ML20199C639
| ML20199C639 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/14/1997 |
| From: | SOUTHERN CALIFORNIA EDISON CO. |
| To: | |
| Shared Package | |
| ML20199C419 | List: |
| References | |
| NUDOCS 9711200076 | |
| Download: ML20199C639 (9) | |
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1 Attachment A Existing Pages UFS AR, Section 3.5, " Missile Protection" 9711200076 971114 PDR ADOCK 05000361' P
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'3.5.1.6.2.4 (Cont.)The appropriate values'of A were taken from references:71 and-11._--The decay-constant;for commercial aviation was' corrected to consider it
-that the aircraft-were flying-at a lower altitude near the San Onofre-site'.:
The-values used for A were 2.0 mi-8 for the general single engine and twin engine categories 1 mi'2= for military jet and helicopter. and 2.67 rdJ' for the E
. air carrier 1and other high-speed jet categories. The appropriate valuer for the, annual number of flights and crash density are given in table 3.5-11.
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Crash Probabilities. The probability'of striking'any-
' safety-related portion of the plant is given in tablo 3.5-11 for the three-aircraft categories. With the exception of military helicopters, which
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assumed no skad,'the probability is the sum of the-impact and skid components.
All of these probabilities are seen to be less than 10".
It is concluded that aircraft opeLations in the vicinity of the San Onofre site result in no credible Sazard.
3.5.2 SYSTEMS TO BE PROTECTED 3.5.2.1-General The sources of missiles which, if generated, could affect the safety of the plant are considered in subsection 3.5.1.
A tabulation of safety-related structures and equipment, is provided in Appendix 3.2A.
Figure 3.5-9
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identifies safety-related penetrations for the auxiliary building and fuel handling building that require tornado missile protection.
Figures 3.5-2 tnrough 3.5-7 identify safe shutdown systems and safety-related plant areas within the turbine misrile strike zone.
3.5.2.2 Barriers for Interna 11v Generated Missiles (Outside and Inside thg 2
containmant) 1 Safety-related structures and equipment are protacted from internally l
generated missiles by the separation and independence inherent to redundant systems or by physical barriers as listed in tables 3.5-1 and 3.5-2, 3.5.2.3 Barriers for Missiles Generated by Natural Phenomena (Tornado) f
-A tabulation of protected components and the structures, shields, and barriers-that are designed to provide protection from tornado-generated missiles is
~ iven in table 3.5-12.
The missile barriers indicated are designed utilizing g
the procedures given in subsection 3.5.3.
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2/92 3.5-46 Revision 8 4.-..
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Table 3.5-12 MISSILE BARRIERS FOR TORNADO MISSILES Protected components Missile Barrier Reactor coolant syscem and other Containment structure, primary and protected equipment inside secondary shields, refueling cavity containment wall, internal structures and beams Control room and protected Auxiliary building electrical, inr.trumentation, control, piping, mechanical and ventilation equipment in auxiliary i
building Emergency core cooling, spray boron Safety equipment building and 4.ddi ti on, cooling water, internal structures ve nt il a t i o'n, electrical, instrumentation, control, and other protected equipment in safety equipment buildina Spent fuel pool and other protected Fuel handling building and fuel pool equipment in fuel handling building wall Emeraency diesel generators Diesel generator room walls and roof Diesel fuel oil systems Missile-resistant enclosures for underground fuel storace tanks Main steam line isolation valves Main steam enclosure building walls and roof saltwater pumps Intake structure Auxiliary feedwater pumps Misaile-resistant enclosure Conden; ate storage tank' Hissile-resistant enclosure
'Two ladders (per Unit), which are not protected from tornado missiles, provide operator access to the manual valves used to cross-connect the Condensate Storage Tanks In the highly unlikely event that one or both ladder (s) is damaged, there will be sufficient tine available (approximately 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />) to facilitate operator access to the CST crosstie valves.
6/94 3.5-48 Revision 10 a
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l 3.5.3 BARRIER DESIGN PROCEDURES
' Missile-resistant barriers and structures are designed to withstand and absorb missile impact loads without being perforated in order to prevent danage to protected. components. The procedures employed in design of missile-resistant b ir rier s for local effects are described in Section 2 of BC-TOP-9A"U and EPRI RP-399.
- The procedures used to predict the overall response of the barrier and portions thereof to missile impact are described in Sections 3 and 4 of BC-TCP-9A.""
Due to splintering upon impact, the energy imparted to the targets by the utility pole and the 4" x 12" plank (Tanle 3.5-6) will be a small fraction (25v) of their initial energy. Table 5-1 of EPRI RP-399"" provides test data ior a 12" diameter steel pipe and a 13.5" diameter utility pole (Test No. 6&
12 respectively).
For almoct identical velocities, the load imparted to the test slab by the utility pole is less than 50% of that from the pipe.
The utility pole is twice as heavy as the pipe thus indicating a four fold reduction in energy due to splintering.
No tests were performed for the 4" x 12" plank, however, it can be concluded that the splintering of the plank will be more severe than that of the utility pole as the velocity of the plank is much higher than utility pole's test velocity (322 fps versus 203 fps),
based on these test results, only 25% of the calculated strain energy should be used for the utility pole and the 4" x 12" plank.
However, as an additional design conservatism, 50s of the strain energy for the tility pole is considered in the barrier designs.
The barriers provided for protection against tornado-generated missiles are t ypically the reinforced concrete walls (1-foot 6-inch thick minimum) and roof slabs (1-foot 2-inch thick minimumi of the safety-related structures.
These thicknesses prevent perforation and sustain the impact without concrete spalling on the interior surfaces.
In addition, steel grids or framed steel plates (3/4-inch minimum thickness) are provided as covers for safety-related openings.
These covers present missile perforation and experience structural deflections which are restricted by design so as not to impair the intended safety function of each opening.
One of these covers is the set of front entry doors (AC201) to the control room lobby.
These doors are designed as missile barriers and are normally held in an open position.
Upon initiation of a severe weather warning, the station is notified by the SCE Energy Control Center and station personnel will then close these r.ussile doors.
In addition to AC201, the bullet resistant doors which provide access to rooms 127A and 127B on the east side of the Radwaste building (AR307 and AR311),
provide tornado missile protection.
These doors are n;tmally closed and are protected by 12" concrete enclosures which are open to the south on Unit 2 and north on u,.it 3.
The concrete enclosures protect the doors from direct minsile sttikes.
Each door protects the CCW make-ut pumps and valves (located in room 127A and 127B) against oblique toraado missile strikes and spalled concrete from the enclosure.
These doors are less than.3/4" steel thickness, but would not be perforated by the worst case oblique missile strike which could reach the doors.
An oblique missile strike is extreme y unlikely due to the configuration of the concrete enclosures and the recessed doors.
These doors are normally closed; nonetheless, upon in' iation of a severe weather warning, station personnel will verify that these noors are closed.
3/96 3.5-49 Revision 11
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Attachment B Proposed Pages UFSAR, Scction 3.5, " Missile Protection" 1
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3.5.1..G.2.4 (Cont.)The appropriate values of A were taken from references 7
'and 11.
The deca y cor.s t ant for commercial aviation was corrected to consider that the aircraft were flying at a lower altitude near the San Onofre site.
The values used foi A were 2.0 mi" for the general single engine and twin engine categories I h:i" for ndlitary jet and helicopter and 2.67 mi for the d
air carrier and other high-speed jet categories. The appropriate values for t h.e annual nunber of flights and crash density are given in table 3.5-11.
3.5.1.6.2.4 Crash Probabilitieg. The probability of striking any safety-related portion of the plant is given in table 3.5-11 for the three aircraft <ategories.
With the exception of military helicopters, which assumed ra skid, the probability is the sum of the impact and skid components.
All of t'iest probabilities are seen to be less than 10" It is concluded that air: raft operations in the vicinity of the San onorre site result in no atedible harard.
3.5.2 SYSTEMS TO BE PROTECTED 3.5.2.1 General The sources of missiles which, if generated, could affect the safety of the plant are considered in subsection 3.5.1.
A tabulation of safety-related structures and equipment, is provided in Appendix 3.2A.
Figure 3.5-9 identifies safety-related penetrations for the auxiliary building and fuel handling building that require tornado missile protection.
Figures 3. 5-2 through 3.5-7 identify safe shutdown systems and safety-related plant areas within the turbine missile strike zone.
3.5.2,2 Ea r r ie r s for Internally Generated Missiles (Outside and Inside the containment)
Safety-related structures and equipment are protected from internally generated missiles by the separation and independence inherent to redundant systems or by physical barriers as listed in tsbles 3.5-1 and 3.5-2, 3.5.2.3 ILuJiers for Missil?s Generated b;g Natural Phenomena (To rn vto )
A tabulation of c::itical components and the structures, shields, and barriers l
that are designed to provide protection from tornado-generated missiles is given in table 3.5-12.
The missile barriers indicated are designed utili:ing the procedures given in subsection 3.5.3.
2/92 3.5-46 Revision 8
. y Table 3.5-12 MISSILE B ARRIERS FOR TORNADO MISSILES Protected Critical C,omponents Missile Barrier l 5 *fP I Reactor coolant system and other protected Containment structure, primary and critical equipment inside containment secordary shields, refueling cavity wall, internal stmetures and beams Control roorr and protected critical electrical, Auxiliary building l
instrumentation, control, piping, mechanical and ventilation equipment in auxiliary building Emergency core cooling, spray boron Safety equipment building and internal addition, cooling water, ventilation, electrical, structures instrumentation, control, e ' other protected critical equipment in safety equipt..ent 5*ff I building Spent fuel pool and other protected critical Fuct handling building and fuel pool wat?
l59,i equipment in fuel handling building Emergency dicsci generators Diesel pencrator room walls and roof Diesel fuel oil systems htissile-resistant enclosures for underground fuel storage tanks hiain steam line isolation valves Main ricam enclosure building walir and roof Saltwater pmnps intake structure Auuliary feedwater punys Missile-resistant enclosure
('ondensate storage tank' Missile-resistant enclosure
'Two ladders (per Unit), which are not protected from tornado missiles, provide operator access to the manual vahes used to cross connect the Condensate Storage Tanks. In the highly unlikely event that one or both ladder (s) is damaged, there will be sullicient time available (approximately 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />) to facilitate operator access to the CST crosstie valves.
6/94 3.5-48 Revision 10 4
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- 3. 5. 3 -
. BARRIER DESIGN PROCEDURES'
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JMissile-resistant barriers and structures are designed to with' stand and absorb
- missile impact loads without being. perforated in order to prevent damage to' protected components. The procedures employed in design of missile-resistant i
barriers for local ef fects are described in Section'2-of BC-TOP-9A"" and 'EPRI
)
RP.-399 "k
The procedures used to predict the overall response of the barrier j
~
i and_partions thereof to missils impact are described in Sections 3 and-4 of bC-TOP-9A.""
Due to splirtering upon impact, the energy imparted to the targets by the utility pole and the 4" x 12" plank (Table. 3. 5-6) will be_a small fraction (25M of their initial energy. Table 5-1 of EPRI RP-399F" provides test data for a 12" diameter steel pipe and a 13.5" diameter. utility pole (Test No. 6&
12 respectively).
For almost identical vslocities, the load imparted to the test slab by the utility pole is less than'50% of that from the pipe.
The utility pole is twice as heavy as the pipe thus indicating a four fold reduction in energy due to splintering. No tests were performed for the' 4" x 12" plank, however, it can be concluded that the splintering of the plank will be more severe than that of the utility pole as the veloc1ty of the plank is much higher than utility pole's test velocity (322: fps versus 203 fps).
Based on these test results, only 25% of the calculated strain energy should be used for the utility pole and the 4" x 12" plank.
However, as an additional de:ign conservatism, 50% of the strain energy for the utility pole is censidered in the barrier designs.
4 The barriers provided for protection against tornado-generated missiles are ty;1cally the reinforced concrete walls (1-foot 6-inch thick ndnimum) and roof slabs (1-foot 2-inch thick minimme) of the safety-related structures.
These thicknesses prevent perforation and sustain the-impact without concrete spalling on the interior surfaces.
In addition, steel grids or frimed steel plates (3/4-inch minimum thickness) are provided as covers for safety-related i
opeaings. These covars prevent ndssile perforation and experience structural deflections wnich are restricted by design so as not to impair the intended safety function of each opening.
One of these covers is the set of front entry doors (AC201) to the control room lobby. These doors are designed as missile barriers and are normally held in an open position. Upon initiation of a severe weather warning, the Lcation is notified by the SCE Energy Control Center'and station personnel will then close these missile doors, ytissi'le-resistant'(b'arrier pareino n equiradswheinithedtotalfprobabilityl(per uait;per year)fot1damageAo exposedferitica19 components <due dora missile
' strike:is lessythan 10'3.: TableJ3L5613(listslexposedreritical compcnentsian'd the probability of churiage.c ; Operat' rLaction9(e.qMis~ olation:ofj piping sys.tems gTg o
upon? receipti of a5 Severe WeathM Warning); maylbeycreditedjaolthat; soine J
-equipmentiwillinotfbe konsidered,as Mrttli:ni, component 4 It; addition to AC201, the bullet resistant doors which provida access to rooms 127A and 127B on the east side of the Radwaste Building (AR307 and AR311).,
provide tornedo missile protection. These doors are normally closed ind are protected by 12". concrete enclosures which are op.n to the south on Unit 2 and north on Unit 3.
The concrete enclosures protect the doors from direct missile strikes.
Each door protects the CCW make-up pumps and valves (located in room 127A and 127B) against oblique tornado missile strikes and spalled concrete from the enclosure. These doors are less than 3/4" steel thickness, but would not be perforated by the worst case oblique missile strika which h
could reach ~the doors. An oblique missile strike is extremely unlikely due to the configuration of the concrete enclosures and the recessed doors.
These doors are normally closed; nonetheless, upon initiation of a severe weather warning, station personnel vill verify that these doors are closed.
3/96 3.5-49 Revision 11 1
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Table 3.5-13 Annual Probability of Damage to Critical Components Exposed to Tornado-Missiles (per Unit)
Annual Area Damage item Descriptian Location ft; Probabilit" i
Piping and valves Exposed portions 2000 0.03 x 10" associated with inside twfueling auFiliary Water Storage Tunk feodwater pump enclosures.
auction, discharge and miniflow.
2 condensate Exposed portions in 300 0.01 x 10" inventory required ano around for safe shutdown.
Condensate Storage T-120 enclosure up to valves liv-5715 and 1414MUO92.
3 Piping, tubing and Exposed portions in TOO 0.04 x_10" l
valvos ancociated yard area between with component tank building and coolin. water main steam isolation backup nitrogen valve area, systom.
4 Protected Portions exposed by 1200 0.1 x 10' electrical, seismic gaps between Instrumentation, containment, safety control, piping, equipment, fuel
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mechanical and handling, and ventilation auxiliary buildings; h([ l '
equipment.
electrical tunnels; saltwater cooling pipo tunnel; and main steam isolation
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valve area.
5 Protected Portions exposed by 100 0.01 x 10" electrical miscellaneous equipment.
oraanings in auxiliary btV11 ding west wall and roof.
6 Subtotal 0.2 x 10" Total"'
<, 1.0 x 10"
"' Missile-resistant barriers are not required when the cumulat.tve annual probability of damage per unit to exposed critical components due to a mirsile strike is less than 1.00 E-7.
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