ML17037C355
| ML17037C355 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 06/06/1968 |
| From: | Morris P US Atomic Energy Commission (AEC) |
| To: | Pratt M Niagara Mohawk Power Corp |
| References | |
| Download: ML17037C355 (24) | |
Text
Docket No'. 50-220 Niagara Mohawk Power Corporation 300 Erie Boulevard West
- Syracuse, Nev York 13202 Attentioh:
Mr. Minot H. Pratt Vice President and Executive Engineer JUN 6
19SS bcc:
Distribution:
AEC Pub.
Doc.
Qgyn Torma1.
Suppl..
REG Reading DRL Reading RPB-2 Reading Orig: VStello M. M. Mann R. S.
Boyd L. Kornblith (2)
H. Steele (2)
J. Buchanan, ORNL C. K. Beck Gentlemen:
This refers. to Amendment No. 2, dated June 1, 196'p, to your appli-cation'for a construction permit and operating license for the Nine Mile Point Nuclear Station located in the tatm of Scriba, New York.
During meetings held on April 10 and 11, 1968, we discussed several technical aspects of the facility design with your representatives and indicated that additional information would be necessary to continue our review.
This information concerns seismic design, transient analysis and accident design considerations.
A list of specific comments illustrating the kind of information needed is enclos'ed.
We will continue our review of the foregoing matters upon receipt of the additional information.
We will be available to discuss and clarify any of the specific comments.
Sincerely yours, P~ Origiogl-QiilEd bg'~getev QJPOrnS
'eter A. Morris, Director Division of Reactor Licensing
Enclosure:
Request for Additional Information cc:
Mr. Arvin E. Upton, Esquire LeBoeuf, Lamb, Leiby 8e MacRae OFFICE ~
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ADDXTXONAL IIGQRMATION REQUIRED NINE MILE POXNT STATION
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NIAGARA MOHA>"K PO>lER CORPORATION DOCKET NO. 50-220 T.
GEi(CABAL Your application defines Class X, Class XI and Class XXX structures and components as follows:
Class I Structures and Com onents-Structures and components whose failure could cause pignificant release of radioactivity or which are vital to safe shutdown an];isolation of the reactor.
Class XX Structures and Com onents-Structures and components which are important to reactor operation but are not essential to safe shutdown or isolation, and could not result in substantial release of radioactive materials.
Class XEX Structures and Com onents-Structures and components tgat are not essential for safe shutdown and isolation of the reactor and whose failure will not result in significant release of radioactive materials.
Define and describe the bases fear the limits of the "release of radioactive materials" associated with each of these definitions.
2.
Provide complete Listp of Class I and Class IX structures and
- systems, of structures constructed of elements of more than one
- class, apd of Class I equipment housed in, adJacent to, or supported by a Class XI or Class XII structure.
Describe the design techniques E
used for Class I md Class XI structures.,
For Class XI structures and for structures consisting in whole or in part of Class I elements, state the criteria used to determine the 1
design basis load combinatiopp to be considered and the allowable str'esses or the allowable deformations for each design basis load r
combination.
4,
/tate the design basis load combinations, allowable stresses and/or allowable deformations, and calculated deformations for.each structure, system or component consisting in whole or in part of Plass I elements.
5, Discuss the seismic exposure assumptions and the criteria relating to spectra, amplification, damping and other appropriate factors used in the design of the plass XI structures and for structures consisting in whole or in part of Class I elements.
Provide justifica-tion for the damping levels assumed for the stack.
6.
The Preliminary Hazards Sunurary Heport stated that Class II structures will be designed for a ground motion of the O.llg design earthquake.
Xt is not qlear that this 'criterion was followed rigorously; pLease clarify.
7, Describe the present capability of the plant to withstand a tornado.
8.
Discuss the basis fbr the deyelopment of the acceleration response spectra shown in Plate C-22 of the First Supplement to the Preliminary Hazards Summary Beport.
Vere these spectra used in all dynamic analyses?
What is the basis for the large."saw tooth" variation in the range of 0.1 to 0.3 seconds for 0 percent critical damping?
Vhat is Che basis for the sharp change in acceleration at a period of about 0.12 seconds in all the spectra?
9, For all systems, components~
or structures
- analyzed, were the allowable values for stresses resulting from the combination of I'perating loads and earthquakes increased by 33 1/3 percent in accordance with code practices?
10.
Describe the method use/
go combine seismic stresses with the stresses caused by operating an/ other loads.
11.
Vas the ratio of vertical to horizontal excitation equal to one-half throughout the analyses in all cases?
V 12.
For Chose cases analyzed using the reserve energy technique, what was the maximum level of deformation that was permitted in the analysis?
13, Discuss the design criteria used Co assure that the function of any structure will not be lost because adjacent structures strike each other under seismic excitat"'on.
Provide e timates (with bases) of the magnitude I
of relative motions of adjacent structures and a discussion of the provisions made to ensure the continued integrity of qonnections (e.g., piping) between buildings.
Xn view of Che shaly laminations et the site, discuss the permanent relative displacements that can occur and. the design features that ensure required performance under these conditions.
IX, STRUCTURES i
l.
Describe the crasis for the selection of the acceleration factors I
of 0.20g horfsontal and O,lOg vertical for the control room components<
Vere these factors also used for essential, instrumentation, controls protection : ystem and electrical system components in the control room?" Vhat acceleration facto s were used fop these components at other locations?
2,.
Describe thy portion of the intake structure designed as a Class I structure.
3.
Evaluate the effect of wind speed and the shape of the reactor Quilding on tge validity of estimated leakage from the reactor building and on the validity of the reactor building leakage tests.:
4.
Evaluate the consequences of a stack failure in which portions of the stack strike the plant.
III. REACTOR l.
Describe the assumptiors, method of calculation and uncertainty in the prediction of the beginning of life and end of life power coefficients.
2.
Describe the model and assumptions used to account for reactivity changes due to void changes caused by rapid isolation of reactor coolant system (e.g., tur'oine trip without bypass).
3.
Describe the spacer pellet ad)scent to the fuel rpd spacers in l
the center fuel pin of each fuel bundle.
4.
Vhat is the expeqCed life of the control rod if'ater leaks into the B~C; what effect would it have on dimensions of the cont ol rod?
Specify the reactor components whichmst maintain their functional capabilities to assure safe shutdown of the reactor.
For each such component describe:
(a) the design basis load combinations (b) the expected stress and deformation (c) the stress and deformations at which the component is unable to function (d) the margin of; safety (e) the effects of irradiation on material properties and deformation limits.
6.
Confirm that the integrity analysis for the rea"tor vessel internals
~
is identical to Amendment 12 to Docket No. 50-219, Oyster Creek Nuclear Power Plant, Unit No. 1, Jersey Central Power and Light Company.
'(.
Discuss the effects of vibration during normal operation on the components inside the reactor vessel.
Describe design features to prevent or limit vibration.
Describe tests and instrumentation to determine if unexpected vibration is present.
XV.
CONTAXRKFi'.
Establish the compatibility of dynamic deforrpations (for the earthquake and the combined accident plus earthquake conditions) occurring in the dryweLL, thetorus and the connecting vents, including expansion joints.
No positive anchorage system appears to be provided between the interior concrete structure supporting the reactor, the lower part of the drywell sheLL,and the concrete foundation under the dry welL.
The dynamic characteristics of these three structures are very different and their
'esponse to a seismic disturbance will be dissimilar.
Xn view of this provide a discussion of the following:
a.
The validityfor the assumption that the three structures are rigidly connected at the foundation level.
Xt may be
that differential sliding of the structures, which may rotate about the common cpnter of rotation
( center of the spherical part of the dry well) will occur and rupture the bond between the steel and the concrete,
- b. If such sliding occurs, what are the consequences from the point of view of dynamic stresses and strains for the three l
4 structures?
- c. If the bond between the'teel and the concrete is broke cap corrosion of the steel shell occurs Consider~ in this discus-sion the effect of the temperature
- gradient, and of the resulting thermal expansion of the shell, on the bond between steel and concrete.
d.
Provide diagrams for each of the three structures indicating the earthquake accelerations at different levels, the over-turning, or bending moments and. the shears, and the relative 1
displacements.
- e. If the three structures men ioned above are interconnected at the bottom, provide a discussion of the design of the installed anchors.
2.
Provide a detailed discussion of the design bases for the gap between the primary containment and tne concrete shielding.
Discuss the construction technique used to establish the gap and the materials involved in the procedure.
How is the gap to be ventilated and drainedf
3.
Evaluate the effect of debris in the air gap betw'een the drywel3.
and the shielding on the integrity of the containment under accident conditions.
4.
Mhat portion of the drywe3.1 air gap can be insp cted?
5.
Provide analyses of the deformation of the dry well wall due to jet forces acting on the wall or on elements connected Co the wall which show that such forces pill not result in breaching of the containment, This analysis should inc3.ude an evaluation of the effect of Jets or missiles impinging on the containment at locations opposite steel flanges at Che form joints that are close to the surface of the concrete.
Hhat are the applicable stress and strain criteria?
ls Chere any possibility of jets hitting the wall og the torus of the pressure suppression chamber?
Ue understand that Chicago Bridge and Xron Company conducted tests simulating the effect of the jet forces on the drywell stee3. shell.
Discuss the reliability of the results of these tests as ayp3.ied to the actual conditions existing during an incident, considering that the dynamic effect of the jet and the the mal effect of the hot fluid on the steel plates have been neglected.
6.
Provide a more detailed description of~ and the design basis for~
the containment penetrations, particularly those for high temperature lines.
3:nclude (a) the methods of stress analysis employed for Che penetrations, both large and small, to assure their continued integrity under combined normal, seismic and accident loads, (b) the leak test, capability for the penetratiom, and (c) fatigue design
of 'the penetrations.
include material specifications, MDTT qonsiderations, and applicable codes.
7, Describe the effect of jet and reaction loads on the integrity of containment penetra$ ions.
8, Describe the effect of the loads on containment check valves on the integrity of the containment for loads produced from line breaks that occur outside of the containment.
9.
State the design criteqia for the containment valves applicable to insuring their operation during and following an earthquake.
10.
Discuss the extent to which post-accident containment flooding has been considereP in the structural design of the containment vessel.
Xf venting systems have been incorporated into the design, provide an evaluation of the selected concept.
Xndicate the design criteria that apply to seismic forces in combination with a flooded containment and the corresponding limiting stress levels and deformations in the drywell, in the vents, and in the torus (and its supports).
Discuss V
the water temperature and the required NDTT.
11.
For each load combination on the containment, discuss how the loads are shared in the containment supports, 12, The foundation of the containment rests on bedrock described as Substantial Oswego Sandstone.
Discuss:
e.
The construction procedure used to avoid damage to rock during the time interval between excavating and
'll installing of foundations.
b.
The shape of the excavation under the containment, Has the rock directly uqder the dry well foundation been excavated to the same level as the rock under the pressure suppression chamber or notV
I
~
c.
The 'behavior og shaly laminations from the point of view of accelerated weathering during construction.
d.
Supporting evidence for the statement that th. behavior of Oswego sandstone under dynamic loading is similar to tQat of sound rock, despite the lenticular nature of the rock and the, presence of cross-bedding and shaly laminations.
How has this pondition been taken care of in dynamic analysis of the structuref What value of damping has been used?
lj.
Provide a detailed discussion of the primary containment pneumatic testing incldding the.extent to which the acceptance test pressure stress loadings simulates design basis accident loadings and combinations of accident and earthouake loadings.
14.
Provide a detailed discussion of the primary containment leakage tests.
Describe the supporting bases for the tests and include a detailed description of test procedures and test results.
ln respect to the strength and leak rate test of the drywell and pressure suppression system, discuss the following:
a.
How was the drywell and the torus supported during these tests'f on temporary supports, describe the type used and provisions made for removal of the temporary supports'fter the tests.
Has,local overstressing of tPe steel plates been avoided' b.
The lower part of the drywell shell is sandwiched between the concrete foundation under it and the slab supporting the interior concrete structure; it will therefore be impossible to inspect this part of the steel shell after the construction is completed.
Has the soap bubble test been
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I extepded at this location to the full area of the steel plates or only to the welded seams?
15.
Provide information to support the claim that the proposed test methods can demonstrate the secopdary containment building's I
capability to maintaiq a negative pressure under various environ-mental conditions.
V.
REACTOR AUXILXARYAND EMERGENCY SYSTEMS 1.
piscuss the release of radioactive material from the components stored l
)he fuel storage pool that can result from heavy obJects (e.g., fuel sh$ pping cask) falling upon fuel stored in the pool.
Describe the I
operating restraints or design features which reduce the probability of this type of accident.
2.
Discuss the release of radioactive material that may result if the fully loaded fuel'shipping cask were to drop from the maximum height (80')
h to which it is raised during fuel transfer operations.
3.
Discuss the consequences to thy valve operations that occur if the instrument air supply fails.
4.
Discuss how the release of radioactive material during refueling or fuel shipping accidents is detected.
How is safety action initiated for these releases?
Vi.
APPENDXX E - SAFETY ANALYSIS 1.
Section 3.7 Valve Operation a.
Describe the interaction of reactivity effects that determine the neutron flux vs time characteristic.
o.
identify the parameters that determine the magnitudes of the neutron flux peaks, the number of neutron flux peaks and the
0 decqy of the neutron flux indicated for this transient.
c.
Describe the distribution throughout the core of the energy released during this transient.
2.
Section 3.11 Turbine Trip with Failure of Bypass System a.
Provide curves of reactivity changes vs time for the I~
four (4) seconds following the initiation of the transient, Provide separate curves for reactivity changes due to each of the following; void changes, control rod insertioq, and Doppler effect.
b.
Describe the changes in power density at the locat'on of void
c.
Mhat is the total energy stored in thecore while the neutron fl'~ is greater than its initial value prior to occurrence of the transient.
d.
'What is the maxim~ UO2 temperature during this transient7 e.
Describe the effects on items a thru d above for this transient occurring at the end of a fuel cycle.
What is the gap between the Kr clad and UO pellet prior to the transient and at the 2
time of maximum UO temperature after initiation of the transientV 2
4