ML20207E511
| ML20207E511 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 07/14/1986 |
| From: | Gutterman A HOUSTON LIGHTING & POWER CO., NEWMAN & HOLTZINGER |
| To: | Bechhoefer C, John Lamb, Shon F Atomic Safety and Licensing Board Panel |
| References | |
| CON-#386-028, CON-#386-28 OL, NUDOCS 8607220359 | |
| Download: ML20207E511 (50) | |
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NEWMAN & HOLTZINGER, P.C. 00CXETED 1683 L STREET. N.W.
JACK R NEWMAN WASHINGTON. D.C. 2O036 . wiLuAM E. BACR. JR.
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MAURICE AXELMAD 202 955 6600 --
JANET E e ECmER J A BOURN'GMT JR MERLE W FALLON PAUL M RECK . STEVEN P FRANT2 GEORGE L. EDGAR
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JILLE GRANT DOUGL AS G GREEN KAROL LYN NEWMAN N$I! AUSON LeMASTER MOLLY N UNDEMAN JOMN T. STOUGM. JR MEVIN J UPSON JAMES 5 VA& ALE DAVID B RASKIN MeCMAEL A. BAUSER ALYIN M GUTTERMAN W ,. y JANEtRvAN
' = = - DONALD J. SILVERMAN KEVIN P. GALLEN JACOLYN A. SIMMONS u wAgt ,H y a..~ .J 4 -v u ' ~-
ROSCRT t. WHITE SCOTT A. MARMAN ROSENT LOWENSTEIN NORMAN A. FLANINGAM or Cousette July 14, 1986 Charles Bechhoefer, Esq.
Chairman, AdministrrJ.ive Judge Atomic Safety and Licensing Board Panel U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Dr. James C. Lamb, III Administrative Judge 313 Woodhaven Road Chapel Hill, North Carolina 27514 Frederick J. Shon Administrative Judge U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Re: Houston Lighting & Power Co., et al.
South Texas Project, Units 1 & 2 Docket Nos. 50-498 OL, 50-499 OL l
Dear Members of the Board:
In response to the Licensing Board's Memorandum and Order (Board Questions Concerning Design of Nonconforming Structures to Withstand Hurricanes and Tornadoes) dated June 23, 1986 (Memorandum and Order) Applicants herewith submit the Applicants' Answers to the Board's questions. Applicants' Answers respond to the questions posed in the Memorandum and Order and thereby provide additional explanation of the Applicants' analyses
! of the probability of a tornado or hurricane missile striking the
" nonconforming structures."
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- DR amen e as""
3 503
NawxAN & HoLTztwoma, P. C.
(e-f Charles Bachhonfer, Esq.
Dr. James C. Lamb, III Frederick J. Shon July : , 1986 Page 2 In its Partial Initial Decision (Operating License)
(Phases II/III) dated June 13, 1986 (PID), the Licensing Board questioned whether the potential missiles considered in Applicants' probability analyses were limited to those in the spectra in Standard Review Plan (SRP) Section 3.5.1.41/ Slip Op.
-1/ The Board also indicated that it could not accept "in its entirety" the position of the Staff that the number of locations where missile barriers are not provided is not a
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critical factor as 1ong as the overall probability of l missiles striking these locations meets the Staff's t acceptance criteria. Slip Op. at 81. The Board's statement is based upon its reading of a portion of the commission's preliminary policy statement on " Safety Goal Development Program," 48 Fed. Reg. 10772 (March 14, 1983). Id. at 81-82.
However, notwithstar.cing this theoretical difference between .
the Board and the Staff, the Board determined that the STP design would be acceptable "if the probabilities were adequately determined." Id. at 82-83.
Since the question left open by the Board is simply a factual one -- i.e., whether Applicants have adequately demonstrated that the Staff's acceptance criterion has been satisfied in this case -- Applicants have not and do not ask the Board to reconsider its interpretation of the Commission's 1983 policy statement. However, we should point out that we believe that the Staff's position -- which we understand to be the same as Applicants' position -- was fully consistent with the 1983 policy statement. Simply put, our position was that as long as the cumulative probability of an event (e.g., the striking of " nonconforming structures" by hurricane or tornado missiles, regardless of the number of l " nonconforming" locations) was sufficiently remote that it l did not exceed the Staff's acceptance criterion of 1 x 10 7 ,
there was no need to analyze the further probability of l damage or significant releases of radiation (which would be even lower) and the facility was deemed to satisfy NRC l requirements without the addition of physical protection I against such a low-probability event. Prior to 1983, the staff's use of the screening criterion to judge the l
credibility of postulated events was recognized and accepted by the Commission. E.g., Offshore Power Systems (Manufacturing License for Floating Nuclear Power Plants);
LBP-82-49; 15 NRC 1658, 1722 (1982); Portland General l Electric Co. (Trojan Nuclear Plant), LBP-78-32, 8 NRC 413,
! 429-33 (1978), af f 'd, ALAB-531, 9 NRC 263, 277 (1979); see
! also Florida Power & Light Co. (St. Lucie Nuclear Power l
l (footnote continued) l l
NWMAN & HorrzzNaza, P. C. ;
\.
f Charles Bachhonfer, Esq.
Dr. James C. Lamb, III Frederick J. Shon July 14, 1986 Page 3 i
at 84. Applicants' Answers show that Applicants' STP probability analyses utilized an Electric Power Research Institute (EPRI) report of the results of on-site surveys of nuclear plant sites to determine a range of densities of potential missiles. The EPRI survey did include in its count missiles of lower severity than the missiles in the SRP Section 3.5.1.4 spectra. Answer 4.
Moreover, to account for local variations in missile densities and plant to plant differences, the missile density upper limit for i
the EPRI cases utilized in the STP analyses (as normalized to two operating units) was increased by a factor of 2.5. Id. In addition to summarizing the methodology and assumptions used in the STP probability calculations, Applicants' Answers also identify a variety of conservative assumptions which give confidence that the STP analyses in fact overestimated the probability that a missile within the EPRI spectrum would strike any of the " nonconforming structures" or " unprotected equipment."
Answers 5 and 8. Although missiles less severe than those in the
! EPRI spectrum (identified as " debris" in Answer 7) were not included in the STP analyses, Applicants' Answers show that such omission was appropriate because the potential for damage from debris is considered to be negligible, and that other conservative 1 (footnote continued from previous page)
Plant, Unit No. 2), CLI-81-12, 13 NRC 838, 843-44 (1981). We see nothing in the 1983 policy statement -- which, to us, seems to be addressed to overall safety goals for a nuclear plant as a whole -- that would cast any doubt on the continuing validity of the Staff's use of the screening criterion for particular events or that would limit the number of locations that could be affected by an event subjected to the screening criterion. In adopting the 1983 statement, the Commission emphasized that existing NRC requirements were not being altered or replaced (48 Fed. Reg. 10772, 10775), and, since such adoption, use of the Staff's acceptance criterion has continued. E.g., Cleveland Electric Illuminating Co. (Perry Nuclear Power Plant, Units 1 & 2),
LBP-83-46, 18 NRC 218 (1983); see also Metropolitan Edison Co. (Three Mile Island Nuclear Station; Unit 1), CLI-84-11, 20 NRC 1, 9-10 (1984). Recently, the Commission approved a final policy statement on safety goals, superceding its 1983 statement. See " Discussion Version" of " Policy Statement on Safety Goals for the Operation of Nuclear Power Plants" (June 18, 1986), as modified and approved at the Commission meeting of June 19, 1986. Similarly, Applicants find nothing in such statement that casts any doubt on the continuing validity of the Staff's use of the screening criterion for particular events.
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NzWMAN & HOLT 21NOE2, E C.
Charlos Bochhoofer, Esq. I Dr. James C. Lamb, III Frederick J. Shon July 14, 1986 Page 4 assumptions in the analyses provide such a wide margin that any I reasonable increase in the assumed missile population would not I alter the conclusion that the probability of a 7 missile striking a
" nonconforming structure" is less than 1 x 10 (Answers 6 and 8).
The Memorandum and Order also includes questions about the potential for damage to safety-related equipment from missiles (whether or not included in the spectrum considered in Applicants' analyses) and the risk of release of radiation due to a missile striking such equipment. The Applicants' Answers show that the safety-related components in the Isolation Valve Cubicle (IVC) are primarily thick walled steel components which would not be damaged by missiles less severe than those considered in the probability analyses (Answer 7), and that even if such components or other
" unprotected equipment" were damaged by any hurricane or tornado missile there would be little risk of significant release of radiation (Answers 7 and 11). Any missile strike to a diesel generator exhaust stack would not affect diesel operation unless it blocked approximately 40 percent or more of the exhaust flow, and even if one diesel failed to function there would be little risk of significant release of radiation. Answers 7 and 11.
Finally, were any missile to strike any of the MEAB HVAC openings the consequence would simply be to create the possibility that certain portions of the MEAB would be depressurized, but there would be little risk of a significant release of radiation.
Answers 7 and 11.
Thus, Applicants' Answers show that the STP probability analyses adequately support the conclusion of the NRC Staff that the risk of a tornado or hurricane missile syriking the "unpro-tected structures" is much less than 1 x 10 per year, that the risk of release of radiation in excess of Part 100 limits due to i such an event is even smaller and that the plant design is "in conformance with GDC 2 and 4 with respect to missile protection."
SER section 3.5.2. On the basis of this information the Board should grant summary disposition on the limited aspects of Contention 4 left unresolved by the PID.
i
NawwAx & HOLTZINOEn, P. C.
Charles Bechhoefer, Esq.
Dr. James C. Lamb, III
, Frederick J. Shon July 14, 1986 Page 5 i
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- In the PID the Board also reiterated that CCANP was given until June 9, 1986 to raise questions regarding whether STP has been adequately constructed to withstand hurricanes. No filing from CCANP has been received. Accordingly CCANP's conten-4 tion about the adequacy of the construction should also be l dismissed.
Respectfully submitted, h
Alvin H. Gutterman Attorney for Applicants j Enclosure j cc (w/ encl.): Service List f
t
UNITED STATES OF AMERICA o NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD I
I In the Matter of ) !
)
HOUSTON LIGHTING & POWER ) Docket Nos. 50-498 OL COMPANY, ET AL. ) 50-499 OL
)
(South Texas Project, ) {
Units 1 and 2) )
Applicants' Answers to the Board Questions Concerning Design of Nonconforming Structures to Withstand Hurricanes and Tornados QUESTION 1:
Define the particular MEAB HVAC openings which have been identi-fled as not designed to withstand tornado- or hurricane-generated missiles.
ANSWER 1: (DEA)
The MEAB HVAC openings which have been designed to withstand tornado or hurricane-generated missiles are described briefly below. Additional design details relevant to their safety
, significance and potential resistance to missiles are provided in i
Answer 7. For each of the two STP units:
A. An outside air intake is located on the east side of the MEAB extending between elevation 60' 3" and elevation 72' 3" (grade is at elevation 28'). The intake is subdivided to form three openings of 21', 22' and 13.5' in length (252, 264 and 162 square feet in
area, respectively) separated by two-foot wide concrete columns. The intake openings are covered on their outside face by fixed position aluminum louvers and on their inside face by tornado dampers, slightly smaller than the openings, as described in more detail in Answer 3. Egg FSAR Figure 1.2-29 (sheet 3 of 4).
B. The exhaust fan opening for elevator shaft #5 is a 2.25' x 2.25' opening in the roof at elevation 90'. An j
exhaust fan is mounted on the outside face and a 2.25' x 2.25' tornado damper on the inside face. Egg FSAR-
. Figure 1.2-30 (sheet 4 of 4).
1 C. The exhaust and intake openings into elevator machine room #4 are 2.5' x 2.5' and 2.25' x 2.25', respec-i tively, in the roof at elevation 99'4". An exhaust fan I
is mounted on the outside of the exhaust opening and there is an inverted "J" shaped duct over the intake.
l On the inside face of each opening are 4' x 4' tornado l
l dampers. Egg FSAR Figure 1.2-30 (sheet 2 of 4).
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{ D. The HVAC supply and return ducts for the Technical Support Center (TSC) are run through two separate 3.5' x 2' openings in the roof (elevation 86'), which also serves as the floor for the TSC HVAC Equipment Room.
There are 3.5' x 2' tornado dampers on the inside face of each opening. (The TSC HVAC Equipment Room, which provides weather protection for certain TSC HVAC
)
equipment, is not safety-related; it is a roof top l
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l structure that is designed to withstand hurricane winds but is not designed to withstand tornado winds or
- missiles.) In addition, the TSC Toilet Exhaust Fan, also located in the TSC Equipment Room, has a 16" x 16"
- opening in the MEAB roof at elevation 86'. There is an exhaust fan on the outside face and a 12" x 12" tornado damper.on the inside face. Egg FSAR Figure 1.2-30 4
(sheet 2 of 4).
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- QUESTION 2:
Define the particular diesel generator exhaust stack openings which have been identified as not designed to withstand tornado-or hurricane-generated missiles.
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l ANSWER 2: (DEA)
. For each of the two STP units, there are three diesel generator exhaust stack openings - each of which serves one of the three STP standby diesel generators - located on the north face of the diesel generator building (DGB) at elevation 95'8". The three j 48" diameter circular openings are located 35' from each other 1
(center to center). The exhaust stacks are fabricated from 32" diameter 3/8" thick chromium' molybdenum alloy pipe and each extends horizontally 3" beyond the wall surface. A hood above the exhaust stack to provide weather protection is designed to allow sufficient exhaust flow even if impacted by a missile.
QUESTION 3:
Define the protected equipment which each nonconforming structure
, would normally protect.
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ANSWER 3: (DHA)
The " protected equipment," 12g. the equipment or components which would be protected from tornado and hurricane missiles if a missile barrier were constructed over the respective opening, is as follows:
A. MEAB HVAC Openinas The MEAB HVAC openings have tornado dampers on the interior face of each opening. The tornado dampers, which are multi-section, multi-blade galvani=ed steel (similar in appearance to a venetian blind), are designed to close in the event of outward flow caused by the depressurization effects of a tornado. The purpose of these dampers is to prevent tornado depres-surization within the MEAB. These tornado dampers are the only safety-related equipment which could be struuk i by a missile entering these openings. All other safety-related equipment in the vicinity of these openings is protected by internal concrete walls and floors or barriers which will withstand the design basis tornado missiles. Egg FSAR Figures 1.2-29 (sheet 3 of 4) and 1.2-30 (sheets 2 and 4 of 4).
B. Diesel Generator Exhaust The only safety-related equipment which could be damaged by a missile striking a DGB exhaust stack opening is the DGB exhaust st'ack. Other safety-related equipment in the DGB, including the diesel generator,
is protected by internal concrete walls, floors or
- missile barriers which will withstand the design basis tornado missiles. Egg FSAR Figure 1.2-10, Section "A-A".
C. Isolation Valve Cubicle (IVC)
The IVC for each of the two STP units is divided into four compartments, separated from each other by reinforced concrete walls that are capable of withstanding the design basis tornado missiles. Egg FSAR Figure 1.2-25. Each of the four compartments contains equipment associated with an individual steam generator. The following safety-related equipment in each compartment could be impacted by a missile: the main steam and feedwater piping, the main steam and feedwater isolation and bypass valves, the Steam 1
l Generator Power Operated Relief Valve (PORV), the Safety Relief Valves (SRV) and the auxiliary /feedwater cross-connect piping and isolation valves (including i the power supply cables and controls associated with the various valves). In addition the IVC HVAC fans, which provide cooling to the IVC and the AFW pump rooms, are located on the roof of the IVC adjacent to the Reactor Containment Building.
i i
QUESTION 4:
For each of the nonconforming structures, what are the externally generated missiles (or the spectrum of missiles) used by the Applicants or Staff to determine the probability of a tornado- or hurricane-missile strike?
ANSWER 4: (AJM, DHA)
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The assumed missile spectrum used in the probability analysis for each of the " nonconforming structures" was the same. It was based on a survey of potential tornado missiles at nuclear plant sites reported in a study sponsored by the Electric Power Research Institute (EPRI). 1/ In the survey, potential tornado
, missiles were identified, characterized and counted at seven l nuclear plant sites in various stages of construction and operation. The objects counted as potential missiles included not only construction materials and objects found about the plant sites, but also missiles which could originate from failures of structures not designed to withstand tornados. Such structures not designed for tornado loads included both temporary con-struction buildings and permanent facilities. The potential missiles were grouped into 26 categories, depending on their material and shape.
The EPRI survey included in its count those potential missiles which appeared to pose a threat to plant safety. The EPRI spectrum of missiles was broader than the spectrum included in 1/ Twisdale, L.A., gi gl., Tornado Missile Risk Analysis, Electric Power Research Institute report, EPRI NP-768 (main l report) and EPRI NP-769 (appendices), May 1978.
_,-,-..----,,,,,-a.,.- - _ . - . . -. ,, - .,.._,,,.-_.-e., - . - , . - - - - - - , , - - . - - . . - - - . - - - , - . _ - _ . - - , - , . , - ~ - , -
Standard Review Plan (SRP) Section 3.5.1.4. The EPRI spectrum of missiles ranged from such large objects as autos, trailers, and l 36 inch diameter steel pipe (6 ft. long) to relatively small objects such as steel rod one inch in diameter (8 ft. long),
steel pipe 2 inches in diameter (4 1/2 ft. long) and pieces of wood 2 inches wide by 1/2 inch thick (12 ft. long).
The STP probability analysis based its assumptions about missile density on the EPRI survey results for a three-unit plant with all units in operation and a one unit operating plant. 2/ The survey for these two plants showed a range in values (normalized to two units) of between 5,836 and 6,196 missiles. To account for local variations in missile densities and plant to plant differences, the STP analysis assumed that the median number of potential missiles would be 6,000 but that the actual number could be slightly more than 15,000 (121., an increase by a factor of approximately 2.5). As discussed further in Answer 5, the parameters of the missiles reported in the EPRI study were used 2/ The other plants surveyed by EPRI had one or more units under construction and had many construction materials which would not be present on the STP site during plant operation.
Any difference in missile density due to continued construction at Unit 2 is considered to be insignificant in terms of the overall risk. Since Unit 2 is anticipated to load fuel approximately 18 months after Unit 1, construction related missiles are expected to be on site for only a limited time. In addition it should be noted that for approximately six months of this time Unit I will be undergoing low power testing. During the remainder of this time, Unit 2 will be undergoing startup testing (not major construction).
to chigacterize an average or " standard" missile which would be
!- representative of the aerodynamic properties of the entire missile population. ;
l 1
QUESTION 5: l l
For these nonconforming structures, how were the above-specified missiles factored into the probability figures set forth by the Applicants and Staff, respectively? Provide details as to particular types of missiles, velocities assumed, definition of and probabilities for storms utilized and the rationale for any limits applicable to any facets of the probability calculations.
ANSWER 5: (AJM)
The following summarizes the methodology and assumptions used in the STP probability calculations. Additional detail is provided in the reports submitted to the NRC Staff 3/ and summarized in Attachments II, III, and IV to the affidavit of R. Bruce Linderman dated March 11, 1985.
l The STP tornado- and hurricane-missile probability analyses l modelled the probability of a missile striking unprotected targets at the STP site as the product of two terms: (1) the annual probability of occurrence of a hurricane or tornado at the STP site and (2) the conditional probability of a potential missile striking a target, given the hurricane or tornado occurrence. The annual probabilities of tornados and hurricanes of different intensities striking the STP site were determined 3/ Letters to Mr. Thomas M. Novak (U.S. NRC) from J. H.
Goldberg (HL&P) dated September 13, 1983 (ST-HL-AE-1003),
November 14, 1983 (ST-HL-AE-1028), and December 20, 1983
- (ST-HL-AE-1040).
l l
1
using historical data. The conditional probability of a potential missile striking a target at the STP site was determined using a statistical mechanics model. The important parameters of this model include the surface density of near-ground and elevated missile sources; the missile aerodynamic properties; the three dimensional orientation of the missiles relative to the windfield; the aerodynamic and restraining forces that tend to promote or retard the escape of the missiles from the injection zone; the characteristics of the windfield that govern the subsequent flight of the missile from the injection zone to the point of impact; and target size and elevation.
The missile densities and missile aerodynamic properties utilized are representative of the missile spectrum identified in the EPRI study described in Answer 4. The missile densities were derived from the area of the missile origination zone (approxi-mately one square mile) used by EPRI and the expanded range of missile numbers described in Answer 4. The aerodynamic parameters of a typical (" standard") missile were derived such that the median probability of hitting a unit area of target by a standard missile was the san.e as the sum of the unit area strike l
probabilities for the individual missile types and densities reported in the EPRI study. The standard missile aerodynamic parameters were then used as the basis for all subsequent calculations.
l
Since the aerodynamic parameters of the standard missile reflect the missile spectrum identified in the EPRI survey, a change in the parameters wculd occur if a different missile spectrum (e.o., with more light missiles) were postulated. However, because of the conservatisms which will be subsequently explained, the STP probability analysis results are not significantly affected by the numerical values assigned to the aerodynamic parameters of the standard missile. As discussed below, because of certain conservative assumptions used in the analysis, a large increase in the postulated percentage of light missiles in the missile spectrum could occur without signifi-cantly altering the probability of a tornado- or hurricane-generated missile striking any of the unprotected targets at the STP site.
One half of the potential missiles are assumed to be uniformly distributed up to 20 feet above grade, with the remainder at grade. The EPRI study concluded that the number of elevated objects is significantly smaller than the near-ground missile sources, although the elevated missile sources constitute the greater relative threat per object because of their potential energy of position and favorable location relative to windspeed strength. Thus, assumption of 50 percent elevated missiles in the STP analysis is conservative.
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_ -,.,s_7- -
Ten percent of the missiles were assumed to be unrestrained, such that they can be dislodged easily during even low intensity tornado and hurricane winds. This assumption results in a conservative estimate of the total probability of a missile striking the target.
Injection of a potential missile during a tornado or hurricane requires that the restraining forces be overcome by the aero-dynamic forces. The restraining forces 8.nclude gravitational, frictionta structural, and interlocking forces. Missile injection is modelled as a function of seven parameters:
windspeed, the angle of " attack" (itg., the angle between the wind direction and the missile pitch); the three Euler angles that characterize the orientation of the drag forces and lift forces within a spherical system of coordinates; the lift restraint coefficient and the drag restraint coefficient. The latter are functions of the aerodynamic parameters (drag coefficient and lift coefficient) of the standard missile. The missile injection model treats the seven injection parameters as random variables with uniform distributions over their allowable ranges. The range of windspeeds used in the model for the tornado missile analysis is taken as the lower and upper levels of windspeed corresponding to each of the seven levels in the Fujita scale of tornado intensity (total range of 40 to 380 mph.)
The windspeeds used in the hurricane missile analysis ranged from
75 to 247 mph. The resulting fitted distribution for windspeeds implicitly considers the probability of missile injection at lower windspeeds. However, the probabilities are very small.
Using Monte Carlo simulation, the probability of horizontal injection,. vertical injection and total injection are computed as
, functions of the tornado or hurricane windspeed. Between one and two orders of magnitude of conservatism are incorporated into the injection probabilities through use of the following assumptions:
(1) The angle distribution of all potential missiles
! 1 is random except as noted in (2) below. The EPRI report stated that approximately 70 percent of the missiles observed in the survey were oriented horizontally, which is unfavorable for injection.
Thus the acsumption of a random distribution increases the probability of successful missile injections.
(2) The maximum cross-sectional area of each missile is oriented perpendicular to the wind, which maximizes the probability of potential missiles becoming airborne.
Because of these assumptions, the probability of successful injection is enhanced, which effectively makes the missiles behave during the injection phase as if they were " lighter" than j
they actually are. Although lighter missiles would, on the l
l average, be transported further than the representative standard
missiles, the difference would not significantly affect the
~
result. Trajectory simulation studies in the EPRI report demonstrated that the maximum range of some heavier missiles exceed those for light missiles. This is because the lighter missiles typically follow a more spiral trajectory, which results in impact points closer to the injection point. Overall, however, the mean ranges of both light and heavy missiles are less than 350 feet, and pose a small chance of traveling more than 1000 feet from their point of origin.
In the STP analysis, a Green's function is used to determine the probability of a missile being transported from its point of origin to the target (a defined elevation and surface area). The missile velocity is a random variable embedded in the expression of the average Green's function. It could be " backed out" of the Green's function by an additional calculation. Because the STP analysis calculated only the probability that a missile would strike the target (12g., the IVC roof, DGB exhaust or MEAB HVAC openings) and not whether it would cause damage, the resulting energy and velocity of the missile at impact were not separately calculated.
Hurricane occurrence and intensity data which were utilized in
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the probability calculations are based on an NRC-sponsored study. 4/ A Weibull distribution was used to compute hurricane high wind distributions for the STP site based on historical data for Corpus Christi and Galveston. A sensitivity study was performed to quantitatively evaluate the potential sources of error that could affect the fitted Weibull distribution parameters. The selected parameters were conservatively chosen to bound such potential errors.
Tornado occurrence frequency near the STP site was based on a 30 year historical record of tornado occurrences within Matagorda County and the five adjacent counties. Tornado occurrence frequency estimates obtained from this record are higher than estimates derived for a 10,000 square mile area centered at the STP site, and for the state of Texas normalized to a 10,000 square mile area. The joint distribution of the tornado path area and Fujita intensity are based on tornado occurrences within the state of Texas. Additional information about storm inten-sities and occurrence frequencies utilized in STP's analysis are presented in HL&P's September 13, 1983 and November 14, 1983 submittals to the NRC (cited in footnote 3, above).
1 4/ Changery, M.J., Historical Extreme Winds for the United States - Atlantic and Gulf of Mexico Coastline, NUREG/CR-2639, May 1982.
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QUESTION 6:
Are there externally generated missiles other than those listed in response to Question 4 that could conceivably strike any of the nonconforming structures or protected equipment during a tornado or hurricane? If so, specify what missiles, or range of missiles, could strike any or all of the nonconforming structures and/or protected equipment.
ANSWER 6: (AJM)
There are externally generated missiles other than those listed in Answer 4 that could conceivably strike the " nonconforming structures" or " protected equipment" during a tornado or hurricane. The missiles not included in the STP analysis are
, those smaller than the spectrum considered in the EPRI study, as described in Answer 4.
The omission of such small missiles (itg., debris) from the missile spectrum is considered appropriate because, as noted in Answer 7, the potential for damage from debris is considered to be negligible. In addition, other assumptions in the analysis are sufficiently conservative to provide such a wide margin that any reasonable adjustments in the missile characteristics or missile population would not alter the conclusion that the probability of a missile striking a " nonconforming structure" is
-7 ,
less than 1 x 10 l
\
Although lighter missiles would become airborne more readily, as
- noted in Answer 5, the methods used to model the injection of potential missiles has the effect of making all missiles behave as if.they were lighter than they actually are.
With regard to increases in the total number of potential missiles, no reasonable assumption about the number of missiles would alter the ultimate result. This conclusion is based on the fact that:
- 1. There is considerable margin between the calcu-lated probability of missile strike (approximately 6 x 10-10) and the NRC acceptance criterion for probability of release of radiation in excess of kf" Part 100 guidelines. EgJt SRP Section 3.5.1.4.
- 2. As discussed in Answer 5, there is considerable conservatism in the modeling techniques used in the study.
- 3. The missile density upper limit was increased by a factor of 2.5 over the EPRI survey to account for variations in local missile density.
Based on these factors, it is concluded that the number of potential missiles would have to be increased by several orders of magnitude before the strike probability approaches the acceptance criterion for radiation release.
QUESTION 7:
What damage, if any, might be foreseen to result to nonconforming structures or protected equipment if any of the missiles identified in response to Questions 4 and 6 were to strike any of the nonconforming structures or protected equipment? If differing degrees of damage are dependent upon the type of missile, please explain.
ANSWER 7: (DHA, RBL)
The effect of missiles impacting nonconforming structures or protected equipment can best be explained by consideration of three general types of missiles. These are:
- 1. Debris. Small, lightweight objects which were not specifically included in the probability analysis.
In general, as described in more detail below, these types of missiles do not have sufficient energy to cause damage of any significance to the safety-related equipment described in Answer 3.
- 2. Licht Missiles. Objects such as pieces of wood, sheet metal, plywood, tree limbs, etc. As noted in Answer 4, these items have been considered in the probability analysis.
- 3. Substantive Missiles. Missiles of moderate to heavy weight, such as large pieces of lumber, pipes, etc. As noted in Answer 4, these items also have been considered in the probability analysis.
l 1
)
The potential for damage from the impact of each missile type for each of the " nonconforming structures" is addressed below without consideration of the probability of occurrence.
A. As mentioned in Answer 3, the IVC is divided into four compartments by full height reinforced concrete walls which are capable of withstanding the design basis tornado missiles. Each compartment contains the equipment listed in Answer 3 associated with one of the four steam generators.
Although the STP probability analyses made the conservative assumption that there is no roof on the IVC, in reality each of the four IVC compartments has a roof made of 18 gauge steel with a small pertion constructed of reinforced concrete. The steel portions of the roof will withstand hurricane winds, but could be removed by a tornado. If the roof is not removed by tornado winds or significantly damaged by a substantive missile it will effectively protect the equipment l
within the IVC from debris and some light missiles.
Most of the safety-related equipment listed in Answer 3 is located below one or more levels of grating. Since the grating is designed to support personnel and equipment, it would withstand the impact of debris and most light missiles.
The main steam and feedwater piping are heavy steel pipe which would withstand the impact of debris and light missiles. The main steam and feedwater isolation and bypass valves and the PORVs and SRVs have heavy steel valve bodies which would withstand the impact of debris and light missiles. The auxiliary feedwater cross-connect piping and isolation valves are also heavy steel components that would withstand the impact of debris and light missiles. Thus, the only safety-related equipment in the IVC which could be affected by debris or light missiles are the fans and the power supply cables and valve control systems associated with the main steam and feedwater isolation and bypass valves and the PORV. Failure of power supply cables or control to any of the valves will result in that valve failing closed (safe position). Failure of the IVC HVAC fans would not affect the ability to safely shut down the plant.
Even if substantive missiles are assumed to be capable of causine damage to any of the safety-related equipment listed in Answer 3, as discussed further in Answer 11, there is very little risk that such damage would result in a significant release of radiation.
Such accidents and transients in any one cubicle are l
l 1
I i
i included in the STP design basis and analysis of these
~
events are included in the STP FSAR. Egg FSAR, Sections 15.1 and 15.2.
B. MEAB HVAC Openinas As described in Answer 3, the only safety-related equipment which could be affected by a missile striking any of the MEAB HVAC openings is the tornado dampers.
The dampers are located on the inside face of the openings. 5/ The tornado damper blades are made of 10 gauge steel (1/8" thick) and would therefore be of sufficient strength to withstand debris.
The extent to which a tornado would depressurize the
, interior of the MEAB through an opening in a tornado damper would be dependent on the size of the opening.
Failure of only a small section would not significantly reduce the effectiveness of the large dampers.
- Therefore debris and light missiles would not significantly reduce the effectiveness of the large dampers.
i I
l 5/ There are fixed position aluminum louvers on the outside face of the intake openings on the east side of the MEAB.
l The smaller MEAB HVAC openings described in Answer 1 all have coverings on their outside face, such as HVAC duct or fan housings. Such louvers and coverings are generally not designed to withstand tornados or hurricanes.
Even if the tornado dampers were to fail completely, no adverse effects would be expected. An evaluation of the internal walls in the vicinity of the various openings has shown that they would maintain their structural integrity in the event of full depressurization (3 psi). Egg ST-HL-AE-1574 (January 10, 1986) regarding analysis results for the limiting cases. No anticipated effects of depressurization on safety-related equipment in the adjoining rooms would adversely affect the ability to safely shut down the plant.
C. Diesel Generator Exhaust Stacks B
As discussed in Answer 3, the only protected equipment which could be affected by a missile strike in an exhaust stack opening is the stack itself. Other safety-related equipment in the DGB is protected from external missiles by reinforced concrete walls, floors or other missile barriers which will withstand the design basis tornado missiles.
A missile strike in an exhaust stack would only interfere with diesel operation if it resulted in blockage of approximately 40 percent or more of the 32" l
diameter exhaust stack opening. Even in that
! circumstance, only the diesel associated with that specific exhaust stack would be affected.
l l
l l
The diesels are only required to function in the event
- of loss of offsite power. In that event only one of the three diesels would be required to safely shut down the plant. Egg FSAR, Fire Hazards Analysis Report, Section 2.4.1.4. In addition it should be noted that STP will meet the NRC's proposed Station Blackout rule (51 Fed. Reg. 9829 (March 21, 1986)),
which would require that there be no adverse safety consequences following a loss of offsite power and simultaneous loss of all three diesels for a period of four hours.
QUESTION 8:
State the combined probability of any of the missiles identified in response to Questions 4 and 6 striking each of the noncon-forming structures or the equipment protected by each in the event of a hurricane and/or tornado.
ANSWER 8: (AJM, DHA, RBL)
The probability of any of the potential tornado or hurricane missiles identified in Answer 4 striking any of the "noncon-forming structures" (or the " protected equipment") is conser-vatively bounded by the results which have been previously l reported. As explained in the Affidavit of R Bruce Linderman dated February 17, 1986, this combined probability is
-10 approximately 6 x 10 per year.
If debris (as defined in Answer 7) were added to the numbers of 1
potential missiles considered in the STP analysis, the computed strike probabilities would increase in approximate proportion to the increase in the assumed density of missiles (given that the j same conservative modelling assumptions were employed). However, the calculated results for missile strike probability are several orders of magnitude smaller than the NRC acceptance criterion for P.he probability,of release of radiation in excess of Part 100 Guidelines. Thus, even if missile densities are assumed to be much greater than indicated by the EPRI survey data, the NRC acceptance criterion would still be met. Moreover, as noted in Answer 7, most debris would lack sufficient energy to adversely affect the safety-related equipment described in Answer 3. Thus, although the target strike probabilities would be higher had debris been considered, the damage probability would not significantly change.
l
) The significant sources of conservatism, as noted in the attachments to the submittals cited in footnote 3 (Answer 5, above) include:
- 1. Sheltering by other structures is neglected and the missile density is uniformly distributed regardless of the location of adjacent structures.
In reality there is significant sheltering from
the walls of the IVC, MEAB, DGB, and the Reactor ,
Containment Building, which is adjacent to the IVC and approximately 150 feet taller.
- 2. The missile density upper limit was increased by a factor of 2.5 over the EPRI survey to account for local variations in missile density.
- 3. The maximum cross-sectional areas of potential missiles are assumed to be perpendicular to the wind. This maximizes the probability of potential missiles becoming airborne.
It should also be noted that Applicants' calculations determined the probability of a missile striking any portion of the i
" nonconforming structures" (target area); they did not consider whether the missile impact would damage safety-related equipment; or whether such damage would result in a significant release of radiation. A significant portion of the missile strikes would not cause damage because some missiles would be of low energy, or much of the energy would be absorbed in missile deformation or by striking non-safety-related components or safety-related components capable of withstanding the impact, etc. Moreover, as discussed in Answers 7 and 11, even if there were damage to
" protected equipment" it would be unlikely to result in a significant release of radiation.
QUESTION 9:
In his affidavit dated March 11, 1986, Mr. R. Bruce Linderman states that Category I structures (with a specified exception) have been designed to withstand a spectrum of missiles that is
)
said to envelope missiles which could be generated from non-Category I structures (Linderman Aff., 1 22). Are any or all of such missiles included in the category of missiles set forth in response to either Question 4 or 6 above? Have any or all been included in calculating the probabilities of missile strike set forth by the Applicants or Staff, respectively?
- a. If either answer is affirmative, please explain the mechanism by which such missiles were included (itg.,
the particular missiles, the velocities assumed, and the manner in which probabilities were determined).
- b. If either answer is negative, please explain.
ANSWER 9: (AJM)
As discussed in Answer 4, missiles which could result from the failure of temporary and permanent structures not designed to withstand tornado winds were considered in the EPRI survey.
Therefore, they are included in the missile densities as described in Answer 5.
QUESTION 10:
State whether any or all of the nonconforming structures or protected equipment have been designed to withstand any of the missiles identified in response to Questions 4, 6 and 9. Please provide explanations as to how, and the degree to which, the nonconforming structures or protected equipment are protected against missiles, if that be the case. For structures which provide no effective protection against missiles (gig., the open IVC roof area), explain what additional protection, if any, is currently proposed to protect safety related equipment or j components located within the nonconforming structures. Please provide details concerning any such protection.
i I
l
- ANSWER 10
- (DHA, RBL)
The " nonconforming structures" and " protected equipment" will withstand many of the missiles identified in Answers 4, 6 and 9, although the ability to withstand such missiles results from various design considerations other than external missile protection, i
4 Answer 7 explains how, and the degree to which, these structures d
and equipment will withstand such missiles, including existing design features.
QUESTION 11:
Assuming a strike of an external missile on any of the noncon-forming structures or protected equipment, what is the pro-bability of a release of radiation in excess of the limits in 10 C.F.R. Part 1007 Provide answers for each nonconforming structure, item of protected equipment and, as applicable, for
- different types of missiles.
ANSWER 11: (DHA, RBL)
The probability of a release in excess of 10 CFR Part 100 limits has not been calculated for STP (whether or not a strike of an
- external missile on a " nonconforming structure" is assumed).
l Such a calculation would require an extensive probabilistic risk j assessment (PRA) which would involve substantial time and expense. Although a preliminary study of the risk associated
! with STP has been performed, it is not sufficiently thorough and specific to provide the requested probability values. However, it is believed that the risk of a release of radiation in excess t
l
of Part 100 limits would be extremely small, even assuming a missile were to strike a nonconforming structure. As discussed in Answer 7 and summarized below, the damage which might reasonably be postulated to result from a missile will not prevent the plant from being safely shut down or prevent successful mitigation of resulting transients and accidents.
These are bounded by FSAR analyses.
A. MEAB HVAC Openinos The only safety-related equipment which could be damaged by a missile strike on any of the
" nonconforming" MEAB HVAC openings is the tornado dampers. As discussed in Answer 7, damage to the tornado dampers and resulting depressurization is not expected to imp u/ the ability to safely shut down the plant. Therefon ene risk of a release of radiation in excess of Part 100 limits would not be affected by missiles striking the dampers.
B. DGB Exhaust Stack As discussed in Answer 7, a missile strike to a diesel i generator exhaust stack would not adversely affect diesel operation 6/ unless it blocked approximately 40%
I
! or more of the 32" diameter exhaust stack. Such a missile strike would prevent full power operation of l
6/ It would not affect any other safety-related equipment in any event.
one diesel generator and its associated IE distribution
- train, but would not initiate an accident or transient.
A single safety train (12g., one diesel) of the three STP safety trains will provide adequate power to safely shut down the plant in this event, even if coincident d
with a loss of offsite power. Sag FSAR, Fire Hazards Analysis Report, Section 2.4.1.4. Moreover, as mentioned in Answer 7, STP will meet the NRC's proposed Station Blackout rule. Therefore the risk of a release of radiation in excess of Part 100 limits, even assuming such a missile strike, would be small.
C. lyC As discussed in Answer 7, a missile strike to the IVC could affect equipment associated with only one of the four steam generators because the compartments are separated from each other by walls that will withstand the design basis tornado missiles. If a missile strike caused damage to the valve controls or power supplies, the result would be that a valve in one of the four compartments would fail to the closed (121., safe) position. STP has the capability to safely shut down the plant as long as the equipment in any one of the three other compartments is available. If a large substantive missile were to strike a pipe, there might be local deformation, with possible cracking of the
pipe. This condition is bounded by analyses presented in FSAR Sections 3.6.A.2, 15.1 and 15.2. Therefore the risk of a release of radiation in excess of Part 100 limits, assuming a missile strike on safety-related equipment in the IVC, would be small.
QUESTION 12:
What is the feasibility of providing missile protection, as required by General Design Criterion 4, for each of the noncon-forming structures or protected equipment? Explain which type (s) of protection (222., barriers conforming to the standards of SRP, S 3.5.3 (NUREG-0800)), if any, are feasible for each noncon-forming structure or item of protected equipment. Also specify which type is the least costly (or the type which, if required, would be preferred by the Applicants or Staff to be installed).
> Provide a full explanation why the chosen altenative would be preferable to others which may be available.
ANSWER 12: (RBL)
Although detailed design studies and analysis of potential design alternatives have not been performed, several design concepts for providing tornado missile barriers for the " nonconforming structures" have been reviewed. Based on these reviews, it appears feasible to design tornado missile barriers for each of these structures. 2/ In each case such barriers would most likely consist of reinforced concrete labyrinths.
i 1/ In view of the low probability of a missile striking the
" nonconforming structures" it was determined that tornado missile barriers would not be required. Consequently no detailed consideration has been given to alternative missile barrier designs.
l :
l l
A. lyg A reinforced concrete barrier could be constructed as an additional story to the IVC. This new roof would overhang three sides of the existing roof (like eaves) and be open at the bottom to provide the necessary vent area. (The fourth side faces the reactor containment building.) This vent area is required to relieve the pressures associated with postulated pipe breaks. 8/
Three other alternative missile protection concepts were considered, but each is believed to be less desirable than either the present design or the alternative discussed above. The advantages and disadvantages of each concept are discussed in Attachment 1 to Applicants' letter to Mr. Thomas M.
Novak of the NRC Staff from Mr. J. H. Goldberg dated September 13, 1983 (ST-HL-AE-1003), a copy of which is attached for the Board's convenience.
In September 1983 it was considered feasible to
! construct the vented concrete roof design described above without major schedule impact and for an esti-l j
mated cost somewhat greater than $1,000,000 for two
! units. In view of the current stage of construction, l
8/ In the present design the required vent area is provided by I the design of the sheet metal roof, which provides for it to blow off and vent pressure in the IVC in excess of 0.8 psig.
Egg FSAR Section 3.6.A.2.
1 I
a detailed reanalysis would be necessary to determine the cost and schedule for backfitting such a structure onto the IVC. Design of a new roof would entail complete structural reverification for the IVC because of the added weight and subsequently increased seismic forces from this weight at a high elevation. The instructure response spectra would have to be developed and compared to existing spectra to determine if re-evaluation of the equipment is required. If load effects become too large, the roof may have to be tied to the MEAB by concrete beams. In addition, seismic analysis effects on the MEAB/ IVC interface would have to be reassessed due to the added weights.
Construction of a new roof on the IVC would be difficult because structures adjacent to the IVC are now completed, thereby precluding easy access beside the IVC to elevate concrete forms, reinforcing steel l
and concrete approximately 100 feet in the air.
Erection of a tower crane would probably be required.
In addition, a large quantity of reinforcing steel would have to be drilled and grouted into the existing concrete to effect an adequate bond between the existing and new concrete. Extra restraints on construction would be required because IVC equipment, piping and electrical cables are already installed 1
l
below the roof area. An order of magnitude estimate to remove the existing roof and replace it with a concrete roof is $12.5 million for two units and at least nine months for construction using two shifts.
B. DGB Exhausts A horizontal extension of the exhaust stacks enclosed in a reinforced concrete labyrinth would be required.
Use of refractory concrete would be necessary due to the elevated temperatures of the diesel exhaust. The cost of installing such protection on both units would be on the order of $2 million and each would take approximately eight months to construct.
Another design concept considered was heavy walled exhaust stacks with grated openings. However, this alternative is less desirable because of the difficulty of assessing the potential for crimping of the stack by higher energy missiles.
C. MEAB HVAC Ooeninas The reinforced concrete labyrinth for the HVAC openings on the east side of the MEAB would consist of a canopy over the openings, which would be open at the bottom.
.1
An alternative which appears less desirable is staggered, structural steel beams across the openings.
The quantity of steel and the pressure drop due to reduced opening area appear excessive.
The reinforced concrete labyrinths for the HVAC openings on the roof of the MEAB would consist of one of two alternative configurations. Where HVAC ducts penetrate through the openings the ducts would be encased in reinforced concrete for a sufficient distance along the duct to preclude missiles from impacting the tornado dampors. The other openings would be enclosed with walls and a roof extending beyond two of the walls, as eaves. Openings in the walls below the eaves would allow air to enter.
Construction of missile barriers to protect all of the foregoing MEAB HVAC openings on both units would cost on the order of $2.5 million and take approximately seven months per unit.
For both configurations a feasible alternative is steel structures of design similar to the concrete structures. However the steel structures would be more expensive because of the number of welds that would be involved to develop a sufficiently rigid and missile proof barrier.
.. . ST-HL- AE-1003
. Comparison cf Alternatives fcr Page 1 of 3 IVC Roof Design .
During the meetin with the NRC on July 14, 1983 to discuss the STP proposal to desifin the Iso ation Valve Cubicle structure without a tornado missile
- protect <on roof, the NRC requested that certain supplemental information be provided. Included in this request was a desire on the part of the NRC staff to see a comparison of the various design alternatives which had been considered, including estimates of the cost and schedule implications for each alternative, and advantages and disadvantages of each.
l The five distinct alternatives which were evaluated included the following (some combinations were also investigated):
- 1. Eliminate interior walls separating main steam and main feedwater lines.
l Advantages:
o More volume available for venting.
o More layout space made available.
o HVAC requirements could potentially be simplified, o Standard design approach used in numerous other plants.
,. o Potentially lower overall construction cost.
i
(.
Disadvantages '
o Departure from the full compartmentalization concept.
o Necessity to address the full range of systems interaction issues including pipe break dynamic effects, internally-fire hazards and environmental qualification (EQ) generated missiles, i
( o Component supports at interior locations made more difficult.
o Highest anticipated total cost / schedule impact due to significant change in overall structural design and large exposure to necessary systems interaction protection features and EQ concerns.
~
- 2. Provide localized tornado missile protection to essential components only.
( Advantages o Potentially allow for increased vent area by providing missile barriers I only where needed.
o Potentially allows for maintaining full compartmentalization.
Disady'antages:
o More detailed missile damage assessment necessary, o Localized layout problems likely to occur.
o Local missile barrier requirements likely to require more complicated case-by-case structural design leading to schedule delays in release for construction.
o Pressurization analyses will be more dependent on the postulated location of pipe breaks.
o Complex b6rrier design efforts on a case-by-case basis is anticipated to have a high cost and schedule impact on both design and construction.
(
3008N/0157N
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SfacE:2n8 E ST-HL-AE-1003 Page 2 of 3
- 3. pr vide roof grating as a tornado cissile barrier.
Advantages:
((Y o Maintains full compartmentalization concept.
o With respect to missile barrier design, provides a relatively simple structural design.
o Has good design and licensing precedents.
o If removable, would allow for better operational access for maintenance.
Disadvantages:
o Requires weather protection o Grating thickness required to provide full design basis tornado missile protection is too great to allow adequate vent area. (Note: grating cross-section provides a restriction to flow as a function of mesh spacing and grating bar thickness).
o Additional vent area would need to be provided by further structural design of missile protected openings in side walls.
i o Anticipated to have moderate to high cost and schedule impact related ,
to optimizing structural design to balance venting and barrier protection design features.
- 4. Fully vented complex roof design with missile penetration barriers provided
( Advantages:
o Meets the design basis tornado deterministic protection requirements of R.G. 1.76 and $RP 3.5.
o Meets the vent area requirements for postulated pipe breaks.
o Maintains full compartmentalization concept.
f -
o Provides for the full spectrum of design basis protection against
- [. . external hazards, including non-limiting case sources.
o Although not fully developed, appears to be an achievable design concept.
Disadvantages: -
0 Complicates seismic design sensitivity due to larger massses at higher elevations .
o Creates some layout problems associated with interferences with
- required vent openings.
o More difficult and costly to construct because of complex geometry, and more cumbersome forming and support requirements.
o Restricts operational access because of needed reinforced concrete roof i design.
i o Anticipated to have a lower overall cost and schedule impact than l previously presented alternatives.
1
- 5. Simple roof with no tornado missile barrier design Advantages:
o Maintains full compartmentalization concept o IVC walls meet the intent of R.G.1.76 and SRP 3.5 detern;inistic l protection criteria.
i o Probabilistic assessment using SRP 2.2.3 acceptance criteria justifies the elimination of roof barrier protection.
'(
l-l 3008N/0157N i
.m. m_-
ou%wowe, o Better operational access for maintenance. Pace 3 of 3 o Simp 1:r structural design and construction. -
o Better space envelope fcr int:raal layout consideratitns.
(\ o Lowest cost and least schedule impact likely due to simpler design.
o Design now ready for release to support current construction schedule.
Disadvantages:
o Requires weather protection.
o Requires detailed assessment of non-limiting external hazards, e.g.
hurricane missiles, light aircraft, etc.
o Weather protection must be compatible with postulated pressurization loads. ,
CONCLUSIONS Although definitive cost and schedule estimates have not been developed for each a .ternative, they have been ranked in order of projected descending cost / schedule impact. Alternatives 1, 2 and 3 were considered to have too great an exposure to major cost and schedule impacts; therefore, these options were rejected early in the evaluation process as unacceptable. Only alternatives 4 and 5 were evaluated to the point of developing preliminary designs. Each was considered feasible for implementation without major schedule impact. An order of magnitude estimate of the cost differential for O ** >= two antiaai iadic t i saat it raativ. 4 (ca ai to have a greater than $1,000,000 higher cost for two units, when considering roar) i =aticia t a only the cost for construction of e,more massive, complex concrete structure at a higher elevation.
Alternative 5 involving a simple roof design without tornado missile (4 protection is considered to be fully justified and preferred with respect to minimized cost / schedule impact.
S 1 .
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3008N/0157N O
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. UNITED STATES OF AMERICA NUCLEAR REGUIATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of )
)
HOUSTON LIGHTING & POWER ) Docket Nos. 50-498 OL COMPANY, ET AL. ) 50-499 OL
)
(South Texas Project, Units 1 )
and 2) )
AFFIDAVIT OF R. BRUCE LINDERMAN R. Bruce Linderman, being duly sworn, deposes and says:
- 1. My name is R. Bruce Linderman. My business address is 12440 E.
Imperial Highway, Norwalk, California. I am employed by the Bechtel Western Power Corporation as an Engineering Specialist. A summary of my education and professional experience is attached to my affidavit dated March 11, 1985.
- 2. I participated in the preparation of the foregoing Applicants' Answers to the Board Questions concerning Design of Nonconforming Structures to Withstand Hurricanes and Tornados and I am familiar with the contents thereof.
- 3. I have personal knowledge of the information presented in the answers preceded by my initials (RBL); said answers are true and correct to the best of my knowledge and belief.
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R. Bruce Linderman Subscribed and sworn to before me, a Notary Public in and for Harris County, Texas, this lith day of July,1986.
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Notary PubliU in and'for the State of Texas
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UNITED STATES OF AMERICA NUCLEAR REGUIATORY COMMISSION i
BEFORE THE ATOMIC SAFETY AND LICENSING BOARD J
In the Matter of )
)
HOUSTON LIGHTING & POWER ) Docket Nos. 50-498 OL COMPANY, ET AL. ) 50-499 OL -
) '
(South Texas Project, Units 1 )
and 2) )
AFFIDAVIT OF DONALD H. ASHTON -
Donald H. Ashton, being duly sworn, deposes and t,'ays:
- 1. My name is Donald H. Ashton. My business address is Bechtel Energy Corporation, 5400 Westheimer Court, Houston, Texas. I am employed by Bechtel i as Project Engineer for the South Texas Project. A su
- mar-) of my education and professional experience is attached. .
1
- 2. I participated in the preparation of the foregoing Applicants' Answers to the Board Questions concerning Design of Nonconforming Structuros to Withstand Hurricanes and Tornados and I am familiar with the contents thereof. '
- 3. I have personal knowledge of the information presented in the
- answers preceded by my initials (DHA); said answers are true-and cetreet to the best of my knowledge and belief.
h&H4e&C Donald H. Ashto Subscribed and sworn to before me, a Notary Pihlic in and for Harris j County, Texas, this lith day of July,1986.
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Summary of Education and Professional Experience DONALD H. ASHTON 1 Education: BSME, University of Connecticut MSNE, Purdue University Summary: 2 Years: Project Engineer - Licensing and Nuclear 2 Years: Chief Nuclear / Environmental Engineer 1 Year: Assistant Chief Nuclear Engineer 4 Years: Supervisor, Thermal-Hydraulics and Probabilistic Risk Assessment Groups, Nuclear Staff 5 Years: Engineer, Thermal-Hydraulics Analysis, Reliability Evaluations-Nuclear Experience: Mr. Ashton is currently a Project Engineer on the South Texas Nuclear Project. He has lead responsibility for project licensing activities, including maintenance of the FSAR, review and approval of licensing submittals, and investigation and reporting for 10CFR50.55(e) items. In addition he directs the project equipment qualification program and coordination of the NSSS vendor contract.
Previously, he provided project engineering direction for the design of mechanical systems, equipment and material specifications and support of construction completion.
Mr. Ashton was previously the Chief Nuclear / Environmental Engineer for the Houston Area Office. In this capacity he had technical review and administrative responsibilities for the nuclear and environmental disciplines. The duties of these groups included coordination of licensing (including FSAR preparation), system design responsibilities, preparation of applications for pertinent state and federal permits, and analysis activities in support of fossil and nuclear power plants.
In addition to responsibilities as Assistant Chief Nuclear Engineer in Caithersburg, he was also designated to coordinate that divisions program for Reliability Analysis and Probabilistic Risk Assessment. The scope of this effort included system availability analyses and analyses in response to degraded core considerations for nuclear plants.
Mr. Ashton was previously the supervisor of the Thermal-Hydraulics Group of the Nuclear Engineering Department. He was responsible for planning and coordinating the technical and licensing support of nuclear power plant engineering groups in the areas of heat transfer analysis, analysis of combustible gas concentrations, and analysis of thermal and hydraulic transients and pipe break effects.
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DONALD H. ASHTON Page 2 Experience: In previous assignments he was responsible for the revied and evaluation of recovery techniques as part of the Three Mile Island Recovery Program, performed post-14CA dose calculations and shielding analyses for various nuclear power plants and was involved in fault tree and A
computer-aided analyses of emergency power systems.
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, UNITED STATES OF AMERICA NUCLEAR REGUIATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of )
)
HOUSTON LIGHTING & POWER ) Docket Nos. 50 498 OL COMPANY, ET AL. ) 50-499 OL
)
(South Texas Project, Units 1 )
and 2) )
AFFIDAVIT OF ANTHONY J. MARK Anthony J. Mark, being duly sworn, deposes and says:
- 1. My name is Anthony J. Mark. My business address is 12440 E.
Imperial Highway, Norwalk, California. I am employed by the Bechtel Western Power Corporation as an Engineering Supervisor. A summary of my education and professional experience is attached.
- 2. I participated in the preparation of the foregoing Applicants' Answers to the Board Question: concerning Design of Nonconforming Structures to Withstand Hurricanes and Tornados and I am familiar with the contents thereof.
- 3. I have personal knowledge of the information presented in the answers preceded by my initials (AJM); said answers are true and correct to the best of my knowledge and belief.
Anthony J. 1% ark Subscribed and sworn'to before me, a Notary Public in and for Harris County, Texas, this lith day of July,1986.
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l Summary of Education and Professional Experience i ANTHONY J. MARK I
Education: BS, Biological Sciences, University of Southern California; PhD, Cellular and Molecular Biology, University of Southern California Additional Coursework: Reliability and risk assessment engineering, fire and explosion hazards evaluation, dispersion meteorology, supervisory management, project management Summary: 2 1/2 Years: Engineering Supervisor, Reliability and Risk Assessment Group 1/2 Year: Bechtel Senior Engineer assigned to the Reliabi-lity and Risk Assessment Group, performing various duties involving nuclear licensing, safety evaluation, and probabilistic risk assessment 1 Year: Bechtel Project Task Leader and Nuclear Engineering Group Supervisor (Nuclear ECS) on a nuclear power plant Early Site Review Project for Public Service Company of New Mexico 3 Years: Bechtel Engineer, Nuclear and Environmental Group Technical Staff, responsible for perform-ing radiological impact assessments, risk analyses, and offsite hazard evaluations (fires, explosions, toxic gas releases) for nuclear power plant Environmental and Safety Analysis reports 1 1/2 Years: Bechtel Engineer, Nuclear and Environmental Group Technical Staff, responsible for prepara-tion of licensing documents for nuclear and fossil-fuel power plants 4 1/2 Years: Project Manager with the consulting firm of
- Dames and Moore in Santa Barbara, California Experience
- Dr. Mark is currently the Engineering Supervisor of the Reliability and Risk Assessment Group of Bechtel Western Power Corporation. In this capacity, he is responsible for the performance of reliability and risk assessment evaluations, and the management of multidisciplinary studies involving various practical engineering applications of probability and statistics.
He served as Technical Coordinator of Bechtel Western Power Corporation's multidisciplinary seismic task force which is developing improved methodologies for quantifying the seismic fragilities and seismic risk of nuclear power plants.
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ANTHONY J. MARK Page 2 He is also serving as Bechtel's technical representative on the Nuclear Construction Issues Group (NCIG) Sampling Plan Subcommit-tee, which is developing a generic statistical sampling plan for use with NCIG Visual Weld Acceptance Criteria (VWAC) that were recently endorsed by NRC. In addition, he and his staff are exploring practical uses of information developed in nuclear power plant Probabilistic Safety Analyses, including evaluation of changes in plant risk associated with extending technical specifi-cation outage durations, and development of artificial intelli-gence systems to aid operators in diagnosing and recovering control of the plant after a nuclear reactor accident. Other work performed under his supervision includes reliability and availability engineering evaluations, hazards and risk assessment, and practical applications of probabilistic decision theory.
While employed with the consulting firm of Dames and Moore, Dr.
Mark had project management responsibilities and technical responsibility for the performance of oil spill risk analysis studies for numerous offshore oil development projects, including the largest such project ever proposed in the United States (Exxon Santa Ynez Unit Development).
During his previous employment with Bechtel, Dr. Mark served as the Nuclear Engineering Group Supervisor and Project Task Leader for a nuclear power plant Early Site Review project for the Public Service Company of New Mexico. Prior to this, he served as a member of the Nuclear and Environmental Group Technical Staff, where he performed radiological dose calculations and offsite hazard evaluations (fires, explosions, and toxic-gas releases) for numerous nuclear power plant Safety Analysis Reports.
During doctoral studies at the University of Southern California j prior to joining Bechtel, Dr. Mark developed a series of computer codes to statistically predict the most thermodynamica11y stable conformations of proteins and nuclear acids from a knowledge of their primary sequence.
Professional Affiliations:
! Member, Phi Sigma Society Member, Society for Risk Analysis l
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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of )
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HOUSTON LIGHTING & POWER ) Docket Nos. 50-498 OL COMPANY, ET AL. ) 50-499 OL
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(South Texas Project, Units 1 )
and 2) )
CERTIFICATE OF SERVICE I hereby certify that copies of the letter to the Atomic Safety and Licensing Board from Alvin F. Gutterman dated July 14, 1986, and Applicants' Answers to the Board Questions Concerning Design of Nonconforming Structures to Withstand Hurricanes and Tornados have been served on the following individuals and entities by deposit in the United States mail, first class, postage prepaid on this 14th day of July 1986.
Charles Bechhoefer, Esq. Brian Berwick, Esq.
Chairman, Administrative Judge Assistant Attorney General Atomic Safety and Licensing For the State of Texas Board Panel Environmental Protection U.S. Nuclear Regulatory Division Commission P.O. Box 12548, Capitol Station Washington, D.C. 20555 Austin, TX 78711 Dr. James C. Lamb, III Kim Eastman, Co-coordinator Administrative Judge Barbara A. Miller 313 Woodhaven Road Pat Coy Chapel Hill, NC 27514 Citizens Concerned About Nuclear l Power Frederick J. Shon 5106 Casa Oro Administrative Judge San Antonio, TX 78233 U.S. Nuclear Regulatory Commission Lanny Alan Sinkin, Esq.
Washington, D.C. 20555 Christic Institute 1324 North Capitol Street, N.W.
Mrs. Peggy Buchorn Washington, D.C. 20002 Executive Director Citizens for Equitable Oreste Russ Pirfo, Esq.
Utilities, Inc. Robert G. Perlis, Esq.
Route 1, Box 1684 Office of the Executive Legal Brazoria, TX 77422 Director U.S. Nuclear Regulatory Commission l
Washington, D.C. 20555 i
Atomic Safety and Licensing Board U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Atomic Safety and Licensing Appeal Board U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Docketing and Service Section Office of the Secretary U.S. Nuclear Regulatory Commission Washington, D.C. 20555 l
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