 pernitting natural circulation test B3 to be conducted is acceptable.
(3) Technical Specification 3.7.1.3 - Plant Systens: Condensate Storage Tank This Technical Specification covers the condensate storage tanks and requires that both tanks be operable, with a contained water volume of at least 123,000 gallons in T-121 and 280,000 gallons in T-120.
(Note that 123,000 gallons is the required volune for tank T-121 corresponding to a naximun achieved power of 80%.) Operability is demonstrated by verifying that the contained water volume is within this limit once every twelve-hour period.
The operability of the condensate storage tanks with the minimua water volume ensures that sufficient water is available to maintain the reactor coolant systen at hot standby conditions for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with stcan discharge to atmosphere concurrent with a total loss of offsite power.
During the performance of the "B" series of natural circulation tests, the auxiliary feedwater system will be used to feed both stean generators.
As a result, the contained water volume in tank T-121 nay fall below the required 123,000 gallon ninimum. However, the decay heat level that was assumed when calculating this nimimum volume is based upon a reactor trip following approximately two years of sustained power operation at 80% of rated thermal power. The actual decay heat level that will exist when Tests B1, B2 and 83 are performed will be considerably less than this assumed value. Therefore, operation with tank T-121 value; below 123,000 gallons for sh. ort periods of time during the "B" series of natural circulation tests will not impact plant performance since the margin of safety as defined in the basis for the condensate storage tank technical specification will not be reduced.
Based on the above, the staff concludes that the groposed exception to Technical Specification 3.7.1.3 permitting the "B series natural circulation tests to be conducted is acceptable.
omcr >
suRnus) omy NRC FORM 318 (10-80) NRCM ONO OFFiClAL RECORD COPY usoeo a i-m ma
r w
. Contact With State Official 3y copy of a letter dated June 10, 1983 to the licensee, the NRC staff advised the Chief of the Radiological Health Branch, State Ocpartnent of Health Services, State of California, of its proposed determination of no significant hazards consideration.
Also included in the transmittal package were the licensee's application for the anendment and the supporing documents. No comments were received.
Environnental Consideration We have determined that this amendnent does not authorize a change in effluent types or total amount nor an increase in power level and will not result in any significant environmental impact. Having nade this determination, we have further concluded that this anendment involves action which is insignificant from the standpoint of environmentaT impact and pursuant 10 CFR Section 51.5(d)(4), that an environnental impact statenent or negative declaration and environnental inpact appraisal need not be prepared in connection with the issuance of this amendment.
Conclusion Based upon our evaluation of the proposed changes to the San Onofre, Unit 2 Technical Specifications, we have concluded that:
there is reasonable' assurance that the health and safety of the public will not be endangered by operation in the proposed nanner, and such activities will be con-ducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public. We, therefore, conclude that the proposed changes are acceptable.
Dated:
JUL 2 51983 l
4
- See )'evious concurrence.
DL:LB#3 DL:LB#3 OELD "
C FFICs) suaune >
......k.. /83......
.... 7../....../. 8. 3......
7../
7
/83
,m>
- Nac ronu s a co q uacu om OFFICIAL RECORD COPY usc n -mm
-4 Contact With State Official By copy a letter dated June 10, 1983 to the licensee, use NRC staff advised th Chief of the Radiological Health Branch, State Department of Health Servi s, State of California, of its proposed determination of no significant azards consideration.
Also included in (e transnittal package were the licensee's application for the anendment and the supporing documents. No comments were receiv Environnental Conside tion We have determined that s anendeent does not authorize a ange in effluent types or total amount nor an increase in power 1 el and will not result in any significant en'y ronmental impact. Havin.
ade this deternination, we have furthe oncluded that this a ndment involves action which is insignificant een the standpoint environnental impact and pursuant 10 CFR Section 51.S{ (4), that an nvironmental impact statement or negative declaration d enviro ntal impact appraisal need not be prepared in connection with he iss hce of this amendment.
Conclusion S anges to the San Onofre, Unit 2 h
Based upon our evaluation of the oposed Technical Specifications, we have concluded (that:
(b vecause tnis amenumm.
involve a sisu;fic:n+'4acs:sase ia t presitity er renteg::::; -
,y c =
not vi a % uen o previvuso u;.. dew, he a ^ t,~ : : t; 1 6 vess4414+y ef n eacc1 dent of a type differd;t
ay av21"2+= Anesvhly_ M%s= net" f r
4 vcive a tigr**ic:nt p frc::e i-2 safety margi M P : -Wat de=s not
-46,vi ve a signi ricasif soi c 67 isto, de cc65idcrati:9-there is reasonable c
assurance that thejrealth and safety of the public not be endangered by operation in t)e proposed canner, andpsuch ac vities will be con-ducted in compl)6nce with the Conmission s regulations nd the issuance of this amen
.nt will not be inimical to the connon de nse and security or to the h lth and safety of the public. We, therefore conclude that the proposed anges are acceptable.
Dated:
/
h' d
6 s
@ }y$
%fd j h Pd#<-Q.
t ca yNh e/Ek!
g <w/ '
- T) N l
v c mc.>..DL:IS6...........Ei.M...k I
i
.u _.>..m.9.ca...... mm.93..........'.b.
..7L2219%.......... 7L.191.........LL91.....
=m>
' unc ronu ais tto-so3 Nacu o24o OFFICIAL RECORD COPY uscro:im-== -
t 1
JUL 2 51983 DISTRIBUTION i
l-N 7CniW 6 E (504361) F NRC PDR L PDR
(
NSIC l
PRC System LB#3 Reading HRood JLee (12)
GWKnighton J
LChandler DEisenhut/RPurple HRDenton TMNovak JRutberg, OELD AToalston, AIG ELJordan, IE JMTaylor,.IE LJHarmon, IE (2) 1 JSauder WMiller IDInitz WJones, 0A TBarnhart(4)
BPCotter, ASLBP I.
ARosenthal, ASLAP
{
ACRS (16)
FPagano, IE i
i i
1 r
l f
I-1 l
. _,