Regulatory Guide

KSC increases the failure rates of components from causes such as earthquake, fiic. flooding, tornado, erroneous maintenance or inis-sp>ecifying the operating cnvironmcni. [ nvironmental qualification (EQ) of equipment, specified by Regulatory Guide 1.97, as.surcs ihc operation of instruments in an accident environment. Similar qualification is required for a tiesi uu-basis earthquake. 

PRISIM embodies the IREP model of Arkansas 1. It includes extensive grapitivs of. simplified flow diagrams and relevant operating history from LERs (Licensee Event Reports required by Regulatory Guide 1.16) The plant model consists of 500 cutsets truncated by probabilities determined from normal operation. 

Regulatory Guide 1.145 provides corrections to the sigmas to correct for the c ffects of wind meander at low windspeed - much the same effect as achieved in the CRACIT code. Figure 8.3-1, taken from this guide, shows how the horizontal dispersion coefficient varies with distance from the source. To calculate x/Q (the fractional attenuation) use formula (8.3-1) for a particular distance from the plant, say 1 km. 

Regulatory Guide 1.113 provides procedures for estimating the aquatic transport of accidental nd routine releases from nuclear reactors. Because these methods are complex and have not been included in PSAs, they are not discussed. 

Suppose an interstate highway passes 1 km perpendicular distance from a nuclear power plant control room air intake on which 10 trucks/day pass carrying 10 tons bf chlorine each. Assume the probability of truck accident is constant at l.OE-8/mi, but if an accident occurs, the full cargo is released and the chlorine flashes to a gas. Assume that the winds are isotropically distributed with mean values of 5 mph and Pasquill "F" stability class. What is the probability of exceeding Regulatory Guide 1-78 criteria for chlorine of 45 mg/m (15 ppm). 

NRC (1977). U.S. Nuclear Regulatory Commission. Calculation of Annual Doses to Man from Routine Releases of Reactor Effluents for the Purpose of Evaluating Compliance with 10 CFR Part 50, Appendix I, Regulatory Guide 1.109, Rev. 1 (U.S. Nuclear Regulatory Commission, Washington). 

U.S. Nuclear Regulatory Commission (1977) Calculation of annual doses to man from routine releases of reactor effluents. Regulatory Guide 1.109, Rev.l. 

NRC (1978), Evaluation of Explosions Postulated to Occur on Transportation Routes Near Nuclear Power Plants, Regulatory Guide 1.91, February. 

NRC (2001), Assumptions for Evaluating the Habitability of a Nuclear Power Plant Control Room During a Postulated Hazardous Chemical Release, Regulatory Guide 1.78, December. 

According to USNRC Regulatory Guide 8.22, the acceptable methods for the quantification of uranium in urine must have a detection limit of 5 pg/mL and a precision of 30% (Kressin 1984). A urinary concentration >100 pg/L is indicative of recent absorption, while a concentration of <40 pg/L may be due either to slow uptake from the site of absorption or to bone mobilization (Butterworth 1955). Variations in background levels of uranium from drinking water in different locations may also result in higher or lower urinary concentrations of uranium. 

Applicable regulatory guides for applying RIPBR to digital I C QA program. 

First we will review the RIPBR in general, then we will discuss Regulatory Guide 1.176 in more details because it is the most relevant guidance to digital I C QA activities. 

Based on the country of origin concept, in performing the software V V for the Limgmen project, the USNRC Standard Review Plan (SRP) Chapter 7, BTP-14 and USNRC Regulatory Guide 1.168 are followed. Two teams-the GE independent verification and validation team (GE IWT) and the owner (the TPC) IWT (OrWT), are organized by GE and TPC respectively to carry out the IV V tasks. 

Regulatory Guide 1.168, Verification, Validation and Audits for Digital Computer Software Used in Safety Systems of Nuclear Power Plants, Sept. 1997... 

The safety case documentation providing evidence that the applicable requirements of the design for safety have been met in the design and implementation of the refurbished I C systems important to safety will have the format and contents as per the US NRC Regulatory Guide 1.70 and Chapter 7 of the US NRC Standard Review Plan (year 1997 issue). 

The format of the PSID generally follows the outline previously documented and agreed to by the NRG. (Refs. 7 and 8) Except for the key modifications noted below, the format is generally consistent with that identified in Regulatory Guide 1.70. 

Another modification to the guidance provided by Regulatory Guide 1.70 is the clear distinction given to structures, systems and components within the Nuclear Island as opposed to those in the Energy Conversion Area (see Section 1.6). The discussion of the latter systems, which have no radionuclide control functions, is limited to a functional description and an identification of interfaces with the Nuclear Island. 

The meteorological factors used for the design of the Standard MHTGR in terms of accidental releases of activity are based on the guidelines found in Regulatory Guide 1.4. 

Consistent with Regulatory Guide 1 4, the 0 to 8 hr release dispersion factor includes a Building Wake Correction factor of 2.1 based upon a maximum building cross-sectional area of 748 m. ... 

The damping values used are those provided in Regulatory Guide 1.61, Damping Values for Seismic Design of Nuclear Power Plants, except as described below. (Ref. 3)... 

The steam generator Isolation valves and primary coolant pressure relief valves must perform their mechanical motion during and after a seismic event. A qualification program consistent with Regulatory Guide 1.148 and comprising qualification tests and/or analyses of these valves assures operability during and after a seismic event. 

The seismic instrumentation program (see Section 7.4.3) is consistent with the Regulatory Guide 1.12, Rev. 1, except for the items listed below (Ref. 13)... 

Response spectrum recorders are not supplied as discrete instruments. A permanently installed response spectrum analyzer provides more complete information than that provided by response spectrum recorders. Data from the strong motion accelerometers are fed into the response spectrum analyzer to produce earthquake spectra immediately following an earthquake. The response spectrtun analyzer is located in the Reactor Service Building with readout both there and in the Control Room. This system achieves the intent of Regulatory Guide 1.12, Revision 1. (Ref. 13)... 

Building similar to those required by Regulatory Guide 1.12 at the base and operating floor of the containment building of an LWR. (Ref. 13) The first two Reactor Buildings on a site will be... 

The remainder of the seismic sensing instrumentation is located on a basis consistent with the intent of the regulatory position of Regulatory Guide 1.12 which acknowledges the basic differences in characteristics between the MHTGR and LWRs. 

An assessment of the structural adequacy of the Reactor Building was performed. The structural code used was ACl 349 modified in accordance with Section 3.8 of the PSID to be consistent with Regulatory Guide 1.142. (Ref. 14) The loads considered were ... 

U.S. Nuclear Regulatory Commission. Design Response Spectra for Seismic Design of Nuclear Power Plants. Regulatory Guide 1.60, Revision 1. Washington, DC, December 1973. 

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