ML20207S361
| ML20207S361 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 03/10/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20207S356 | List: |
| References | |
| TAC-60309, TAC-60310, NUDOCS 8703190312 | |
| Download: ML20207S361 (2) | |
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UNITED STATES
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E NUCLEAR REGULATORY COMMISSION n
a,E WASHINGTON, D. C. 20555
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SAFETY EVALUATION BY THE OFFICE OF NtICLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.113 TO FACILITY OPERATING LICENSE NO. DPR-32 AND AMENDMENT NO.113 TO FACILITY OPERATING LICENSE NO. DPR-3h VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION, UNIT NOS. 1 AND 2 DOCKET NOS. 50-280 AND 50-281 INTRODUCTION By a letter dated December 11, 1985, as supplemented May 13, 1986, Virginia Electric ar.d Power Company. (the licensee) requested amendments to License Nos. DPR-32 and OPR-37 for the Surry Power Station, Unit Nos. I and 2, respectively. The proposed change would revise the Technical Specifications Section 3.10 to allow the movement of the transfer canal door over the spent fuel pool, if necessary.
DISCUSSION AND EVALUATION l
The licensee requested a change to the Surry Power Station, Units 1 and 2 Technical Specifications Section 3.10 which imposes a load limit of 110% of the weight of a fuel assembly when carrying heavy loads over the spent fuel. The requested change would allow the movement of the 3600 lb transfer canal door over the spent fuel pool in the event the transfer canal door requires maintenance.
In the December 11, 1985 letter, and in a subsequent letter dated May 13, 1986, the licensee discussed the transfer canal door drop analysis and the approach being used to meet the guidelines of Standard Review Plan (SRP) Section 9.1.5, and.NUREG-0612. " Control of Heavy Loads at Nuclear Power Plants."
For heavy loads to be transported over the spent fuel pool, the guidance provided in Sections 5.1 and 5.1.1 of NUREG-0612 should be met. During the Phas3 I review of the control of heavy loads at Surry, completed in May 1984, the Surry load handling systems were evaluated against the guidelines of Section 5.1.1 of NUREG-0612. The load handling systems met the guidelines and were found acceptable.
Since no load handling system procedure changes, except as noted below, or no design changes are necessary for the requested Technical Specification change, the Phase I evaluation remains valid. However, since the transfer canal door l
8703190312 870310 PDR ADOCK 05000280 P
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. would be travelina over spent fuel, the criteria specified in Section 5.1 of NUREG-0612 need to be addressed. Only Criteria I, TI and III are applicable for this case; these criteria are:
I.
Releases of radioactive material that may result from damage to spent fuel based on calculations involving accidental dropping of a postulated heavy load produce doses that are well within 10 CFR Part 100 limits of 300 rem thyroid, 25 rem whole body (analyses should show that doses are equal to or less than 1/4 of Part 100 limits);
i II. Damage to fuel and fuel storage racks based on calculations involving accidental dropping of a postulated heavy load, does not result in a configuration of the fuel such that X,ff is larger than 0.95; and III. Damage to the reactor vessel or the spent fuel pool based on calculations of damage following accidental dropping of a postulated heavy load is l
limited so as not to result in water leakage that could uncover the fuel I
(makeup water provided to overcome leakage should be from a horated
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source of adequate concentration if the water being lost is borated).
The licensee stated in its May 13, 1986 letter that no spent fuel would be damaged if the transfer canal door was dropped onto the spent fuel pool racks.
t However, a control rod assembly could be damaged resulting in the release of radioactivity. A licensee evaluation of a fuel handling accident in the spent fuel i
pool, assuming all 204 fuel rods in a fuel assembly fail, showed that the radio-logical consecuences are below the guidelines of 10 CFR Part 100. Since a control rod does not contain fissionable material, the licensee concluded that any radioactivity released from a damaged control rod would be much less than that which could be released from a damaged fuel assembly, with radiological consecuences well within the criteria of NUREG-0612 (25% of the 10 CFR 100 limits). The staff concurs with the licensee's evaluation that there would be.
l no fuel assembly damage, and that the consequences of damaging a control rod would satisfy Criterion I of NUREG-0612, Section 5.1, and 10 CFR Part 100.
In the May 13, 1986 letter the licensee stated that for the worst case scenario of a dropped transfer canal door, only one cell in the spent fuel rack would be damaged. The resulting damage would be limited to local crushing of the top 2.42 inches of the impacted spent fuel rack cell. Dislodging the impacted cell from the rack would entail only a vertical movement of the cell, and the center-l line distance between the cells would remain unchanged in the active fuel area.
Thus, subcriticality (K@s conclusion; thus, Criterion II of NUREG-0612, less than 0.95) would be maintained. The staff i
j concurs with the licens Section 5.1 is satisfied.
The most limiting case with respect to damage to the spent fuel pool liner is a postulated drop' of the transfer canal door over a leak test channel located on the pool floor. The licensee's analysis showed that the liner plate would defom a maximum of 0.132 inches, and that the concrete surrounding the test channel would absorb the remaining impact energy. The licensee stated that the stainless steel liner would yield along the edge of the channel but would not fracture because of the high ductility of the stainless steel. Thus, there would be no leakage of water from the pool. The staff concurs with the conclusion; therefore, Criterion III of NUREG-0612 Section 5.1 is satisfied.
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, 9ased on the above evaluation, the staff concludes that movement of the transfer canal door, using the spent fuel pool load handlino system at Surry Power Station, meets the cuidelines of SRP Section 9.1.5 and NUREG-0612, and that there is reasonable assurance that movement of the transfer canal door in the manner proposed will not cause undue risk to the health and safety of the ptblic. Therefore, the requested change to the Surry Technical Specifications to allow movement o' the transfer canal door over the spent fuel pool is acceptable.
ENVIRONMENTAL CONSIDERATION These amendments involve a change in the installation or use of the facilities components located within the restricted areas as defined in 10 CFR 20. The staff has determined that these amendments involve no significant increase in the amcunts, 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 these amendments involve no significant hazards consideration and there has been no public comment on such finding. Accordingly, these 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 these amendments.
CONCLUSION 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 the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Dated: March 10, 1987 Princioal Contributors:
R. J. Giardina
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