ML17258A755
| ML17258A755 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 01/07/1981 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Maier J ROCHESTER GAS & ELECTRIC CORP. |
| References | |
| TASK-02-01.C, TASK-06-08, TASK-6-8, TASK-RR LSO5-81-01-005, LSO5-81-1-5, NUDOCS 8102040736 | |
| Download: ML17258A755 (15) | |
Text
N I
}
UNITED
- a. A+a afUCLEAR REGULATORY COM ISSION WASHINGTON, O.a. 20555 jgfggpf $
11$ /I 7 I,IIF JAhf 0 7 tggg DISTRIBUTION:
NRC PDR GCwalina LPDR CBerlinger TERA
~'DEisenhut NRR Reading RPurple SEB Reading JRoe Nr. John Naier OELD RDiggs Vice President OI8E (3)
TNovak Rochester Gas 8 Electric Corporation ACRS (16)
RTedesco 89 East Avenue NSIC, JBuchanan GLainas Rochester, New York 14649 JHeltemes, AEOD JWetmore WRussell
Dear Nr. Naier:
DCrutchfield
SUBJECT:
GINNA -'SEP TOPICS VI-8 AND II.1.C By letter dated November 24, 1980, you requested that we provide a copy of the draft evaluation of SEP Topic VI-8, "Control Room Habitability" which would document the work performed to date on the Ginna control room habitability issue.
Accordingly, we have enclosed a copy of our draft evaluation which was written subsequent to the site visits in September 1978 and Narch 1979.
Therefore, the draft should reflect the total effort expended on that issue.
gF,R REGI/
O aa Docket No. 50-244 4 s6<-F/-c-eeK I would like to emphasize that the material provided is a draft which has not been reviewed and approved by the SEP.
As pointed out in our letter to you dated October 1, 1980, the topic was deleted from the SEP because of its inclusion in the TNI action plan.
Therefore, the SEP review of this issue was halted prior to issuing the topic evaluation.
I would also like to point out that the existence of this evaluation does not relieve you of the requirements and schedules provided for in NUREG-0737, "Clarification of TNI Action Plan Requirements."
You will note that the enclosed evaluation of Topic VI-8 recommends that you take corrective action within the next four months (i.e.
3 to 6 months) to reduce an existing ammonia hazard and to consider further means to reduce the potential thyroid dose to reactor" operators following a
- LOCA, You also requested a copy of the SEP draft evaluation of SEP Topic II,1,C, "Potential Hazards or Changes in Potential Hazards Due to Transportation, Institutional, Industrial and Nilitary Facilities."
The draft topic assess-ment has not been corn will forward the topic assessment upon,its completion for your ent in accordance with procedures developed for SEP.
(
Sincerely, SX020@07gg OFFICE)
SURNAME/
DATEP SEPB:DL S
Ka:dk I j5f'/80'-'"
CB rlin er
~2'>~i8 0 --.
closur'e:
See W u
'"'VV
ppepati g Reactors Bl"
""""DiVisto "of"L'jc'enctrrg nQftB45: DL:PN
'Snasder
"'l'/"<'81"""" 0:C D
tc field
'Tfg'/ST"'"
NRC FORM 318110/80) NRCM 0240 OFF)C]AL RECORD COPY USGPO: 1999-929.824
J I ~
T
$ 4 I eg'"
~ l ~ f' If"
~ If lgII t
~ I
gy8 AKOII o
Cy
~~a
/p
'N
++*++
Docket No. 50-244 LS05-81-1-005 UNITEDSTATES NL7ELEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 JAN 07
",geo Mr. John Maier Vice President Rochester Gas 8 Electric Corporation 89 East Avenue Rochester, New York 14649
Dear,
Mr. Maier:
SUBJECT:
GINNA SEP TOPICS VI-8 AND II.l.C By letter dated November 24, 1980, you requested that we provide a copy of the draft evaluation of SEP Topic VI-8, "Control Room Habitability" which wo~ld document the work performed to date on the Ginna control room habitability issue.
Accordingly, we have enclosed a copy of our draft evaluation which was written subsequent to the site visits in September 1978 and March 1979.
Therefore, the draft should reflect the total effort expended on that issue.
I would like to emphasize that the material provided is a draft which'has not been reviewed and approved by the SEP.
As pointed out in our letter to you dated October 1, 1980, the topic was deleted from the SEP because of its inclusion in the TMI action plan.
Therefore, the SEP review of this issue was hal.ted prior to issuing the topic evaluation.
I would also Tike. to point out that the existence of this evaluation does not relieve you of the requirements and schedules provided for in NUREG-0737, "Clarification of TMI Action Plan Requirements."
You will note that the enclosed evaluation of Topic VI-8 recommends that you take corrective action'within the next four months (i.e.
3 to 6 months) to reduce an existing ammonia hazard and to consider further means to reduce the potential thyroid dose to reactor operators following a
- LOCA, You also requested a copy of the SEP draft evaluation of SEP Topic I'I,l,C, "Potential Hazards or Changes in Potential Hazards Due to Transportation, Institutional, Industrial'nd Military Facilities."
The. draft topic assess-ment has not been completed.
We will forward the topic assessment u'pon its completion for your review and coment in accordance
>Iith procedures developed for SEP.
Sincerely, cc w/enclosure: 'ee next page Dennis M, Crutchfield, ief Operating Reactors Brqnch. 85 Division of Licensing
l'ir: John E. Maier-R.
E.
GINNA NUCLEAR POWER PLANT DOCKET NO. 50-244 CC Harry H. Voigt, Esquire LeBoeuf, 'mb, Leiby and MacRae 1333 New Hampshire Avenue, N.
M.
Suite -1100 Mashington, D. C.
20036 Mr. Michael Slade 12 Teailwood Circle Rochester, New York 14618
.Rochester Committee for Sci ent ific Informati on Robert E. Lee,'h.D.
P. 0.
Box 5236 River Campus Station Rochester,.New York 14627
\\
Jeffrey Cohen New York State Energy Office Swan Street Buildin9 Core 1,
Second Floor Enp i re State Plaza Albany, 'New York
.12223 Director, Technical Development Programs 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 Ontari o 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 Director, Technical Assessment Division Office of Radiation Programs (AW-459)
U. S. Environmental Protection Agency Crystal Mall 02
~
Arlington, Virginia 20460 U. S. Environmental Protection Agency Region II Office ATTN:
EIS COORDINATOR 26 Federal Plaza New York, New York 10007 Herbert Grossman, Esq.,
Chairman Atomic Safety and Licensing Board'.
S. Nuclear Regulatory Coomission Washington, D.
C.
20555 Dr. Richard F. Cole Atomic Safety and Licensing Board
'U. S. Nuclear Regulatory Comnission Washington, D.
C.
20555 Dr.
Emmeth A.. Luebke Atomic Safety and Licensing Board U. S. Nuclear Regulatory Cormission Washington, D.
C.
20555 Mr. Thomas B. Cochran Natural Resources Defense Council, Inc.
1725 I Street; N. M.
Suite 600 Mashington,.D C.
20006 Ezra I. Bialik Assistant Attorney General Environmental Protection Bureau New York State Department of Law 2'orld Trade Center New York, New York 10047 Richard E. Schaffstall, Executive Director-for SEP Owners Group -
KMC 1747 Pennsylvania
- Avenue, NW Washington, D.C.
20006
R.
E. Ginna Topic YI-8 Control Room Habitability The safety objective of this review is to assure.that the plant operators can safely remain in the control room to monitor, control and maintain the plant in a safe condition after an accident.
For this purpose, we have examined the control room ventilation system and the control building structures and equipment to determine the degree of protection provided to the plant operators against the effects 'of accidental releases of toxic or radioactive gases.
Our ing normal plant operation the control'oom atmosphere will be filtered, heated and cooled as required by a ventilation system circulating 16,000 cfm of air.
Steam heating and chilled water coils are available to maintain
,temperature and humidity control, and ro'ughing type filters remove large.
particulate matter.
Fresh air makeup is permitted to the system during normal operation, the amount varying between 15 and 100 percent of the recirculation flow rate, depending on outside air temperature.
The ventilation system also includes safety grade high efficiency particulate air (HEPA) filters to remove particulate matter and 2 inch deep charcoal adsorbers to remove gaseous iodine.
These filtration components are normally bypassed.
In the event of high radiation inside the control room, the radiation monitor will signal the automatic closure of the dampers in the fresh air intake duct (and the exhaust duct) and open the damper to allow 2048 cfm of the recirculation air to flow through the HEPA filters and charcoal adsorbers.
Although not presen.ly described in the plant operating procedures, dampers can also be positioned to permit fresh air makeup to the system through the HEPA filters and charcoal adsorbers.
The radiation monitor response time and isolation damper closure time total an estimated 30 seconds.
We have calculated potential doses to the control room operators following a 'postulated LOCA according to the procedures stated in the SRP 6.4.
In evaluating the radiological doses to the operators for this control room with a volume of 21,600 ft, located 40m from the containment, we assumed no i'solation for 20 seconds and subsequent inleakage of 180 cfm (per SRP 6.4) with recirculation flow through the filters.
Based on 90/ efficient filters
,or all forms of iodine, we calculate whole-body and beta skin doses lower than 5 rem and 30 rem, respectively, in accordance with the guidelines of SRP 6.4'and Criterion 19 of the General D'esign Criterion, Appendix A to 10 CFR Part 50.
The potential inhalation dose to the thyroid, however, is calculated to be about a factor of 5 higher. than the 30 rem guideline.
These doses are based on the assumptions used in the LOCA analysis as des-cr ibed in Appendix A to the'SRP 15.6.5 and SEP Review Topic XV-19.
We have also calculated the inhalation'ose assuming that the inlet dampers are positioned after a
LOCA to allow a minimum of 200 cfm filtered air to pressurize the control room.
As already stated, these dampers are installed and available for operation, but present operating procedures do
not indicate their use after a
LOCA.
This action results in a reduction of the calculated inhalation dose to within the current criteria limit.
Me
.have discussed the post-LOCA use of these dampers with the licensee.
jwa 1',
'C ly
'L
~
~ ~wj I
Although the margin of protection to operators for recently licensed plants is requi.red to be greater, the Ginna control room habitability design provides substantial protection to the operators in the event of accidents involving radiological releases from the plant by isolation and recircula-tion.
The'design assures'that, except under rarely occurring meteorologi-cal conditions in coincidence with accidental radioactive releases that
'r
\\
W\\
are unlikely to occur even in the event of'a Design Basis Accident, the operators will not receive excessive doses.
Highly unlikely events involving sequences of postulhted successive failures more severe than
'those postulated for the design basis could potentially result in severe exposures to control room operators, however, the probability of this occurrence is so low that they are not considered in the design of nuclear power plants.
In view of the substantial level of protection provided to the control room operators and the low probability of excessive exposures to the operators, we conclude that it is not mandatory to take any immediate measures to provide additional protection to the operators.
If it is determined during the integrated safety assessment'or Ginna that the margin of safety provided for the control room operators should be improved, we, conclude that improvements can be made with minimal impact to the licensee.
QP t
~ I ~~
t
~
~
h A,
p~r~
4I h
Other areas. of review included radiation shielding, toxic gases, the occupancy of the control room and the availability of supplies for post-LOCA occupancy.
The control room is shielded with a 20-inch concrete wall on the side facing the containment, there is no door facing the containment, and no radiation streaming is expected through any penetrations between the control room and containment.
This satisfies the guidelines of the SRP 6.4 and is considered sufficient to shield control room personnel from direct radiation.
The control room is provided a kitchen with potable water and food supplies, two 300 ft air cylinders (two additional outside the control room),
and two airpacks
('four additional 'outside the control room).
We consider the control room to be capable of maintaining an emergency team (at least 5 men) for at least 5 days, satisfying the guidelines of the
, SRP 6.4.
There are'toxic chemicals stored onsite that can be postulated to pose a
hazard to the control room operator.
In particular, twelve 55-gallon drums of 30 percent liquid ammonia hydroxide're stored inside the turbine building, and one 4000-gallon tank of 0.5 percent liquid ammonia hydroxide
'is located inside the AVT Building.
In addition, one 500-gallon tank of anhydrous ammonia is stored outside next to the AVT Building.
The liquid
.ammonia hydroxide does not pose any hazard to the con'trol room operator.
The anhydrous ammonia tank is located 40m from the control room intake, and 50m upgrade.
An analysis based on Regulatory Guide 1.95 assuming instantan-
'eous catastrophic failure of the tank and release of the entire contents
is postulated to result in rapid buildup of concentrations inside the control room to over 10,000 mg/m The toxicity limit is generally considered to be 100 to 350 mg/m '.
We have also evaluated the 3(1.2}.
consequences of an accident judged more likely to occur, namely =rupture of a 2-cm pipe connected to the tank.
Uur results indicate control room concentrations of the order of 1,000 mg/m An inspection of the ammonia tank and the surrounding area has shown that the tank is in a well-protected area.
There are thick concrete I
'.wa11s on two sides of the tank, and the other two sides are protected by five 10-cm diameter solid steel-and-concrete posts spaced approximately.
4 50 cm apart, and approximately 15 cm from the tank.
Me,consider these protective features sufficient to prevent a truck or other vehicle from seriously damaging the tank.
Additionally, the intake to the control room is upwind of the tank, and around a corner of the turbine building, in a secluded alcove.
Winds from the tank to the control room intake are determined to occur approximately 5X of the time on a yearly average.
the tank does, however, include fill lines and a vent line that are not 1eak-tight.
Ihe odor of ammonia is easily detected a few centimeters away, although the odor does disperse quickly.
We consider the failure of a connecting line to the tank to be a credible event, and therefore conclude that the 500 gallon tank of anhydrous ammonia provides a significant American Conference of Governmental Industrial Hygienists, "Documentation of Ihreshhold Limit Values" Revised Edition, P.
9.
IndustriaI Hygiene and Toxicology, "Toxicology", Volume. II, Second Revised Edition, Frank A. Patty, P.
Sb2.
r
hazard to the control room operators, and we recommend that the licensee
'ake corrective action within the next few months (i.e."3 'to 6 months).
Me believe minimum of impact on the licensee would result by the installa-tion of ammonia detectors in. the control room intake or a detection devices at the tank to alarm ammonia release, and alert the operators to don self-contained breathing apparatus.
The need for additional improvements, such as closure of the control room inlet dampers on high ammonia concentration in the inlet ducts or tank failure signal, a collection system for accidentally released ammonia (water absorption or a containment around the tank), or relocation of the. tank, should be determined during the integrated safety assessment for Ginna.
I'he evaluation of this topic is complete except for the need to consider
, minimum action to reduce the ammonia hazard withinthe next 3-6 months, and the need to conside'r in the SEP integrated assessment further means to reduce tho ammonia hazard to the operators and means to reduce the potential thyroid dose to reactor operators following a LO)A.
sI Agog fggf