ML20043H782
| ML20043H782 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 06/14/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20043H781 | List: |
| References | |
| NUDOCS 9006260438 | |
| Download: ML20043H782 (3) | |
Text
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NUCLEAR REGULATORY COMMISSION p
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SAFETY EVALUATION-BY THE OFFICE'0F' NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 75 TO FACILITY OPERATING LICENSE NPF-35 AND AMENDMENT NO. 69 TO FACILITY OPERATING LICENSE NPF-52 i
l CATAWBA NUCLEAR STATION. UNITS 1 AND 2 i
DOCKET h05. 50-413 AND 50-414 j
1.0 lHTRODUCTION By letter dated' April 23,1990,, as revised and supplepented May 17 and June 4, 1990, Duke Power Company, et al., (the licensee) proposed amendments to the operating licenses for Catawba Nuclear Station, Units l'and 2, to revise surveillance requirements (SRs) with respect-to the standard used for laboratory testing of the carbon adsorber in.the filter of the Fuel Handling Ventilation Exhaust System.
Presently, for both Units 1 and 2, the carbon adsorber is periodically tested by removing a carbon sample from the filter and performing i
a laburatory analysis using the. testing criteria of Regulatory Position C.6.a i
uf Regulatory Guide 1.52. Revision 2. March 1978, for a methyl iodide penetra-tion of less than 11.
The amendments would revise SRs 4.9.11.2b.2) and 4.9.11.2c to supplenent the laboratory testing. criteria of Regulatory' Position C.6.a of l
Ret,ulatory Guide 1.52 by specifying use of " Test Hethod 'A" of ASTM D3803-86 for l
a methyl iodide penetration of less than 0.71%.
SR-4.9.11.20.4) would be
-j revised to change the heat dissipation acceptance criteria for the heaters from 80 2 8kw to 80 + 8kw/- 17.3kw.. Associated TS Bases 3/4.9.11 would be supplenented to discuss use of Test Method A of ASTM D3803-86 for Units 1 and 2.
The licensee has recently discovered that, under certain postulated low voltage l
conditions, sufficient power may not be supplied to the Fuel Handling Ventilation-Exhaust Systcm heaters to n.aintain the relative humidity of the gases entering the carbon aosorber-beds below 70% in accordance with existing SR 4.9.11.2.
In order to satisfy the Technical Specifications-(TSs), the licensee restricted the flow to 17,400 ctnias an upper limit and 14,909 cfm as a lower limit..
2.0 EVALUATION During a review of the heating, ventilation and air conditioning systems at l
Catawba Nuclear Station, the licensee discovered that the Fuel Handling Vent 11a-tion Exhaust System heaters were not conservatively sized for all. postulated -
t operating modes. During postulated low voltage conditions, sufficient power i
would not be supplied to the heaters to maintain the relative hun.idity-of the air entering the carbon adsorber beds below 70% when the flowrate is at the maximun salue, 18,222 cfm, allowed by TSs.
The licensee assessed potential
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solutions and determineo that the problem could be mitigated by) reducing its flowrate within its allowable range.(i.e., less than 17,400 cfm and limiting the fuel building temperature to less than 100*F at 100% relative humidity.
l This reduced upper limit places as unnecessarily restrictive cperating margin on the system.
The licensee stated that the proposed standard, ASTM DS803-86, " Test Method A" will require testing of carbon samples at 30 degrees-C and at 951 relative-humioity for a carbon adsorber bed decontamination efficiency of. 951. The methyl iodide penetration would be changed from 1% to 0.711.
Reducing the j
methyl iodidt penetration to 0.71% ensures a carbon adsorber decontamination
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factor of 951, that is assuined in the existing (.atewba FSAR Dose Analysis for
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the Fuel Handling Ventilation Exhaust System. The proposed inethyl iodide penetration of 0.711 instead of 1% also increases the penetration safety i'
f actor of the syt.teni f rom a f actor of 5 to 7.
The requirements of the new I
stendard compensate for the reduced capacity of the system heaters as a result of the degradeo voltage. Also, the heat dissipation value was changed i
to reflect low voltage conditions.
t For the reasons described above, this change will conservatively ensure that calculated offsite and onsite doses are not adversely affected while allowing i
the existing 18,222 cfm maximum systen, flowrate.
The NRC staff has reviewed the licensee's proposed changes. We agree with the licensee that use of Test Method A as a supplement to Regulatory Guide 1.52 pro-vides an adequate compensation for the reduced voltage to the fuel pool ventila-tion system heaters and provides reasonable assurance that the carbon efficiency-will be maintained such that pctential onsite and off site doses will not be increased relathe to the ef ficiercy and doses associated with existing TS're-quirements. Moreover, we find that the use of Test Method A as a supplement to i
Regul6 tory Guide 1.52, as proposed, meets General Cesign Criterion 42 and is l
consistent with the intent of the Standard-Technical Specifications. The proposed changes are, therefore, acceptable.
The NRC is continuing to review the guidance of Regulatory Guide 1.52 for periodic updating, including its references to appropriate industry standards such as ASTM D3803-86 and later versions of ASTM D3803. We note that, like the current TS requirements, ASTM D3803-86 Test Method A criteria do not address an equilibration period for testing samples from used carbon adsorbers. A later versicn, ASTM D3803-89, published in February 1990, addresses this subject.
Until the significance of an equilibration period during testing of used carbon samples is better understood and the staff's present review of Regulatory Guide 1.52 and associated standards is completed, we conclude that our approval of the proposed TS changes f or Catawba should be limited in duration as requested by the licensee, and should apply only until August 26, 1991, which is sufficinnt for at least one 18-n.cnth inspection of the system as required by SR 4.9.11.2.
Thereaf ter, SR 4.9.11.2 shall read the same as before our approval of the pro-posed changes.
The licensee has provided a footnote to the SR to satisfy this
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objective and the NRC staff finds the footnote acceptable.
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3.0 ENVIRONMEhTAL CONSIDERATION These annonents involve changes to the requirements with respect to the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20 and changes in surveillance requirements.
The staff has determined that the amendments involve no significant increase in the amounts, and no significant ch nge in the types, of any effluents that may be released offsite and that there is no significant increase in incividual or cumulative occupational radiation exposure.
The Comission has previously issued a proposed finding that the amenonents involve no significant hazards consideration and there has bech no public coseent on such finding. Accord-ingly, the amendments meet the eligibility criteria for categorical exclusion setforthin10CFR51.22(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 these amendments.
4.0 CONCLUSION
The Comission's proposed determination that the amendments involve no.
sionificant hazards consideration was published in the Federal Register (55.FR 18198) on May 1, 1990. The clarifications.to the Technica' 5pecificctions provioed by the licensee's subsequent letters of May 17 and June 4,1990, did not alter the initial determination of no significant hazards consideration.
The Commission consulted with the State of South Carolina.
No public coments were received, and the State of South Carolina did not have any conenents.
We have concluded, based on the considerations' discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be t
endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Comission's regulations, and the issuance of these amendunts will not be inimical to the comon defense and security or to
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the health and safety of the public.
Principal Contributors:
K. Jabbour, PDil-3/DPR-1/11 C. Nichols, SPLB/ DST l
Dated:
June 14,1990 9
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