ML20214E302
| ML20214E302 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 05/12/1987 |
| From: | Carey J DUQUESNE LIGHT CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8705220029 | |
| Download: ML20214E302 (5) | |
Text
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'Af Telephone (412) 393-6000 x4 SNppmgport, PA 15077-0004 May 12, 1987 U. S. Nuclear Regulatory Commission Attn:
Document Control Desk Washington, DC 20555
Reference:
Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Technical Specification change Request No. 126, Rev. 2, Confirmatory Items Gentlemen:
.In our submittal of April 16, 1987 we provided the above referenced change request.
- Therein, we stated that it would be necessary to provide follow-up documentation confirming that radiation doses to the control room operators would meet acceptance criteria and that they would be adequately protected from a chlorine gas release.
In order to demonstrate the control room operators are protected in accordance with 10 CFR 50, Appendix A, GDC-19, a complete set of new Beaver Valley Unit 1
analyses were performed in order to be consistent with the analyses completed for Beaver Valley, Unit 2.
The results of these analyses demonstrate that with the implementation of the identified modifications, the control room operators will be protected in accordance with GDC-19 and that there are no significant differences in the radiological consequences of the BVPS-1 and BVPS-2 accidents.
Additionally, we compared the control room operators doses, both l
before and after the control room emergency ventilation system l
modifications, to demonstrate there was no significant increase in hazard to the operators.
The results are tabulated on Table 1 which show an actual decrease in dose to the thyroid as a result of these i
modifications.
The overall dose is demonstrated as being reduced to the control room operators.
This reduction in dose is a result of two independent factors; 1) the control room volume is increased L
which results in a more diluted concentration in the control room and 2) the increased air make up rate results in an increased purge rate of the control room with filtered air.
The major contributor to the operators dose is the assumption that there is 10 cfm unfiltered in-leakage to the control room in accordance with SRP guidelines.
At one hour after the accident, the containment is returned to subatmospheric conditions and the only remaining release is that from ECCS leakage which is filtered prior 8705220029 870512 g/
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"'LBenv3r? Valley Powex"Staticn,: Unit No.'1 Docket No.u50-334,~ License No. DPR-66
- Technical Specification Change Request-No. 126, Rev. 2,
. Confirmatory Items Page 2 to release-from-the plant areas.
From this time on,'the. source in the - control zxxxn is _ diluted as the emergency ventilation system purges this. air -from the control room envelope.
outleakage is'via normal' control room leakage paths.
The-increased air flow rate-increases the rate of purge and results in a: lower. dose to the operators.-
In.
order to further
-illustrate this'
- point, additional calculations were performed.
Table 2 provides calculation results which _ demonstrate that as the flow increases the dose decreases.
The-calculations are for-the ~ combined control room with all parameters remaining. the usame except for the make-up air flow rate-(emergency ~
ventilation intake rate).
You should-note that the doses on Table =21 are -higher-than on Table 1
for the 690'cfm make-up air flow rate (minimum required flow to maintain: the combined control room at a pressure of 1/8 inch water gauge above atmospheric) to the combined control room.
The reason for this is'an' assumed efficiency of 90% on the main filter
- banks, Supplemental Leak Collection and Release System (SLCRS),
versus a
95%
efficiency for the SLCRS on. Table-1.
Since Table 2 is being provided to demonstrate dose decreases as flow increases, the 90% SLCRS efficiency.is not a significant issue.
Our-
~
analyses of
- record, Table 1,
assumes a 95% collection efficiency, Table 2
is for illustration only.
Furthermore, it is worth noting that at an. assumed 90%
SLCRS collection efficiency we are still capable of: demonstrating compliance to GDC-19.
The second item requiring confirmation addressed the ability to protect the operators from a chlorine release accident.
At the time of our' April 16, 1987 submittal, we were conducting analyses to demonstrate our installed chlorine detectors' would provide the required protection.
Since that time we have determined the system response was inadequate and we are in the process of replacing it with~ a system similar to that which has been installed in Unit 2.
The details lof the problems associated with these detectors will be discussed in further detail in separate correspondence submitted in accordance with 10 CFR 50.73.
We are obtaining vendor data and conducting additional investigations into the expected operating characteristics of the new chlorine detectors.
A new analysis has not been completed at this time.
We do commit, however, to providing chlorine protection such that the toxicity limits are not exceeded in the control room in the first two minutes after the operators are made aware of the presence of chlorine.
This is consistent with Regulatory Guide 1.95, Section B and our stated position in the no significant hazards consideration for Technical Specification change Request No. 126, Rev. 2.
We will be operating in accordance with our
' Technical Specification on chlorine detectors, and the related NRC
- SER,
'in the interim until this modification is completed.
There are no changes to our Technical Specifications required as a result of our upgrading our chlorine detectors.
i
c;.
. Beaver Valley (Power Station, Unit No. 1
=
. Docket No.'50-334,! License No.- DPR-66 LTechnical-Specification Change: Request'No. 126, Rev. 2,
. Confirmatory Items
~Page 3' If your have any' questions regarding'this submittal, please call me or members of my. staff.
Very truly yours,
. J. Carey Senior Vice' President, Nuclear cc: Mr. S. M. Pindale, Resident Inspector U.,S.
Nuclear. Regulatory Commission-Beaver Valley Power Station Shippingport, PA 15077 U. S. Nuclear Regulatory Commission Regional Administrator Region 1 631 Park Avenue King of Prussia, PA 19406 Mr. Peter S. Tam U. S. Nuclear Regulatory Commission Project Directorate No. 2 Division of PWR Licensing - A Washington, DC 20555
- Mail Stop 316 JAddressee only Director, Safety Evaluation & Control Virginia Electric & Power Company P.O. Box 26666-One James River Plaza Richmond, VA 23261 Mr. Thomas M. Gerusky, Director Bureau of Radiation Protection Pennsylvania Dept. of Environmental Resources P.O. Box 2063 Harrisburg, PA 17120
7 TABLE-1 1
BV-1 LOCA - Control Room Doses' (includes ECCS Leakage Summary)
(30-Day Integrated Doses)
Before Modifications (1)'
After Modifications (2)
' Doses (Rem)
Thyroid 25 17 Gamma
'O.23
< 0.3
-Beta 2.1
<.2.5 (1)
Ref:
Calc. 14110.39-UR(A)-457-0; assumes a 360 cfm air make-up flow rate to the Unit 1 control room volume.
(2)
Ref:
Calc. 14110.39-UR(B)-450-1;' assumes a 690 cfm air make-up flow rate to the combined control room volume.
TABL3~2 (1)
'BV LOCA
~ Cont'rol Room Doses Versus Emergency Ventilation Intake Rate 30-Day Integrated Intake Rate Dose (Rem) 690 cfm 1000 cfm Thyroid 26 23 Gamma
< 0.3
< 0.3 Beta
< 2.5
< 2.5
'(1)'
Ref:
Calc. 14110.39-UR(B)-450-1 (TABLE 3-E)
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