ML20198G126
| ML20198G126 | |
| Person / Time | |
|---|---|
| Site: | Washington Public Power Supply System |
| Issue date: | 11/11/1974 |
| From: | Faulkner H US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Maccary R US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| CON-WNP-1012 NUDOCS 8605290246 | |
| Download: ML20198G126 (11) | |
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NOV 111974
. d All Engineering Personnel k '
! TIIRU R. R. Maccary, Assistant Director
! for Engineering, Dirsetorate of Licensin !
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WRITING STYLE IN SAFETY EVALUATION REPORTS i At a recent RP-TR management meeting, it was agreed that in writing future SER's, the first person and the active tense should be used. For example, we should use "We reviewed this" rather than "The Regulatory staff review-ed this", and "We conclude" rather than "It is the staff's conclusion".
Attachod is a portion of an SER which was prepared by SE3 for WPPSS Uumber
- 1. I have marked it according to these new instructions so that you can use it for guidance. Also, attached is a copy of General Guidance on Terminology which was prepared by Reactor Projects. It provides some help-ful direction toward improving the readability of our routine reports and correspondence.
', Oridac! Fim ,
- y llower:1 J. F..:G.v:r H. J. Paulkner, Technical Coordinator for Engineering Directorate of Licensing
, cc: F. Schroeder, L i
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NUCLEAR PROJECT i:0.1 DOCKET f'0. 50-460 STRUCTURAL ENGINEERU:G CRANCll SAFETY EVALUATION REPORT 3.3 LIIND AND TORNAD3 LOADINGS 3.3.1 Wind Loadings All the plant seismic Category I structures listed in Table 2.2.2 of Section 3.2.1 of the PSAR will be designed to withstand the effects of the design wind. Seismic Category I systems and con-ponents which are housed within these structures will therchy be protected from its effects. For seismic Category I syster,s i:nd components exposed to the wind, they will be designed to wi'.h:to.d its effects. ,
The design wind specified for the plant has a velocity of 100 cph at an elevation of 30 feet above grade. This wind velocity is greater than the maximum velocity of 85 mph deterniined on the basis of ASCE paper No. 3269 for a 100 year period of recm n Chapter 2 of this report presents the basis for establishing thi design wind paraueter.
' The velocity profile, the conversion of wind velocity into equivalent pressure load and the computation of the average wind pressure, on projected areas of a structure are in accordance wiL8i ASCE Paper No. 3269. A gust factor of 1.1 is used in determining all vind loads ASCE Paper Ng 2gghasbeenusedinpreviousapplicaticns, a accep r use*
A A 3.3.2 Tornado Loadings All Category I structures will be designed to withstcnd torn::da effects. Therefore all safety-related systems and components located within these structures will be protected from these ef fects.
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t The design tornado criteria confor:u to AEC Regulatory Guide 1.76 for Region III. The tornado has a tangential velocity of 193 r:ph, a translational velocity of 50 mph and an associated pressure drop of 1.5 psi at the rate of 0.6 psi per second. In additien an appropriate spectrum of tornado generated aissiles is also postulated.
The tornado velocities will be convarted into equivalent pressures on the structures on the basis of ASCE Paper flo. 3269 by using a resultant velocity of 240 mph. The equivalent pressures thus obtained together with the pressure drop and the tornado missile impact will be taken into consideration in the design of Category I structures. As a result the tornado loads will. include uind effects, associated pressure drop and the tornado-generated missile irapact load. The tornado loads will be combined with other applicable loads as will be discussed in Section 3.8 of this report.
' The possible failure of non-Category I structures which are in I the vicinity of Category I structures and are not d2 signed to resist i tornado loads will be taken into consideration in the design of
'A Category I structures.
l 3.3.3 Concl6sion i
w %.Qak It is :
- =:udc that the procedures to be used in deter-j mining the wind and tornado loadings on Category I structures I provide a reasonably conservative basis for engineering design of these structures and are therefore acceptable. The use of these 4
procedures provides reasonable assurance that, in the event of a design wind or a design tornado, the integrity of these structures will not be impaired. Consequently safety-related systems and components located within these structures are adequately protected and will perform their intended safety functions if needed. Con-formance with these procedures is an acceptable basis for satisfying
in part the requirement of general design criteria #2.
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- 3. 4 UATrk,JEVEL (FLOOD) DESIGil The plant finisled grade elevation around the conteira.ent and general services building will be EL.456.0 which is well above the flood clevation of 424.5 feet MSL used in the design of all Category I structures. A detailed discussion on the establishment of the floed elevation is contained in Section 2.4 of this report.
Since the lower portions of the Category I structures are below the flood elevation, all Category I structures are designed to resist the hydrostatic forces and checked for uplift or overturning considering the buoyant forces. They will be made watertight through the use of water-tight concrete walls and foundation mats covered with waterproofing nombrane, and waterstops and sealants in wall joints. In addition accesses to all structures will be located above the flood level.
Wpc.av O-It u :::id: that this procedure of design for protection against the effects of water enc flood is acceptable. It provides reesce ble essur-
- ance that in the event of floods, the integrity of Categorp I struc-
. tures will not be imoaired. Therefore Category I systems and components located within these structures are adequately protected and will perfom their intended safety function if needed. Conformance with this design procedure constituteran acceptable basis for satisfying in part the requirements of general design critorion #2.
- 3. 5 MISSILE PROTECTI0il 15.1 Mi ssil o Bary_j,er_S.
Structures, shields and barriers that will be designed to withstand the effects of the various postulated missiles are listed in Table 3.5-1 of the PSAR. The missiles that can potentially impact these structures, shicids and barriers are classified into missiles internal to the containment and tornado-generated missiles. They are identified respectively in Tables 3.5-2 and 3.5-3.
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3.5.2 l'issile Selection To be written by APCSA 3.5.3 Selected' Missiles To be written by AAB 3.5.4 Barrier Design procedure.
The structures, shields and barriers will be designed to withstcnd the local effects and overall effects of missile impact.
The most significant local effect of missile impact is perforation of the missile. The concrete barrier thickness required to prevent perforation will be datermined by using the Modified Petry formula.
In addition where spalling of concrete might be cor1sidered a hazard to personnel or safety-related equipment, the design of the barrier will preclude spalling or additional protection will be provided.
The overall structural response of the barrier due to missile impact will be determined by using established methods of impactive djm.As analysis. .In the analysis various simplifying yet conservative assumptions are to be made.
J The missile impact load will be combined with other applicable loads as will be discussed in Section 3.8 of this report, r f
3.5.5 Conclusions wp E,. .n ,
pI . ? r cc c'"ded tNat the design procedures to be used to determine !
- the effects of missile impact on structures, shields or barriers are f acceptable. These procedures will provide reasonable assurance thct .
the structures, shields or barriers can resist the effects of missile impact without compromising their integrity. Safety-related systems and components located within these structures or behind these
- shields or barriers are, therefore adequately protected.Conforn:nce with these procedures is an acceptable basis for satisfying in p:rt the requirements of general design criteria #2 and #4.
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i ENCLOSURE 2 GENERAL GUIDANCE ON TERMINOLOGY 9
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- i. ABBREVIATIONS To avoid confusion - de not abbreviate at any time.
- 1. REFERENCE TO ITEMS When referring to an item in the list or in a prior list use the word " item" rather than " question" or " request".
C. STYLE AND USAGE The following is a list, in alphabctical order, of sone words and phrases which are frequently misused or which should be avoided.
A few comments and admonitions regarding matters of style and composition are also included. This list is modified slightly from that prepared by F. Schroeder in 1970 for guidance in preparing reports.
adequate, acceptable " Adequate" connotes " barely suf ficient". In most cases we should conclude that a design feature is " acceptable".
adjectives and adverbs - In most cases, words like "very," " fully,"
" comprehensive," " detailed," " extensive,"
" clearly," and " essentially" cause more trouble than they are worth. Make sure they are needed and that they express the correct intent.
affect, effect "Af fect," a verb, means "to influence." "Effect,"
as a verb means "to bring about," or " accomplish;"
as a noun "effect" means " result."
applicant pronouns - In our lists, use the personal pronouns when referring to the applicant (he, they).
as to whether "Whether" is suf ficient.
as well as - Use "and" unless emphasis is required.
bases - Plural, basis is singular.
helieve - Avoid the use of "we believe" or "we feel." Although many of our conclusions are matters of judgment, few should be matters of faith or intuition. Since the purpose of most of our reports is to present the results of our evaluations, in many cases these clauses are not necessary. In presenting a significant conclusion it is preferabic to say "we conclude" or "we find." On rare occasions, "we believe" or "in our opinion" may be necessary to provide qualification or contrast.
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C. STYLE AND USACE (continued) comparative review "We compared" is better than "we performed a comparative review."
compare (comparison) - To " compare" things is to bring them together in order to note points of likeness or of dif ference.
In this sense it is followed by "with." "He compared Washington with Paris" would mean that he considered vcrious aspcces of both cities with a view to pointing out wherein they dif fered and wherein they were alike. To " compare to" means to represent as similar. "He compared Washington to Paris" would mean that he found many things in Washington which, when taken together, made him feel that the City of Washington was much like the City of Paris. In our work " compare with" is almost always the correct usage.
complement - Don't confuse with compliment.
compound nouns - Avoid the use of long strings of adjectives pre-ceding a noun to create " German-style" compound nouns Use prepositional phrases instead.
For example: "The low reactor coolant system pressure ECCS initiation signal" can be replaced by "the ECCS initiation signal resulting from low pressure in the reactor coolant system."
criteria - Plural, criterion is singular.
data - plural, datum is singular.
design basis accidents - In current usage, several design basis accidents (DBS's) are evaluated, fle do not identify a single DBA as done with the old concept of a " maximum credible accident."
different than - One thing differs from another, hence "different from" not "different than."
discover, determine, reveal " Discover" presupposes exploration, investigation, or chance encounter and always implies the previous existence of what becomes known. " Determine" emphasizes the intent to establish the facts definitely or precisely. " Reveal" suggests public or dramatic dis-closure of what has been concealed. In our work " determine" is usually the preferred usage.
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i C. STYLE AND USdGE (continued) 3 Doppler - An adjective modifying, for example, " coefficient" or "effect," unless for some reason you are talking about the man. I due to "Because of" or "owing to" are usually preferred. In correct use "due to" is-related as predicate or modifier to a particular noun, e.g. : "This invention is due to Edison;" " damage due to fires."
dynamic consultant - Do not use.
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e.g., i.e. These/ two ' abbreviations have dif ferent meanings and should not be corfused. The first is an abbreviation for the Latin " exempli gratia," "for example;" the second for "id est," "that is."
etc. - Avoid using as a euphemism for "There must be others, but I can't think of'any.", At the end of a list introduced by "such as," "for example,"'
or any similar expression, "etc." '
is incorrect.
farther, further " Farther" refers to distance, "further" to time or quantity. You pursue a subject "further."
feel - See "believe."
finalize - Do not use.
identical, similar, same " Identical" implies absolute agreement in 'all details. "Similar" imp W e resemblance. "Same" means resembling in every relevant resp et. Because " identical" is usually too strong, aca "r(cil r" carries the suggestion that there may be import,an f,tf; ences not readily apparent, in most cases the preferted us... for comparinonn in our work is "the same."
imply, infer - The writer " implies;" the readet' " infers."
include, but not limited to - Avoid this crutch. Specify what-should be included. If you can't think of anything else that is needed, the applicant probably can't either. _
less'. fewer "Less" refers to quantity, " fewer" to number. Fewer pumps provide less flow.
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t C. STYLE AND USAGE (continued) maximize, minimize - Avoid use of these words when what is nennt la
" increase" or " reduce."
numerals in parentheses - Avoid the legalistic style of providing unnecessary redundancy by repeating numbers in words and numerals; e.g., "three (3) pumps." For our work spell out the numbers in words in all cases; e.g., "three pumps", except on tabits & enclosed figures they may provide.
obviously, of course, it is clear - Avoid use of such words and phrases. They are usually unncessary and are sometimes insulting to the reader.
paragraphs - A paragraph may be of any length - a single short sentence or a passage of great duration. As an aid to the reader, a subject should be divided into topics, each of which should be made the subject of a paragraph. The beginning of each paragraph is a signal to the reader that a new step in the development of the subject has been reached.
As a rule, begin each paragraph either with a sentence that suggests the topic, or with a sentence that helps the transition. When you edit your draf t, check carefully to see that your paragraphing is logical and helpful.
passive voice - Avoid overusa. The active voice is usually more direct and more vigorous. "We reviewed the design of . . . ."
is preferable to "The design of . . . was reviewed by us."
phenomena - Plural, phenomenon is singular.
principal - Don' t confuse with principle.
i redundant - Avoid overuse, particularly when all that is mean is "another" or "a second."
requirements - Use "our requirements" with care. In general, use only with reference to published rules, criteria, guides or well-known l precedents.
respectively - Although the construction, "x and y, for a and b respectively" can be useful, it also can be confusing in long complex sentences, and is frequently unnecessary in short sentences.
shutdown - An adjective, the verb is two words.
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s, C. STYLE AND USAGE (continued)_
singular-plural combinations - Avoid the legalistic style of providing alternate forms of a word when you are not sure whether it should be singular or plural; e.g., " describe the model(s) uded." In Such C&ses the plural form iS uSually acceptable.
uncovery - Use " prevent the core from becoming uncovered" or better yet " prevent loss of water from the core" rather than " prevent core uncovery."
while - Avoid th'e indiscriminate use of "while" for "and," "but,"
and "although." Although such use is allowable., it can sometimes lead to confusion. In the strictest sense "while" means "during the time that."
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