ML19256F854

Irep - Initial Plant Study. Attempts to Develope Assessment of B&W Reactors to Identify Risk Impacting Sequences Re Reactor Safety Study & Preliminarily Identify Possibly Impacted by Design Changes

ML19256F854
Person / Time
Site:	Crane, Crystal River
Issue date:	10/25/1979
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML19256F850	List: ML19256F849 ML19256F851 ML19256F853 ML19256F854
References
NUDOCS 7912260348
Download: ML19256F854 (4)

Text

IREP - INITIAL PLAKT STUDY _

We have attemoted to develop a general framewo An abs:1ute de:et ination of sepuences relative to the Reactor Safety Study.We have selectec Crystal T e at:hitect-engineer risk is not intended.

operated by Fl:ri.da Power Corporation, for analysis.for thi It began cocnercial operation in March 1977.

The project, as presented in Figure 1, will require the following task A survey of the LER files as now established in 0700. and A0 report identify well as the Sandia and Fluor-Zion systems intera :icns studies to 1.

This survey should parallel construction of syst d into the trees sin:e it will ensure that actual experien:e is incorporate

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assessments performed.

See:jfic Event trees for loss-of-coolant accidents and tra 2.

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d will water transient tree which incorporates exnerience at B&W p an s anE explore tne post-TM' modifications. standing :ne numan couplin sequence level.

They will Fault trees for the key systems identified in the eve I3.

Hr.an errors viii be included as well and electric power considerations.as the abili y of the operator t Our preliminary opinion is that simplified faul: auxiliary feedwater and se:e i

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high pressure emergency core cooling in :ne inje:: ion and rec rcu a tne following systecs:

i modes, low pressure emergency core cooling in b:tn injection an limited m0 des, containment spray and containment heat removal systems stucy of loss of AC power, considering the emergency ciesei generators, witn limited analysis of high volt Separate fault trees wiii probably be required for ECCS and AFWS initiation logic and the system trees must include the centr yard faults.

from auxiliary systems such as instrument air, ventilation, componen cooling, etc., and controi-incuced failures.

This basis will will be permitted provided a written basis is provioed.

is present the rationale why no coupling of cutsets or event sequenc expectes from further development of the tree.

An investigation of the adequacy of high Oressure-low pressur 4

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'.alysis Of the physical enenomena ass :ia.e:De magnitu e Of "flea ne Cor. ainment.

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To conduct a program of this magnitude in a short time ceriod, delays assoc '

iated with acquiring and transferring infennation =us be =inimiced. Optimally, the event tree and fault tree analysts should share a : ant:n locatica during As the fault trees pr:gress be!>w the

ne initial portion of the project.

p logic, howev'er, the analysts should be located at r near the site with inmediate access to as-built drawings and proce:ures as well as a representative This will per=i: verifi:stien of en;ineering of the plant operations staff.

and procedural details and will minimice informati:n transfer and print re-Access should also be arranged between the fault tree analysts produ: tion.

at the site, the remaining team in Bethesda, the architect-engineer, and the vendor.

In addition to basic plant da'ta, deterministic. calculations may be required to This may understand the behavior of the plant under off-normal concitions.

also involve real-time simulation at an appropriate simulator to the extent The arrangements with the vend:r should cover this possibility and possible.

it may be desirable to have co.nfirmatory calcula:icns made by one of the NRC c:ntractors on a selected basis I638 302

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ENCLOSURE 3 PRELIMINARY IDENTIFICATION OF SYSTEMS AND COMPONENTS THA BY DESIGN CHANGES HPI System EFW System DHR System CFT System RCS Pressure Control System Makeup / Letdown System SG Pressure Control System Steam Generator Pressurizer Quench Tank Control Room Layout RCS Piping 1638 304

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