ML20244B508
| ML20244B508 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 04/10/1989 |
| From: | Morgan H COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20244B510 | List: |
| References | |
| 5603K-7, NUDOCS 8904190241 | |
| Download: ML20244B508 (4) | |
Text
_ - _ _ - - _ _ --
-q
,1
-, [-
N Comm:n :: ith Edison t
4 / 72 West Adams Street Chicano. Illinois
/ Address RIply to: Post Office Box 767
\\
V V Chicago, Illinois 60690 - 0767 April 10, 1989 U.S. Nuclear Regulatory Commission ATTN Document Control Desk Washington, DC 20555
Subject:
Dresden Nuclear Power Station Unit 1 Emergency Plan Response to Request for Additional Information NRC Docket No.50-010 References (a):
P.B. Erickson letter to W.E. Morgan dated January 7, 1989.
(b):
W.E. Morgan letter to US NRC dated March 27,-1989.
Dear Sirs Reference (a) requested additional information concerning the accident analysis and protective action plans regarding Dresden Unit 1.
Reference (b) stated that this information would be provided by April 10, 1989. The following attachment provides the requested additional information.
Additionally, an attachment that was to be provided in Reference (b) concerning Dresden Unit 1 Decommissioning Plan, Question 2, Nuclide Concentration, was inadvertently left out.
This information is also being submitted (Attachment 2).
If you have any questions regarding this matter, please contact this office.
l Very truly yours, j
,a L M W.
Morgan Nuclear Licensing Administrator im
. Attachments cc:
P.B. Erickson - NRR l
j NRC Resident Inspector - Dresden 8904190241 890410 PDR ADOCK 05000010 F
5603k/7 PDC
.m
C0091ENT #1 f.
What ere tha worst'ctsa skin dosas projectsd onsite, in creas that would i
l-be occupied, and at the sito boundary for a fuel rod rupture accident at L
Dresden 17 j
RESPONSE #1 The worst case skin dose projected onsite in areas that would be occupied is 1085 rads / hour in the Unit 1 Fuel Building. This dose rate was calculated assuming that a fuel handling accident in the fuel building-resulted in damage to the fuel cladding of 100% of all pins in all 683 I
l-
. fuel assemblies.
The worst case skin dose projected at the site boundary for a fuel rod rupture accident at Dresden 1.is 1.7 Rad within two hours. This dose I
rate was calculated assuring that a fuel handling accident in the fuel-building resulted-in damage to the fuel cladding of 100% of all. pins in all 683 fuel assemblies.
Further details of the assumptions and calculational method used may be found in the attached report:
" Determination of the Potential Radiological Consequences from a Fuel Handling Accident at the Dresden Nuclear Pcwer Station Unit 1".
It should be noted that this document reports some of the skin doses in Rem as opposed to Rads. The substitution of one for the other is acceptable due to the beta dose from Krypton-85 having a Quality factor of one (1).
Rem = Rad
- Quality factor.
COMMENT #2 What protective actions would be implemented onsite and offsite in the event of a worst case fuel rod rupture accident at Dresden 17 RESPONSE #2 The study " Determination of the Potential Radiological Co'nsequences from a Fuel Handling Accident at the Dresden Nuclear Power Station Unit 1" provides projections of worst case skin and whole body radiation doses to personnel onsite and at the site boundary due to a spent fuel rupture accident of all 683 fuel assemblies in the Fuel Building pool with subsequent environmental release. Onsite protective actions from this worst case event would be initiated upon receipt of the Fuel Building area radiation monitor (ARM) alarm, This ARM will alarm locally in the building and also in the control room. Precedures require the evacuation of the Fuel Building, upon receipt of the local alarm, as well as the initiation of the Emergency Action Level condition concerning a Unit i fuel handling accident. Thus, the receipt of this alarm would bring the I
stations emergency response plan into action.
Protective actions would include an assembly of all onsite personnel in predesignated assembly Radiation Protection Technicians would be dispatched to the l
areas.
assembly areas to assess the radiological conditions in these areas.
During the assembly, all personnel would be accounted for and information
(
about the nature of the accident would be distributed. Additional J
Radiation Protection Technicians would be dispatched to perform radiation l
surveys around the Fuci Building and to set up barriers to prevent l
inadvertent access. Access to the affected areas would be limited until i
the results of radiation surveys indicated acceptable radiological l
l conditions.
l 3372a l
l I
Th2 otudy "Detarminstion of tha Potcntiel Radiological Consequ;necs from a Fual HLndling Accid:nt at ths Drssdsn Nucicer Powar Station Unit 1" shows that the maximum offsite whole body dose from an accidental release of Krypton-85 to be about 0.016 Rem within two hours, and the corresponding skin dose to be about 1.7 Rad within two hours. These doses calculated at the site boundary from an accidental release of Krypton-85 are significantly less than the 10 CFR 100 whole body dose limit of 25 Rem in two hours, and the corresponding skin dose equivalent limit of 150 Rad in two hours. They are also significantly less than the U.S. EPA Protective Action Guide (PAG) limit of 1 Rem whole body.
EPA guidance indicates that no planned protective actions are recommended if the PAG is not exceeded. Since the calculated maximum whole body dose at the site boundary is less than the 1 Rem PAG and also less than the 10 CFR 20 limit of 500 mrem, no offsite protective actions would be anticipated from a worst case fuel rod rupture accident at Dresden Unit 1.
COMMENT #3 In the event of an emergency at Dresden 1, what licensee staff augmentation would be implemented?
RESPONSE #3 During emergency conditions, the Dresden staff would be augmented in accordance with our Emergency Plan Implementing Procedures (EPIP). The EPIPs have several event classifications that could apply.
These are as follows:
(1)
The Unusual Event classification: no additional staffing is required. However, notifications are made and station supervision has the authority to call in additional support personnel as needed.
(2)
The Alert classification:
the Technical Support Center (TSC) and the Operational Support Center (OSC) are required to be manned within sixty minutes utilizing on site personnel.or off site personnel notified by a call tree. Manning of these emergency facilities requires a minimum of an additional seven personnel.
Depending on the type of emergency, however, this minimum manning would be supplemented as deemed necessary.
(3,4) The Site Emergency and General Emergencv classifications:
the TSC and the obc would also be manned. At these higher emergency classifications, minimum manning increases to thirty eight additional personnel. Also at these higher classifications, the Emergency Operations Facility (EOF) ir. activated and manned.
Minimum manning of this facility requires six personnel.
3372a 1
m
' ' COMMENT #4 What are the Emergency Action Levels (EAL) for.a fuel handling accident at Dresden 17 RESPONSE #4 There are two Emergency Action Levels (EAL) for a fuel handling accident L
on Dresden Unit 1.
The first is at the. Alert level and states " Radiation levels on the' Unit 1 Fuel Building ARM, except during controlled, planned-evolutions, are greater than 60mR/hr and Unit 1 Gaseous Monitoring Vent system'is operational". The second is at the Site Emergency level and-states " Radiation levels on the Unit 1 Fuel Building ARM, except during controlled, planned evolutions, are greater than 60mR/hr and Unit 1 Gaseous Monitoring Vent System is not operational".
COMMENT #5 What are the Emergency Action Levels for a noble gas release at Dresden 17 RESPONSE #5 There is no specific EAL for a noble gas release from Dresden Unit 1; The study " Determination of the Potential Radiological Consequences from a Fuel Handling Accident at the Dresden Nuclear Power Station Unit 1" indicates that even during the worst case fuel handling accident _that released all the Krypton-85 from all the fuel stored in the pool, there would be no need to take offsite protective actions. However, station emergency actions would be activated by the EAL dealing with fuel handling-accidents as noted in Response #4.
3372a
__;