ML20137B874
| ML20137B874 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 12/31/1985 |
| From: | Thadani A Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20137B831 | List: |
| References | |
| NUDOCS 8601160110 | |
| Download: ML20137B874 (6) | |
Text
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g 7590-01 UNITED STATES NUCLEAR REGULATORY COPMISSION BALTIMORE GAS & ELECTRIC COMPANY DOCKET NOS. 50-317 AND 50-318 ENVIRONMENTAL ASSESSMENT AND FINDING OF NO SIGNIFICANT IMPACT I
l The U. S. Nuclear Regulatory Comission (the Connission) is ,
l considering the issuance of amendments to Facility Operating Licenses I - DPR-53 and DPR-69 for Calvert Cliffs Units 1 and 2, respectively. The
- proposed amendments, submitted via applications dated December 22, 1983 and March 26, 1984, as supplemented by letters dated March 21 and August 9,1985, j would change the Technical Specifications (TS) to allow the use of a former-
! hydrogen purge line as an operational containment vent.
f, ENVIRONMENTAL ASSESSMENT Identification of Proposed Action:
At the present time, hydrogen purge motor operated valves (MOV)-6900 and 6901 are required to be maintained closed during reactor operation.
, Baltimore Gas & Electric Company has proposed changes to the TS _to allow the unrestricted opening of MOV-6900 and MOV-6901 for the purpose of pressure ,
f and airborne radioactivity control inside containment via a former hydrogen purge line*
The Need for the Proposed Action:
1 During normal plant operation, the need exists for containment purge.
i i For example, during startup, the pressure inside containment increases due i
to the heat-up of the containment at.nosphere. This pressure must be relieved to maintain margin to the 4 psi engineered safety features actuation setpoint.
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6 At the present time, the containment atmosphere is purged via the i containment sump, directly to the emergency core cooling system (ECCS) pump rooms, as needed. The ECCS pump rooms are serviced by a ventilation system which includes high efficiency particulate and charcoal filters. The issuance of the proposed amendments would allow use of the former hydrogen purge line (MOV-6900 and MOV-6901) and eliminate the need to purge via the ECCS pump room which would improve access to these areas.
Environmental Impact of the Proposed Action:
The environmental impact of allowing unrestricted use of MOV-6900 and MOV-6901 for radioactive airborne and pressure control results from consideration of the design basis accident (large break loss-of-coolant
- accident) initiated when MOV-6900 and MOV-6901 are open to the environment.
The staff has reviewed the radiological consequences of a hypothetical i
loss-of-coolant (LOCA)whileMOV-6900andMOV-6901areopen. This evaluation was conducted in accordance with the guidance of Branch Technical Position 6-4ofStandardReviewPlan(SRP)Section6.2.4,SRPSection15.6.5and Regulatory Guide 1.4.
The staff evaluation is based on the release of an estimated 569 cubic feet of containment volume prior to post-LOCA closure of MOV-6900 and MOV-6901. The staff conservatively assumed that the fraction of core fission i
product inventory available for release was 25% for iodine and 100% for the noble gases. The analysis assumed uniform mixing in the containment and used an iodine filter removal efficiency of 95% (high-efficiency particulate and charcoal filters are located downstream of MOV-6900 and MOV-6901 and prior to the environmental release point). Estimatedatmosphericdiffusion(X/Q)
- . i a
values at the Exclusion Area Boundary (EAB) and Low Population Zone (LPZ)
! Boundary consistent with a ground level release were used in the dose j calculations.
The staff estimates that the volume released through the purge line
- would result in an incremental dose increase of 42 Rem (a 38% increase) to the thyroid and 4.3 Rem (a 108% increase) to the whole body at the EAB, and
. 8.6 Rem (a 9% increase) to the thyroid and 0.9 Rem (a 30% increase) to the whole body at the LPZ, when compared to the licensing basis evaluation. The licensing basis calculation contained in the Safety EvaluationReport(SER)datedAugust 28, 1972 results in 110 Rem thyroid -
4 and 4 Rem whole body at the EAB and 80 Rem thyroid and 3.0 Rem whole body at the LPZ when no initial containment purging is assumed. It should be i
noted that the staff's dose estimates, assuming containment purging, represent an extreme upper bound because the release from the containment j 'was assumed to cont ia n fission products derived from a uniform mixing in l the containment atmosphere of the iodines and noble gases specified in TID-14844.
Even though the percentage increase in LOCA doses is not small, the actual lu total doses are a fraction of the limits of 10 CFR Part 100.. In evaluating j the impact of the increased LOCA doses, it is important to view these results in light of the low probability of the LOCA. This change does not-significantly affect the risk of any dominant accident scenario and the l
effect on overall risk of accident at this facility is insignificant.
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With regard to normal environmental releases, as indicated previously, the existing containment purge capability is via the ECCS pump room atmosphere.
The most significant change resulting from use of MOV-6900 and 6901 would be -
to provide a different purge path rather than a significant change in material released or quantitles of these materials. Moreover, the Calvert Cliffs Technical Specifications contain the NRC staff-approved Radiological Effluent Technical Specifications (RETS) for ticplementation of 10 CFR 50.36a and Appendix I to 10 CFR Part 50 regarding the limiting of radioactive material in effluents to unrestricted areas. The RETS would apply to either present or proposed containment purge path. Therefore, with regard to normal environmental releases, there will be no additional environmental impact resulting from the change in purge path.
Alternative Use of Resources:
. This action does not involve the use of resources not previously
_ considered in connection with the " Final Environmental Statement Relating to Operation of Calvert Cliffs Nuclear Power Plant Units 1 and 2" dated April 1973.
I Agencies and Persons Consulted:
The NRC staff reviewed the licensee's request and did not consult other agencies or persons.
FINDING OF NO SIGNIFICANT IMPACT The Commission has determined not to prepare an environmental impact statement for the proposed amendments.
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Based upon the foregoing environmental assessment, we conclude that the proposed action will not have a significant effect on the quality of the human environment.
For further details with respect to this action, see (1) the applications for license amendments dated December 22, 1983 and March 26, 1984 and (2) the licensee's supplemental letters dated March 21 and August 9, 1985, which are available for public inspection at the Comission's Public Document Room, 1717 H Street, N.W., Washington, D.C., and at the i
Calvert County Library, Prince Frederick, Maryland.
Dated at Bethesda, Maryland this 31st day of December,1985.
FOR THE NUCLEAR REGULATORY COMMISSION hr . f ,* -
Ashok . Thadani, Director PWR P ject Directorate #8 Division of PWR Licensing-B l
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NUCLEAR REZULATORY COMMISSION g g wAsHm0 TON, D.C. 20585
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- k p' December 31, 1985 DOCKET No. 50-317/318 MEMORANDUM FOR: Ql$4)(48)t)ti)$N)(M4)$)St)lm Rules and Records Branch JQtAMW)RHt)tMMM)0m)tHM Division of Rules & Records Office of Administration FROM: Office of Nuclear Reactor Regulation 19488 - Room 4000 Division of Licensing
SUBJECT:
CALVERT CLIFFS l'i4ITS 1 & 2 One signed original of the Feders/ Register Notice identified below is enclosed for your transmittal to the Office of the Federal Register for publication. Additional conformed copies ( 6 ) of the Notice are enclosed for your use.
. Notice of Receipt of Application for Construction Permit (s) and Operating License (s).
Notice of Receipt of Partial Application for Construction Permit (s) and Facility License (s): Time for Submission of Views
~
on Antitrust Matters.
O Notice of Consideration of issuance of Amendment to Facility Operating License.
Notice of Receipt of Application for Facility License (s); Notice of Availability of Applicant's Environmental Report;and Notice of Consideration of issuance of Facility License (s) and Notice of Opportunity for Hearing.
Notice of Availability of NRC Draft / Final Environmental Statement.
Notice of Limited Work Authorization.
e Notice of Availability of Safety Evaluation Report.
Notice of issuance of Construction Permit (s).
Notice of lasuance of Facility Operating License (s) or Amendment (s).
Order.
Exemption.
" Notice of Granting of Relief, h Other: Notice of Environmental Assessrnent and Finding nf Nn Kignificant fmnact Office of Nuclear Reactor Regulation Division of Licensing, ORB #3
Enclosure:
As stated cc w/ enclosure:
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