ML20135H876

Safety Evaluation Supporting Amend 4 to License NPF-29

ML20135H876
Person / Time
Site:	Grand Gulf
Issue date:	09/18/1985
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20135H873	List: ML20135H872 ML20135H876
References
TAC-59184, TAC-59185, TAC-59186, TAC-59187, NUDOCS 8509240337
Download: ML20135H876 (5)

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.4 TO FACILITY OPERATING LICENSE NPF-29 GRAND GULF NUCLEAR STATION, UNIT 1 MISSISSIPPI POWER & LIGHT COMPANY n

MIDDLE SOUTH ENERGY, INC.

SOUTH MISSISSIPPI ELECTRIC POWER ASSOCIATION INTRODUCTION By letter dated July 3, 1985, the licensee (MPal) proposed to change the facility Technical Specifications to be consistent with equipment modifications planned to be made during a scheduled outage in October and November 1985 and to add a license condition to temporarily make the railroad bay area a part of secondary containment in order to facilitate movement of high density spent fuel racks into the auxiliary building.

By letter dated August 12, 1985, licensee revised the proposed license condition to explicitly limit to one hour the time the railroad bay door could remain ope'n for the purpose of moving a truck into or out of the bay area instead of the four-hour limitation which could be implied by the July 3 proposal. The staff's evaluation of these proposed changes is presented herein.

EVALUATION The amendment would make five changes in the Technical Specifications: (1) add four smoke detectors in Table 3.3.7.9-1, " Fire Detection Instrumentation;"

(2) add a circuit breaker in Table 3.8.4.1-1 " Primary Containment Penetration Conductor Overcurrent Protective Devices;" (3) replace three smoke detectors with three flame detectors in Table 3.3.7.9-1 " Fire Detection Instrumentation;"

(4) change the local leak rate test method from pneumatic to hydrostatic for test return lines in the residual heat removal (RHR) loop "C" and the low pressure core spray system by adding footnotes for applicable valves in Table 3.6.4-1,.

" Containment and Drywell Isolation Valves;" and, (5) provide a temporary exception to the boundary integrity requirements in Technical Specification 3/4.6.6

" Secondary Containment" to facilitate installation of high density spent fuel racks in the auxiliary building.

The staff has reviewed these five proposed changes.

Two of the proposed changes in Technical Specifications (changes (1) and (2)) are needed because of design changes being made to enhance safety of operation.

The design change for Tech-nical Specification change (1) would a'dd fire detection instrumentation in an area containing safety related electrical cables where there are now no detectors.

The design change for Technical Specification change (2) would add an overcurrent protection circuit breaker in a new 480 volt power circuit running from the horizontal fuel transfer system (HFTS) main console outside containment to a revised design HFTS inside containment.

The revised design HFTS uses hydraulic C509240337 850918 PDR ADOCK 05000416 P

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j servo mechanisms to upend fuel assemblies instead of the current design HFTS which uses mechanical mechanisms. The new mechanisms will enhance safe handling of fuel assemblies by increasing the stability and reliability of the upending assembly. The new equipment is designed and will be installed in accordance with i

applicableregulatory) requirements,industrycodesandstandards,theGrandGulf NuclearStation(GGNS Quality Assurance Program and the GGNS Final Safety Analysis Report (FSAR). Therefore, the designs are included in the current licensing bases and are bounded by existing safety analyses in the FSAR.

Based on its review of licensee's-July 3,1985, submittal as summarized herein, staff concludes that the proposed additions to Technical Specification Tables 3.3.7.9-1 and 3.8.4.1-1 (changes (1) and (2)) will enhance safe operation and are acceptable.

Technical Specification change (3) is proposed because of a design change being made to substitute flame detectors for smoke detectors in the corridor between the diesel generator building and the auxiliary building.

Plant operation has j

demonstrated that diesel generator exhaust fumes get into the corridor causing false alanns on the smoke detectors.

Flame detectors are adequate to detect a fire, and they will lessen the frequency of false fire alarms. The design change will be performed in accordance with applicable regulatory requirements, industry code's and standards, the GGNS Quality Assurance Program and the GGNS FSAR. The design change is consistent with the licensing basis and safety -analyses.

Based on its review of the licensee's July 3,1985, submittal as sumarized herein, the staff concludes that replacing the smoke detectors with flame detectors in l

Table 3.3.7.9-1 is acceptable.

In change (4) of the MP&L submittal, eight isolation valves within the residual i

heat removal (RHR) C and low pressure core spray (LPCS) return lines to the suppression pool would be hydrostatically leak tested as opposed to the current l

pneumatic leak testing. This change is based on design changes to the lines which will extend the lines to ensure that they exit below the minimum suppres-j sion pool water level. The affected isolation valves would not be exposed to the i

post-accident containment atmosphere conditions because of the suppression pool, i.e., the presence.of water seal. Therefore, the staff finds hydrostatic leak testing of the eight (LPCS and RHR C return lines) isolation valves is justifi-

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l able once the design changes are implemented.

Therefore, the proposed Grand Gulf 3

Technical Specifications change request is acceptable.

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Change.(5) of the MP&L submittal proposes to amend the subject license to tempo-rarily allow the railroad bay area including the exterior railroad bay door on the auxiliary building to be classified as a secondary containment isolation j

boundary. This modification would be subject to the same actions and requirements 1

as other secondary containment isolation boundaries. The proposed amendment which j

is in the form of a license condition is to last during the moving of new high density spent fuel storage racks and other associated equipment into the auxiliary building, but will not exceed 144 cumulative hours. This activity is I

to be performed within approximately a one-month period while the plant is in operation. Currently, the present design configuration of the auxiliary building railroad bay area does not totally qualify as part of the secondary containment.

j This area is isolated from secondary containment by inner railroad bay doors and l

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overhead equipment hatch plugs.

In order to move the new spent fuel racks and other equipment to the fuel handling area of the auxiliary building, the exterior railroad bay door must be opened and reclosed when a truck is placed in the rail-road bay. The proposed license condition in the August 12, 1985, submittal i

requires that the railroad bay door not remain open longer than one hour when moving a truck into or out of the railroad bay. The equipment hatch plugs must be removed which causes a loss of secondary containment integrity as defined in the Technical Specifications. MP&l. does not intend to reinstall the equipment hatch plugs each time a truckload of fuel racks or other equipment is moved into or out of the railroad bay area.

Instead, MP&f. proposes to use the exterior 4

j railroad bay door as. a secondary containment isolation barrier during the i

estimated upper limit of 144 hours0.00167 days <br />0.04 hours <br />2.380952e-4 weeks <br />5.4792e-5 months <br /> required to complete the task. While the railroad bay does not meet the secondary containment design requirements for tornados, fires and earthquakes, it does provide an acceptable leakage barrier.

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MPal. intends to demonstrate its functional operability by meeting the surveillance j

requirements specified in Technical Specification 4.6.6.1.b. i.e., opening the a

inner door and drawing the secondary containment to establish the negative f

pressure at the start of the license condition.

For the proposed license con-i dition period, the exterior railroad bay door will be controlled in accordance with the requirements of TS 3/4.6.6.1, such that if the bay door fails for any i

reason the plant will be placed in a condition where secondary containment j

integrity is not required.

j The staff has reviewed postulated accidents while using the railroad bay as j

secondary containment and concludes that the proposed license amendment does not i

affect any conclusion or computed dose reported in staff's Safety Evaluation i

i Report for the Grand Gulf Nuclear Station. Under the proposed amendment, the

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railroad bay would be used as secondary containment for a cumulative time of 144

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hours and the new containment boundary would be required to pass the surveillance I

test of Technical Specification 4.6.6.1.b at the beginning of this period. While this temporary secondary containment boundary would be more susceptible to damage j

by tornado or earthquake, its ability to mitigate all design basis accidents i

would be equivalent to the normal boundary.

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Additionally, administrative controls will be implemented during the proposed i.

license condition period to ensure periodic monitoring of meteorological con-ditions so that appropriate precautions may be taken to fulfill the design i

requiretrents for tornado depressurization. A fire watch will also be established j

in the railroad bay during its use as secondary containment.

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i Based on its review o'f licensee's July 3 and August 12 submittals as summarized I

herein, and the low probability of an earthquake and an accident occurring during the short duration period the railroad bay would be used as secondary cont.ainment, the staff finds the proposed license condition in the August 12, 1985, submittal

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to be acceptable.

ENVIRONMENTAL. CONSIDERATION l

The amendment involves changes of requirements of facility components located within the restricted area as defined in 10 CFR.20.

The Commission made a l

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l proposed determination that the amendment involves no significant hazards con-sideration acd there have been no comments on that proposal.

Based on its evaluation, tt.e staff concludes that there is no significant change in types or significant increase in the amounts of any effluents that may be released 1

offsite. There is no significant increase in individual.or cumulative occupa-j tional radiation exposure because the fuel racks to be handled have not been used to store irradiated fuel. Accordingly, the 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 environmental assessment i

need be prepared in connection with the issuance of the amendment.

CONCLUSION The C'mmission made a proposed determination that the amendment involves no o

significant hazards consideration which was published in the Federal Register (50 FR 32796) on August 14, 1985, and consulted with the state of Mississippi.

No public comments were received, and the state of Mississippi did not have any comments.

.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 endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations, and issuance of this amendment will not be inimical to the common defense and security or, to the i

j health and safety of the public.

j Principal Contributors:

Om P. Chopra, Power Systems Branch, DSI A. Notafrancesco, Containment Systems Branch, DSI i

J. Read, Accident Evaluation Branch, DSI D. Kubicki, Chemical Engineering Branch, DE 2

lester L. Kintner, licensing Branch No. 4, DL 1

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Dated: September 18, 1985 1

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S:ptembcr 18, 1985 AMENDMENT NO. 4 TO FACILITY OPERATING LICENSE N0. NPF Grand Gulf, Unit 1 DISTRIBUTION:

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RDc::ket No. 50-416 NRC POR local PDR NSIC PRC System LB #4 r/f E. Adensam L. Kintner M. Duncan Attorney, OELD R. Diggs, ADM T. Barnhart (4)

E. L. Jordan, DEQA:I&E

l. Hannon, I&E B. Grimes J. Partlow M. Virgilio

0. Chopra, PSB A. Notafrancesco, CSB J. Read, AEB D. Kubicki, CHEB D=1cng:m gyg7,,.

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