ML20084J032
| ML20084J032 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 05/02/1984 |
| From: | Beckham J GEORGIA POWER CO. |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20084J034 | List: |
| References | |
| NED-84-220, TAC-08298, TAC-08310, TAC-48362, TAC-48363, TAC-8298, TAC-8310, NUDOCS 8405080305 | |
| Download: ML20084J032 (5) | |
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Georgia Power J. T. Beckham. Jr.
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May 2, 1984 Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz, Chief Operating Reactors Branch No. 4 Division of Licensing U. S. Nuclear Regulatory Cmmission Washington, D. C.
20555 NRC DOCKETS 50-321, 50-366 OPERATING LICENSES DPR-57, NPF-5 EIMIN I. HATCH NUCLEAR PLAMP UNI'IS 1, 2 RESPONSE '10 NRC R5EUEST FOR ADDITIONAL INFORMATION -
PROPOSED SNUBBER TECHNICAL SPECIFICATIONS Gentlemen:
By letter dated March 19,
- 1984, the NRC requested additional information concerning the proposed '1bchnical Specifications on Snubber Surveillance for Hatch Units 1 and 2 submitted by our letter dated October 27, 1983.
Included herein as Enclosure 1
is Georgia Power Conpany's (GPC) response to NRC's request for additional information.
Please be advised that GPC has taken exception to certain Standard Technical Specification criteria for snubber surveillance.
This exception is discussed in detail in Enclocure 1.
Pursuant to your request of March 19, 1984 and in accordance with the provisions of 10 CFR 50.90, as required by 10 CFR 50.59(c) (1), GPC proposes to amend Technical Specifications for snubber inservice surveillance requirements. As required by 10 CFR 50.92, J. L. Ledbetter of the Georgia Department of Natural Resources will be sent a copy of thiti submittal. The proposed charges with specific instructions for incorporation are included as Enclosures 2 and 3 for Hatch Units 1 and 2, respectively.
The proposed charges to the Technical Specifications replace those subnitted previously by our letters dated April 14, 1981, April 30, 1982, and October 27, 1983 and incorporate, where appropriate, the revisions requested by your March 19, 1984 letter.
The proposed changes to the Technical Specifications for the two Hatch units have been reviewed and approved by the Plant Review Board and the Safety Review Board and have been determined not to constitute an unreviewed safety question.
'Ite probability of ocx:urrence and the 1
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Georgia Power h Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz, Chief Operating Reactors Branch No. 4 May 2, 1984 Page 'IWo consequences of an accident or malfunction of equipment inportant to safety would not be increased above those analyzed in the FSAR because the operation of safety-related equipment is not affected by the proposed changes. The possibility of an accident or malfunction of a different type than analyzed in the ESAR would not result from those changes because no new modes of failure are introduced.
The margin of safety as defined in any Technical Specification would not be reduced by these changes because operation of the plant would remain within previously analyzed limits. The proposed changes have been evaluated and determined not to involve significant hazards considerations.
This evaluation is documented in.
As discussed in Enclosure 5, the proposed change to the Hatch Unit 1
'mchnical Specifications has been evaluated to be a single Class III amendment while that for Hatch Unit 2 has been evaluated to be a single Class I amendment. The amendment fee of $4,400.00 was subnitted previously
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by our check no. 916412 in our letter dated April 14, 1981.
Should you have any questions regarding our response to your ' request for additional information concerning snubber surveillance, contact this 1
office.
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T.
Beckham, Jr. states that he is Vice President of Georgia Power Company and is authorized to execute this oath on khalf of Georgia Power Conpany, and.that to the best of his knowledge and belief the facts set forth in this letter are true.
GEDIGIA K)WER CDMPANY By:
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J. T. Beckham, Jr.
Sworn to and subscribed before me this 2nd day of May,1984.
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Notafy Public, Georgia, State at Lagotary Public JAE/mb My Commission Expres Aug.26,1986 Enclosure xc:
H. C. Nix, Jr.
Senior Resident Inspector i
J. P. O'Reilly, (NRC-Region II)
J. L. Ledbetter i
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EPCIOSURE 1 Response to Request for Additional Information Related to Proposed Amndment to Hatch Technical Specifications 3/4.6.L (Unit 1) and 3/4.7.4 (Unit 2) - Snubbers Docket Nos. 50-321 and 50-366 1.
Proposed Technical Specification (TS) Sections 4.6.L.2 and 3/4.7.4.b -
Visual Inspection Acceptance Criteria Justify why the requirements of the last two sentences of Standard Technical Specification (Enclosure to NRC November 20, 1980 letter to all Power Reactor Licensee,
Subject:
Technical Specification Revision for Snubber Surveillance) Section 4.7.9.a (sic).
"However, when the fluid port or inoperable snubbers", are not addressed in the proposed Technical Specification.
Refponse A statement which meets the intent of Sentence 1 of the aforementioned last two sentences in Standard Technical Specification Section 4.7.9.b, "However, when the fluid port.... for the purpose of establishing the next visual inspection interval.", will be incorporated into the proposed snubber Technical Specifications for each Hatch unit.
This change is reflected in Enclosures 2 and 3.
Sentence 2 from the aforementioned last two sentences in Standard Technical Specification Section 4.7.9.b, "All snubbers connected to an inoperable comon hydraulic fluid reservior.... counted as inoperable snubbers",
is not applicable.
Neither of the Hatch units have hydraulic snubbers connected to a comon hydraulic fluid reservior.
Consequently, such a statement as shown in the Standard Technical Specifications does not need to be in the proposed snubber Technical Spacifications for Hatch.
Should comon reservoir hydraulic snubbers ever be installed at Hatch, Technical Specification changes may be proposed at such time to reflect that type of hydraulic snubber usage.
2.
Proposed TS Section 4.6.L.3 and 4.7.4.c - Pumtional Tests The following requirements need to be addressed within the TS regarding selection of the representative sample for functional testing:
a.
%e representative sample selected for functional testing shall not, to the extent practicable, include those snubbers tested in previous representative samples, and b.
At least 25% of the snubbers in the representative sample shall include snubbers from the following three categories:
1.
The first snubber away from each reactor vessel nozzle,
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C 2.
Snubbers within 5 feet of heavy equipment (valve, pung, turbine, motor, etc.), and 3.
Snubbers within 10 feet of the discharge from a safety relief valve.
Response
With regard to the representative sanple for functional testing, Section 4.7.9.c of the Standard hchnical Specifications was deviated from as shown in our October 27, 1983 sutznittal in order to eliminate biasing the sample and any possible repeated testing of the same snubber (s).
Although Item "b" above biases the " random sampling" and is contradictory to same, it does so in a conservative manner.
Consequently, the proposed snubber Technical Specifications for Hatch will be modified to incorporate the intent of the representative sample selection criteria found in Standard Technical Specifications.
This change is reflected in Enclosures 2 and 3.
3.
Proposed TS Section 4.6.L.5 and 4.7.4.e - Mechanical Snubber Functional Test Acceptance Criteria The following requirements of Standard Technical Specification 4.7.9.e need to be addressed in the proposed ".S or justify their absence a.
Requirement that drag force shall not have increased more than 50%
since the last functional test.
b.
Restraining action is achieved within the specified range of velocity or acceleration in both tension and compression.
c.
Snubber release rate, where required is within the specified rarge in canpression or tension. For snubbers specifically required not to displace under continuous load, the ability of the snubber to withstand load without displacement shall be verifled.
Response
It appears that the NRC proposed functional test acceptance criteria in Standard Technical Specifications are an effort to cover all past, present, and possibly future mechanical snubber designs.
- However, specific design features of the individual product involved as well as specialized needs at a given plant must be considered in formulating Technical Specifications. Wis was taken into account by Georgia Power Conpany in the formulation of the proposed mechanical snubber functional test acceptance criteria.
Therefore, the propose' mechanical snubber functional test acceptance criteria remain unchanged from that originally sutznitted by Georgia Power Company.
Justification
.for deviation from the NRC proposed mechanical snubber functional test acceptance criteria is discussed below by specific item.
Should mechanical snubbers be installed at Hatch that would differ in test parametets from those currently in use, Technical Specification charvjes will be considered at such time to acconinodate their specific testing parameters.
F 4
a.
With regard to drag force, the mechnical snubber vendor for those units used at Hatch has indicated that the specified maximum drag force is nominally five (5) pounds or one percent (1%) of rated snubber load, whichever is greater.
Georgia Power Company takes exception to the criteria in Standard Technical Specifications that the drag force shall not have increased more than 50% since the previous test.
Any given size snubber would serve as an
- example, a. consider a 50 kip snubber.
It's factory-rated breakaway friction can be as high as 500 lbs.
As the Standard Technical Specification criterion is worded, a given snubber could imrease by 250 lbs. and still be acceptable.
Alternatively, another 50 kip snubber may move with only 15 lbs. initially, and a 10 lb. increase would make it unacceptable since that would be an increase in excess of 50% since the last functional test.
htile that incre se is in excess of 50%, it is still less than the maximum specified drag force and is within the acceptable ranje for that snubber.
The snubber vendor for those mechanical units used at 11atch has indicated, in general, if wear is taking place in the snubber due to substantial loading, there will be a corresponding increase in friction, and it will be considerably higher than the vendor-specified "5 lbs. or 1% of rated load, whichever is greater." Consequently, it is the opinion of Georgia Power Conpany that this criterion, as worded in Standard Technical Specifications, is not warranted and GPC takes exception to it, b.
RegardinJ activation (restraining action), the acceleration of the mechanical units used at liatch is a function of the stiffness of the capstan sprinj and the weight of the inertia mass.
These do not change with time.
Because the mechanical unit functions the same in both directions requiring both tines on the capstan spring, if it restrains in one direction it will restrain in the other. ThinJs that might chanje the acceleration, such as wear or somethinJ getting inside the mechanical unit and plating out on the screw or bearing would also affect the breakaway friction i
(discussed in "a" above) and hence, the acceleration test is not necessary, c.
Because the mechanical snubbers used at flatch are not devices which " lock" when activisted, there is no " snubber release rate".
Sime all mechanical snubbers at Itatch are the same make, the
" release rate" section of the Standard Technical Specifications would not apply to either Itatch unit.
4.
Proposed TS Table Nos. 3.6-la, 3.6-lb, 3.7.4-la, and 3.7.4-lb Revise table to reflect existinj as-built conditions for Units 1 and 2.
i
Response
'Itc hydraulic and mechanical snubber tables for each flatch unit will be revised to reflect existinJ as-built coniitions.
Snubber table revisions are reflected in Enclosures 2 and 3.
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