52. In pri,nciple, artiltery pieces of f55 mn- calibre or larger are nuclear- capable" loth the soviet union and the united states ha.ve in their regular a"my units several hundred. such artilIery pieces, a.s they are prirnarily intended to fire conventional shel-ls. Nucfear artillery she1ls for l'r5 ntt. and 203 rrn' pieces have been developed in the United States and are also deployed in Europe' They are renerally believed to have yields from a fraction of s. kiloton up to .] few kilotons. Some sources state without q-ualification that the Soviet Union also has these nuclear rnunitions. 53. Atomic denolition nunitions (ml,ts ) are desigred to fi:nction somevhat like conventional land mines, creatin4l craters and other obstacles to an advancin6l r'rr't v fhc TTnited States is knovn to have manufactured this type of nuclear erplosive, but any nuclear charge of suitable size could probably be quickly adapted for the purpose. IIo emplacement is knom to have taken place. 5)+" very few data are available on some naval nuclear-weapon systens 'whieh have for ma.ny years been said to exist at least in the United States alsenal. l4ost frequentty rdentioned are the Anerican ASROC and SUBROC ASII rocket -torpedoes rrith an allefled yield of I kt ' q/ Reportedly, there are also mrclear depth-charses r.ri t-h E t-n I o Ll- rri pl .1 r,ihether or not nuclear sea "rineS are at prer ent available anlrwhere is unclear ' 55" Europe is a zone of very high concentration of tactical nucfear weapons. An often quoted figure is that the United States disposes of about 7,000 such lreapons in Europe" in many depots in the territories of several countries. The Soviet Union is believed to possess more than 3-000 weapons of this kind for use in Europe " and costs of acquiring nuclear weapons
**Analysis**
The text appears to be discussing military and nuclear weapons, specifically the possession and deployment of nuclear-capable artillery pieces, atomic demolition munitions, and naval nuclear-weapon systems by the Soviet Union and the United States. The text also mentions the number of tactical nuclear weapons deployed in Europe. Given the focus on military and nuclear weapons, it seems likely that the text falls under the categories related to security and defense.

**Category**
Science and technology, International relations