ML17159A171
| ML17159A171 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 02/19/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML17159A169 | List: |
| References | |
| NUDOCS 9803090340 | |
| Download: ML17159A171 (3) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555<001 SAFETY VALUATION BY HE OF ICE 0 NUCLEAR REACTOR REGULATION RELA ED 0
AMENDM NT 0.172 0
F CILITY OPERATING L CENSE NO. NPF-14 MENDMENT NO, 145 TO FACILITY OPERATING LICENSE NO. NPF-22 ENNSYLV N PO ER
& LIGHT COMPANY ALLEGHENY LECT IC COOPERATIVE C.
SUS UEHANNA STEAM ELECTRIC STATION UNITS 1
AND 2 DOCKET NOS. 50-387 AND 388
- 1. 0 INTRODUCTION By letter dated May 31, 1996, the Pennsylvania Power and Light Company (PP&L, the licensee) submitted a request for changes to the Susquehanna Steam Electric Station (SSES),
Units 1 and 2, Technical Specifications (TSs).
The requested changes would delete, from the TSs, Section 4.7.2.d.2, the surveillance requirement for chlorine detection for the control room emergency outside air supply system as a result of the removal of bulk quantities of gaseous chlorine from the Susquehanna Steam Electric Station.
2.0 BACKGROUND
In accordance with Regulatory Guide (RG) 1.95, "Protection of Nuclear Power Plant Control Room Operators Against an Accidental Chlorine Release,"
(January 1977)
PP&L has installed in the fresh air intake of the control structure.HVAC (heating, ventilation, and air conditioning) systems, a chlorine detection system which upon detection of chlorine gas in the incoming air stream will initiate automatically the isolation of the control room air flow, close
- dampers, and shut off fans.
This RG was intended to protect reactor operators from the hazards of an on-site chlorine release.
In the past, bulk quantities of gaseous chlorine were used and stored at SSES to control the growth of micro-organisms in the open cooling water systems, circulating water and service water to prevent bio-fouling of heat exchangers and the cooling tower.
- Recently, PP&L has replaced the chlorine with a non-oxidizing biocide and has removed the bulk quantities of the chlorine gas from the site.
In a submittal dated October 28,
- 1994, PP&L had requested the deletion of a number of other surveillance sections from the TSs related to chlorine detection which was evaluated by the staff and approved in a safety evaluation with Amendments 147 and 117, dated June 19, 1995.
This particular TSs section was inadvertently omitted from the 1994 request.
9803090340 980219
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3.0 ALUA 0
The licensee indicated in its submittal that the removal of chlorine from the site eliminates the potential for.an on-site toxic gas release and thus relieves the licensee from following the guidelines in RG 1.95 and specifically the need to have the chlorine detection system in the control room HVAC system.
PPKL indicated in discussions with the staff that it has replaced the chlorine with the product Betz Clam-Trol CT-I as its biocide.
This product is a combination of organic compounds which control the growth of micro-organisms in water systems.
It is non-oxidizing and is relatively nontoxic to humans.
The biocide is added to the water systems in liquid form with the following two active ingredients suspended in an alcohol mixture:
alkyl dimethyl benzyl ammonium chloride, and dodecyl guanidine hydrochloride.
Since there is chlorine in compound form in the biocide, the staff concludes that any potential spills of the biocide will not,result in the release of chlorine gas to the environment and especially to the control room.
The licensee indicated that it has used a methodology based on the analysis included in the SSES Final Safety Analysis Report in Section 2.2.
- Further, a
bounding calculation was used as well as the frequency guidelines included in RG 1.78, "Assumptions for Evaluating the Habitability of a Nuclear Power Plant Control Room During a Postulated Hazardous Chemical Release."
In its submittal, PPEL discussed the hazards of an off-site chlorine release.
In a study to investigate the risk of a hazardous off-site chlorine
- release, the risk frequency of such a release is shown to be less than the Standard Review Plan lower radioactivity release frequency limit of lE-7/year.
Our study concluded that the current chlorine shipping frequency is less than the minimum considered significant in Reg.
Guide 1.78, "Assumptions for Evaluating the Habitability of a Nuclear Power Plant Control Room During a Postulated Hazardous Chemical Release",
- June, 1974.
Thus, off-site chlorine release is judged to be insignificant for radiological impact on the safety and health of the public.
- Further, because of the amount of chlorine released, any "puff" is expected to pass the station in minutes..
Self-contained breathing apparatus and manual control room isolation are available to mitigate the on-site consequences of off-site chlorine release.
Specifically, the bounding calculation resulted in a calculated release risk of less than 4.7E-9 core damage/yr from chlorine release off-site.
The staff finds that the methodology was acceptable and the result of the calculation to indicate that the effect of removal of the chlorine detection system would be acceptable.
In addition, the staff agrees with the licensee's conclusion based on RG 1.78 that the infrequent shipping of chlorine past the SSES site need not be considered in the evaluations of control room habitability.
Based on the above. discussion, the staff finds that deleting the surveillance and action statements from the TSs relative to the operability of the chlorine detection system does not affect the integrity, function, or performance of
any safety related
- system, function, or equipment in the SSES units.
Even in the event of an off-site release of chlorine, adequate measures are available for the operators to mitigate any potential hazards to those in the control room through manual HVAC system isolation and the use of a self-contained breathing apparatus.
Thus, this TS change does not affect the level of protection provided to the reactor operators and margin of safety at the units will remain unchanged.
Therefore, the staff concludes that the removal of the bulk quantities of chlorine from the site and the use of the alternate biocide makes RG 1.95 inapplicable to SSES, and finds the TS change to be acceptable.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Pennsylvania State official was notified of the proposed issuance of the amendments.
The State official had no comments.
- 5. 0 NVIRONMENTAL CONSIDERATION The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and change surveillance requirements.
The NRC staff has determined that the amendments involve 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 the amendments involve no significant hazards consideration, and there has been no public comment on such finding (62 FR 38137).
Accordingly, the amendments meet 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 environmental assessment need be prepared in connection with the issuance of the amendments.
- 6. 0 CONCLUSION The Commission 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, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
C. Poslusny Date:
February 19, 1998