ML19339A771
| ML19339A771 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 06/20/1961 |
| From: | Jensch S US ATOMIC ENERGY COMMISSION (AEC) |
| To: | |
| Shared Package | |
| ML19339A769 | List: |
| References | |
| NUDOCS 8011040758 | |
| Download: ML19339A771 (16) | |
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UNITED STATES OF AMERICA ll'l ATOMIC ENERGY COMMISSION IN THE MATTER OF
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DOCKET No. 50-29 YANKEE ATOMIC ELECTRIC CC)MPAhl
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Appearances I.
Donald G. Allen, Esq., and Allen O. Eaton, Esq.
For Yankee Atomic Electric Company Troy B. Conner, Jr. Esq., and William R. Stewart, Esq.
For the Staff'of the Atodic' Energy Cocmission FUTH INTERMEDIATE DECISION AND AUTHORIZING POWER OPERATIONS TO 485 MEGAWATTS THERMAL Yankee Atomic Electric Ccepany of Boston, Massachusetts, (Yankee) on February 13, 1961, filed with the Atomic Energy Commission a report covering the operation, under previously issued Commission License No. DPR-3, of f
its nuclear power utilization facility, located in Rowe, Massachusetts, during a six month's period ending January 29, 1961, as well as results of a 500-hour test run at 392 cegawatts thereal (MUT) which was ccepleted on February ?,1961. This report of these operations was required of II Yankee by virtue of the terms of the operating license issued in I/ The,p_crtinent provision of tbc license _is as follows:
- This license is effective as of the date of issuance and shall ex-pire upon the effective date of a final decision by the Commission folicwing a public hearing to be held respecting operations of the facility at the 392 MW (thereal) steady state power level af ter the filing by Yankee with the Secretary of the Commission of the report required under paragraph 3.C.(2) of this license. Such hearing will be held upon 15 days notice to the public and no later than 90 days following the filing of the aforesaid report."
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accordance with 'the Third Intermediate Decision cade effective by the Cc= mission on July 19, 1960, and is needed as a basis for consideration of any request for authority to operate the nuclear reactor at any in-creased power level.
On March 31, 1961, Yankee filed Amendment No. 25 to its original application for an operating license and thereby requested that License No. DPR-3 be further amended so as to authorite operation h
of its nuclear power utilization facility at steady state power levels L
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not in excess of 485 MRI and to extend the expiration date of the license to a date forty years after the date of Construction Permit No. CPPR-5, b
issued on November 4, 1957.
On April 25, 1961, the Cemmission issued a Notice of Hearing pro-
"5 viding for a public hearing to be held on May 12, 1961 as conte = plated by
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the terms of the license issued to Yankee, with the issues specified as follows:
(1) Whether on the basis of the report dated February 13, 1961, filed by Yankee, the processes to be perforced, the operating procedures, the facility and equipment, the use of the facility and the technical specifications, collectively, provide reason-able assurance that the alth and safety of the public will not be endangered by operation of the facility at power levels up to 392 cegawatts thermal steady state.
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(2) Whether or not an operating license should be issued to the Yankee Atemic Electric Company pursuar
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the Commission's regulations (10CFR Part 50), such license to expire on a date 40 years af ter the date of the Construc-k.i E
tion Permit CPPR-5, which was issued on November 4, 1957, and g
I whether the license proposed to be issued for a period of 40 g==:
il years would then expire on Novecher 4,1997.
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On April 25, 1961 the Staff filed a cotion to postpone the date of g =g hearing until June 1, 1961, or a later date, and to enlarge the issues
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in the proceeding to include:
Whether, Facility License No. DPR-3, as amended, should be further amended to increase the maximum authorized power level E.cm 392 cegawatts (ther=al) to 485 megawatts (thereal).
This cotion was based upon the ground that by a postpone =ent, the Advisory Ccemittee on Reactor Safeguards cay have an opportunity to consider Yankee's Amendment No. 25 r, questing authority for a pcwcr level of 485 ERT. Yankee concurred in th1 cotion, which was granted, the issues to be considered were enlarged and postponement was cade on May 12, 1961 to June 8,1961, when the case convened.
No persons sought permission to ee intervene in the proceeding nor to otherwise participate in the pro-ceeding in accordance with the Rules of Practice of the Ccemission.
- q The case ras concluded on June 8,1961, after which the participants submitted proposed findings and conclusions and cce=ents, the last on June 12, 1961.
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4 Yankee's report of operations at 392 MUT and the data submitted in support of its request for an increase of pcwer to 485 MUT were reviewed by the Advisory Cecmittee on Reactor Safeguards on May 18, 1961.
The Committee's report dated May 22, 1961 was included in the public record in this proceeding and in part is as follows:
9 "In previous letters dated February 1, 1960, May 9, 1960, and June 27, 1960, the Committee dealt with safety matters including those covered in the Final Hazards Sucmary Report, Technical 23.
The Specifications, and all pertinent amendments through No.
one major point which was unresolved related to testing the reac-tor for effects of plutonium build-up at about 2000-hour intervals.
In letters dated October 21, 1958, February 1,1960, and May 9, U===e-1960, the Committee indicated that such testing could be done in the reactor without undue hazard, but that the program and its results should be reviewed by the Committee. The program and its results to date have been reported by the applicant. The t
Ceccittee finds the procedures to be acceptable and notes that
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there have been no detectable effects of plutonium build-up during the first 2000-hour period. The Co=mittee believes that continued use of in-core monitoring of at least the first core is essential The to an understcuding of how the core is changing with time.
Ccemittee wishes to be kept informed of any significant data that may be developed in this program.
" Amendments 24, 26, 27 and 28, and Proposed Changes 1-8 deal with cinor modifications to the plant and chaages in the Technical Specifications. These snould be worked cut by Yankee Atomic Electric Comp ny and the AEC staff. A=endment 25 is a request to amend License No. DPR-3 so as to authorize operation of tne reactor at steady state power levels to 465 MU(t) and to extend the expiration date of the license to a date forty years after the expiration date of the construction permit.
'7 tis the opinion of the ACRS that with continued surveillance of the plant by the applicant, as proposed, the plant can be operated at steady' state pcwer levels of approximately 485 MW't), with the changes requested, without undue ha=srd to the healti, and safety of the public."
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- 7 The foregoing designated third intermediate decision provided for
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a substantial period of test cperation prior to the issuance of a permanent operating license, in order to confirm the design character-istics of the reactor by actual experimental data. The maximum authorized power level of the reactor during this period was limited to 392MkiTtocorrespondvjththedesigncriteriaestablishedfortheinitial Yankee had presented evidence that the initial' core had'been b
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deliberatelyunderdesigned in the expectation that actual performance
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would exceed design specifications, and might.well prove adequate for
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h operation at the full nominal rating of the plant of 485 !sT (estimated p
to correspond to 145 WE, or 136 MWE af ter deducting station use).
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I was concluded, however, that the final increase of power to 485 MWT n
could better be evaluated after the results of operation at 392 MWT had been established.
In the technical specifications, which are a part of the Yankee License No. DPR-3, provision was made for the procedure to be folicwed during the initial start-up of the Yankee reactor, including the tests to be performed prior to core loading, the prccedures to govern initial
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core loading and the approach to initial criticality, and the tests to be performed at icw pcwer and during initial power operations as step-wise increases were made to the caximum power level of 392 INT authorized by the, license which was provisional in this respect.
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6a Prior to the issua'nce to Yankee of the operating license on July 9 1960, construction of the reactor and all associated systems had been completed so far as possibic prior to the introduction of the initial fuel material, and all necessary preoperational testing had been satis-factorily accocplished.
Af ter issuance of the operating license, the reactor vessel head was removed and the reactor vessel was filled with borated water to the core loading icvel.. Core loading commenced on July 15 with the installation of the first neutron source. Af ter calibration and adjustment of the temporary neutron detectors, core loading proceeded with the installation g
of the shim rods and-thereafter with individual loading of control rods and fuel elements. JCore loading was carried out in accordance with b
cperating restrictions in the technical specifications which required boron concentrations to be maintained at a level sufficient to render the fully loaded core at least 10% subcritical, and permitted core load-ing to be continued only if a projection of inverse source cultiplication ecunt rates itsicated that the core would remain suberitical with double the number of fuel assenblies then in place. Core leading was completed on July 26. HNorect-plant source range instrumentation was then rested and more sensitive source range -detectors were installed when it was found that the detectors originally installed vould not give satisfactory 2/
readings from the neutron sources through heavily borated water. The con-trol rod drive shafts and the in-core nucicar instrumentctica verc then installed. Final closure of the reactor vessel was delcyed while the ports.y in the vessel head were enlarged to accccmodate the in-core instrumentation.
2/ Yankee replaced the initially installed source range detectors with more rensitive detectors.
3/ The evidence frc= Yankee was that a major delay was occasioned by a mistake Tn design which resulted in a misfit between the in-core instrumentation Icad columns and the ports in the ressel head through which they pass.
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Electrical leads from the in-core f.nstrumentation and the control 4/
I" rod drive meenanisms were 'then connected and tested, and cold drop tests were performed to verify functioning of the concrol rods.
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On August 19 the initial approach to criticality was cocmenced by
- v the partial withdrawal of 'the outer group of control rods.
The remaining groups of cor rods were withdrawn in small increments, and initial j-criticality was achieved with all control rods slightly more than one-third withdrawn.
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The period from August 19 to November 10, 1960 was devoted to 1cw-g power testing in accordance with a schedule previously described in the Eg license application and incorporated in the technical specifications.
An expanded test program on control rod drives and rod drop times was f::
carried out at operating temperatures and pressures. Control rod worth b
and boron worth were then measured over a range of temperatures from ambient temperature to operating temperature, and over a range of boron concentrations from 1150 ppm to zero. These tests shewed control worth in good agreement with previously calculated values, and indicated that the initial reactivity of the core was slightly in excess of design criteria.
As predicted, the reactor can be shut dcwn and caintained 37. suberitical j.
at operating te=peratures by the use of the control rods alone, and the cold clean core can be maintained 57. suberitical by the addition of boric acid to the main coolant water in a concentration of 1150 parts per cillion.
tu sece of the operating coils, mechanisms some electrical grounds occurred 4/ In testing control rod drive a
which had to be return 2d to the manufacturer.
}/ Yankee stated that during core loading, there developed an unexpectedly high increase in c6nnt ra.e as additional fuel asse=blies were added. Core loading was suspended f ar several days while data was analyzed by the physicists. The prob'em was ultimately traced to geocctric effects arising q
from loading sequenco, which was thereafter changed.
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8 Measurements of the teeperature coefficient of reactivity over a range of temperatures and with varying boren concentrations confirmed the negative character of this important coefficient, and indicated that its
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value, at operating temperatures and conditions, is slightly in excess
'of that previously calculated. -Measurements of the smaller positive pressure coefficient in(_.ated agreement with prior calculations and the ficw coefficient was found to be essentially zero. Tests of the nuclear
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instrumentation used for the control of the reactor indicated excellent
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response to the changes in control rod positioning and other changes in the distribution of flux within -the core.
At t a completion of low-power testing, the turbine generator was S
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brought u i to speed and synchronized, and the initial generatica of electricity occurred on Nove=ber 10, 1960. A further series of tests was then perfor=cd as the plant was brought up in pcwer in steps of 30 MUE to 129 MUE, corresponding to 392 MRT, the caximum level authorized by the license. Plant instru=entation and control syste=s perforced in accordance with design, and the reactor regulated autcmatien11y on tecperature con-p 5'
trol with no rod motion required for small load variations throughout the power range.
Loss of load tests were perforced at 30 MWE and 60 MUE, and indicate that transient temperature and pressure limitations will not be exceeded throughout the power range, even if the reactor is not autceatically scra=ced upon loss of the-electrical load.
Initial measure-ments of the power coefficient of reactivity were made and a satisfactory m-- -
9 method of future measurements at 2000-hour intervals throughout core life was established. Measurements of radioactivity levels throughout the
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plant were carried out, and upon the addition of extra shielding at the top of the neutron shield tank all levels of radioactivity were within prescribed limits.
Tests of emergency cooling by natural circulation were carried out at 60 MRE and 120 MRE, and established that after a scram caused by loss of the main coolant pucps, adequate cooling vill be provided by natural circulation to remove decay heat frcm the core.
However,.cen--
- ms tinued circulation of cold water through the secondary side of the steam
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generators was found to increase the reactivity of the core and, although
' ne reactor will recain sub-critical during this transient, an automatic boiler feed pu=p trip is to be installed as an additional protective feature.
Excessive vibration in the shaft of the turbine-generator caused a two weeks' delay in the ccepletion of power cestin2, which was resuced on January 16, 1961 after satisfactory modifications of turbine blade rings had been cade. A full load of 120 MWE was attained on January 17. Uith cnly slight interruptions, operations continued at this power level during the required 500-hour run, which concluded on February 8,1961.
Cperations have since continued at substantially full power level except for a chutdcun in.r bruary occasioned by excessive valve stem e
Icakage, a shutdown in early April for making the required tests and ceasurements at the acc of 2,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> of core life, and a shutdown in 3/ The extra shielding was first in the form of barrels of water which have
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now been repicccd by blocks cade up of k-inch sheets of tecpered casonitc.
Each black is covered with 20-guage sheet aluminum.
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p 10 May for maintencnce on the turbine governor system.
It is the Yankee view that op2rati..g results have established a higher over-all plant efficiency than it originally predicted, with the result that a 392 MUT reactor power level has been found to correspond to gross electrical
- g pcwer level of 125 MWE.
fp A detailed description of power operations and test results to date
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is contained in the six-months' operating report as supplemented by testi-
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b cony introduced on behalf of Yankee, and confirmed by testimony of the
.sEss AEC inspector assigned to this project.
It in concluded that operation
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of the reactor has been carried out in accordance with the terns of the license, and that the nuclear characteristics and performance of the reactor have been-substantially in agreeme' t with design expcetatione and prsviesly n
LI el calculated and predicted values.
No hazards have been disclosed, either different frem or greater than those previously analyzed in the license f
application and reviewed by the Cc= mission in. connection with the is-suance of the presently outstanding license.
It is further concluded, therefore, that operation of the reactor pursuant to the outstanding license has confir=ed the safety of continued operations, subject to the is I
restrictions now in eff wet, and provides a satisfactory basis for the issuance of a per=anent 40-year operating licerse for this facility.
As indicated by the Third intermediate Decision, the purpose of
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t requiring a substantial period of operation at 392 hWT was first, to con-firm the nuclear characteristics of the reactor through actual operating a
7/ The change in the core loading sequence to avoid the geometric effects first
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s experienced as shewn,by the " unexpectedly high increase in count rate" consti-l I
tutes a variance from initial calculations, and warrants reference of such nuclear characteristics to cecpetent physics, which Ycnkee has done.
8/ Certain scre=s have occurred which were due to human error, which will Ucrrant continued alertness to avoid hazards.
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q 11 experience, and second, to provide ceasured values of important nuclear charceteristics at the design power level af the initial core in order to predict core capability and performance at higher power levels.
Of
-particular icportance in determining the capability of the core are the thereal licitations known as the " hot channel factars", which state the relationship of average heat conditions in the core to the maxieum conditions ~in the hottest channel. The principal function of the in-
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core instru=entation is to provide a means of determining flux and te=perature distributions within the core in order to provide accurate data for the calculation of the hot channell factors.
uL At the conclusion of the preliminary t esting program and the 500-bcar run at 392 MWT, Yankee and Westinghouse Electric Corporat en, the 7
nuclear designer of the plant, reanalyzed core capability and performance on the basis of experimentally determined values, to determine whether the pcwer level could be increased within the limits set by existing operating restrictions. The results of this analysis are contained in the data sub=itted as a part of the foregoing identified A=endment No. 25 to Yankee's license application.
These calculations indicate that, based on the cost extreme conditions anticipated throughout core life, the ther=al limitations in the technical specifications will not be exceeded by steady state operation at 485 MWT.
Specifically, heat flux at the point closest to burnout in the hottest channel will not exceed 50% of the burnout heat flux, as predicted by the Bettis Correlations; coolant p
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i-terperature at the exit of the hottest channel will not exceed 603 F;
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and the caximum clad surface te=perature in the hottest channel will not exceed 663 F.
In addition, all transients associated with the accidents, postulated
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in the hazards summary report, were reanalyzed at 485 MWT on the basis of operating experience to date, and the expericentally established hot channel factors.
Identification of the maxieum credible accident and the er more severe hypothetical accident remained unchanged, with conse-
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quences no more severe than those originally analyzed.
Reanalysis of the g,
- -d loss of load transient, however, has indicated the desirability of addi-
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tional protective features, authorization for which has already been given by the Cocmission's Division of Licensing and Regulation on change
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requests submitted by Yankee.
9/ These Yankee requests were approved on May 25 and June 6,1961 and include authority for installation of a vent system for the distillate accuculator tank in the radioactive waste disposal system, change in the circuitry and set points of the safety injection' system, installation of the centrol circuitry necessary to initiate a trip of the boiler feed pu ps in the event of a reactor scram above 15 tm electric, addition of a scram initiation circuit which would provide a reactoi scram in the event of high water level in the pressu;izer, assumption of a dilution factor of 1000 for radioactive noble fission gasses, clarification of the use of the conitor in the incinerator stack and caintenance of the monitor in continucus service, change in the relative position of a motor operated valve and manually operated valve. These changes were guthorized on the basis that none of the foregoing present significant hazard censiderations not described or icplicit in the license application as amended to January 12, 1961, and that there h reasonable assurance that the heal.h and safety of the public will not he endangered by operation of the n sclear facility as thus codt!!.2d. The scope of thi: authority for change may be limited sece-yhat by Yankee's representation that for instance, in the course of loss of locd transient tests, the regative temperature transient drop in temperature a
following the scram, "was more severe than had been calculated in the course of design work and it. the accident analysis in the license application."
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13 Based on the foregoing, it is concluded that authorization may properly be given to operation of the reactor at a steady state pcwcr level of 485 MRIs A revision of the technical specifications was submitted by Yankee I
which el*minates superseded provisions relating to initial start-up and j
testing and in addition makes certain revisions to correspond with change authorizations requested by Yankee,and reviewed by the Division of Licensing
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[i::p and Regulation of the Commission and the Advisory Committee on Reactor L
Safeguards. The proposed re.ision of the technical specifications was concurred in by the AEC Staff and will be incorporated in the amended license authorized by this decision. The amended license will include
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reporting requirements suitable for a permanent operating license.
On May 4,1961 Yankee filed a motion requesting the Commission to
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en;nr an order authorizing the Presiding Officer, in his discretion, to provide that any intercediate decision and order for the issuance of an amended license in this proceeding might beccce effective itmediately upon issuance, subjett to later review by the Cecmission upon exceptions l5 or on its owe. motion. Yankee indicated that it desired to have the order l '-
in this proceeding become effective prior to the expiration of the period for Cecmission review in order to establish July 1,1961 as the date mark-p p
ing the end of the period of construction and test operations and the
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co==encement of regular operation of the plant for purposes of its ac-counting, power contracts and financial docu=ents; and, further, in order
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to make available the additional generating capacity of the plant at the earliest practicable date.
On June 12, 1961, the Commission issued its crder in this docket responsive to the motion filed by Yankee. Upon the basis of this entire record, and under the circumstances, it appears.
reasonable to provide for the ismediate effectiveness of this intermediate decision, subject to later review by the Commission upcn the teres provided i.-
in the foregoing order.
In addition to the foregoing, which constitutes findings and con -
clusions, and upon consideration of the record in this proceeding, in-ciuding testimony, exhibits and the submissions c# the parties, it is found and conclud'ed that:
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1.
Yankee Atomic Electric Company, a Massachusetts. corporation with its principal office at 441 Stuart Street, Boston, Massachusetts, is the holder of Facility License No. DPR-3, issued on July 9, 1960 and amended on July 29, 1960 and January 12, 1961, author-izing operation of a pressurized water' reactor for use in the generation of electricity at a nuclear power plant situated in Rowe, Massachusetts. The reactor is a utilization facility'as defined in the Atomic Energy Act of 1954, as amended, and the foregoing license for its operation has been granted pursuant to section 104(b) of the Act.
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The reactor has heretofore bees.,perated at steady state power I
levels of 392 MWT in accordance with the ter=s of the foregoing l
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On the basis of operations to date, as reported to the Ce==ission in an operation repert filed by Yankee dated Febru-ary 13, 1961 and supplemented by testimony in this proceeding, the processes. co be performed, the operating procedures, the facility and equipment, the use cf the facility and the technical' specifications, collectively, provide reasonable assurance that the health and safety of the public will not be endangered by operation of the reactor at steady state power icvels up.to 485 MWT.
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3.
Facility License No.~DPR-3, heretofore issued on a provisional
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basis, should be further amended, pursuant to section 50.56 of the Ccemission's regulations, to provide for the continued operation of the reactor upon the terms prescribed herein, the license as so amended to expire en a date 40 years af ter the date of the Construction Permit No. CPPR-5, namely, on November 4, 1997.
WHEREFORE, IT IS ORDERED, subject to the review procedures provided for this proceeding by the Co= mission, and in accordance with the Atomic Energy Act, as amended, and the Rules and Regulations of the Commission:
A.
The Division of Licensing and Regulation chall issue to Yankee Atemic Electric Cc=pany an amended license pursuant to Section 104(b) of the Atcmic Energy Act of 1954, as amended, authorizing the con--
tinued operation of the foregoing reactor, said amended license
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L 16 to be in the form attached as Exhibit A hereto.
'B.
In accordance with the Comissior '.s Order in this docket dated June 12, 1961, this Intermediate Decision and Order shall become effective imediately upon issuance, subject to (1) the filing and consideration of a petition for review, if any, pursuant to Sections 2.751 and 2.752 of the Cocmission's Rules of Practice, and (2) such further order as the Comission resy enter upon its own motion within forty-five (45) days af ter the issuance of such intermediate decision and order: provided, however. That, in the absence of any further Cor:raission order pursuant to the foregoing, the intermediate decision and order shall become k
the final decision and order of the Comission at the end of t:
such forty-five day period.
l Samuel W. Jensch Presiding Officer ir
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Issued:
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June 20, 1961 f
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U Ger=antown, Maryland I,
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