ML18005A896
| ML18005A896 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 05/03/1989 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML18005A895 | List: |
| References | |
| NUDOCS 8905110116 | |
| Download: ML18005A896 (4) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.
10 TO FACILITY OPERATING LICENSE NO.
NPF-63 CAROLINA POWER 8
LIGHT COMPANY et al.
SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400
1.0 INTRODUCTION
By letter dated January 4, 1989, the Carolina Power 8 Light Company submitted a request for changes to the Shearon Harris Nuclear Power Plant, Unit 1 (Harris), Technical Specifications (TS), Section 3.3.3.7, "Chlorine Detection Systems," Limiting Condition for Operation (LCO) and the associated Surveillance Requirement (SR) 4.7.6.d.5.
The proposed amendment deletes TS 3.3.3.7, "Chlorine Detection Systems,"
LCO and the associated SR 4.7.6.d.5.
The requested change is based on the removal of onsite liquid chlorine in substantial quantities and the low probabilty of accidental release of chlor ine gas from transported offsite sources.
2.0 EVALUATION The Chlorine Detection Systems consist of two independent chlorine detector trains with each train consisting of a detector at each Control Room Area Ventilation System intake (both normal and emergency) and a
detector at. the chlorine storage area.
The purpose of the systems is to ensure that sufficient capability is available to promptly detect and initiate protective action in the event of an accidental chlorine release from either onsite or an offsite location.
The probability of an accidental release of chlorine is independent of whether or not a Chlorine Detection System exists; therefore, only the consequences of such an event must be considered to evaluate the justification for deletion of the system from the Technical Specifications.
The storage area detectors alarm and isolate the control room in the event of a release of chlorine at the storage area.
The licensee does not store large quantities (i.e.,quantities greater than 20 pounds) of liquid chlorine onsite at Harris.
Regulatory Guide 1.95, "Protection of Nuclear Power Plant Control Room Operators Against an Accidental Chlorine Release," specifically exempts 20 lbs or less of chlorine as small quantities for laboratory use.
Therefore, the accidental onsite release of such a small quantity of chlorine would not affect the plant operators.
As such, deletion of the storage area chlorine detectors will not increase the consequences of an accidental onsite release of chlorine.
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K pgppp~p PDC The chlorine detectors located at the Control Room Area Ventilation System intakes are intended to provide protection in the event of accidental offsite release of chlorine.
The licensee has performed a
probabi listic risk assessment (PRA) to determine the probability of accidental chlorine release in the vicinity of Harris.
The analyses calculated the probability of accidents involving the transportation of liquid chlorine on U. S.
Highway 1 and on the Seaboard Coast railroad line, the only major routes of transportation of liquid chlorine near the Harris site.
The results of the analysis show that the total probability of an accidental release of chlorine which results in toxic chlorine concentrations in the control room beingBexceeded before the operators can don breathing apparatus is 2.5 x 10 per year.
Th~ total probability reflects an accident frequency of 2.2 x 10 per year for the railroad line and 3.0 x 10 per year for trucks on U.
S.
Highway 1.
The threshold for accidents that must be considered, as stipulated by both the Nuclear Regulatory Comnission's (NRC) Regulatory Guide 1.70 and Standard Review Plan, NUREG-0800, are those accidents which have a
probability of 10 per year or greater.
Therefore, offsite chlorine release accidents have such a low probability that they are not considered to be credible events.
Based on the above arguments, the licensee reasons that deletion of the Chlorine Detection Systems from the Technical Specifications will not result in a significant.reduction in the margin of safety for the plant since both onsite and offsite accidental releases of chlorine gas which could affect plant operators are not credible events.
The NRC staff has reviewed the licensee's evaluation and analyses and finds the evaluation and analyses acceptable.
- 3. 0 ENVIRONMENTAL CONS IDERAT ION This amendment changes a requirement with respect to installation or use of a facility component located within the restricted areas as defined in 10 CFR Part 20 and changes the surveillance requirement.
The staff has determined that the amendment involves no significant increase in the
- amounts, and no significant change in the types of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure.
The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration, and there has been no public comment on such finding.
Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environ-mental assessment need be prepared in connection with the issuance of this amendment.
4.0 CONCLUSION
The Commission made a proposed determination that this amendment involves no significant hazards consideration which was published in the Federal Re ister (54 FR 7626) on February 22, 1989, and consulted with testate of Nort Carolina.
No public coments or requests for hearing were received, and the State of North Carolina did not have any coments.
The NRC staff has concluded, based on the considerations discussed
- above, that:
(I) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed
- manner, and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the cotton defense and security or to the health and safety of the pub 1 ic.
Principal Contributor:
Richard Ae Becker Dated:
May 3, 1989
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