ML17258A191
| ML17258A191 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 09/28/1981 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Maier J ROCHESTER GAS & ELECTRIC CORP. |
| References | |
| TASK-03-04.A, TASK-3-4.A, TASK-RR LSO5-81-09-066, LSO5-81-9-66, NUDOCS 8109300307 | |
| Download: ML17258A191 (11) | |
Text
September 28, 1981
'iO--
g J'r Docket Ho. 50-244 LS05 09-066 t/lr. John E. thaier Vice President Electric and Steam Production Rochester Gas
& Electric Corporation 89 East Avenue Rochester, llew York 14649
Dear l'ir. Haier:
SUBJECT:
SYSTEtlATIC EVALUATIOIJ PKOGRiN TOPIC III-4.A, TORIJADO tiISSILES - GItJ>JA Enclosed is a copy of our draft evaluation of Systematic Evaluation Program Topic III-4.A.
The evaluation identifies major portions of safety related systems which are inadequately protected from tornado missiles.
Decisions concerning protective measures required for these systems will be made during the integrated assessment.
You are requested to examine the facts upon which the staff has based its evaluation and respond either by confirming that the facts are correct, or by identifying errors and supplying the corrected information.
Me encourage you to supply any other material that might affect the staff's evaluation of this-topic or be significant in the inteorated assessment of your facility.
Your response is requested within 30 days of receipt of this letter. If no response i's received within that time, we will assume that you have no comments or corrections.
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Sincerely, Encl osure:
As stated A
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/81 Dennis H. Crutchfield, Chief Operating Reactors Branch No.
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NRC CORM 3l8-RO/BO) NRCM 9240 OFFICIAL RECORD COPY a USGPO; 1980-329.jh24
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Mr. John E. Maier CC Harry H. Voigt, Esquire
- LeBoeuf, Lamb, Leiby and MacRae 1333 New Hampshire
- Avenue, N.
W.
Suite 1100 Washington, D. C.
20036 Mr. Michael Slade 12 Trailwood Circle Rochester, New York 14618 Ezra Bialik Assistant Attorney General Environmental Protection Bureau New York State Department of Law 2 World Trade Center New York, New York 10047 J effrey Cohen New York State Energy Office Swan Street Building Core 1, Second Floor Empire State Plaza
- Albany, New York 12223 Director, Bureau of Nuclear Operations State of New York Energy Office Agency Building 2 Empire State Plaza
- Albany, New York 12223 Rochester Public Library 115 South Avenue Rochester, New York 14604 Supervisor of the Town of Ontario 107 Ridge Road West
- Ontario, New York 14519 Resident Inspector R. E. Ginna Plant c/o U. S.
NRC 1503 Lake Road
- Ontario, New York 14519 Mr. Thomas B. Cochran Natural Resources Defense Council, Inc.
1725 I Street, N. W.
Suite 600 Washington, D. C.
20006 U. S. Environmental Protection Agency Region II Office ATTN'IS COORDINATOR 26 Federal Plaza New York, New York 10007 Herbert Grossman, Esq.,
Chairman Atomic Safety and Licensing Board U. S. Nuclear Regulatory Comnission Washington, D. C.
20555 Dr. Richard F. Cole Atomic Safety and Licensing Board U. S. Nuclear Regulatory Comaission Washington, D. C.
20555 Dr.
Emmeth A. Luebke Atomic Safety and Licensing Board U. S. Nuclear Regulatory Commission Washington, D. C.
20555
R E. Ginna, Nuclear Power Station III-4. A TORNADO MISSILES I;
INTRODUCTION General Design Criteria 2 and 4 of Appendix A, 10 CFR Part 50, require, r espect-ively, that structures,
- systems, and components important to safety be designed to withstand the effects of natural phenomena, and also be protected from missiles originating from events and conditions outside the plant.
Tornado missiles, i.e., objects and debris blown before tornado winds, are hazards which may be considered as included in either or both of these criteria.
Review topic III-4.A directs the evaluation of the plant's protection against these hazards to determine whether or not it is sufficient to assure:
1.
The integrity of the reactor coolant pressure
- boundary, 2.
The capability to shut the reactor down and maintain it in a safe shutdown condition, and 3.
The capability to prevent accidents which could result in offsite exposures in excess of the dose guidelines'f 10 CFR Part 100.
II.
REV IEM 'CR ITER ION A structure,
- system, or component is considered to be adequately protected from a postulated missile if either it itself or a structure which surrounds.
it is sufficient to stop that missile without per,oration or collapse.
No credit is given to masonry block walls for tornado missile protection.
III.
RELATED SAFETY TOPICS Topic II-2.A, "Severe 'Aeather Phenomena".
describes the tornado character-istics for the plant.
Topic III-2, "'rlind and Tornado Loadings" reviews the capability of the plant structures, systems and components to withstand wind
~.'oadirigs.
Topic VII-3, "Systems Required for Safe Shutdown" reviews th'ose systens needed to achieve and maintain the plant in a safe shutdown condition.
IV.
REVIEW GUIOANCE Regulatory Guide 1.78 defines the characteristics of the tornadoes to be used as design bases at sites within the coterminous United States.
WASH-1300, "Technical Basis for Interim Regional Tornado Criteria," referenced by that guide, contains more detailed information concerning tornado incidence and
/
I severity.
Regulatory Guide 1.117 contains instructions by which structures,
- systems, and components important to safety can be identified in any plant design.
Standard Review Plan (SRP) 3.5.1.4, Revision 1, "Missi les Generated by Natural Phenomena," lists objects which may be postulated to be hurled as missiles by tornado winds.
The diversity of objects, and the velocities and altitudes they are to be postulated to attain as missiles, are given in this plan for each of three regional design basis tornadoes,
- and, since the review has been revised, for each of three time intervals in which a construction permit application was filed.
For a plant, which, 'like Ginna, is located in tornado Region I and for which an application for a construction permit was made prior to 1973, the appropriate design basis missiles are:
l.
A steel rod, 1-inch diameter and 3-feet long, weighing 8 pounds, striking end-on at 317 feet/second (97 meters/sec),
which corresponds:to 6(C of 360 MPH wind velocity.
2.
A wooden utility pole, 35-feet long, weighing 1490 pounds, striking end-on at 211 feet/second (64 meters/sec) at elevations less than 30 feet ab'ove
'he highest grade level within 1/2 mile,of the plant.
This'orresponds to 40K of 360 MPH wind velocity.
w3 As noted in SEP Topic II-Z.A tornadoes are significantly 1ess frequent and less severe in the vicinity of Ginna than in most of Tornado Region I.
The 1
design basis tornado at Ginna has, therefore, been assigned a maximum wind speed of 250 mph (ill meters/sec).
For this wind speed, the appropriate design basis missile velocities given above are revised to:
. 1.
Steel rod, 605 of 250 mph, or 219 feet/second (67 meters/she).
2.
Wooden utility pole, 40% of 250 mph, or 146 feet/second (45 meters/sec).
V.
EYALUATION A.
Structures s stems and corn onents important to safet The reactor is housed within a steel-reinforced concrete containment building approximately a meter thick, surrounded by a steel-reinforced concrete structure, largely below grade, which is surmounted by steel structures with sheet metal siding.
The screenwell house is a similar steel superstructure on a concrete
- basement, while the diesel generator building is a steel structure attached to the main plant buildings.
The missile barrier protection described in I.2, above, is required to assure capacity to achieve and maintain saf shutdown of the reactor.
The systens needed for this capacity are treated in topics V-10.B, Y-ll.A, V-ll.B, VII-3 and IX-3, and reported in "SEP Review of Safe Shut-down Systems (Rev. 1)," dated November 14, 1980.
These systems are:
1.
Auxiliary feedwater system 2.
Standby auxiliqry feedveter systems.
3.
>lain steam systen out to atmospheric dump valves 4.
Service water system
5.
Chemical volume control systan 6.
Component cooling system 7.
Residual heat removal system 8.
Emergency power supply, including transformers.
The missile barrier protection required in I.3, above, in addition to I
the reactor coolant pressure boundary in I.l, and the eight systems above, further include the control room and its instrument and control communications with the other systems and structures listed, and.the spent fuel pool.
B.
Missile barriers which meet current requirements Although Ginna was designed and built prior to the development of the Standard Review Plan, a portion of the plant has sufficient strength to meet current (since June, 1977) missile protection requirements.
This portion consists of the containment building and the lower concrete structure of the control room, auxiliary, and'intermediate buildings.
( The intermediate level of the auxiliary building is protected from above by the upper level concrete floor) Safety systems housed in this portion are the reactor coolant pressure
- boundary, the redundant auxiliary feedwater systems,.the residual heat removal
- system, and the battery room.
C.
Missile barriers which meet re-1973 re uirsnents Structures and systems important to safety which provide adequate protection or are protected against the two missile impacts in IV, above',
are:
1.
Condensate storage tank 2.
Control room 3,
Main steam line A I
4.
All main s.earn line isolation valves
s
~ 5.
All main steam line safety relief valves 6.
The sides of the spent fuel pool.
s The licensee has confirmed that the masonry block walls which protect the control room from tornado missiles have been covered by 3/8" thick armor plate.
D.
Safet e ui ment not rotected b
ade uatemissile barriers The steel siding structures contain the remaining structures,
- systems, and components important to safety, i.e.,
those not mentioned in V.B or V.C, above.
These are:
1.
Component cooling system 2.
Refueling water storage tank*
3.
Electrical buses 14, 17 and 18 4.
Service water system 5.
Diesel generators and their fuel supply*".
6.
Relay room 7.
- In addition to being required for safe
- shutdown, loss of this component could flood the upper floor of the auxiliary building or drain to lower levels;.
where safety related equipment is located.
- Vulnerable due to the 10' 7'orrugated sheet metal rolling door; intake and exhaust structures would be subject to damage from missile impact and collect debris.
8.
The top surface of the 'spent fuel pool is open and therefore the internals are exposed.
9.
Boric acid tanks***
I I
The ability of the steel siding surrounding these components and systems to withstand tornado wind loadings and pressure differentials is being investigated in SEP Topic III-2.
It is expected that the siding will not be able to withstand large loadings;
- however, even if the siding remained attached to the.
structural steel, its ability to withstand missile impact would be negligible.
Therefore, the only missile protection existing for the above items, is the strength of the components themselves.-
- The boric acid tanks located in the auxiliary building on floor elevation 271'-0" extend to elevation 283'-0" and are protected on all sides by an 18" thick concrete wall with a top elevation of 286'-0".
Any missile
'triking the tanks would have to enter from above and therefore, any penetration of the tanks would most likely occur in the upper portion.
The acid is 12Ã boric acid by weight and would not react significantly with concrete or steel in the short amount of time these materials would be exposed to the acid before being cleaned up.
The concern regarding the boric acid tanks is flooding.
The walls have two entrances through them and therefore will not function as dike walls.
While not required for safe
- shutdown, loss of this component could flood the upper floor of the auxil,iary building or drain to lower levels, possibly affecting equipment located there.
The licensee should provide a,conservative estimate of the amount of acid which may be released and describe the consequences of such a release.
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VI.
CONCLUSIONS Our evaluation indicates that major portions of the systems important to safety are inadequately protected from tornado missiles.
The need for improvement of this protection will be evaluated during the integrated assessment for Ginna.
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