At all nuclear plants, overhead cranes are used to lift heavy objects in the vicinity of spent fuel. If a heavy object such as a spent fuel shipping cask or shielding block were to fall onto spent fuel in the storage pool or reactor core during refueling and damage the fuel, there could be a release of radioactivity to the environment. Such an occurrence also has the potential for overexposing plant personnel to radiation. If the dropped object were large and the damaged fuel contained a considerable amount of undecayed fission products, radiation releases to the environment could exceed 10 CFR Part 100 guidelines. With the advent of increased and longer-term storage of spent fuel, the NRC determined that there was a need for a systematic review of requirements, facility designs, and TS regarding the movement of heavy loads to assess safety margins and improve them where necessary.
This item was originally identified in NUREG-0371[1] and was later determined to be a USI in NUREG-0510.[2]
This USI was RESOLVED in December 1980 with the issuance of GL 80-113,[3] following publication of the report on the NRC review of nuclear power plant load-handling operations in NUREG-0612.[4] GL 80-113[5]
requested licensees to review their controls for the handling of heavy loads to determine the extent to which guidelines in NUREG-0612[6] were being satisfied, and to identify the changes and modifications that would be required in order to fully satisfy the guidelines. GL 81-07[7] was subsequently issued to correct errors in GL 80-113.[8]
Licensee responses to NUREG-0612[9] were requested in two parts: Phase I (6-month response); and Phase II (9-month response). For operating plants, MPAs C-10 and C-15 were established by NRR/DL to track the implementation of Phases I and II, respectively.[10] For future plants, SRP[11] Section 9.1.5. was revised. At the completion of Phase II, the results of the NRC findings were published in GL 85-11.[12] However, in April 1999, Issue 186 was identified to address the NRR concern that licensees operating within the GL 85-11[13] regulatory guidelines were not taking adequate measures to assess and mitigate the consequences of dropped heavy loads.
[1] NUREG-0371, "Task Action Plans for Generic Activities (Category A)," U.S. Nuclear Regulatory Commission, November 1978.
[2] NUREG-0510, "Identification of Unresolved Safety Issues Relating to Nuclear Power Plants," U.S. Nuclear Regulatory Commission, January 1979.
[3] Letter to All Licensees of Operating Plants and Applicants for Operating Licenses and Holders of Construction Permits from U.S. Nuclear Regulatory Commission, "Control of Heavy Loads (Generic Letter 80-113)," December 22, 1980.
[4] NUREG-0612, "Control of Heavy Loads at Nuclear Power Plants Resolution of Generic Technical Activity A-36," U.S. Nuclear Regulatory Commission, July 1980.
[5] Letter to All Licensees of Operating Plants and Applicants for Operating Licenses and Holders of Construction Permits from U.S. Nuclear Regulatory Commission, "Control of Heavy Loads (Generic Letter 80-113)," December 22, 1980.
[6] NUREG-0612, "Control of Heavy Loads at Nuclear Power Plants Resolution of Generic Technical Activity A-36," U.S. Nuclear Regulatory Commission, July 1980.
[7] Letter to All Licensees of Operating Plants and Applicants for Operating Licenses and Holders of Construction Permits from U.S. Nuclear Regulatory Commission, "Control of Heavy Loads (Generic Letter 81-07)," February 3, 1981.
[8] Letter to All Licensees of Operating Plants and Applicants for Operating Licenses and Holders of Construction Permits from U.S. Nuclear Regulatory Commission, "Control of Heavy Loads (Generic Letter 80-113)," December 22, 1980.
[9] NUREG-0612, "Control of Heavy Loads at Nuclear Power Plants Resolution of Generic Technical Activity A-36," U.S. Nuclear Regulatory Commission, July 1980.
[10] NUREG-0606, "Unresolved Safety Issues Summary," U.S. Nuclear Regulatory Commission, Vol. 7 No. 3, August 1985.
[11] NUREG-0800, "Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants," U.S. Nuclear Regulatory Commission, (1st Ed.) November 1975, (2nd Ed.) March 1980, (3rd Ed.) July 1981.
[12] Letter to All Licensees for Operating Reactors from U.S. Nuclear Regulatory Commission, "Completion of Phase II of "Control of Heavy Loads at Nuclear Power Plants," NUREG-0612 (Generic Letter 85-11)," June 28, 1985. [ML031150689]
[13] Letter to All Licensees for Operating Reactors from U.S. Nuclear Regulatory Commission, "Completion of Phase II of "Control of Heavy Loads at Nuclear Power Plants," NUREG-0612 (Generic Letter 85-11)," June 28, 1985. [ML031150689]
Page Last Reviewed/Updated 06/24/2025