United States Nuclear Regulatory Commission - Protecting People and the Environment

Access Controls for Spent Fuel Storage Pools

HPPOS-245 PDR-9111220092

See the memorandum from L. J. Cunningham to J. H. Joyner dated November 9, 1990. This memo provides guidance concerning the “establishment of locked high radiation areas.” Radioactive materials that could result in dose rates greater than 1000 mrem/hr are stored under water in a spent fuel storage (SFS) pool. These radioactive materials are sometimes contained in buckets hung from railings around the SFS pool. It is assumed that when the materials are stored in the pool, the dose rates above the pool in the vicinity of the stored materials are less than 100 mrem/hr. The health physics position was written in the context of 10 CFR 20.203, but it also applies to “new” 10 CFR 20.1601. HPPOS-106 contains a related topic.

HPPOS-016 states that because of the inaccessibility to personnel of the area in which radioactive materials are stored (under water), SFS pools are not considered to be high radiation areas and therefore the requirements of 10 CFR 20.203 (c) (2) [or 10 CFR 20.1601 (a)] do not apply. HPPOS-016 also states that when a diver enters the pool or upon movement of highly radioactive materials stored in the pool, proper health physics controls must be instituted.

Movement of radioactive material stored in the pool has the potential to create a high radiation area around the pool; however, a high radiation area is not created until movement of the material actually results in a radiation level, in an area that is accessible to personnel, that could result in a dose in excess of 100 mrem in any one hour. Therefore, the relative accessibility of radioactive material stored in buckets hung from railings around the pool is not applicable to the requirements of 10 CFR 20.203 (c) (2) [or 10 CFR 20.1601 (a)].

IE Information Notice 90-33, dated May 9, 1990, provides suggestions for radiological control considerations that can help minimize the possibility of unexpected exposure from radiation sources in SFS pools. The suggestions include: “Measures to ensure that highly radioactive objects stored under water at one end of a line whose other end is secured above the surface of the pool are not unexpectedly pulled to the surface.” Such measures may include locking mechanisms that prevent inadvertent and unauthorized withdrawal of such sources. This practice is not a regulatory requirement; however, the requirements for “Instructions to Workers” in 10 CFR 19.12 are applicable. Workers in SFS pool areas must “be kept informed of the storage, transfer, or use of radioactive materials” stored in the pool and must be instructed in “precautions or procedures to minimize exposure” that may result from this method of storage. Appropriate formal training and posting of signs that warn of the hazards of source withdrawal are among the ways to meet this requirement.

Regulatory references: 10 CFR 19.12, 10 CFR 20.203, 10 CFR

20.1601

Subject codes: 4.1

Applicability: Reactors

Page Last Reviewed/Updated Thursday, March 29, 2012